WO2018193823A1 - Bag-shaped structure, cuff, and sphygmomanometer - Google Patents

Abstract

Provided is a bag-shaped structure having excellent flexibility and high creep resistance. The present invention provides a bag-shaped structure (22) that includes an inner wall (221) and an outer wall (222) that faces the inner wall (221), wherein at least one of the inner wall (221) and the outer wall (222) includes a sheet comprising a silicone resin which has a Shore A hardness in the range of 10 to 75 and a tensile elongation at break of 1000% or more. The present invention also provides a cuff for a sphygmomanometer and a sphygmomanometer which include the bag-shaped structure (22).

Description

Bag-like structure, cuff and blood pressure monitor

The present invention relates to a bag-like structure, a cuff, and a blood pressure monitor.

In the measurement of blood pressure, for example, a cuff is wrapped around the upper arm or wrist, the bag-like structure included in the cuff is inflated, and then the internal pressure of the bag-like structure is reduced. The systolic blood pressure and the diastolic blood pressure are determined based on changes in the pulse wave and Korotkoff sound that occur in the process of decreasing the internal pressure.

Recently, in order to improve the portability and usability of the sphygmomanometer, it is desired to reduce the sphygmomanometer. Accordingly, there is a demand for narrowing the bag-like structure used for the cuff of a sphygmomanometer. However, when the bag-like structure is narrowed, there is a problem that the variation in pulse wave measurement values tends to increase because the vascular compression area decreases.

JP 2017-6488 describes a sphygmomanometer in which a cuff includes one or two fluid bags. The fluid bag contained in the cuff forms a first fluid bag region at a position corresponding to the half surface on the artery side of the outer peripheral surface of the measurement site when the cuff is attached to the measurement site such as a wrist. At the same time, the second fluid bag region is formed at a position corresponding to the opposite half surface. When the cuff is attached to a measurement site such as a wrist and the fluid is supplied to the fluid bag, the second fluid bag region has a larger stroke than the first fluid bag region. A configuration that expands in quantity is adopted.

For example, Japanese Patent Application Laid-Open No. 2017-6488 describes that the following configuration may be employed in a portion of the fluid bag forming the second fluid bag region. That is, among the sheets forming the bag-like structure in this portion, the hardness of the pair of first sheet portions corresponding to the side portions of the bag-like structure is determined by measuring the hardness of the first sheet portion far from the measurement site. It is made smaller than the hardness of the 2nd sheet part which connects. For example, a silicone resin having a hardness of 50 degrees is used as the material for the first sheet portion, and a polyurethane resin having a hardness of 80 degrees is used as the material for the second sheet portion.

When the bag-like structure having such a configuration is inflated, the movement of the artery between the long palmar flexion tendon and the ribs or between the superficial digital flexor tendon and the ulna is suppressed, and extra pressure is applied to crush the artery. The amount is unnecessary. For this reason, the blood pressure measurement value can be brought close to a true value.

When a bag-like structure is made of a flexible material, creep deformation is likely to occur due to repeated expansion. In particular, in the part of the bag-like structure where the base of the blood pressure monitor or the living body surface does not come into contact, the bag-like structure is over-expanded when the bag-like structure is inflated, and the amount of creep deformation is larger than other parts. easy. In addition, creep destruction due to creep deformation is likely to occur at the bonded portion between the sheets. When sagging or tearing of the bag-like structure due to such creep deformation occurs, it becomes difficult to perform highly accurate measurement.

An object of the present invention is to provide a bag-like structure having excellent flexibility and high creep resistance.

According to the first aspect of the present invention, an inner wall portion and an outer wall portion facing the inner wall portion are provided, and at least one of the inner wall portion and the outer wall portion has a Shore A hardness of 10 to 75 and A bag-like structure including a sheet made of a silicone resin having a tensile elongation at break of 1000% or more is provided.

Here, the tensile elongation at break is a cutting obtained by conducting a tensile test on a dumbbell-shaped No. 3 specimen as defined in JIS K6251: 2010 (“vulcanized rubber and thermoplastic rubber—how to obtain tensile properties”). Also, Shore A hardness is a type A specified in JIS K6253-3: 2012 ("Vulcanized rubber and thermoplastic rubber-Determination of hardness-Part 3: Durometer hardness"). This is the durometer hardness obtained by the durometer hardness test.

According to the second aspect of the present invention, there is provided a bag-like structure according to the first aspect, wherein the thickness of the sheet is in the range of 0.10 mm to 0.60 mm.
According to a third aspect of the present invention, there is provided the bag-like structure according to the first or second aspect, wherein the silicone resin has a Shore A hardness in the range of 15 to 70.
According to the fourth aspect of the present invention, there is provided a cuff including the bag-like structure according to any one of the first to third aspects so that at least a part of the sheet is located on the living body side when the bag-like structure is attached. Is done.
According to the 5th side surface of this invention, the blood pressure meter provided with the cuff which concerns on a 4th side surface is provided.

According to the first aspect, the bag-like structure includes an inner wall portion and an outer wall portion facing the inner wall portion, and at least one of the inner wall portion and the outer wall portion has a Shore A hardness in the range of 10 to 75. And a sheet made of a silicone resin having a tensile elongation at break of 1000% or more. Such a sheet has high creep resistance despite being flexible. Therefore, according to the first aspect, it is possible to achieve both high creep resistance and excellent flexibility.

According to the second aspect, since the thickness of the sheet is in the range of 0.10 mm to 0.60 mm, the risk of tearing is small. For example, when a bag-like structure is used for a cuff, Particularly excellent arterial occlusion properties can be obtained.

According to the third aspect, since the silicone resin has a Shore A hardness in the range of 15 to 70, particularly excellent creep resistance can be achieved.

According to the fourth aspect, when the bag-like structure according to any one of the first to third aspects is mounted, the sphygmomanometer cuff includes such that at least a part of the sheet is positioned on the living body side. Therefore, it is possible to achieve both high creep resistance and excellent arterial occlusion characteristics.

