One or more embodiments of the present invention relate to a fluid bladder, and more specifically relates to a fluid bladder that is provided in a blood pressure measurement cuff and is for compressing a measurement site.
Also, one or more embodiments of the present invention relate to a blood pressure measurement cuff, and more specifically relates to a blood pressure measurement cuff that is wrapped around and compresses a measurement site such as an upper arm or a wrist.
Also, one or more embodiments of the present invention relate to a blood pressure monitor including this kind of blood pressure measurement cuff.
Also, one or more embodiments of the present invention relate to a blood pressure measurement method for measuring blood pressure using a cuff.
Conventionally, as disclosed in Patent Document 1 (JP 2003-24286) for example, a blood pressure measurement cuff has been known which includes a first air bladder and a second air bladder composed of a material with higher elasticity than the first air bladder, which are overlaid between a band for wrapping around a wrist serving as a measurement site and a half surface on the palm side (the ulnar artery and radial artery side) of the wrist. With this cuff, the arteries are compressed by inflating the first air bladder as well as the second air bladder.
Patent Document 1: JP 2003-24286A
According to analysis performed by the inventor, as shown in
In view of this, one or more embodiments of the present invention aim to provide a fluid bladder that is provided in a blood pressure measurement cuff, can bring the measured values for blood pressure closer to the true values, and can increase measurement accuracy.
Also, one or more embodiments of the present invention aim to provide a blood pressure measurement cuff that can bring the measured values for blood pressure closer to the true values and can increase measurement accuracy.
Also, one or more embodiments of the present invention aim to provide a blood pressure monitor including this kind of blood pressure measurement cuff.
Also, one or more embodiments of the present invention aim to provide a blood pressure measurement method according to which it is possible to bring the measured values for blood pressure closer to the true values and to increase measurement accuracy.
A fluid bladder according to one or more embodiments of the present invention is
a fluid bladder that is to be provided on a band-shaped blood pressure measurement cuff to be attached by being wrapped around a substantially rod-shaped measurement site, and is for compressing the measurement site, including:
a first fluid bladder region that that swells due to receiving a supply of fluid from an outside supply source and is arranged at a portion of an outer circumferential surface of the measurement site that corresponds to a first half surface where an artery is, in a lengthwise direction of the cuff; and
a second fluid bladder region that swells due to receiving a supply of fluid from the outside supply source and is arranged at a portion of the outer circumferential surface of the measurement site that corresponds to a second half surface opposite to the first half surface, in the lengthwise direction of the cuff,
wherein a configuration is used in which during inflation for blood pressure measurement, the first fluid bladder region and the second fluid bladder region are inflated to the same pressure and a stroke amount by which the second fluid bladder region swells is larger in a thickness direction of the cuff than a stroke amount by which the first fluid bladder region swells.
In the present specification, the “lengthwise direction” of the cuff refers to the direction corresponding to the direction of wrapping the outer circumferential surface of the measurement site. Also, the “thickness direction” of the cuff refers to a direction corresponding to the direction orthogonal to the outer circumferential surface of the measurement site.
Also, “outside” means the outside with respect to the cuff.
Also, “stroke amount” means a distance of swelling or expansion in the thickness direction.
When the blood pressure measurement cuff including the fluid bladder according to one or more embodiments of the present invention is attached by being wrapped around the measurement site, the first fluid bladder region corresponds to the first half surface, which is where the arteries exist, of the outer circumferential surface of the measurement site, and the second fluid bladder region corresponds to the second half surface, which is opposite to the first half surface, of the outer circumferential surface of the measurement site. During inflation for blood pressure measurement, the first fluid bladder region swells due to receiving a supply of fluid from an outside supply source. The second fluid bladder region also swells due to receiving a supply of fluid from the supply source. Here, with the fluid bladder, a configuration is used in which the first fluid bladder region and the second fluid bladder region are inflated to the same pressure and the stroke amount by which the second fluid bladder region expands is larger in the thickness direction of the cuff than the stroke amount by which the first fluid bladder region swells. Accordingly, when the first fluid bladder region and the second fluid bladder region are inflated to a certain pressure (the same pressure), the stroke amount by which the second fluid bladder region swells is larger in the thickness direction than the stroke amount by which the first fluid bladder region swells. Conversely, the first fluid bladder region swells less compared to the case where the second fluid bladder region does not exist and the case where the stroke amount by which the second fluid bladder region swells is less than or equal to the stroke amount by which the first fluid bladder region swells. Accordingly, the distance by which the arteries that exist at the measurement site withdraw due to being pressed by the first fluid bladder region decreases and the extra inflation amount for pressing the arteries decreases. As a result, the measured values for the blood pressure measured by inflating the fluid bladder can be brought closer to the true values, and the measurement accuracy can be increased. Also, during inflation for blood pressure measurement, in order to control the cuff pressure, it is sufficient that the control unit mounted in the blood pressure monitor main body, for example, controls the supply source so as to perform supply of the fluid to the first and second fluid bladder regions and discharge of the fluid from the first and second fluid bladder regions. Accordingly, control of the cuff pressure is simplified compared to the case where an element that expands or swells due to a different type of action than the fluid bladder, such as an actuator, for example, is included as the expansion region corresponding to the second half surface instead of the second fluid bladder region.
