(Reissuing DR 25)

Chandigarh, July 13 (UNI) A novel, low-cost robotic arm with special sensors, brings a ray of hope for scores of war, terror and accident victims who have lost their limbs and for whom simple actions like drinking a cup of tea has turned into an uphill task.

The Myoelectric Arm, which resembles and performs like a natural arm, has been developed, for the first time in the country, by the Central Scientific Instruments Organisation (CSIO) here.

When introduced commercially, the electromechanical arm (robotic arm) is expected to cost Rs 20,000, which is just a fraction of a similar imported version which costs a whopping eight to nine lakh and is beyond the reach of most patients.

''The patient was able to perform many mechanical activities with this prosthetic arm like drinking water, writing with a pen, plucking flowers, picking and placing of objects from one place to another. The prototype has shown excellent results when tried at the patients at the National Institute for Orthopaedically Handicapped (NIOH), Kolkata,'' CSIO director Dr Pawan Kapur told UNI.

Myoelectric arm is nearest to the normal human arm. Here the muscle signals from the residual limb (stump) are picked to drive the circuit which helps in grasping and releasing of objects just as in actual arm, he explained.

''The aim of the project, to achieve maximum possible rehabilitation of arm amputees (below elbow at present) at reasonable and affordable cost, was achieved after about two years of hard work by a team of experts, he said.

The major breakthrough came when, after a thorough study of human anatomy, we were able to develop the device which could collect the microvolt signals through electodes put at a particular place, Arindam Chatterjee and Shashi Sharma, two members of the team, said, elaborating on how the robot arm worked.

''In the human arm, the contraction and relaxation of muscles produces Electromyogram (EMG) signals and the electrodes present in the myoelectic arm picks up these minute EMG signals accompnied by sound. The sound is filtered from these microvolt signals, is amplified by a factor of 1000, converted to DC signals and then digitised. Then these digital signals, through micro control progamme operates different relays, which operates the motor responsible for opening and closing of the fingers and thumb of the electromechanical arm, they said.

Just like the natural arms, the myoelectric arm works under controlled grip force. For example, for different functions, the prosthetic arm uses force according to the need, like for lifting a light objects it exert light force and for lifting a heavy object, it exert large force. It can be used by those amputees whose muscles are in good condition to generate such response.

''We are working on reducing the size and weight of the gadgets before launching it commercially,'' Dr Kapur said.

With little training, the patient can learn how to put pressure on muscles for sensors to pick it up and go about their daily work like before, using the electromechanical arm.

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