Inclusion Criteria:
1. Subjects must have a unilateral transradial amputation or wrist disarticulation.
2. Subjects must demonstrate independent voluntary control of muscles in the flexor and extensor compartments of the forearm
3. Subjects must be over 1-year post-amputation at time of implantation.
4. Subjects must be between the ages of 22 and 70 years old. Subjects outside this age range may be at an increased surgical risk and increased risk of fatigue during prosthetic training.
5. Subjects must be able to communicate with the investigators in English because of the need to follow the instructions of the study team.
6. Subjects must show an understanding of the study goals and have the ability to follow simple directions as judged by the investigators.
7. Subjects must pass a neuropsychological and psychosocial assessment.
8. Documentation of informed consent must be obtained from the subject.
Exclusion Criteria:
1. Subjects must be able to function without the use of a prosthesis, or have access to assistance, for a period of 6 weeks following implantation and explantation surgeries.
2. Subjects must not have visual impairment such that extended viewing of a computer monitor would be difficult even with ordinary corrective lenses.
3. Subjects who have another serious disease(s) or disorder(s) that could affect their ability to participate in this study (verified during pre-op anesthesia evaluation to determine surgical risk status) will be excluded.
4. Subjects must not have phantom limb pain that is self-reported to be severe (options are no pain, mild pain, moderate pain, severe pain).
5. Subjects must not have any type of implantable generator such as a pacemaker, spinal cord stimulator, cochlear implant, deep brain stimulator (DBS) or DBS leads, vagus nerve stimulator, or defibrillator.
6. Female subjects of childbearing age must not be pregnant, lactating, or plan to become pregnant during the next 25 months.
7. Subjects must have no history of peripheral vascular disease that could impact wound healing.
8. Subjects who require routine MRI, therapeutic ultrasound, or diathermy as part of their ongoing care will be excluded.
9. Subjects must not have osteomyelitis.
10. Subjects must have no history of intractable clinically relevant cardiac arrhythmias.
11. Subjects must have no active infection(s) or unexplained fever(s) (verified during pre-op anesthesia evaluation to determine surgical risk status).
12. Subject must have no history of ongoing untreated alcoholism.
13. Subject must not be receiving chronic oral or intravenous steroids or immunosuppressive therapy.
14. Subjects must not be receiving medications that affect blood coagulation.
15. Subjects must not have had active cancer within the past year (other than adequately treated basal cell or squamous cell skin cancer) or require chemotherapy.
16. Subjects must not have uncontrolled insulin dependent diabetes mellitus.
17. Subjects who have had a seizure in the last two years will be excluded.
18. Subjects who have attempted suicide in the past 12 months will be excluded.
19. Subjects who are immunosuppressed or who have conditions that typically result in immunocompromise (including, but not limited to: ataxia-telangiectasia, cancer, Chediak-Higashi syndrome, combined immunodeficiency disease, complement deficiencies, DiGeorge syndrome, HIV/AIDS, hypogammaglobulinemia, Job syndrome, leukocyte adhesion defects, malnutrition, panhypogammaglobulinemia, Bruton disease, congenital agammaglobulinemia, selective deficiency of IgA and Wiscott-Aldrich syndrome) will be excluded.
20. Subjects with active psychiatric concerns, including but not limited to major depression, bipolar disorder, schizophrenia or other psychotic disorder and post-traumatic stress disorder. Individuals undergoing effective treatment for any of these disorders will not be excluded, but will be evaluated by a rehabilitation psychologist.
21. Subjects who report use of controlled, non-prescribed substances other than cannabis/marijuana will be excluded. If a subject reports use of cannabis, we will use the DAST-10 questionnaire to screen for level of abuse. An individual may be included if the score is 5 or less and if the neuropsychologist deems that they are eligible. Subjects reporting use of cannabis will also undergo a urine drug test to screen for other nonprescribed drugs. Subjects will be excluded if they test positive for any non-prescribed substance other than cannabis.
