JP2021030037A - Blood pressure manometer, blood pressure calculation method and program - Google Patents

Abstract

To provide a blood pressure manometer capable of stably and accurately calculating a blood pressure value, when performing blood pressure measurement according to an interrupted blood pressure measurement instruction which is different from a predetermined schedule in a night blood pressure measurement mode.SOLUTION: A blood pressure manometer is configured so that, when a mode is switched from a normal blood pressure measurement mode to a night blood pressure measurement mode by a mode operation part (S11), an algorithm for blood pressure calculation by an oscillometric method is switched from an algorithm for sitting to an algorithm for dorsal position (S12). The algorithm which is set currently for blood pressure calculation by the oscillometric method is used for calculating a blood pressure value (S17).SELECTED DRAWING: Figure 6

Description

The present invention relates to a sphygmomanometer, and more particularly to a sphygmomanometer having a normal blood pressure measurement mode and a nighttime (sleeping) blood pressure measurement mode. The present invention also relates to a blood pressure calculation method for calculating blood pressure by such a sphygmomanometer. The present invention also relates to a program for causing a computer to execute such a blood pressure calculation method.

Conventionally, as a blood pressure monitor of this type, for example, in Patent Document 1 (International Publication No. 2018/1687797), it is appropriately determined whether or not the measurement position of the blood pressure monitor is correct for each measurement posture of the sitting position and the supine position. Therefore, a device that switches the measurement posture determination condition between the normal blood pressure measurement mode and the nocturnal blood pressure measurement mode is disclosed.

Further, for example, Patent Document 2 (Japanese Unexamined Patent Publication No. 2018-153240) discloses a sphygmomanometer that corrects a blood pressure value by using height information of the sphygmomanometer measured during measurement including sleeping.

International Publication No. 2018/1687797 JP-A-2018-153240

Patent Documents 1 and 2 also disclose that these techniques are applied to a wrist-type blood pressure monitor worn on a wrist (forearm). However, since the wrist type sphygmomanometer has a high degree of freedom in position, there is a problem that the process of accurately measuring or determining the measurement posture during bedtime is not stable.

Therefore, an object of the present invention is to provide a sphygmomanometer capable of stably and accurately calculating a blood pressure value in a sphygmomanometer having a normal blood pressure measurement mode and a nighttime (sleeping) blood pressure measurement mode. Another object of the present invention is to provide a blood pressure calculation method capable of stably and accurately calculating blood pressure by such a sphygmomanometer. Another object of the present invention is to provide a program for causing a computer to execute such a blood pressure calculation method.

In order to solve the above problems, the sphygmomanometer of this disclosure is
A sphygmomanometer that measures blood pressure by the oscillometric method by temporarily pressing the wrist as the measurement site with a blood pressure measurement cuff.
A measurement instruction input unit for inputting blood pressure measurement instructions,
A mode between a normal blood pressure measurement mode in which blood pressure is measured according to a blood pressure measurement instruction input by the measurement instruction input unit and a nighttime blood pressure measurement mode in which blood pressure measurement is automatically started according to a predetermined schedule. Mode operation unit for inputting instructions to switch between
As an algorithm for calculating blood pressure by the oscillometric method, an algorithm storage unit that stores an algorithm for sitting and an algorithm for supine position,
When the normal blood pressure measurement mode is switched to the nocturnal blood pressure measurement mode by the mode operation unit, the algorithm for calculating the blood pressure by the oscillometric method is set by switching from the algorithm for the sitting position to the algorithm for the lying position. Switching part and
When the blood pressure measuring cuff is in the pressurizing process or the depressurizing process, the blood pressure value is calculated based on the pressure of the blood pressure measuring cuff using the algorithm currently set for calculating the blood pressure by the oscillometric method. It is characterized by having a blood pressure calculation unit for calculating.

In the present specification, the "measurement instruction input unit" and the "mode operation unit" may be, for example, a switch provided on the main body of the sphygmomanometer and accept a switch-on by the user as an instruction. It may be configured by a communication unit that receives instructions via wireless communication from a smartphone or the like existing outside the sphygmomanometer.

The "algorithm for calculating blood pressure by the oscillometric method" is to set an envelope for the sequence of pulse wave amplitude obtained from the cuff pressure when the blood pressure measurement cuff is in the pressurization process or the depressurization process. , Set a predetermined ratio of threshold levels to the maximum value of the envelope (including systolic and diastolic thresholds), and the envelope crosses those thresholds. It means an algorithm that calculates the cuff pressure at that time as systolic blood pressure (systolic blood pressure) and diastolic blood pressure (diastolic blood pressure), respectively. The difference between the sitting algorithm and the supine algorithm is typically the difference in the threshold level (eg, the difference in the ratio of the envelope to the maximum value, or the plus or minus number for a certain ratio (for example). Offset value)).

The "currently set algorithm" means an algorithm set at the time of blood pressure calculation by the blood pressure calculation unit.

In the sphygmomanometer of this disclosure, the algorithm storage unit stores an algorithm for the sitting position and an algorithm for the supine position as an algorithm for calculating the blood pressure by the oscillometric method. When the mode operation unit switches from the normal blood pressure measurement mode to the nocturnal blood pressure measurement mode, the first switching unit changes the algorithm for calculating blood pressure by the oscillometric method from the algorithm for sitting position to the algorithm for lying position. Switch and set. In the nighttime blood pressure measurement mode, blood pressure measurement is automatically started according to a predetermined schedule. That is, the blood pressure measurement cuff temporarily presses the measurement site according to a predetermined schedule. The blood pressure calculation unit is an algorithm currently set for calculating blood pressure by the oscillometric method based on the pressure of the blood pressure measuring cuff when the blood pressure measuring cuff is in the pressurizing process or the depressurizing process (this). At this point, the blood pressure value is calculated using the recumbent position algorithm). In the nocturnal blood pressure measurement mode, the subject is usually expected to be in the supine position. Therefore, by using the above algorithm for the supine position, the blood pressure values (maximum blood pressure and diastolic blood pressure) can be calculated stably and accurately.

