Short-term Implanted Electrodes Following Regenerative Peripheral Nerve Surgery for Improving Prosthetic Limb Control Signals

Inclusion Criteria:

- Participants must be 22years of age or older.

- Participants must have previously undergone an upper limb amputation proximal to the
wrist.

- For participants without existing RPNI grafts (at the time of enrollment), the
residual limb must have sufficient soft tissue quality to support performance of the
RPNI operative 305 8procedures. Participants sustaining severe crushing or avulsion
injuries with substantial superficial and deep scarring may not be appropriate
candidates for inclusion in the study. °Participants must be in good health and
American Society of Anesthesiologists (ASA) Class I (low surgical risk).

- Participants must live within 2 hours of the University of Michigan Hospital.

- Participants must have reliable transportation.

- Participants must be able to attend at minimum 2 visits per month while electrodes
remain implanted.

- Participants must be at least 12 months post-amputation.

Exclusion Criteria:

- Participants may not be suffering from any severe pain syndrome including complex
regional pain syndrome or severe phantom pain. All of these conditions would suggest
pathological activity of the nerve and would exclude the participant from
participation.

- Participants must not be suffering from any untreated mental health disorders and if
they have any DSM-5 diagnoses, they must receive approval to participate from their
mental health professional.

- Participants must not have any medical conditions that, in the opinion of the
Principal Investigator, would place them at high risk for a surgical procedure
including recent myocardial infarction, cerebrovascular accidents, deep venous
thrombosis, pulmonary embolus, uncontrolled diabetes, or end stage renal disease.

- Participants must not have used tobacco for at least one month prior to enrollment in
the study.

- Participants must agree to not use tobacco for the duration of the study.

- Participants cannot have sustained bilateral upper extremity amputation.

- Participants cannot be pregnant.

- Participants must not have other indwelling electronic implants like pacemakers,
implantable cardioverter defibrillators, implantable neurostimulators, body worn
insulin pumps, or body worn patient monitoring devices.

- Participants must not have severe peripheral vascular occlusive disease, venous
hypertension of the extremity, or severe lymphedema of the extremity.

- Participants must not have an autoimmune condition which is not well controlled by
medication.

- Participants must not be older than 65 years of age.