Loss of an arm or leg is devastating and many are not lucky enough to get prosthetic devices-even those who do take years to learn to use them. One of the cutting edge research developments in progress is to create a technology that makes artificial limbs lifelike-you would have the ability to control your prosthetic limb just like you did your normal limb!
A new generation of neurotechnologies will equip engineers with tools to devise devices that can be connected to the peripheral and central nervous systems and give amputees a chance to regain natural use of their artificial limbs. One avenue of research is the use of tiny injectable neurostimulators (shaped like a grain of rice) to activate weak and paralyzed muscles and spark them back to life; looking ahead, this has potential to revive paralyzed limbs.
Today, prosthetics like myoelectric arms operate through mechanical movement and give users limited range of motion of about three degrees of freedom as opposed to the 22 degrees of freedom of a normal arm. Research aims to increase the range of movement to 22 joints and move the shoulder in order to match the performance of the human arm while maintaining ability to control the arm. Of course the biggest task is going to be to build a sophisticated control system that will replace parts of the nervous system and allow the user to operate the artificial limb just by thinking about it.
Before prototyping, arm performance is modelled in a virtual reality environment to allow engineers to refine the design and give patients a chance to learn to operate them; computerized models of the musculo-skeletal system mimic movement in the body and aid data collection of how arms swing or how much force is needed to reach for an object on a table, for example. In the simulation environment, a patient produces command signals by voluntarily contracting intact muscles/joints to control movement of the prosthetic limb; he/she watches the arm motion in 3D and changes the command signals until satisfied with the results.
Biomedical engineers are developing neural implants for the brain and spinal chord. With research on silicon chip brain implants underway-this has potential in the overall effort to replace parts of the nervous system that must be bypassed to restore full function.
An intriguing aspect of this research is the increased interest in adding sensory perception at the fingertips of the prosthetic limbs so that patients can conduct everyday tasks-even in the dark! Isn’t that phenomenal?
We live in times where prosthetic arms and legs while impressive, provide a limited range of movement and primitive ability to grasp objects and in all honesty, it will be a while before we are willing to swap a real arm for a prosthetic one, but the breakthrough work that heavily involves integration of a number of circuit functions cannot go without recognition-I just had to share these developments with you!
Author is interested in emerging technologies and their impact on business and society; she is a postgraduate student in Electrical Engineering at the University of Pennsylvania (USA).