An interventional study of a bipolar percutaneous intramuscular electromyography electrode in Amputation Neuroma and Amputation, sponsored by University of Michigan. Recruiting at 1 site in United States. Open to participants aged 22 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-08-18.
Sponsored by University of Michigan · Not applicable, Interventional, and Device feasibility
The device, a bipolar percutaneous intramuscular electromyography electrode, is intended for use in upper-limb amputation patients who have received the regenerative peripheral nerve interface surgical procedure, in order to enable the use of advanced prosthetic arms and hands.
This is a single center, 10 subject early feasibility study in which the primary objective is to ensure the safety of percutaneous intramuscular electrodes implanted in surgically-created RPNI constructs in subjects with upper limb amputation. This will be assessed with endpoints measuring participant pain levels, RPNI graft tissue health, electrode migration, and unanticipated adverse events associated with medium-term electrode implantation. The secondary objectives are to assess the efficacy of the electrodes in recording electromyographic signals from the RPNI grafts and in delivering electrical stimulation to the RPNI grafts to evoke sensory percepts. These will be assessed with endpoints measuring the signal quality of the recorded signals and the stimulation thresholds required to evoke sensory percepts.
This study will enroll people who have had upper limb amputations or are planning to have upper limb amputations. Each participant who does not already have RPNI grafts at the time of enrollment will have RPNI grafts implanted on branches or fascicles of nerves of the upper extremity. Several or all RPNI grafts will have a single bipolar electrode implanted in the muscle tissue, with the proximal end tunneled to a percutaneous exit point on the residual limb. Additional electrodes may be placed in innervated muscles in the residual limb, in order to provide a control comparison as well as to provide additional input during prosthesis control experiments. Electrodes will remain implanted for up to 10 years, with a minimum of 2 study visits per month to perform prosthesis control and sensory feedback experiments. Study endpoint will be assessed at a minimum of once per month while electrodes remain implanted. After a maximum of 10 years, electrodes will be explanted and the study ended after a 1 week follow-up.
The results of this study will inform the final design of the electrodes to be implanted long-term in RPNI grafts to provide an increased number of degrees of freedom for prosthetic control and sensory and proprioceptive feedback. This will drastically improve the functionality of the prosthesis, enhance the sense of embodiment of the prosthesis itself, and enable future investigation of a fully-implanted (non-percutaneous) prosthesis control system.
55 studies on the registry are indexed under Neuroma; 10 are open to participants now.
This study's planned enrollment of 10 is below the median of 34 across 36 interventional studies indexed under Neuroma.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
In this arm, participants will have an initial surgery to place partial muscle grafts on the amputated nerves. After a healing period, the participant will have a shorter surgical procedure to implant the electrodes onto the muscle grafts and in residual muscles. After another healing period, experiments with prosthetic control and sensory feedback will begin.
Device: a bipolar percutaneous intramuscular electromyography electrode
In this arm, participants have already had partial muscle grafts placed on the amputated nerves to control neuroma growth. The participant will have a short surgical procedure to implant the electrodes onto the muscle grafts and in residual muscles. After a healing period, experiments with prosthetic control and sensory feedback will begin.
Device: a bipolar percutaneous intramuscular electromyography electrode
The device, a bipolar percutaneous intramuscular electromyography electrode, is intended for use in upper-limb amputation patients who have received the regenerative peripheral nerve interface surgical procedure, in order to enable the use of advanced prosthetic arms and hands.
Change in Pain Level as measured by SF-36
Pain will be assessed using the SF-36 survey instrument, to be filled out by the participant before and after each surgical procedure performed and at a minimum of once per month while electrodes remain implanted. Two questions related to pain with a score closer to 0 means a pain increase
Time frame: Baseline and monthly for up to 10 years postoperatively
Change in Pain Level as measured by LANSS survey
Pain will be assessed using the LANSS survey instrument, to be filled out by the participant before and after each surgical procedure performed and at a minimum of once per month while electrodes remain implanted. A score greater than 12 indicates neuropathic pain.
Time frame: Baseline and monthly for up to 10 years postoperatively
Change in Pain Level as measured by Phantom Limb Questionnaire
Phantom pain will be assessed using the Phantom Limb Questionnaire, to be filled out by the participant before and after each surgical procedure performed and at a minimum of once per month while electrodes remain implanted. This 9-item instrument measures phantom pain on a scale of 0-4, where 0-no pain at all and 4=very severe pain.
Time frame: Baseline and monthly for up to 10 years postoperatively
RPNI tissue degeneration measured by pain scores
RPNI tissue degeneration will be assessed by changes in pain scores (see above) and measurements of recording efficacy. Recording efficacy will be assessed using two signal quality measures: 1. Peak-to-peak signal amplitude during maximum voluntary contraction 2. Signal-to-noise ratio during maximum voluntary contraction
Time frame: Baseline and once per month after surgery following a 3-month postoperative recovery period, while electrodes remain implanted.
RPNI electrode migration assessed by changes recording in efficacy and ultrasound
Electrode migration outside of the implanted RPNI graft or muscle will be assessed by changes in recording efficacy, as described above, and by ultrasound examination as necessary. Electrode extrusion and implantation complications will be assessed by adverse events reported by both the participant and the study physicians. At each study visit, the participant will be asked to report any issues, and will have a basic examination of the affected limb performed by study physicians and/or trained staff.
Time frame: Baseline and once per month after surgery following a 3-month postoperative recovery period, while electrodes remain implanted.
EMG signal quality from RPNI grafts
Efficacy will be assessed, for each implanted electrode using two calculated signal quality measures: Peak-to-peak signal amplitude during maximum voluntary contraction and signal-to-noise ratio during maximum voluntary contraction.
Time frame: Baseline and monthly for up to 10 years postoperatively
Stimulation Threshold of RPNI grafts
Stimulation data will be recorded at least once per month while electrodes remain implanted. Stimulation threshold will be determined using the range of sensory feedback necessary to evoke a sensory percept.
Time frame: Baseline and monthly for up to 10 years postoperatively
Plan to share: No
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