Why is this study being done?
We are investigating the effectiveness of using Targeted Muscle Reinnervation (TMR) surgery and Pattern Recognition Control to enhance the use of multi-articulating prosthetic hands.
Targeted Muscle Reinnervation (TMR) is a surgical technique that transfers damaged nerves from the amputation site into the functioning nerves of a nearby muscle. Connecting the damaged nerves to the functioning nerves of a muscle allows them to grow into (reinnervate) the target muscle. TMR creates additional muscle control sites with the intention of making prosthesis control more intuitive and allowing more prosthetic functions.
Pattern Recognition Control is programming prosthesis with advanced computer algorithms that learn to recognize and distinguish your distinct muscle patterns. As the prosthesis learns your muscle patterns, you simply have to try and make the desired movement and the prosthesis will then respond with the correct movement.
Who is eligible to participate in this study?
In order to participate in this study, you must:
- Be 18 years or older.
- Be able to read and comprehend English.
- Have a below-elbow amputation.
- Be available for 6 visits over the course of 12 months.
- Have previous experience using a myoelectric prosthesis (preferred).
What is involved in the study?
The first step is setting up a phone call between prospective patients and one of our study coordinators to discuss past medical history and answer any questions about the trial you might have.
The next step is to set up an initial appointment at one of our study sites for an evaluation. A physician will review your medical history and determine if you’re a good candidate to join the study. If you qualify and agree to participate, we will review the consent form with you and upon signing it you will be officially enrolled in the study.
This study involves several multi-day visits to learn how to use the prosthesis. Some of these visits will be at one of our study sites, while other visits may take place at or near your home. Study coordinators will determine the best location.
Phase 1 – During the first phase of the study, a prosthetist will fit you with a custom-made socket and a multifunctional hand system. You will receive 1-3 days of training to learn how to control the prosthesis with “conventional control.” For conventional control, one electrode will be placed over your forearm flexors; another will be placed over your forearm extensors to control the prosthesis movement. You will then return home for an 8-week home-use trial where you will use the prosthesis for an average of 2 hours per day. Following the first 8-week home-use trial, you will be asked to complete a series of outcome tests with the hand system. Afterwards, we will change the control of the prosthesis to “pattern recognition control.” For “pattern recognition control,” a grid of 8 electrodes will be used to record your muscle activity. You will then complete another training session at one of the study sites to learn the new control method, followed by 8-weeks of home use, and a series of outcome tests to measure functionality.
Phase 2 – For Phase 2, you will return to one of the three study sites to receive Targeted Muscle Reinnervation (TMR) surgery.
Six months post-surgery, you will return to one of the study sites to be re-trained on “pattern recognition control” and then will repeat the 8-week home trial, and outcome tests to measure functionality. After the initial 8-week post-surgery test you will continue to use the multi-articulating hand prosthesis with “pattern recognition control” another three to four months.
All participants will test the prosthetic hand system pre-operatively using Conventional Control and Pattern Recognition and then post-operatively using Pattern Recognition.
Where is this trial occurring?
This study is funded by The National Institutes of Health (NIH) and is open to both civilians and military service members. There are currently three hospitals recruiting subjects for this study:
- Rehabilitation Institute of Chicago (RIC) / Northwestern Memorial Hospital (Chicago, Illinois) – Currently recruiting patients for study
- Walter Reed National Military Medical Center (Bethesda, Maryland / Washington, DC)* – Currently recruiting patients for study
- San Antonio Military Medical Center (San Antonio, Texas)* – Currently recruiting patients for study
*These sites are only available to active duty military, veterans, and other qualifying personnel