According to the fifth aspect, since the cuff according to the fourth aspect is used in the sphygmomanometer, in addition to achieving high durability, it is possible to measure the blood pressure value with high accuracy.

FIG. 1 is a perspective view schematically showing a sphygmomanometer according to an embodiment of the present invention. 2 is a cross-sectional view schematically showing a bag-like structure included in the blood pressure monitor shown in FIG. FIG. 3 is a cutaway perspective view schematically showing a bag-like structure included in the sphygmomanometer shown in FIG. 4 is a cross-sectional view schematically showing a state in which a cuff included in the sphygmomanometer shown in FIG. 1 is attached to a living body. FIG. 5 is a cross-sectional view schematically showing a state similar to FIG. 4 except that the bag-like structure included in the cuff is expanded. FIG. 6 is a graph showing an example of creep deformation associated with repeated use. FIG. 7 is a perspective view schematically showing an example of breakage that may occur at the joint portion of the bag-like structure due to creep deformation. FIG. 8 is an enlarged view schematically showing the structure of the sheet forming the bag-like structure according to the embodiment of the present invention. FIG. 9 is an enlarged view schematically showing the structure of the sheet according to the comparative example. FIG. 10 is a stress strain diagram of a sheet that can be used for a bag-like structure according to an embodiment of the present invention and a sheet that can be used for a bag-like structure according to a comparative example. FIG. 11 is a cross-sectional view schematically showing a modification of the bag-like structure shown in FIGS. 12 is a cutaway perspective view schematically showing the bag-like structure shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the element which has the same or similar function, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

<Sphygmomanometer>
FIG. 1 is a perspective view schematically showing a sphygmomanometer according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a cuff included in the sphygmomanometer of FIG.

A sphygmomanometer 1 shown in FIG. 1 is an electronic sphygmomanometer attached to a living body, specifically, a wrist. The sphygmomanometer 1 may be attached to another part of the living body.
The sphygmomanometer 1 includes a device main body 11 and a cuff 20.

The apparatus body 11 includes a case 111, a display unit 112, an operation unit 113, a flow path (not shown), a pump 114, a valve 115, a pressure sensor 116, a power supply unit 117, and a control unit 118. It is out.

The case 111 has openings for the display unit 112 and the operation unit 113 in the upper part. Here, the case 111 is an integral part of the base material 121 of the cuff 12, which will be described in detail later. The case 111 may be a separate component from the base material 121.

The display unit 112 is installed in the case 111 so as to display an image at the position of the opening provided in the upper part thereof. The display unit 112 is, for example, a liquid crystal display or an organic electroluminescence display. The display unit 112 displays various types of information including blood pressure values such as maximum blood pressure and minimum blood pressure, and measurement results such as heart rate.

The operation unit 113 has buttons for the user to start / stop measurement, turn on / off the power, select a function, make various settings, and the like. The operation unit 113 is installed in the case 111 so that these buttons are exposed to the external space of the case 111 at the position of the opening. The operation unit 113 outputs an electrical signal corresponding to the command or information input via the button. When a touch panel display is used as the display unit 112, it may be used as an operation unit.

The flow path is installed in the case 111. According to an example, the flow path has a structure branched in four directions and has four openings. One of these openings is connected to the intake / exhaust port of the bag-like structure 22 included in the cuff 20.

The pump 114 is installed in the case 111. The exhaust port of the pump 114 is connected to another one of the openings included in the flow path. The pump 114 is, for example, a rolling pump. The pump 114 discharges compressed air from the exhaust port.

The valve 115 is installed in the case 111. The valve 115 is connected to yet another one of the openings that the flow path contains. The valve 115 is a valve whose operation can be controlled using electric power, for example, an electromagnetic valve. The valve 115 opens and closes the opening to which it is attached.

The pressure sensor 116 is installed in the case 111. The pressure sensor 116 is connected to the remaining one of the openings that the flow path contains. The pressure sensor 116 is, for example, a piezoresistive pressure sensor. The pressure sensor 116 detects the pressure in the flow path and outputs an electrical signal corresponding to this pressure.

The power supply unit 117 is installed in the case 111. The power supply unit 117 includes a battery, for example, a lithium ion secondary battery. The power supply unit 117 is electrically connected to the control unit 118. The power supply unit 117 supplies power to the control unit 118.

The control unit 118 is installed in the case 111. The control unit 118 is electrically connected to the display unit 112, the operation unit 113, the pump 114, the valve 115, and the pressure sensor 116.
The control unit 118 includes, for example, a processor (CPU), a primary storage device (RAM), and a secondary storage device (ROM or the like). The secondary storage device stores, for example, a program that is interpreted and executed by the processor. The primary storage device primarily stores, for example, a program stored in the secondary storage device, data generated by arithmetic processing by the processor, and the like. The processor interprets and executes the program stored in the primary storage device. That is, when the control unit 118 executes a program stored in the secondary storage device, the control unit 118 develops the program in the primary storage device. Next, the control unit 118 causes the processor to interpret and execute the program, thereby executing the following processing.
That is, the control unit 118 supplies power to the display unit 112, the operation unit 113, the pump 114, the valve 115, and the pressure sensor 116. Further, the control unit 118 controls operations of the display unit 112, the pump 114, and the valve 115 based on electric signals output from the operation unit 113 and the pressure sensor 116.

For example, when an electrical signal corresponding to the start of measurement is supplied from the operation unit 113, the control unit 118 controls the operation such that the valve 115 is closed and then the pump 114 starts driving. Next, the control unit 118 determines the timing for stopping the operation of the pump 114 based on the electric signal output from the pressure sensor 116, and stops the operation at this timing, and then the valve 115 is gradually opened. To control their operation. Thereafter, the control unit 118 obtains measurement results such as blood pressure values such as systolic blood pressure and diastolic blood pressure and heart rate from the electrical signal output from the pressure sensor 116, and outputs an image signal corresponding to the measurement results to the display unit 112. To do.
The cuff 20 is integrated with the apparatus main body 11. As shown in FIG. 2, the cuff 20 includes a base material 21, a fastener (not shown), a bag-like structure 22, and a bonding layer 23. The cuff 20 may be separate from the apparatus main body 11.