With a fluid bladder of an embodiment, the first fluid bladder region and the second fluid bladder region are in communication.
With the fluid bladder of this embodiment, since the first fluid bladder region and the second fluid bladder region are in communication, the first fluid bladder region and the second fluid bladder region can be inflated to the same pressure during inflation for blood pressure measurement.
With a fluid bladder of an embodiment,
the first fluid bladder region is a portion of a parent bladder that extends in the lengthwise direction, the portion corresponding to the first half surface, and
the second fluid bladder region is formed by overlaying a child bladder in a thickness direction on a portion of the parent bladder corresponding to the second half surface, and the fluid can flow between the parent bladder and the child bladder.
Here, “parent bladder” and “child bladder” are terms used for the sake of convenience to distinguish between the two bladders.
With the fluid bladder of this embodiment, during inflation for blood pressure measurement, when the first fluid bladder region and the second fluid bladder region are inflated to a certain pressure (the same pressure), the first fluid bladder region swells by a certain stroke amount in the thickness direction. At this time, the stroke amount of the first fluid bladder region is suppressed to a level corresponding to the parent bladder (one bladder). On the other hand, in the second fluid bladder region, the child bladder is overlaid on the parent bladder in the thickness direction. Accordingly, when the second fluid bladder region swells in the thickness direction, the stroke amount of the second fluid bladder region increases to a level corresponding to the parent bladder and the child bladder (at least two bladders). As a result, the stroke amount of the second fluid bladder region is larger than the stroke amount of the first fluid bladder region in the thickness direction. With the fluid bladder of this embodiment, the second fluid bladder region can be configured easily and inexpensively.
With a fluid bladder of an embodiment, a dimension in a width direction of the second fluid bladder region is set to be larger than a dimension in a width direction of the first fluid bladder region.
Here, “width direction” refers to a direction orthogonal to the lengthwise direction and the thickness direction. In the state in which the blood pressure measurement cuff including the fluid bladder is attached to the measurement site, the width direction corresponds to the direction along the arteries passing through the measurement site.
With the fluid bladder of this embodiment, during inflation for blood pressure measurement, the first fluid bladder region and the second fluid bladder region are inflated to the same pressure and swell. Here, the cross sections of the fluid bladder regions approach a circular shape as they swell, and if the width direction dimension of the fluid bladder region is large, the stroke amount in the thickness direction of the fluid bladder region increases accordingly. Accordingly, the second fluid bladder region swells by the stroke amount, which is larger in the thickness direction than the stroke amount of the first fluid bladder region. With the fluid bladder of this embodiment, the second fluid bladder region serving as the expansion region can be configured easily and inexpensively.
With a fluid bladder of an embodiment, in the second fluid bladder region, a pair of sheets that form the second fluid bladder region face each other in the thickness direction and edge portions in the width direction of the pair of sheets are welded or adhered in a state of being overlaid facing mutually opposite directions.
With the fluid bladder of this embodiment, during inflation for blood pressure measurement, when the first fluid bladder region and the second fluid bladder region are inflated to a certain pressure (the same pressure), the first fluid bladder region swells by a certain stroke amount in the thickness direction. Here, in the second fluid bladder region, a pair of sheets that form the second fluid bladder region face each other in the thickness direction and edge portions in the width direction of the pair of sheets are welded or adhered in a state of being overlaid facing mutually opposite directions. Accordingly, when the second fluid bladder region swells in the thickness direction, unlike the case where the edge portions of the pair of sheets are overlaid facing outward, there is no need to bend in order to open and no restriction occurs due to the inflexibility (stiffness) of the sheet material. As a result, the stroke amount in the thickness direction of the second fluid bladder region further increases. Accordingly, the measurement accuracy can be further increased. With the fluid bladder of this embodiment, the second fluid bladder region can be configured easily and inexpensively.
With a fluid bladder of an embodiment, a side portion of the second fluid bladder region is bellows-shaped or folded in a zig-zag shape in a cross-sectional view along the lengthwise direction in its natural state.
With the fluid bladder of this embodiment, during inflation for blood pressure measurement, when the first fluid bladder region and the second fluid bladder region are inflated to a certain pressure (the same pressure), the first fluid bladder region swells by a certain stroke amount in the thickness direction. At this time, the stroke amount of the first fluid bladder region is suppressed according to the amount by which the side portion stretches. On the other hand, a side portion of the second fluid bladder region is bellows-shaped or folded in a zig-zag shape in a cross-sectional view along the lengthwise direction in its natural state. Accordingly, when the second fluid bladder region swells in the thickness direction, the side portion that is bellows-shaped in its natural state or is folded in a zig-zag shape stretches. As a result, the stroke amount in the thickness direction of the second fluid bladder region further increases. Accordingly, the measurement accuracy can be further increased. With the fluid bladder of this embodiment, the second fluid bladder region can be configured easily and inexpensively.