In addition, since this sphygmomanometer is a type that presses the wrist as the measurement site, it is expected that the degree of disturbing the subject's sleep is less than that of the type that presses the upper arm (Imai et al., “Development and evaluation of a home nocturnal blood pressure monitoring system using a wrist-cuff device”, Blood Pressure Monitoring 2018, 23, P318-326). Therefore, this sphygmomanometer is suitable for nighttime (sleeping) blood pressure measurement.

The sphygmomanometer of one embodiment responds to the interrupted blood pressure measurement instruction when a blood pressure measurement instruction is input by an interrupt by the measurement instruction input unit in addition to the predetermined schedule in the nighttime blood pressure measurement mode. For blood pressure measurement, a second switching unit is provided for switching and setting an algorithm for calculating blood pressure by the oscillometric method from the algorithm for the supine position to the algorithm for the sitting position.

Even while the sphygmomanometer is in the nighttime blood pressure measurement mode, the user instructs the blood pressure measurement by interruption, for example, by pressing the measurement switch provided on the sphygmomanometer, in addition to the predetermined schedule. I have something to do. At this time, the subject is expected to be in the sitting position rather than in the supine position. Therefore, when the blood pressure is measured according to the blood pressure measurement instruction, if the blood pressure value is calculated by using the supine position algorithm as it is, there arises a problem that the measurement accuracy is not good. Therefore, in the sphygmomanometer of this one embodiment, when a blood pressure measurement instruction is input by an interrupt by the measurement instruction input unit in addition to the predetermined schedule in the nighttime blood pressure measurement mode, the second switching unit is activated. , In order to measure the blood pressure in response to the blood pressure measurement instruction of the interruption, the algorithm for calculating the blood pressure by the oscillometric method is set by switching from the above-mentioned algorithm for the supine position to the above-mentioned algorithm for the sitting position. In that state, in order to measure the blood pressure in response to the blood pressure measurement instruction of the interruption, the blood pressure measurement cuff temporarily presses the part to be measured. The blood pressure calculation unit is an algorithm currently set for calculating blood pressure by the oscillometric method based on the pressure of the blood pressure measuring cuff when the blood pressure measuring cuff is in the pressurizing process or the depressurizing process (this). At this point, the blood pressure value is calculated using the sitting algorithm). Even in the nocturnal blood pressure measurement mode, when a blood pressure measurement instruction is input by an interrupt by the measurement instruction input unit, the subject is expected to be in a sitting position rather than a supine position as described above. .. Therefore, by using the above-mentioned algorithm for sitting position, the blood pressure value (maximum blood pressure and diastolic blood pressure) can be calculated stably and accurately. Therefore, according to the sphygmomanometer of this one embodiment, in the nighttime blood pressure measurement mode, the blood pressure value is stabilized when the blood pressure is measured according to the interrupted blood pressure measurement instruction separately from the predetermined schedule. It can be calculated accurately.

In the sphygmomanometer of one embodiment, when the blood pressure measurement according to the blood pressure measurement instruction of the interruption is completed, as long as the blood pressure measurement is still scheduled according to the schedule, the algorithm for calculating the blood pressure by the oscillometric method is used for the sitting position. It is characterized in that it is provided with a third switching unit for switching and setting from the above-mentioned algorithm for the supine position.

In the sphygmomanometer of this embodiment, when the blood pressure measurement according to the blood pressure measurement instruction is completed, the third switching unit is used for calculating the blood pressure by the oscillometric method as long as the blood pressure measurement is still scheduled according to the schedule. The algorithm is set by switching from the sitting position algorithm to the lying position algorithm. Therefore, after the blood pressure measurement according to the blood pressure measurement instruction of the interruption is completed, the blood pressure measurement is automatically started according to the schedule. That is, according to the above schedule, the blood pressure measurement cuff temporarily presses the measurement site. The blood pressure calculation unit is an algorithm currently set for calculating blood pressure by the oscillometric method based on the pressure of the blood pressure measuring cuff when the blood pressure measuring cuff is in the pressurizing process or the depressurizing process (this). At this point, the blood pressure value is calculated using the recumbent position algorithm). In the nocturnal blood pressure measurement mode, as described above, the subject is usually expected to be in the supine position. Therefore, after the blood pressure measurement according to the blood pressure measurement instruction of the interruption is completed, the blood pressure value (maximum blood pressure and diastolic blood pressure) can be calculated stably and accurately by using the supine position algorithm.

In the sphygmomanometer of one embodiment, when all the blood pressure measurements defined in the above schedule are completed, the algorithm for calculating the blood pressure by the oscillometric method is set by switching from the algorithm for the supine position to the algorithm for the sitting position. It is characterized by having a fourth switching unit.

In the sphygmomanometer of this embodiment, when all the blood pressure measurements defined in the above schedule are completed, the fourth switching unit changes the algorithm for calculating the blood pressure by the oscillometric method from the algorithm for the supine position to the algorithm for the sitting position. Switch to the algorithm of and set. Therefore, after the end of the nocturnal blood pressure measurement mode, for example, when the normal blood pressure measurement mode is started by default, the blood pressure calculation unit uses the sitting algorithm for the blood pressure calculation by the oscillometric method to obtain the blood pressure value. Can be calculated. Therefore, the blood pressure calculation in the normal blood pressure measurement mode can be correctly executed.

In one embodiment of the sphygmomanometer
Equipped with a main body provided integrally with the above blood pressure measurement cuff,
The measurement instruction input unit and the mode operation unit include switches provided on the outer surface of the main body, respectively.
The main body is characterized by incorporating the algorithm storage unit, each switching unit, a pressure control unit that controls the pressure of the blood pressure measurement cuff, and the blood pressure calculation unit.

Here, the "pressure control unit" drives and controls, for example, a pump that supplies a pressurizing fluid to the blood pressure measuring cuff, a valve that exhausts the fluid from the blood pressure measuring cuff, and these pumps / valves. Contains elements.

The sphygmomanometer of this embodiment can be integrally and compactly configured as a wrist-type sphygmomanometer. Therefore, the handling by the user becomes convenient.

