Социална мрежа за здравето - с грижа за вашето здраве

External prosthesis used to compensate for the loss of an upper limb have been known since ancient times. In the 21st Century, however, basic and primitive replacements have long since surrendered their place to a new generation of prostheses that are refined every year. In order to understand how the "prosthesis of the future" work, it is important to be aware of how the classic passive prosthesis work.

The type of prosthesis - passive, conventional or active - is determined primarily by the patient's specific needs and in particular the length of the amputation.

Passive and cosmetic prostheses

Passive propulsion prostheses are a cosmetic restoration of the appearance of the arm. This is just one of the options that are available to patients with an amputated upper limb. Such a prosthesis is acceptable in people who do not need precise grip management. In this case, the effect is mostly in the cosmetic field.

Body-supported prostheses

Conventional body-driven prostheses are typically attached with straps attached around the shoulder or upper body of the patient. These devices are controlled by moving the upper body. For this purpose a cable is attached, connected with the straps at one end and with the prosthesis (mechanical arm, hook, elbow) at the other end. In certain cases this type of prosthesis provides an acceptable range of basic functions and controls and is more functional than the cosmetic prosthesis.

Myoelectric prosthesis

The myoelectric prosthesis give even more control options. The prosthesis is controlled by reducing the muscles in hammering, generating electromyographic (EMG) signals. They in turn activate an electric motor in the elbow, wrist or palm. The myoelectric prosthesis allow for greater range of motion, more natural appearance and increased working capacity.

Hybrid Prosthesis

Hybrid prostheses combine elements of the conventional and electrically-powered prosthesis. These devices provide the ability to control the elbow and palm at the same time, which significantly increases the rehabilitation potential.

Specialized prosthesis

There are also activity-specific prosthesis designed for patients with special requirements. This type of prosthesis often uses tips designed according to the specialized activity the patient needs.

Such can be specialized prosthesis for various types of sports, leisure or work activities.

Modern prostheses not only look like real, but are designed to deliver the utmost realistic control and even deliver tactile sensations.

Bionics is a branch of science that studies the use of technical means and systems on the principle of organization, functions, structure and nature's nature. Bionics is an integral part of the paradigm of science such as biology, chemistry, cybernetics, physics, electronics and, besides medicine, is widely used in communications, navigation, seafaring, etc.

Among the most important areas of bionic studies are bionic prostheses and implants. The main feature of these prostheses is their ability to perform the function of lost limbs and missing organs.

The main difficulty in designing and developing a hand prosthesis comes from the extremely complex task of reproducing the delicate agility of complex finger movement, but also the possibility of feeling and touching.

The hand and fingers have some of the most complex and highly sensitive nerve endings. Therefore, it is no wonder that the creation of a 100% successful bionic hand project is still a challenge to specialized multidisciplinary teams of scientists.

Some of the more interesting attempts in this regard succeeded in getting closer to the ideal of an active, fully functional, autonomously controlled artificial hand.

Some interesting developments

In 2007, Touch Bionics launched i-Limb - a bionic arm-prosthesis project based on myoelectric devices that rely on bioelectric signals as a result of muscle contraction in the area of the limb. The project has prompted serious interest in the scientific field and was one of the most interesting commercial bionic projects over the last decade.

The i-Limb concept is based on information transmitted by nerves when different muscles contract.

A patient with such prostheses can perform various fine movements as well as hold objects with overall good control. The prototype of the prosthesis showed good results in fingers movement as well – while usually conventional prostheses do not offer much flexibility and efficiency. The work of the prosthesis is based on management software using information obtained from standard limb movements.

One of the most revolutionary achievements in the bionic hand is the regulation of the force of pressure, which is simply an irreplaceable quality in certain situations.

Over time, i-Limb undergoes a number of changes and upgrades that bring the prosthesis closer to the natural limb. For example, the bionic hand can itself return to its original state for a period of inactivity.

The Bebionic3 project is similar in principle to the i-Limb model and is also a myoelectric bionic hand. It is capable of fine motor functions that include precision activities such as working with a computer mouse, trigger pressing, using fine electronics devices and machinery.

Recently, Square Enix announced the development of a budget bionic arm as a joint project with Eidos-Montréal, Intel, Razer and Open Bionics. The interesting thing about this project is that the hand is inspired by Adam Jensen, the hero from Mankind Divided.

The project is royalty free, which means that everyone can make a 3D print and use the design.

The hand is fully functional, with folding fingers and swivel wrist, and the design is inspired by robotics and computer games.

Although the bionic prostheses are still far from the ideal of the natural hand, science and technology work in impressive synergy and deserve a lot of attention from the medical point of view as well as from the perspective of cybernetics, electronics, nanotechnology and a number of other areas of science.

Bionic developments for lower limb prostheses, also known as the "robotic foot", are a mechanical prosthesis that are able to compensate for the functions performed by the human foot.

The robotic or bionic foot is usually programmed to perform functions similar to the natural limbs in order to improve the movement and motor functions of patients who have experienced amputation or lower limb damage.

One of the most widely discussed achievements in this respect belongs to the Icelandic company Össur, which has developed an innovative bionic leg that can literally be controlled with thought.

The leg works by relying on information from small implanted myoelectric sensors. They are related to the residual true muscle fibers of the patient. Through them, the brain sends a signal to the corresponding group of muscles, and the signals are captured by implanted sensors. These signals are transmitted to the prosthesis, which in turn performs the desired movement.

The bionic device is designed to be intuitively "adaptable" to the individual movements of the patient. Thus its use becomes a "second nature" and over time the patient does not have to think volitionally about the desired movement.

