Cleveland Clinic develops bionic arm that restores ‘natural behaviors’


2021-09-02 18:30:07 Roboticstrends


Cleveland Clinic researchers have engineered a “first-of-its-kind bionic arm” for patients with upper-limb amputations that allows wearers to think, behave and function like a person without an amputation, according to new findings published in Science Robotics. The Cleveland Clinic-led international research team developed the bionic system that combines three important functions – intuitive motor control, touch and grip kinesthesia, the intuitive feeling of opening and closing the hand. Collaborators included University of Alberta and University of New Brunswick. “We modified a standard-of-care prosthetic with this complex bionic system which enables wearers to move their prosthetic arm more intuitively and feel sensations of touch and movement at the same time,” said lead investigator Paul Marasco, PhD, associate professor in Cleveland Clinic Lerner Research Institute’s Department of Biomedical Engineering. “These findings are an important step towards providing people with amputation with complete restoration of natural arm function.” The system is the first to test all three sensory and motor functions in a neural-machine interface all at once in a prosthetic arm. The neural-machine interface connects with the wearer’s limb nerves. It enables patients to send nerve impulses from their brains to the prosthetic when they want to use or move it, and to receive physical information from the environment and relay it back to their brain through their nerves. The artificial arm’s bi-directional feedback and control enabled study participants to perform tasks with a similar degree of accuracy as non-disabled people. “Perhaps what we were most excited to learn was that they made judgments, decisions and calculated and corrected for their mistakes like a person without an amputation,” said Dr Marasco, who leads the Laboratory for Bionic Integration. “With the new bionic limb, people behaved like they had a natural hand. Normally, these brain behaviors are very different between people with and without upper limb prosthetics.” Dr Marasco also has an appointment in Cleveland Clinic’s Charles Shor Epilepsy Center and the Cleveland VA Medical Center’s Advanced Platform Technology Center. The researchers tested their new bionic limb on two study participants with upper limb amputations who had previously undergone targeted sensory and motor reinnervation – procedures that establish a neural-machine interface by redirecting amputated nerves to remaining skin and muscles. Due to the study’s small size, additional research will be important. In targeted sensory reinnervation, touching the skin with small robots activates sensory receptors that enable patients to perceive the sensation of touch. In targeted motor reinnervation, when patients think about moving their limbs, the reinnervated muscles communicate with a computerized prosthesis to move in the same way. Additionally, small, powerful robots vibrate kinesthetic sensory receptors in those same muscles which helps prosthesis wearers feel that their hand and arm are moving. While wearing the advanced prosthetic, participants performed tasks reflective of basic, everyday behaviors that require hand and arm functionality. With their newly developed advanced evaluation tools, the researchers assessed how performance with the bionic limb compared to that of non-disabled people and people with amputations who have traditional prosthetic devices. They also compared how people with the advanced prosthetic fared when the three sensory and motor modalities were enabled together versus individually. According to Dr Marasco, because people with traditional prosthetics cannot feel with their limbs, they behave differently than people without an amputation while completing tasks during daily living. For example, traditional prosthesis wearers must constantly watch their prosthetic while using it and have trouble learning to correct for mistakes when they apply too much or little force with their hand. With the new artificial arm and the advanced evaluation tools, the researchers could see that the study participants’ brain and behavioral strategies changed to match those of a person without an amputation. They no longer needed to watch their prosthesis, they could find things without looking, and they could more effectively correct for their mistakes. “Over the last decade or two, advancements in prosthetics have helped wearers to achieve better functionality and manage daily living on their own,” said Dr Marasco. “For the first time, people with upper limb amputations are now able to again ‘think’ like an able-bodied person, which stands to offer prosthesis wearers new levels of seamless reintegration back into daily life.” Beyond this study, the new outcome measurements related to brain behavior and functionality that the international team developed to evaluate the bionic system can be applied to any upper limb prosthetic or deficit that involves sensation and movement. The study was funded in part by the Defense Advanced Research Projects Agency, a research and development arm of the Department of Defense. In 2018, Dr Marasco published a seminal paper in Science Translational Medicine on a new method of restoring natural movement sensation in patients with prosthetic arms.