In another aspect, the blood pressure calculation method of this disclosure is
It is a blood pressure calculation method for a sphygmomanometer that temporarily presses the wrist as a measurement site with a blood pressure measurement cuff and measures the blood pressure by the oscillometric method.
The above blood pressure monitor
A measurement instruction input unit for inputting blood pressure measurement instructions,
A mode between a normal blood pressure measurement mode in which blood pressure is measured according to a blood pressure measurement instruction input by the measurement instruction input unit and a nighttime blood pressure measurement mode in which blood pressure measurement is automatically started according to a predetermined schedule. Mode operation unit for inputting instructions to switch between
As an algorithm for calculating blood pressure by the oscillometric method, an algorithm storage unit that stores an algorithm for sitting and an algorithm for supine position,
With
The above blood pressure calculation method is
When the normal blood pressure measurement mode is switched to the nocturnal blood pressure measurement mode by the above mode operation unit, the algorithm for calculating blood pressure by the oscillometric method is set by switching from the algorithm for sitting position to the algorithm for lying position.
When the blood pressure measuring cuff is in the pressurizing process or the depressurizing process, the blood pressure value is calculated based on the pressure of the blood pressure measuring cuff using the algorithm currently set for calculating the blood pressure by the oscillometric method. It is characterized by calculating.

According to this blood pressure calculation method, the blood pressure value can be calculated stably and accurately when the blood pressure is measured according to the interrupted blood pressure measurement instruction in the nighttime blood pressure measurement mode, in addition to the predetermined schedule.

In yet another aspect, the program of this disclosure is a program for causing a computer to execute the above-mentioned blood pressure calculation method.

The blood pressure calculation method can be carried out by causing a computer to execute the program of this disclosure.

As is clear from the above, according to the blood pressure monitor and the blood pressure calculation method of the present disclosure, the blood pressure value is stably accurate in the blood pressure monitor having the above-mentioned normal blood pressure measurement mode and the above-mentioned nighttime (sleeping) blood pressure measurement mode. It can be calculated well. Also, according to the program of this disclosure, such a blood pressure calculation method can be executed by a computer.

It is a figure which shows the appearance of the wrist type sphygmomanometer of one Embodiment of this invention. It is a figure which shows the block structure of a sphygmomanometer. It is a figure which shows the mode in which the said sphygmomanometer was attached to the left wrist as a measurement site. It is a figure which shows the sitting position as a measurement posture. It is a figure which shows the supine position as a measurement posture. It is a figure which shows the operation flow at the time of performing the blood pressure measurement in a normal blood pressure measurement mode by the said blood pressure monitor. It is a figure which shows the operation flow when the blood pressure is measured in the nighttime blood pressure measurement mode by the said sphygmomanometer. FIG. 7A is a diagram showing the passage of time of the cuff pressure PC accompanying the blood pressure measurement. FIG. 7B is a diagram showing the time passage of the pulse wave signal SM accompanying the blood pressure measurement. FIG. 7C is a diagram showing an envelope ENV set for a sequence of pulse wave amplitudes formed by the pulse wave signal SM. It is a figure explaining the method of the blood pressure calculation in a nocturnal blood pressure measurement mode.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Structure of blood pressure monitor)
FIG. 1 shows the appearance of the wrist type sphygmomanometer 100 according to the embodiment of the present invention. The sphygmomanometer 100 is roughly divided into a blood pressure measuring cuff 20 to be attached to the left wrist 90 (see FIG. 3 described later) as a measurement site, and a main body 10 integrally attached to the cuff 20. ing.

The cuff 20 is a general one for a wrist type sphygmomanometer, and has an elongated band shape so as to surround the left wrist 90 along the circumferential direction. The cuff 20 contains a fluid bag 22 (see FIG. 2) for pressing the left wrist 90. In order to keep the cuff 20 in an annular shape at all times, a carla having appropriate flexibility may be provided in the cuff 20.

As shown in FIG. 3, the main body 10 is integrally attached to a portion substantially at the center of the strip-shaped cuff 20 in the longitudinal direction. In this example, the portion to which the main body 10 is attached is planned to correspond to the palm side surface (palm side surface) 90a of the left wrist 90 in the mounted state.

The main body 10 has a flat, substantially rectangular parallelepiped shape along the outer peripheral surface of the cuff 20. The main body 10 is formed to be small and thin so as not to interfere with the sleep of the user (in this example, the subject; the same applies hereinafter). Further, the corners of the main body 10 are rounded (the corners are rounded).

As shown in FIG. 1, on the surface (top surface) of the outer surface of the main body 10 farthest from the left wrist 90, a display 50 forming a display screen and an operation unit 52 for inputting an instruction from the user are input. And are provided.

In this example, the display 50 comprises an LCD (Liquid Crystal Display) and displays predetermined information according to a control signal from a CPU (Central Processing Unit) 110 described later. In this example, the systolic blood pressure (unit: mmHg), the diastolic blood pressure (unit: mmHg), and the pulse (unit: beat / minute) are displayed. The display 50 may consist of an organic EL (Electro Luminescence) display or may include an LED (Light Emitting Diode).

The operation unit 52 inputs an operation signal according to an instruction by the user to the CPU 110 described later. In this example, the operation unit 52 receives a measurement switch 52A as a measurement instruction input unit for receiving a blood pressure measurement instruction by the user, and an instruction to switch the mode between the normal blood pressure measurement mode and the nighttime blood pressure measurement mode. It includes a night measurement switch 52B as a mode operation unit of the above. Here, the "normal blood pressure measurement mode" means a mode in which, when a blood pressure measurement instruction is input by the measurement switch 52A, the blood pressure is measured in response to the blood pressure measurement instruction. The "nighttime blood pressure measurement mode" means a mode in which blood pressure measurement is automatically started according to a predetermined schedule so that the user can measure the blood pressure value during sleep. The predetermined schedule refers to a plan for measuring at a fixed time such as 1:00, 2:00, or 3:00 at midnight, or a plan for measuring once every two hours after the night measurement switch 52B is pressed.

Specifically, in this example, the measurement switch 52A and the night measurement switch 52B are both momentary type (self-recovery type) switches, and are turned on only while they are pressed down and turned off when they are released. go back.

