A Child's Body-Powered Prehensor with Adaptive Grasp

描述（由申请人提供）：传统的身体动力辅助器具旨在帮助有上肢缺陷的儿童，已被证明不适合某些活动，最明显的是玩耍。这些系统中提供抓握功能的关键组件，称为抓握器或终端设备，必须在儿童希望完成的活动的功能和希望孩子拥有正常外观的父母的外观之间取得平衡。父母通常会选择模仿手部解剖结构的美容器械，而研究表明，孩子们更喜欢功能更强的器械。那些选择功能更强的设备的人通常会发现，现有设备在游戏活动中的表现令人失望或不足，因为它们需要太多的缆绳移动或操作效率低下，并且需要太大的缆绳张力才能达到抓取的效果。这些问题导致许多儿童在本应学习终身义肢使用技能的时候，却找不到可接受的义肢。在第一阶段，ADA展示了专门为儿童日常活动设计的抓握器的技术可行性。设计了一种自适应手指，提供儿童主要使用的封闭抓握，而不是成人常见的高强度捏握。还包括一个可变机械优势（VMA）抓取引擎，有效地将电缆偏移和张力转化为质量，稳定的抓取。该发动机显著提高了抓地力与输入电缆张力的比率（称为前向力比，FFR）。与目前平均FFR为0.2的设备相比，ADA的原型实现了0.78的最大FFR。最终的结果是，孩子们可以用更少的体力消耗获得更高水平的抓握力，让他们自由地做他们最想做的事情——玩耍。第二阶段的工作将集中于改进第一阶段已证实的原型设计，以达到以下目的：1)将其商业制造成本降至最低，以使经济拮据的家庭受益；2)在儿童用户的实际服务中验证其性能。为了获得商业认可，将纳入诸如被动承载能力和改进外观等附加功能。ADA将与Shriners医院网络中的执业义肢专家合作，从设计阶段到临床评估。通过与Shriners的合作，ADA将与全国领先的儿童假肢护理和设备供应商建立早期的工作关系。在整个过程中，ADA将通过不断与外部合作伙伴合作，保持对商业可行性的关注，以确保满足儿童的抓取需求仍然是努力的核心和清晰的焦点。如果成功，第二阶段的努力将生产出一种功能优于目前所有可用的传统抓握器的儿童抓握器。为了确保父母和孩子的成功，ADA将包括市场驱动的外观特征，以及自适应抓取、VMA和被动持有能力。第二阶段的努力将利用这项技术创建一个对第三阶段投资者有吸引力的实体。由于市场规模小，有上肢缺陷的儿童只能使用不适合他们特殊需要的假肢。本研究旨在开发一种功能性抓握器，专门设计在日常使用和美容接受方面优于现有设备。

DESCRIPTION (provided by applicant): Conventional body-powered assistive appliances intended to help children having upper limb deficiencies have proven inadequate for some activities, most notably play. The critical component in these systems that contributes grasp functionality, called a prehensor or terminal device, must strike a balance between functionality for activities children wish to accomplish and cosmesis for parents who desire their child have a normal appearance. Parents most often select more cosmetic devices designed to mimic the anatomical hand, while studies have shown children prefer devices that are more functional. Those who do select more functional devices often find existing units offer disappointing or inadequate performance for play activities as they require too much cable excursion or operate inefficiently and demand too much cable tension to effect grasp. These problems leave many children without an acceptable device at precisely the time they should be learning lifelong prosthetics usage skills. In Phase I, ADA demonstrated the technical feasibility of a prehensor designed specifically for children's daily activities. An adaptive digit was designed that provides the enclosing grasp children primarily use as opposed to high-force pinching grasp common for adults. Also included was a Variable Mechanical Advantage (VMA) grasping engine that efficiently transforms cable excursion and tension into quality, stable grasp. This engine significantly improves the ratio of grip force achieved to the input cable tension (called the forward force ratio, FFR). ADA's prototype achieved a maximum FFR of 0.78, as compared to current devices which average an FFR of 0.2. The end result is that children can achieve higher levels of gripping force with less physical exertion, freeing them to do what they desire most-play. This Phase II effort will focus on refining the proven Phase I prototype design to 1) minimize its commercial manufacturing cost to benefit families of limited means and 2) validate its performance in actual service with children users. To gain commercial acceptance, additional features such as passive holding capacity and improved cosmesis will be incorporated. ADA will work with practicing prosthetists in the Shriners Hospital network through the design phase and into clinical evaluations. By partnering with Shriners, ADA will establish an early, working relationship with the nation's leading provider of child's prosthetic care and equipment. Throughout, ADA will maintain focus on commercial viability by constantly working with outside partners to ensure satisfying children's grasping needs remain central to the effort and in crisp focus. If successful, the Phase II effort will produce a child's prehensor that is functionally superior to all currently available conventional prehensors. To ensure success with parents as well as children, ADA will include market-driven cosmetic features in addition to adaptive grasp, VMA, and passive holding capability. The Phase II effort will leverage this technology to create an entity that will be attractive to Phase III investors. Due to the small market size, children with upper limb deficiencies are made to get by with prosthetics not suited to their special needs. This research seeks to develop a functional prehensor designed specifically to outperform available devices in both daily use and cosmetic acceptance.