1992 — 1996 |
Chizeck, Howard [⬀] Abbas, James (co-PI) |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Bac: Neural Network Control of Oscillatory Movements of Multi-Segmented Musculoskeletal Systems @ Case Western Reserve University
This project will develop an artificial neural network control system for biped locomotion. The intended application is the restoration of locomotion in individuals with neuromotor impairments. The control system will specifically address the problem of adaptively controlling cyclic movements in multi- segmented systems using electrically stimulated muscles as actuators. Characteristic features of vertebrate neuromotor locomotion control systems will be incorporated into this neural network control system. This research is important since the results may be useful in Functional Neuromuscular Stimulation rehabilitative devices that provide electrically stimulated walking in spinal cord injury, stroke and head injury patients.
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0.858 |
2000 — 2002 |
Abbas, James J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Preparatory Adjustments For Improved Standing With Fns
DESCRIPTION: (adapted from Investigator's abstract) The long term goals of this research is to develop practical Functional Neuromuscular Stimulation (FNS) systems for restoring motor function in neurologically-impaired individuals. FNS has been used to restore the ability to stand, step and maneuver in persons with spinal cord injury (SCI) and other neurological disorders that impair lower extremity function. Research results have been encouraging, but lower extremity FNS systems have not yet proven to be clinically viable primarily due to the limited degree of function that has been restored. The investigators will develop and evaluate a system that provides the FNS system user the ability to make two types of preparatory adjustments prior to performing a task: the user will first place their feet in a suitable location and then the user will adjust their posture (i.e. adjust the location of the pelvis with respect to the feet). The role of proper foot placement in standing has not been well characterized, nor has it been exploited in FNS control system design. The majority of the effort will be directed towards investigating the role of foot placement and developing techniques to achieve suitable foot placement in FNS stance. To incorporate the facility for adjusting posture once the feet are in place, the investigators will utilize and build upon the results of their on-going efforts in which they are implementing techniques for on-line postural adjustments. At the completion of this project, they plan to have successfully developed and implemented a novel control system for making preparatory adjustments in FNS standing and to have demonstrated the functional benefits provided by this system. Towards this end, they propose a coordinated effort that will utilize computer simulations with detailed biomechanical models, experiments on able-bodied individuals, and several sets of experiments on spinal cord injured subjects who are standing using FNS systems.
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1 |
2005 — 2008 |
Abbas, James J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Adaptive Electrical Stimulation For Locomotor Retraining @ Arizona State University-Tempe Campus
DESCRIPTION (provided by applicant): Recent studies have indicated that functional recovery of locomotor function after spinal cord injury may be enhanced by performing repetitive stepping movements on a treadmill with a harness for partial body weight support with passive assistance provided by therapists. The putative mechanism that underlies this recovery is activity-dependent plasticity of neural circuits both in the spinal cord and in supraspinal centers. Although results in some subjects have been encouraging, in general, the functional gains that have been demonstrated from locomotor therapy are moderate and there is a high variability across subjects. We believe that the 'standard' form of this therapy (treadmill/harness with passive assistance from therapists) is soundly based on well established principles of motor learning, but the manner in which the therapy is delivered does not enable maximization of the therapeutic effect. We propose that locomotor therapy may be enhanced by: 1) producing sensorimotor patterns that are more 'physiological' - i.e. that include appropriately timed muscle contractions and are therefore more similar to sensorimotor patterns in the intact state and 2) generating movement patterns in a more repeatable manner. Our approach utilizes adaptive control of electrical stimulation to activate muscles in order to generate repeatable movements on the treadmill. We believe that the combination of appropriately timed contractions and repeatable movement patterns will result in an improved form of locomotor therapy. Furthermore, the adaptive nature of the control system may be used to encourage gradual increases in voluntary input, therefore providing a mechanism for weaning the individual from FES-assistance during locomotion. The long-term goal of this work is to develop a system that will provide a more effective and efficient form of locomotor retraining therapy. In this work, we will develop a technique that uses adaptive control of electrically-stimulated muscles to produce repeatable stepping movements with coordinated sensorimotor patterns of activity. The system will use transcutaneous neuromuscular stimulation to assist in movement generation while walking on the treadmill with partial body weight support provided by a harness. Adaptive control techniques will be used to automatically determine an appropriate set of stimulation parameters for a given individual and to automatically adjust the stimulation parameters to account for fatigue and/or motor retraining effects. The goals of the proposed project are to develop the adaptive system and to evaluate its ability to generate specified movement patterns. We will implement the adaptive system and experimentally demonstrate that it is capable of reliably producing stepping movements by individuals with spinal cord injury on a treadmill with partial body weight support. In future work (beyond the scope of this proposal), we will compare the efficacy of adaptive FES-assisted locomotor therapy with other forms of locomotor therapy.
