When a person loses a limb, his main dream is to feel his arm or leg again. And not just to feel, but to perform with a limb all the movements available before an injury or illness: take a cup, lace up shoes, walk with support on both legs. Bionic prosthesis, or a complex device that catches nerve impulses, allows you to regain lost opportunities.
How did smart prostheses come about?
The prototype of “living” prostheses was invented and described by science fiction writers. It was in their works that mechanical assistants working better than living organs came to replace the arms, legs, eyes and hearts lost in the battles. The most famous example is the Cameron Terminator, which has taken from a person only the appearance.
Few people know that the prototype of modern prostheses dates back to the 19th century, when a metal ball was inserted into a wooden leg to make the lower part movable. But in the 20th century, these primitive devices were replaced by a bionic prosthesis, created at the junction of several sciences: medicine, engineering, bionics and electronics.
Scientists from different countries dispute the primacy in this matter, but the facts are such that the first functioning bionic prosthetic arm was presented at an orthopedic exhibition in the German city of Leipzig in 2010. In the several years that have passed since this event, a huge number of prostheses of the hands, arms, feet, legs, and even dog paws have been developed in the world.
What is bionics?
This is a whole science that studies wildlife and the possibility of transferring the principles of living creatures to industrial analogues. Engineers spy on ideas from nature and embody them in their devices and structures. In this sense, bionic prostheses are just a drop in the bucket. So, the well-known Velcro fasteners just copy the way the seeds of burdock move. Suckers are borrowed from leeches. When designing submarines, they took the earthworm as a sample - it has all the "compartments" autonomous. Incredibly hardy metal openwork of the Ostankino and Eiffel towers is a multiply enlarged copy of the human tubular bone. The metal weaves that delight everyone so much are a copy of the bone structure that combines strength and flexibility.
Even a multi-storey building, in which such different families live at the same time, has been written off from honeycombs. The idea of ​​different people living in “cells” under one roof with common communications copies the way of life of a bee family.
There are bionic incarnations in many objects surrounding us: car tires, airplanes, surveillance cameras, watercraft and the most common articulated joints.
How does the simplest bionic prosthesis work?
After an injury or during an illness, an extremity is amputated. The remaining stump consists of many tissues: skin, muscles, bones, blood vessels and nerves. The surgeon during the operation removes the preserved motor nerve to the remaining major muscle. After the healing of the surgical wound, the nerve can transmit a motor signal. This signal is received by the sensor mounted on the prosthesis. A complex computer program is involved in the process of perceiving a nerve impulse.
Therefore, a bionic prosthesis can perform only those actions that are prescribed in this program: take a spoon, fork or ball, press a key, and the like. Compared to the absence of a limb, the possibility of even a limited number of movements is tremendous progress. However, even the best and most perfect bionic prostheses can not yet perform all those small and precise movements that a living limb is capable of.
How does a nerve impulse pass from the brain to the prosthesis?
To understand how bionic prostheses work, you need to remember the normal physiology of a person.
The movements that we make many times during the day are called automatic. Lifting, going to the toilet, washing, brushing teeth, dressing - all this does not cause us any thoughts. The body does everything that is needed as if by itself. But in fact, the beginning of any movement is thought. That is, at first we think: we need to brush our teeth, make coffee, get dressed. The brain sends signals to those muscles that are involved in this movement. A muscle can contract or relax only at the signal of the brain. But the process goes so fast and smoothly that we do not have time to realize what is happening. In the case of the prosthesis, everything is more complicated: at first, the motion signal is read by the electrode located next to the nerve that is pulled out to the muscle, and then sent to the processor inside the prosthesis. This process is also quite fast, but the speed of the action is still inferior to the living limb.
Artificial human "parts"
Since the first bionic prosthesis was introduced, science has gone far ahead. If the first models were bulky, required switches and could perform only the simplest movements, then modern designs can hardly be called prostheses. These are elegant engineering products, as if descended from the screen of futuristic films.
The prosthesis is absolutely similar to a healthy hand, they can write, hold cutlery, the steering wheel of a car or a chicken egg. For perfect movements, sometimes the person’s own tissues are used from other parts of the body - from the legs, for example.
Ideas from the future
Engineers and scientists in their fantasies are unstoppable. So, scientists were even able to "go around" the damaged retina, transmitting the image of the surrounding directly to the optic nerve. A person who is blinded as a result of an injury, while preserving the optic nerve, can count on seeing his relatives again or a beautiful sunrise.
Devices that improve brain function have already appeared. So, with trembling paralysis or Parkinson's disease can be dealt with using an implanted electrode.