根据发表在《科学机器人学》上的新发现,克利夫兰诊所的研究人员为上肢截肢患者设计了一种“首创的仿生手臂”,允许佩戴者像没有截肢的人一样思考、行为和功能。 克利夫兰诊所领导的国际研究小组开发了这种仿生系统,它结合了三个重要功能--直观的运动控制、触摸和抓握动觉、打开和关闭手的直观感觉。 合作者包括艾伯塔大学和新不伦瑞克大学。 克利夫兰诊所勒纳研究所生物医学工程系副教授、首席研究员保罗·马拉斯科博士说:“我们用这种复杂的仿生系统改造了一种标准护理假肢,使佩戴者能够更直观地移动假肢,同时感受到触摸和运动的感觉。” “这些发现是为截肢者提供完全恢复自然手臂功能的重要一步。” 该系统是第一个在人工手臂中同时测试神经-机器接口中所有三种感觉和运动功能的系统。神经-机器接口与佩戴者的四肢神经相连。 它使患者在想使用或移动假肢时,能够从大脑向其发送神经脉冲,并从环境中接收物理信息,并通过神经将其传递回大脑。 人工手臂的双向反馈和控制使研究参与者能够以与非残疾人相似的精确度完成任务。 “也许我们最兴奋的是,他们像一个没有截肢的人一样做出判断、决定、计算和纠正自己的错误,”领导仿生集成实验室的马拉斯科博士说。 “有了新的仿生肢体,人们的行为就像有了一只天然的手。通常情况下,这些大脑行为在有和没有上肢假肢的人之间是非常不同的。“ 马拉斯科博士还在克利夫兰诊所的查尔斯·肖尔癫痫中心和克利夫兰弗吉尼亚州医疗中心的先进平台技术中心预约。 研究人员在两名上肢截肢的研究参与者身上测试了他们新的仿生肢体,他们以前接受了有针对性的感觉和运动神经再支配--通过将截肢神经重新定向到剩余的皮肤和肌肉来建立神经-机器接口的过程。 由于这项研究规模较小,额外的研究将是重要的。在有针对性的感觉神经再支配中,用小机器人触摸皮肤会激活感觉受体,使患者能够感知触摸的感觉。 在有针对性的运动神经再支配中,当病人想要移动他们的四肢时,神经再支配的肌肉会与计算机化的假体交流,以同样的方式移动。 此外,小而强大的机器人振动这些肌肉中的动觉感受器,帮助假肢佩戴者感觉他们的手和手臂在移动。 在佩戴先进的假肢时,参与者进行了反映基本日常行为的任务,这些行为需要手和手臂的功能。 利用他们新开发的先进评估工具,研究人员评估了仿生肢体与非残疾人和使用传统假肢的截肢者相比的性能。 他们还比较了使用先进假肢的人在三种感觉和运动方式一起启用时的表现,以及单独启用时的表现。 根据马拉斯科博士的说法,因为传统假肢的人不能感觉到他们的四肢,他们在日常生活中完成任务时的行为与没有截肢的人不同。 例如,传统的假肢佩戴者在使用时必须不断观察他们的假肢,当他们用手用力过大或过小时,他们很难学习纠正错误。 有了新的人工手臂和先进的评估工具,研究人员可以看到研究参与者的大脑和行为策略发生了变化,与没有截肢的人相匹配。 他们不再需要看他们的假肢,他们可以不用看就能找到东西,他们可以更有效地纠正他们的错误。 马拉斯科博士说:“在过去的一二十年里,假肢的进步帮助佩戴者实现了更好的功能,并独自管理日常生活。” “上肢截肢的人现在第一次能够像一个健全的人一样再次‘思考',这将为假肢佩戴者提供新水平的无缝重返日常生活。” 除了这项研究,国际小组为评估仿生系统而开发的与大脑行为和功能有关的新结果测量可以应用于任何涉及感觉和运动的上肢假肢或缺陷。 这项研究的部分资金来自国防部的一个研究和开发部门--国防高级研究计划局。 2018年,马拉斯科博士在《科学转化医学》上发表了一篇开创性的论文,内容是一种恢复假肢患者自然运动感觉的新方法。