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1 |
2018 — 2021 |
Abbas, James J. Jung, Ranu [⬀] |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Crcns: Improving Bioelectronic Selectivity With Intrafascicular Stimulation @ Florida International University
The network of peripheral nerves offers extraordinary potential for modulating and/or monitoring the functioning of internal organs or the brain. The nervous system functions by generating patterns of neural activity. To influence neural activity for desired outcomes, neural interface technology must access the appropriate peripheral nerve tissue, activate it in a focal targeted manner, and alter the patterns of activity. The anatomical organization of peripheral nerves, which consists of multiple nerve fibers clustered into one or more fascicles, presents opportunities and challenges for precise control of spatiotemporal patterns. The efficacy of peripheral nerve stimulation will depend greatly on the ability of the bioelectronic interface to achieve the specificity that may be required for clinical applications, basic science studies and for augmentation of human capabilities. Systems that enable greater specifictty are likely to achieve a higher degree of functionality with fewer side effects. This work is directed at increasing the specificity that can be achieved with peripheral nerve stimulation in a manner that will enable a wide range of clinical and non clinical applications. lntraneural electrodes that are embedded within the fascicles can utilize low-amplitude electrical pulses to generate an electric field that can preferentially activate small groups of fibers that are close to the electrode. Longitudinal intrafascicular electrodes (LIFEs) allow access to nerve fibers within a fascicle and their mechanical properties are well-suited for chronic use. LIFEs enable activation with sub fascicular specificity, but there is great potential for enhancing their specificity using advanced stimulation strategies. The goal of this US-French collaboration is to achieve high specificity by exploring two approaches: using multiple contacts within a fascicle to direct current (field-steering strategies) and using alternative shapes of stimulation pulses to preferentially activate fibers with specific properties (waveform strategies). The proposal builds on a prior collaboration in which a new hardware platform for stimulation was developed by the French team. Using computational models, we will develop and analyze new strategies for selective stimulation of nerve fibers within individual fascicles. The hardware platform will be enhanced and further developed to enable real-time implementation of the field-steering and waveform strategies with a set of LIFEs. In vivo studies on anesthetized rabbits will assess the ability of the field-steering and waveform strategies to enhance selectivity with intrafascicular stimulation.
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0.946 |
2021 |
Abbas, James J. Jung, Ranu [⬀] |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
C3i Accell: Accelerating Commercialization of a Neural-Enabled Prosthetic Hand System @ Florida International University
PROJECT SUMMARY There is a large and growing population of individuals with upper-limb amputation whose needs are not fully met by current prosthetic hand technology. Our work is based on the notion that prosthetic hand technology that provides task-related sensations will increase proficiency in sensorimotor tasks and therefore allow prosthesis users to participate in a greater range of employment and leisure activities. To achieve this, the Adaptive Neural Systems neural-enabled prosthetic hand (ANS-NEPH) system was designed and developed by our lab in collaboration with industrial and clinical partners. The system uses a wirelessly-controlled implanted neurostimulator and fine-wire longitudinal intrafascicular electrodes to elicit sensations based on signals derived from sensors in an instrumented prosthetic hand. We have an investigational device exemption from the FDA to conduct a longitudinal first-in-human clinical trial. The first subject has been enrolled, implanted, fitted with the external components of the system, and has completed a 2-year post-implant follow-up period. At the conclusion of his participation in the study, he opted to keep the system and now, more than three years post-implant, he continues to use the system at home and in the community. In the parent grant, we are continuing the trial to evaluate clinical safety and device functionality in additional subjects. The primary outcome of the trial will be a demonstration of clinical feasibility of a neural-enabled prosthetic hand system for daily use (for greater than one year) at home or at the workplace that uses wirelessly-controlled implantable stimulation technology. While creation of the system and the on-going clinical trial constitute significant contributions to the field, the clinical impact will be severely muted if we do not deploy the technology in the clinic and commercialize it. With support from the C3i Accell program, we plan to address two key challenges beyond those being addressed in the parent grant that will enhance the impact by moving this technology towards clinical deployment and commercialization. The first challenge is to develop software that will enable clinicians to program the stimulation settings of the ANS-NEPH system safely, effectively, and efficiently in a clinical setting. We will initiate development of the clinician software to program the ANS-NEPH system by using a structured Human Factors Engineering approach with interviews of representative users and formative evaluations of a mock-up to produce a robust set of use-related requirements for the clinician-user interface. The second challenge is to develop a business model that will enable us to operate effectively in both the neurotechnology and prosthetic limb commercial ecosystems. For this, we will develop plans for a business framework that will enable successful commercialization. This will include preparation of strategies for regulatory pre-market approval by the FDA and for reimbursement during the pivotal clinical trial and after commercialization. By addressing these challenges, we anticipate that we can greatly increase the likelihood of successful commercialization and thereby amplify the clinical impact of the parent grant and other federal support for this research program.
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0.946 |