Amputation
Conditions
Brief summary
The overall goal of this project is to develop a virtual neuroprosthesis in which a facsimile of a neural implant is externalized and housed in a well-controlled microfluidic chamber, thereby abating the intrinsic limitations of highly invasive studies with neural implants. Able-bodied and upper limb amputee subjects will be recruited to control a dexterous artificial hand and arm with electromyogram signals while electroencephalogram (EEG) signals are simultaneously measured. Robotic grip force measurements will be biomimetically converted into electrical pulses similar to those found in the peripheral nervous system to catalyze in vitro nerve regeneration after neurotrauma. The synergistic contributions of this multidisciplinary project will lead to a transformative understanding of the symbiotic interaction of neural plasticity within human-robotic systems. Currently, there is no systematic understanding of how tactile feedback signals can contribute to the neural regeneration of afferent neural pathways to restore somatosensation and improve motor function in amputees fitted with neuroprosthetic limbs. Tackling this problem will be a significant breakthrough for the important field of neuroprosthetics.
Detailed description
Over one week, neurobehavioral processes will be examined in people controlling a robotic arm and hand to perform simple motor tasks (e.g. fragile object transportation), while a virtual peripheral nerve regeneration protocol provides users with biologically-realistic, idiosyncratic parameters for the restoration of haptic sensation (in double-blind fashion, the cellular neurophysiologists characterizing neural regeneration with microscopy are unaware of subjects' name and condition; and the human-subject experimenters are unaware of the haptic feedback parameter that will be used in the experiment each day, which is entered by the neurophysiologist in a black-box section of the software in the case of microscopic evaluation of nerve regeneration (early part of the project), or which is automatically input by the system in the case of real time impedimetric measurements (later part of the project)). The main experimental factors are 'haptic feedback', with three modalities: full, partial (nerve-regeneration dependent) and null; and to challenge human control strategy and impose demand on haptic information, the 'transported object weight' (heavy, medium and lightweight). Recording techniques: Subjects' electroencephalography (EEG), electromyography (EMG) and behavioral performance.
Interventions
BEHAVIORALSensory Restoration During Prosthesis Control
Human subjects who use a robotic arm/hand interface will experience variable sensations of touch over time.
Sponsors
University of Utah
National Institute for Biomedical Imaging and Bioengineering (NIBIB)
Florida Atlantic University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Study falls under device feasibility: An intervention of a device product is being evaluated in a small clinical trial to determine the feasibility of the product; or a clinical trial to test a prototype device for feasibility and not health outcomes. Such studies are conducted to confirm the design and operating specifications of a device before beginning a full clinical trial.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* No neurological impairment of tactile sensation.
Exclusion criteria
* Younger than 18 or older than 65
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Artificial Hand Grasp Performance Metrics | 1 week | The percentage that grasped objects are successfully transported without slip or drop when controlled by amputees using an artificial hand. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Dorsal Root Ganglia Neurite Regeneration | 1 week | The length of neurite regeneration 1 week post-axotomy will be quantified. The dorsal root ganglia will be cultured in vitro in a multichannel microelectrode array. The neural culture will be electrically stimulated based on the touch sensations from the artificial hand that is used by amputees. The fingertip touch sensations will be biomimetically converted into pulses that resemble action potentials for the electrical stimulation. The length of neurite regeneration was quantified using NeuronJ to compare images at the beginning and endpoints of the study. |
Countries
United States
Participant flow
Pre-assignment details
Exclusion criteria preventing subjects from participating are an amputation wound that has not yet healed, the absence of a suitable length of residual limb for placement of haptic feedback controller and EMG sensors, presence of pain that prevents utilization of those experimental appliances and the use of psychoactive drugs that modifies baseline neural activity.
Participants by arm
| Arm | Count |
|---|---|
| Nerve Growth During Prosthesis Control Determine the optimum conditions that promote sensory restoration in limb-absent people, with an adaptive haptic feedback control law that mimics the experience of neural plasticity.
The intervention Sensory Restoration During Prosthesis Control will be used.
Sensory Restoration During Prosthesis Control: Human subjects who use a robotic arm/hand interface will experience variable sensations of touch over time. | 21 |
| Total | 21 |
Baseline characteristics
| Characteristic | Nerve Growth During Prosthesis Control |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 21 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 2 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 3 Participants |
| Race (NIH/OMB) White | 15 Participants |
| Region of Enrollment United States | 21 Participants |
| Sex: Female, Male Female | 7 Participants |
| Sex: Female, Male Male | 14 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 21 |
| other Total, other adverse events | 0 / 21 |
| serious Total, serious adverse events | 0 / 21 |
Outcome results
Primary
Artificial Hand Grasp Performance Metrics
The percentage that grasped objects are successfully transported without slip or drop when controlled by amputees using an artificial hand.
Time frame: 1 week
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Experimental: Nerve Growth During Prosthesis Control | Artificial Hand Grasp Performance Metrics | 90.6 percentage of successful transportation | Standard Deviation 14 |
Secondary
Dorsal Root Ganglia Neurite Regeneration
The length of neurite regeneration 1 week post-axotomy will be quantified. The dorsal root ganglia will be cultured in vitro in a multichannel microelectrode array. The neural culture will be electrically stimulated based on the touch sensations from the artificial hand that is used by amputees. The fingertip touch sensations will be biomimetically converted into pulses that resemble action potentials for the electrical stimulation. The length of neurite regeneration was quantified using NeuronJ to compare images at the beginning and endpoints of the study.
Time frame: 1 week
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Experimental: Nerve Growth During Prosthesis Control | Dorsal Root Ganglia Neurite Regeneration | 2309 micrometer | Standard Deviation 222 |