Restoring Function with Bionic Limbs

Bionics has undergone giant leaps in technology and plays an important role in changing the functionality of the disabled. The hardware design of Bionics is a truly remarkable aspect with the computerized limbs reproducing the real movements precisely. The Brain Machine Interfaces (BMI's) used in the Bionic limbs is an innovative technology that makes the limbs more effective and perform various functions flexibly.

The different functions performed by our body are as a result of electrical impulses transmitted from the motor cortex present in the brain. The impulses travel from the brain through the spinal cord in the nerves and are then passed on to the muscles. This activates the muscles and causes movement like raising our hands, walking, running and various other limbic movements done by us every day. The simulation of this mechanism by the Brain Machine Interface is the main technology that propels Bionics.

There are two types of BMI's namely non-invasive and invasive types. The EEG is a type of non invasive BMI. The electroencephalograph (EEG) gives the measurement of the neuron groups by gauging the difference in voltage, in the different parts of the brain. Electrodes are placed on strategic points in the scalp and the signals that are emitted, are changed to digital format and processed in a computer. With the help of an EEG, a severely compromised tetraplegic was able to use his paralyzed limb to grasp an object. The EEG facilitated recognition of the brain waves of the patient and changed them into electrical stimuli, which was then able to elicit the muscular movement.

Invasive type of Brain Machine Interface helps in achieving almost hundred percent normal movements, in patients who have serious spinal cord damage and also in case of amputee patients who have bionic limbs fitted to them. The invasive type is fixed inside the brain directly and due to the close contact with the motor cortex there is an accurate measurement of electrical signals.

The first man to be attached with a bionic limb was a 53 year old electrician named Jesse Sullivan. This was accomplished in the year 2000. The nerves responsible for transmitting signals to his hand were repositioned in his chest and electrodes were fitted to record the signals and convert them, with the help of the computer, to digital signals that control the bionic limbs. View Video.

Further research is being done with the bionic limbs to enable them to function more effectively with added abilities like making them 'feel', send information to the brain and be sensitive to hot or cold substances and also to applied pressure.

In addition to the restoration of movement using bionic limbs, studies are being made on enabling sight and hearing in the blind and deaf people. In case of loss of eyesight, an electronic chip implanted in the retina is programmed to send signals, when stimulated by the signals received from a camera fixed to eye glasses. In case of hearing impaired patients, small wires are placed in the cochlea and a microphone is placed in the skull. These help in restoring the hearing.

With all the new advancements that are taking place in the field of Bionics, disabled people are becoming more and more enabled to do the normal functions, in spite of deformity or loss of function to their body parts.

source: The Bionic Woman: Complete Episode Guide by Gregory M Branson-Trent