Mihai Dragusanu, Z. Iqbal, D. Prattichizzo, M. Malvezzi
Nowadays, the rehabilitation process can significantly increase the efficacy exploiting the potentialities of robot-mediated therapies. Robot rehabilitation is an emerging and promising topic that incorporates robotics with neuroscience and rehabilitation to define new methods for supporting patients with neurological diseases. In this paper we present the design of an innovative exoskeleton for hand finger flexion/extension motion rehabilitation and training. It is designed to be modular, wearable, and easy to control and manage. It can be used by the patient in collaboration with the therapist or autonomously. The paper introduces the main steps of device design and development and presents and compare three different solutions.
{"title":"Design of a Modular Hand Exoskeleton for Rehabilitation and Training","authors":"Mihai Dragusanu, Z. Iqbal, D. Prattichizzo, M. Malvezzi","doi":"10.1115/imece2021-70343","DOIUrl":"https://doi.org/10.1115/imece2021-70343","url":null,"abstract":"\u0000 Nowadays, the rehabilitation process can significantly increase the efficacy exploiting the potentialities of robot-mediated therapies. Robot rehabilitation is an emerging and promising topic that incorporates robotics with neuroscience and rehabilitation to define new methods for supporting patients with neurological diseases. In this paper we present the design of an innovative exoskeleton for hand finger flexion/extension motion rehabilitation and training. It is designed to be modular, wearable, and easy to control and manage. It can be used by the patient in collaboration with the therapist or autonomously. The paper introduces the main steps of device design and development and presents and compare three different solutions.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122181395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Much of the population have mobility disabilities. A market analysis highlighted the lack of a low-cost mobility solution that could provide terrain versatility, torso support, combined wheelchair functionality, and sit-to-stand assistance. Furthermore, the use of common, readily available parts for device life maintenance is advantageous for the intended use in rural areas. This study describes a design for a mobility solution. A simulation and analysis are performed using multi-body software to determine the interaction between the vehicle on different types of obstacles, as well as determine forces in the riskiest parts of the design for connection strength analysis. To complete this simulation, several determinations had to be obtained to use proper constraints for the system, such as the force the caregiver would push with and the damping of the tires. A physical test is performed to find the average force required to push a wheelchair and patient over outdoor, bumpy terrain. This study makes multiple suggestions for mobility device design that contrast with trending design priorities in the medical device industry and provides evidence for these recommendations. The results of the created simulations are used to make design choices regarding wheel configuration and size.
{"title":"Simulation of a Terrain Versatile Walker-Wheelchair With Torso Support","authors":"James Manzer, Gabriel Simon Sosa, D. Piovesan","doi":"10.1115/imece2021-73245","DOIUrl":"https://doi.org/10.1115/imece2021-73245","url":null,"abstract":"\u0000 Much of the population have mobility disabilities. A market analysis highlighted the lack of a low-cost mobility solution that could provide terrain versatility, torso support, combined wheelchair functionality, and sit-to-stand assistance. Furthermore, the use of common, readily available parts for device life maintenance is advantageous for the intended use in rural areas.\u0000 This study describes a design for a mobility solution. A simulation and analysis are performed using multi-body software to determine the interaction between the vehicle on different types of obstacles, as well as determine forces in the riskiest parts of the design for connection strength analysis.\u0000 To complete this simulation, several determinations had to be obtained to use proper constraints for the system, such as the force the caregiver would push with and the damping of the tires. A physical test is performed to find the average force required to push a wheelchair and patient over outdoor, bumpy terrain. This study makes multiple suggestions for mobility device design that contrast with trending design priorities in the medical device industry and provides evidence for these recommendations. The results of the created simulations are used to make design choices regarding wheel configuration and size.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124312555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Micro-, and milli-scale robots have emerged as next generation of intelligent technology for minimally invasive diagnosis and treatment. Recent minimally invasive interventions call for robots that work as tiny “surgeons” or drug delivery “vehicles” to achieve inner body diagnostic, surgical, and therapeutic practices, without any trauma or discomfort. Most traditional medical robots are large, and lack effective locomotion design, which prevent them from entering small entrances and moving smoothly in small working areas, such as long and narrow passages. Presented in this paper is a design of an innovative milli-scale deployable tensegrity microrobot for minimally invasive interventions. The robot is made of a deployable tensegrity structure integrated by self-stress. A folded size of the robot is small for easily entering a desired working area with a small entrance. When deployed, the tensegrity body of the robot displays lightweight and high stiffness to sustain loads and prevent damages when burrowing through tightly packed tissues or high-pressure environments. Locomotion of the tensegrity microrobot is designed to mimic a crawling motion of an earthworm, which grants the robot an ability to move well through small working areas. The robot is also an untethered agent. Morphing for deployment and locomotion of the robot is actuated by magnetic forces generated by its active members that serve as electromagnetic coils.
