Transcarpal/metacarpal or partial hand disarticulation prosthesis, external power, self-suspended, inner socket with removable forearm section, electrodes and cables, two batteries, charger, myoelectric control of terminal device, excludes terminal device(s)
Electric hand, switch or myoelectric controlled, independently articulating digits, any grasp pattern or combination of grasp patterns, includes motor(s)
The problem is that the bone can—and often does—move around within the remaining soft tissue and hit the inside walls of the socket, causing pain and discomfort . . . and if that happens, it doesn’t matter how impressive that myoelectric prosthesis is, most of the time the disheartened amputee will give up and just won’t wear it!
The High Fidelity Imager captures the motion of the underlying bone so there is no lost motion. Think of a clapper inside of a bell. When a bell moves, seconds later the internal clapper strikes the inside wall of the bell making the sound. This is not the way we want a prosthesis to work. Amputees don’t want to move, then seconds later have their prosthesis follow. They want a solid, stable, instantaneous response from their prosthesis. They also do not want their bone smacking against the inside of their socket. With the High Fidelity Interface, there is a significant improvement in control, comfort level and energy consumption required to use the prosthesis.
In body-powered arms, there are cables which connect the limb to another part of your body. The cable may run from the prosthetic hand or pincher to your opposite shoulder. As you move your opposite shoulder in various ways, you can control the prosthetic.
In this policy, procedures are considered reconstructive when intended to address a significant variation from normal related to accidental injury, disease, trauma, treatment of a disease, or congenital defect, irrespective of whether a functional impairment is present. This reconstructive benefit may be applied in cases in which the myoelectric prosthesis is requested based on appearance. Not all benefit contracts include benefits for reconstructive services as defined by this policy. Benefit language supersedes this document.
The most recent technology in powering prosthetic limbs is myoelectric power. With these, the arms are powered by the muscles in your residual limb that can be contracted to generate electrical signals to move the limb. Electrodes are placed on the skin to read the muscle contractions and cause the limbs to move accordingly.
When using any of these ways to power a , it can take some time to get used to moving the limb. You need to figure out the right way to move to pull the cable, push the buttons and switches, or contract your muscles in order to make the arm work the way you want it to. At Human Technology Prosthetics & Orthotics in Memphis, we can work with you to help you practice with the limb and figure out how to use it.
The passive prostheses rely on manual repositioning, typically by moving with the opposite arm and cannot restore function. This unit is the lightest of the 3 prosthetic types and is thus generally the most comfortable.
Often, this will be through electromyography sensors, which register when the user flexes their muscles and operates the arm accordingly. Alternately, in targeted muscle reinvention, a doctor operates on the patient and rewires the nerves in another part of the body to operate the robotic limb. A third way to send signals is to surgically implant sensors to the amputated stump. All of these signal-sending methods can prove tricky. Users of most prosthetic limbs have to concentrate on their movements, and sometimes they are unable to do anything else while moving that limb.
When you think of a prosthesis, many people think of a fancy myoelectric arm or microprocessor controlled knee. It can be quite memorable to see a sleek myoelectric hand power up, move and grasp an item with lifelike intentionality. But in reality, it’s the parts you don’t see-the skeletal shape captured in the socket or interface-that are the most important in helping you move more comfortably and naturally. That’s because more intimately the socket interface can capture remaining skeletal movement, the better range of motion, energy efficiency, and comfort you’ll have with a prosthesis.
There is some good news, though. Recent years have seen many improvements in robotic prostheses thanks to technological improvements which utilize better materials, longer battery life, more efficient microprocessors. Fortunately, robotic and other areas are also becoming more cost effective as a result, and a larger number of people are able to afford them than ever before.
Myoelectric prostheses use muscle activity from the remaining limb for control of joint movement. Electromyographic (EMG) signals from the limb stump are detected by surface electrodes, amplified, and then processed by a controller to drive battery-powered motors that move the hand, wrist, or elbow. Although upper-arm movement may be slow and limited to 1 joint at a time, myoelectric control of movement may be considered the most physiologically natural.