Custom manufacturing of upper limb prostheses: comfort, functionality, natural movement
Upper limb prostheses are designed to meet the functional needs of people with limb loss at various levels. Depending on the level of amputation, hand prostheses are divided into shoulder prostheses, forearm prostheses, and hand prostheses.
According to their functional characteristics and method of control, hand prostheses are divided into cosmetic, functional (traction and working) and myoelectric.
Our patients can receive different types of upper limb prostheses depending on their needs and level of functionality:
Persons with two or more lesions of the upper and/or lower extremities are provided with one prosthesis for each affected limb per year, which allows maintaining full functionality and comfort in everyday life.
Cosmetic prostheses can be made for almost all levels of amputation — from a finger to the shoulder joint. However, they have a limited level of functionality, and visually imitate the lost part of the limb. They can only help you hold something that is not heavy and not large, if we are talking about a cosmetic prosthesis above the hand. They consist of a stump-receiving sleeve, an artificial hand and a cosmetic shell. Cosmetic prostheses improve the appearance and maximally replicate the preserved limb.
Functional prostheses are designed to perform certain tasks by the prosthesis owner. Control is provided by traction. Their main feature is ease of mastering. They are actuated by movement in the joints of the shoulder girdle. The traction prosthesis is controlled by traction and is fully controlled by the user's efforts. When performing a grip, the user determines its strength and speed and can feel the resistance from contact with the object.
Prostheses with an external energy source (myoelectric)are equipped with an external power source. With the help of muscle impulses intercepted by sensors located on the surface of the skin, they allow you to control the prosthesis, in particular the wrist and fingers. The greatest number of manipulations can be performed in the hand modules. Depending on the modification, it is possible to control from two to five fingers with the ability to individually adjust them to facilitate the most frequent movements (holding a toothbrush, cup, plate, typing on a computer).
Myoelectric prostheses are divided by amputation level:• forearm prostheses;• wrist prostheses;• hand prostheses.
Myoelectric prostheses are made for patients of almost any age, including children. These types of prostheses can be equipped with inductive batteries even in the case of amputation of the hand – using batteries that are an integral part of the prosthesis.
Quick mastery of such prostheses occurs if the patient has completely healed wounds, a well-formed stump and has experience using a mechanical traction prosthesis.
Let's consider a number of aspects related to bionic hand prostheses.
A bionic hand prosthesis contains built-in electrodes. For the prosthesis to work properly, it is necessary that the corresponding muscles are active and that the stump-receiving sleeve fits tightly to the residual limb (i.e., the stump must be stable, not significantly change in volume), because the electrodes receive signals from the muscles and convert them into one or another function of the bionic hand.
When a limb is amputated at the shoulder level, electrodes read signals from the person's biceps and triceps, transmitting them to the elbow; then through a switch to the hand, sometimes through a rotating wrist.
A number of studies that evaluated the quality of control of a bionic prosthesis by patients have shown that today the level of passive use or complete rejection of such a prosthesis is quite high. This is mainly because there is no reverse bio-feedback when using the prosthesis. The user relies mostly on vision to perform an action with the prosthesis, but does not receive neural feedback. When using traction-controlled prostheses, users report a better level of "feel" prosthesis, but in the case of amputation at the shoulder level, a patient with a prosthesis controlled by an external power source makes less effort to activate the functions of the terminal device (hand or hook).
In the case of providing upper limb prostheses, individuals are provided with two types of prostheses of different functionality, namely:
Military personnel are provided with two types of upper limb prostheses, respectively:
Persons who have multiple (two or more) upper and/or lower limb lesions are provided with prostheses at the rate of one product per affected limb per year.