Regazzoni Daniele
Professore Ordinario
Università degli Studi di Bergamo
daniele.regazzoni@unibg.it
Sito istituzionale
SCOPUS ID: 24469250100
Orcid: 0000-0001-5533-7047
Pubblicazioni scientifiche
Abstract: Segmentation of anatomical components is a major step in creating accurate and realistic 3D models of the human body, which are used in many clinical applications, including orthopedics. Recently, many deep learning approaches have been proposed to solve the problem of manual segmentation, which is time-consuming and operator-dependent. In the present study, SegResNet has been adapted from other domains, such as brain tumors, for knee joints, in particular, to segment the femoral bone from magnetic resonance images. This algorithm has been compared to the well-known U-Net in terms of evaluation metrics, such as the Dice similarity coefficient and Hausdorff distance. In the training phase, various combinations of hyperparameters, such as epochs and learning rates, have been tested to determine which combination produced the most accurate results. Based on their comparable results, both U-Net and SegResNet performed well in accurately segmenting the femur. Dice similarity coefficients of 0.94 and Hausdorff distances less than or equal to 1 mm indicate that both models are effective at capturing anatomical boundaries in the femur. According to the results of this study, SegResNet is a viable option for automating the creation of 3D femur models. In the future, the performance and applicability of SegResNet in real-world settings will be further validated and tested using a variety of datasets and clinical scenarios.
Keywords: 3D modeling knee | automated segmentation | CNN | computer-aided design | deep learning | machine learning for engineering applications | MONAI framework | SegResNet | U-Net
Abstract: Introduction: Clinical gait analysis can be used to evaluate the recovery process of patients undergoing total hip arthroplasty (THA). The postoperative walking patterns of these patients can be significantly influenced by the choice of surgical approach, as each procedure alters distinct anatomical structures. The aim of this study is twofold. The first objective is to develop a gait model to describe the change in ambulation one week after THA. The secondary goal is to describe the differences associated with the surgical approach. Materials and methods: Thirty-six patients undergoing THA with lateral (n = 9), anterior (n = 15), and posterior (n = 12) approaches were included in the study. Walking before and 7 days after surgery was recorded using a markerless motion capture system. Exploratory Factor Analysis (EFA), a data reduction technique, condensed 21 spatiotemporal gait parameters to a smaller set of dominant variables. The EFA-derived gait domains were utilized to study post-surgical gait variations and to compare the post-surgical gait among the three groups. Results: Four distinct gait domains were identified. The most pronounced variation one week after surgery is in the Rhythm (gait cycle time: +32.9%), followed by Postural control (step width: +27.0%), Phases (stance time: +11.0%), and Pace (stride length: − 9.3%). In postsurgical walking, Phases is statistically significantly different in patients operated with the posterior approach compared to lateral (p-value = 0.017) and anterior (p-value = 0.002) approaches. Furthermore, stance time in the posterior approach group is significantly lower than in healthy individuals (p-value < 0.001). Conclusions: This study identified a four-component gait model specific to THA patients. The results showed that patients after THA have longer stride time but shorter stride length, wider base of support, and longer stance time, although the posterior group had a statistically significant shorter stance time than the others. The findings of this research have the potential to simplify the reporting of gait outcomes, reduce redundancy, and inform targeted interventions in regards to specific gait domains.
Keywords: Factor analysis | Gait analysis | Motion capture | Recovery of function | Surgical approach | Total hip replacement
Abstract: Total hip arthroplasty (THA) is a surgical procedure advised to treat end-stage osteoarthritis. There are several surgical approaches involving different biomechanical effects, potentially affecting the outcome. A possible consequence of THA is the Trendelenburg gait, which consists of a pelvis drop and trunk lean during walking due to a unilateral weakness of the hip abductors. Gait analysis can be useful in assessing the disorder. The purpose of the present research is twofold: i) to assess the Trendelenburg disease in patients undergoing THA through gait analysis; ii) to investigate the relationship between the disorder and surgical approaches. Patients’ gaits were recorded 7 days after THA surgery, using two Microsoft Kinect V2 sensors and virtual skeletons were reconstructed by iPi Soft software. A customized tool was developed to automatically identify walking phases and recognize characteristics compatible with the Trendelenburg gait. In addition to pelvic drop and trunk lean in the frontal plane, kinematic measurements are proposed for a more complete assessment of the Trendelenburg gait. These variables are found to be effective in highlighting the differences between surgical approaches.
Keywords: Gait Analysis | Motion Capture | Recovery of Function | Total Hip Arthroplasty | Trendelenburg Gait
Abstract: The correct execution of scanning protocols is crucial to ensure the quality of radiographic examinations. Recent advances in machine learning methods have opened up new possibilities for medical imaging. However, the potential of pose estimation models in this field is still largely unexplored. This study aims to address this gap by investigating the performance and an application of pose estimation in the context of X-ray image acquisition. To this goal, a pose estimation model was selected from a pool of state-of-the-art models. It was then trained on a dataset of 213 images of humans undergoing X-ray imaging. Despite the limited size of the dataset, the model achieved an AP of 0.902 and a near real-time inference speed of 7 FPS on CPU. The detection of landmarks through pose estimation enables the automatic assessment of pose adherence to prescribed imaging protocols. This automation can reduce human errors and alleviate the mental workload on radiologists. The results of this study highlight the potential of convolutional neural network-based pose estimation models to assist radiologists in performing X-ray imaging tasks effectively.
Keywords: Convolutional Neural Networks | Deep Learning | Optical Imaging | Pose Estimation | Radiography
Abstract: The logistics industry involves various processes in the warehouse work environment on a daily basis, such as handling, storage, and packing. Therefore, workers are often engaged in manual activities such as pushing, pulling and lifting loads. These types of movements are repetitive and, together with adverse physical factors of the environment, they affect employees’ health condition. The aim of this study is to test a proactive evaluation approach exploiting the potential of a professional virtual wall to simulate specific tasks performed in a warehouse to find the better solution in terms of working condition and productivity. The proposed framework includes the following steps: at first, it is required to design the virtual environment by means of 3D modelling tools; afterwards, simulation tests are performed by objectively assessing the physical working condition of the operator; finally, the valuable information are provided to improve the design of the workstation, based on the operator’s ergonomics. The framework is modular and can be scaled to complex industrial environments.
Keywords: Ergonomics | Logistics | Virtual Reality | Virtual Wall
Abstract: A bi-level analysis of computed tomography (CT) images of malignant pleural mesothelioma (MPM) is presented in this paper, starting with a deep learning-based system for classification, followed by a three-dimensional (3D) reconstruction method. MPM is a highly aggressive cancer caused by asbestos exposure, and accurate diagnosis and determination of the tumor’s volume are crucial for effective treatment. The proposed system employs a bi-level approach, utilizing machine learning and deep learning techniques to classify CT lung images and subsequently calculate the tumor’s volume. The study addresses challenges related to deep neural networks, such as the requirement for large and diverse datasets, hyperparameter optimization, and potential data bias. To evaluate performance, two convolutional neural network (CNN) architectures, Inception-v3 and ResNet-50, were compared in terms of their features and performance. Based on CT images, the second stage incorporates 3D volume reconstruction. The process is carried out by cropping, registering, filtering, and segmenting images. This study demonstrated the efficacy of the developed system by combining CNN optimizations with 3D image reconstruction. It is intended to improve the accuracy of MPM diagnosis and to assist in the determination of chemotherapy doses, both of which may result in improved outcomes for patients.
Keywords: 3D reconstruction | CNN | CT imaging | malignant pleural mesothelioma
Abstract: Background: Several studies have demonstrated the effectiveness of telerehabilitation. However, it remains unclear what proportion of people in need of rehabilitation can confidently use telecommunications networks and related devices. Objectives: The aim of this study is to estimate the proportion of patients who possess either the requisite digital literacy to perform telerehabilitation independently or have a family caregiver capable of providing effective support. Methods: Synthetic populations with a realistic kinship network (i.e. family trees) representative of European countries are built. Age, sex, and location-specific prevalence rates of rehabilitation needs and digital skills are combined to estimate the percentage of digitally literate patients and patients with digitally literate relatives. Results: In Europe, 86% of people in need of rehabilitation are potentially eligible for telerehabilitation. However, in four out of five cases, eligible patients over the age of 65 require caregiver support. Conclusion: Telerehabilitation has the potential to spread in Europe. Caregivers have an essential social role in ensuring sustainable access to telerehabilitation.
Keywords: Caregivers | Kinship Care | Sustainable Development | Telemedicine | Telerehabilitation
Abstract: Background: Heart failure (HF) is responsible for a high number of hospitalizations, caused by a progressive worsening quality of life. Telemedicine allows for better management of patients’ complex conditions, improving the care released. However, the risk of remaining at a testing stage often limits the integration of remote care in daily pathways for HF patients. The aim of this study is to outline the steps needed to integrate telemedicine activities into ordinary HF clinic practices. This methodology is applied to observe activities and trend improvements over a 12-month routine phase. Method: Three steps have been defined for an efficient introduction of remote care services in ordinary activities, integrating them with traditional in-person care: (i) introduction of temporary telemedicine projects, (ii) systematization of telemedicine pathways, and (iii) evaluation of monitoring phase. Observational data have been collected from structured interviews to show the rate of telemedicine activities achieved in clinical practice over the last year. Results: The methodology has been proposed in the HF clinic of the Italian hospital ASST Bergamo Est. After an initial testing phase, in which usability and user experience have been tested, four different remote activities were added: (i) telemonitoring for patients with an implantable device, (ii) follow-up televisits, (iii) nursing telephone support, and (iv) high-intensity telesurveillance pathways for patients after an HF acute event. During the last year, 218 telemonitoring pathways, 75 televisits, 500 telephone calls, and nine telesurveillance pathways have been performed. Success rates were high, and patients gave positive feedback. Conclusion: By integrating multiple telemedicine activities, it has been possible to better manage complex patients, keep track of disease progression, and improve their participation in care.
Keywords: daily practice | heart failure patients | remote care organization | telemedicine | telemonitoring | televisit | user experience
Abstract: In recent years, Additive Manufacturing (AM) proved to be extremely competitive in the production of small lots of pieces with high customization. Compared to subtractive production, AM allows to make less waste of material and reproduce highly complex components without increasing their costs. Some studies also assessed the environmental advantages of AM, which could be significant in the event of its future large-scale diffusion. However, an environmental assessment considering the aspects of hierarchical complexity that can be obtained with AM is missing in literature. This study bridges this gap by evaluating and comparing the environmental impacts resulting from the implementation of different design for AM options defined at different levels of detail, e.g. shape, cellular internal structure and infilling. For each option, the environmental impact arising from the mass and energy of manufacturing was calculated. The data were obtained through virtual simulations with commercial software for design for AM (i.e. nTopology) and experimentation with a 3D printer that produces pieces in polylactic acid (PLA). The obtained results highlighted the preponderant role of energy consumption deriving from the path of the print head in defining the environmental impacts, with respect to the quantity of material in the piece. In particular, we have seen how the shape and infill optimization (if the density is lower than 50%) reduce the environmental impacts, while the lattice structure optimization increases them, due to the more energy and time-consuming printing process.
Keywords: Design for Additive Manufacturing | Eco-assessment | Eco-design
Abstract: Nowadays, 10–34% of patients undergone Total Knee Arthroplasty (TKA) continues to have pain and reduced mobility. New technologies in TKA have been developed to reproduce the native anatomy, respecting the natural joint line, by means of customized implants or following the kinematic alignment. In this context, the present research aims at defining a method to create customized implants. In particular, three different situations have been studied. The first condition is the healthy knee, that is used as reference for further analysis. For the second situation, an off-the-shelf prosthesis has been virtually implanted, following the kinematic joint line. In the third solution, a custom-made knee implant has been created. In all the three cases, FEA has been performed to study how load transmission and stability change after TKA. To reach the goal, high resolution Magnetic Resonance (MR) images of a healthy knee have been employed. Three-dimensional models of the knee have been reconstructed through a segmentation process, starting from DICOM images. Hence, the three situations have been studied. Distribution of pressure and stress are comparable in the two solutions, since they both maintain the natural joint line. Improving the kinematic function is crucial to increase patient satisfaction. According to the patient’s anatomy, the surgeon can choose between the standard and the personalized prosthesis. The studied customized approach allows to overcome the limits of conventional TKA since it permits to create geometries, which accommodate a variety of anatomical variations.