{"title":"A Deployable Tensegrity Microrobot for Minimally Invasive Interventions","authors":"S. Yuan, Wuming Jing, Hao Jiang","doi":"10.1115/imece2021-67009","DOIUrl":"https://doi.org/10.1115/imece2021-67009","url":null,"abstract":"\u0000 Micro-, and milli-scale robots have emerged as next generation of intelligent technology for minimally invasive diagnosis and treatment. Recent minimally invasive interventions call for robots that work as tiny “surgeons” or drug delivery “vehicles” to achieve inner body diagnostic, surgical, and therapeutic practices, without any trauma or discomfort. Most traditional medical robots are large, and lack effective locomotion design, which prevent them from entering small entrances and moving smoothly in small working areas, such as long and narrow passages. Presented in this paper is a design of an innovative milli-scale deployable tensegrity microrobot for minimally invasive interventions. The robot is made of a deployable tensegrity structure integrated by self-stress. A folded size of the robot is small for easily entering a desired working area with a small entrance. When deployed, the tensegrity body of the robot displays lightweight and high stiffness to sustain loads and prevent damages when burrowing through tightly packed tissues or high-pressure environments. Locomotion of the tensegrity microrobot is designed to mimic a crawling motion of an earthworm, which grants the robot an ability to move well through small working areas. The robot is also an untethered agent. Morphing for deployment and locomotion of the robot is actuated by magnetic forces generated by its active members that serve as electromagnetic coils.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117226416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brandon A. Brown, R. Daniel, V. Chancey, Tyler F. Rooks
Environmental sensors (ES) are a proposed way to identify potentially concussive events using Rigid Body Kinematics (RBK) to get motion at the head CG. This study systematically investigated the extent that errors in RBK assumptions including sensor orientation (SO), head CG position (HCGP), and exposure severity contribute to errors in sensor readings of predicted peak resultant linear acceleration (PRLA) at the head CG. Simulated sensor readings were defined by idealized representations of head motion [extension, lateral bending and axial rotation] using a half sine pulse for linear and angular acceleration. Peak magnitudes of linear acceleration ranged from 12.5 to 100 Gs and peak magnitudes of angular acceleration ranged from 1250 to 10000 rad/s/s. Durations of linear and angular accelerations ranged between 5 and 30 ms. Simulated HCGP variations ranged from −10% to 10% radius of the head (assumed to be a sphere) in each direction and SO variations ranged from −20 to 20 degrees about each axis. True head CG response was calculated using zero error for SO and HCGP. Mean (+/− standard deviation) of calculated errors for maximum percent error (MaxPE) of a given head exposure was 30.3% (+/−9.71). 50% and 38% of all simulated exposures had MaxPE associated with maximum SO and HCGP offset, respectively. MaxPE was likely due to user error, ES form factor, and anthropometric variation.