The base material 21 is a low stretchable member having a belt shape. The base material 21 is made of resin, for example. The base material 21 supports the bag-like structure 22 as shown in FIG. 2 and enables the cuff 20 to be wound around the living body as can be seen from FIG. Moreover, the base material 21 suppresses the expansion to the opposite side of the living body without hindering the expansion to the living body side when the bag-like structure 22 is expanded.

Here, the base material 21 is integrated with the case 111 at one end, and the other end is joined to a fastener or the like. As described above, the case 111 and the base material 121 may be separate components. In addition, the base material 21 may be shaped into a shape that is curved along the shape of the part to which the cuff 20 is attached in order to facilitate the attachment of the cuff 20 to the living body.

The fastener allows the other end of the base material 21 to be fixed to the case 111. The fastener is, for example, a three-fold buckle having one end supported by the other end of the base material 21 and the other end supported by the case 111.

The bag-like structure 22 is supported by the base material 21. As described above, the bag-like structure 22 has an intake / exhaust port, and this intake / exhaust port is connected to one of the openings of the flow path included in the apparatus main body 11. The bag-like structure 22 may have an intake port and an exhaust port instead of the intake / exhaust port.

When the pump 114 is driven in a state where the cuff 20 is attached to the living body and the valve 115 is closed, the bag-like structure 22 expands, and as a result, the cuff 20 blocks the living artery. Next, when the driving of the pump 114 is stopped and the valve 115 is opened, the bag-like structure 22 contracts. As a result, the pressure applied to the living body by the cuff 20 is weakened, and the blood flow is resumed. Details of the bag-like structure 22 will be described later.

The bonding layer 23 is supported by the surface of the base 21 that faces the living body when the cuff 20 is attached to the living body. The bonding layer 23 bonds the base material 21 and the bag-like structure 22. The bonding layer 23 is, for example, an adhesive layer or a double-sided pressure-sensitive adhesive tape.

<Bag-like structure>
Next, the bag-like structure 22 will be described in detail with reference to FIGS.
FIG. 3 is a cutaway perspective view of the bag-like structure included in the cuff of FIG.
As shown in FIG. 3, the bag-like structure 22 includes an inner wall portion 221, an outer wall portion 222, and a connection tube 228. The bag-like structure 22 is configured by joining the peripheral portions of the inner wall portion 221 and the outer wall portion 222 with the connection tube 228 interposed therebetween.

The inner wall portion 221 is a portion of the bag-like structure 22 that is located on the living body side when the cuff 20 is attached to the living body. Further, the outer wall portion 222 is a portion of the bag-like structure 22 that is located on the side opposite to the living body side when the cuff 20 is attached to the living body. The inner wall portion 221 is a portion located on the living body side when the cuff 20 is attached to the living body, and may contact the living body or may contact the living body via another member.

The inner wall part 221 and the outer wall part 222 are rectangular and face each other. The length direction of the inner wall part 221 and the outer wall part 222 is the same as the length direction of the base material 21 shown in FIGS. Note that the length directions of the inner wall portion 221 and the outer wall portion 222 may be different from the length direction of the base material 21. However, when the cuff 20 having the same length direction of the inner wall portion 221 and the outer wall portion 222 and the length direction of the base material 21 is used, the length direction of the inner wall portion 221 and the outer wall portion 222 and the base material 21 Compared with the case where the cuff 20 having a different length direction is used, the pressure on the living body becomes more uniform, and the measurement accuracy of the blood pressure value can be further increased.
As described above, the peripheral portions of the inner wall portion 221 and the outer wall portion 222 are joined to each other. As shown in FIG. 2, the outer wall portion 222 is bonded to the base material 21 via the bonding layer 23. In addition, the sheet | seat which comprises the inner wall part 221 and the outer wall part 222 is demonstrated later.

The joining of the inner wall part 221 and the outer wall part 222 shown in FIGS. 2 and 3 can be performed by, for example, a molecular adhesive. When bonded by a molecular adhesive, durability against peeling due to repeated use can be further enhanced.

It is preferable that the bonding width 22a (FIG. 2) for joining the inner wall portion 221 and the outer wall portion 222 is small. For example, when the bag-like structure 22 is used for the cuff 20 having a very narrow width, the adhesive width 22a is preferably in the range of 0.3 mm to 2.5 mm, and preferably 0.5 mm to 1.5 mm. More preferably, it is within the range. When the bonding width 22a is too small, positioning at the time of bonding becomes difficult, and there is a possibility that bonding variation will increase. When the bonding width 22a is too large, the size of the living body compression area becomes insufficient, and there is a possibility that the measurement accuracy is lowered.

The connection tube 228 is fixed between one end in the longitudinal direction between the inner wall portion 221 and the outer wall portion 222. The connection tube 228 allows the fluid passing through the flow path of the apparatus main body 11 shown in FIG. 1 to enter the internal space constituted by the inner wall portion 221 and the outer wall portion 222, that is, the inner space of the bag-like structure 22. The bag-like structure 22 and the flow path are connected.

The bag-like structure 22 includes a silicone resin sheet having a Shore A hardness of 10 to 75 and a tensile elongation at break of 1000% or more. Here, at least a part of the inner wall portion 221 and the outer wall portion 222 is made of the silicone resin sheet. As will be described later, the bag-like structure 22 provided with such a silicone resin sheet can achieve high creep resistance and excellent flexibility.