With a fluid bladder of an embodiment, a thickness of the side portion of the second fluid bladder is thinner than a thickness of a sheet portion on a side away from the measurement site that forms the second fluid bladder region.
With the fluid bladder of this embodiment, during inflation for blood pressure measurement, when the first fluid bladder region and the second fluid bladder region are inflated to a certain pressure (the same pressure), the first fluid bladder region swells by a certain stroke amount in the thickness direction. Here, a thickness of the side portion of the second fluid bladder is thinner than a thickness of a sheet portion on a side away from the measurement site that forms the second fluid bladder region. Accordingly, when the second fluid bladder region swells in the thickness direction, the side portion of the second fluid bladder region is easier to stretch. As a result, the stroke amount in the thickness direction of the second fluid bladder region further increases. With the fluid bladder of this embodiment, the second fluid bladder region can be configured easily and inexpensively.
With a fluid bladder of an embodiment, a hardness of the side portion of the second fluid bladder is smaller than a hardness of a sheet portion on a side away from the measurement site that forms the second fluid bladder region.
With the fluid bladder of this embodiment, during inflation for blood pressure measurement, when the first fluid bladder region and the second fluid bladder region are inflated to a certain pressure (the same pressure), the first fluid bladder region swells by a certain stroke amount in the thickness direction. Here, a hardness of the side portion of the second fluid bladder is smaller than a hardness of a sheet portion on a side away from the measurement site that forms the second fluid bladder region. Accordingly, when the second fluid bladder region swells in the thickness direction, the side portion of the second fluid bladder region is easier to stretch. As a result, the stroke amount in the thickness direction of the second fluid bladder region further increases. With the fluid bladder of this embodiment, the second fluid bladder region can be configured easily and inexpensively.
According to another aspect, a blood pressure measurement cuff according to one or more embodiments of the present invention is a band-shaped blood pressure measurement cuff that is attached by being wrapped around a substantially rod-shaped measurement site, and includes the above-described fluid bladder.
With the blood pressure measurement cuff according to one or more embodiments of the present invention, because of the fluid bladder, the measured values for the blood pressure can be brought closer to the true values, and the measurement accuracy can be increased.
According to another aspect, a blood pressure monitor according to one or more embodiments of the present invention is a blood pressure monitor that includes the above-described blood pressure measurement cuff and a main body that includes an element for blood pressure measurement.
With the blood pressure monitor according to one or more embodiments of the present invention, because of the cuff, it is possible to bring the measured values for blood pressure closer to the true values and to increase measurement accuracy.
Furthermore, in another aspect, a blood pressure measurement method according to one or more embodiments of the present invention is
a blood pressure measurement method including attaching a band-shaped measurement cuff such that it wraps around a substantially rod-shaped measurement site, wherein
the cuff includes:
a first fluid bladder that swells due to receiving a supply of fluid and is arranged at a portion of an outer circumferential surface of the measurement site that corresponds to a first half surface where an artery is, in a lengthwise direction of the cuff, and
a second fluid bladder that swells due to receiving a supply of fluid and is arranged at a portion of the outer circumferential surface of the measurement site that corresponds to a second half surface opposite to the first half surface, in a lengthwise direction of the cuff,
during inflation for blood pressure measurement, the pressure of the second fluid bladder is made larger than the pressure of the first fluid bladder by supplying more fluid to the second fluid bladder than to the first fluid bladder such that the stroke amount by which the second fluid bladder swells is larger in the thickness direction of the cuff than the stroke amount by which the first fluid bladder swells, and
after the stroke amount by which the second fluid bladder swells is made larger in the thickness direction than the stroke amount by which the first fluid bladder swells, the first fluid bladder and the second fluid bladder are inflated at pressure increase rates that are substantially equal to each other, and in the process of inflating, or in the process of deflating at pressure reduction rates that are equal to each other after the process of inflating, blood pressure measurement is performed.
With the blood pressure measurement method according to one or more embodiments of the present invention, the cuff is attached by being wrapped around the measurement site, and during inflation for blood pressure measurement, the pressure of the second fluid bladder is made larger by supplying a larger amount of fluid to the second fluid bladder than to the first fluid bladder such that the stroke amount by which the second fluid bladder swells is larger in the thickness direction of the cuff than the stroke amount by which the first fluid bladder swells. Thereafter, the first fluid bladder and the second fluid bladder are inflated at pressure increase rates that are substantially equal to each other, and in the process of inflating, or in the process of deflating at pressure reduction rates that are equal to each other after the process of inflating, blood pressure measurement is performed. Accordingly, the amount by which the arteries at the measurement site move due to being pushed by the first fluid bladder decreases, and the extra inflation amount of the first fluid bladder for pressing the arteries decreases. As a result, the measured values for blood pressure measured through inflation using the first fluid bladder can be brought closer to the true values and measurement accuracy can be increased.