Keywords: 3D modeling | Customized knee implants | FEA | Kinematic alignment
Abstract: Collaborative robots (cobots) are designed to directly interact with human beings within a shared workspace. To minimize the risk of musculoskeletal disease for the workers, a physical ergonomic assessment of their interaction is needed. Virtual reality (VR) and motion capture (Mocap) systems can aid designers in building low-hazard collaborative environments. This work presents a framework based on VR and Mocap systems for the ergonomic evaluation of collaborative robotic workstations. Starting from the 3D models of the cobot and workstation components, a virtual environment is built in Unity and ROS is employed to manage the cobot behavior. The physical ergonomics is evaluated by means of RULA methodology, exploiting the body tracking capabilities of the device Kinect Azure, a low-cost markerless Mocap system. The framework has been tested by building a virtual environment for collaborative control of flanges with different diameters. The worker interacts with a six-axis Nyro One to move parts on the workstation. The ergonomic assessment is performed in real-time, and a report is generated for later uses and evaluations. The proposed framework fosters the design of collaborative robotics workstations based on an objective assessment of ergonomics. The results of this research work allow planning future development steps for the emulation of more complex workstations with cobots and the use of augmented reality to evaluate how to modify existing workstations to introduce a cobot.
Keywords: Collaborative robots | Ergonomics | Motion capture | Virtual reality
Abstract: During past years, the pandemic has revealed the importance of having a solid care system prepared to face emergencies. In this context, digital solutions demonstrated a high potential in dealing with critical conditions and ensuring the delivery of care. However, telemedicine has not yet succeeded in becoming a stable part of ordinary care. The integration of innovative telemedicine technologies with a set of well-organized activities plays a crucial role in the release of high-quality services. Processes modeling before the introduction of telemedicine services is a leverage to prepare the base for an effective and efficient shift to digital care. Hence, the present research customizes a modeling technique in four steps for a preliminary analysis of processes where to introduce televisits. A special attention is given to the collection of consistent knowledge about care processes, often lack and incomplete in public hospitals scenarios. The approach has been applied to the AS-IS process of the heart failure clinic of a large Italian hospital before the introduction of televisits. Integrated Definition for Function Modeling (IDEF) diagrams have allowed the hierarchical decomposition of complex phases in simpler tasks, the acquisition of consciousness and the updating of information. Diagrams have been created and used as a source of a common language to discuss about weaknesses of the current process and its possible improvements. Obstacles to the upcoming televisits services have been objectively highlighted, such as the need to reduce employed applications, the removal of printed material and the streamlining of unnecessary operations.
Keywords: Healthcare processes | IDEF0 | Process modeling | Televisits
Abstract: Anterior Cruciate Ligament (ACL) is one of the most injured ligaments. Various researches have studied the relationship between ACL rupture and the bony morphology attempting to understand why ACL rupture occurs. The most investigated predisposing factors in the scientific literature are mainly related to the femoral intercondylar notch and the tibial plateau. The aim of the present research is to create a semi-automatic tool for assessing the risk of developing an ACL injury. A package, named ACL Morsky, has been created in 3D Slicer to follow the entire workflow. The process starts with the load of DICOM data. Three-dimensional models are reconstructed by means of segmentation. Then, five parameters, considered risk factors for the ligament rupture, are measured both in 2D images and on 3D models. A specific algorithm compares the measured values with the range in literature to evaluate the probability of developing an ACL injury. The physician is provided with a report for the patient and his/her risk factors. Knowing in advance the risk of rupture can help in reducing it with preventive plans.
Keywords: 3D Slicer | Knee Injury | Knee Risk Assessment | Ligament Risk Factors | Morphological Parameters
Abstract: This article proposes a design framework for additive manufacturing (AM) to solve contradictory design problems. Different structural features are selected within different levels of detail (e.g., cellular structures, infill, porosity) to realize the conflicting requirements and properly combined within the structure of the product. To do this a multilevel interpretation and classification of the options present in a commercial software of Design for AM was provided. Then, criteria to combine the different structural features within the structure of the product were proposed, starting from some principles of the TRIZ (i.e., Russian acronym for “Theory of Inventive Problem Solving”) method. The method was applied to design a dental prosthesis and the results, obtained by testing a simplified plastic sample were analyzed. The contradictory problem deals with the realization of both the mechanical resistance, during the chewing, and the thermal resistance to prevent the thermal dilatation during the workpiece finishing operations on machine tools. The sample designed with the proposed method exhibited better performances in both the requirements compared to another sample, made with a microstructure chosen in a completely random way.
Keywords: Design for Additive Manufacturing | Hierarchical complexity | Multilevel design | TRIZ
Abstract: Digital human modeling and gait analysis are essential for improving hip replacement surgery (HRS). In this study, Convolution Neural Networks (CNN) are used as a machine learning method to extract the most accurate stick-model from videos captured on a simple camera to represent gait and body components. We developed and tested multiple approaches to create an equitable skeleton model from an image. This process consists of two main parts: defining the joint locations using a CNN network in different architectures, and defining the connections into the final skeletons. A CNN has been trained, validated, and tested using the OpenPose software, which combines two different networks that have been tested on three data-sets for learning and evaluation. The results were satisfactory, but MobileNetV1 was evaluated for optimization of OpenPose computations and definitions. Several hyper-parameters were investigated to provide better representations. As a result of utilizing OpenPose methodology in conjunction with heavily optimized network design and post-processing code, and implementing MobileNet, the proposed solution has provided improved accuracy ratios.
Keywords: 2D Joint profile | CNN | Deep Learning | skeleton feature extraction
Abstract: Total knee arthroplasty (TKA) is the surgical procedure of choice for end-stage osteoarthritis. Even if it is widely performed, there is still dissatisfaction with the surgical procedure in about 20-30% of patients. Factors such as malalignment of the implant and the size of the components have been reported as the most common reasons for post-operative complaints. Custom-made prostheses have been introduced to replicate each individual joint geometry and kinematics. In this study, a novel approach is proposed to automate custom-made knee implant design. The aim is to create a pipeline, where customized implants can be designed automatically for a large number of patients, reducing the time for design. Firstly, a manual procedure for designing the implant is defined. The lower part of the femur is extruded with a thickness that matches with the natural anatomy of the patient and cut planes are used to design the customized femoral implant. Then, an automatic procedure is developed. For the purpose, a statistical shape model of femur, based on 33 patients, is created and employed. The procedure is tested with 5 study cases showing the potential of the methodology. Results will be furtherly validated on a larger scale.
Keywords: 3D Modelling | Customization | Human Modelling | Personalized | Statistical Shape Model | Total Knee Arthroplasty
Abstract: Logistic activities can cause long-term musculoskeletal problems due to repetitive and incorrect movements, heavy loads, and uncomfortable positions. Ergonomic evaluations are conducted to prevent these risks, optimize workstations, and work processes. Some studies use automatic evaluation of ergonomic indices or frameworks for optimizing workstations and logistics reorganization. However, optimization is often disconnected from real-world case studies. This research work validates a new approach that integrates an automatic ergonomic evaluation and optimization in real-world scenarios, comparing this analysis with traditional manual evaluation method. Our approach is applied to a real logistics case study using a wearable motion capture system and an interactive interface that displays the Digital Twin of the analyzed task. Results show that our approach provides a more accurate evaluation of the ergonomics and an evident time-saving.
Keywords: Ergonomics | Optimization | Warehouse Logistic
Abstract: This paper introduces an assistive system for diagnosing malignant pleural mesothelioma (MPM), a highly aggressive cancer caused by asbestos exposure. The system assists healthcare providers in accurately determining the tumor’s volume and the appropriate dose of chemotherapy to administer. It employs a bi-level process that uses machine learning and deep learning techniques to classify CT images of lungs and then calculate the tumor’s volume. The study addresses the challenges associated with deep nets, such as the need for large and diverse datasets, hyperparameter optimization, and potential data bias. Two CNN architectures, Inception-v3 and ResNet-50, were compared in terms of their features and performance, and three hyperparameters were optimized for each model to generate a broad range of training scenarios. To estimate the amount of cancer cells to target, CT images were used to calculate the tumor’s volume. This process involved image pre-processing, cropping volume, registering and filtering images, filling holes, segmentation, and 3D reconstruction. The results demonstrate that the developed system utilizing CNN optimizations and reconstruction of 3D images from CT images can benefit the treatment of MPM patients. The system has the potential to improve the accuracy of MPM diagnosis and the effectiveness of chemotherapy, ultimately improving patient outcomes.
Keywords: 3D volume reconstruction | CNN | CT imaging | Malignant Pleural Mesothelioma
Abstract: Segmentation of anatomical components is a critical step in creating accurate and realistic 3D models of the human body, which are employed in a wide range of clinical applications, particularly in orthopedics. Recently, many deep learning approaches have been proposed to solve the problem of manual segmentation. Among the available software for automatic segmentation, MONAI Label is a free open-source tool, which allows for the creation of annotated datasets and the development of AI-based annotation models for clinical assessment. In this context, the present study is designed to compare the performance of two well-known neural networks in segmenting knee bones. In spite of the fact that several studies have investigated the use of deep learning techniques for knee reconstruction, there is no consensus regarding the most effective method. In the present study, validation metrics are selected in order to assess the accuracy of the automated segmentation models in comparison with the ground truth data. Magnetic resonance images of 31 patients have been employed for the study. As result, U-Net shows better performance than the SegResNet in the automatic femur segmentation task.
Keywords: 3D Modelling Knee | Automated Segmentation | Deep Learning | SegResNet | U-Net
Abstract: This article presents a software platform to design serious games for the rehabilitation of severe memory loss by means of virtual reality (VR). In particular, the focus is on retrograde amnesia, a condition affecting patient’s quality of life usually after brain stroke. Currently, the standard rehabilitation process includes showing pictures of familiar environments to help memory recover, while the proposed rehabilitation solution aims at developing patient-specific serious games for memory loss starting from 3D scanning of familiar environments. The Occipital Structure sensor and the Skanect application have been used for the virtualization of the real objects and the environment. Instead of following the traditional approach to design a video game during which the game logic is specifically developed for a virtual scene and the software code is not meant to be recombined, a modular procedure has been designed using Unity to interface the virtual objects of each acquired environment without modifying the game logic. In addition, the developed solution makes available a set of software modules for patient’s monitoring and data management to automatically generate medical reports, which can be easily connected to each new serious game. A test has been performed to assess the main features of the VR platform and its usability recruiting ten testers. Medical personnel evaluated positively the platform, and they highlighted the importance of objective data to improve the ecological validity of the cognitive rehabilitation for retrograde amnesia.
Keywords: Neurological disorders | Serious game | Virtual reality
Abstract: Additive manufacturing processes, such as Laser Additive Manufacturing (LAM), has become increasingly established in metal-processing industry offering versatile possibilities for producing individualized components or lightweight structures. LAM machines offer ecological and economical potentials due to comparatively low power and material demand. In general, Additive Manufacturing (AM), has been considered an alternative to the traditional manufacturing techniques, such as Subtractive Machining (SM), because allows the creation of new, light and complex products with an innovative design and manufacturing. Sustainability assessment is essential to identify and select the best technology among the alternative candidates. Sustainability of LAM needs to be evaluated for finding an optimal compromise between technical development and sustainability performance. The Life Cycle Assessment (LCA) methodology is applied to investigate the sustainability of Laser Engineered Net Shaping (LENS) by comparing that of the Computer Numerical Control (CNC) machining. The aim of this research is to analyze and compare the environmental impact between additive and subtractive manufacturing. In particular, CNC (SM) and LENS (AM) technologies have been chosen. A common spur gear has been defined as a case study. Therefore, the analysis allows to define the ecological characteristics of a new production technology compared to a gold standard such as CNC machining. Hence, the advantages and disadvantages of the reviewed additive technology are exposed. The ReCiPe midpoint results, shows advantages in term of environmental impact for the LENS manufacturing process, in particular for the damage to resource indicator.
