目的针对现有上肢康复训练系统提供视觉和触觉反馈无法关联的问题,本文以自主研发的末端牵引式上肢康复机器人为基础,研究基于力跟踪的视觉与触觉反馈融合技术及其对于上肢训练的效果。方法在虚拟环境中构建力学模型的基础上,本文设计...目的针对现有上肢康复训练系统提供视觉和触觉反馈无法关联的问题,本文以自主研发的末端牵引式上肢康复机器人为基础,研究基于力跟踪的视觉与触觉反馈融合技术及其对于上肢训练的效果。方法在虚拟环境中构建力学模型的基础上,本文设计两种与视觉反馈融合的触觉反馈,分别为两物体间靠近时的排斥力以及物体在介质平面移动时的摩擦力,进而采用基于力跟踪的机器人控制算法将虚拟环境中构建的力反馈通过操纵杆传递给用户。招募8例健康受试者,分别在有无反馈融合模式下进行对照训练。在训练过程中采集受试者与系统的实际和期望力反馈,以及三角肌前束、三角肌后束、肱二头肌和肱三头肌的表面肌电信号。计算有反馈融合模式下期望与实际力反馈之间的均方根误差,用于表征基于力跟踪的多感觉反馈融合效果。计算两种模式下的肌电积分值(i EMG)和单位时间内肌电幅值(EMG/T)以探究融合反馈技术对上肢运动训练的影响。结果在有反馈融合模式下,实际与期望交互力反馈的均方根误差为(0.757±0.171) N;肱二头肌、肱三头肌、三角肌前束和后束的i EMG均显著大于无反馈融合模式下(|t|> 7.965, P <0.001);前三块肌肉的EMG/T显著大于无反馈融合模式下(|t|> 6.363, P <0.001)。结论设计的上肢康复机器人训练系统可以精确地将虚拟环境中构建的力反馈传递给用户,通过视觉与触觉融合增加机器人系统对于训练者外周神经功能的刺激,促使训练者付出更多的努力。基于力跟踪的视觉与触觉反馈融合技术的优势在于可以在虚拟环境中自由构建力学模型,力反馈模式不受空间位置的限制,且可以在同一位置叠加两种以上的力学模型,从而使力反馈效果与虚拟环境中的视觉反馈更加匹配,激发训练者的运动康复兴趣,增强人机交互体验感。展开更多
Background Laparoscopic surgery is a surgical technique in which special instruments are inserted through small incision holes inside the body.For some time,efforts have been made to improve surgical pre training thro...Background Laparoscopic surgery is a surgical technique in which special instruments are inserted through small incision holes inside the body.For some time,efforts have been made to improve surgical pre training through practical exercises on abstracted and reduced models.Methods The authors strive for a portable,easy to use and cost-effective Virtual Reality-based(VR)laparoscopic pre-training platform and therefore address the question of how such a system has to be designed to achieve the quality of today's gold standard using real tissue specimens.Current VR controllers are limited regarding haptic feedback.Since haptic feedback is necessary or at least beneficial for laparoscopic surgery training,the platform to be developed consists of a newly designed prototype laparoscopic VR controller with haptic feedback,a commercially available head-mounted display,a VR environment for simulating a laparoscopic surgery,and a training concept.Results To take full advantage of benefits such as repeatability and cost-effectiveness of VR-based training,the system shall not require a tissue sample for haptic feedback.It is currently calculated and visually displayed to the user in the VR environment.On the prototype controller,a first axis was provided with perceptible feedback for test purposes.Two of the prototype VR controllers can be combined to simulate a typical both-handed use case,e.g.,laparoscopic suturing.A Unity based VR prototype allows the execution of simple standard pre-trainings.Conclusions The first prototype enables full operation of a virtual laparoscopic instrument in VR.In addition,the simulation can compute simple interaction forces.Major challenges lie in a realistic real-time tissue simulation and calculation of forces for the haptic feedback.Mechanical weaknesses were identified in the first hardware prototype,which will be improved in subsequent versions.All degrees of freedom of the controller are to be provided with haptic feedback.To make forces tangible in the simulation,characteristic values 展开更多
