Neural Enabled Prosthesis for Upper Limb Amputees
As we use a hand to manipulate an object, high quality control is enabled by multi-modal, distributed, and graded sensations from somatosensory receptors. Today's motorized upper limb prostheses do not afford amputees with high quality control due to the lack of critical information such as contact force and hand opening, which results in an increased reliance on visual feedback and high attentional demands. It follows that there is a large population of amputees whose needs are not being fully met by current prosthetic hand technology, which results in reduced quality of life.
To address this problem, we, at the Adaptive Neural Systems lab, in collaboration with commercial and clinical partners have developed an Adaptive Neural Systems-Neural-Enabled Prosthetic Hand (ANS-NEPH) system intended to provide the sense of touch, grasp force and hand opening to the user by sending electrical stimulation pulses to nerves of the residual limb. The system includes a neural stimulation device and an instrumented prosthetic hand. It uses signals derived from sensors on the instrumented prosthetic hand to elicit sensations by delivering stimulation via fine-wire longitudinal intrafascicular electrodes (LIFEs) implanted in peripheral nerves of the residual limb.
The technology has received approval from the US Food and Drug Administration as an investigational device and is being evaluated in a clinical trial supported by a grant from the HAPTIX program under the Defense Advanced Research Projects Agency (DARPA).
Neural Enabled Prostheses with Sensorimotor Integration
There are more than 1.7 million individuals living with amputations in the United States alone and this number is projected to reach 3.6 million by 2050. Even though prosthetic technology continues to advance, adequate replacement of the human hand and arm remains one of the most difficult problems facing medical technology. The current “state of the art” upper limb prosthetics remain inadequate as replacements for the lost limb, despite significant advancements in technology. Hence, patient satisfaction, use, and compliance remain less than ideal. A truly advanced prosthetic system will require seamless integration of the intact sensory-motor living system with advanced highly capable artificial limbs. We have developed an advanced prosthetic system that will provide sensory feedback to an upper extremity amputee using sensors embedded in the prosthetic hand to determine fingertip forces and hand opening to control an implanted electrical stimulation device. In turn, the stimulation device elicits sensation by delivering weak electrical pulses via electrodes implanted in the fascicles of the peripheral nerve in the residual arm. The National Institute of Biomedical Imaging & Bioengineering (NIBIB) and National Institute of Child & Human Development (NICHD) fund this endeavor.
Effective and Reliable Peripheral Nerve Recordings
To control a powered prosthesis, an amputee must provide signals to drive the motors. Signals that would be most useful are those that afford a high degree of control, that allow the person to control several joints simultaneously, and that do not incur a high demand on attention. By recording neural activity on from peripheral nerves in the residual limb of an amputee, it may be possible to obtain signals that meet these requirements. This research study is designed to determine if it is possible to obtain such signals in a reliable and repeatable manner. ANS is contracted by the Defense Advanced Research Projects Agency (DARPA) to complete this project.
Towards the Development of an Implanted Neural Stimulation and Recording System
Though there have been many advances in 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. To develop a truly advanced prosthesis that can integrate with the living sensorimotor system, sensory stimulation and neural recording capabilities must be integrated into one package. The purpose of this study is to develop an implantable stimulation/recording system with bidirectional communication. The NIBIB and NICHD are funding this project.
Computation-Enabled Adaptive Ventilatory Control System (CENAVEX)
Thousands of people have a spinal cord injury that severely impairs or completely paralyzes the respiratory musculature. This project will develop a smart adaptive ventilatory control system that activates paralyzed muscles by a personalized electrical stimulation pattern that meets the ventilatory needs of the individual. It will overcome drawbacks of mechanical ventilation or prefixed stimulation by utilizing neuromorphic spiking neural networks. Supported by National Institute of Neurological Disorders and Stroke.
Biomechanical Patterns for Identifying Biomarkers in Knee Osteoarthritis
More than 20 million people in the U.S. suffer from knee osteoarthritis (OA). OA is a two-part, degenerative, chronic, and often progressive joint disease characterized by a repetitive inflammatory response of the articular cartilage. The result is a narrowing of the joint space which leads to pain, immobility, and often disability. In fact, a majority of people stricken with this disease report having some movement limitation, some report an inability to perform major activities of daily living, and some need personal care assistance. A better understanding of the biomechanical changes in knee extension and flexion movement presented by patients with knee OA is important to improve comprehension of the development of the disease, to establish a rehabilitative approach appropriate to each stage of the disease, and to determine the best time for knee replacement surgery. The aim of this study is to use electromyogram (EMG) to compare patterns of muscle activity between adults with OA and healthy adults in selected mobility tasks. Of specific interest are timing and amplitude of phasic muscle activity and neuromuscular efficiency. The long-term goal is to provide evidence-based support for development and use of the treatment protocols to be followed for knee OA subjects. This project is partially supported by funds from the Ministry of Science and Technology in India.
