Multi-stage precooling cryoablation method and device

Abstract

The invention discloses a multi-stage precooling cryoablation method. In the method, a freezing medium is fully cooled in a plurality of precooling heat exchanger to achieve the ultimate low temperature, and is evaporated and expanded on the top end of a cryoprobe or a canula for the cryoablation of a targeting biological tissue, such as tumour, cardiovascular tissues or other pathological tissues. The method can greatly enhance the freezing efficiency and the freezing power, and enables the treatment become to be fast and effective. The invention also discloses a device implementing the multi-stage precooling cryoablation method.

Description

technical field [0001] The invention relates to a method for using multiple pre-cooling heat exchangers to make the refrigerant reach the final low temperature, in particular to a multi-stage pre-cooling freeze-thaw method; the invention also relates to equipment for implementing the above method. Background technique [0002] Cryoablation systems can be used to remove lesions or repair physical defects to restore and improve body functions. It is used in many departments of surgery, such as ear, nose and throat tumors, gynecological cervical tumors, breast tumors, urological prostate tumors, etc. It is also used to remove gastric tumors, liver tumors, and brain tumors. In addition, cryoablation can also be used for cosmetology, skin disease treatment, tonsillectomy, hemorrhoid removal, cataract removal, etc. Compared with some other surgical methods, cryoablation therapy has the following obvious advantages: (1) Low temperature can shrink or even coagulate blood vessels, w...

AI Technical Summary

Problems solved by technology

The smaller the diameter of the cryoprobe, the easier it is for the flowing nitrogen flow to be blocked in the cryoprobe, resulting in poorer refrigeration performance

Therefore, in order to ensure the cooling effect, it is difficult for the diameter of the general cryoprobe to be less than 3mm.

(2) The cooling speed of the cryoprobe is relatively slow, and the pre-cooling time is relatively long, which is not conducive to killing diseased tissue cells

In addition, because the temperature of liquid nitrogen is very low, and the temperature of the equipment is relatively high, in order to prevent the vaporization of liquid nitrogen, the equipment is often equipped with an extra insulation layer to prevent the equipment from absorbing heat from the outside, so the liquid nitrogen refrigeration equipment is generally large in size

[0005] Although the argon-helium knife cools and heats up quickly, the cooling power is not very large, and the rewarming effect caused by helium throttling is very limited, and the expected effect may not be achieved in actual surgery

On the other hand, the amount of argon and helium is large and the source is difficult. High-purity argon is expensive, and it is not a small burden for patients to perform an operation.

Moreover, the pressure of this set of equipment is relatively high, generally in the range of 25-40Mpa. Under such a large pressure, the pipeline is prone to leakage, and the requirements for various valves are greatly increased.

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