Thus, the creation of an artificial bionic leg that is fully integrated with the patient's body appears to be a fully foreseeable achievement. Among the first patients to take advantage of this invention is the Dutchman Gudmundour Olufson, who has a knee-jerked leg. Using complex algorithms, the patient can move his own leg using signals from the brain, and the prosthesis obeys his commands.

Artificial heart is one of the most interesting examples of applying the principle of bionics to the needs of medicine. In short, an artificial heart is a device that replaces the damaged heart in patients with severe illnesses.

Artificial hearts are usually used to overcome time to heart transplantation, but in certain cases such devices are used to replace a definitively damaged heart when transplantation is impossible for one reason or another.

Historically, many different attempts and concepts have been used to replace or overlap the cardiac function in patients with severe heart problems, the most significant ones dating back to the late 1940s. However, the first attempt to replace the cardiac organ with an artificial one is the implantation of Jarvik-7 in 1982. The artificial heart is designed by the team of Willem Johan Kolff and Robert Jarvik.

An artificial heart differs significantly from the devices that support the ventricular activity of the heart as well as from the heart-lung machine. The idea of the artificial heart also differs from the functions of the cited devices in that its purpose is to replace the damaged heart for a constant or prolonged period, instead of just for the time of an operation.

Some of the more interesting and significant prototypes of total cardiac prosthesis (artificial heart) are:

• Jarvik-7 (1982)
• POLVAD (1991)
• Phoenix-7 (1996)
• AbioCor (2001)
• SynCardia (2003)
• CardioWest TAH (2003)
• MagScrew (2005)
• Abiomed AbioCor (2008)
• Carmat (2008)
• Frazier-Cohn (2011)

The successes in the development of artificial hearts are a real breakthrough in medicine and technology, but despite undeniable progress, this innovation is still in the process of perfecting and constant research.

Physicians and scientists are facing at least two serious challenges related to the use of artificial heart in patients requiring vitamin organ transplantation. First of all, the main problem is the rejection of the body graft - a problem that is also present in the donor heart transplant.

Among other problems associated with artificial heart transplantation is the so-called Cardioprotective psychopathological syndrome associated with fixation of attention to implant performance.

A cochlear implant (CI) is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing in both ears; as of 2014 they had been used experimentally in some people who had acquired deafness in one ear after learning how to speak. Cochlear implants bypass the normal hearing process; they have a microphone and some electronics that reside outside the skin, generally behind the ear, which transmits a signal to an array of electrodes placed in the cochlea, which stimulate the cochlear nerve.

The procedure in which the device is implanted is usually done under general anesthesia. Risks of the procedures include mastoiditis, otitis media (acute or with effusion), shifting of the implanted device requiring a second procedure, damage to the facial nerve, damage to the chorda tympani, and wound infections. People may experience problems with dizziness and balance for up to a few months after the procedure; these problems generally resolve, but for people over 70, they tend not to.

There is low to moderate quality evidence that when CIs are implanted in both ears at the same time, they improve hearing in noisy places for people with severe loss of hearing. There is some evidence that implanting CIs to improve hearing, may also improve tinnitus but there is some risk that it may cause people who never had tinnitus to get it.

There is controversy around the devices; much of the strongest objection to cochlear implants has come from the Deaf community. For some in the deaf community, cochlear implants are an affront to their culture, which as they view it, is a minority threatened by the hearing majority.

A cochlear implant is a medical device consisting of a microphone, a sound processor and a transmitter that can be placed externally (on the hair or skin of the patient), the receiver being implanted subcutaneously, and the electrodes passing through the earlobe using surgical methods.

A cochlear implant is an electronic device that helps the lost hearing to hear. There are external and internal parts. The implant does not return normal hearing, but emulates it by stimulating the auditory nerve directly with electrical impulses.

Operating principle

An external sound processor receives the sound waves from the environment and transmits them to the inside. The receiver in the cranial bone above the ear converts the sound into electricity and transmits it to the cochlea. The electrodes in it are in direct contact with the sound receptors. In this way, the electrical impulse surrounds the damaged parts in the middle or inner ear, reaches the auditory nerve, travels it and is processed by the brain.

The function of a cochlear implant is to stimulate the electrical impulses of the fibers of the auditory nerves in the earlobe. Such devices are designed for people with severe hearing loss, often with neurosensory etiology.

There are several systems available, but generally they have the following components:

External

• one or more microphones that pick up sound from the environment
• a speech processor which selectively filters sound to prioritize audible speech
• a transmitter that sends power and the processed sound signals across the skin to the internal device by electromagnetic induction

Internal

• a receiver/stimulator, which receives signals from the speech processor and converts them into electric impulses
• an electrode array embedded in the cochlea

History

The first primitive hearing aids and the development of oscillatory nerve stimulation techniques have been developed since the 1950s. Then the first attempts were made to create a cochlear implant for use in clinical conditions.

The first attempts to create a new generation of "bionic ear" stem from experiments conducted in 1978 at the University of Melbourne.

On the basis of this scientific development today is widely accepted a total cochlear implant, which has been put into use worldwide since the end of the year 2000 with positive results in partial hearing recovery for patients of all ages.

The bionic ear prototype, hailed as the first major advancement in the deafness treatment after the introduction of the sign language, was donated to the Australian National Museum.

Bionic ear of Australian Professor Graeme Clarke is the first modern cochlear implant that helps understanding and perceiving speech in patients with severe hearing disturbances and completely deaf.

Professor Clarke was appointed Head of the Department of Otorhinolaryngology at the University of Melbourne in 1970. He headed the team that developed a prototype of a bionic ear that was first implanted in 1978 by a patient named Rod Saunders.

Today, the most modern bionic cochlear implants are based on the principle developed by sin but with better sound-receiving qualities.

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