As is evident from the above description, according to the fluid bladder, the blood pressure measurement cuff, the blood pressure monitor, and the blood pressure measurement method, the measured values for blood pressure can be brought closer to the true values and the measurement accuracy can be increased.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First Embodiment
As can be understood from
Along the lengthwise direction Y (corresponds to the circumferential direction in
A ring 80 that has a substantially oval shape is attached to the outer circumferential surface of the first portion 20E. The lengthwise direction of the ring 80 intersects with the lengthwise direction of the cuff 20. The dimension in the lengthwise direction of the ring 80 is set to be slightly larger than the width direction dimension W of the cuff 20 such that the cuff 20 (in particular, the third portion 20F) can easily pass therethrough. The reason why the ring 80 intersects with an inclination from the upper left to the lower right in
A planar fastener 70 is attached to the surface of the portion of the third portion 20F of the cuff 20 that is nearest to the main body 10. In this example, the planar fastener 70 includes many minute hooks (not shown) on its surface. The outer circumferential surface of the third portion 20F excluding the nearest portion (planar fastener 70) has many minute loops (not shown) that engage with the hooks.
An air bladder 22 serving as a fluid bladder for compressing the wrist 90 is contained in the cuff 20 spanning from the first portion 20E to the third portion 20F.
The air bladder 22 includes a parent bladder 23 that is arranged on the side (corresponds to the inner circumferential side shown in
Here, the portion (included in the third portion 20F) corresponding to the half surface (first half surface of the outer circumferential surface of the wrist 90, where the ulnar artery and the radial artery exist) 90a on the palm side of the air bladder 22 that extends in the lengthwise direction Y will be referred to as “first fluid bladder region A1”. On the other hand, the portion (approximately corresponds to the second portion 20C) of the air bladder 22 in which the child bladder 24 is arranged, and which corresponds to the half surface (second half surface opposite to the half surface 90a on the palm side 90a of the outer circumferential surface of the wrist 90) 90b on the back side will be referred to as “second fluid bladder region A2”.
In the case of producing the air bladder 22, two approximately flat sheets 41 and 42 for forming the parent bladder 23 and two approximately flat sheets 43 and 44 for forming the child bladder 24 are prepared, as shown in
The air bladder 22 is contained in the cuff 20 in a state in which the nipple 45 attached to the sheet 41 protrudes through the outer cloth 20A. When the main body 10 and the cuff 20 are joined, an air tube 10A of the main body 10 is fit air-tightly into the nipple 45 of the air bladder 22, as shown in
The display device 50 includes a display, an indicator, and the like, and displays predetermined information such as blood pressure measurement results in accordance with a control signal from the CPU 100.
The operation unit 52 includes a measurement start switch 52A for receiving an instruction to start measuring the blood pressure, and a record calling switch 52B for calling a blood pressure measurement result stored in the memory. The switches 52A and 52B input operation signals corresponding to user instructions to the CPU 100.
The memory 51 stores data of programs for controlling the blood pressure monitor 1, data used to control the blood pressure monitor 1, setting data for setting various functions of the blood pressure monitor 1, data of measurement results of blood pressure values, and the like. Also, the memory 51 is used as a work memory or the like for when a program is executed.
The CPU 100 performs control for driving the pump 32 and the valve 33 according to an operation signal from the operation unit 52, in accordance with a program for controlling the blood pressure monitor 1, which is stored in the memory 51. Also, based on the signal from the pressure sensor 31, the CPU 100 calculates the blood pressure values and controls the display device 50 and the memory 51.
The power source unit 53 supplies power to the CPU 100, the pressure sensor 31, the pump 32, the valve 33, the display device 50, the memory 51, the oscillation circuit 310, the pump driving circuit 320, and the valve driving circuit 330.
The pump 32, the valve 33, and the pressure sensor 31 are connected via a common air tube 10A to the air bladder 22 contained in the cuff 20. The pump 32 supplies air to the air bladder 22 through the air tube 10A in order to increase the pressure (cuff pressure) in the air bladder 22 contained in the cuff 20. The valve 33 is a solenoid valve that is controlled to open and close through energization, and is used to control the cuff pressure by discharging or sealing the air in the air bladder 22 through the air tube 10A. The pump driving circuit 320 drives the pump 32 based on a control signal provided from the CPU 100. The valve driving circuit 330 opens and closes the valve 33 based on a control signal provided from the CPU 100.
In this example, the pressure sensor 31 is a piezoresistant pressure sensor that detects the pressure of the cuff 20 (air bladder 22) through the air tube 10A and outputs the pressure as a cuff pressure signal (denoted by reference numeral Pc) in a time series. The oscillation circuit 310 oscillates based on an electrical signal value obtained based on a change in electrical resistance caused by the piezoresistant effect from the pressure sensor 31, and outputs a frequency signal having a frequency corresponding to the electrical signal value of the pressure sensor 31 to the CPU 100.
