BLOOD PRESSURE MEASUREMENT DEVICE AND BLOOD PRESSURE MEASUREMENT METHOD

A blood pressure measurement device according to an aspect includes a blood pressure measurement unit that measures a blood pressure of a user, a setting unit that sets a measurement scheduled time for a time a predetermined time period before a wake-up scheduled time of the user, and a measurement control unit that causes the blood pressure measurement unit to measure the blood pressure of the user in accordance with the set measurement scheduled time.

TECHNICAL FIELD

Aspects of the present invention relate to technology for measuring blood pressure of a user during sleep.

BACKGROUND ART

In general, blood pressures of human beings are lower during sleep than during wakefulness. However, high values of blood pressure may persist throughout the night without decreasing during sleep. Such a phenomenon is referred to as nocturnal hypertension. There are several types of nocturnal hypertension. In other types of nocturnal hypertension, transient blood pressure variations occur at timing when sleep deepens or immediately before wake-up. The nocturnal hypertension may be caused by a certain disease, and it is important to determine whether the user has nocturnal hypertension. This requires measuring the blood pressure of the user during sleep. For measurement of the blood pressure of the user during sleep, an electronic blood pressure monitor is known that is configured to measure the blood pressure of the user at a preset time (e.g., 2 a.m.) (see, e.g., Patent Document 1).

Meanwhile, for management of the blood pressure, it is important to know a blood pressure change before and after wake-up. For example, immediately before wake-up of the user, a transient blood pressure variation may occur in which the blood pressure surges suddenly and then decreases.

To detect such a blood pressure variation, the blood pressure needs to be measured before and after wake-up.

CITATION LIST

Patent Literature

Patent Document 1: JP 2001-70260 A

SUMMARY OF INVENTION

Technical Problem

In an electronic blood pressure monitor such as that disclosed in Patent Document 1, measurement time is generally set for a time when the user is assumed to be reliably asleep. This precludes blood pressure measurement before wake-up, and prevents detection of blood pressure changes before and after wake-up.

In view of the above-described circumstances, an object of the present invention is to provide a blood pressure measurement device and a blood pressure measurement method that enable observation of blood pressure changes before and after wake-up.

Solution to Problem

The present invention adopts the following configurations to solve the above-described problems.

In a first aspect of the present invention, a blood pressure measurement device includes a blood pressure measurement unit configured to measure a blood pressure of a user, a setting unit configured to set a measurement scheduled time for a time a predetermined time period before a wake-up scheduled time of the user, and a measurement control unit configured to cause the blood pressure measurement unit to measure the blood pressure of the user in accordance with the set measurement scheduled time.

According to the above-described configuration, the blood pressure is measured at the time the predetermined time period before the wake-up scheduled time of the user. This allows the blood pressure of the user to be measured immediately before wake-up. As a result, blood pressure changes before and after wake-up can be observed.

In a second aspect of the present invention, the setting unit sets the measurement scheduled time by using, as the wake-up scheduled time, an earliest alarm time of a plurality of preset alarm times when an alarm is output.

According to the above-described configuration, blood pressure measurement can be more reliably performed before the user wakes up.

In a third aspect of the present invention, the setting unit sets the measurement scheduled time by using a wake-up time of the user for a preceding day as the wake-up scheduled time.

According to the above-described configuration, blood pressure measurement can be more reliably performed before the user wakes up.

In a fourth aspect of the invention, the blood pressure measurement device further includes a sleep detection unit configured to detect a depth of sleep of the user, and the measurement control unit causes the blood pressure measurement unit to measure the blood pressure of the user when the sleep detection unit detects that the sleep is shallow within a time range ending at the set measurement scheduled time, and causes the blood pressure measurement unit to measure the blood pressure of the user at the set measurement scheduled time in a case where the sleep detection unit does not detect that the sleep is shallow within the time range.

According to the above-described configuration, blood pressure measurement can be performed at timing before wake-up when the blood pressure is predicted to be high. As a result, blood pressure changes before and after wake-up can be effectively observed.

