Prosthesis
As we have said, prosthesis are becoming more and more common to see, they are made of very resistant and expensive materials, even if we continue to look for inexpensive, long-lasting and resistant materials.
But how do prostheses relate to our "healing" concept? well, in this case it is simple to answer because these mechanical parts, built in stainless steel, cobalt, chromium and titanium alloys, plastic and polyethylene, are mainly used for the healing of those people who were born with genetic problems and therefore with to the limbs or organs, or for those people who during their life due to accidents have found themselves having significant motor difficulties.
In the subject of prosthesis, however, there are also negative sides, in fact there are pros and cons, as in everything :
PROS
One of the pros is to regain the ability to use a lost part of the body really close to the lost one or maybe even better.
Another one is to gain more stability and endurance with the biocompatibility of the materials that makes the prosthesis more safe so that it doesn't cause signs of infection with what it is in contact with.
With 3D printing it will be possible to have prostheses economically within everyone reach and everyone will beable to design and print their own. You can make your own hand for about $50. Body scanning technologies also allow you to create natural-looking models.
Not to mention that 3D printers are becoming compatible with ever new materials, such as lightweight titanium.
CONS
Instead one of the cons is that a prosthesis isn't in fact a natural part of the body, but just a replication. So, even if we create one very close to the real one it will never feel like what we had, in fact, the sensitivity and perception will never be the same as before.
Another cons is that a prosthesis doesn't last long like a natural one, so you have to do a check every year, change a prosthesis with another and of course this isn't free at all, you have to pay a lot of money just for a check-up and you have to pay another amount for the new prosthesis and, if you don't, it can harm you in various ways, for example the prosthesis can stop functioning in any moment.
Types of prosthesis
Passive prostheses: they are the simplest, in fact, they are not able to carry out movements (output) actively, nor to receive inputs from the body (both the classic wooden leg of the pirate are passive prostheses but also the legs of parachute runners - Olympians)
Electromyographic prostheses: they are able to perform a series of positions/combinations (albeit in a limited number). They are the first bionic limbs as they can receive information from the body and respond with outputs, as the original limb would.
Neuromusculoskeletal prostheses: they exploit the residual nervous system of the amputated limb byconnecting it to the prosthesis.
Tacticle prosthesis
A group of researchers from the University of Glasgow, in the United Kingdom, has developed a version that would exploit the sun's rays to power those sensors that allow electronic skin to imitate human skin. Furthermore, they succeeded in superimposing a layer of photovoltaic cells on the back of a prosthetic hand on which sensors were added. These sensors were made of graphene, a flexible material stronger than steel, electrically conductive and transparent.
In addition to simulating the movements of the part of the body involved, the prostheses of the future will also be able to recreate the sensation of touching and feeling. Research is already working to create an intelligent synthetic skin, with built-in sensors, that simulates the tactile feedback of human skin, making it possible to feel pressure, temperature and even humidity.
The Italian bionic hand with the sense of touch
Among the most innovative creations in terms of prostheses equipped with a sense of touch is the one created for Almerina Mascarello who today is the first woman with a bionic hand that has the sensation oftouch. The surgery was performed at the Gemelli Polyclinic using technology from the University of Pisa. When the fingers of the bionic hand touch something, the signals they generate are sent to the computer which then processes the information and transmits it to his brain via electrodes connected to the nerves in his arm.
Natural Bionics
Another way to regain the sense of touch. This project aims to use the residual nervous system in a completely different way: obtaining a nerve image of the amputated limb in the brain. Ideally the speech is similar to phantom limb pain, patients perceive the painful limb even though it is no longer there and this is possible because a memory of pain active tion in those areas is still present in the brain. This project consists of two fundamental stages:
• The creation of the manunculus: a flap of skin removed from the patient's body which is connected to theamputated limb. The hope is that the re-connection of the nerve fibers of the residual limb with the nervefibers of the excised skin will form a nervous image of the missing limb in our brain, so as to have aninterface which, if suitably stimulated by the prosthesis, send signals to the brain. So as to obtain the return of the sensation of touch.
• Coding of output signals, the prosthesis must be taught to read and decode the different stimuli that come from the brain.