DEVICE FOR CAUTERY OF BLEEDING USING A SALT WITH LOW CRYOHYDRATE DISSOLUTION TEMPERATURE

Objectives The aim of the study is to consider the design of a device for the cautery of bleeding by the method of local freezing of the blood flow zone performed using a salt with a low cryohydrate dissolution temperature, as well as to model heat exchange processes when using this technique. Method A design for a device for cauterising bleeding using salts having a low dissolution temperature was developed. This ensures a high cooling intensity, shortening the time of formation of a thrombus stopping the blood flow. A model of the device was constructedaccording to the principlesgoverning the solidification of a viscous liquid and heat transfer associated with the dissolution of salts in water. The model was calculated using the finite difference method. A determination of haemostasis duration wasprovided by a numerical experiment. Results Plots of the temperature dependence of the salt solution in water over time are obtained, reflecting the duration of the device's output to operating mode, as well as plots of duration of a 3 mm thick formation of solid phase blood against the temperature of the solution for different values of blood flow pressure in the wound area. Conclusion On the basis of the numerical experiment, it was established that ammonium nitrate can be used as a working substance (salt) in the device. When it is dissolved in water, the minimum temperature of the solution is 256 K. The selection of the salt type and its quantity should be guided by medical norms and regulations in order to avoid the process of frostbite of the tissues adjacent to the bleeding zone. It was shown that the duration of blood solidification and the formation of a thrombus of the required thickness depend significantly on the pressure of the blood flow in the wound area, which must be taken into account when designing the device.