Keywords: Additive Manufacturing | Ecodesign | Environmental sustainability
Abstract: Total Knee Arthroplasty (TKA) is a widely performed surgical procedure, which is advised to treat knee osteoarthritis. However, the literature reported that 25% of the patients are unsatisfied by the functional outcomes after the intervention. The main causes seem to be the prosthesis malalignment and the anatomical mismatch between the prosthetic components and the different people anatomy. Even if there exist several commercial solutions, whose aim has always been to provide a reliable prosthesis with high survivorship, the most recent scientific literature is focusing its aim to improving the patients’ clinical outcome, kinematics and satisfaction. For this reason, three approaches have been experimented and then discussed with an orthopedic surgeon. Open-source software applications for 3D modelling have been exploited, such as 3D Slicer and Meshmixer. Starting from medical images, through the segmentation process, the 3D model of the knee has been reconstructed. For the first approach, standard off-the-shelf prosthesis have been used for the virtual planning of the intervention. To overcome the limits of this method, two more customized approaches have been experimented. The first one is based on the patient-specific resurfacing prosthesis that fits the patient’s anatomy, preserving the femur and maintaining the natural joint line. The third approach allows to create a customized prosthesis, that is a compromise between the two previous methods. Among the three previous procedures, the most suitable one can be chosen according to the patient’s anatomy, knee size and articular cartilage damage.
Keywords: 3D modelling | Customized knee prosthesis | Total knee arthroplasty planning
Abstract: Shoulder disorders are very common in the middle-aged population, due to several causes. The traditional diagnosis relies on the knowledge and the experience of the physician but a clinical misinterpretation in this early phase can have serious consequences for the patient’s health. The aim of this study is to investigate morphologicalshoulder parameters, as indicators of healthy or pathological conditions. In this way, it is possible to generate a quantitative report, based on measurements. It can be exploited as a medical support tool for physicians to either confirm the diagnosis, or to raise reasonable doubts, as far as the results differed. However, not all the shoulder disorders can be identified through this approach. Magnetic Resonance and Computed Tomography images of pathological shoulders have been employed for the study. The predefined morphological parameters have been measured on 2D medical images as well as from 3D reconstructed virtual model. Critical Shoulder Angle has been identified as the most significant parameter. It is well known that it is affected by Glenoid Inclination, Lateral Acromial Extension and Acromial Height. However, the contribution of each factor is not clear. Hence, a statistical analysis has been performed to understand how its sub-parameters influence it.
Keywords: Critical Shoulder Angle | Morphological Analysis | Patient Assessment | Shoulder Disorders
Abstract: Since every structure in the human body can vary, customization is important to choose the most appropriate medical option according to the patient. Total knee arthroplasty (TKA) is a surgical procedure for the knee replacement that has a high rate of patient's dissatisfaction. Indeed, conventional prostheses are based on anthropometric data that accommodate common knees. However, mismatch can occur due to anatomical variations among the individuals. Thanks to the advances in imaging techniques and 3D modeling, it is possible to create customized knee implants starting from medical images. In this context, the present research proposes a methodology to design a customized knee implant taking into account clinical (e.g., prosthesis alignment and surgical cuts) and technical parameters (e.g., materials) that have a direct impact on TKA performance and patient's satisfaction. Changing these parameters, different scenarios have been modeled and simulated to understand the most suitable combination. Finite element analysis (FEA) has been employed to simulate and compare the proposed customized models, changing the different clinical and technical parameters. Stress induced by different combinations of the parameters has been evaluated to choose the optimal solution among the eight proposed scenarios. The optimum is reached with a physiological alignment, with six femoral facets and the ultra-high molecular weight polyethylene (UHMWPE) tibial insert. The implant design maintains the natural joint line and allows preserving more bone. The material is the parameter that mostly influences the stress distribution.
Keywords: computer aided design | computer aided engineering | customized knee implant | femoral component optimization | finite element analysis | knowledge engineering | patient-specific knee prosthesis | total knee arthroplasty | virtual prototyping
Abstract: Since every structure in the human body can vary, customization is important to choose the most appropriate medical option according to the patient. Total knee arthroplasty (TKA) is a surgical procedure for the knee replacement that has a high rate of patient's dissatisfaction. Indeed, conventional prostheses are based on anthropometric data that accommodate common knees. However, mismatch can occur due to anatomical variations among the individuals. Thanks to the advances in imaging techniques and 3D modeling, it is possible to create customized knee implants starting from medical images. In this context, the present research proposes a methodology to design a customized knee implant taking into account clinical (e.g., prosthesis alignment and surgical cuts) and technical parameters (e.g., materials) that have a direct impact on TKA performance and patient's satisfaction. Changing these parameters, different scenarios have been modeled and simulated to understand the most suitable combination. Finite element analysis (FEA) has been employed to simulate and compare the proposed customized models, changing the different clinical and technical parameters. Stress induced by different combinations of the parameters has been evaluated to choose the optimal solution among the eight proposed scenarios. The optimum is reached with a physiological alignment, with six femoral facets and the ultra-high molecular weight polyethylene (UHMWPE) tibial insert. The implant design maintains the natural joint line and allows preserving more bone. The material is the parameter that mostly influences the stress distribution.
Keywords: computer aided design | computer aided engineering | customized knee implant | femoral component optimization | finite element analysis | knowledge engineering | patient-specific knee prosthesis | total knee arthroplasty | virtual prototyping
Abstract: Virtual Reality (VR) opens new frontiers in the rehabilitation field. Low-cost head mounted displays and motion capture systems are available and easily integrated in consumer technologies, such as laptops, smartphones, and tablets. The main limit of VR is related to its acceptance because the technologies are usually considered too complex for patients' daily rehabilitation. Furthermore, available VR hardware solutions are usually designed for generic categories of users and there is a considerable margin to specific pathologies or patients. This chapter presents the development of VR platforms for both cognitive and motor skills rehabilitation starting from physicians' requirements and usability issues. Three VR applications are described: a platform for cognitive rehabilitation of patients with severe memory loss, an application to test the level of extra-personal neglect, and a web platform for hand motor skill rehabilitation.
Keywords: Cognitive rehabilitation | Motor skills rehabilitation | Tele-rehabilitation | User-centered design | Virtual reality
Abstract: In manufacturing, ergonomic and productivity benefits may result from combining the sensing and dexterity of the human workers with the strength of collaborative robots (cobots). Anyway, manual tasks requiring repetitive motion or working with robots can cause musculoskeletal disorders especially of the hands. In such a context, this paper proposes a novel solution that includes both a full body inertial system and a dedicated solution for hand tracking. This allows implementing the standard methods for assessing ergonomic indexes and to introduce new advanced task analyses based on gesture evaluation. The benefits reached by the integrated system for body and hand tracking can be exploited in the virtual prototyping of collaborative workstation in the manufacturing domain. Different software packages have been considered to model and simulate the collaboration between the operator and the cobot. In particular, Unity and ROS are used to develop the virtual scene and control the cobot behavior and the HTC Vive Head Mounted Display (HMD) to interact with the virtual environment. Physical ergonomics is evaluated by using both a full body suit (XSENS) and sensorized gloves (MANUS). The solution has been applied to the simulation of a virtual production line where the operator collaborates with a six-axis cobot (NIRYO ONE). Test tasks require the operator to move and manage different objects and tools by simulating different types of grasping. Real-time feedback about ergonomics, in terms of posture evaluation and alerts in case of critical condition, is shown to the operator as well as the automatic generation of reports for the post-process evaluation of the entire process. The results show how the use of these tools can be effective in the ergonomic evaluation of a collaborative robotic workstation which requires manual tasks.
Keywords: collaborative robot | hand-tracking | motion capture | Physical ergonomics | wearable devices
Abstract: The rehabilitation process after stroke may exhibit some limits regarding physical therapy adherence and there could be a lack of patients’ motivation and trust impacting on the quality of the rehabilitation procedure. This research work aims at introducing a specific interactive design method to develop rehabilitation tools based on the medical knowledge and VR devices to recover motor skills of patients’ hands after stroke and to increase the patients’ adherence. The method we propose consists of three main steps: medical requirement analysis, identification of ICT tools, and medical data management. A case study related to hand rehabilitation is also presented.
Keywords: Hand-tracking devices | Leap motion device | Stroke rehabilitation | Virtual reality
Abstract: In recent years, the use and demand of bicycles have increased thanks to the growing attention to the environment and due to the COVID-19 pandemic situation. At the same time, the design of the bicycles has remained substantially unchanged, improving in materials and components technology. In the off-road sector, two diametrically opposed categories have emerged in terms of comfort and pedalling efficiency. The goal of this research is to introduce a first methodological approach for the optimization of a mountain bike frame. The behaviour of the developed frame aims to combine the pedalling benefits now available only in different and non-comparable bicycle configurations. The first step concerns the modelling of a generic off-road bicycle frame, then its behaviour has been simulated for specific load cases. Subsequently, the part of the bicycle that best performed the double function of compliance and rigidity has been sought through an analysis of the strain energy using FE simulations. Hence, the reference region has been topologically optimized to provide adequate chassis travel performance. The analysis scheme has been iteratively repeated also on other parts of the frame until an acceptable solution is obtained for the utilize presented. The final configuration permits a rear tube and bottom bracket displacement of 10.4 mm and 2.4 mm compared to the 0.5 mm and 0.4 mm of the original frame respectively. The approach described can be proposed as a support for the search for an innovative design for products with unchanged geometries due to the inertia of the designers. At the same time, this methodology aims to expand the possible use of topological optimization, moving away from the classic constraint schemes present in various software.
Abstract: Collaborative robotics, or Human-Robot Collaboration (HRC), is a challenging topic characterized by multidisciplinary approaches. Many researchers are facing this innovative manufacturing system studying several aspects such as task allocation, facility layout problem and timing. Above all, one of the most important issues in collaborative robotics is the wellbeing of the operator collaborating with the robot system during the different phases of the process. The added value of a collaborative workplace respect to the manual and automatic workplaces is strictly correlated to a safe and ergonomic interaction between the operator and the robot. Indeed, the combination of robot and operator skills lead to a higher level of accuracy and flexibility. Thus, assessing operator's working conditions requires the acquisition, eventually in real time, of relevant parameters such as posture, movements, and interactive tasks. This may require the adoption of existing metrics proposed by standard evaluation guidelines, as well as the introduction of new or modified prescription to consider the presence of the robot. The ergonomics analysis in collaborative robotics is evaluated by considering both physical and cognitive aspects of the operator during the interaction with the robot. The research work aims to carry out a scientific bibliometric literature review (BLR) about the ergonomics analysis of collaborative workplaces, and to identify methods and tools for the physical and cognitive ergonomics assessment that can be adopted in collaborative robotics. The search has been accomplished using the Scopus database by means of a set of key words specifically defined to investigate the ergonomics in the collaborative robotics. The review provides a sharp classification, a critical analysis of the most relevant contributions in this field so that emerging trends for future development can be defined and discussed.
Keywords: Bibliometric literature review (blr) | Cognitive ergonomics | Human-robot interaction (hri) | Humanrobot collaboration (hrc) | Physical ergonomics
Abstract: The paper presents a method to develop Virtual Reality (VR) platforms based on serious games for the rehabilitation of severe memory loss. In particular, it is related to retrograde amnesia, a condition affecting patient's quality of life usually caused by brain stroke. Nowadays, the standard rehabilitation process consists in showing pictures of patient's familiar environments in order to recover the memory. Past research works have investigated the use of 3D scanners for the virtualization of real environment and virtual reality for the generation of more immersive interaction to design serious games for neurocognitive rehabilitation. Reached results highlighted a time-consuming development process to interface each new environment with the game logic specifically developed for the serious games. Furthermore, a complete VR platform must also consider the medical monitoring and the data management oriented to a more objective medical assessment. The proposed method allows the design of VR platforms based on patient-specific serious games for memory loss starting from the 3D scanning acquisition of familiar environments. The 3D acquisition is performed using the Occipital Structure Sensor and the Skanect application. A modular procedure has been designed to interface the virtual objects of each acquired environment with the modules of the game-logic developed with Unity. The immersive Virtual Reality is based on the use of the HTC Vive Pro head mounted display. Furthermore, the method permits to associate the patient-specific serious game to a set of software modules for the medical monitoring and the data management for the generation of reports useful for the evaluation. The solution has been evaluated by measuring the time needed to develop a whole VR platform for two different familiar environments. Less than 5 hours are required to complete the design process.
Keywords: 3D scanner | Brain stroke | Memory loss | Rehabilitation | Serious games | Virtual reality
Abstract: Marker-less motion capture (MOCAP) systems based on consumer technology simplify the analysis of movements in several research fields such as industry, healthcare and sports. Even if the marker-less MOCAP systems have performances with precision and accuracy lower than the marker-based MOCAP solutions, their low cost and ease of use make them the most suitable tools for full-body movements analysis. The most interesting category is relative to the use of RGB-D devices. This research work aims to compare the performances of the last two generations of Kinect devices as marker-less MOCAP systems: Microsoft Kinect v2 and Azure devices. To conduct the tests, a list of specific movements is acquired and evaluated. This work measures the improvements of the Azure in tracking human body movements. The gathered results are presented and discussed by evaluating performances and limitations of both marker-less MOCAP systems. Conclusions and future developments are shown and discussed.
