Pressure influence on morphological and functional changes in forearm tissues research

The work is devoted to the study of the effect of pinning on morphofunctional changes of forearm tissues. The studies were carried out with healthy volunteers using a special laboratory complex, the main components of which are a precision motion bench in a design with an ultrasound sensor and force transducers. The paper shows the dependences of changes in thickness of inner layers of the forearm, namely skin-fat and muscle layers, on movement and force of the ultrasound transducer clamping. Electrical impedance signal is one of the promising methods of controlling bionic devices. To exclude the influence of changes in skin-fat layer thickness on electrical impedance signal, it is necessary to find the value of electrode systems pressing force, at which the thickness of the skin-fat layer will decrease and remain constant. In this case, it is possible to obtain a repeatable pattern of electrical impedance signal, associated directly with muscle contraction. As a result of the studies, it was found that skin-fat layer elasticity is less than that of the muscle layer, because when the pressing force increases, the skin-fat layer thins first, after which the muscle layer begins to thin. The pressure exerted by the electrode system on the forearm and the associated changes in the thickness of the forearm layers should be considered when developing proprioceptive control systems for bionic devices based on electrical impedance signal registration.