When the blood pressure monitor 1 (cuff 20) is attached to the wrist 90 serving as the measurement site, the wrist 90 is passed through the center of the cuff 20 as indicated by the arrow A in
In the blood pressure monitor 1, the blood pressure values of the measurement subject are measured by the CPU 100 through an oscillometric method in accordance with the flow shown in
Specifically, when the measurement start switch 52A is pressed (turned on), the blood pressure monitor 1 starts blood pressure measurement as shown in
When the blood pressure measurement is started, first, the CPU 100 closes the valve 33 via the valve driving circuit 330, and thereafter performs control for driving the pump 32 via the pump driving circuit 320 and sending air to the air bladder 22. Accordingly, the air bladder 22 swells and the cuff pressure gradually increases (step ST101). At this time, the first fluid bladder region A1 and the second fluid bladder region A2 of the air bladder 22 are inflated to the same pressure and swell.
When the cuff pressure is increased and reaches a predetermined pressure (YES in step ST102), the CPU 100 performs control for stopping the pump 32 via the pump driving circuit 320 and thereafter gradually open the valve 33 via the valve driving circuit 330. Accordingly, the air bladder 22 contracts and the cuff pressure gradually decreases (step ST103).
Here, the predetermined pressure is a pressure that is sufficiently higher than the systolic blood pressure of the measurement subject (e.g., systolic blood pressure+30 mmHg), and is stored in advance in the memory 51, or is determined by the CPU 100 estimating the systolic blood pressure using a predetermined calculation equation during increase of the cuff pressure (e.g., see JP 2001-70263A).
Also, regarding the pressure reduction rate, the target pressure reduction rate is set during inflation of the cuff, and the CPU 100 controls the opening degree of the valve 33 so as to achieve the target pressure reduction rate (see JP 2001-7026A).
In the pressure reduction process, the pressure sensor 31 detects the pressure of the cuff 20 and outputs the cuff pressure signal Pc. Based on the cuff pressure signal Pc, the CPU 100 applies a known algorithm using an oscillometric method and calculates the blood pressure values (systolic blood pressure and diastolic blood pressure) (step ST104). Note that the calculation of the blood pressure values is not limited to the pressure reduction process and may be performed in the pressure increase process.
When the blood pressure values are calculated and determined (YES in step ST105), the CPU 100 performs control for displaying the calculated blood pressure values on the display device 50 (step ST106) and storing the blood pressure values in the memory 51 (step ST107).
When the measurement ends, the CPU 100 performs control for opening the valve 33 via the valve driving circuit 330 and discharging the air in the air bladder 22 of the cuff 20 (step ST108).
In the case of performing the blood pressure measurement in this way, in the blood pressure monitor 1, when the first fluid bladder region A1 and the second fluid bladder region A2 are inflated to a certain pressure (the same pressure) Pc1 as shown in
Also, in this example, during inflation for blood pressure measurement, in order to control the cuff pressure Pc, the CPU 100 mounted in the blood pressure monitor main body 10 need only control the supply of air to the air bladder 22 (includes the first and second air bladder regions A1 and A2) using the pump 32 and the discharge of air from the air bladder 22 using the valve 33. Accordingly, control of the cuff pressure Pc is simplified compared to the case of including an element that expands or swells due to action of a different type than the fluid bladder, such as an actuator, for example, instead of the second fluid bladder region A2 as the expansion region corresponding to the half surface 90b on the back side.
In the example above, there is one child bladder 24 included in the air bladder 22, but there is no limitation to this. Two or more child bladders 24 may be overlaid on the parent bladder 23 in the thickness direction Z. In this case, through holes 49 are formed in sheets that are mutually adjacent to the multiple child bladders, and the air serving as the fluid can flow from the child bladder 24 on the uppermost level, to which the nipple is attached, to the parent bladder 23 on the lowermost level. In this case, when the second fluid bladder region A2 swells in the thickness direction Z, the stroke amount of the second fluid bladder region A2 increases to a level corresponding to the parent bladder 23 and the two or more child bladders 24. As a result, the second fluid bladder region A2 swells in the thickness direction Z by an even larger stroke amount. As a result, the measured values for blood pressure measured through inflation using the cuff 20 can be brought even closer to the true values and measurement accuracy can be further increased.
Second Embodiment
As shown in
In this example, as can be understood from
A ring 80 having a substantially oval shape is attached to the right end 20E′ in
An air bladder 22′ serving as a fluid bladder for compressing the wrist 90 is contained in the cuff 20′ spanning from the wide portion 20C′ to the narrow portion 20F′.
The air bladder 22′ includes an approximately rectangular wide portion 22C′ that is contained in the wide portion 20C′ of the cuff 20′, and a band-shaped narrow portion 22F′ that is continuous with the wide portion 22C′ and extends to the left side in
Here, the portion (included in the narrow portion 20F′) of the air bladder 22′ extending in the lengthwise direction Y, the portion corresponding to the half surface 90a on the palm side, is referred to as the first fluid bladder region A1′. On the other hand, the portion (approximately corresponds to the wide portion 20C′) of the air bladder 22′ that corresponds to the half surface 90b on the back side is referred to as the second fluid bladder region A2′.