Once the measurement switch 52A is pressed down while the sphygmomanometer 100 is in the normal blood pressure measurement mode, it means a blood pressure measurement instruction, and the cuff 20 temporarily presses the area to be measured (left wrist 90). Blood pressure measurements are performed by the metric method. When the measurement switch 52A is pressed down again during blood pressure measurement (for example, while pressurizing the cuff 20), it means an instruction to stop blood pressure measurement, and blood pressure measurement is stopped immediately.

Once the night measurement switch 52B is pressed down while the sphygmomanometer 100 is in the normal blood pressure measurement mode, it means an instruction to shift to the night blood pressure measurement mode, and the sphygmomanometer 100 measures the night blood pressure from the normal blood pressure measurement mode. Move to mode. In the nocturnal blood pressure measurement mode, as described above, blood pressure measurement by the oscillometric method is automatically started according to a predetermined schedule. If the night measurement switch 52B is pressed again while the sphygmomanometer 100 is in the nighttime blood pressure measurement mode, it means an instruction to stop the nighttime blood pressure measurement mode, and the sphygmomanometer 100 shifts from the nighttime blood pressure measurement mode to the normal blood pressure measurement mode. To do.

Even while the sphygmomanometer 100 is in the nocturnal blood pressure measurement mode, the user may instruct the blood pressure measurement by interruption by pressing the measurement switch 52A, in addition to the predetermined schedule. At that time, the blood pressure measurement is temporarily performed by the cuff 20 in response to the interrupted blood pressure measurement instruction, and the blood pressure measurement is performed by the oscillometric method.

FIG. 2 shows a block configuration of the sphygmomanometer 100.

The cuff 20 includes a fluid bag 22 for pressing the left wrist 90 as a measurement site as described above. The fluid bag 22 and the main body 10 are connected by an air pipe 39 so that the fluid can flow.

In addition to the display 50 and the operation unit 52 described above, the main body 10 includes a CPU 110 as a control unit, a memory 51 as a storage unit, a power supply unit 53, a pressure sensor 31, a pump 32, and a valve 33. And is installed. Further, the main body 10 includes an A / D conversion circuit 310 that converts the output of the pressure sensor 31 from an analog signal to a digital signal, a pump drive circuit 320 that drives the pump 32, and a valve drive circuit 330 that drives the valve 33. It is installed. The pressure sensor 31, the pump 32, and the valve 33 are commonly connected to the fluid bag 22 through the air pipe 39 so that the fluid can flow.

The memory 51 stores a program for controlling the sphygmomanometer 100, data used for controlling the sphygmomanometer 100, setting data for setting various functions of the sphygmomanometer 100, data of blood pressure value measurement results, and the like. Remember. Further, the memory 51 is used as a work memory or the like when a program is executed. In particular, in this example, the memory 51 functions as an algorithm storage unit and stores an algorithm for the sitting position and an algorithm for the supine position as an algorithm for calculating blood pressure by the oscillometric method.

Here, as shown in FIG. 4A, the “sitting position” means that a user 80 who wears a sphygmomanometer 100 on his left wrist 90 sits on a chair 97 or the like, puts his left elbow on a table 98, and puts his left wrist 90 on his trunk. On the other hand, by raising it diagonally forward (hands up, elbows down), it means a posture in which the left wrist 90 (and sphygmomanometer 100) is maintained at the height level of the heart 81. This posture is recommended to improve the accuracy of blood pressure measurement because the height difference between the left wrist 90 of the user 80 and the heart 81 can be eliminated. On the other hand, in the "supine position", as shown in FIG. 4B, a user 80 wearing a sphygmomanometer 100 on the left wrist 90 is placed on a horizontal floor surface 99 or the like with the left elbow extended along the trunk. It means lying on his back. In this posture, the height difference ΔH between the left wrist 90 (and the sphygmomanometer 100) of the user 80 and the heart 81 occurs (the height of the heart 81 is higher than the height of the left wrist 90), so that the blood pressure measurement value is measured. There will be a gap. In addition, since the left elbow is bent in the sitting position (Fig. 4A) and the left elbow is extended in the supine position (Fig. 4B), the blood pressure measurement value may deviate due to the bending and stretching of the left elbow. There is also sex. In order to eliminate the deviation of the blood pressure measurement value in the recumbent position with respect to the blood pressure measurement value in the sitting position, a blood pressure calculation algorithm for measuring the blood pressure in the recumbent position is used as opposed to the blood pressure calculation algorithm for measuring the blood pressure in the sitting position. It is desirable to change. For this reason, in this example, the memory 51 stores an algorithm for the sitting position and an algorithm for the supine position as an algorithm for calculating blood pressure by the oscillometric method. The specific method of calculating blood pressure using the algorithm for the sitting position and the algorithm for the supine position will be described later.

The CPU 110 shown in FIG. 2 controls the operation of the entire sphygmomanometer 100. Specifically, the CPU 110 acts as a pressure control unit according to a program for controlling the sphygmomanometer 100 stored in the memory 51, and drives the pump 32 and the valve 33 in response to an operation signal from the operation unit 52. Take control. Further, the CPU 110 functions as a blood pressure calculation unit, calculates a blood pressure value using an algorithm for calculating blood pressure by the oscillometric method, and controls the display 50 and the memory 51.

In this example, the power supply unit 53 includes a secondary battery, a CPU 110, a pressure sensor 31, a pump 32, a valve 33, a display 50, a memory 51, an A / D conversion circuit 310, a pump drive circuit 320, and a valve drive circuit 330. Power is supplied to each part of.

The pump 32 supplies air as a fluid to the fluid bag 22 through the air pipe 39 in order to pressurize the pressure (cuff pressure) in the fluid bag 22 contained in the cuff 20. The valve 33 is opened and closed to discharge the air from the fluid bag 22 through the air pipe 39 or to fill the fluid bag 22 with air to control the cuff pressure. The pump drive circuit 320 drives the pump 32 based on a control signal given from the CPU 110. The valve drive circuit 330 opens and closes the valve 33 based on a control signal given from the CPU 110.