The tensile elongation at break of the silicone resin sheet is more preferably 1200% or more. The upper limit value of the tensile elongation at break of the silicone resin sheet is not particularly limited, but according to the method for producing a silicone resin sheet described later, the upper limit value of the tensile elongation at break of the silicone resin sheet is, for example, 4000%. When the tensile elongation at break of the silicone resin sheet is too small, the creep resistance becomes low, and there is a possibility that breakage due to creep deformation occurs due to repeated expansion and contraction. In this case, breakage due to creep deformation is likely to occur particularly in the vicinity of the joint portion where the bag-like structure has a large expansion and expansion.

Further, the Shore A hardness of the sheet is more preferably in the range of 15 to 70. When the Shore A hardness of the silicone resin sheet is too small, it becomes difficult to bond the silicone resin sheets to each other, and there is a possibility that a bag-like structure cannot be formed. This is because when the flexibility of the silicone resin sheet is too large, for example, when a molecular adhesive is used for bonding the silicone resin sheets, it is difficult to apply an adhesive pressure to the bonding surface. When the Shore A hardness of the silicone resin sheet is too large, the number of cross-linking points in the silicone resin increases, resulting in a decrease in the molecular weight between the cross-linking points. As a result, the silicone resin sheet has a tensile elongation at break of 1000% or more. Can be difficult to create.

The thickness of the silicone resin sheet is preferably in the range of 0.10 mm to 0.60 mm, and more preferably in the range of 0.15 mm to 0.30 mm. When the thickness of the silicone resin sheet is too small, the strength of the silicone resin sheet is insufficient, and the bag-like structure 22 may easily be abnormally swollen. In this case, a loss of the living body compression pressure may occur, and the measurement accuracy may deteriorate. When the thickness of the silicone resin sheet is too large, the adhesion of the silicone resin sheet to the shape on the living body side is lowered, the blood vessel compression characteristic during blood pressure measurement is hindered, and the measurement accuracy may be deteriorated.

The silicone resin sheet is preferably provided so that at least a part of the silicone resin sheet is located on the living body side when the bag-like structure 22 is attached to the living body. Here, as an example, it is assumed that the inner wall portion 221 and the outer wall portion 222 are silicone resin sheets that satisfy the above-described conditions.

The above-mentioned silicone resin sheet is composed of a silicone resin composition containing an organopolysiloxane and a filler. Below, these components are demonstrated.

[Organopolysiloxane]
As the organopolysiloxane, one containing a reactive functional group is used. As such an organopolysiloxane, for example, reactive functional groups such as an alkenyl group, an amine group, an epoxy group, a carboxyl group, a mercapto group, and a hydrogen group are introduced into the side chain or terminal portion of the organopolysiloxane. Can be used. As the organopolysiloxane containing a reactive functional group, one of these may be used alone, or two or more may be used.

The organopolysiloxane is preferably one having an alkenyl group introduced into the side chain of the organopolysiloxane. Examples of the alkenyl group include a vinyl group, an allyl group, and a butenyl group. As the alkenyl group, a vinyl group is preferable.

When using an organopolysiloxane containing a vinyl group, it is necessary to use a vinyl group having a molar ratio of 0.03% to 5% when the constituent monomer unit of the organopolysiloxane is 100%. It is preferable to use a material in the range of 0.05% to 1%. The molar ratio of the vinyl group affects the tensile elongation at break and the Shore A hardness. For example, when the molar ratio of the vinyl group is increased, the crosslink density of the organopolysiloxane is increased, so that the tensile elongation at break is decreased and the Shore A hardness is increased. Use of an organopolysiloxane containing a vinyl group in a molar ratio within the above-described range is advantageous in obtaining a silicone resin sheet having a tensile elongation at break and a Shore A hardness within the above ranges.

In order to adjust mechanical properties such as Shore A hardness and tensile breaking elongation of the silicone resin sheet, non-reactive functional groups may be introduced together with the organopolysiloxane containing reactive functional groups. Examples of the non-reactive functional group include a methyl group, an ethyl group, a phenyl group, a long chain alkyl group, a polyether group, a fatty acid ester group, and a fatty acid amide group. As organopolysiloxane containing a non-reactive functional group, one of these may be used alone, or two or more may be used.

[Filler]
Silica particles are preferred as the filler contained in the silicone resin composition. In addition, when silica particles are used as the filler, other inorganic particles may be further included.

Known silica particles can be used. The silica particles may be any of those obtained by a wet method and those obtained by a dry method, and are not particularly limited.

The average particle diameter of the silica particles is preferably in the range of 0.01 μm to 3 μm, and more preferably in the range of 0.1 μm to 1 μm. Here, the average particle diameter is an average particle diameter obtained by a dynamic scattering method. Silica particles having an average particle diameter in the above range exhibit high dispersibility in the silicone resin composition.

The amount of silica particles is preferably in the range of 10 to 30 parts by mass, more preferably in the range of 15 to 25 parts by mass with respect to 100 parts by mass of the organopolysiloxane. Use of a silicone resin composition in which the amount of silica particles is in the above range is advantageous in obtaining a silicone resin sheet having a Shore A hardness and a tensile elongation at break within the above ranges.

As the silica particles, it is preferable to use those having a surface modified with a silane cup agent having reactivity with the reactive functional group of the organopolysiloxane. When the surface of the silica particles is modified with a silane coupling agent, the affinity and reactivity with the organopolysiloxane on the surface of the silica particles can be increased.

Examples of the silane coupling agent include alkoxysilane compounds, chlorosilane compounds, acyloxysilane compounds, silanol compounds, and silazanes. As the silane coupling agent, one of these may be used alone, or two or more may be used. As the silane coupling agent, an alkoxysilane compound, specifically, vinyltrimethoxysilane or vinylethoxysilane is preferably used.

The amount of the silane coupling agent is preferably in the range of 10 to 80 parts by mass and more preferably in the range of 15 to 35 parts by mass with respect to 100 parts by mass of the silica particles.

