Vibrotactile Feedback for Prosthetic Limbs II

描述(申请人提供)：通过提供感觉反馈，可以显著提高假肢的功能和用户接受度。其目标是开发一种感觉系统，假肢医生可以将其整合(或改造)到现有的肌电手臂中。该系统是非侵入性的，基于皮肤上的一系列振动致动器(振动器)，用于将编码的感觉信息从假肢输入到残肢的皮肤。动力手臂将针对三类感觉信息：握力、物体滑动和手腕旋转(即旋前/旋后)或手指张开的跨度。先前在开发感官替代的振动触觉策略方面的工作表明，这是一种很有前途的方法。这项研究在市场上的实施受到了阻碍，因为缺乏体积小、功率效率高、能提供局部刺激且与邻近单元几乎没有串扰的振动器。此外，最佳振动触觉反馈编码要求振动频率和强度是独立的。现有的可控震源，如基于手机旋转电机的可控震源或传统的基于螺线管的可控震源，都具有很强的振动频率和强度的相互依赖性。此外，基于螺线管的振动器只有在其共振频率下才有效。第一阶段工作的很大一部分是针对开发和测试一种新的工程方法，以实现强度与频率的分离。开发了一种提供独立频率和强度、小、提供焦点刺激、消耗最小功率和制造成本低的原型驱动器和驱动技术。这个原型在几个非截肢者和截肢者身上进行了测试，取得了很好的结果。这一二期项目的目标是为动力假臂的使用者开发一种感觉反馈系统，以提供可靠、有用的位置、力和滑移信息。振动致动器将进一步发展成为一种易于制造、价格低廉的设备。这些执行机构的直径将小于一叠5美分硬币，重量不到10克，功耗最低；制造成本低；典型运行一年可靠，一次性使用。关节位置传感器(如手腕旋转)和力传感器(如夹紧力)将用于各种假肢。微处理器将使用阶段1中演示的新型感觉编码算法将来自假肢传感器的感觉数据转换为适当的驱动。该感觉反馈系统将在10名上肢截肢者身上进行广泛的测试，以：1)优化编码策略；2)开发软件训练辅助工具；3)展示系统组件和系统的可靠性；以及4)确定使用该感觉系统时假肢功能的改善。与公众健康相关：结合感觉反馈可以极大地提高假体控制的质量。对物体接触、握力和物体滑动的外围知识将使截肢者在使用假肢时有更大的信心，并使其能够处理易碎物品，如手指食物、握手问候或提供婴儿或动物护理。这种生活质量的提高对截肢者来说很重要。

DESCRIPTION (provided by applicant): The functionality and user acceptance of prosthetic limbs can be substantially improved by providing sensory feedback. The goal is to develop a sensory system which prosthetists can incorporate (or retrofit) into presently available myoelectric arms. The system is non-invasive and based on an array of vibrating actuators on the skin (vibrotactors) used to input coded sensory information from the prosthesis to the skin of the residual limb. Three categories of sensory information will be targeted for powered arms: grasp force, object slippage and either wrist rotation (i.e. pronation/supination) or span of finger opening. Prior work in developing vibrotactile strategies for sensory substitution has shown it is a promising approach. The implementation of that research into the marketplace has been held up by a lack of vibrotactors that are small, power efficient and that can provide local stimulation with little cross-talk to adjacent units. Further, optimal vibrotactile feedback codes require that the vibration frequency and intensity be independent. Available vibrators such as cell phone rotary motor based vibrators or traditional solenoid based vibrators have strong co-dependence of vibration frequency and intensity. Further, solenoid based vibrators are only efficient at their resonant frequency. A substantial portion of the Phase 1 effort was directed towards developing and testing a novel engineering approach to the actuators which de-coupled intensity from frequency. A prototype actuator and driving technique was developed which provides for independent frequency and intensity, is small, provides focal stimulation, consumes minimal power and will be inexpensive to manufacture. This prototype was tested on several non-amputee and amputee subjects with excellent results. The goal of this PHASE 2 project is to develop a sensory feedback system for users of powered artificial arms to provide reliable, useful position, force, and slippage information. The vibration actuators will be further developed into a readily manufacturable, inexpensive device. These actuators will be smaller in diameter than a stack of 5 US dimes, weigh less than 10 grams, consume minimal power; be inexpensive to manufacture; be reliable for one year of typical operation, and disposable. Joint position sensors (eg wrist rotation) and force sensors (eg pinch force) will be selected for various prostheses. A microprocessor will convert sensory data from the prosthetic sensor to appropriate actuations using the novel sensory coding algorithms demonstrated in Phase1. The sensory feedback system will be tested extensively with 10 upper extremity amputee subjects to: 1) optimize the coding strategy; 2) develop a software training aid; 3) demonstrate the reliability of the system components and the system; and 4) determine the improvement in functionality of the prostheses when the sensory system is employed. RELEVANCE TO PUBLIC HEALTH: The incorporation of sensory feedback could greatly improve the quality of prosthesis control. Peripheral knowledge of object contact and grip force and object slippage will allow amputees to have increased confidence when using their prosthesis as well as make it possible to handle fragile items such as finger foods, engage in a hand shake greeting, or provide infant or animal care. Such improvements in quality of life are important for amputees.