RU2713947C2 - Apparatus for cryotherapy - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment and can be used for external cooling of human pathological tissues in cryosurgical operations. Apparatus for treating cold includes a compressor, heat exchange apparatus, a gas expansion device and an air cooling apparatus and consists of a hardware and a tool portion. Hardware includes series-connected compressor, which discharge pipeline is connected to inlet branch of air cooling device, tubular-fin heat exchanger equipped with fan, which is connected to separator, pipeline of coolant gases of which is connected to input of heat-exchange apparatus of preliminary cooling, and liquid pipeline is connected to throttling device, connected to inlet of low pressure of heat-exchange apparatus of preliminary cooling, high-pressure outlet of heat-exchanging device for preliminary cooling is connected to inlet of high pressure of the main heat-exchanging device, high-pressure outlet of which is connected to electronic expansion valve, which is connected through flexible hose to evaporator with throttling effect. Instrumental part comprises a cryo-tip on which an evaporator with throttling effect is wound so that the evaporator outlet is at the tip of the kick gun, wherein evaporator output with throttling effect is connected via flexible hose with low-pressure inlet of the main heat exchanger, outlet of which is connected to inlet of heat-exchanging device for preliminary cooling, outlet of which is in turn connected with compressor suction branch pipe.

EFFECT: technical result consists in providing independent operation, as well as increasing range and accuracy of cooling temperature control.

4 cl, 1 dwg

Description

The invention relates to medical equipment, namely, devices for external cooling of pathological human tissues and can be used in cryosurgical operations.

The invention is intended for low-temperature ablation of biological tissues on the surface of human skin. The therapeutic effect is achieved due to local exposure to a tip cooled to low temperatures on undesirable formations on the skin surface. With this effect, the tissues of unwanted formations are destroyed.

Currently, 2 types of apparatuses are used in clinical practice for the implementation of this procedure: apparatuses using the energy of phase transformation, and apparatuses using the effect of gas throttling.

The use of the phase transformation energy effect is based on the absorption of heat that occurs when the state of aggregation of the refrigerant changes (the transition from the liquid state to the gaseous state and the transition from solid to liquid state). The minimum temperature of the working part of the cryotool in this case is maintained close to the boiling point of the refrigerant or its melting point. A system using these principles is described in WO 2010117945 A1 (Publication: 10/14/2010) and US Pat. No. 8,814,850 B2 (Publication: 08/29/2014).

The second type of apparatus in which cooling occurs due to gas throttling. The principle of operation of such devices is that compressed gas at high pressure enters the recuperative heat exchanger, where it is cooled by heat exchange with a colder return flow. After this, direct flow throttling occurs - a sharp decrease in pressure as the gas passes through the narrowed opening. A system using these principles is described in application US 20070277550 A1 (Publication: December 6, 2007).

The main disadvantages of the above devices are:

- the need for the constant presence of a cryoagent or cylinders with gas under pressure for cryosurgical operations;

- the complexity of ensuring the supply of liquid cryoagent and gas cylinders under pressure to remote regions;

- the danger of working with high pressure cylinders and liquid cryoagent;

- the need for constant refueling of the apparatus, which limits the time of continuous cryodestruction of biological tissues.

To avoid these drawbacks, an apparatus for treating cold is proposed, operating on a closed single-threaded refrigeration cycle on a multicomponent mixed refrigerant. Such cycles are known and are used to obtain low temperatures in the range from minus 40 to minus 170 ° C, but have not yet been widely used in cryosurgery.

A known system operating on a mixed refrigerant, which is designed to cool external objects, including biological (US 6151901 A, publication: 11.28.2000), which includes a compressor, a plate heat exchanger, a device for expanding gas and a metal rigid catheter. The system operates as follows. The gas mixture is compressed in the compressor, then enters the miniature plate heat exchanger, where the high-pressure stream is cooled by the low-pressure stream. Then the flow of refrigerant expands in the throttle device, and then cools the heat transfer element of the rigid catheter for further cooling of external objects.

The above system does not provide pressure and flow control of the refrigerant through the evaporator, so there is no possibility of regulating the cooling temperature, which is achieved on the heat transfer element of the rigid catheter. The disadvantages include the presence of high pressure inside the rigid catheter, which is in contact with the patient.

The claimed invention allows to eliminate the disadvantages of the prior art. The technical result is to increase the autonomy of the apparatus, improve performance in terms of increasing the range and accuracy of regulation of the cooling temperature, simplicity and safety of operation. Also, the technical result is to reduce the time the tip reaches the required low temperature, due to the fact that in the process of entering the mode, it is possible to change the pressure of the mixed refrigerant in the evaporator, and thus ensuring the most optimal operating mode of the device during the period until the temperature in the evaporator reaches the set value .

To achieve the claimed technical results, a set of technical problems is solved. All elements of the refrigeration machine operating in a cycle on a mixed refrigerant are located in a separate aggregate unit. An electronic expansion valve that allows you to control the pressure and flow rate of the mixed refrigerant through the evaporator is also located in the aggregate unit. The evaporator of the chiller is a thin tube coil in which the refrigerant is throttled and the temperature lowered. The tip through which the cold is transferred to the fabric to be cooled is a rod of heat-conducting metal, around which a coil-evaporator of the refrigeration machine is wound. The evaporator with a tip lying around the instrumental part of the apparatus for treating cold is connected to its hardware by flexible hoses. The refrigerant pressure in the instrument part does not exceed 3 bar, which allows to ensure complete safety of use of the device. The coil is wound on the tip in such a way that the refrigerant exit from it is closer to the front of the tip, through which cryotherapy is effected on the tissue. Thus, it is possible to provide a lower cryogenic temperature.