The pressure sensor 31 and the A / D conversion circuit 310 function as a pressure detection unit that detects the pressure of the cuff. The pressure sensor 31 is a piezoresistive pressure sensor in this example, and outputs the pressure (cuff pressure) in the fluid bag 22 contained in the cuff 20 as an electric resistance due to the piezoresistive effect through the air pipe 39. The A / D conversion circuit 310 converts the output (electrical resistance) of the pressure sensor 31 from an analog signal to a digital signal and outputs it to the CPU 110. In this example, the CPU 110 acts as an oscillating circuit that oscillates at a frequency corresponding to the electrical resistance from the pressure sensor 31, and acquires a signal representing the cuff pressure according to the oscillating frequency.

(Blood pressure calculation method)
FIG. 5 shows an operation flow when a user measures blood pressure with a sphygmomanometer 100 in a normal blood pressure measurement mode. In this example, when the measurement switch 52A is continuously pressed for, for example, 3 seconds or more in the power-off state, the power is turned on and the normal blood pressure measurement mode is set by default.

As shown in FIG. 4A, it is assumed that the user 80 wearing the sphygmomanometer 100 on the left wrist 90 is in a sitting posture.

In this state, as shown in step S1 of FIG. 5, when the user presses down the measurement switch 52A provided on the main body 10 and inputs a blood pressure measurement instruction, the CPU 110 initializes the pressure sensor 31 (step S2). Specifically, the CPU 110 initializes the processing memory area, turns off (stops) the pump 32, and adjusts the pressure sensor 31 to 0 mmHg (atmospheric pressure is set to 0 mmHg) with the valve 33 open. )I do.

Next, the CPU 110 closes the valve 33 via the valve drive circuit 330 (step S3), and then turns on (starts) the pump 32 via the pump drive circuit 320 to form the cuff 20 (fluid bag 22). Pressurization is started (step S4). At this time, the CPU 110 is the pressure inside the fluid bag 22 as shown in FIG. 7A based on the output of the pressure sensor 31 while supplying air from the pump 32 to the fluid bag 22 through the air pipe 39. Cuff pressure Controls the pressurization speed of the PC.

Next, in step S5 of FIG. 5, the CPU 110 acts as a blood pressure calculation unit, and the pulse wave signal SM (variable component due to the pulse wave included in the output of the pressure sensor 31) acquired at this time (FIG. 7 (FIG. 7). Based on (B)), the calculation of the blood pressure value (maximum blood pressure (systolic blood pressure) and diastolic blood pressure (diastolic blood pressure)) is attempted using the sitting algorithm stored in the memory 51.

At this point, if the blood pressure value cannot be calculated yet due to lack of data (No in step S6), the cuff pressure PC reaches the upper limit pressure (for safety, for example, 300 mmHg is predetermined). Unless otherwise specified, the processes of steps S4 to S6 are repeated.

Here, the CPU 110 calculates the blood pressure value as follows. That is, with respect to the sequence of pulse wave amplitudes (peak to peak) formed by the pulse wave signal SM shown in FIG. 7 (B) obtained from the cuff pressure PC when the cuff 20 is in the pressurizing process, FIG. 7 The envelope ENV as shown in (C) is set. Along with this, it sets the maximum value AmpMax envelope ENV, predetermined ratio alpha _dia for loci, two threshold level THD1, Ths1 of alpha _sys. THD1 is a threshold level for diastolic blood pressure and is _{set as THD1 = α dia} × AmpMax. Further, Ths1 is the threshold level for the systolic blood pressure, is set as THS1 = α _sys × AmpMax. As an example, α _dia = 0.75 and α _sys = 0.4 (that is, THD1 = 0.75 × AmpMax and THS1 = 0.4 × AmpMax are set. ). Then, as shown in FIG. 7 (A), the cuff pressure PCs at the time when the envelope ENV crossed those threshold levels THD1 and THS1 are the diastolic blood pressure (diastolic blood pressure) BPdia1 and the systolic blood pressure (systolic blood pressure), respectively. Calculated as BPsys1.

When the blood pressure value can be calculated in this way (Yes in step S6), the CPU 110 turns off the pump 32 (step S7), opens the valve 33 (step S8), and enters the cuff 20 (fluid bag 22). Controls the exhaust of air.

After that, the CPU 110 displays the calculated blood pressure value on the display 50 (step S9), and controls the storage of the blood pressure value in the memory 51.

FIG. 6 shows an operation flow when the user performs blood pressure measurement in the nocturnal blood pressure measurement mode by the sphygmomanometer 100. At the start of this flow, the sphygmomanometer 100 is assumed to be in the normal blood pressure measurement mode.

As shown in step S11 of FIG. 6, when the user presses down the nighttime measurement switch 52B provided on the main body 10, the sphygmomanometer 100 shifts from the normal blood pressure measurement mode to the nighttime blood pressure measurement mode. In this example, in the nighttime blood pressure measurement mode, it is assumed that a schedule for measuring once every two hours is set from the time when the nighttime measurement switch 52B is pressed until, for example, 7:00 am. The schedule is not limited to this, and a schedule for measuring at a fixed time such as 7:00 am, 1:00 am, 2:00 pm, and 3:00 am may be set after the nighttime measurement switch 52B is pressed. ..

With the transition to the nocturnal blood pressure measurement mode, as shown in step S12, the CPU 110 acts as a first switching unit to change the algorithm for calculating blood pressure by the oscillometric method from the algorithm for sitting position to the algorithm for supine position. Switch and set.

Specifically, as shown in FIG. 8, the threshold level for diastolic blood pressure is set by switching from THD1 to THD2, and the threshold level for systolic blood pressure is set by switching from THS1 to THS2. Here, THD2 = 0.6 × AmpMax is set, and THS2 = 0.5 × AmpMax is set. _{This changed the ratio α dia} of the envelope ENV to the maximum value AmpMax from 0.75 for the sitting position to 0.6 for the supine position, and changed the ratio α _sys of the envelope ENV to the maximum value AmpMax for the sitting position. It is equivalent to changing from 0.4 of 0.4 to 0.5 for supine position. These changes in the ratios α _dia and α _sys are for eliminating the deviation of the blood pressure measurement value in the supine position (FIG. 4B) from the blood pressure measurement value in the sitting position (FIG. 4A).