Keywords: Accuracy | Kinect Azure | Kinect V2 | Marker-less MOCAP systems
Abstract: Retrograde amnesia is a severe memory loss dramatically affecting patient’s quality of life. Traumatic brain injuries, strokes, degenerative processes or metabolic disorders are the main causes. At present, rehabilitation tries to recover patients’ memory by means of neuro-cognitive exercises guided by a physiotherapist. Unfortunately, the adherence to these rehabilitation exercises drops when patients are discharged from hospital. Furthermore, conventional rehabilitation is usually performed using standard exercises, which are not customized to each patient. The reproducibility of real environments and situations is a crucial feature to guarantee the efficacy of neuro-rehabilitation and it is defined as ecological validity. Ecological validity is important for making the exercises useful to re-learn specific information and for performing daily activities with the lowest effort. Nowadays, the traditional rehabilitation for retrograde amnesia is based on a set of pictures shown to the patient to remember or learn familiar environments, such as his/her home. This approach is very limiting because the patient can see few points of view of the home without learning and memorizing how to move and get into a specific room. Therefore, the traditional approach has a low ecological validity. The advent of innovative technology, like 3D scanners and virtual reality, permit the design of innovative solutions that virtually replicate patient’s home. This research work presents a novel procedure to design serious games for neuro-cognitive rehabilitation for patient with retrograde amnesia. The proposed procedure exploits low-cost and free technologies; in particular, the Occipital Structure sensor has been chosen as 3D scanner to acquire the 3D indoor environments, which are used inside Unity to develop the game logic of the serious games. The HTC Vive Pro head mounted display has been used to interact with the serious games in an immersive way. The designed procedure makes available a set of Unity scripts to develop the serious game for new patients by changing only the 3D environment (i.e., patient’s house). The procedure has been tested by creating three different serious games and the total time to create them can be approximated to a working day. The obtained results have been shown to medical personnel who have evaluated the proposed approach with a high ecological validity and decided to plan future medical tests by involving patients.
Keywords: Blender | Ecological validity | Occipital Structure sensor | Rehabilitation | Retrograde amnesia | Unity | Virtual reality
Abstract: Background and Objective: The paper presents a novel procedure based on 3D scanning and 3D modelling to automatically assess linear and volumetric measurements of an arm and to be further applied to patients affected by post breast cancer lymphedema. The aim is the creation of a virtual platform easily usable by medical personnel to get more objective evaluations during the lymphedema treatment. Methods: The procedure is based on the 3D scanning of the arm using the Occipital Structure Sensor and an ad-hoc developed application, named Lym 3DLab. Lym 3DLab emulates the traditional measurement methods, which consist in taking manual circumference measurements or using the water displacement method. These measurements are also used to design the compression stockings, the typical orthopaedic device used for lymphedema treatment. A validation test has been performed to compare the measurements computed by Lym 3DLab with both water displacement and manual circumference measurements. Eight volunteers have been involved who are not affected by lymphedema. Furthermore, a specific usability test has been performed to evaluate the 3D scanning procedure by involving four physiotherapists. Results: The comparison between the volumes has highlighted how all the 3D acquired models have their volumes inside a range of acceptability. This range has been defined by considering the sensitivity error of the tape measure used to measure the water displacement. The comparison between the perimeters of cross sections computed with Lym 3DLab and the circumference measurements has shown results that are very accurate with an average difference of 2 mm. The measure errors have been considered negligible by the medical personnel who have evaluated the proposed procedure more accurate than the traditional ones. The test with physiotherapists has shown a high level of usability of the whole virtual environment, but the 3D scanning procedure requires an appropriate training of the personnel to make the 3D acquisition as fast and efficient as possible. Conclusions: The achieved results and the physiotherapists’ feedback allow planning a future test with patients affected by lymphedema in collaboration with the hospital. A further test has been planned to use the computed measurements to design orthopaedic compression stockings.
Keywords: 3D scanning | Arm Volume | Circumference Measurement | Lym 3DLab | Lymphedema | Occipital Structure Sensor
Abstract: The research work presents a specific procedure to evaluate the performance of soccer goalkeepers by means of a marker-less motion capture (Mocap) system based on a set of 8 GoPro active cameras. The layout of the sensors and the calibration phase have been defined to be easily replicated and not to interfere with athletes and trainers during the exercises. The proposed solution has been tested in collaboration with goalkeeper coaches, who made available the knowledge about conventional training exercise. The Mocap system has been tested by involving two goalkeepers and a coach. The results have been elaborated and the outcomes have been considered interesting by experts. Furthermore, the adopted technology for motion capture and elaboration could be evaluated for an application to the rehabilitation process of an athlete after an injury, to determine his stage of recovery and the most suitable work to be done.
Keywords: Active camera | Goalkeepers training | Kinematic data analysis | Marker-less motion capture | Outdoor motion capture | Sports technology
Abstract: In physical rehabilitation, motion capture solutions are well-known but not as widespread as they could be. The main limit to their diffusion is not related to cost or usability but to the fact that the data generated when tracking a person must be elaborated according to the specific context and aim. This paper proposes a solution including customized motion capture and data elaboration with the aim of supporting medical personnel in the assessment of spinal cord-injured (SCI) patients using a wheelchair. The configuration of the full-body motion capturing system is based on an asymmetric 3 Microsoft Kinect v2 sensor layout that provides a path of up to 6 m, which is required to properly track the wheelchair. Data elaboration is focused on the automatic recognition of the pushing cycles and on plotting any kinematic parameter that may be interesting in the assessment. Five movements have been considered to evaluate the wheelchair propulsion: the humeral elevation, the horizontal abduction of the humerus, the humeral rotation, the elbow flexion and the trunk extension along the sagittal plane. More than 60 volunteers with a spinal cord injury were enrolled for testing the solution. To evaluate the reliability of the data computed with SCI APPlication (APP) for the pushing cycle analysis, the patients were subdivided in four groups according to the level of the spinal cord injury (i.e., high paraplegia, low paraplegia, C7 tetraplegia and C6 tetraplegia). For each group, the average value and the standard deviation were computed and a comparison with similar acquisitions performed with a high-end solution is shown. The measurements computed by the SCI-APP show a good reliability for analyzing the movements of SCI patients’ propulsion wheelchair.
Keywords: Automatic pushing analysis | Markerless motion capture | RGB-D sensors | SCI patients
Abstract: Motion capture (Mocap) is applied to motor rehabilitation of patients recovering from a trauma, a surgery, or other impairing conditions. Some rehabilitation exercises are easily tracked with low-cost technologies and a simple Mocap setup, while some others are extremely hard to track because they imply small movements and require high accuracy. In these last cases, the obvious solution is to use high performing motion tracking systems, but these devices are generally too expensive in the rehabilitation context. The aim of this paper is to provide a Mocap solution suitable for any kind of exercise but still based on low-cost sensors. This result can be reached embedding some artificial intelligence (AI), in particular a convolutional neural network (CNN), to gather a better outcome from the optical acquisition. The paper provides a methodology including the way to perform patient's tracking and to elaborate the data from infra-red sensors and from the red, green, blue (RGB) cameras in order to create a user-friendly application for physiotherapists. The approach has been tested with a known complex case concerning the rehabilitation of shoulders. The proposed solution succeeded in detecting small movements and incorrect patient behavior, as for instance, a compensatory elevation of the scapula during the lateral abduction of the arm. The approach evaluated by medical personnel provided good results and encouraged its application in different kinds of rehabilitation practices as well as in different fields where low-cost Mocap could be introduced.
Keywords: Artificial intelligence | Engineering informatics | Human computer interfaces/Interactions
Abstract: This paper presents an approach for monitoring exercises of hand rehabilitation for post stroke patients. The developed solution uses a leap motion controller as hand-tracking device and embeds a supervised machine learning. The K-nearest neighbor methodology is adopted for automatically characterizing the physiotherapist or helper hand movement resulting a unique movement pattern that constitutes the basis of the rehabilitation process. In the second stage, an evaluation of the patients rehabilitation exercises results is compared to the movement pattern of the patient and results are presented, saved and statistically analyzed. Physicians and physiotherapists monitor and assess patients’ rehabilitation improvements through a web application, furthermore, offer medical assisted rehabilitation processes through low cost technology, which can be easily exploited at home. Recorded tracked motion data and results can be used for further medical study and evaluating rehabilitation trends according to patient’s rehabilitation practice and improvement.
Keywords: Hand rehabilitation | K-nearest neighbor | Leap motion controller
Abstract: This chapter presents an overview of the virtual humans/digital human models (DHMs) that can be considered along the design and manufacturing processes. It first introduces a brief historical description, as well as the main problems to be faced and the potential of such models. Then, the chapter presents a taxonomy that subdivides DHMs into five main categories, highlighting the different levels of human model details and their applications. The integration of DHMs with virtual/augmented reality technology and motion capture systems is also considered respectively to improve the level of interaction and realism within the virtual environment and to drive the virtual human and facilitate the evaluation of comfort and prediction of injuries that could rise when executing a task. The chapter also describes applicative examples of each type of DHM for both design and manufacturing.
Keywords: Augmented reality technology | Digital human models | Manufacturing processes | Motion capture systems | System design | Virtual human models | Virtual reality technology
Abstract: In the last past years, computer-Aided technologies to improve existing products by widening the design space have been largely investigated. Topology optimization and generative design are two of the most representative technologies of such kind. This paper aims at investigating the use of generative design and topology optimization techniques to improve products whose design has not changed radically over the years. The product under investigation is a disk brake floating caliper that is the most common solution for commercial vehicles. In general, increasing the stiffness of the floating caliper while keeping its weight under control is desirable both from performance and fuel consumption point of view. The solution here proposed aims at exploiting two new ways to approach the engineering design process and evaluate which one is more suitable for problems of this kind. Starting from the original carrier shape, acquired with laser scanning, the two technologies have been applied on the same initial conditions. The initial design space volume corresponds to the acquired shape, the loads and the constraints for the simulation have been drawn reasonably to resemble the actual operating conditions. Keeping the input parameters constants, two different off-The-shelf software packages have been used to perform the computation and with the objective of maximizing the stiffness of the carrier while reducing its mass. The comparison and the improvements on the final designs have been drawn taken as reference to the original caliper..
Abstract: In the last years, the advent of low-cost markerless motion capture systems fostered their use in several research fields, such as healthcare and sport. Any system presents benefits and drawbacks that have to be considered to design a Mocap solution providing a proper motion acquisition for a specific context. In order to evaluate low-cost technology, this research work focuses on the evaluation of the accuracy of two categories of devices: The RGB active cameras and the RGB-D, or depth sensors devices. In particular, GoPro Hero 6 active cameras and Microsoft Kinect v2 devices have been selected as representative of the two categories. In particular, this work evaluates and compares the performances of the two systems used to track the position of human articulations. The two devices have been chosen among those available on the market after a state of the art has been completed. Before starting with the campaign of acquisition, the number of sensors and their layout have been designed to optimize the acquisition with both mark-less Mocap systems. Their comparison is based on a list of specific movements of upper and lower limbs. Each movement has been acquired simultaneously, to guarantee the same test conditions. The results have been organized, compared and discussed by evaluating performances and limitations of both solutions related to specific context of use. Conclusions highlight the best candidate technology..
Keywords: Accuracy | active cameras | GoPro | Markerless Mocap systems | Microsoft Kinect
Abstract: Total Knee Arthroplasty is one of the most commonly performed orthopedic procedures and it is expected to grow in the next future . In the last past years, computer-assisted procedures represent one of the trends that are transforming the way of practicing medicine. Cornering the Total Knee Arthroplasty, digital models of the joints have been used to carry out simulation of their kinematics and mechanical performance. Whilst for the 3D digital reconstruction of the patient geometry several studies have been conducted, an approximated geometry of the prosthesis has been several times employed, with undeniable consequences on the final results. This paper aims at comparing two non-contact reverse engineering technologies to acquire the shape of femoral components employed for total knee arthroplasty. A high-level device (Konika Minolta Vivid 9i) and a mid-low cost laser (NextEngine) has been compared. For the comparison, a systematic procedure of acquisition and elaboration of the results has been adopted in order to have as unbiased as possible results. The procedure involves the use of the proprietary software of the scanners for the elaboration of the raw data and the meshing procedure has been kept the same for all the models. Since the as-is acquired mesh is of high-resolution, a decimation procedure has been carried out in order to make the 3D models lighter and easier to be handled. Once the decimation procedure has been evaluated comparing the original and the simplified models to one another, the digitalized models have been compared with the measurements taken from a coordinate measuring machines. As a preliminary result, the two lasers seem to be adequate to accomplish the reverse engineering process as required by this application. Of course, the mid-low cost laser would be preferable whether the performance will be confirmed to be (statistically) equal.
