DExterous Hand Control Through Fascicular Targeting (DEFT) - (Human Subjects)

Criteria for Inclusion of Subjects: Hand, forearm and arm amputees: 1. Male or female, age 18 and older, of any race or ethnicity 2. Able and willing to sign Consent 3. Able and willing to participate in all study activities including implantation, testing and explantation of the study device. 4. Able to communicate effectively in English without an interpreter After preliminary screening subjects will be assessed for the following inclusion criteria: Overall and phantom pain are well-controlled and not incapacitating Criteria for Exclusion of Subjects: 1. If MR neurogram and EMG/NCS study show nerve or muscle dysfunction/injury at a higher level than anticipated based on the appearance of the physical amputation stump, the subject may be excluded from the study due to adverse neuromuscular anatomy which would preclude use of the proposed experimental electrode implants. The radiographs will be used to confirm suitability of the amputation stump configuration. If the bony anatomy of the amputation stump is found to be unsuitable, the patient may be excluded from the study. 2. Subjects who have a history of cardiac arrhythmia will be excluded from the study.