{"title":"Parametric Evaluation of Head Center of Gravity Acceleration Error From Rigid Body Kinematics Assumptions Used in Environmental Sensors","authors":"Brandon A. Brown, R. Daniel, V. Chancey, Tyler F. Rooks","doi":"10.1115/imece2021-69334","DOIUrl":"https://doi.org/10.1115/imece2021-69334","url":null,"abstract":"\u0000 Environmental sensors (ES) are a proposed way to identify potentially concussive events using Rigid Body Kinematics (RBK) to get motion at the head CG. This study systematically investigated the extent that errors in RBK assumptions including sensor orientation (SO), head CG position (HCGP), and exposure severity contribute to errors in sensor readings of predicted peak resultant linear acceleration (PRLA) at the head CG. Simulated sensor readings were defined by idealized representations of head motion [extension, lateral bending and axial rotation] using a half sine pulse for linear and angular acceleration. Peak magnitudes of linear acceleration ranged from 12.5 to 100 Gs and peak magnitudes of angular acceleration ranged from 1250 to 10000 rad/s/s. Durations of linear and angular accelerations ranged between 5 and 30 ms. Simulated HCGP variations ranged from −10% to 10% radius of the head (assumed to be a sphere) in each direction and SO variations ranged from −20 to 20 degrees about each axis. True head CG response was calculated using zero error for SO and HCGP. Mean (+/− standard deviation) of calculated errors for maximum percent error (MaxPE) of a given head exposure was 30.3% (+/−9.71). 50% and 38% of all simulated exposures had MaxPE associated with maximum SO and HCGP offset, respectively. MaxPE was likely due to user error, ES form factor, and anthropometric variation.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126382997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As human beings age, their bodies tend to deteriorate. It is the task of an engineer to counteract this natural process to ensure that humans can have a high quality of life for as long as possible. A condition that affects a wide range of people life is a discomfort and pain in the knee. This is most often caused by osteoarthritis, which occurs when the cartilage in the knee deteriorates causing the bones to rub against each other creating extreme discomfort. In this study, the attempt is to design an inexpensive and practical prosthesis to maintain and preserve the patient’s anterior cruciate ligament. The other design goals of this prosthesis are to be manufacturable and applicable by surgeons. Further, the finite element analysis has been conducted to assure the designed prosthesis can withstand the physiological loads applied on knees during daily activities.
{"title":"Design of Knee Prosthesis to Sustain ACL/PCL Ligaments and Alleviate Osteoarthritis","authors":"Peyman Honarmandi, Erwan Malki","doi":"10.1115/imece2021-72166","DOIUrl":"https://doi.org/10.1115/imece2021-72166","url":null,"abstract":"\u0000 As human beings age, their bodies tend to deteriorate. It is the task of an engineer to counteract this natural process to ensure that humans can have a high quality of life for as long as possible. A condition that affects a wide range of people life is a discomfort and pain in the knee. This is most often caused by osteoarthritis, which occurs when the cartilage in the knee deteriorates causing the bones to rub against each other creating extreme discomfort. In this study, the attempt is to design an inexpensive and practical prosthesis to maintain and preserve the patient’s anterior cruciate ligament. The other design goals of this prosthesis are to be manufacturable and applicable by surgeons. Further, the finite element analysis has been conducted to assure the designed prosthesis can withstand the physiological loads applied on knees during daily activities.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115741335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, an investigation into the dynamics flow behaviour of a humidifier unit is carried out using the numerical simulation method. The Computational Aeroacoustics (CAA) with a hybrid approach is conducted in the ANSYS software environment. The CFD simulations were used to investigate the internal flow behaviours of the humification fluid model. The predicted results have shown the internal flow characteristics combined with scatters, circulations, and separation behaviours. These behaviours are due to the installation of a baffle unit inside the humification unit. Turbulent and pressure fluctuations were used to predict the noise level generated within the system. The predicted results are compared with the experimental results for validation. The comparison shows the predicted results agreed with the experimental result with some differences in frequency analysis. In summary, the numerical model was developed for the CPAP humidifier unit to study the internal flow behaviours and the potential noise source location. The predicted results have explained and identified some locations of interest. These findings were used as guidelines to optimise and further develop to improve the future product. It also concludes that the CAA approach can be considered as a potential cost-effective tool in the early product development process for a better product design.