Abstract: The research work presents a preliminary study to create a virtual reality platform for the medical assessment of spatial extrapersonal neglect, a syndrome affecting human awareness of a hemi-space that may be caused by cerebral lesions. Nowadays, the extrapersonal neglect is assessed by using real objects positioned in the space around the patient, with a poor capability of repetition and data gathering. Therefore, the aim of this research work is the introduction of a virtual reality solution based on consumer technology for the assessment of the extrapersonal neglect. By starting from the needs of the involved medical personnel, an online serious-game platform has been developed, which permits to perform a test and a real-time evaluation by means of objective data tracked by exploited technologies, i.e. an HTC Vive Pro head mounted display and ad-hoc IT solutions. The test is based on a virtual environment composed by a table on which twenty objects have been placed, ten on the right side and ten on the left side. The whole 3D virtual environment has been developed using low-cost and free development tools, such as Unity and Blender. The interaction with the virtual environment is based on voice recognition technology, therefore the patient interact with the application by pronouncing the name of each object aloud. The VR application has been developed according to an online gaming software architecture, which permits to share the 3D scene by exploiting a Wi-Fi hotspot network. Furthermore, the on-line gaming software architecture allows sending and receiving data between the doctor's laptop and the VR system used by the patient on another laptop. The therapist can see through his/her personal computer a real time faithful replica of the test performed by the patient in order to have a fast feedback on patient’s field of view orientation during the evaluation of 3D objects. A preliminary test has been carried out to evaluate the ease of use for medical personnel of the developed VR platform. The big amount of recorded data and the possibility to manage the selection of objects when the voice commands are not correctly interpreted has been greatly appreciated. The review of the performed test represents for doctors the possibility of objectively reconstructing the improvements of patients during the whole period of the rehabilitation process. Medical feedback highlighted how the developed prototype can already be tested involving patients and thus, a procedure for enrolling a group of patients has been planned. Finally, future tests have been planned to compare the developed solution with the Caterine Bergero Scale to define a future standardization.
Keywords: Extrapersonal neglect | Head mounted display | Neglect assessment | Virtual reality
Abstract: This research work presents a preliminary study for the assessment of lymphedema using low-cost 3D scanning and modelling technology. The aim is to develop a methodology to measure the anatomical key features of the upper limbs lymphedema using a 3D scanning technology and an ad-hoc developed application, named Lym 3DLab. The application is able to automatically measure both perimeters of cross sections and volumes of arm segments for medical evaluation and design of compression stockings using the upper limb polygonal mesh. The scanning procedure is based on a Microsoft Kinect v1 as scanner and the low-cost Skanect tool, which creates the polygonal mesh of the 3D acquisition. Lym 3DLab has been developed using open-source Software Development Kits, such as Qt and Visualization Toolkit. The acquired volumes have been compared with the water displacement method, which is considered the gold standard for measuring volumes of limbs affected by lymphedema. A preliminary test has been performed to compare volumes measured using the developed procedure with the gold standard. Five volunteers have been involved who are not affected by lymphedema. The arm volume measured with water displacement have been compared with the volume computed using 3D model of arm in Lym 3DLab. The range of differences is between −6,75 cm3 and 9,40 cm3. Reached results are the base for planning further test with a large number of patients affected by lymphedema in collaboration with a hospital.
Keywords: 3D scanning | Automatic measurement of arm volume | Breast cancer | Lymphedema | Microsoft Kinect | Upper limb modeling
Abstract: Motion capture (Mocap) systems are considered more and more interesting for the assessment of rehabilitation processes. In fact, medical personnel are increasingly demanding for technologies (possibly low-cost) to quantitatively measure and assess patients’ improvements during rehabilitation exercises. In this paper, we focus the attention on the assessment of rehabilitation process for injured shoulders. This is particularly challenging because the recognition and the measurement of compensatory movements are very difficult during visual assessment and the movements of a shoulder are complex and arduous to be captured. The proposed solution integrates a low-cost Mocap system with video processing techniques to allow a quantitative evaluation of abduction, which is one of the first post-surgery exercises required for shoulder rehabilitation. The procedure is based on a set of open-source software tools to measure abduction and evaluate the correctness of the movement by detecting and measuring compensatory movements according to the parameters commonly considered by the physicians. Finally, a preliminary results and future works are presented and discussed.
Keywords: Embedded Knowledge | Medical assessment | Microsoft Kinect v2 | Motion Capture | Post-surgery shoulder
Abstract: A 3D sketching system is presented for transforming an ideation to an actual CAD model using Human Computer Interaction (HCI). The system uses a Leap motion controller to capture human gestures, and translated them by a recognition model. The pinch and pull gestures are used to represent actions for flexible manipulations on control points coordinates of NURBS surfaces. The continuous motion of the designers hands is converted to morphological/geometrical and mathematical values. Both cases of single and dual hands are developed, offering the designer a variety of resolution tools to convey their ideas and creativity.
Keywords: 3D sketching | Human Computer Interaction Design | Leap Motion controller | NURBS surfaces
Abstract: Among rising technology in medical field, methods and solutions of reverse engineering have a high impact as a new possibility for improving the traditional processes to design prosthesis and orthoses. Furthermore, reverse engineering solutions allows managing a big amount of patient's data, which can be also exploited for making the medical assessment during rehabilitation activities more objective and measurable. In particular, innovative technologies permit to manage big amount of data coming from several IT devices in order to better understand the correlation between technical aspects and human factors. These IT devices can be exploited through customized software applications, which are able to combine many data types (e.g. 3D scanners, motion capture systems and pressure sensors). In this research work, the attention is focused on the design of lower limb prosthesis around the digital human model of the patient. We present a virtual platform composed by an ad-hoc developed application for customizing the prosthesis according to patients' life style and medical knowledge as well as for visualizing pressure on patient's limb while evaluating his/her gait in a unique virtual knowledge-guided environment. Such applications are conceived to be usable by non IT experts, and all information are directly visualized on the digital human model of the amputee. The first part of the paper introduces the whole platform to design lower limb prosthesis using low-cost technologies. Then, the virtual gait analysis tool is described. Finally, tests and conclusion are discussed.
Keywords: 3D modelling | Health informatics | Marker-less motion capture system | Pressure data | User centered design
Abstract: This scientific work aims at developing an innovative virtual platform to design lower limb prosthesis centered on the virtual model of the patient and based on a computer-aided and knowledge-guided approach. The main idea is to develop a digital human model of the amputee to be used by the prosthetist in a full virtual environment in which a platform provides a set of interactive tools to design, configure, and test the prosthesis. This virtual platform permits to design and configure the whole prosthesis, in particular, the 3D model of the assembled prosthesis, crucial to define the prosthesis setup and patient’s walking performance. An ad-hoc computer-aided design system has been developed in house to design the 3D model of the socket according to traditional operations made by technicians during traditional manufacturing process. Moreover, a finite element model has been defined to study the contact between residual limb and socket. The resulting 3D model of the socket can be realized by exploiting multimaterial additive manufacturing technology. Finally, the developed platform also permits to handle contact pressures and patient’s gait data in a unique application through the use of a low-cost motion capture (MOCAP) system. The whole platform has been tested with the help of an Italian orthopedic laboratory. The developed platform is a promising solution to develop the check socket, and the application may be used also for training purpose for junior orthopedic technicians.
Keywords: Low-cost MOCAP system | Lower limb prosthesis | Pressure analysis | Socket design and 3D modeling
Abstract: This work proposes a human computer interface system using a motion capture device, for assisting in CAD modeling and designing. The leap motion controller input data serves as an interactive tool which is transformed to surface representation of NURBS surfaces. Acquiring the sensor data is done by analyzing the images using a feature recognition module which in this work was updated and enhanced. Joints of hands and fingers are sufficed, and define recognized 3D image of a human hand. To use relevant information from the Leap Motion device, it is mandatory to interpret and map the input sensor data into 3D software coordinate system. This is done by implementing various transformations and a normalization procedures. Methods corresponding between these representation are developed in this work, to reduce noise thus providing accuracy. The DOF provided by the definition of the NURBS parametric surfaces and the Leap Motion Controller provide flexible design characteristics.
Keywords: Human Computer Interaction | Leap Motion Controller | NURBS surfaces | Virtual CAD
Abstract: Nowadays, healthcare centers are not familiar with quantitative approaches for patients’ gait evaluation. There is a clear need for methods to obtain objective figures characterizing patients’ performance. Actually, there are no diffused methods for comparing the pre- and post-operative conditions of the same patient, integrating clinical information and representing a measure of the efficiency of functional recovery, especially in the short-term distance of the surgical intervention. To this aim, human motion tracking for medical analysis is creating new frontiers for potential clinical and home applications. Motion Capture (Mocap) systems are used to allow detecting and tracking human body movements, such as gait or any other gesture or posture in a specific context. In particular, low-cost portable systems can be adopted for the tracking of patients’ movements. The pipeline going from tracking the scene to the creation of performance scores and indicators has its main challenge in the data elaboration, which depends on the specific context and to the detailed performance to be evaluated. The main objective of this research is to investigate whether the evaluation of the patient's gait through markerless optical motion capture technology can be added to clinical evaluations scores and if it is able to provide a quantitative measure of recovery in the short postoperative period. A system has been conceived, including commercial sensors and a way to elaborate data captured according to caregivers’ requirements. This allows transforming the real gait of a patient right before and/or after the surgical procedure into a set of scores of medical relevance for his/her evaluation. The technical solution developed in this research will be the base for a large acquisition and data elaboration campaign performed in collaboration with an orthopedic team of surgeons specialized in hip arthroplasty. This will also allow assessing and comparing the short run results obtained by adopting different state-of-the-art surgical approach for the hip replacement.
Abstract: In the last years, the advent of innovative technologies for tracking human motions is increasing the interest of physicians and physiotherapist, who would like to introduce new instruments for a more objective assessment of the rehabilitation processes. At present, many motion tracking systems have been developed and their ease of use and low-cost may represent the key aspects for which these systems could be really adopted both in rehabilitation centers and in rehabilitation programs at home. Several research studies confirmed the importance of continuing rehabilitation programs at home with the aim to maintain patients’ health condition at a suitable level for daily life activities. Physicians and physiotherapists need methods and tools, which can be simply adaptable for each type of patients’ category and type of rehabilitation according to the assessed pathology. For achieving this need, the technology has to be suitable for both the patient side and medical personnel side. The most suitable technology for the patients are motion tracking devices which can be used through traditional IT, such as laptops, smartphones and tablets. Also for medical personnel the ease of use is very important, physicians would like to check the patient’s rehab exercises according to their medical knowledge by exploiting daily life technology. This research work investigates on which are the best user-friendly programming tools and low-cost technology for 3D hand and finger tracking for the development of a serious game for rehabilitation exercises. The tasks are designed according to physiotherapists’ recommendations, in order to be customizable for any single user. The following sections will describe the method, the tools adopted, and the application developed.
Keywords: Hand tracking | Leap motion device | Low-cost technology | Post-stroke rehabilitation | Unity
Abstract: Low cost marker-less motion capture (Mocap) systems can be considered an interesting technology for the objective assessment of rehabilitation processes. In particular, this paper presents a feasibility study to introduce a Mocap system as a tool to assess shoulder rehabilitation. The movements of a shoulder are complex and challenging to be captured with a marker-less system because the skeleton avatar usually oversimplifies shoulder articulation with a single virtual joint. The designed solution integrates a low-cost Mocap system with image processing techniques and convolutional neural networks to automatically detect and measure potential compensatory movements executed during an abduction, which is one of the first post-surgery exercises for shoulder rehabilitation. First, we introduce the main steps of a reference roadmap that guided the development of the Mocap solution for rehab assessment of injured shoulder. Then, the acquisition of medical knowledge is presented as well as the new Mocap solution based on the integration of convolutional neural networks and 2D motion tracking techniques. Finally, the application which automatically evaluates abductions and makes available the measurements of the scapular elevations is described. Preliminary study and future works are also presented and discussed.
