Design, development and implementation of neurologically controlled prosthetic limb capable of performing rotational movement

Abstract

Prosthetic limbs are commonly used by people with limb loss (acquired amputation) and limb absence (congenital deficiency) to restore or imbue some of the function and/or cosmesis of an anatomical limb. Prosthesis is part of the field of biomechatronics, the science of using mechanical devices with human muscle, skeleton, and nervous systems to assist or enhance motor control lost by trauma, disease, or defect. Ionomeric Polymer-Metal Composites (IPMC) are attractive type of electroactive polymer actuation materials because of their characteristics of large electrically induced bending, mechanical flexibility, low excitation voltage, low density, and ease of fabrication. The diffusion of ions between the electrodes causes the material to bend. IPMC material acts as the artificial muscle in prosthetic limb. Nerve signals obtained from the natural damaged muscle will be read and amplified so that the IPMC connected to the lost limb will work as per the characteristics of this signal. Electrodes will be attached between the patient limb and the microprocessor, which will analyze nerve signals to be processed and provide the appropriate output to the IPMC. Once nerve signals characteristics are read and reaction from the IPMC is achieved an arm chassis will be constructed. The advantages of IPMC in requiring low activation voltage and the induced large bending strain led to its consideration for various prosthetic applications. IPMC reacts to a changing voltage. When voltage is applied the material will bend, but if the voltage applied remains constant the material will slowly retract back to its neutral state. As the frequency of electrical impulses rises, so does the degree of fluctuation of the IPMC. Using this phenomenon of variation of degree of fluctuation with frequency of impulses, we can provide a 360 degree rotational arm by appropriately selecting the motor and impulse sequence. In major present prosthesis only vertical or horizontal movement of the prosthetic arm is possible. In this analysis, a rotational prosthetic arm using IPMC and controlled by nerve signal will be produced.