Abstract:
The human arm is certainly the most powerful tool a human being has. It is
utilized in every task a human performs, from simple tasks like getting up or
sitting on a chair to extreme sports like mountain climbing or squash and tennis.
The absence of this tool due to any number of reasons can be very disturbing for
the amputee and this disability can be mentally and physically torturing. So the
modern science is doing its level best to create artificial limbs that can replace the
natural arm.
As the human arm consists of three separate joints, namely the wrist,
elbow and shoulder joint, the amputation can also be of different types, like above
elbow, below elbow or complete arm amputation from the shoulder joint. This
requires that separate prosthetic joints should be available that can be easily
attached either to the human user or can be attached to each other to form a
complete prosthetic arm.
The purpose of this thesis was to create a prosthetic wrist joint that can
behave like a human wrist and can be easily carried by a human user. So a 2-DOF
powered prosthetic wrist actuator has been proposed that can provide the
Abduction/Adduction & Flexion/Extension movements of the human wrist. The
basic structure of the actuator is a Ball & Socket joint and the force is transmitted
from the DC geared servo motors to the joint through the Bowden cables. The
proposed design is capable of providing the required degrees of rotation in both
axes i.e. 85° & 90° in flexion extension axis. The size and weight of the actuator
lies within the ranges of an average human being’s wrist.
