Clinical Trial: Feasibility of Implantable Myoelectric Sensors to Control Upper Limb Prostheses

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Feasibility Study to Assess Safety and Functionality of Implantable Myoelectric Sensors for Upper Extremity Prosthetic Control in Transradial Amputees

Brief Summary: This study will evaluate the feasibility of using implanted myoelectric sensors (IMES) to control an electromechanical prosthetic wrist and hand.

Detailed Summary:

The study assesses the feasibility of an advanced prosthesis control system aimed at development of a more intuitive and functional prosthetic device. Tiny (2.5 mm by 16 mm) Implantable Myoelectric Sensors (IMES) will be implanted into the residual forearm muscles of three transradial amputee subjects. These devices wirelessly transmit electrical muscle signals to an electromechanical prosthetic wrist and hand.

Following a two-week recovery from implantation of six to eight IMES into residual forearm muscles, subjects will initiate seven months of training. Subjects first train for approximately a month using a bench-top IMES system. When they receive their custom-fit IMES Prosthesis (including electromechanical wrist and hand) subjects initiate six months of additional training. Subjects will then be given the option to use the IMES Prosthesis for another sixteen months. The usability and functionality of the prosthetic system will be evaluated throughout the study.

Current Primary Outcome:

• Device-Related Serious Adverse Events [ Time Frame: Information collected over the course of 2 years following implant of IMES ]
  Tabulation of Device-Related Serious Adverse Events during the course of the study.
• Change in Accuracy Test score [ Time Frame: test conducted nine times: upon receipt and programming of custom-fit IMES prosthesis; once per month for six months of training; 1 year following implant; and 2 years following implant ]

  The Accuracy Test requires subjects to execute a series of different hand movements using the IMES to control an electromechanical wrist and hand. Movements are chosen to demonstrate both independent and simultaneous control over the six different movements offered by the prosthesis: hand open/close, thumb adduct/abduct, wrist supinate/pronate. An occupation therapist will score the subject on each movement as follows: 0 = no movement observed; 1 = the intended movement was not observed, but unintended movements were observed; 2 = the intended movement was observed, in addition to unintended movements; 3 = the intended movement was observed. The change in Accuracy Scores across the nine tests completed will be presented.

  During the Accuracy Test, Electromyographic(EMG) signals transmitted by the IMES will be recorded. A video camera will record the movements of the prosthesis so that this output may be associated with the input IMES signals.

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Change in Southampton Hand Assessment Procedure (SHAP) test score [ Time Frame: test conducted nine times: upon receipt and programming of custom-fit IMES prosthesis; once per month for six months of training; 1 year following implant; and 2 years following implant ]
  The test entails a series of self-timed tasks (the participant starting and stopping the timer with the hand under test), which are divided into two sections: picking and placing eight different shaped objects and performing fourteen Activities of Daily Living (ADL). The objects are shaped to encourage the use of six standard prehensile patterns (spherical, tripod, power, lateral, tip, extension) and come in two different weights to test the participant's ability to form more powerful grips. The fourteen simulated ADLs include cutting, pouring, lifting and transferring loads. Subjects will perform the SHAP test using the IMES to control an electromechanical wrist and hand. Each task is scored based on the amount of time to complete. The change in SHAP scores across the nine tests completed will be presented.
• Change in Assessment of Capacity for Myoelectric Control (ACMC) test score [ Time Frame: test conducted nine times: upon receipt and programming of custom-fit IMES prosthesis; once per month for six months of training; 1 year following implant; and 2 years following implant ]
  The ACMC is administered and scored based on observations of the subject as he or she is performing an everyday task using the IMES to control an electromechanical wrist and hand. Tasks will be chosen from a selection of six that include: packing a suitcase, sorting mail, mixing a ready-to-eat product, repotting a plant, assembling a ready-made project, and setting a table. During the assessment, subjects are encouraged to accomplish the task spontaneously in their usual way. The occupational therapist assesses capacity for control of the prosthesis by rating the performances on 22 items representing different aspects of control that are classified as gripping, holding, releasing, and coordinating between hands. Each subject's performance is rated with scores ranging from 0 to 3, where 0 = not capable, 1 = sometimes capable, capacity not established, 2 = capable on request, and 3 = spontaneously capable. The change in ACMC Scores across the nine tests completed will be presented.
• Change in Box and Block Test (BBT) score [ Time Frame: test conducted nine times: upon receipt and programming of custom-fit IMES prosthesis; once per month for six months of training; 1 year following implant; and 2 years following implant ]
  The BBT measures unilateral gross manual dexterity. The BBT is composed of a wooden box divided in two compartments and 150 blocks. The subject is asked to move as many blocks as possible from one compartment of a box to another, within 60 seconds. The task is to be performed using the IMES to control an electromechanical wrist and hand. The change in BBT Score across the nine tests completed will be presented.
• IMES Satisfaction Questionnaire [ Time Frame: completed after six months of training following upon receipt and programming of custom-fit IMES prosthesis ]
  Subjects will be asked to complete a questionnaire in which they rate and describe their satisfaction with different aspects of the IMES Prosthesis.

Original Secondary Outcome: Same as current

Information By: The Alfred E. Mann Foundation for Scientific Research

Dates:
Date Received: May 20, 2013
Date Started: May 2013
Date Completion:
Last Updated: February 27, 2017
Last Verified: February 2017