In the case of producing the air bladder 22′, an approximately flat sheet to which a nipple 45 is attached through welding (or adhesion) and another approximately flat sheet are made to oppose each other in the thickness direction Z, and are welded (or adhered) with the opposing edge portions overlapped facing outward through a known means, along the outline indicated by the broken line in
The cross section (cross section obtained by cutting along the width direction X) of the obtained air bladder 22′ is about the same as the cross section shown in
The air bladder 22′ is contained in the cuff 20′ with the nipple 45 protruding through the outer cloth 20A. When the cuff 20′ is joined to the blood pressure monitor main body 10, in this example, the nipple 45 and the air tube 10A (see
When the cuff 20′ is attached to the wrist 90 serving as the measurement site, the wrist 90 is passed through the center of the cuff 20′ similarly to the manner indicated by the arrow A in
In the blood pressure monitor 1′, the blood pressure values of the measurement subject are measured through an oscillometric method in accordance with the flow shown in
In the case of performing blood pressure measurement in this way, in the blood pressure monitor 1′, when the first fluid bladder region A1′ and the second fluid bladder region A2′ are inflated to the certain pressure (the same pressure) Pc1 as shown in
Also, in this example, similarly to the description of the first embodiment, the CPU 100 mounted in the blood pressure monitor main body 10 need only control the supply of air to the air bladder 22′ (includes the first and second fluid bladder regions A1′ and A2′) using the pump 32 and the discharge of air from the air bladder 22′ using the valve 33 in order to control the cuff pressure Pc during inflation for blood pressure measurement. Accordingly, control of the cuff pressure Pc is simplified compared to the case of including an element that expands or swells due to action of a different type than the fluid bladder, such as an actuator, for example, instead of the second fluid bladder region A2′ as the expansion region corresponding to the half surface 90b on the back side.
Note that the configuration of the second embodiment may be combined with the configuration of the first embodiment. That is, in the cuff 20 of
In the examples shown in
In this example, as can be understood from
An air bladder 22″ serving as a fluid bladder for compressing the wrist 90 is included in the cuff 20″, spanning from the portion 20E″ near the right end to the transition portion 20F1″.
The outlines of the edge portions 22c″ and 22d″ on both sides in the width direction X of the air bladder 22″ are formed to be approximately the same as the outlines of the corresponding edge portions of the cuff 20″. The dimension W1″ in the width direction X of the air bladder 22″ is set to be about 5 mm smaller than the width direction dimension W″ of the cuff 20″.
Similarly to the air bladder 22′ in
The air bladder 22″ is produced using the same procedure as the air bladder 22′ in
Also, the cuff 20″ is joined to the blood pressure monitor main body 10 using the same procedure as the cuff 20′ in
According to the blood pressure monitor including the cuff 20″, when the first fluid bladder region A1″ and the second fluid bladder region A2″ are inflated to a certain pressure (the same pressure) Pc1, similarly to the description of
Also, in this example, similarly to the description of the first embodiment, the CPU 100 mounted in the blood pressure monitor main body 10 need only control the supply of air to the air bladder 22″ (includes the first and second fluid bladder regions A1″ and A2″) using the pump 32 and the discharge of air from the air bladder 22″ using the valve 33 in order to control the cuff pressure Pc during inflation for blood pressure measurement. Accordingly, control of the cuff pressure Pc is simplified compared to the case of including an element that expands or swells due to action of a different type than the fluid bladder, such as an actuator, for example, instead of the second fluid bladder region A2″ as the expansion region corresponding to the half surface 90b on the back side.
In the examples shown in
For example, it is possible to use a structure with a cross section (cross section obtained by cutting along the width direction X) shown in
With the structure of the cross section shown in
Also, in this example, the thickness (in this example, 0.1 mm) of the side portions A2e and A2f of the second fluid bladder region A2′ is thinner than the thickness (in this example, 1.0 mm) of the sheet 42 serving as the sheet portion on the side away from the wrist 90. Accordingly, when the second fluid bladder region A2′ swells in the thickness direction Z, it is easier for the side portions A2e and A2f of the second fluid bladder region A2′ to stretch. As a result, the stroke amount of the second fluid bladder region A2′ in the thickness direction Z is even larger. Accordingly, the measurement accuracy can be further increased.
Also, in addition to this (or instead of this), the hardness of the side portions A2e and A2f of the second fluid bladder region A2′ may be made smaller than the hardness of the sheet 42 serving as the sheet portion away from the wrist 90. For example, silicone resin (or polyurethane resin) with a hardness of 50 is used as the material of the sheet 41, and polyurethane resin with a hardness of 80 is used as the material of the sheet 42. In this case, when the second fluid bladder region A2′ swells in the thickness direction Z, it is even easier for the side portions A2e and A2f of the second fluid bladder region A2′ to stretch. As a result, the stroke amount of the second fluid bladder region A2′ in the thickness direction Z is even larger. Accordingly, the measurement accuracy can be further increased.
