RU2366357C2 - Sphygmomanometer cuff assembly, press mould and method for making thereof - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: inventions concern medicine. The sphygmomanometer cuff assembly consists of two volcanite layers attached together to form a hollow casing and have two openings within attachment face. Mostly, the layer attachment is seamless wherein the openings are formed. There are disclosed a press mould used to make said cuff and comprising two boards, a plate and two cap screws, spaced between plates, and method for making this cuff.

EFFECT: improved strength, reliability and service life of the cuff.

11 cl, 5 dwg

Description

The invention relates to the medical industry, and in particular to devices for measuring blood pressure, means and methods of manufacturing such devices.

The traditional device for measuring blood pressure is the Riva-Rocci-Korotkov sphygmomanometer. It contains a hollow cuff connected to a device for pumping air (for example, a rubber bulb) and a manometer (mercury, switch or digital). To measure pressure, the cuff is wrapped around the shoulder (in some devices around the wrist) of the patient and inflated. When inflating, the cuff squeezes the shoulder and the manometer shows the amount of pressure in the cuff at the time of the disappearance and appearance of the pulse. In some modern devices, instead of a rubber bulb, a portable electric pump is used to pump air.

From the foregoing, it is obvious that the cuff of such a device must have high strength, reliability and durability. So, according to the requirements of the Ministry of Health of the Russian Federation, the cuff must withstand 120 thousand inflation cycles, while maintaining air tightness.

Known cuff sphygmomanometer made of two layers of material. Such a cuff and a method for its manufacture are described in US patent No. 6245023 from 06/12/2001, MKI ⁷ A61B 05/00. As indicated in the description (column 3, lines 31-33), these layers can be made of a polymer film glued or welded onto a fabric. The layers are glued to each other along the edge to form an airtight cavity. In this case, the tube connecting the cuff with the device for pumping air is inserted between the layers (column 3, lines 57-59).

Taking into account the high requirements for the cuffs of the sphygmomanometer, the cuff made in this way does not have sufficient strength, reliability and durability due to the fact that the layers are interconnected along the seam, as well as due to insufficiently reliable fastening of the tube connecting the cuff with a device for pumping air. In addition, the manufacturing process of the cuff in this way is not technologically advanced due to the large number of operations.

The solution could be the implementation of a hollow cuff of two superimposed layers of non-vulcanized rubber compound, the edges of which are joined during vulcanization under pressure in the mold. In this case, the cuff is made in the form of an airtight cavity as a whole product with a minimum number of seams or their absence. This approach allows for greater strength, reliability and durability than welding or gluing. However, the strength, reliability and durability of such a product are still insufficient due to the fact that a seam is formed at the point of attachment of the aforementioned tubes (manufactured separately) to the cuff.

In addition, the inner surface of the cuff during curing can stick together, so that it becomes unusable. Release agents are commonly used to prevent such adhesion. As indicated in the description of the patent of the Russian Federation No. 21588746 dated 10.11.2000, MKTU C09D 183/04, B29C 33/64, release agents are "both chemically inert with respect to rubber compounds (talc, chalk) and active (naphthalene in the form of thin powder). " Talc due to its effectiveness and cheapness can be considered the most common release agent used in the manufacture of rubber shells. However, in view of the requirements imposed by the Ministry of Health of the Russian Federation for cuffs of the sphygmomanometer, using talcum powder to prevent adhesion of the inner surfaces of the cuff during vulcanization is not possible, since this powder remains in the cuff cavity and can damage sensitive equipment for measuring pressure and / or patient health.

Thus, to date, it has not been possible to create a cuff that, on the one hand, would have high strength, reliability and durability, and on the other hand, would not harm the equipment for measuring pressure and the health of the patient.

Also known is a mold for manufacturing rubber technical products, comprising two plates equipped with symmetrical recesses facing each other. Such a mold is described, for example, in the book Application of rubber technical products in the national economy. Reference manual. / Ed. D.L. Fedyukina. - M.: Chemistry, 1986, p. 110, Fig. 3.22 (a) and (b). Such a press foma does not allow to manufacture a cuff of the sphygmomanometer that meets the above requirements.

The objective of the invention is the creation of a cuff for the sphygmomanometer, which has high strength, reliability and durability and does not harm the equipment for measuring pressure and patient health, development of a mold for its manufacture and development of a method for manufacturing such a cuff.

The problem is solved in that in the cuff of the sphygmomanometer, made in the form of a solid product from two layers of material that are interconnected to form a hollow shell and in the connection zone of which at least one hole is formed, vulcanized rubber is used as the material, and part of the connection layers made seamless, and it is in this part that a hole is formed.

Due to the fact that part of the connection of the layers is made seamless, the strength, reliability and durability of such a connection, and hence the entire cuff is increased. In addition, it is obvious to a person skilled in the art that fastening a tube connecting the cuff to an air injection device or pressure gauge in a hole formed in a seamless joint is more reliable than fastening such a tube in a hole formed in a seam. Therefore, the most important advantage of the proposed cuff is that the hole for installing the tube connecting the cuff to the air injection device and the pressure gauge is formed in the seamless part of the layer connection.

