Timanin E., Eremin E., Didenkulov I.

A number of ways of tissues structure visualization are developing now based on their elasticity mapping. At the same time traditional measurements of mechanical characteristics of biological soft tissue stay to be vital to characterize its condition affected by various physical, physiological or medical factors. One of the most suitable ways of measuring the mechanical parameters of tissues for this purpose is a way based on registration of dynamic mechanical characteristics of tissues (dynamic stiffness and mechanical impedance) when touching them by vibrating disk. At this principle computer-based devices have been developed providing measurements of elasticity and viscosity parameters of soft biological tissues by the hand-held probe. The probe includes vibration exciter and sensors of force and acceleration, supplying signals to determine dynamic stiffness and mechanical impedance. Two types of devices are constructed. Noise-type vibrations are used by the first one as well as signals acquisition through the LineIN input of PC sound card and their spectral processing. Harmonic vibrations are used by the second one as well as signals acquisition through the USB input of PC and their processing over the period. Frequency dependencies (spectra) of stiffness and impedance are recorded by the devices of the first type and temporal dynamics of these parameters is recorded by the devices of the second type with resolution less then 0.1 of second. Both Spectra Recorder of Mechanical Impedance and Dynamic Stiffness (SpR MIDS) and Temporal Dynamics Recorder of Mechanical Impedance and Dynamic Stiffness (TDR MIDS) can work with desktops and laptops in any MS Windows. Means of modules estimate of shear elasticity and shear viscosity of tissues are included in the managing programs of devices based on models of vibrating disk interaction with testing media (semi-space, single layer on a rigid base or double layer on a rigid base).