In the example shown in
For example, it is possible to use a structure with a cross section (cross section obtained by cutting along the width direction X) shown in
With the structure of the cross section shown in
Also, in this example, the thickness (in this example, 0.1 mm) of the side portions A2e′ and A2f′ of the second fluid bladder region A2′ is thinner than the thickness (in this example, 1.0 mm) of the sheet 42 serving as the sheet portion on the side away from the wrist 90. Accordingly, when the second fluid bladder region A2′ swells in the thickness direction Z, it is easier for the side portions A2e′ and A2f′ of the second fluid bladder region A2′ to stretch. Furthermore, in this example, the side portions A2e′ and A2f′ of the second fluid bladder region A2′ are bellows-shaped in their natural state. Accordingly, when the second fluid bladder region A2′ swells in the thickness direction Z, the bellows-shaped side portions A2e′ and A2f′ stretch easily. As a result, the stroke amount of the second fluid bladder region A2′ in the thickness direction Z is even larger. Accordingly, the measurement accuracy can be further increased.
Note that in this example, the side portions A2e′ and A2f′ of the second fluid bladder region A2′ are bellows-shaped in their natural state, but they may be folded in a zig-zag shape. In this case as well, a similar effect can be exhibited.
The above-described Modified Example 2 and Modified Example 3 can be applied not only to the example shown in
Also, in the above-described examples, the material of the sheets forming the air bladders 22, 22′, and 22″ is polyurethane resin, but there is no limitation thereto. The material of the air bladder 22 need only be elastic (in particular, be stretchable and bendable) and be a sturdy material, and for example, silicone resin may be used thereas.
Verification Test
The inventor of the present invention performed a test for verifying the result of the invention by using a commercially-available wrist-type blood pressure monitor (HEM-6310F manufactured by Omron Healthcare Corporation) (indicated by reference numeral 6310) as a standard, on a blood pressure monitor including a cuff of a first comparative example (indicated by reference numeral 820), a blood pressure monitor including the cuff of a second comparative example (indicated by reference numeral 920), and the blood pressure monitor 1 including the cuff 20 of the first embodiment.
As shown in
As shown in
As shown approximately in
As shown in
As can be understood from
Although the measured values (reference sign □) obtained by the blood pressure monitor 9000 including the cuff 920 of the second embodiment are improved compared to those of the first comparative example, they vary significantly and are still higher than the measured values obtained by the standard blood pressure monitor 6310. The differences obtained by subtracting the measured values (simultaneously measured) obtained by the blood pressure monitor 6310 from the measured values obtained by the blood pressure monitor 9000 were 11.8 mmHg on average, 24 mmHg maximum, and 4 mmHg minimum.
The measured values (reference sign Δ) obtained by the blood pressure monitor 1 including the cuff 20 of the first embodiment vary less than those of the second comparative example and are further improved. The differences obtained by subtracting the measured values (those measured at the same time) obtained by the blood pressure monitor 6310 from the measured values obtained by the blood pressure monitor 1 were 6.0 mmHg on average, 9 mmHg maximum, and 1 mmHg minimum.
Thus, it can be verified that it is possible to bring the measured values for the blood pressure close to the true values and the measurement accuracy can be increased according to the blood pressure monitor 1 including the cuff 20 of the first embodiment.
Third Embodiment; Blood Pressure Measurement Method
In the above-described embodiments, according to a distinctive configuration of the blood pressure measurement cuff, during inflation for blood pressure measurement, the stroke amount by which the second fluid bladder region swells is larger in the thickness direction than the stroke amount by which the first fluid bladder region swells. However, there is no limitation to this. For example, the method of inflation may be controlled such that the stroke amount by which the air bladder 26 swells is larger in the thickness direction than the stroke amount by which the air bladder 25 swells during inflation for blood pressure measurement, while a known blood pressure measurement cuff 120 (includes the air bladder 25 serving as the first fluid bladder corresponding to the half surface 90a on the palm side of the wrist 90 and the air bladder 26 serving as the second fluid bladder corresponding to the half surface 90b on the back side) shown in
Note that as shown in
With this blood pressure measurement method, the blood pressure values of the measurement subject are measured by the CPU 100 in the blood pressure monitor main body 110 using an oscillometric method in accordance with the flow shown in
Specifically, when the measurement start switch 52A is pressed (turned on), the blood pressure monitor 101 starts blood pressure measurement as shown in
Upon starting the blood pressure measurement, first, the CPU 100 closes the valves 33 and 33′ via the valve drive circuits 330 and 330′, and thereafter drives the pumps 32 and 32′ via the pump driving circuits 320 and 320′ so as to start control for inflating the air bladders 25 and 26 (step ST201). Here, the supply of air to the air bladder 25 serving as the first fluid bladder is set to a fixed flow rate, such as 10 sccm (standard cc/min), for example. On the other hand, the supply of air to the air bladder 26 serving as the second fluid bladder is subjected to inflation control at a constant rate, such as 5.5 mmHg/sec, for example (step ST202). Accordingly, as indicated in the period from time 0 to t1 in
