Y.A. Ershov - Dr.Sc. (Chem.), Professor, Department of Medical Engineering Information Technology, Bau-man Moscow State Technical University E-mail: ershov_54@mail.ru V.B. Akopyan - Dr.Sc. (Biol.), Professor, Department of Medical Engineering Information Technology, Bau-man Moscow State Technical University E-mail: akopyan1941@mail.ru S.V. Alkov - Ph.D. (Eng.), Department of Medical Engineering Information Technology, Bauman Moscow State Technical University E-mail: alkov@bmstu.ru A.A. Petrosyants - Student, Department of Medical Engineering Information Technology, Bauman Moscow State Technical University E-mail: petrosyants1580@gmail.com

Ultrasonic (US) desintegration of the cloudy ocular lens is effective and atraumatic method of cataract removal, prior to implantation of an artificial intraocular lens. US methods in medicine, in some cases, and particularly at opthalmo-surgical method of desintegration and removal of the opaque lens for replacement were used successfully many years ago. However, the mechanisms of US action on biological tissues have not been studied up to the last date. Lens capsule contains protein gel consisting of 30% protein and 65% water. Some researchers suggest that US tool acts on the lens like a miniature jackhammer. Other researchers believe that the main role in US destruction of the lens are playing shock waves and intense micro-streams caused by US cavitation. Researches and surgical practice revealed that under the action of ul-trasound the gel of lens viscous proteins liquefies and can be easily removed by aspiration. Under the US action cell membranes of the lens are destroyed, intermolecular interactions and chemical bonds in the pro-tein molecules are broken. As a result, the viscosity of the lens content is reduced. Under the influence of cavitation the medium is further liquefies, making it possible to its aspiration during surgery. Viscosimetry methods show that the dependence of the rate of albumin model gel liquefaction under the ultrasound expo-sure mode is determined not only by characteristics of ultrasound, but also of the gel characteristics. In this study of the US action mechanism was used model viscous medium having the property of liquefaction/ It were na-tive and heat-denatured ovalbumins. In the first approximation two type aqueous gels of albumin (90% egg albumen - 10% water or 35% protein - 65% water) was used as models of the lens afflicted with cataracts. As US source was used apparatus for US surgery with an operating frequency of 26.5 kHz. The amplitude of the working tool oscillation was ~ 10 microns. On the model with 90% protein in water it was shown that under the action of US instrument at a frequency of 26.5 kHz and an amplitude of oscillations of the working part about 10 microns, the protein structure is destroyed within 50 seconds and the gel turns into a low viscosity fluid. In this case US cavitations are possible. Associated cavitation shock waves and intense micro streams accelerate the de-struction of the gel structure. It is obvious that a similar phenomenon occurs in case of ultrasonic destruction of the con-tents of the lens. Тhe results of this study shows that under US exposure protein gel is converted into an aqueous solution of low molecular weight peptides. Therefore the widely used term «phacoemulsification» is wrong in principle, and instead of the term "phacoemulsification" should use the term «phacodispersion».

 

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