People who become motionless due to paralysis are implanted directly into the brain so that they can control their artificial arms and legs. For a person who is completely dependent on others, the possibility of self-service is an unspeakable joy.
Discusses the issue of implantable chips under the skin that can replace keys, a bank card and an identity card at the same time.
What about us?
The most famous enterprise producing bionic prostheses in Russia is the Moscow prosthetic rehabilitation center. Here, prostheses from modules are assembled, products from Germany, Iceland and Russia are used.
The prosthesis of each person has individual characteristics. This is the level of amputation, and weight, and height, and occupation, especially gait and small movements, age. Many self-learning modules are used. Not only does the person adapt to the prosthesis, but the prosthesis also adapts to the person. A self-learning module, equipped with built-in artificial intelligence, remembers the features of the gait and route of movement. The module "teaches" not only the step width and the load on the limb, but also remembers the number and height of steps, potholes, and pits along the way. Modules copy the actions of the brain preparing the step or other movement.
How much does a live prosthesis cost?
The cost of bionic prosthetics is still high and can reach millions of rubles in difficult cases. However, a return to a full life is difficult to evaluate in material terms. In fact, the installation of bionic prostheses is the only way for a disabled person to return to normal life: to build and implement plans, support a family, and achieve career heights.
The most important thing is to return to the community of healthy, self-reliant people. People with "live" prostheses continue to lead a familiar lifestyle, dance and even receive sports awards. That is, the prosthesis becomes a part of a person so that it is difficult to distinguish the actions of living muscles from their bionic counterparts.
Prosthetics: stages of development
Compared to a conventional bionic prosthesis, the brush is a real breakthrough. More recently, a person who lost a hand could count on only two possibilities: a skin flap was formed between the ulna and radius, so that a person could capture large objects, or a hook was attached to the cult. Both that, and another was inconvenient and unaesthetic. Today, even the formation of a stump for a future prosthesis begins in the operating room. From the first days of the postoperative period, a prosthetist works with the victim, helping to choose the best combination of parts. The stump is formed and trained, and parts of the future prosthesis are maximally adapted to the remaining possibilities. A delicate silicone cuff with integrated chips comes into contact with the skin. Scuffs from modern prostheses do not happen. The program for each product is developed individually, depending on what the person is doing. The task is the maximum restoration of the function.
Help for the disabled
A person who has lost a limb must undergo a medical and social examination. Along with the establishment of a disability group, a social rehabilitation program is being developed for everyone. Rehabilitation involves the use of primarily technical means that contribute to the return of a person to work. All bionic limb prostheses are included in the mandatory list of such technical equipment. A person has a choice: within the framework of a rehabilitation program, to receive a finished product or to purchase it yourself with the subsequent receipt of monetary compensation. The amount of compensation is calculated based on the average cost of similar prosthetic products.
What are the developers working on?
Modern bionic prostheses of the hands perfectly perform subtle movements, but a person does not receive from them those sensations to which he is accustomed. So, a prosthesis can stroke a person’s hair, but you can’t feel the warmth of the scalp and the softness of the hair. Scientists are now engaged in the elimination of precisely this shortcoming. Specialists have already learned how to merge bones with titanium, and to connect motion and sense sensors directly to the living nerve. So, the bionic arm completely replaces the living one, and the person receives tactile sensations, which he has been deprived of for many years. The direct connection of nerves and muscles with a technical device greatly increases the speed of movement, bringing it closer to the natural.
What parts does a bionic leg consist of?
A modern bionic prosthetic leg includes several essential elements, such as:
- silicone cuff with integrated sensors;
- support - a titanium rod shaped like a drumstick;
- articulated module with micromotors and a processor;
- artificial intelligence unit that processes all incoming signals.
The latest prosthetic models of leading German companies have a special coating, very similar to the skin. Synthetic skin has a dual purpose: protects the parts of the prosthesis from moisture and performs a cosmetic function. You can not remove the coated prosthesis, take a shower with it and walk through the puddles.
A bit of fantasy
Today, several people live on the same planet with us, having 2 or even 3 bionic prostheses at the same time. Synthetic leather invented to change stiffness. Exoskeletons were invented to help paralyzed people walk. Products controlled by the power of thought are being developed. Experiments are conducted on growing nerves in microchannels. Theoretically, the day is near when it will be possible to grow a nerve of the desired length. Scientists are trying to blur the line between wildlife and technology. The number of movements performed by bionic prostheses is constantly increasing, and their complexity is also increasing.
All this gives great hope that a person will become stronger than the disease.
Prosthetics of the extremities becomes a routine procedure that returns a person to the usual course. Perhaps the day will come when any part of the human body can be replaced by an artificial one. At least I really want to believe it.