It is desirable that the memory 51 includes a flag indicating the currently set algorithm among the sitting algorithm and the supine algorithm. In that case, the CPU 110 can easily recognize the currently set algorithm by referring to the flag.

Next, as shown in step S13 of FIG. 6, the CPU 110 determines whether or not the measurement time is determined by the schedule (in the nighttime blood pressure measurement mode). If it is not the measurement time specified in the schedule (No in step S13), unless the measurement switch 52A is pressed down, the measurement time is waited to reach the measurement time specified in the schedule (No in step S25).

At the measurement time determined in the above schedule (Yes in step S13), the CPU 110 starts blood pressure measurement in the same manner as in steps S2 to S4 of FIG. 5, as shown in steps S14 to S16 of FIG. That is, the CPU 110 first initializes the pressure sensor 31 (step S14).

Next, the CPU 110 closes the valve 33 via the valve drive circuit 330 (step S15), and then turns on (starts) the pump 32 via the pump drive circuit 320 to form the cuff 20 (fluid bag 22). Pressurization is started (step S16). At this time, the CPU 110 controls the pressurizing speed of the cuff pressure PC in the same manner as shown in FIG. 7A.

Next, in step S17 of FIG. 6, the CPU 110 acts as a blood pressure calculation unit, and the pulse wave signal SM (variable component due to the pulse wave included in the output of the pressure sensor 31) acquired at this time (FIG. 7 (FIG. 7). Based on (similar to that shown in B), the blood pressure values (maximum blood pressure (systolic blood pressure) and diastolic blood pressure (diastolic)) are used using the currently set algorithm (at this point, the algorithm for the supine position). Try to calculate blood pressure)).

At this point, if the blood pressure value cannot be calculated yet due to lack of data (No in step S18), the cuff pressure PC reaches the upper limit pressure (for safety, for example, 300 mmHg is predetermined). Unless otherwise specified, the processes of steps S16 to S18 are repeated.

Here, the CPU 110 calculates the blood pressure value as follows. That is, the envelope ENV as shown in FIG. 8 with respect to the sequence of pulse wave amplitudes (peak to peak) formed by the pulse wave signal SM obtained from the cuff pressure PC when the cuff 20 is in the pressurizing process. (Similar to that shown in FIG. 7C) is set. Then, the cuff pressure PC at the time when the envelope ENV crosses the supine position threshold THD2 (= 0.6 × AmpMax) and THS2 (= 0.5 × AmpMax), which are currently set, is set to the diastolic blood pressure (= 0.6 × AmpMax). It is calculated as diastolic blood pressure) BPdia2 and systolic blood pressure (systolic blood pressure) BPsys2.

In nocturnal blood pressure measurement mode, the user is usually expected to be in the supine position. Therefore, by using the algorithm for the supine position, the blood pressure values (maximum blood pressure and diastolic blood pressure) can be calculated stably and accurately.

When the blood pressure value can be calculated in this way (Yes in step S18), the CPU 110 turns off the pump 32 (step S19), opens the valve 33 (step S20), and enters the cuff 20 (fluid bag 22). Controls the exhaust of air.

After that, the CPU 110 displays the calculated blood pressure value on the display 50 (step S21), and controls the storage of the blood pressure value in the memory 51.

When one blood pressure measurement defined in the above schedule is completed in this way, in step S22, the CPU 110 determines whether or not all the blood pressure measurements defined in the above schedule are completed. Here, as long as the blood pressure measurement is still scheduled according to the above schedule (“incomplete” in step S22), the algorithm currently set is the algorithm for the supine position (No in step S23), so step S13 as it is. Return to. Then, it waits for the next measurement time determined in the above schedule (No in step S13, No in step S25).

When the next measurement time determined in the above schedule is reached (Yes in step S13), the CPU 110 repeats the processes of steps S14 to S21. Further, in step S22, the CPU 110 determines whether or not all the blood pressure measurements defined in the above schedule have been completed, and as long as the blood pressure measurement is still scheduled according to the above schedule (“incomplete” in step S22). The process returns to step S13 as it is (No in step S23). Then, it waits for the next measurement time determined in the above schedule (No in step S13, No in step S25).

By the way, even while the sphygmomanometer 100 is in the nighttime blood pressure measurement mode, the user may instruct the blood pressure measurement by interruption by pressing the measurement switch 52A separately from the predetermined schedule (the above-mentioned predetermined schedule). Yes) in step S25. At this time, the user is expected to be in the sitting position rather than in the supine position. Therefore, the CPU 110 functions as a second switching unit to switch the algorithm for calculating blood pressure by the oscillometric method from the algorithm for the supine position to the algorithm for the sitting position (step S26).

Subsequently, as shown in steps S14 to S16, the CPU 110 starts blood pressure measurement in response to the interrupted blood pressure measurement instruction. That is, the CPU 110 first initializes the pressure sensor 31 (step S14).

Next, the CPU 110 closes the valve 33 via the valve drive circuit 330 (step S15), and then turns on (starts) the pump 32 via the pump drive circuit 320 to form the cuff 20 (fluid bag 22). Pressurization is started (step S16). At this time, the CPU 110 controls the pressurizing speed of the cuff pressure PC in the same manner as shown in FIG. 7A.

Next, in step S17 of FIG. 6, the CPU 110 acts as a blood pressure calculation unit, and the pulse wave signal SM (variable component due to the pulse wave included in the output of the pressure sensor 31) acquired at this time (FIG. 7 (FIG. 7). Based on (similar to that shown in B), the blood pressure values (maximum blood pressure (systolic blood pressure) and diastolic blood pressure (diastolic blood pressure)) are used using the currently set algorithm (at this point, the algorithm for sitting position). )) Try to calculate.

At this point, if the blood pressure value cannot be calculated yet due to lack of data (No in step S18), the cuff pressure PC reaches the upper limit pressure (for safety, for example, 300 mmHg is predetermined). Unless otherwise specified, the processes of steps S16 to S18 are repeated.

