Tactile Sensing Reflexes for Advanced Prosthetic Hands
Abstract
Objectives and Rationale: Much money and effort have gone into developing new technologies for prosthetic hands that have as many joints as human hands and that can be controlled directly by thought, but actual performance is no better than that of much simpler hands that have been available for decades. While costs of care for upper-limb amputee patients have more than quadrupled for Veterans from the Vietnam War to Veterans from the Operation Iraqi Freedom and Operation Enduring Freedom conflicts, overall satisfaction and quality of life as reported by the amputees is no better. One of the most significant challenges with prosthetic hands is performing precise or delicate tasks, such as grasping fragile objects without dropping or damaging them. Without the ability to feel, users must rely almost entirely on visual observation to adjust their EMG (electromyography) command signals. They must move slowly with intense concentration to achieve at best marginal and highly inconsistent performance. We have shown that adding touch sensors and intelligent reflexes to prosthetic fingertips can greatly improve both the speed and consistency with which delicate grasping tasks can be performed. These methods are modeled after capabilities we know to exist in the human hand that enable effortless grasping with minimal concentration. This research seeks to build on these previous results by translating the sensing technology into a low-cost and highly robust system integrated with commercially available prosthetic hands. Studies will be carried out to demonstrate how this technology improves the quality of life and satisfaction for upper-limb amputees. Potential Impact: There are over 500,000 people living with upper-extremity limb loss in the United States alone, many resulting from traumatic injuries such as those sustained from improvised explosive devices (IEDs) that wound those putting their lives on the line to serve our country. In the event of such tragedy, state-of-the-art prosthetic hands are designed to restore the function of the lost limbs. Electrical signals recorded from remaining muscles in the stump allow the prosthesis operator to open and close an electrically powered prosthetic hand. Without the ability to feel what is happening at the fingertips, however, the operator must watch the hand carefully and try to time the signals that he/she generates in those muscles, a difficult task requiring substantial focus. As a result of these limitations, many amputees tend to reject their prosthesis due to its limited function and utility. Within the 4-year research plan, we will incorporate our new sensing technology and proven control system into commercially available prostheses and demonstrate their improved function and usability without a substantial increase in cost or complexity. Such technology will make these devices acceptable to amputees and improve their confidence in controlling their prosthetic hand. A preliminary study has already produced promising results to restore grasping capabilities to near human hand performance and we have worked closely with the leading manufacturer of prosthetic hands, so we expect the technology to be ready for commercialization at the completion of this project. Beyond this initial significant impact, the technologies that are being developed can be added to any active prosthesis, including advanced hands still under development. Benefits to Service Members, Veterans, Family Members: Advancements in body armor and battlefield medicine have greatly reduced the mortality rate of Soldiers wounded in action, while subsequently increasing the incidence of trauma and amputations. More than 1,570 US Veterans of Iraq and Afghanistan have lost one or more limb. These young, ambitious, and otherwise physically capable and motivated individuals who have suffered such misfortune expect to benefit from the high-tech world in which they are raised, only to find that
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 04, 2016
- Source ID
- W81XWH1510149
Entities
People
- Jeremy Fishel
Organizations
- SynTouch (United States)
- United States Army