Sonomyographic Upper Limb Prosthetics: A New Paradigm

在美国，绝大多数与创伤相关的截肢手术都涉及上肢。 在最终接受上肢肌电假体治疗的患者中，大约有一半人 放弃使用该系统，主要是因为它们的功能有限。因此，仍有必要 假肢控制策略的显著改进。 这个生物工程研究项目的目标是开发和临床评估一个原型。 假肢控制系统，使用成像来感觉残留的肌肉活动，而不是肌电。 这种新的方法可以更好地区分前臂肌肉的不同功能区块， 并提供与肌肉活动成比例的强健控制信号。这一改进的感知策略已经 显著提高上肢假体功能的潜力，并提供灵巧的直观 与目前最先进的非侵入性控制方法相比，这是一个重大改进。这 跨学科项目将乔治梅森大学的研究人员、商业合作伙伴聚集在一起 无限生物医学技术和临床医生在MedStar国家康复医院和Hanger诊所工作。 具体目标1：开发和测试紧凑型研究级声学假体系统 我们将开发和评估一个紧凑型、低功耗的声学成像嵌入式系统。我们将优化 实现了多自由度(DOF)的实时分类和控制算法。我们 然后将超声成像换能器集成到测试假体插座中，用于在患有 实验室环境下的经径向肢体丧失。我们将完成系统集成和测试，并对 随着手臂位置和插座负荷的变化，声学信号质量。 具体目标2：评价声学控制与肌电控制的性能 我们将比较SMG和肌电直接控制与模式切换在肌电控制中的性能。 天真的受试者接受了经桡骨截肢手术。评估将使用虚拟现实Fitts定律任务进行 以及使用终端设备的临床结果测量。主要结果衡量标准将是 Shap和次要结果衡量标准将是衣夹重新定位任务。我们将评估直觉性 使用凝视跟踪进行控制，并研究运动质量。我们还将比较以下几种方法的性能 SMG与比例控制肌电模式识别的对比研究 商业公关系统采用相同的结果衡量标准。 该项目的成功完成将导致人类对集成原型的第一次评估 它使用低功率便携式成像传感器和实时图像分析来感知残余肌肉活动 用于假肢控制。从长远来看，我们预计在功能和直观性方面的改进 控制将增加截肢者的接受度。

The vast majority of all trauma-related amputations in the United States involve the upper limbs. Approximately half of those individuals who receive an upper extremity myoelectric prosthesis eventually abandon use of the system, primarily because of their limited functionality. Thus, there continues to be a need for a significant improvement in prosthetic control strategies. The objective of this bioengineering research program is to develop and clinically evaluate a prototype prosthetic control system that uses imaging to sense residual muscle activity, rather than electromyography. This novel approach can better distinguish between different functional compartments in the forearm muscles, and provide robust control signals that are proportional to muscle activity. This improved sensing strategy has the potential to significantly improve functionality of upper extremity prostheses, and provide dexterous intuitive control that is a significant improvement over current state of the art noninvasive control methods. This interdisciplinary project brings together investigators at George Mason University, commercial partners at Infinite Biomedical Technologies and clinicians at MedStar National Rehabilitation Hospital and Hanger Clinic. Specific Aim 1: To develop and test a compact research-grade sonomyographic prosthetic system We will develop and evaluate a compact low-power embedded system for sonomyography. We will optimize and implement algorithms for real-time classification and control with multiple degrees of freedom (DOF). We will then integrate ultrasound imaging transducers within test prosthetic sockets for testing on individuals with transradial limb loss in a laboratory setting. We will complete system integration and testing and evaluate the sonomyographic signal quality with changes in arm position and socket loading. Specific Aim 2: To evaluate performance of sonomyographic control compared to myoelectric control We will compare the performance of SMG vs myoelectric direct control with mode switching in myoelectric- naïve subjects with transradial amputation. Assessment will be performed using a virtual reality Fitts’ law task as well as clinical outcome measures using a terminal device. The primary outcome measure will be the SHAP and secondary outcome measure will be the Clothespin Relocation Task. We will assess intuitiveness of control using gaze tracking, and also study quality of movement. We will also compare the performance of SMG vs myoelectric pattern recognition with proportional control in subjects who have been trained on a commercial PR system using the same outcome measures. The successful completion of this project will lead to the first in human evaluation of an integrated prototype that uses low-power portable imaging sensors and real-time image analysis to sense residual muscle activity for prosthetic control. In the long term, we anticipate that the improvements in functionality and intuitiveness of control will increase acceptance by amputees.