Here, the CPU 110 calculates the blood pressure value as follows. That is, the envelope ENV as shown in FIG. 8 with respect to the sequence of pulse wave amplitudes (peak to peak) formed by the pulse wave signal SM obtained from the cuff pressure PC when the cuff 20 is in the pressurizing process. To set. Then, the cuff pressure PC at the time when the envelope ENV crosses the currently set threshold threshold THD1 (= 0.75 × AmpMax) and THS1 (= 0.4 × AmpMax) for sitting position is subjected to diastole (diastole), respectively. It is calculated as BPdia1 (diastolic blood pressure) and BPsys1 for systolic blood pressure (systolic blood pressure).

When the blood pressure measurement is instructed by pressing down the measurement switch 52A (Yes in step S25), the user is expected to be in the sitting position rather than in the supine position. Therefore, by using the sitting algorithm, the blood pressure values (maximum blood pressure and diastolic blood pressure) can be calculated stably and accurately.

When the blood pressure value can be calculated in this way (Yes in step S18), the CPU 110 turns off the pump 32 (step S19), opens the valve 33 (step S20), and enters the cuff 20 (fluid bag 22). Controls the exhaust of air.

After that, the CPU 110 displays the calculated blood pressure value on the display 50 (step S21), and controls the storage of the blood pressure value in the memory 51.

When the blood pressure measurement according to the blood pressure measurement instruction of the interrupt is completed in this way, in step S22, the CPU 110 determines whether or not all the blood pressure measurements defined in the above schedule are completed. Here, it is assumed that the blood pressure measurement is still scheduled according to the above schedule (“incomplete” in step S22). Since the currently set algorithm is a sitting algorithm (Yes in step S23), the CPU 110 acts as a third switching unit, and the algorithm for calculating blood pressure by the oscillometric method is changed from the sitting algorithm to the above. The algorithm is switched to the supine position algorithm and set (step S24). After that, the process returns to step S13. Then, it waits for the next measurement time determined in the above schedule (No in step S13, No in step S25).

When the next measurement time determined in the above schedule is reached (Yes in step S13), the CPU 110 repeats the processes of steps S14 to S21. In this way, even after the blood pressure measurement according to the interrupted blood pressure measurement instruction is completed, the blood pressure measurement is automatically started according to the above schedule. At that time, in step S18, the CPU 110 calculates the diastolic blood pressure (diastolic blood pressure) BPdia2 and the systolic blood pressure (systolic blood pressure) BPsys2 using the supine position algorithm as the blood pressure calculation unit.

In the nocturnal blood pressure measurement mode, as mentioned above, the user is usually expected to be in the supine position. Therefore, after the blood pressure measurement according to the above-mentioned interrupted blood pressure measurement instruction is completed, the blood pressure value (maximum blood pressure and diastolic blood pressure) can be calculated stably and accurately by using the supine position algorithm.

In this way, when all the blood pressure measurements defined in the above schedule are completed (“finished” in step S22), the CPU 110 acts as a fourth switching unit and supines the algorithm for calculating blood pressure by the oscillometric method. The algorithm for sitting is switched to the algorithm for sitting position (step S27). Then, the nighttime blood pressure measurement mode is terminated.

As a result, after the end of the nocturnal blood pressure measurement mode, for example, when the normal blood pressure measurement mode is started by default, in step S5 of FIG. 5, the CPU 110 serves as a blood pressure calculation unit to calculate the blood pressure by the oscillometric method. The blood pressure value can be calculated using the sitting position algorithm. Therefore, the blood pressure calculation in the normal blood pressure measurement mode can be correctly executed.

As is clear from the above, according to this sphygmomanometer 100, the blood pressure value is stabilized when the blood pressure is measured according to the interrupted blood pressure measurement instruction in the nighttime blood pressure measurement mode, in addition to the predetermined schedule. Can be calculated accurately.

Further, since the sphygmomanometer 100 is a type that presses the wrist as the measurement site (the left wrist 90 is used in the above example, but the right wrist may also be used), the blood pressure monitor 100 is compared with the type that presses the upper arm. It is expected that the degree of disturbing the sleep of the user (subject) is small (Imai et al., “Development and evaluation of a home nocturnal blood pressure monitoring system using a wrist-cuff device”, Blood Pressure Monitoring 2018, 23, P318. -326). Therefore, this sphygmomanometer 100 is suitable for nighttime blood pressure measurement.

Further, since the sphygmomanometer 100 is integrally and compactly configured as a wrist-type sphygmomanometer, it is convenient for the user to handle.

(Modification example)
In the above-described embodiment, in the operation flow of the nighttime blood pressure measurement mode of the sphygmomanometer 100 (FIG. 6), the measurement switch 52A is pressed down to determine whether or not a blood pressure measurement instruction has been given by interruption (step S25). The CPU 110 functions as a second switching unit, and includes a process (step S26) of switching and setting the blood pressure calculation algorithm by the oscillometric method from the recumbent position algorithm to the sitting position algorithm. However, the present invention is not limited to this, and those processes (steps S25 and S26) may be omitted. In that case, a process for determining whether or not the currently set algorithm is a sitting algorithm (step S23) and the CPU 110 act as a third switching unit to provide an algorithm for calculating blood pressure by the oscillometric method. The process of switching from the sitting algorithm to the supine algorithm and setting the algorithm (step S24) can be omitted at the same time. As a result, the operation flow of the nighttime blood pressure measurement mode (FIG. 6) can be simplified.

Further, in the above-described embodiment, in the operation flow (FIG. 6) of the nocturnal blood pressure measurement mode of the sphygmomanometer 100, after all the blood pressure measurements defined in the schedule are completed (“end” in step S22), the CPU 110 is the first. 4 It is assumed that it functions as a switching unit and includes a process (step S27) of switching and setting the algorithm for calculating blood pressure by the oscillometric method from the algorithm for the supine position to the algorithm for the sitting position. However, the present invention is not limited to this, and the process (step S27) may be omitted. As a result, the operation flow of the nighttime blood pressure measurement mode (FIG. 6) can be simplified. In that case, the user shall temporarily turn off the power of the sphygmomanometer 100 after the nighttime blood pressure measurement is completed (in this example, when the measurement switch 52A is continuously pressed for, for example, 3 seconds or more while the power is on. The power turns off.) When the user wants to measure the blood pressure at night again, the power of the sphygmomanometer 100 is turned on (as described above, when the measurement switch 52A is continuously pressed for, for example, 3 seconds or more in the power off state, the power is turned on. ), By default, the normal blood pressure measurement mode (algorithm for sitting position) may be set, and then the nighttime measurement switch 52B may be pressed down to set the nighttime blood pressure measurement mode (algorithm for lying down position).