文摘目的针对现有上肢康复训练系统提供视觉和触觉反馈无法关联的问题,本文以自主研发的末端牵引式上肢康复机器人为基础,研究基于力跟踪的视觉与触觉反馈融合技术及其对于上肢训练的效果。方法在虚拟环境中构建力学模型的基础上,本文设计两种与视觉反馈融合的触觉反馈,分别为两物体间靠近时的排斥力以及物体在介质平面移动时的摩擦力,进而采用基于力跟踪的机器人控制算法将虚拟环境中构建的力反馈通过操纵杆传递给用户。招募8例健康受试者,分别在有无反馈融合模式下进行对照训练。在训练过程中采集受试者与系统的实际和期望力反馈,以及三角肌前束、三角肌后束、肱二头肌和肱三头肌的表面肌电信号。计算有反馈融合模式下期望与实际力反馈之间的均方根误差,用于表征基于力跟踪的多感觉反馈融合效果。计算两种模式下的肌电积分值(i EMG)和单位时间内肌电幅值(EMG/T)以探究融合反馈技术对上肢运动训练的影响。结果在有反馈融合模式下,实际与期望交互力反馈的均方根误差为(0.757±0.171) N;肱二头肌、肱三头肌、三角肌前束和后束的i EMG均显著大于无反馈融合模式下(|t|> 7.965, P <0.001);前三块肌肉的EMG/T显著大于无反馈融合模式下(|t|> 6.363, P <0.001)。结论设计的上肢康复机器人训练系统可以精确地将虚拟环境中构建的力反馈传递给用户,通过视觉与触觉融合增加机器人系统对于训练者外周神经功能的刺激,促使训练者付出更多的努力。基于力跟踪的视觉与触觉反馈融合技术的优势在于可以在虚拟环境中自由构建力学模型,力反馈模式不受空间位置的限制,且可以在同一位置叠加两种以上的力学模型,从而使力反馈效果与虚拟环境中的视觉反馈更加匹配,激发训练者的运动康复兴趣,增强人机交互体验感。
文摘Background Laparoscopic surgery is a surgical technique in which special instruments are inserted through small incision holes inside the body.For some time,efforts have been made to improve surgical pre training through practical exercises on abstracted and reduced models.Methods The authors strive for a portable,easy to use and cost-effective Virtual Reality-based(VR)laparoscopic pre-training platform and therefore address the question of how such a system has to be designed to achieve the quality of today's gold standard using real tissue specimens.Current VR controllers are limited regarding haptic feedback.Since haptic feedback is necessary or at least beneficial for laparoscopic surgery training,the platform to be developed consists of a newly designed prototype laparoscopic VR controller with haptic feedback,a commercially available head-mounted display,a VR environment for simulating a laparoscopic surgery,and a training concept.Results To take full advantage of benefits such as repeatability and cost-effectiveness of VR-based training,the system shall not require a tissue sample for haptic feedback.It is currently calculated and visually displayed to the user in the VR environment.On the prototype controller,a first axis was provided with perceptible feedback for test purposes.Two of the prototype VR controllers can be combined to simulate a typical both-handed use case,e.g.,laparoscopic suturing.A Unity based VR prototype allows the execution of simple standard pre-trainings.Conclusions The first prototype enables full operation of a virtual laparoscopic instrument in VR.In addition,the simulation can compute simple interaction forces.Major challenges lie in a realistic real-time tissue simulation and calculation of forces for the haptic feedback.Mechanical weaknesses were identified in the first hardware prototype,which will be improved in subsequent versions.All degrees of freedom of the controller are to be provided with haptic feedback.To make forces tangible in the simulation,characteristic values
