Adaptive Control of Flexion Withdrawal Reflex Stimulator for Locomotor Rehabilita

Customkynetics, Inc., Versailles KY

Investigators

Abstract

[unreadable] DESCRIPTION (provided by applicant): Recovery of independent locomotion is among the most significant therapeutic aims following incomplete spinal cord injury (iSCI) and may lead to dramatic improvements in quality of life for the affected individual as well as dramatic cost savings to both the affected individual and to the health care system. Several studies from various research groups have shown that functional electrical stimulation (FES) used in conjunction with bodyweight supported gait training is a safe and effective method for retraining the neural circuits to improve locomotion. FES may be used to either directly stimulate the tibialias anterior to assist with foot-drop OR to elicit the flexion withdrawal reflex (FWR) resulting in hip/knee flexion and ankle dorsiflexion. FES for foot drop is commonly used and several commercial products have resulted. Efficacy of the FWR technique has been demonstrated for individuals undergoing rehabilitation following iSCI. While FWR offers several clinically significant advantages in locomotor retraining, widespread clinical acceptance of the technique has not been achieved. We assert that FWR would be more widely practiced in gait rehabilitation: 1) if a low cost, practical, comprehensive system were available to implement the technique, and 2) if the system involved an FES unit that automatically controlled stimulation intensity and timing such that the therapist did not have to custom fit the stimulation to the client or adjust the stimulation pattern to maintain performance. We propose GaitSTIM", a novel rehabilitation system indicated for FES-augmented walking therapy. Offering foot-drop and FWR operating modes, FES will be delivered by a device with autonomous, adaptive stimulation control and completely integrated sensing technologies. The system will additionally offer audible/visual cues to engage the client in the therapy and performance-based reports for clinicians, which may assist in prescription and provide the documentation necessary to justify additional therapeutic sessions. The goals of this Phase I SBIR project are to demonstrate feasibility of our concept sensor-based adaptive stimulation approach for control of the FWR response. We will: 1) develop and fabricate a proof-of-concept sensing system to test the FWR operating mode; 2) develop adaptive stimulation control algorithms to modulate the FWR stimulus based on measurements from our sensors; and 3) validate the sensor-based adaptive stimulation control concept in a feasibility study in which individuals with iSCI perform overground walking during which FWR is elicited by either the investigational device or a manually controlled laboratory stimulator. The Phase I feasibility study will be conducted in collaboration with the Miami Project to Cure Paralysis (Miami, FL) under the direction of Edelle Field-Fote, PT, PhD. The target markets for this device would be clinics who serve patients undergoing rehabilitation following iSCI injury or stroke. The target price for the system will be $4000. PUBLIC HEALTH RELEVANCE: The proposed work may benefit public health through development of a clinically viable, electrical stimulation based rehabilitation device for use in locomotor training following spinal cord injury or stroke. Compared to existing devices and techniques, the adaptively controlled electrical stimulation component and tight integration of instrumentation, control, stimulation, visualization, and reporting features may improve efficacy and availability of the therapeutic intervention for many affected individuals. [unreadable] [unreadable] [unreadable] [unreadable]