Though there have been many advances in prosthetic technologies, existing systems are significantly limited in their ability to fully restore function after limb loss. These limitations are manifest in the types-of activities that can be achieved, the ease with which the tasks can be performed and the richness of the experience. Truly advanced prosthetic systems will require seamless integration of the intact sensory-motor living system with advanced highly capable artificial limbs. Our bioengineering research partnership proposes to develop an advanced prosthetic system that uses electrodes implanted within the fascicles of peripheral nerves to provide upper extremity amputees with sensory feedback and active volitional control of the prosthesis. Two specific aims will be pursued. In the first aim of the project, which will focus on sensation, we will develop a system that can be readily evaluated in trials with human subjects. This work will utilize well-established implantable neural stimulation technology in a novel manner to elicit meaningful sensations of hand opening and grip force. This technology will be designed and implemented through clinical deployment of a prosthetic hand system in transradial amputees. In the second aim, we will focus on using the neural interface to provide the dual capabilities of sensation and control. This enhanced version of the technology will provide both the ability to stimulate afferent fibers in order for eliciting sensations and the ability to record from efferent fibers for harnessing signals to control the prosthesis. A key feature of this system will be bidirectional communication (to and from the implanted stimulator) at speeds that enable real-time sensorimotor control of the prosthesis. This technology will be designed and developed and its capabilities will be demonstrated in experiments using an animal model. The proposed work will bring together a multidisciplinary team with expertise in rehabilitation, biomedical engineering, wireless and sensor technology development, kinesiology and neurophysiology from Arizona State University, hand surgery and occupational therapy practice at Mayo Clinic Arizona in Scottsdale, AZ, aprosthetics practice in Phoenix, AZ, a leading international medical neural implant device company, and a leading U.S. manufacturer of myoelectric and externally powered prosthetic arm systems. Key consultants with expertise in FDA processes and Technology Transfer will be part of the steering committee. Our long term goal is clinical delivery of prosthetic systems that will ultimately provide multimodal sensory perception to the user from the prosthesis and provide dynamic control of the prosthesis by capturing the intent of the user. More than 1.2 million amputees live in the US alone and of these 70% have below elbow amputations. The new technology will benefit these users in daily living tasks and provide them increased digit and thumb movement and dexterity, in addition to decreased requirement for visual attention.