The cuff can be made in the shape of a rectangle, while the connection of layers along the three sides of the rectangle can be made seamless, and two holes are formed. Thus, a large part of the connection of the layers is seamless, so this option is most preferable in terms of cuff strength. The presence of two holes allows you to install two tubes in the cuff: one for connecting to a device for pumping air, and the other for connecting to a manometer.

The problem was also solved by the fact that in the mold for the manufacture of a hollow cuff of the sphygmomanometer, including two plates equipped with symmetrical recesses facing each other, each plate has a flat recess extending to the edge of the plate and at least one semicircular recess adjacent to it to the other edge of the plate, while the mold also contains a plate and at least one plug of circular cross section, and these plates, plate and plug are made so that when connecting the plates, the plate may be with a gap m is installed in a cavity formed by flat recesses of both plates, and the plug can be installed with a gap in a round cavity formed by semicircular recesses of both plates, while the plug is in contact with the plate.

As a rule, flat recesses and, accordingly, the cavity formed by them have a rectangular shape. In this case, the plates, respectively, also have a rectangular shape.

In a preferred embodiment, the edge of the plate to which the flat recess reaches, and the edge of the plate to which the semicircular recesses extend, are mutually perpendicular to each other.

The rectangular shape of the slabs is usually such that the sides of the rectangular slab have different lengths, with the edge of the slab reached by a flat recess located on the short side of the slab.

As a rule, each plate has another semicircular recess located next to the first. This allows you to form two holes in the cuff: one for connecting to a device for pumping air, and the other for connecting to a manometer.

The problem is also solved by the fact that when implementing the method of manufacturing the cuff of the sphygmomanometer, including placing in the above mold unvulcanized rubber mixture, the plate molds are connected under pressure, while the plate is installed in the cavity formed by flat recesses of both plates, the plug is installed in a round the cavity formed by the semicircular recesses of both plates, and also set in contact with the plate, and in the gap between the plate and the plug on one side and the plates on the other side, size schayut rubber composition is heated slab to a temperature required for the vulcanization, so that the rubber composition is vulcanized in the gap, the plate is removed from the thus formed sleeve through the opening and then the opening is sealed.

As a rule, an unvulcanized rubber mixture is formed in two layers and a plate is placed between these layers, so that during vulcanization between these layers a seamless connection is formed with the holes formed at the location of the plug, while the hole is formed by a part of the edge of the layers, which remains unconnected, and close up this hole by connecting layers along this edge.

The connection of the part of the edge of the layers remaining unconnected can be accomplished by placing a strip of unvulcanized rubber mixture between these layers along their edge and curing this strip.

Tubes are then installed in the formed openings connecting the cuff with the air injection device and the pressure gauge. These tubes, usually made of rubber, are selected so that the outer diameter of the tube corresponds to the diameter of the hole. The tubes are installed in any known manner, for example, glued.

The following is a detailed description of an example embodiment of the invention with reference to the accompanying drawings, in which:

figure 1 depicts a side view in section, made along the axis of the semicircular part of the recess of the mold with disconnected plates;

figure 2 depicts a side view in section in the same axis as in figure 1, the mold with connected plates;

figure 3 depicts a section along the line 3-3 in figure 2;

figure 4 depicts a top view of the bottom plate of the mold;

5 is a perspective view of a finished cuff of a sphygmomanometer made according to the invention.

As shown in figures 1, 2, and 3, the proposed mold for the manufacture of a hollow cuff of the sphygmomanometer includes two rectangular metal plates: the lower plate 1, which serves as the mold matrix, and the upper plate 2, which serves as the cover of the mold. The plate 1 has a flat recess 3, which, as can be seen from Figs. 3 and 4, reaches the short edge 4 of the plate 1. As most clearly shown in Fig. 4, two identical semicircular recesses 5 of variable section adjoin the recess 3, each of which comes to another, long, edge 6 of the plate, perpendicular to the edge 4.

Plate 2 is made with recesses facing the recesses of plate 1 and symmetrical with them, and therefore not described in detail here. The mold also contains a plate 7, the shape of which is such that when connecting the plates, the plate 7 can be installed with a gap in the cavity formed by the flat recesses of both plates 1 and 2, as shown in Fig.2. In addition, the mold contains two identical plugs 8 of circular cross section, the shape of which is such that each plug can be installed with a gap in a circular cavity formed by semicircular recesses of both plates, while the plate 7 is in contact with the plugs 8, as shown in figure 2.

The plug 8 has the following parts, made in it in one piece: a rod 9, designed to form a hole for installing a tube connecting the cuff with a device for pumping air or a manometer, a shoulder 10, designed to position and fix the plug in the round cavity of the mold, and pen 11.

The manufacture of the cuff of the sphygmomanometer using the described mold occurs in the following sequence. When the plates 1 and 2 are connected under pressure, an unvulcanized rubber mixture formed in the form of two layers 12 and 13 is placed between the plates 1 and 2. A plate 7 is placed between these layers and the plugs 8 are placed in contact with it. This contact is necessary in order to ensure that the cuff cavity formed by the plate 7 communicates with the hole formed by the plug 8. The plate 7 is installed in the cavity formed by the flat parts of the recesses of the plates, and the plugs are installed in two circular cavities formed by the semicircular parts of the recesses of the plates. In this case, the rubber mixture is placed in the gap between the plate and the plugs on one side and the plates on the other side.