Thus, the presence of an electronic expansion valve allows you to adjust the pressure and flow rate of the refrigerant through the evaporator, which in turn determines the cooling temperature. Dividing the system into an aggregate part with a high pressure and a tool part with a low working pressure allows you to reduce tool requirements and ensure safety during operation. The use of an evaporator with a throttling effect ensures the lowest temperature at the tip of the cryo-tip. Forward and return flow connecting hoses can be combined in one, placing them one in the other.

The figure 1 shows a schematic diagram of an apparatus for treating cold, where:

1 - compressor;

2 - trailer refrigerator (air cooling apparatus);

3 - separator;

4 - heat exchanger pre-cooling;

5 - the main heat exchanger;

6 - throttle device;

7 - electronic control valve;

8 - flexible hoses;

9 - evaporator with a throttling effect;

10 - cryo-tip;

Apparatus for treating cold is arranged as follows. Compressor 1, the discharge pipe of which is connected to the inlet pipe of the air cooling apparatus 2. As a compressor, a typical serial piston sealed compressor or a different type of compressor can be used. Next, the air cooling apparatus 2, which is a tubular fin heat exchanger equipped with a fan, is connected to a separator 3, in which the refrigerant vapor pipe is connected to the inlet of the pre-cooling heat exchanger 4, the liquid pipe is connected to the throttle device 6, which, in turn, is connected to the input the low pressure of the heat exchanger 4. The high pressure output of the pre-cooling heat exchanger 4 is connected to the high pressure input of the main heat exchanger 5. Next, the high-pressure output of the main heat exchanger 5 is connected to an electronic expansion valve 7, which is connected through a flexible hose 8 to the evaporator with the effect of throttling 9. The evaporator with the effect of throttling 9 is wound on the cryo-tip 10, the outlet of the evaporator is located at the tip of the cryo-tip. The outlet of the evaporator 9 through a flexible hose 8, which is a metal sleeve with heat insulation, is connected to the low pressure input of the main heat exchanger 5, the output of the heat exchanger 5 is connected to the inlet of the heat exchanger 4, the output of the pre-cooling heat exchanger 4, in turn, is connected to the suction pipe compressor 1. The device is controlled by a microprocessor type programmable control unit, in particular, the electronic control valve 7 is controlled in The dependence of temperature krionakonechnika flexible hose 10. The insulation 8 may be a bill from synthetic materials, and may be screen-vacuum. It is also possible that the hoses are mounted one in the other in order to reduce the heat transfer area and increase the insulation efficiency.

Apparatus for treating cold works as follows.

The mixed refrigerant vapor is compressed in the compressor 1 and pumped into the air cooling apparatus 2, where the heat of compression is removed from the refrigerant. During cooling in the air-cooling apparatus 2, the refrigerant partially condenses and then enters the separator 3, where the vapor phase leaving the upper part of the separator enters the high-pressure input of the pre-cooling heat exchanger 4. The liquid phase leaving the lower part of the separator 3 expands in the throttle device 6, and is fed to the low pressure input of the pre-cooling heat exchanger 4, where it is mixed with the low pressure reverse flow. The high-pressure stream leaves the pre-cooling heat exchanger 4 and enters the main heat exchanger 5, where it condenses completely, then the flow expands in the electronic expansion valve 7, which regulates the flow of refrigerant through the evaporator 9. The refrigerant after valve 7, passing through the flexible hose 8, enters an evaporator with a throttling effect 9, in which it is throttled along the length of the evaporator and reaches the lowest temperature at the outlet of it. The refrigerant, passing through the evaporator 9, cools the cryo-tip 10, and through the flexible hose 8 it enters the low pressure input of the main heat exchanger 5, and then the pre-cooling heat exchanger 4. After the refrigerant enters the suction in compressor 1 and the cycle repeats.

Thus, the apparatus allows to provide the claimed technical results. The device is manufactured industrially from standard devices and devices, is easy to maintain and operate, has optimal weight and size characteristics.

Claims (6)

1. The apparatus for treating cold, including a compressor, heat exchangers, a device for expanding gas and an air cooling apparatus, characterized in that it consists of hardware and tool parts, wherein the hardware includes a series-connected compressor, the discharge pipe of which is connected to the inlet of the air-cooling apparatus, a tubular fin heat exchanger equipped with a fan, which is connected to a separator, the refrigerant vapor pipe of which is connected to the inlet of the pre-cooling heat exchanger, and the liquid pipe is connected to throttle device connected to the low pressure input of the pre-cooling heat exchanger, high output one precooling heat exchanger unit connected with the input pressure of high pressure the main heat exchanger, the high pressure output is connected to an electronic expansion valve which via a flexible hose connected to the evaporator with the effect of throttling; the instrument part includes a cryo-tip, on which an evaporator with a throttling effect is wound so that the evaporator exit is located at the tip of the cryo-tip, while the output of the evaporator with a throttling effect through a flexible hose is connected to the low pressure input of the main heat exchanger, the output of which is connected to the input of the preliminary heat exchanger cooling, the output of which, in turn, is connected to the compressor suction pipe. 2. The apparatus according to claim 1, characterized in that a sealed piston compressor is used as a compressor. 3. The apparatus according to claim 1, characterized in that the flexible hoses are metal hoses with thermal insulation, while for flexible hoses, laid on thermal insulation made of synthetic materials or screen-vacuum thermal insulation is used. 4. The apparatus according to claim 1, characterized in that the flexible hoses are mounted one in the other.

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