In the first year after incomplete spinal cord injury (iSCI), substantial improvements in sensorimotor function can occur. The pattern and extent of recovery, however, are highly variable and depend upon several factors, including the nature of injury, the intrinsic adaptive capabilities of the injured central nervous system, and the interventions applied. The injured CNS is capable of significant intrinsic adaptive responses at multiple levels within the motor control system. These complex processes are highly variable and poorly characterized. However, a key component of this recovery is likely to be the reorganization of the dynamic interaction between the supraspinal and spinal segmental circuitry for motor control of the musculoskeletal system. Neuroanatomical changes that occur after spinal injury include spinal axonal sprouting above and below the lesion and cortical remodeling.
After thoracic SCI the dendritic arbor of the spinal lumbar motoneurons in the spinal cord is reduced. Since dendrites play a crucial role in the integration of multiple inputs to a neuron, reduction in this arbor could have deleterious effects on the ability of the lumbar motoneurons to integrate the multiple supraspinal and spinal inputs. Passive rhythmic exercise can prevent degradation in the dendritic arbor of motoneurons below the injury site and restore motoneuronal properties. The goal of this project is to characterize the ability of FNS-assisted locomotor training to improve sensorimotor recovery in a rodent model of incomplete spinal cord contusion injury and examine the effects of such therapy on neuroanatomy and spinal reflex circuitry.
Sensory Perception and Motor Control in Adults
With more than 1 million individuals living with amputations in the United States, the development of advanced prostheses is imperative. However, adequate replacement of the human hand and arm remains problematic. In other projects, we developed an advanced prosthetic system that will be capable of providing sensory feedback to upper extremity amputees using sensors embedded in the prosthetic hand. To test how well the amputee is able to control the advanced prosthesis, we have developed a variety of measurement devices and sensorimotor assessment protocols and we have purchased a validated instrument (SHAP: Southampton Hand Assessment Procedure, a clinically validated hand function test developed to assess the effectiveness of upper limb prostheses). However, to characterize the benefits of the prosthetic system fully, we need to know the capabilities of able-bodied (control) subjects on the testing procedures that we have developed or adopted from the literature. Therefore, the goals of this research study are to investigate sensation, perception, and motor control in healthy adults.
Paired Associative Stimulation and Tactile Sensation
Clarifying the mechanisms by which the central nervous system and peripheral nerves communicate represents an area of active research that has led and will lead to clinical innovations. Transcranial magnetic stimulation (TMS) has been combined with peripheral nerve stimulation to generate paired associative stimulation (PAS), which is hypothesized to induce neuroplastic changes in the somatosensory cortex. PAS has been shown to induce changes in the cortex that are associated with increased 2-point discrimination at the fingertips. We wish to expand on this idea and examine whether PAS can enhance tactile discrimination of textures. If so, then therapies involving induced neuroplastic states could hasten recovery in those with tactile deficits (such as those who suffer from stroke, diabetes, or amputation).
Effect of Preksha Meditation in Students with and without Learning Disorders
Meditation has been shown to reduce stress and enhance performance of students in their studies. Other benefits of meditation include improvements in pulmonary function that result from associated breathing exercises. Despite these benefits, it is often difficult to add meditation to daily or weekly routines. In addition, much of the research on meditation has been conducted in non-disabled populations, and it is not clear whether meditation can offer the same benefits to those who are learning disabled, and whether the learning-disabled population has the same difficulty in keeping a regular meditation routine.
Mahapraan is a technique taught in Preksha Dhyan, as taught by Acharya Mahapragya. This technique involves deep breathing followed by a long buzzing sound. Preliminary results indicate that this type of meditation may improve attention shown in students with ADHD. The purpose of this study is to examine physiological (breathing parameters and EEG) and cognitive effects of meditation that is simpler and of a shorter duration than Preksha meditation. In addition, we will use a game application on a computer or smartphone to prompt students to meditate and to provide immediate feedback. In this way, we may assess whether this meditation helps students with and without learning disabilities. This information will open the door for potential future studies that examine the neurophysiological correlates of Preksha meditation. The study is acollaboration with the Religious Studies Department of FIU and is led by Samani Unnata Pragya.