A Biomimetic Prehensile Digit for Upper-Limb Prostheses

DESCRIPTION (provided by applicant): Among amputation types involving the upper limbs, partial hand is the most prevalent by far and among the most challenging for prosthetists to address well. Sound side overreliance for these amputees gives rise to a high prevalence of contralateral overuse syndrome (COS), a progressive, painful, and debilitating condition. Research shows that prostheses reduce the incidence of COS by encouraging more balanced, bimanual limb usage. Consequently, there is strong interestin developing new prosthetic options for partial hand amputees. At the same time, in certain developing countries the use of forced amputations to incite terror combined with deeply entrenched cultural stigmas have produced a growing population of amputeesabroad who need functional and more realistic looking hand prostheses to help them reintegrate and regain social acceptance. Invisible Hand Enterprises, LLC (IHE) is developing a new articulated digit technology it believes holds the potential to help satisfy both of these overlapping needs by making possible the creation of affordable partial and whole hand prostheses having excellent cosmesis and grasp functionality. In Phase I of this three-phase Small Business Innovation Research (SBIR) program, IHE will complete the development of its digit technology and initiate field validation testing with volunteer subjects to assess whether commercial development is justified. IHE's digit system exploits properties and functional characteristics of synthetic textile fibers to replicate key functions of ligaments, tendons, and cartilaginous articulations within the anatomical finger, along with bone elements fabricated from engineering resin. This new prehensile digit technology is purposefully robust, lightweight, inexpensive, and achieves excellent adaptive grasp with strikingly lifelike movement. IHE will collaborate with Lake Prosthetics and Research, LLC (LPR) to refine its designs and maximize their clinical versatility, addressing frequently overlooked considerations such as means of attachment, adjustable positioning, and efficient cable routing. Prototype digits will be fabricated and incorporated into three (3) partial and three (3) whole hand prostheses. Volunteer subjects will wear these prostheses to assess the digits' performance under strenuous real-world operating conditions. Phase II comprises making design refinements to address issues invariably identified in Phase I, expanding testing to include more demanding tasks and environments, and establishing manufacturing infrastructure to support Phase III commercialization activities. IHE exists to create technologically and economically appropriate prosthetics options for disadvantaged amputees worldwide, enabling them to regain functionality, personaldignity, joy in living, and social, cultural, and tribal acceptance. The company's fundamental objective is to delight amputees by providing tools that help them relish living and enjoy an even higher quality of life. IHE asserts the work described in this submittal is important and worthwhile, and wholly consistent with the spirit and purposes of the National Institute of Health's (NIH) SBIR program. PUBLIC HEALTH RELEVANCE: Invisible Hand Enterprises' innovative new prehensile digit technology uses synthetic textile fibers to realize modular fingers that are robust, lightweight, and inexpensive. Designed for off-the-shelf use by the prosthetist, they are intended for both partial and whole hand prostheses, providing secure, stable grasp and realistic movement for excellent cosmesis. The technology purposefully addresses needs within the United States and in developing countries for technologically and economically appropriate options that help users participate and contribute to their families and society.