{"title":"Computational Modeling and Analysis of Turbulent Flows in the Humidification Unit of the Continuous Positive Airways Pressure Device","authors":"T. Vuong, A. Al-Jumaily","doi":"10.1115/imece2021-68573","DOIUrl":"https://doi.org/10.1115/imece2021-68573","url":null,"abstract":"\u0000 In this paper, an investigation into the dynamics flow behaviour of a humidifier unit is carried out using the numerical simulation method. The Computational Aeroacoustics (CAA) with a hybrid approach is conducted in the ANSYS software environment.\u0000 The CFD simulations were used to investigate the internal flow behaviours of the humification fluid model. The predicted results have shown the internal flow characteristics combined with scatters, circulations, and separation behaviours. These behaviours are due to the installation of a baffle unit inside the humification unit. Turbulent and pressure fluctuations were used to predict the noise level generated within the system. The predicted results are compared with the experimental results for validation. The comparison shows the predicted results agreed with the experimental result with some differences in frequency analysis.\u0000 In summary, the numerical model was developed for the CPAP humidifier unit to study the internal flow behaviours and the potential noise source location. The predicted results have explained and identified some locations of interest. These findings were used as guidelines to optimise and further develop to improve the future product. It also concludes that the CAA approach can be considered as a potential cost-effective tool in the early product development process for a better product design.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129073594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carotid artery is the major blood vessel which carries oxygenated blood to the brain and the face. Atherosclerosis is a major arterial disease characterized by a progressive contraction of the blood vessel. It occurs due to the deposition of cholesterol and lipids beneath the internal layer of the artery which is called stenosis. Carotid artery stenosis causes serious implications which considered one of the leading causes of morbidity and mortality in most countries. The existence of stenosis had a significant effect on the blood flow dynamic factors. Adding the arterial wall response through the wall elasticity will achieve more accurate and realistic flow characteristics. In this study, the arterial wall elasticity through two-way Fluid-Structure Interaction (FSI) was considered to the developed model to calculate the blood flow dynamics. Moreover, blood dynamic factors will be used to investigate the flow characteristics with rigid and elastic arterial wall and temporal blood responses. To estimate the blood dynamic factors, a three-dimensional reconstructed patient-specific carotid artery geometry with realistic boundary conditions is considered. Hence, a three-dimensional comprehensive model including the non-Newtonian Carreau blood flow viscosity model under pulsatile flow conditions is developed. The two-way FSI procedure was performed by applying an arbitrary Lagrangian-Eulerian (ALE) formulation to calculate the arterial response. Results indicated that using FSI has a crucial role in investigating the blood flow dynamic factors which resulted in low shear stress, pressure gradient, and velocity distribution comparing to the rigid arterial wall response. The efficient use of Computational Fluid Dynamics (CFD) has the potential to shed light on the assessment of the stenosis severity by adding the arterial wall and temporal blood response to the developed model.
{"title":"Influence of Arterial Wall Elasticity on Blood Flow Dynamic Factors of Stenotic Carotid Artery","authors":"Muhamed Albadawi, Yasser Abuouf, Mahmoudi Ahmed","doi":"10.1115/imece2021-71625","DOIUrl":"https://doi.org/10.1115/imece2021-71625","url":null,"abstract":"\u0000 Carotid artery is the major blood vessel which carries oxygenated blood to the brain and the face. Atherosclerosis is a major arterial disease characterized by a progressive contraction of the blood vessel. It occurs due to the deposition of cholesterol and lipids beneath the internal layer of the artery which is called stenosis. Carotid artery stenosis causes serious implications which considered one of the leading causes of morbidity and mortality in most countries. The existence of stenosis had a significant effect on the blood flow dynamic factors. Adding the arterial wall response through the wall elasticity will achieve more accurate and realistic flow characteristics. In this study, the arterial wall elasticity through two-way Fluid-Structure Interaction (FSI) was considered to the developed model to calculate the blood flow dynamics. Moreover, blood dynamic factors will be used to investigate the flow characteristics with rigid and elastic arterial wall and temporal blood responses. To estimate the blood dynamic factors, a three-dimensional reconstructed patient-specific carotid artery geometry with realistic boundary conditions is considered. Hence, a three-dimensional comprehensive model including the non-Newtonian Carreau blood flow viscosity model under pulsatile flow conditions is developed. The two-way FSI procedure was performed by applying an arbitrary Lagrangian-Eulerian (ALE) formulation to calculate the arterial response. Results indicated that using FSI has a crucial role in investigating the blood flow dynamic factors which resulted in low shear stress, pressure gradient, and velocity distribution comparing to the rigid arterial wall response. The efficient use of Computational Fluid Dynamics (CFD) has the potential to shed light on the assessment of the stenosis severity by adding the arterial wall and temporal blood response to the developed model.