Prosthetic Arms

Unfortunately, with increasing industrialization and an increasing of daily accidents many people in the world got injured and losing their hands or part of a hand. after losing hand humans have only one choice. that is using a prosthetic arm. we can classify the prosthetic as per amputation into 5 categories.

1. Shoulder disarticulation — From Shoulder
2. Elbow disarticulation — Below Elbow — Above Elbow.
3. Wrist disarticulation — Below Elbow
4. Trans carpal disarticulation — Below Elbow
5. Finger amputations — Below Elbow

There are many types of prosthetic arms in the market some of them are just a structure of the human hand with no moving parts, they are called passive prosthetic arms. some of them are having mechanical or electrical moving parts that give more ability to the patient they are called active prosthetic arms.

Cosmetic Prosthesis

The cosmetic prosthesis is a passive prosthetic arm type which means cosmetic prosthesis is just a structure of a human hand made by cosmetic. But it can be used to hold or grip some objects. since it doesn’t have a complex mechanism inside the hand, it can be made very similar to actual human hands.

Body Powered Prosthesis

These are the prosthesis which is actuated using a cable attached to a harness that secures

prosthesis on the patient’s body. Giving a force to that cable, the patient can move the prosthesis. we can categories these types of arms as active arms but the mechanism for moving is not electronic.

Myo Electric Prosthesis

This is a type of active prosthesis arm that is very popular among researchers and engineers. It uses the electrical action potential of the residual limb’s muscles that are emitted during the contraction of the muscles. using those electrical pulses controller circuit in hand instantly move the relevant parts.

Those electronic emissions are microvolt level and vary from 10microvolt to 1milivolt. those emissions are detected by placing 3 electrodes in the patient’s skin. those signals are in a few Hz to 300Hz frequency range.amplifying above mention signals controller of the bionic arm can control the bionic arm according to the patient’s limb’s muscle movements.

References

Research Paper :“Mechanism and Control of a Prosthetic Arm”

by Tushar Kulkarni & Rashmi Uddanwadiker