The vulcanization process is carried out by heating the plates to a vulcanization temperature. Due to the high temperature and pressure, the viscous rubber mixture is evenly distributed in the gap. Thus, during vulcanization of the rubber compound in the gap between the layers 12 and 13 along their edge, a seamless connection is formed. At the same time, holes 14 and 15 are formed in the location of the plugs for installing tubes connecting the cuff to the air injection device and pressure gauge (see Fig. 5). However, part of the edge of the layers at the place where the flat recess reaches the other edge of the plates remains unconnected, since at the edge 4 of the plate, the plate 7 prevents them from joining, as can be seen from figure 3. At the end of vulcanization, the plates 1 and 2 are disconnected and the plate 7 is removed through the part of the edge of the layers that remains unconnected.

In the resulting rectangular blank, in which the layers 12 and 13 on three sides are connected by a seamless connection, it remains only to connect the fourth side remaining unconnected. This connection is carried out by placing between the layers along their edge a strip of unvulcanized rubber compound and curing this strip, for example, by clamping this edge between two flat heated surfaces. The resulting connection is also very strong, although less durable than the seamless connection, which connects the other three sides of the rectangular cuff. However, the most important advantage of the proposed cuff is that the holes for installing tubes connecting the cuff to the air injection device and the pressure gauge are formed in the seamless part of connecting the layers 12 and 13 together with the cuff. This provides a more durable and reliable fastening of these tubes in these holes. It should be noted that the described method of connecting the part remaining unconnected after removing the plate is not essential from the point of view of the technical result achieved by the invention. Along with this method, any other known method can be used that provides a strong and reliable connection.

In the formed openings 14 and 15, tubes are then installed connecting the cuff with the air injection device and pressure gauge (not shown). These tubes, as a rule, are also made of rubber and are selected so that the outer diameter of the tube corresponds to the diameter of the hole. The tubes are installed in any known manner, for example, glued or through a rigid cylindrical adapter.

To increase comfort when the patient comes in contact with the cuff, it can be covered with tissue on at least one side. This coating can be done in a variety of ways - from gluing a fabric strip to performing a cuff with a fabric cover.

Claims (11)

1. The cuff of the sphygmomanometer made of vulcanized rubber in the form of a hollow shell having the shape of a rectangle of two layers, the three sides of the shell are connected without seam formation during vulcanization, and the fourth side is connected using a strip of unvulcanized rubber, while the hole for installing the tube is made in parts of the seamless connection of the sides of the rectangle. 2. The cuff according to claim 1, characterized in that a second hole for mounting the tube is formed therein. 3. A mold for the manufacture of a cuff of the sphygmomanometer, comprising two plates equipped with symmetrical recesses facing each other, characterized in that it contains a plate and at least one circular plug, each plate has a flat recess extending to the edge of the plate and at least one adjacent semicircular recess extending to the other edge of the plate, the plate is made with the possibility of installation with a gap in the cavity formed by flat recesses of the plates, and the plug with the possibility of installation with a gap in the round floor STI formed by semicircular recesses on both plates and thus the possibility to be in contact with the plate. 4. The mold according to claim 3, characterized in that the flat recesses and accordingly the cavity formed by them have a rectangular shape. 5. The mold according to claim 4, characterized in that the plates have a rectangular shape. 6. The mold according to claim 5, characterized in that the edge of each plate to which the flat recess reaches, and the edge of the plate to which the semicircular recess reaches, are perpendicular to each other. 7. The mold according to one of claims 4, 5 or 6, characterized in that the edge of the rectangular plate, to which the flat recess reaches, is located on the short side of the plate. 8. The mold according to one of paragraphs.4, 5 or 6, characterized in that each plate has another semicircular recess located next to the first. 9. A method of manufacturing a cuff of a sphygmomanometer, comprising placing an unvulcanized rubber mixture in a mold, characterized in that the mold is performed according to claim 3, the mold plates are joined under pressure, and the plate is installed in a cavity formed by flat recesses of the plates, the plug is installed in a circular cavity formed by semicircular recesses of the plates in contact with the plate, the rubber mixture is placed in the gap between the plate and the plug on the one hand and the plates on the other hand, the plates are heated to the temperature of the volcano rubberization in the gap, remove the plate from the thus formed cuff through the hole, which is then closed. 10. The method according to claim 8, characterized in that the unvulcanized rubber mixture is formed in the form of two layers and a plate is placed between these layers with the formation of vulcanization between these layers along their edge seamless connection with holes formed at the location of the plug, while the hole form part of the edge of the layers, which remains unconnected, and close this hole by connecting the layers along this edge. 11. The method according to claim 10, in which the connection of the part of the edge of the word, remaining unconnected, is carried out by placing between these layers along their edge a strip of unvulcanized rubber compound and vulcanization of this strip.

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