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122314192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microwave ablation (MWA) cures cancer by inserting slender antennas into tumors and producing large amounts of heat to kill cancerous cells. A key challenge is the selective heating of cancer cells without damaging the surrounding tissue, which requires a control of heating power for appropriate temperature distribution. This study established a theoretical simulation model for the microwave ablation of a porcine liver by using a coaxial-slot antenna with 10 slots at high frequencies. The axisymmetric finite element method (FEM) with temperature dependent thermal and dielectric properties was used to describe the MWA distribution in the liver tissue by coupling the electromagnetic wave equations and the bio-heat transfer equations. The results demonstrated that the increase of microwave frequency could improve the therapeutic effect of tumor significantly since it had less collateral damage, more concentrated heated region, and better material response than conventional microwave ablations. For a spherical tumor with 10 mm of radius, the 12 GHz MWA reveals an optimum ablation performance with 21.0% of the collateral damage at the radius direction, and 5.5% of the collateral damage at the axial direction, respectively. The results show that the 12 GHz MWA produces more concentrated heat, causes the greatest difference in temperature-rise between the tumor tissues and the healthy tissues, and significantly reduces the over-treatment region for spherical tumor.
{"title":"Theoretical Evaluation of Heat Transfer in Liver Tumor Microwave Ablation Using a 10-Slot Antenna at High Frequencies","authors":"Yanbin Qin, Nanxi Li, Baolin Liu","doi":"10.1115/imece2021-73846","DOIUrl":"https://doi.org/10.1115/imece2021-73846","url":null,"abstract":"\u0000 Microwave ablation (MWA) cures cancer by inserting slender antennas into tumors and producing large amounts of heat to kill cancerous cells. A key challenge is the selective heating of cancer cells without damaging the surrounding tissue, which requires a control of heating power for appropriate temperature distribution. This study established a theoretical simulation model for the microwave ablation of a porcine liver by using a coaxial-slot antenna with 10 slots at high frequencies. The axisymmetric finite element method (FEM) with temperature dependent thermal and dielectric properties was used to describe the MWA distribution in the liver tissue by coupling the electromagnetic wave equations and the bio-heat transfer equations. The results demonstrated that the increase of microwave frequency could improve the therapeutic effect of tumor significantly since it had less collateral damage, more concentrated heated region, and better material response than conventional microwave ablations. For a spherical tumor with 10 mm of radius, the 12 GHz MWA reveals an optimum ablation performance with 21.0% of the collateral damage at the radius direction, and 5.5% of the collateral damage at the axial direction, respectively. The results show that the 12 GHz MWA produces more concentrated heat, causes the greatest difference in temperature-rise between the tumor tissues and the healthy tissues, and significantly reduces the over-treatment region for spherical tumor.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113936807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional trajectory planning approaches are currently lacking in intelligence and autonomy. We used the reinforcement learning approach to solve the autonomous trajectory planning of the robot arm to avoid obstacles with uniform motion and hit the target point quickly with obstacle avoidance planning for surgical robots taken as the practical background. We used the algorithm of experience playback mechanism combined with off-policy DDPG based on reinforcement learning, and after several iterations, the robot completed trajectory planning with obstacle avoidance autonomously. Moving obstacles were added to roughly simulate the autonomous obstacle avoidance of a surgical robotic arm with moving medical personnel or mobile instruments in the operating room, based on the simple trajectory planning example of Open-AI Open-Source Project Baseline, combined with the research context. Sparse rewards were used for each iteration based on the HER algorithm, so that each attempt could gain experience. The HER-DDPG method can quickly complete the manipulator’s trajectory planning in a simulation environment, which is critical for the surgical robot’s autonomous positioning in the real world. Furthermore, the experience playback system has been tested to allow full use of sparse rewards and handle parallel tasks equally well.