The surface modification treatment of the silica particles is preferably performed at a temperature in the range of 60 ° C. to 90 ° C. for 0.5 to 2 hours.

[Creation of silicone resin sheet]
The silicone resin sheet is prepared, for example, by a method including a step of kneading the above-described organopolysiloxane and silica particles and a step of curing the kneaded product by heating. An example of a method for producing a silicone resin sheet is described in JP 2013-227474 A. The silicone resin composition may further contain additives such as a curing catalyst, a pigment, a dye, a dispersant, an antioxidant, a flame retardant, and an antistatic agent in addition to the above-described substances.

A known catalyst can be used as the curing catalyst, and for example, an alkyl peroxide or an acyl peroxide can be used. The curing catalyst is preferably selected as appropriate according to the molding method. Specifically, when producing a silicone resin sheet by press molding, it is preferable to use an alkyl peroxide. Moreover, when producing a silicone resin sheet by extrusion molding, it is preferable to use an acyl peroxide.

By using an alkyl peroxide as a curing catalyst, by-products can be reduced compared to the case of using an acyl peroxide. Since the silicone resin sheet containing such a curing catalyst is a sheet having no skin sensitization and biotoxicity and high biocompatibility, it is preferable as a member of the bag-like structure 22 included in the cuff 20.

As the alkyl peroxide, for example, cumyl-t-butyl peroxide, dicumyl peroxide or benzoyl peroxide can be used.

The amount of the alkyl peroxide is preferably in the range of 0.05 to 10 parts by mass, preferably in the range of 0.5 to 3 parts by mass with respect to 100 parts by mass in total of the organopolysiloxane and the silica particles. More preferably.

Kneading can be performed using a known kneading apparatus. As a kneading apparatus, for example, a two roll and a kneader can be used.

The kneaded material obtained by kneading is poured into, for example, a press mold and is primarily cured by heating. Primary curing occurs, for example, by heating at a temperature of 140 ° C. to 180 ° C. for 6 to 10 minutes.

Next, secondary curing is performed by further raising the heating temperature. Secondary curing is performed by heating at 200 ° C. for 4 hours, for example.

The silicone resin sheet obtained in this way has a low crosslink density and a Shore A hardness within the above range. That is, the silicone resin sheet thus obtained is a relatively flexible sheet. Therefore, by using such a silicone resin sheet for the bag-like structure 22, it is possible to realize excellent compression characteristics with respect to the biological surface.

Further, in the silicone resin sheet obtained in this way, in addition to the organopolysiloxane being crosslinked, the silica particles and the organopolysiloxane are bonded. Therefore, this silicone resin sheet is less likely to break the material itself when high tension is applied, and it is difficult to cause creep deformation even when tension is repeatedly applied.

The bag-like structure 22 is prepared by, for example, sizing a silicone resin sheet prepared by the above-described method into a plurality of sheet members having a predetermined shape and bonding the sheet members with molecular bonding or double-sided tape.

<Measurement of blood pressure>
Next, measurement of blood pressure values using the sphygmomanometer 1 will be described with reference to FIGS.

FIG. 4 is a cross-sectional view schematically showing a state in which a cuff included in the blood pressure monitor shown in FIG. 1 is attached to a living body. FIG. 5 is a cross-sectional view showing the same state as FIG. 4 except that the bag-like structure included in the cuff is expanded. In the following description, it is assumed that the subject himself performs all operations.

When measuring the blood pressure value, the subject wears the cuff 20 on the living body. Here, the subject wears the cuff 20 on the wrist 30 as shown in FIG. Next, the subject operates the operation unit 113 shown in FIG. 1 to input a command corresponding to the start of blood pressure measurement.

When this command is input, the operation unit 113 outputs an electrical signal corresponding to the start of measurement to the control unit 118. The control unit 118 to which this signal is supplied controls their operations so that the valve 115 is closed and the pump 114 starts driving. Thereby, the bag-like structure 22 starts to expand.

The pressure sensor 116 detects the pressure in the internal space of the bag-like structure 22 and outputs an electrical signal corresponding to this pressure to the control unit 118. Based on this electrical signal, the control unit 118 determines whether or not the pressure in the internal space of the bag-like structure 22 has reached a predetermined level for blood pressure measurement. Then, the control unit 118 controls the operation so that the pump 114 stops driving when the pressure reaches the previous level. Immediately after the pump 114 stops driving, as shown in FIG. 5, the bag-like structure 22 is sufficiently inflated, and the cuff 20 closes the artery 31 at the position of the wrist 30.

Thereafter, the control unit 118 controls the operation so that the valve 115 is gradually opened. When the valve 115 is opened, the air inside the bag-like structure 22 is exhausted, and the pressure in the internal space decreases. During this decompression process, the flow of blood 32 in the artery 31 resumes. The control unit 118 obtains measurement results such as blood pressure values such as systolic blood pressure and diastolic blood pressure and heart rate from the electrical signal output from the pressure sensor 116 in this process, and displays image signals corresponding to the measurement results as shown in FIG. To the display unit 112 shown in FIG.

When the display unit 112 receives the previous image signal, the display unit 112 displays the measurement result on the screen. The subject checks the measurement result by visually recognizing the display unit 112. In addition, a test subject removes a fastener and removes the blood pressure meter 1 from the wrist 30 after completion | finish of a measurement.

<Effect>
The bag-like structure 22 included in the sphygmomanometer 1 is excellent in flexibility and has high creep resistance. Therefore, the sphygmomanometer 1 is excellent in durability and can measure the blood pressure value with high accuracy. This will be described below.

¡If the cuff is narrowed, the vascular compression area decreases, and the blood pressure value may not be measured with high accuracy. When the bag-like structure is made of a flexible material, the followability to the living body shape is enhanced, and the blood pressure value can be measured with high accuracy even when the cuff is narrowed.