Keywords: Blender | Marker-less Motion capture system | Open source SDK | OpenPose | Shoulder rehabilitation
Abstract: The rehabilitation process of patients after spinal cord injury (SCI) is usually based on subjective visual assessment by medical staff of rehabilitation centers. During the process, the medical personnel train patients to manage wheelchair and they learn how to use their sensible body parts in order to have a satisfactory life-style. Furthermore, physiotherapists and physicians have to control patients to prevent wrong postures that could cause further disorders. This paper describes how a low-cost marker-less motion capture system can be exploited to create an objective assessment procedure. Three Microsoft Kinect v2 sensors have been used to track patients using their wheelchairs along a straight path. The three sensors are arranged to optimize the acquisition. Thanks to the collaboration with the medical staff, we identified the set of parameters necessary to monitor patients’ performance. An ad hoc application has been developed to provide the physicians with the right set of data easy readable to assess the patients along the rehabilitation process. The application has been tested involving twenty volunteers. Finally, results reached so far and further developments are summarized and discussed.
Keywords: Assessment of rehabilitation processes | Low-cost marker-less motion capture system | Microsoft Kinect v2 | Spinal cord injury
Abstract: This paper presents an approach for monitoring exercises of hand rehabilitation for past stroke patients. The developed solution uses a Leap Motion controller as hand-tracking device and embeds a supervised Machine Learning methodology. Support Vector Machine (SVM) is used in order to assess the correctness of a set of simple rehabilitation exercises performed with a single hand. The basic SVM model was extended with particular interest for defining feature vectors in a continues environment. The proposed method incorporated leap motion data, normalization of angles and gesture recognition. A software system was developed to provide patients with a set of exercise corrections and guidance for rehabilitation.
Keywords: Hand Rehabilitation | Leap Motion Controller | Stroke Patients | Support Vector Machines
Abstract: The effectiveness of custom-made prostheses or orthoses heavily depends on the experience and skills of the personnel involved in their production. For complex devices, such as lower limb prosthesis, a conventional manual approach affects the process at the point that the result is frequently not acceptable at the first trial. The paper presents a computer-aided environment, named socket modelling assistant2 (i.e., SMA 2) , to interactively design the socket of lower limb prosthesis by implementing a set of design rules extrapolated from the traditional development process. The new computer-aided environment has been implemented embracing a low-cost philosophy and using open source libraries to provide a solution affordable also by small orthopaedic laboratories. The system permits to modify and interact with the 3D model of residual limb to create the socket geometric model ready to be manufactured by means of additive manufacturing. SMA 2 embeds medical knowledge related to the device functioning, the conventional process and the way orthopaedic technicians work so that it can be much more reliable and repeatable compared to the conventional process, but still enough similar to it to be accepted by the involved personnel. In the paper, the new 3D design procedure is described in detail, from the acquisition of patient’s data to preliminary and customized modelling, and new geometric tools to perform context–related operations are shown. A case study is used to clarify the way the system works and to provide an example of the outcome.
Keywords: Additive manufacturing | Custom medical devices | Geometric modelling | Interactive design
Abstract: Rising reverse engineering applications require the use of 3D models based on polygonal meshes and a set of modeling operations to shape the final product. Usually, 3D modeling tools do not exploit existing software development kits for developing custom virtual applications. This approach can be very useful for reverse engineering process in the medical field. The paper describes the software development of local mesh modeling algorithms as an extension of the open source library VTK with the aim of shaping 3D triangulated meshes. Then, a case study has been considered to create virtual modeling tools supporting the design process of custom-fit products and, in particular, of lower limb prosthetic socket for amputees. The application has been tested to design a socket for a patient with an above knee amputation. Results reached so far provide a positive feedback on the quality of the designed process and outcome, mainly thanks to the use of the virtual tools based on the developed software modules for 3D mesh modeling.
Keywords: medical devices | Polygonal 3D modeling | prosthesis design | VTK
Abstract: Using a wheelchair can be a challenging task for people with reduced force and control of muscles of abdomen or lower back. Spinal cord injured (SCI) people are the majority of those who are spending most of the day on a wheelchair and a proper training and chair setup is mandatory to reach a good level of functionality and to avoid harms and side effects. In order to assess the complex motion of a person self-pushing a wheelchair, a motion capture (Mocap) system has been arranged and a group of SCI patients has been acquired in a hospital gym. The Mocap system uses three Microsoft Kinect RGB-D sensors and iPisoft to perform the recording of the 3D motion. The main goal of the research is to provide therapists with a quantitative method to define a preliminary configuration in an objective way once is given the user's medical conditions and his/her way of using the wheelchair. Working side by side with physiotherapists, the main parameters to be evaluated (e.g. pushing angles) have been identified and algorithms have been identified to automatically extract them from the 3D digital avatar model data coming from the Mocap system. The performance of the patients is then analyzed taking into account the wheelchair setup (e.g. position and inclination of the seat and of the back). The influence of geometric parameters on patients' motion is analyzed so that design guidelines for configuration can be found. The overall outcome is to maximize performance and minimize side effects and fatigue, providing users with a better experience on the wheelchair.
Abstract: The Natural User Interface (NUI), which permits a simple and consistent user’s interaction, represents a meaningful challenge for developing virtual/augmented reality applications. This paper presents a set of guidelines to design optimal NUI as well as a software framework, named FrameworkVR, which encapsulates the rules of presented guidelines. FrameworkVR allows developing NUI for VR/AR reality applications based on Oculus Rift, Leap Motions device and on the VTK open source library. An example of VR application for prosthesis design developed using FrameworkVR, is also described. Tests have been carried to validate the approach and the designed NUI and results reached so far are presented and discussed.
Abstract: A number of pathologies impact on the way a patient can either move or control the movements of the body. Traumas, articulation arthritis or generic orthopedic disease affect the way a person can walk or perform everyday movements; brain or spine issues can lead to a complete or partial impairment, affecting both muscular response and sensitivity. Each of these disorder shares the need of assessing patient’s condition while doing specific tests and exercises or accomplishing everyday life tasks. Moreover, also high-level sport activity may be worth using digital tools to acquire physical performances to be improved. The assessment can be done for several purpose, such as creating a custom physical rehabilitation plan, monitoring improvements or worsening over time, correcting wrong postures or bad habits and, in the sportive domain to optimize effectiveness of gestures or related energy consumption. The paper shows the use of low-cost motion capture techniques to acquire human motion, the transfer of motion data to a digital human model and the extraction of desired information according to each specific medical or sportive purpose. We adopted the well-known and widespread Mocap technology implemented by Microsoft Kinect devices and we used iPisoft tools to perform acquisition and the preliminary data elaboration on the virtual skeleton of the patient. The focus of the paper is on the working method that can be generalized to be adopted in any medical, rehabilitative or sportive condition in which the analysis of the motion is crucial. The acquisition scene can be optimized in terms of size and shape of the working volume and in the number and positioning of sensors. However, the most important and decisive phase consist in the knowledge acquisition and management. For each application and even for each single exercise or tasks a set of evaluation rules and thresholds must be extracted from literature or, more often, directly form experienced personnel. This operation is generally time consuming and require further iterations to be refined, but it is the core to generate an effective metric and to correctly assess patients and athletes performances. Once rules are defined, proper algorithms are defined and implemented to automatically extract only the relevant data in specific time frames to calculate performance indexes. At last, a report is generated according to final user requests and skills.
Abstract: The improvement and the massive diffusion of additive manufacturing (AM) techniques have fostered the research of design methods to exploit at best the feature introduced by these solutions. The whole design paradigm needs to be changed taking into account new manufacturing capabilities. AM is not only an innovative method of fabrication, but it requires a new way to design products. Traditional practices of mechanical design are changing to exploit all potential of AM, new parameters and geometries could be realized avoiding technologies constrains of molding or machine tooling. The concept of "manufacturing for design" increasingly acquires greater importance and this means we have the chance to focus almost entirely on product functionality. The possibility to confer inhomogeneous properties to objects provides an important design key. We will study behavior and structure according to desired functions for each object identifying three main aspects to vary: infill type, external topology and shape, and material composition. In this research work, we focus on fused deposition modeling (FDM) technology of three dimensional (3D) printing that easily allows to explore all previous conditions. We present a new way to conceive design process in order to confer variable properties to AM objects and some guidelines to control properties of deformation and elasticity using classic infills. The ultimate aim is to apply new design rules provided by AM in the prosthetic field of lower limb amputees. The socket of the prosthesis represents a deformable interface between the residual limb and the artificial leg that must be optimized according to geometry and loads distribution of patient. An application for a transfemoral patient will be discussed.
Abstract: This paper concerns the design and manufacture of medical devices, such as lower limb prosthesis, integrating low cost industrial technologies. In particular, it focuses the attention on the custom-fit component of a lower limb prosthesis, i.e., the socket, that is the interface with the residual limb. The considered process starts from the 3D reconstruction of patients’ limb and ends with the manufacture of the socket with a 3D printer using a multi-material approach. The process counts three steps: 3D modeling, testing (both experimental and numer-ical) and manufacturing. For each step adopted solutions and tools are described. Finally, conclusions are drawn mainly concerning the challenge of multi-material 3D printing of the socket.
Keywords: 3D printing | Lower limb prosthesis | Socket Modelling Assistant
Abstract: Additive Manufacturing (AM) is not only an innovative approach of fabrication but it fosters a new paradigm to design products. The possibility to confer inhomogeneous properties to the product provides an important design key. This paper concerns the design and manufacture of medical devices that require a high level of customization. We focus the attention on lower limb prosthesis and in particular on the prosthetic socket. The proposed method is centered on the virtual modeling of patient's residual limb and the virtual process is highly integrated and the data flow is as fluid as possible. Three main phases can be identified: design, validation and manufacture of the socket. Firstly, the technician uses the Socket Modeling Assistant (SMA) tool to design the socket shape. Then, a numerical simulation is run to check pressure distribution and validate the socket shape. Finally, a multi-material 3D printer is used to build the socket. Preliminary results are presented and conclusions are drawn concerning the challenge of multimaterial 3D printing of the socket.
Abstract: The way a person moves, either in a plain walk or performing a specific task, tells a huge quantity of information about his/her physical and, eventually, neurologic condition. A large part of a physiotherapist work of assessment is based on the qualitative evaluation, mainly visual, of a person's movements, in terms of balance, speed, control, force and other parameters. This research work aims at providing personnel involved in the rehab process with a quantitative method to assess the way movements are performed. A numerical measure of the performance, actually, allows easier and more precise assessment, eliminating bias due to subjectivity. To accomplish this goal two steps are required: 3D acquisition of the movement using a Motion Capture (Mocap) system, and analysis of collected data to extract or elaborate the final outcome in the form requested by the medical staff. The paper shows the way Mocap acquisition are performed and data are analyzed in the application with people having a complete spinal cord injury and using a wheelchair. The method has been tested with eight volunteers in the rehabilitation department of the Hospital Papa Giovanni XXIII in Bergamo, Italy.
Abstract: This paper presents an overview of main open source software, low-cost devices and related SDKs (Software Development Kits) that can be used to develop custom applications based on virtual and augmented reality. At present, the high modularity of the open source software for computer graphics allows developing custom applications with high quality for several research and industrial fields. To this end, we introduce a general-purpose software framework, which permits to manage the synchronization among the SDKs of different low-cost devices. Mentioned devices and software modules have been exploited to develop three applications in different fields.
Keywords: Low-cost devices | Open-source software | Virtual reality
Abstract: The paper explores the possibility of using low-cost motion capture technologies to automatically evaluate patient’s condition concerning his/her walking condition. Two different technologies, optical markerless and inertial, are used to track the gait to be adopted in a doctor’s office or at patient’s home. The data acquired are elaborated using commercial and in-house developed tools with the aim of creating, in a near future, a simple environment for medical staff and people non highly skilled in IC technology. The paper shows the feasibility of an automatic detection of a set of gait abnormalities affecting people having a lower limb prosthesis. This constitutes a robust support for orthopedic technicians work and foresees the use of such technology for larger surveys and early detection of gait deviations.
Keywords: Gait Analysis | Inertial sensors | Motion Capture | RGB-D sensors
Abstract: Digital Human Modelling (DHM) is becoming a simple way to study the ergonomic behaviour of devices interacting with the human body. In particular, innovative technologies per- mit to manage big amount of data coming from several IT devices in order to better understand the correlation be- tween technical aspects and human factors. In the medical field DHM can be exploited to combine in a unique applica- tion many data types coming from several inputs (e.g. 3D scan, motion capture). In this research work, the attention is focused on the design of lower limb prosthesis around the digital human model of the patient. We present an appli- cation, which allows visualizing pressure on patient's limb while evaluating his/her gait in a unique virtual knowledge- guided environment. Such application is conceived to be usable by non IT experts, and all information are directly visualized on the digital human model of the amputee. The first part of the paper describes the platform to design lower limb prosthesis with particular attention on the use of low- cost technologies. Then, the virtual gait analysis tool is described. Finally, tests and conclusion are discussed.