In a fifth aspect of the present invention, the blood pressure measurement device further includes a heart rate measurement unit configured to measure a heart rate of the user, and the measurement control unit causes the blood pressure measurement unit to measure the blood pressure of the user when a measurement value of the heart rate exceeds a threshold that is preset, within a time range ending at the set measurement scheduled time, and causes the blood pressure measurement unit to measure the blood pressure of the user at the measurement scheduled time in a case where the measurement value of the heart rate does not exceed the threshold within the time range.

According to the above-described configuration, blood pressure measurement can be performed at timing before wake-up when the blood pressure is predicted to be high. As a result, blood pressure changes before and after wake-up can be effectively observed.

In a sixth aspect of the present invention, the blood pressure measurement device further includes a determination unit configured to determine the predetermined time period based on measurement results obtained by measuring the blood pressure of the user before the measurement scheduled time for a plurality of days.

According to the above-described configuration, blood pressure measurement can be performed at timing before wake-up when the blood pressure is likely to be high. As a result, blood pressure changes before and after wake-up can be effectively observed.

In a seventh aspect of the present invention, a blood pressure measurement method performed by a blood pressure measurement device including a blood pressure measurement unit configured to measure a blood pressure of a user includes the steps of setting a measurement scheduled time for a time a predetermined time period before a wake-up scheduled time of the user, and causing the blood pressure measurement unit to measure the blood pressure of the user in accordance with the set measurement scheduled time.

The seventh aspect can produce effects similar to those of the first aspect.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a blood pressure measurement device and a blood pressure measurement method can be provided that allow for observation of blood pressure changes before and after wake-up.

DESCRIPTION OF EMBODIMENTS

Overview

First, an overview of the present invention will be described with reference toFIG. 1.

FIG. 1schematically illustrates a health management system10according to an embodiment. As illustrated inFIG. 1, health management system10includes an electronic blood pressure monitor11, a smartphone12, a server13, and a physician terminal14. The electronic blood pressure monitor11and the smartphone12are associated with a user who is a patient, and the physician terminal14is associated with the physician. The blood pressure monitor11communicates directly with the smartphone12. The smartphone12, the server13, and the physician terminal14communicate with one another via a network NW such as the Internet.

The blood pressure monitor11is configured to measure the blood pressure of the user. The blood pressure monitor11is, for example, an oscillometric blood pressure monitor. As an example, measurement is scheduled to take place three times each day, before wake-up, after wake-up, and before bed. Specifically, the blood pressure monitor11performs manual measurement at 11 p.m. The user then goes to bed with the blood pressure monitor11attached. The blood pressure monitor11performs automatic measurement before wake-up of the user. Furthermore, the blood pressure monitor11performs manual measurement after wake-up. In this regard, manual measurement refers to measurement performed using, as a trigger, operation of the user such as button depression, and automatic measurement refers to measurement performed with no operation of the user. The blood pressure monitor11transmits measurement data indicative of a measurement result to the smartphone12each time measurement is performed. The blood pressure monitor11corresponds to a blood pressure measurement device of the present invention.

The blood pressure monitor11performs measurement before wake-up of the user, as described below. The blood pressure monitor11sets a measurement scheduled time for a time a predetermined time period before a wake-up scheduled time of the user, and measures the blood pressure of the user at the measurement scheduled time. In one example, as the wake-up scheduled time, an output time for a wake-up alarm set in the smartphone12is utilized. In this case, the blood pressure monitor11receives, from the smartphone12, alarm data indicating an alarm time, corresponding to the time when the wake-up alarm is output, and considers, as a wake-up scheduled time, the alarm time indicated by the received alarm data. For example, in a case where the alarm time is 6:00 a.m. and the predetermined time period is 20 minutes, the measurement scheduled time is set for 5:40 a.m.

The smartphone12receives measurement data from the blood pressure monitor11. The smartphone12includes an application that manages data related to a user (hereinafter referred to as user data) and including measurement results obtained by the blood pressure monitor11. The application graphically displays the measurement results and displays the results of analysis of the measurement results. Furthermore, the smartphone12transmits the user data to the server13.

The server13receives the user data from the smartphone12and manages the user data received. For example, the server13transmits the user data to the physician terminal14in response to a request from the physician terminal14.