However, when the bag-like structure is constituted by such a flexible material, for example, a material having a Shore A hardness in the range of 10 to 75, as shown in FIG. Along with this, it has been found that the amount of creep deformation increases.

FIG. 6 is a graph showing an example of creep deformation accompanying repeated use. The data shown in FIG. 6 shows that a test piece is cut out from a flexible silicone resin sheet, both ends of the test piece are gripped and a tensile load is repeatedly applied, and the tensile load (load) and the tensile load are never applied. It was obtained by recording the elongation (displacement amount) of the test piece based on the initial length. In the graph of FIG. 6, the vertical axis represents the load (N) and the horizontal axis represents the displacement (mm). The solid line is the data obtained when the tensile load is applied for the first time, the alternate long and short dash line is the data obtained when the number of times the tensile load is applied is the 1000th time, and the broken line is the data obtained when the tensile load is applied. This is the data obtained when the number of times is 30000th.

As shown in FIG. 6, the silicone resin sheet normally undergoes creep deformation when tension is repeatedly applied. Therefore, when a bag-like structure is constituted by such a silicone resin sheet, the amount of creep deformation of the silicone resin sheet increases as the use of the bag-like structure is repeated. If the silicone resin sheet undergoes a large creep deformation, the vascular compression area or the like changes, which may make it difficult to measure blood pressure with high accuracy.

In addition, the expansion pressure tends to concentrate at the adhesion site between the sheets. Therefore, there is a possibility that the bonded portion is broken as shown in FIG.

FIG. 7 is a perspective view schematically showing an example of breakage that can occur in the bonded portion of the bag-like structure due to creep deformation. The sheet member 40a and the sheet member 40b shown in FIG. 7 are joined at the position of the joining region 41 to constitute a bag-like structure. FIG. 7 illustrates a joint portion destroyed by repeatedly expanding and contracting the bag-like structure, specifically, the separation of the sheet member 40a and the sheet member 40b generated at the position of the joint region 41. Yes.

When the destruction as shown in FIG. 7 occurs, the bag-like structure leaks air, and normal blood pressure measurement becomes difficult.

As a result of intensive studies on this, the present inventors have used a silicone resin sheet having a Shore A hardness and a tensile elongation at break in the above-mentioned ranges for the bag-like structure, thereby providing excellent flexibility and high creep resistance. It has been found that both of these can be achieved.

The inventors of the present invention have the following reasons why both excellent flexibility and high creep resistance can be achieved when a silicone resin sheet having a Shore A hardness and a tensile elongation at break within the above ranges is used. I think there is.

FIG. 8 is an enlarged view schematically showing the structure of the sheet forming the bag-like structure according to one embodiment of the present invention. FIG. 9 is an enlarged view schematically showing the structure of the sheet according to the comparative example.

In the silicone resin sheet having the Shore A hardness and the tensile elongation at break within the above ranges, as shown in FIG. 8, the organopolysiloxane 50 forms a crosslinked structure with a low crosslinking density. This small crosslink density contributes to the flexibility of the sheet.

Further, in this silicone resin sheet, silica particles 51 are incorporated in the crosslinked structure of the organopolysiloxane 50. That is, the organopolysiloxane 50 and the silica particles 51 are bonded. This bonding suppresses a relative positional shift between the crosslinked structure formed by the organopolysiloxane 50 and the silica particles 51 due to repeated application and release of tension to the silicone resin sheet. In addition, since a plurality of organopolysiloxanes 50 are usually bonded to each silica particle 51, the above bonding is accompanied by repeated application of tension to the silicone resin sheet and release thereof. The relative position shift of the molecule is also suppressed. That is, the above bonding suppresses creep deformation of the silicone resin sheet.

Here, the above-described bonding not only suppresses the above-described deviation, but also contributes to an improvement in the tensile breaking strength of the sheet. That is, in this silicone resin sheet, its creep resistance and tensile elongation at break are correlated.

Therefore, a silicone resin sheet having a Shore A hardness and a tensile elongation at break within the above ranges has high creep resistance despite being flexible.

On the other hand, in the silicone resin sheet according to the comparative example in which the Shore A hardness is in the above range, but the tensile elongation at break is below the lower limit, as shown in FIG. Not combined with. Therefore, when the application of the tension to the sheet and the release thereof are repeated, the relative position between the crosslinked structure formed by the organopolysiloxane 50 and the silica particles 51 is shifted, and the molecules of the organopolysiloxane 50 are displaced. The relative position is also displaced. Therefore, even if such a silicone resin sheet is flexible, it cannot have high creep characteristics.

The influence of the bond between the organopolysiloxane 50 and the silica particles 51 described above on the tensile elongation at break of the silicone resin sheet will be described with reference to FIG.

FIG. 10 is a stress strain diagram of a sheet that can be used for a bag-like structure according to an embodiment of the present invention and a sheet that can be used for a bag-like structure according to a comparative example. The data shown in FIG. 10 is obtained in the process of measuring the tensile elongation at break described above for test pieces cut out from the silicone resin sheets A to E described below.

Sheet A and D have a Shore A hardness of 30, Sheet B has a Shore A hardness of 40, and Sheets C and E have a Shore A hardness of 70. Sheets A, B, and C are sheets that have a bond between the above-described organopolysiloxane 50 and silica particles 51, and sheets D and E are sheets that do not have the bond.

As shown in FIG. 10, the elongation (tensile breaking elongation) of the sheet D having a Shore A hardness of 30 is 350%, and the tensile breaking elongation of the sheet E having a Shore A hardness of 70 is 700%. That is, when the organopolysiloxane 50 is not bonded to the silica particles 51, increasing the Shore A hardness increases the tensile elongation at break. That is, a silicone resin sheet in which the organopolysiloxane 50 is not bonded to the silica particles 51 cannot simultaneously achieve a small Shore A hardness and a large tensile elongation at break.