Keywords: Digital human modelling | Gait analysis | Lower limb prosthesis | Pressure mapping
Abstract: This paper presents a methodology and tools to improve the design of lower limb prosthesis through the measurement of pressure analysis at the interface residual limb-socket. The steps of the methodology and the design tools are presented using a case study focused on a transfemoral (amputation above knee) male amputee. The experimental setup based on F-Socket Tekscan pressure system is described as well the results of some static loading tests. Pressure data are visualized with a colour pressure map over the 3D model of the residual limb acquired using an optical low cost scanner, based on MS Kinect. Previous methodology is useful to evaluate a physical prototype; in order to improve also conceptual design, the Finite Element (FE) Analysis has been carried and results reached so far have been compared with experimental tests. Pressure distributions are comparable, even if some discrepancies have been highlighted due to sensors placements and implemented FE model. Future developments have been identified in order to improve the accuracy of the numerical simulations.
Abstract: The socket for lower limb prosthesis is the central element of artificial leg that needs to be optimize with the aim to increase comfort and reduce pain. Nowadays, the modeling of this part is completely manual and based on prosthetist skills. The key parameter determining if the socket is properly designed is the pressure distribution in the interface between the skin of residual limb and the internal surface of the socket. In this paper, we expose a method to measure this pressure thought resistive pressure sensors and we illustrate a case study of a transfemoral amputee patient. A visualization tool has been developed to dynamically show pressure data on the 3D model of the residual limb during topic moments of the gait by a color scale. Achieved results and future work will be discussed in the paper.
Keywords: Gait | Lower limb prosthesis | Pressure mapping
Abstract: This paper presents a method, which integrates digital human models (DHM) and virtual prototyping techniques to analyse ergonomic issues of devices to be used by workers. It is based on the comparison between the analysis of AS-IS and TO-BE scenarios with the aim of assessing design concepts, highlighting improvements or worsening and residual deficiencies to be faced. In particular, this paper refers to the case study of display units for groceries or supermarkets. Actually, workers who are in charge of filling the shelves perform highly repeated tasks, potentially dangerous for their health. The AS-IS and TO-BE analysis compares the actual practices with a new scenario in which workers are provided with lifting platforms to load the shelves. The method allows assessing several ergonomics parameters; in this study posture and fatigue are the most relevant. The results achieved with the simulations permitted to propose alternative solutions. Future works in this field concern the standardisation of domain dependant actions virtual human are asked to perform.
Keywords: Design validation | DHM | Digital human models | Display unit | Ergonomics analysis | Fatigue | Lifting AIDS | NIOSH | OWAS | Posture
Abstract: The paper shows a research activity aimed at integrating low cost industrial technologies in the design, test and man- ufacture of medical devices. This work focuses on lower limb prosthesis and in particular on the custom-fit compo- nent interacting with the residual limb, i.e. the socket. The process going from the 3D reconstruction of patients' limb to the manufacture of the socket by means of a 3D printer has been designed. Moreover, this must be as automatic as possible and should not require the presence of a design and simulation expert. This implied a deep involvement of physicians and orthopaedic technicians in order to embed rules and procedures in the system. The process is divided in three steps: design, test and manufacture. For each step some details are shown and at last some conclusions are drawn mainly concerning the challenge of multi-material 3D printing of the socket.
Keywords: 3D printing | Lower Limb Pros-thesis | Socket Modelling Assistant
Abstract: The diffusion of depth sensors to sense people and objects constitutes an outstanding opportunity in those fields in which the benefits of optical marker-less solutions for scanning or tracking are requested. This paper shows how two different applications based on MS Kinect device can be accomplished in the domain of lower limb prosthesis design and test. The first one refers to the use of a depth camera as a three-dimensional scanner to acquire the geometry of residual limbs or of custom-fit components. The second application is related to the motion capture of patients' gait with the prosthesis. In both cases, the technology resulted to be better than many traditional ones mainly for its limited invasivity, interesting performance, portability and low cost.
Keywords: 3D scanner | Digital human modelling | Lower limb prosthesis | Motion capture | RGB-D cameras
Abstract: The diffusion of depth sensors to sense people and objects constitutes an outstanding opportunity in those fields in which the benefits of optical marker-less solutions for scanning or tracking are requested. This paper shows how two different applications based on MS Kinect device can be accomplished in the domain of lower limb prosthesis design and test. The first one refers to the use of a depth camera as a three-dimensional scanner to acquire the geometry of residual limbs or of custom-fit components. The second application is related to the motion capture of patients' gait with the prosthesis. In both cases, the technology resulted to be better than many traditional ones mainly for its limited invasivity, interesting performance, portability and low cost.
Keywords: 3D scanner | Digital human modelling | Lower limb prosthesis | Motion capture | RGB-D cameras
Abstract: The present paper describes the research done to empirically validate the use of RGB-D cameras for orthopedic rehabilitation purposes. In order to assess the outcome of optical sensors a set of new generation inertial sensors have been adopted as well. Both kind of sensors have been used to track the same scene simultaneously in order to have comparable results. The aim of the work is provide evidence of performances of the newly introduced sensors (optical and inertial) and to automate acquisition and data elaboration in the medical field. The extraction of the only meaningful data from a gait, for instance, gives the change to perform an automatic preliminary analysis on normal people as well as on patients with known pathologies or disorders. In particular, this could allow determining without human intervention any standard disorders, according to literature classifications, eventually affecting the gait. The automatic procedure from acquisition to diagnosis constitutes a challenging topic of research and a success in terms of reliability, usability and physiological acceptance by technicians would radically impact medical practices in orthopedic rehabilitation centers.
Abstract: The paper concerns the use of integrated methodologies and tools to perform innovative human centered development of products. Digital simulation of ergonomics by means of DHM is shown together with advanced tools for design, taking into account Knowledge-based systems, Design Automation and design of highly customized goods. Two different applications of the proposed approach are described, the first refers to an industrial product, the second to the medical domain. Both applications, even if belonging to completely different fields benefit from putting the human at the center of the developing paradigm from the very first step of product development. Some results and discussion highlight benefits and limitation of the approach and of the adopted tools.
Keywords: Design Automation | Digital human modelling | Ergonomics | Human centered design | Knowledge-based systems | Lower limb prosthesis
Abstract: This paper presents an approach to automate and integrate numerical simulations within knowledge-based engineering applications to improve the use of simulation tools, especially in small and medium enterprises. Main discussed issues concern: (a) the importance of the CAD model as an input of the process, (b) data migration from CAD to CAE tools, (c) model characterisation, (d) effects of parameters variations, (e) simulation steps, and (f) results evaluation. In addition, formalisation and representation of rules and procedures to automate the design process, in particular the simulation tasks, are presented. Two case studies are described to explain and verify the approach. The first case concerns the design process of centrifugal industrial fans, during which simulation tools are used to verify the correct sizing of impeller blades. The second one is related to a non-industrial process; actually, it regards a medical device, and more precisely lower limb prosthesis. Finally, main results are discussed.
Keywords: Embedded simulations | Industrial fan | KBE | Knowledge-based engineering | Simulation rules | Socket design
Abstract: Motion capture of the human body has being performed for decades with a growing number of technologies, aims and application fields; but only recent optical markerless technologies based on silhouette recognition and depth sensors which have been developed for videogames control interface have brought motion capture to a broad diffusion. Actually, nowadays there are low cost hardware and software suitable for a wide range of applications that may vary from entertainment domain (e.g., videogames, virtual characters in movies) to the biomechanical and biomedical domain (e.g., gait analysis or orthopedic rehabilitation) and to a huge number of industrial sectors. In this quick evolving scenario it is hard to tell which technology is the most suitable for any desired goal. The aim of the paper is to answer to this issue by presenting a benchmark analysis that compares RGB and RGB-D technologies used to track performing people in a variety of conditions. In order to contrast the solutions, several different tasks have been selected, simultaneously captured and post-processed exactly in the same way. The test campaign has been designed to evaluate pros and cons according to the most important feature of a motion capture technology, such as volume of acquisition, accuracy of joint position and tracking of fast movements. Actors were asked to perform a number of tasks, among which free movements of arms, legs and full body, gait, and tasks performed interacting with a machine. The number of sensors around the scene and their disposition have been considered as well. We used Sony PS Eye cameras and Microsoft Kinect sensors as hardware solutions and iPisoft for data elaboration. The gathered results are organized, compared and discussed stressing performances and limitations of any combination and, at last, we proposed the best candidate technology for some key applications.
Keywords: Benchmark | Depth cameras | Digital Human Models | Motion capture | RGB | RGB-D
Abstract: This paper presents an automatic simulation procedure to study the stump-socket interaction that has been embedded within a software platform specifically developed to design lower limb prosthesis. In particular, it investigates and compares the results obtained by means of FE tools with the experimental data acquired with pressure transducers. A transfemoral (amputation above knee) male amputee has been considered as case study. Numerical simulations have been carried out considering different techniques to acquire the residuum geometry and different socket models. In details, two residuum geometric models were reconstructed starting from MRI images and from 3D scanning to investigate how acquisition techniques influence the final results. Two socket geometric models were taken into account. The first was the patient's real socket, acquired by 3D scanning; the second one has been modeled using a dedicated CAD system, named Socket Modeling Assistant. The patient's real socket has been also used to perform the experimental pressure measurements. The experimental data have been acquired by means of the Tekscan F-socket system. Results reached so far allowed identifying main criticalities and future developments to improve the accuracy of the numerical results and make available a full-automated simulation procedure.
Abstract: This paper refers to the integration of simulations tools to assess the design of prosthetic devices. We address issues arising when the prosthesis needs to be virtually tested, i.e., the gait of the virtual patient wearing the prosthesis. Therefore, we integrate two different simulation tools: the first one to study the interaction between socket and residual limb during the gait and the second one to analyze the patient's gait deviations. Combining these numerical analyses, it is possible to investigate the causes of gait deviations and suggest remedies, both related to the prosthesis setup and the socket modeling. To prove the validity of the approach, we implemented a Finite Element Analysis model to analysis the stump-socket contact and we assembled a low cost Motion Capture system to acquire and elaborate patient gait. Preliminary results and remarks conclude the paper.
Abstract: This paper refers to the context of virtual ergonomics and specifically addresses a case study of the commercial refrigeration industry. The aim is to develop a computer-aided platform to analyse end-users' postures and movements and ergonomically validate the design of device a man or woman may deal with. This paper describes the integrated use of human modeling and motion capture (Mocap) systems to perform ergonomic analysis relying exactly on real movements. Two optical Mocap systems, both low cost and markerless, have been considered: one based on six Sony Eye webcams and another one on two Microsoft Kinect sensors. Analogously, two human modeling tools have been adopted: Jack, specifically targeted for ergonomics and integrated with Microsoft Kinect, and LifeMod, a biomechanical simulation package. The proposed virtual ergonomics solutions have been experimented considering the case study of vertical refrigerator display units. © 2013 Springer-Verlag.
Keywords: commercial refrigeration | Digital human modeling | Mocap | Virtual ergonomics
Abstract: This paper presents a methodological approach to analyze ergonomic issues of equipment specifically designed to load refrigerated display units. The methodology is based on the integrated use of virtual humans and prototyping techniques and on the comparison between the analysis of AS-IS product and TO-BE design concepts to highlight improvements or worsening of the new design and eventual residual deficiencies. In particular, Digital Human Models have been adopted to evaluate different technical solutions for pick and place operations of food items on the display unit shelves according to the specific needs of supermarket operators and to ensure health and hygienic conditions. We first present the state of the art of digital human models and the referring standards for workplace regulations in terms of postures and fatigue. The adopted methodology is described including chosen virtual humans, refrigerated units and handled products. Then, the application of the methodology is described as well as the ergonomics tests and results obtained for the AS-IS and TO-BE solutions. Finally, discussion of results and conclusions are reported. © 2013 CAD Solutions, LLC.
