Accelerometers from Smartphones can be used in Prosthetics

Accelerometer used for detecting the gravity and velocity changes enables a device to detect its orientation.

Prosthetics replaces lost limbs of person, but thes electrically powered prostheses are difficult to operate and cannot fully replace normal limbs.

Smart phone technology can be used to over come this disadvantage. Norwegian University of Science and Technology(NTNU)researchers  are working on this Smart phone technology in prosthetics.

Accelerometer in your smart phone helps it determine whether you want to look at a photograph in a portrait or ladscape format. A accelerometer is a tool for detecting changes in gravity  or velocity and enables a device to determine its orientation. Accelerometers are cheap when compared with the other prostheses.    

Oyvind Stardahl and Anders Fougner of NTNU, have proved that when an accelerometer is used can easily recognise how the arm is oriented in space. Prostheses are controlled by the remaining muscles in the servered limb. Prostheses may receive  signals from muscles and may lead to the prosthesis to perform wrong movement. For normal prosthetic function, orientation of the arm should be known.

The electrically powered prostheses took its origin in the 1940’s . they use the same technology that was used in 1940’s till date for prostheses of limbs. After that period there is a great advancement in technology but still the modern upper limb prostheses has a mechanical hand that can grasp, some arms include a rotating wrist.

An amputee operates his or her prostheses using his muscle. The muscle sends certain electrical signal to the electrodes placed on the surface of the skin. These electrodes detect these signals and converts them to movements using microporcessor and motor. Activation of specific group of muscles will lead to specific movements of prostheses such as closing and opening of hand , rotating the wrist. This needs a lot of practise. Amputee without practise may not be able to use this prostheses efficiently it may lead to wrong movements of the prostheses or crashing of the system. 

Example a person may not be able to lift a bucket from the ground when his limb is in a horizontal position. There has to be other functions performed for his prosthetic limb to come to vertical position.

All these disadvantages of the 1940’s prosthetics can be over come using the accelerometer used in smart phones. As the accelerometer has the capability to detect orientation of the objects.  The smart phone technology may improve the lives of the people . The accelerometer along with proper training can reduce the frequency of incorrect movements of prosthetic limbs.