RU2029532C1 - Device for local contact hypothermia - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: this device for local contact hypothermia includes external hermetically sealed envelope made of transparent flexible film, water container and device for its disintegration, both being enclosed in this envelope, main granulated inorganic salt fraction and auxiliary one which contains particles smaller than those of main fraction. Ratio between sizes of particles of main and auxiliary fractions lies within range of 4 to 10 and ratio of auxiliary to main fractions is 8 to 12 %. EFFECT: longer service life. 2 cl, 2 dwg

Description

 The invention relates to medicine, namely to devices for local contact hypothermia of the human body in order to reduce the necrosis zone, reduce the inflammatory response in tissues, prevent or relieve heat stroke and other similar purposes.

 Known devices for local contact hypothermia containing a sealed bag filled with an inorganic salt, such as ammonium nitrate. The bag contains a container with water and a device for its destruction. When using the device, the container is opened and the package is applied to the cooled area of the body. After the container is destroyed, the water is mixed with salt, and the packet is cooled during the endothermic reaction that accompanies the dissolution of the salt.

The main disadvantage of such devices is the short duration of action - a consequence of the transience of the endothermic reaction between water and salt. The following agents are used to prolong the reaction:
I. Successive dissolution of portions of salt.

 II. Regulation during the reaction of the contact surface of water and salt.

 III. The use of salts in granular form with soluble or porous shells of granules.

 The constructions of the first type are realized in the form of multi-tiered vessels in which the compartments for mixing salt and water are connected in series so that the solution from the upper vessel is drained into the mixing compartment below, etc. Later devices of this type used several containers with water placed in a container with salt or several containers with salt in a bag filled with water. In the process of using the devices, successive destruction of the containers was carried out, by which the prolongation of cooling was achieved.

 Devices of the second type are the least diverse. They usually have a shaped container with salt. Due to this, the contact area of water and salt changes during dissolution. In another embodiment, the salt is placed in a container with permeable side walls. The reaction rate in this design can be adjusted by changing the immersion depth of the container during the dissolution of the salt.

 In devices of the third type, granular salt is used, and in order to increase the cooling time, in some cases, the coating of granules with a water-soluble substance is used. In other cases, porous shells of granules that swell when wet are used for the same purpose.

 Sometimes, to prolong the cooling, heat-accumulating substances (for example, sand), devices to reduce the heat exchange of the reaction zone with the environment, are used.

 Designs of type I and II are difficult, in most cases it is impossible to use for the purposes of superficial hypothermia in medicine. In addition, they do not provide the required cooling duration for use in this area. Type 3 devices are easy to use. Porous shells give the longest known reaction time. However, the cost of salts with porous shells of granules is very high, the duration of cooling remains insufficient. In addition, the reaction products contain toxic and difficult to destroy substances, such as polymeric shell materials.

 Closest to the present invention in essence and in combination of features is a device for local contact hypothermia described in UK patent N 2233081. This device contains an external sealed bag of transparent elastic film placed in a bag container with water, having a device for its destruction and granular inorganic salt consisting of a main fraction and an additional fraction with smaller particles. The patent, with regard to endothermic reactions, contains only the idea of prolonging them by initially dissolving the predominantly small fraction and then the larger one. However, there is no optimal ratio of mass and dispersion of fractions in the indicated analogue and therefore, according to the materials of the patent, it is impossible to solve the main problem of such devices - achieving the required cooling duration.

 The aim of the present invention is to increase the duration of the endothermic reaction that occurs when the salt is dissolved in water while minimizing the toxicity of the final products of this reaction.

 This goal is achieved in that the ratio of the particle sizes of the main and additional fractions is in the range of 4-10, and the mass ratio of the additional and main fractions is 8-12%.

 The invention is illustrated in the drawing, where figure 1 shows a view of the device in plan; figure 2 is a transverse section of the device.

 A device for local contact hypothermia consists of a sealed bag 1 made of an elastic transparent film. A granular inorganic salt 5, for example, ammonium nitrate, a container 3 with water and a device 4 for destroying the container 3, is placed in the bag 1. This device is, for example, in the form of a pointed rod. The package 1 can be enclosed in a transparent protective shell 2, which guarantees that the reaction products do not leak out. Granules of salt 5 consist of a main fraction and an additional fraction, and the particle size of the main fraction is 4-10 more than the additional, and the mass ratio of the additional and main fractions is 8-12%.

 The device is used as follows.

 Using the device 4, the container 3 is destroyed, after which the device is superimposed on the cooled area of the body. The water flowing out of container 3 moves with salt, an endothermic reaction occurs, and the body is cooled by heat removal to the reaction zone through the walls of packet 1 and shell 2.

 The experiments showed that with the indicated ratio of mass and particle size of fractions, the longest endothermic reaction is ensured. At the same time, minimal toxicity of the reaction products is achieved, which facilitates their neutralization and destruction.

Comparative tests of the present invention and the cooling package similar purpose known company Johnson and Johnson showed that the time to reach a solution temperature of 10 ± 1 ^{° C} from the time of mixing at a temperature of ²⁰ ° C is: y packages "Ldinka", made in accordance with the invention, - no less than two hours; for Johnson and Johnson packages - 1 h 40 min.

Claims (2)

 1. DEVICE FOR LOCAL CONTACT HYPOTHERMIA, containing an external sealed bag of transparent elastic film, a water container in a bag with a device for its destruction, and a granular inorganic salt, including the main fraction and an additional one with particles smaller than the main fraction, characterized in that the ratio of particle sizes of the main and additional fractions is in the range of 4 - 10.  2. The device according to claim 1, characterized in that the ratio of additional to the main fraction is 8 - 12%.

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