Next, the CPU 100 determines whether or not the pressure P2 of the air bladder 26 has reached a predetermined pressure Pt (in this example, Pt=20 mmHg) based on the output of the pressure sensor 31′ (step ST203 in
Next, the CPU 100 determines whether or not the difference (P2−P1) between the pressure P2 of the air bladder 26 and the pressure P1 of the air bladder 25 is less than or equal to a predetermined threshold (denoted by ΔP) based on the outputs of the pressure sensors 31 and 31′ (step ST205 of
In this example, in the process of inflation, the CPU 100 detects a pulsewave signal Pm (varying component of the pressure P1) based on the output of the pressure sensor 31 and calculates the blood pressure values (systolic blood pressure and diastolic blood pressure) by applying a known algorithm according to the oscillometric method (steps ST207 and ST208 in
When the blood pressure values are calculated and decided (YES in step ST208), the CPU 100 performs control for displaying the calculated pressure values on the display device 50 (step ST106) and storing the blood pressure values in the memory 51 (step ST107), similarly to the description given with reference to
When measurement ends (time te in
In the case of performing blood pressure measurement in this way, as shown in
Modified Example of Blood Pressure Measurement Method
The above-described blood pressure measurement method can also be executed using the blood pressure monitor 101′ including the cuff 120′ shown in
With the cuff 120′ shown in
With the blood pressure monitor 101′, the supply of air to the air bladder 26 serving as the second fluid bladder is subjected to inflation control at a constant rate by the CPU 100 during inflation for blood pressure measurement. The air bladder 25 serving as the first fluid bladder receives a supply of air from the air bladder 26 via the orifice 29. Accordingly, the pressure P1 of the air bladder 25 becomes larger than the pressure P2 of the air bladder 26 later because of the fluid resistance indicated by the orifice 29. As a result, the pressure P1 of the air bladder 25 and the pressure P2 of the air bladder 26 change approximately similarly to those shown in
With the blood pressure monitor 101′, the elements 32, 33, 320, and 330 for controlling the pressure of the air bladder 25 can be omitted, and thus the configuration of the main body 110′ can be simplified.
With the above-described embodiments, the measurement site was the wrist 90, but there is no limitation to this. The measurement site may be another site, such as an upper arm.
Also, in the above-described embodiments, the blood pressure measurement cuff was of a type that is worn around the measurement site by being folded over through a ring, but there is no limitation to this. The blood pressure measurement cuff may be of a type that is worn by being wrapped around a measurement site in one direction in a spiral shape.
Also, in the above-described embodiments, the blood pressure measurement cuff was constituted by containing an air bladder serving as a fluid bladder in a band-shaped member. However, there is no limitation to this. The fluid bladder is made of elastomer, for example, and the fluid bladder may be constituted by a blood pressure measurement cuff.
Also, the fluid was air, but there is no limitation to this. The fluid may be a fluid that can inflate and deflate the fluid bladder, such as nitrogen.
While the present invention has been described with reference to specific embodiments, the present invention is not limited to these embodiments, and many modifications can be made without departing from the technical idea of the disclosed invention. The multiple above-described embodiments can be achieved independently or used in combination with each other. Also, although the various characteristics of the different embodiments can be achieved independently, it is also possible to combine characteristics of the different embodiments.
1, 101, 101′ Blood pressure monitor
10, 110, 110′ Main body
20, 20′, 20″, 120, 120′ Cuff
22, 22′, 22″, 25, 26 Air bladder
23 Parent bladder
24 Child bladder
A1, A1′, A1″ First fluid bladder region
A2, A2′, A2″ Second fluid bladder region
45, 46 Nipple
Number | Date | Country | Kind |
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2015-126954 | Jun 2015 | JP | national |
Number | Name | Date | Kind |
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20010016692 | Itonaga | Aug 2001 | A1 |
20040034308 | Inoue | Feb 2004 | A1 |
20100024811 | Henry | Feb 2010 | A1 |
20100268092 | Kobayashi | Oct 2010 | A1 |
20120240377 | Ashida | Sep 2012 | A1 |
Number | Date | Country |
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1785116 | Jun 2006 | CN |
1792320 | Jun 2006 | CN |
102688026 | Sep 2012 | CN |
1075846 | Apr 2001 | EP |
H09-117419 | May 1997 | JP |
2003-024286 | Jan 2003 | JP |
2003-144398 | May 2003 | JP |
99055400 | Nov 1999 | WO |
Entry |
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International Search Report issued in PCT/JP2016/058834, dated Jun. 21, 2016 (2 pages). |
Witten Opinion issued in PCT/JP2016/058834, dated Jun. 21, 2016 (5 pages). |
Decision to Grant a Patent issued in Japanese Application No. 2015-126954, dated Jun. 6, 2017 (3 pages). |
Office Action issued in Chinese Application No. 201680025713.0, dated Sep. 18, 2018 (15 pages). |
Office Action in counterpart Chinese Patent Application No. 201680025713.0, dated Mar. 15, 2019 (12 pages). |
Number | Date | Country | |
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20180177414 A1 | Jun 2018 | US |
Number | Date | Country | |
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Parent | PCT/JP2016/058834 | Mar 2016 | US |
Child | 15850603 | US |