Neuromorphic Control Systems
Legged locomotion and object manipulation are examples of activities that are routinely performed by biological systems in a highly functional and elegant manner. Neuromorphic engineering seeks to utilize biological designs, specifically architectural and operational principles of neural system function, in order to develop improved engineered systems. At ANS, we are designing algorithms and electronic circuits that mimic the functionality of neuromotor control systems. In collaboration with our commercial and clinical partners, we are translating the result of these engineering design efforts into practical systems to provide improved mobility and exercise options.
R&D projects in this area include:
- neuromorphic control of cyclic movements using electrical stimulation
- neuromorphic control of powered prostheses and orthoses
Adaptive Stimulator for Exercise and Rehabilitation
Key Personnel: James J. Abbas, PhD (PI on subcontract); ANS/Bioengineering
Richard Herman, MD (Banner Good Samaritan Medical Center)
Eric Hartman (PI on primary contract, customKYnetics, Inc.)
Sponsor: NIH-National Center for Medical Rehabilitation Research
primary contract to customKYnetics, Inc. (PI: Hartman)
subcontract to BGSMC/ASU (PI: Abbas; ANS/Bioengineering),
The potential benefits of exercise to people with spinal cord injury (SCI) may be even greater than the benefits enjoyed by the able-bodied population. In addition to the health benefits that have been well-documented for the able-bodied individual, exercise may also provide a mechanism to slow or reverse many of the secondary complications of SCI. Furthermore, participating in a regular exercise program may provide opportunities for an individual with SCI to participate in a wider range of rehabilitation programs. Unfortunately, many of the options for exercise programs and equipment that are available to the able-bodied population are not accessible to the SCI population, while the options that are accessible to people with SCI are often expensive and/or not readily available for use.
In this work, we propose to develop a prototype electrical stimulation system that addresses many of the limitations of existing systems for exercise in SCI. The proposed system will be designed for use in exercise protocols to reduce muscle atrophy and as a therapeutic tool in motor retraining paradigms.
The target populations for this device are: 1) individuals with complete or incomplete SCI who are interested in improving their physical fitness through electrically stimulated lower-extremity exercise, 2) individuals with complete or incomplete SCI who seek to develop or maintain adequate muscle strength to allow routine use of an FES system for standing, and 3) individuals with incomplete spinal cord injury, brain injury, or stroke who have the potential to regain voluntary lower extremity motor function through motor retraining therapy.
The proposed device will be a low-cost, portable, stimulation system for home-based exercise that includes sensors and adaptive control techniques to autonomously custom-fit the stimulation pattern to the user. The adaptive stimulator will generate a desired kinematic waveform without a priori subject-specific information and despite day-to-day and minute-to-minute variations in muscle recruitment properties. The system will be used to exercise the quadriceps muscles in a pre-programmed pattern that can be specified by the clinician for targeted exercise (e.g., strength vs. endurance) or rehabilitation.
The goals of the Phase I project were: 1) to develop a prototype system that implemented the controller calculations and sensor processing on a low-cost digital signal processor (DSP), 2) to test the prototype system in a limited study, and 3) to develop and benchmark test a DSP-based approach for generating stimulus pulses with minimal hardware components. The Phase I aims have been achieved and progress to-date is summarized in the report below. The Phase I results clearly demonstrate the feasibility of our approach and have laid a strong foundation for the proposed Phase II effort.
In Phase II, we will: 1) develop sensors to provide direct knee angle measurements and simplify donning and calibration, 2) develop a prototype adaptive stimulator for use by individuals with complete or incomplete SCI, 3) develop a clinical software suite for protocol programming, performance evaluation, and documentation, 4) assess the efficacy of the device in a study involving individuals with complete injuries who wish to increase muscle mass, strength and endurance through a long-term electrical stimulation based training protocol, and 5) assess the efficacy of the device in a study involving individuals with incomplete injuries who have some degree of voluntary control over the target muscles and who wish to improve muscle condition and potentially improve their ability to perform functional voluntary activities.
Neuromorphic Control System for Powered Limb Splints
Key Personnel: R. Jung, PhD (PI, AdveNSys, LLC)
J.J. Abbas, PhD (PI on ASU subcontract); ANS/Bioengineering
Sponsor: U.S. Army
AdveNSys will develop a suite of products to provide new orthotic and prosthetic options for people with lower limb dysfunction or lower limb amputation. We will enhance our biologically-inspired adaptive neuromorphic control systems technology and integrate it with biomorphic compliant actuators, advanced sensor systems, and lightweight orthotic/prosthetic components to produce a suite of products to provide locomotion assistance. These systems will be used for acute-care in combat settings to provide functional bipedal mobility to injured soldiers. In addition, the systems will be used in post-acute and chronic care situations to enable injured individuals to more fully participate in a wide range of activities in military and civilian settings.
AdveNSys will partner with clinical, industrial and academic research institutions to design, develop and evaluate this next-generation product suite that promises to revolutionize technology to overcome lower limb dysfunction both in military and civilian settings. The Phase II efforts will help mature the AdveNSys technology and deliver critical engineering models that will serve as the basis for development of production prototypes for mass production. It is a critical step in AdveNSys vision to Advancing Everyday Mobility for the 7.4 million people who currently use assistive technology devices for mobility impairments.