What's the difference between a myoelectric hand and an ordinary prosthesis?

We live in this world, and it is inevitable that we will encounter accidents. What should we do if we lose our limbs in the accident and become disabled? Of course, we can see that some people with broken legs installed artificial legs to support their bodies, and those with broken arms installed artificial arms for decoration, but these things do not have the basic functions of real legs and hands. With the development of science and technology, people began to gradually abandon artificial limbs made of wood or other products and replace them with electronic artificial limbs. Electronic prosthesis can complete seven or eight movements according to the consciousness of the brain, which is close to the function of real limbs.

The human body is a charged body, and various parts of the human body will generate bioelectric current when they move. Then, brain thinking will naturally produce EEG signals. If this electrical signal commands the limb to move, it will stimulate the motor nerve, and the motor nerve will transmit the command current to the limb muscles, so that the muscles will generate corresponding EMG signals, so that the limb can be controlled to take, release, extend and contract by the EMG current. After the limb is broken, the brain's thinking can still send out action instruction current. Scientists have found that when the real hand is moving, the muscle current in the upper part of the human body is circulating, which controls the movement of the real hand. Based on this discovery, they decided to take out the current from the spine and chest to control the limb movement, and use it as the power to operate the myoelectric hand composed of micro-motor, lever and microprocessor.

This myoelectric hand has seven micro motors, five from shoulders to elbows and two from wrists and fingers. The current drawn from the spine and chest is processed by microprocessor, amplified by 100 times and transmitted to the micromotor. The micromotor drives the lever to act, and its action form corresponds to the control current. At present, this myoelectric hand can complete 7 ~ 8 basic movements, lifting 1 kg. With the further development of science and technology, the development of myoelectric hand is more perfect, which can generate "feeling" current and feed it back to the human brain. In this way, it can not only be controlled by the brain, but also have the same "nerve feeling" as the real hand, and complete 27 complex skills that a real hand can undertake.