You might have seen the TERMINATOR movie series….and wondered how a robot senses everything around it and acts accordingly……then here’s the answer for your question….The BIONIC ARM
The “bionic arm” technology is possible primarily because of two facts of amputation. First, the motor cortex in the brain (the area that controls voluntary muscle movements) is still sending out control signals even if certain voluntary muscles are no longer available for control; and second, when doctors amputate a limb, they don’t remove all of the nerves that once carried signals to that limb. So if a person’s arm is gone, there are working nerve stubs that end in the shoulder and simply have nowhere to send their information. If those nerve endings can be redirected to a working muscle group, then when a person thinks “grab handle with hand,” and the brain sends out the corresponding signals to the nerves that should communicate with the hand, those signals end up at the working muscle group instead of at the dead end of the shoulder.
Surgeons basically dissect the shoulder to access the nerve endings that control the movements of arm joints like the elbow, wrist and hand. Then, without damaging the nerves, they redirect the endings to a working muscle group.
To use those signals to control the bionic arm, the RIC setup places electrodes on the surface of the chest muscles. Each electrode controls one of the six motors that move the prosthetic arm’s joints. When a person thinks “open hand,” the brain sends the “open hand” signal to the appropriate nerve, now located in the chest. When the nerve ending receives the signal, the chest muscle it’s connected to contracts. When the “open hand” chest muscle contracts, the electrode on that muscle detects the activation and tells the motor controlling the bionic hand to open. And since each nerve ending is integrated into a different piece of chest muscle, a person wearing the bionic arm can move all six motors simultaneously, resulting in a pretty natural range of motions for the prosthesis.
Courtesy : howstuffworks.com
Mahesh (3/4 ECE) MGIT
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