Keywords: Ergonomic design | Refrigerated display unit | Virtual humans
Abstract: Maintenance is one of the key drivers for future company success, due to the fact that these kinds of operations are strictly related to human labor cost, an expensive factor for western states. Furthermore, in the last decades, norms and laws on safety and ergonomics of the work place have taken importance among industrialized countries. Design for Maintenance is a design methodology that since early stages of product life cycle outlines needs and necessities of maintainers, in order to reduces time and cost; decreasing the complexity and the difficulties of these procedures and achieving a higher standard of workers' health. In order to reach this goal, Digital Human Models (DHM) have been used to simulate assembly and maintenance processes. Virtual ergonomic analysis performed with a human model allows evaluating visibility, reachability and postures, stress and fatigue. The lack of methods supporting virtual ergonomics simulation has been addressed by proposing a systematic approach based on a step-by-step procedure and proper tools. The said procedure was applied on a case study and results on the method and on its application are shown. © 2013 Copyright CAD Solutions, LLC.
Keywords: design for maintenance | digital human modeling | ergonomics
Abstract: Lower limb prostheses for above or below knee amputees are still designed and produced almost completely in a manual way, deeply relying on the experience and manual skills of orthopaedic technicians. This paper presents the main features characterising the prototype of a virtual environment developed to assist the technicians designing and testing the prosthesis. To reach the ambitious goal of replacing the manual process with a complete virtual one several issues have been considered and addressed: the capture and formalisation of process knowledge of orthopaedic technicians, the acquisition of patient's information and digital data, the development of an integrated solution to design and test standard and custom-fit components and the simulation of the gait of a virtual human wearing the virtual prosthesis. The architecture of the prosthesis design platform as well as the modelling and simulation tools are described. Finally, the experimentation phase and related results are presented and discussed. © 2013 Copyright Taylor and Francis Group, LLC.
Keywords: design environment | digital human modelling | lower limb | prosthesis
Abstract: This paper presents a computer-Aided environment to analyze postures and movements in order to ergonomically validate the design of potentially any device a man or woman may have to deal with. The proposed environment integrates virtual prototyping techniques with Digital Human Modeling and Motion Capture techniques to determine fatigue, stress and risk for workersâTM health. We considered a vertical refrigerated display unit as case study to analyze the interaction of supermarket staff filling the shelves with goods with the main goal determining the suitability of operatorsâTM working condition and, eventually, providing a feedback to the design step. The paper, after a brief description of the state of the art of the Motion Capture system and Digital Human Modeling, presents the architecture of the integrated environment developed and the working paradigm. At last preliminary results of the experimentation as well benefits and the limits of the outcomes achieved so far in the automation of ergonomics in machines design are presented. Copyright © 2012 by ASME.
Abstract: Modular lower limb prosthesis is composed by custom-fit parts, such as the socket containing the residual limb, and standard components available on market, such as knee or foot. For both custom and standard parts the support offered by existing design tools is not efficient or integrated enough and, as a result, most prosthetists do not use computer-aided tools and still rely only on their personal expertise. This paper presents an approach to design and configure complete lower limb prosthesis for transfemoral and transtibial amputees, using patient's digital data (e.g., residual limb model acquired by MRI) and specification sheets of components. The ultimate goal is to realise a virtual laboratory where the technicians can design lower limb prosthesis guided step by step by the system. We have identified key patient's characteristics guiding the prosthetist during the four main steps of the production process: acquiring patient's data, socket modelling, standard components selection and prosthesis assembly and check. The developed innovative framework integrates different tools to guide the technicians during each design task providing specific knowledge and rules. Thus, it allows a quicker and easier definition of the virtual prosthesis, on which virtual test could be performed (e.g., pressure distribution on residual limb, gait evaluation) in order to be able to realize the definitive prosthesis at the first attempt. The results have been evaluated and validated with the technical staff of a certified orthopaedic laboratory. © 2011 by ASME.
Abstract: In this paper, we present a methodology and a working paradigm, based on TRIZ theory, specifically conceived for SMEs that are not able to face the problem of intellectual property management (IPM) in an autonomous way. As a first step, we introduce the competences and possible company structure to manage and protect intellectual property (IP) by means of patents and trademarks; then we describe the methodologies and the tools, which can be used for IPM, such as those derived from TRIZ. Finally, we describe a case study which refers to a typical example of know-how transfer from a technological leading sector to the large production of consumable products showing the use of considered TRIZ tools. © 2011 Inderscience Enterprises Ltd.
Keywords: Intellectual property management | IPM | Patents | SMEs | TRIZ
Abstract: The paper discloses a method for conceptual design oriented to generation of new product concepts based on in-depth knowledge and experience of systematic innovation methods and tools, but that does not require specific advanced skills to be performed. The method has been freely inspired by TRIZ Laws of Technical System Evolution (LTSE). It is structured as a sequence of practical guidelines and operative rules that guide designers through an unconventional paradigm leading to breakthrough ideas and new solutions. It has been checked through a set of test cases offered by local companies and performed by engineering students. Copyright © 2011 Inderscience Enterprises Ltd.
Keywords: Creativity | Design guidelines | Laws of technical system evolution | Product development | TRIZ
Abstract: This paper discloses an innovative step by step method based on TRIZ tools used according to the general approach suggested by FMEA. The aim of the proposed method consists in building an improved risk management model for design and to enhance the capability of anticipating problems and technical solutions to reduce failure occurrence. The method adopts tools used to model the system, such as functionality, Su-Fields models, resource evaluation and tools dedicated to problem solving such as standard solutions. The resulting method allows a better definition of the system decomposition and functioning and provides a sharp definition of the events and failures potentially occurring into the system, which is not provided by standard FMEA. Moreover, the high importance given to resources since the beginning of the method is extremely effective for understanding system evolution and to generate resource-based solution to problems dealing with product risk. The overall method has been developed so that technicians are not supposed to have a high level expertise in TRIZ tools. In order to evaluate the method it was tested with students with basic level TRIZ education and some application with industrial case studies were performed. © 2011 Published by Elsevier Ltd.
Keywords: ENV model | FMEA | Risk management | Su-Field | TRIZ
Abstract: Sustainability is one of the most recent theme designers have to deal with and sustainability parameters are quickly gaining the top of the list of the requirements any product has to fulfil. Due to standards, legal regulation and customer growing awareness of environmental issues, engineers cannot avoid turning their everyday activities from design to eco-design. By the way, a significant drop of environmental impact of products cannot be achieved by simply adding a 'green' constraint to the already overpopulated list of design constraints. To answer to this issue a plurality of methods are available helping the designer (or pretending to) to assess product lifecycle or to provide suggestions on how to innovate the product or process according to sustainable goals. Within this context, the present work describes a way of using TRIZ concepts and tools in order to both assess and innovate a technical system so that some practical activities to ensure sustainable results can be easily embodied into everyday design practice. The main novelty on the operative level consists of an original method based on a set of Guidelines derived from Laws of Technical System Evolution (LTSE) in order to assess the value of existing solution (e.g. using Resources and Functionality as a metric of evaluation), to understand the most promising directions of improvement and to improve said solution also according to sustainability requirements. The paper will show the way Guidelines are applied with practical examples and an industrial case study will be presented and discussed. © 2011 Published by Elsevier Ltd.
Keywords: Eco-design | Eco-guidelines | LTSE | Resources
Abstract: This work relates to a methodology for effectively modeling an Action and Problem System and documenting a path built by means of patent databases. The aim of this work is to provide an improved method and operative tool for a quick and reliable patents investigation driven by Boolean algorithms. The method has been tested with several projects for companies of different industrial areas. Moreover in the last months the method has been used in case studies by students from the University of Bergamo with good results after a very few hours of training. Two specific case studies will be discussed in this paper in order to clarify the operative value of said method and to show the results obtained in terms of solutions found and of efforts requested. © 2011 Published by Elsevier Ltd.
Keywords: Kinetic model | Patent databases | Patent investigation | Potential model
Abstract: This research work regards the development of a new roadmap for complex products design based on an improved modular approach. The goal is to refine an existing method affected by some drawbacks into a to new product development paradigm, with the aim of reducing design times, mistakes and subjectivity. The best results came from integrating a set of diverse methodologies for product design and systematic innovation. The proposed design paradigm is based on an improved Modular-TRIZ-DSM approach, and the results obtained, in terms of modules definition and interfaces, have been evaluated. The most important results concern a better repeatability of design results and the capability to forecast technical evolution of a specific product family. After a short description of the methodologies of interest, the roadmap is described focusing on the differences from the traditional method. Copyright © 2008 by ASME.
Abstract: The design and implementation of a PLM solution in a cross-company environment is a complex and labour intensive operation, which is often coupled with a Business Process Re-engineering (BPR) project to better deploy technologies as well as methodologies and to target the system implementation on the real company needs. Enterprise Modelling (EM) languages are typically used to collect and share process knowledge among the BPR participants. Plenty of techniques are actually available at this scope and it is not always easy to understand how to select and use them in the different steps of re-engineering. The main purpose of this paper is to perform a qualitative analysis of three well known EM languages (IDEF, UML and ARIS) and to propose a new methodology, based on their integrated use, supporting BPR efforts in the Product Development domain. © 2009 Elsevier B.V. All rights reserved.
Keywords: ARIS | Business Process Re-engineering | Enterprise Modelling | IDEF | UML
Abstract: This research work regards the development of a new roadmap for complex products design based on an improved modular approach. The goal is to refine an existing method affected by some drawbacks into a to new product development paradigm, with the aim of reducing design times, mistakes and subjectivity. The best results came from integrating a set of diverse methodologies for product design and systematic innovation. The proposed design paradigm is based on an improved Modular-TRIZ-DSM approach, and the results obtained, in terms of modules definition and interfaces, have been evaluated. The most important results concern a better repeatability of design results and the capability to forecast technical evolution of a specific product family. After a short description of the methodologies of interest, the roadmap is described focusing on the differences from the traditional method. Copyright © 2008 by ASME.
Abstract: Among TRIZ users the importance given to patent resources is far behind the mere protection of R&D results. Patents represent a starting point for new inventions and a huge resource for collecting information on the way contradictions have been solved and in which different field such solutions may be adopted. Moreover the worldwide patent database contains information about the technology evolution that can be extracted so that the level of maturity of a product or process can be evaluated towards TRIZ laws of technical evolution. The contribution of this paper is to provide a step by step procedure, partially automatic, to perform TRIZ oriented patent search. The procedure, while determining the level of innovation of patents, allows defining a sharp set of patents responding to a structured query. The procedure has been applied to several case studies of different fields (e.g. mechanical, medical, and electronics) and a significant example referring to X-rays technology is shown in the paper. © 2008 International Federation for Information Processing.
Keywords: Level of inventiveness | Patent clustering | Patent investigation | TRIZ
Abstract: This paper presents an approach to evaluate product ergonomics using virtual humans. This work has been carried out to demonstrate that virtual humans are an important tool to improve virtual prototyping functionalities and, above all, to increase ergonomics and safety of products. A test methodology has been defined and several simulations have been made, varying anthropometry and workplace conditions. Two case studies that can demonstrate the validity of the approach are described. The first concerns instruments of a car for which the geometric model of the interior and a commercial virtual human have been used. The second case study concerns the external visibility of a farm tractor that can be equipped with different tools to accomplish to various tasks (e.g. harvesting and fruit picking). The results obtained are images that represent what the virtual human sees and permit to compare and validate different design solutions.
Keywords: Ergonomics | Internal and external visibility | Virtual manikin
Abstract: This paper describes the results of an experience carried out in the field of systematic innovation. Its main goal has been to verify the validity of evolutionary laws introduced by TRIZ theory applying them to a complex industrial product. The product considered is a washing machine and particular attention has been focused on two sub-systems, the tub and the soap dispenser. The paper, first, describes the patent search activity carried out for both the whole washing machine and the specific subsystems; then their evolutions have been single out and compared with the evolution patterns coming from the formulation proposed by Savransky.
Keywords: Intellectual property management | Trend of evolutions | TRIZ
Abstract: This paper presents methodology and guidelines about the use of process modeling languages to support BPR activities in relation with Product Development process. The methodology is based on the complementary adoption of different modeling techniques such as IDEF, UML and ARIS. Starting from the analysis of different models, we have selected and associated the most appropriate modeling suite to each phase of the re-engineering process. At this purpose, diagrams coming from IDEF, UML and ARIS families have been compared with respect to following issues: Degree of formality, completeness, simplicity vs. detail, capability to describe "business goal" and support to costing operations. © 2006 International Federation for Information Processing.
Keywords: ARIS | Business process re-engineering | IDEF | Process modeling | Product development process | UML