Patients who choose to cut off their limbs to be fitted with a robotic one is not a new story anymore. Elective amputation is, therefore, a stepping stone for the advancement in bionics and it is testifying that patients now prefer technological alternative over the conventional biological treatment. Hence, prosthetics are now a viable option and not merely the last resort.
It was a motorcycle accident in 2001 that deprived Milo of the functioning of his arm. He crashed into a lamppost, receiving severe injuries in leg and shoulder. While his leg recovered, the shoulder didn’t. Milo’s arm was paralyzed owing to the damage of brachial plexus (a network of nerve fibers in shoulder). Doctors transplanted nerves from Milo’s leg into his right arm to restore some limb activity. The transplant was partially successful as it restored movement in the arm but not the hand. After years of living with a crippled hand, Dr. Oskar Aszmann from the Medical University of Vienna suggested a prosthesis of a bionic hand.
The artificial hand was manufactured by Otto Bock, a prosthetics company in Germany. The arm is made up of six sensors that pick up the neuronal signals sent to the forearm from the brain to control arm and hand movement. The function of the bionic arm is to convert those electrical signals into mechanical movement.
The Otto Bock hand is quite adaptable. It has three degrees of free movement: rotation of wrist, flexion and extension of wrist, and movement of fingers. Fingers can be used for both gripping and pinching. Despite all the progress in prosthetic limbs, the movements are still not naturally smooth. This is because electrical signals originate in the cortex of the brain that is responsible for movement. As it passes through the arm, its translation to mechanical movements is a tricky, complex, intertwined, and multi-step process.
The concept of an ideal prosthetic is that it must have atleast an equal functionality as that of a real limb, if not more. Something like this would need a sensory feedback system. The prosthesis would generate vibrations to send feedback of different parameters like hand position, the velocity of movement, or grasping strength. Instead of focusing hard on the movements, the amputees will simply be able to feel it, making it almost as effective as a real limb. Touch Bionics has a really good product in shops that can be adapted to every patient’s disability.
Soon Milo will be able to do small tasks himself like gripping water glass, tying shoe-laces, and maybe go for a ride on his bicycle.
Here’s the video of his story.