The effects of elastic waves on biological objects elastic waves in nature, science, engineering, technology, medicine

C_м =V/ p_ас S₂² , (2.5)
where V is the volume of the chamber, is the specific gravity of blood, p_ас is the pressure inside the chamber.
In the heart model diagram there are 8 chambers arranged along the length of the whole cardiac system L=6 mm=6 x 10^-3 m. The data used for the calculation are: length of one of the chambers of the cardiac system l_k =7.5 x 10^-4 m, cross-sectional area of the chambers S₁ = d₁² /4 1x10^-3 m² , where d₁ is the diameter of the chamber.
On the basis of the body dimensions of the Colorado potato beetle given in the encyclopedic dictionary of F.A. Brockhaus [174] we accept that the body height of the Colorado potato beetle is ~3.5 mm, and the diameter of the ostium is approximately 1/7 of the body diameter of the insect, then we have data for calculation: d₁ =5 x 10^-4 m. Blood density is =1 x 10³ kg/m³ . According to previous works of G.I.Sokol [167] the mass of one chamber t=7,5 x 10^-8 kg. Then total mass of available chambers t_ =6 x 10^-7 kg. Volume V of one chamber with mass t is equal to V=t/ =7,5x10^-11 m³ .
With a conventional count, the acoustic pressure of the blood inside the chamber was p_ас =200 N/m² , and the specific gravity =9810 N/m³ . The flexibility of one of the chambers cavity K=V/ p_ас S² =3.8 x 10^-3 m/N. For a multi-chambered insect heart, the stiffness of the available chambers S_ can be written as
, (2.6)
where C₁ , C₂ , ..., C₈ are the stiffness values that correspond to the corresponding chamber in the insect's cardiac system.
The stiffness of one chamber C=1/K=263 N/m. According to (5) the total stiffness of the available chambers 1/C_ =1/263 x 8=3.04 x 10^-2 N/m was determined. Hence C_ = 32.8 N/m. The resonance frequency of the heart of the Colorado potato beetle was f=1179 Hz.
The result corresponds to the range of resonance frequencies that were determined to be detrimental to the Colorado potato beetle during the tests carried out.
The third method for determining the resonance frequency of the Colorado potato beetle heart is based on data from the work of J.C. Fyn [175]. Using them, the stiffness and elasticity of the capillary muscle of the insect heart can be calculated. Fyn developed load-elongation curves for rabbit cardiac capillary muscle specimen under periodic loading and unloading at constant rate. The study was conducted
at 37°C and the elongation of the muscle was L₀ =0.936 cm. Using the obtained data, G.I. Sokol [164] calculated stiffness and elasticity of the capillary muscle of the Colorado potato beetle. He considered that capillary muscles of rabbit and Colorado potato beetle heart have the same mechanical characteristics. The effective force F=0.01 kg, the elongation of the insect's muscle x=1/0.12 m. Then the stiffness of the heart muscle was C=F/x=0.0012 kg/m, and the flexibility K=1/C=833.3 N/m.
Let us determine the resonance frequency of the heart of the Colorado potato beetle using the values previously obtained by G.I. Sokol mass [169]. Resonance frequency of the Colorado potato beetle heart was f=638 Hz. This result is also close in its order to those frequencies which proved to be destructive for the Colorado potato beetle during exposure to vibrations. Thus, the result obtained by G.I. Sokol [164] confirms that, as a result of studies, the Colorado potato beetle died due to heart damage.