On the other hand, the sheets A to C achieve a tensile breaking elongation of 1000% or more. As can be seen from the results of the sheets A to C, when the organopolysiloxane 50 is bonded to the silica particles 51, when the Shore A hardness is reduced, the tensile elongation at break increases. That is, in the silicone resin sheet in which the organopolysiloxane 50 is bonded to the silica particles 51, it is possible to simultaneously achieve a small Shore A hardness and a large tensile elongation at break.

Thus, the bond between the organopolysiloxane 50 and the silica particles is important for achieving a small Shore A hardness and a large tensile elongation at break.

The above-described bag-like structure 22 uses a silicone resin sheet having a Shore A hardness and a tensile elongation at break within the above ranges, and therefore has a high physical property margin until creep rupture. Therefore, this bag-like structure 22 has a low risk of creep destruction due to repeated expansion and contraction.

The bag-like structure 22 includes a silicone resin sheet having high creep resistance despite being flexible. Therefore, the sphygmomanometer 1 using the bag-like structure 22 for the cuff 20 has high durability and can measure the blood pressure value with high accuracy. And, even when the cuff is ultra-narrow like a wearable sphygmomanometer, for example, when the cuff width is about 25 mm, excellent durability and blood pressure measurement characteristics similar to those of the upper arm type sphygmomanometer are achieved. Is possible.

<Modification of bag-like structure>
Various modifications can be made to the bag-like structure 22 described above. Here, a modification will be described with reference to FIGS. The bag-like structure according to this modification can be used for the cuff 20 of the sphygmomanometer 1 described above, for example.

FIG. 11 is a cross-sectional view schematically showing a modification of the bag-like structure shown in FIGS. FIG. 12 is a cutaway perspective view of a bag-like structure according to a modification.

As shown in FIGS. 11 and 12, the bag-like structure 22 according to the modification includes an inner wall part 221, an outer wall part 222, a side wall part 223, a connecting part 226, and a connection tube 228.

The inner wall part 221 and the outer wall part 222 are rectangular and face each other.
The side wall part 223 is provided between the pair of ends along the length direction of the inner wall part 221 and the outer wall part 222 so as to be continuous with the inner wall part 221 and the outer wall part 222. These side wall portions 223 together with the inner wall portion 221 and the outer wall portion 222 define an internal space of the bag-like structure 22. The side wall part 223 is a deformation of the bag-like structure 22 in a direction in which the inner wall part 221 and the outer wall part 222 are separated from each other when the pressure in the internal space of the bag-like structure 22 is increased, that is, the bag-like structure 22 Promotes deformation in the thickness direction.

Each of the side wall portions 223 has a shape extending in the length direction of the bag-like structure 22, and one end extending along the length direction extends along the length direction of the inner wall portion 221. The other end that is joined to one end and extends along the length direction is joined to the other end that extends along the length direction of the outer wall portion 222.

Here, each side wall portion 223 is a composite formed by superposing two sheet members, specifically, a sheet member 224 and a sheet member 225, and joining them at one end extending in the length direction. It is. That is, the sheet member 224 and the sheet member 225 are joined at an end that is not joined to the inner wall portion 221 or the outer wall portion 222 among the ends along the length direction thereof. Specifically, the other end of the sheet member 224 is continuous with the end along the length direction of the inner wall portion 221. The other end of the sheet member 225 is continuous with the end along the length direction of the outer wall portion 222. Each side wall portion 223 may have a structure in which one sheet member is bent.

Such a bag-like structure 22 is sometimes called a Σ structure or a bellows structure because of its shape. This structure further promotes deformation in the thickness direction when the bag-like structure 22 is inflated.

The connecting portion 226 is located between the inner wall portion 221 and the outer wall portion 222 and connects the pair of side wall portions 223 in a direction orthogonal to the longitudinal direction of the bag-like structure 22. Here, the connecting portion 226 is provided on a surface that is not bonded to the sheet member 225 at an end continuous with the sheet member 225 among the ends along the length direction of the sheet member 224.

The connecting portion 226 includes an inner space A in which the inner space of the bag-like structure 22 is surrounded by the inner wall portion 221, the connecting portion 226, and the pair of side wall portions 223, and the outer wall portion 222, the connecting portion 226, and the pair of side wall portions. And an internal space B surrounded by 223. The connection portion 226 is provided with one or more communication holes 227 that fluidly communicate the internal space A and the internal space B. The connecting portion 226 suppresses deformation in the width direction when the bag-like structure 22 is inflated. For example, the connecting portion 226 may be integrated with the sheet member 224 or 225.

Such a bag-like structure 22 has a connecting portion 226 that connects the pair of side wall portions 223 in the internal space of the bag-like structure 22, thereby maintaining the shape of the side wall portion 223 being folded. can do. Moreover, since the side wall part 223 is connected by the connection part 226, expansion | swelling to the outer side of those side wall parts is restrict | limited at the time of expansion | swelling, and the bag-like structure 22 promotes expansion | swelling to the thickness direction of a cuff. can do. Therefore, the use of the bag-like structure 22 having such a structure is most effective in achieving both long-term durability and excellent blood pressure measurement characteristics particularly in the ultra-narrow cuff. The connecting portion 226 may be omitted.

Of the sheets constituting the bag-like structure 22, it is preferable to use a sheet satisfying the above-described conditions for at least the inner wall portion 221. The bag-like structure 22 having such a structure is advantageous in reducing the risk of creep destruction due to creep deformation due to repeated use of the sphygmomanometer 1 including the structure. This is because, in the sheet member constituting the bag-like structure 22, the region located on the living body side is likely to be scratched and easily affected by creep deformation.

Among the sheets constituting the bag-like structure 22, it is preferable to use a sheet that satisfies the above-described conditions for at least the side wall portion 223. When the bag-like structure 22 having such a structure is inflated, the expansion of the bag-like structure 22 in the thickness direction can be further promoted. Moreover, since the largest tension is applied to the side wall part 223 when the sphygmomanometer 1 is used, creep deformation is likely to occur. Therefore, such a bag-like structure 22 exhibits high creep resistance.

