For a long time now, projects with the object of creating an artificial limb that could be controlled by the patient’s thoughts have been known.To the well-known technologically advanced prosthesis projects belong: an international project Smart Hand, prosthesis of a British Touch Bionics, an Otto Bock company’s and dr. Todd A. Kuikenen’s from Chicago due to which the patient is able to feel the touch. Worth mentioning is also a Japanese model in which innovative control system was employed. It figures, that the patients after injuries can hopefully look forward to recovery.
Until now, the two types of mechanical prostheses have been used. One of them works on the basis of system of strings, which when properly strained by the second hand move the artificial limb. More advanced projects are based on electrodes affixed to skin. When appropriately trained patient flexes, for example, chest muscles, the impulse received by the electrodes is transferred to a certain engines, which cause the movement in artificial joints.
Another solution was employed in Touch Bionics model. The prosthesis by the name of I-limb has one of the greatest operating range. Due to electrodes affixed to the skin of forearm, the movement of all fingers is possible. The patient can boldly eat, brush his or her hair and even squash cans. The 90 kg weight is possible to be lifted. It is also possible to regulate the strength of pressure which is conveyed in the form of vibrations felt by the patient. The advantage of such method is the possibility of using it without the necessity of surgery.
Video presenting Touch Bionics accomplishments is available on the following link:
Another technologically advanced project is Smart Hand. It’s the effect of an international cooperation financed by the EU. Research is conducted inter alia in Sweden where works dr. Fredrik Sebelius – the coordinator of the project. In Smart Hand electrodes are affixed to the stump and additionally implanted beneath the skin. They may enwrap around nerves, transferring the impulse to engines which move the hand. Remarkable is also a fact that the limb receives sensory impulses. To enable that the scientists developed a sensory map of the stump. According to them, on the stump’s skin there are places, which when properly activated, cause phantom sensation, for example, of amputated fingers. After the stump’s sensory map denotation, sensors’ reception of stimulus from amputated fingers and their analysis, the skin is pressed in certain areas that gives the impression of touch in fingers.
An exemplary operating range of prosthesis can be seen on the following link:
Also in the USA and Germany, the work on bionic limb continues. In the USA dr. Todd A. Kuikenen, who performs function of the director of the Centre of Neuro- Engineering in Rehabilitation Institute of Chicago, leads a crew working on the artificial limb which feel the touch, cold and warmth. However, the German engineers present their achievements inter alia in Otto Bock company. The gist of their project is to transplant nerves from injured limb which is going to be amputated. The nerves are transplanted into the chest. After some time they meld with muscles and ceptors of the skin creating its new sensory map. Stimulating some parts of skin properly, it is possible to cause sensory effect. This mechanism allows to decrease phantom pains. The effect is evident on the following links:
The achievements of Japanese engineers may be a breakthrough. Yet, in 2006 the scientists of Neurobiological Laboratory in Kyoto under the guidance of dr. Yukiyasu Kamitani have presented an artificial hand controlled by thoughts. MRI monitoring brain areas activity is used for that purpose. collected data are analysed in computer and subsequently send to the prosthesis which can twist bottles or even play rock-paper-scissors in actual time.
All above mentioned projects indicate that people who have had their limbs amputated or lost in other way can look forward with the prospect of better tomorrow. Deadening phantom pains and the possibility of doing various activities will benefit the patients’ lives. Considering the international competition, the price of mechanical prostheses will certainly recede, thereby their availability will increase making human life more comfortable.