MYO Electric Prosthetic Limb
Arbab Shahid,Abdul Mannan ,Ali Zahab, HamzaAzam,Umar Shahbaz &Javeid Iqbal National University of Science & Technogy (NUST) College of E&ME. Rawalpini Pakistan Abstract: Prosthesis is an synthetic device that substitutes a missing body part. When a limb has been amputated, the motor and sensory nerves that used to serve it are still purposeful up to the point of amputation. If an interface can be made between these nerves and man-made electrical components, then the control signals that come from the brain to the limb could be used to control a mechanical auxiliary for the missing limb. The process uses active electrodes to get the signal from the muscles. Active electrodes contain a high input impedance electronics amplifier in the same housing as the detection surfaces. The amplifier used processes it to be measured using a Pico scope and interfaced on the computer. The voltage signal would be amplified and handled by the help of ADS-1298. This IC is fundamentally an ADC (24-bit) that processes the signal. The signal output from the ADC is then used to drive the motor.
Key words: EMG (Electro MYO Graph)
Prosthesis is an emerging field of bio-mechatronics which replaces the missing body part, lost during trauma or accident, using an artificial limb. It uses either the muscles or movement of the body parts to drive or assist motor control . The key purpose of a prosthetic limb is to mimic the appearance and to replace the functionality of the missing hand. The beauty of the project is in creating a balance in managing the cosmetic appearance and functionality of the arm. As such, there is a wide spectrum of specialized prosthetics that range from the purely cosmetic (which are inert) to the primarily functional (whose appearance is obviously mechanical). The MYO Electric prosthetic limb is the technology which practically blends both the requirements of the prosthesis. It does not compromise any of the requirements and is the future of the prosthesis . There are two main camps in the prosthesis functionality. The first one is body powered which uses the movement of the Arm or shoulder using a cable or harness to drive the artificial prosthesis. It has got only one advantage over the MYO ELECTRIC limb that is low cost and easy mechanical design. This has been established studying the previous designs and work done by the students previously working on the project in the department. The MYO electric limb uses EMG sensors along with an electrical system for control to drive the motor and a battery to power the limb. This avoids the physical exhaustion that the patient goes through in the mechanical arm. Even after the arm has been amputated, the nerves in the muscles are either fully functional or partially functional and if an interface can be achieved using an EMG electrode the signals from the brain can be used to control the motor driving the artificial limb. The user can even control the strength and speed of the limb’s movements and grip by varying his or her muscle intensity. A proper threshold can be attained using some training and rehearsal. Moreover, the acute sensors and motorized controls enable greater dexterity. The main advantage of this limb is that it functions almost exactly as the real limb using stimulus from the brain and does not require any straps or wires to function . The working of MYO Electric Prosthesis is simple: once it is attached, the prosthetic uses electronic sensors to detect minute muscle, nerve, and EMG activity. It then translates this muscle activity (as triggered by the user) into information that its electric motors use to control the artificial limb’s movements. Signal acquisition, one of the main aspects of this limb, is done using surface mounted EMG electrodes. The functionality and usage of these sensors is very simple: it captures electrical signals generated in the nerves using surface...
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