Of the sheets constituting the bag-like structure 22, it is preferable to use a sheet that satisfies the above-described conditions for at least a bonding portion between the sheet members and a portion adjacent thereto. When the bag-like structure 22 having such a structure is subjected to repeated expansion and contraction, it is difficult for creep fracture to occur in the bonded portion due to creep deformation.

In addition, among the sheets constituting the bag-like structure 22, at least the inner wall part 221, the side wall part 223, and the sheet adhering part and the part adjacent thereto should use sheets satisfying the above-described conditions. It is preferable to use a sheet satisfying the above-described conditions for all the sheets constituting the bag-like structure 22. The bag-like structure 22 having such a structure is advantageous in achieving particularly excellent performance in terms of both flexibility and creep resistance.

The bag-like structure 22 is configured, for example, by sizing a silicone resin sheet into a plurality of sheet members having a predetermined shape and joining the sized sheet members. In addition, as long as the above-described conditions are satisfied, sheet members having different Shore A hardness and / or sheet thickness may be combined.

In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not deviate from the summary. Further, the embodiments may be implemented in combination as appropriate, and in that case, the combined effect can be obtained. Furthermore, the present invention includes various inventions, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, even if several constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the problem can be solved and an effect can be obtained, the configuration from which the constituent requirements are deleted can be extracted as an invention.

Specific examples of the present invention will be described below. However, the scope of the present invention is not limited to the following examples.

(Example 1)
The bag-like structure 22 described with reference to FIGS. 2 and 3 was manufactured. In this example, the same silicone resin sheet was used for the material of the inner wall part 221 and the outer wall part 222. As this silicone resin sheet, a silicone resin sheet having a Shore A hardness of 30 and a tensile breaking elongation of 2400% was used. Moreover, the thickness of the inner wall part 221 and the outer wall part 222 was 0.15 mm. The silicone resin sheet having the above properties was cut into a sheet member having a width of 27 mm and a length of 100 mm, and these were used as an inner wall portion 221 and an outer wall portion 222. Next, these sheet members were superposed and their ends were joined using a molecular adhesive. The adhesion width was 1.0 mm.

(Example 2)
A bag-like structure 22 was produced in the same manner as in Example 1 except that a silicone resin sheet having a Shore A hardness of 70 and a tensile elongation at break of 1000% was used as the silicone resin sheet.

(Example 3)
Silicone resin sheet Shore A A bag-like structure 22 was produced in the same manner as in Example 1 except that a silicone resin sheet having a hardness of 15 and a tensile breaking elongation of 3600% was used.

(Example 4)
Silicone resin sheet Shore A A bag-like structure 22 was produced in the same manner as in Example 1 except that a silicone resin sheet having a hardness of 10 and a tensile elongation at break of 4000% was used.

(Example 5)
Silicone resin sheet Shore A A bag-like structure 22 was produced in the same manner as in Example 1 except that a silicone resin sheet having a hardness of 75 and a tensile elongation at break of 1000% was used.

(Comparative Example 1)
Silicone resin sheet Shore A A bag-like structure was produced in the same manner as in Example 1 except that a silicone resin sheet having a hardness of 30 and a tensile elongation at break of 350% was used.

(Comparative Example 2)
Silicone resin sheet Shore A A bag-like structure was produced in the same manner as in Example 1 except that a silicone resin sheet having a hardness of 70 and a tensile breaking elongation of 750% was used.

(Comparative Example 3)
Silicone resin sheet Shore A A bag-like structure was produced in the same manner as in Example 1 except that a silicone resin sheet having a hardness of 10 and a tensile elongation at break of 250% was used.

(Comparative Example 4)
A bag-like structure was produced in the same manner as in Example 1 except that a silicone resin sheet having a Shore A hardness of 75 and a tensile elongation at break of 650% was used.

<Evaluation of creep resistance>
The bag-like structure of Example 1 was evaluated for creep resistance. Specifically, ten bag-like structures 22 of Example 1 were prepared, and each of them was expanded and contracted. The pressure of the compressed air was 450 mmHg (= 450 × 101325/760 Pa). This expansion and contraction was repeated 30,000 times, and the presence or absence of air leakage caused by destruction of the joint portion of the bag-like structure or the presence or absence of air leakage caused by cracking of the bag-like structure was evaluated. The bag-like structure in which no air leakage was confirmed was evaluated as “◯”. And the number of the bag-like structures in which air leakage was not confirmed was investigated. The same evaluation was performed for the bag-like structures of Examples 2 to 5 and Comparative Examples 1 to 4.

<Result>
The results of the evaluation test are shown in Table 1.

As shown in Table 1, the bag-like structures of Examples 1 to 5 had good creep resistance. In particular, in Examples 1 to 3, no leakage was observed in all of the 10 bag-like structures, and excellent creep resistance was exhibited. In Examples 4 and 5, unlike Examples 1 to 3, although leakage was observed in some of the bag-like structures, no leakage was observed in about half of the bag-like structures. On the other hand, in Comparative Examples 1 to 4, air leakage was observed in all 10 bag-like structures.

Claims (5)

An inner wall portion and an outer wall portion facing the inner wall portion, and at least one of the inner wall portion and the outer wall portion has a Shore A hardness in the range of 10 to 75 and a tensile elongation at break of 1000% or more. A bag-like structure including a sheet made of a certain silicone resin. The bag-like structure according to claim 1, wherein the thickness of the sheet is in the range of 0.10 mm to 0.60 mm. The bag-like structure according to claim 1 or 2, wherein the silicone resin has a Shore A hardness of 15 to 70. A cuff containing the bag-like structure according to any one of claims 1 to 3 so that at least a part of the sheet is located on the living body side when the bag is attached to the living body. A sphygmomanometer comprising the cuff according to claim 4.

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