{"title":"Dynamic Trajectory Planning of a 7-DOF Surgical Robot Based on HER-DDPG Algorithm","authors":"Qitao Hou, Chenchen Gu, Xiaoyu Wang, Yating Zhang, Ping Zhao","doi":"10.1115/imece2021-70294","DOIUrl":"https://doi.org/10.1115/imece2021-70294","url":null,"abstract":"\u0000 Traditional trajectory planning approaches are currently lacking in intelligence and autonomy. We used the reinforcement learning approach to solve the autonomous trajectory planning of the robot arm to avoid obstacles with uniform motion and hit the target point quickly with obstacle avoidance planning for surgical robots taken as the practical background. We used the algorithm of experience playback mechanism combined with off-policy DDPG based on reinforcement learning, and after several iterations, the robot completed trajectory planning with obstacle avoidance autonomously. Moving obstacles were added to roughly simulate the autonomous obstacle avoidance of a surgical robotic arm with moving medical personnel or mobile instruments in the operating room, based on the simple trajectory planning example of Open-AI Open-Source Project Baseline, combined with the research context. Sparse rewards were used for each iteration based on the HER algorithm, so that each attempt could gain experience. The HER-DDPG method can quickly complete the manipulator’s trajectory planning in a simulation environment, which is critical for the surgical robot’s autonomous positioning in the real world. Furthermore, the experience playback system has been tested to allow full use of sparse rewards and handle parallel tasks equally well.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128987818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Tamura, K. Makabe, Hatsune Yamashita, Junichi Hongu
Vascular smooth muscle cells (SMCs) in the extracellular matrix adapt to their surrounding environment in vivo with its contraction and relaxation. As blood pressure increases, the circumferential stress on the aortic wall also increases. The major components of the media are SMCs, so SMCs should regulate the vessel diameter and the mechanical balance of the aortic medial ring. Thus, it is important to clarify how external forces on SMCs are transmitted through the intracellular components. Nuclei may sense changes in the applied mechanical stretch via stress fibers (SFs) or focal adhesions (FAs). However, there is little quantitative information available about the mechanical contribution of SFs and FAs to whole-cell mechanical events such as uniaxial stretching. In the present study, therefore, we developed a finite element model of a cultured SMC, with contractile SFs, on a silicone substrate, and applied a uniaxial stretch, to investigate the mechanotransduction pathways involved in SMCs. We revealed that the initial orientation angle of the SFs was closely correlated with their resultant stretch, and the magnitude of the biomechanical force exerted by SFs.
{"title":"Finite Element Model of a Cultured Vascular Smooth Muscle Cell Subjected to Uniaxial Stretch: Effect of Orientation Angle of Stress Fibers on Biomechanical Responses","authors":"A. Tamura, K. Makabe, Hatsune Yamashita, Junichi Hongu","doi":"10.1115/imece2021-68844","DOIUrl":"https://doi.org/10.1115/imece2021-68844","url":null,"abstract":"Vascular smooth muscle cells (SMCs) in the extracellular matrix adapt to their surrounding environment in vivo with its contraction and relaxation. As blood pressure increases, the circumferential stress on the aortic wall also increases. The major components of the media are SMCs, so SMCs should regulate the vessel diameter and the mechanical balance of the aortic medial ring.\u0000 Thus, it is important to clarify how external forces on SMCs are transmitted through the intracellular components. Nuclei may sense changes in the applied mechanical stretch via stress fibers (SFs) or focal adhesions (FAs). However, there is little quantitative information available about the mechanical contribution of SFs and FAs to whole-cell mechanical events such as uniaxial stretching.\u0000 In the present study, therefore, we developed a finite element model of a cultured SMC, with contractile SFs, on a silicone substrate, and applied a uniaxial stretch, to investigate the mechanotransduction pathways involved in SMCs. We revealed that the initial orientation angle of the SFs was closely correlated with their resultant stretch, and the magnitude of the biomechanical force exerted by SFs.","PeriodicalId":314012,"journal":{"name":"Volume 5: Biomedical and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131980616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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