These problems will emerge when experts want to make artificial limbs for amputees by imitating the natural functions of human hands. In the production process, we need to use a series of knowledge such as machinery, electronics and computer technology, and combine them skillfully. This interdisciplinary product is called mechatronics, which is the only feasible way to replicate human functions. Take making a prosthetic hand for a child, it must be small and powerful, easy to use and very energy-saving, because the prosthetic hand works on batteries.
A spring return mechanism used by British scientists has produced a kind of children's prosthesis that basically meets the above requirements. This kind of prosthesis is operated by a micro-motor driven by a single chip, which enables it to grasp objects. Children can stimulate hand movements by tightening the muscles on their arms, because when the muscles contract, they will be sensed by the EMG detector installed on their arms, thus generating low-voltage electrical signals. The greater the contraction, the stronger the signal. When the child relaxes the muscles, the spring will automatically close the claw catcher.
Because children's hands are small, the electronic equipment used for artificial limbs must be made very small, and in order to make the power consumption as small as possible, the static current should be very low. Semiconductor components are an ideal choice. As you can imagine, in the future design, software will inevitably become a key factor. Without software, computers are just machines, and artificial limbs commanded by computers are also machines.
Scientists at Stanford University in the United States have developed a new method, which uses nerve impulses to directly control the mechatronic prosthesis. Instead of using weak EMG signals that are easily disturbed by noise, they induce nerve endings to grow into special circuit chips with hundreds of holes. After the brain generates the signal, it is processed by the neural network circuit and then controls the actuator. However, patients who use this kind of prosthesis must first receive the training of physiotherapists and learn to make the neural network respond appropriately to special instructions. This method seems smarter than the previous one.
Prosthetics is an important part of medicine, and it will be good news for amputees to develop flexible prostheses. With the continuous progress of modern science and technology, one day people will make artificial limbs comparable to real limbs.