Further, in the above-described embodiment, the blood pressure is calculated in the process of pressurizing the cuff 20 (fluid bag 22), but the present invention is not limited to this. Blood pressure may be calculated in the process of depressurizing the cuff 20.

Further, in the above-described embodiment, the measurement switch 52A and the nighttime measurement switch 52B provided on the main body 10 are provided as the measurement instruction input unit and the mode operation unit, respectively, but the present invention is not limited thereto. The measurement instruction input unit and the mode operation unit may be configured by, for example, a communication unit that receives an instruction from a smartphone or the like existing outside the sphygmomanometer 100 via wireless communication.

Further, in the above-described embodiment, the main body 10 is provided integrally with the cuff 20, but the present invention is not limited to this. The main body 10 may be configured as a separate body from the cuff 20 and may be connected to the cuff 20 (fluid bag 22) so that fluid can flow through a flexible air tube.

The above-mentioned blood pressure calculation method (particularly, the operation flow of FIG. 6) is used as software (computer program) for non-transitory data such as a CD (compact disc), a DVD (digital universal disc), and a flash memory. May be recorded on a storable recording medium. By installing the software recorded on such a recording medium on a substantial computer device such as a personal computer, a PDA (Personal Digital Assistance), or a smartphone, the above-mentioned blood pressure calculation method can be applied to those computer devices. Can be executed.

The above embodiment is an example, and various modifications can be made without departing from the scope of the present invention. The plurality of embodiments described above can be established independently, but combinations of the embodiments are also possible. Further, although various features in different embodiments can be established independently, it is also possible to combine features in different embodiments.

10 Main unit 20 Blood pressure measurement cuff 50 Display 51 Memory 52 Operation unit 52A Measurement switch 52B Night measurement switch 110 CPU

Claims (7)

A sphygmomanometer that measures blood pressure by the oscillometric method by temporarily pressing the wrist as the measurement site with a blood pressure measurement cuff.
A measurement instruction input unit for inputting blood pressure measurement instructions,
A mode between a normal blood pressure measurement mode in which blood pressure is measured according to a blood pressure measurement instruction input by the measurement instruction input unit and a nighttime blood pressure measurement mode in which blood pressure measurement is automatically started according to a predetermined schedule. Mode operation unit for inputting instructions to switch between
As an algorithm for calculating blood pressure by the oscillometric method, an algorithm storage unit that stores an algorithm for sitting and an algorithm for supine position,
When the normal blood pressure measurement mode is switched to the nocturnal blood pressure measurement mode by the mode operation unit, the algorithm for calculating the blood pressure by the oscillometric method is set by switching from the algorithm for the sitting position to the algorithm for the lying position. Switching part and
When the blood pressure measuring cuff is in the pressurizing process or the depressurizing process, the blood pressure value is calculated based on the pressure of the blood pressure measuring cuff using the algorithm currently set for calculating the blood pressure by the oscillometric method. A sphygmomanometer characterized by having a blood pressure calculation unit for calculating. In the sphygmomanometer according to claim 1.
In the nighttime blood pressure measurement mode, when a blood pressure measurement instruction is input by an interrupt by the measurement instruction input unit in addition to the predetermined schedule, the sphygmomanometer is used to measure the blood pressure according to the interrupted blood pressure measurement instruction. A sphygmomanometer including a second switching unit for switching and setting an algorithm for calculating blood pressure by the metric method from the algorithm for the supine position to the algorithm for the sitting position. In the sphygmomanometer according to claim 2.
When the blood pressure measurement according to the blood pressure measurement instruction of the interruption is completed, as long as the blood pressure measurement is still scheduled according to the schedule, the algorithm for calculating the blood pressure by the oscillometric method is changed from the algorithm for the sitting position to the algorithm for the supine position. A sphygmomanometer characterized by having a third switching unit for switching and setting an algorithm. In the sphygmomanometer according to any one of claims 1 to 3.
When all the blood pressure measurements specified in the above schedule are completed, a fourth switching unit is provided to switch the algorithm for calculating blood pressure by the oscillometric method from the algorithm for the supine position to the algorithm for the sitting position. A blood pressure monitor featuring. In the sphygmomanometer according to any one of claims 1 to 4.
Equipped with a main body provided integrally with the above blood pressure measurement cuff,
The measurement instruction input unit and the mode operation unit include switches provided on the outer surface of the main body, respectively.
The main body is a sphygmomanometer including the algorithm storage unit, each switching unit, a pressure control unit for controlling the pressure of the blood pressure measurement cuff, and the blood pressure calculation unit. It is a blood pressure calculation method for a sphygmomanometer that temporarily presses the wrist as a measurement site with a blood pressure measurement cuff and measures the blood pressure by the oscillometric method.
The above blood pressure monitor
A measurement instruction input unit for inputting blood pressure measurement instructions,
A mode between a normal blood pressure measurement mode in which blood pressure is measured according to a blood pressure measurement instruction input by the measurement instruction input unit and a nighttime blood pressure measurement mode in which blood pressure measurement is automatically started according to a predetermined schedule. Mode operation unit for inputting instructions to switch between
As an algorithm for calculating blood pressure by the oscillometric method, an algorithm storage unit that stores an algorithm for sitting and an algorithm for supine position,
With
The above blood pressure calculation method is
When the normal blood pressure measurement mode is switched to the nocturnal blood pressure measurement mode by the above mode operation unit, the algorithm for calculating blood pressure by the oscillometric method is set by switching from the algorithm for sitting position to the algorithm for lying position.
When the blood pressure measuring cuff is in the pressurizing process or the depressurizing process, the blood pressure value is calculated based on the pressure of the blood pressure measuring cuff using the algorithm currently set for calculating the blood pressure by the oscillometric method. A blood pressure calculation method characterized by calculating. A program for causing a computer to execute the blood pressure calculation method according to claim 6.

Images