The physician terminal14is a computer such as a personal computer (PC). When the physician examines the user, the physician terminal14accesses the server13to obtain the user data. Specifically, the physician terminal14transmits a request to the server13, and receives the user data from the server13. The physician terminal14displays measurement results obtained by the blood pressure monitor11and included in the received user data. In this way, the measurement results obtained through measurement at the home of the user are utilized by the physician to examine the user.

In the health management system10having the configuration described above, the blood pressure monitor11sets the measurement scheduled time for the time the predetermined time period before the wake-up scheduled time of the user, and measures the blood pressure of the user at the measurement scheduled time. This allows the blood pressure measurement to be performed immediately before wake-up of the user. As a result, blood pressure variations before and after wake-up can be detected. For example, it is possible to observe whether a transient blood pressure variation has occurred immediately before wake-up.

Now, the blood pressure monitor11will be described in detail.

Configuration Example

Hardware Configuration

An example of the hardware configuration of the blood pressure monitor11will be described with reference toFIGS. 2 and 3.FIG. 2is a block diagram that schematically illustrates a hardware configuration of the blood pressure monitor11, andFIG. 3is a perspective view schematically illustrating the appearance of the blood pressure monitor11.

As illustrated inFIG. 2, the blood pressure monitor11includes a control unit21, a storage device22, a display device23, an input device24, a speaker25, a communication interface26, and a blood pressure measurement unit27.

In one example, the blood pressure monitor11uses a dry battery as a power source.

The control unit21includes a Central Processing Unit (CPU)211, a Random Access Memory (RAM)212, a program memory213, and the like and controls each of the components. The CPU211is an example of a hardware processor. The RAM212is a volatile memory such as a Static RAM (SRAM) is used as a working memory for the CPU211. The program memory213stores programs and setting data necessary to execute the programs. As the program memory213, for example, a Read-Only Memory (ROM) is used. Note that the program memory213may be part of the storage device22.

The storage device22is a non-volatile memory, for example, flash memory, and stores data such as measurement results. A storage medium included in the storage device22is a medium that stores information such as recorded programs by an electrical, magnetic, optical, mechanical, or chemical action such that a computer, a machine, and the like can read the information such as the program.

The display device23displays information such as measurement results. The display device23is, for example, a segmented liquid crystal display device. The display device23may be a liquid crystal display device based on a dot matrix or an Organic Light Emitting Diode (OLED) display.

The input device24allows the user to input instructions to the blood pressure monitor11. The input device24includes a plurality of push buttons, such as a start button for starting blood pressure measurement. Note that the input device24may be a touch panel provided on a screen of the display device23.

The speaker25emits sound based on acoustic signals from the control unit21. For example, speaker25is used to prompt the user to measure the blood pressure.

The communication interface26is an interface for communicating with an external device. The communication interface26includes, for example, a short-range wireless module such as a Bluetooth (trademark) module or a Bluetooth Low Energy (BLE) module and wirelessly communicates with the smartphone12(FIG. 1). The communication interface26may include, instead of the short-range wireless module, other wireless module such as a wireless

Local Area Network (LAN) module. Additionally, the communication interface26may include a terminal such as a micro Universal Serial Bus (USB) connector and may communicate with an external device via a cable such as a USB cable.

The blood pressure measurement unit27measures the blood pressure. The blood pressure measurement unit27includes a pressing cuff271, a pump272, a pump drive circuit273, a valve274, a valve drive circuit275, a pressure sensor276, an oscillation circuit277, and tubes278,279. In the example illustrated inFIG. 3, the pressing cuff271is separate from a body28. In a case of blood pressure measurement, the pressing cuff271is attached to the upper arm of the user. The body28houses the control unit21, the storage device22, the display device23, the input device24, the speaker25, the communication interface26, the pump272, the pump driver circuit273, the valve274, the valve drive circuit275, the pressure sensor276, and the oscillation circuit277.

The pump272and the valve274are connected to the pressing cuff271via the tube279. The pressure sensor276is connected to the pressing cuff271via the tube278. Note that the tubes278,279may be a common single pipe. The pump272is, for example, a piezoelectric pump and feeds air to the pressing cuff271through the tube278to increase pressure inside the pressing cuff271. The pump drive circuit273is controlled by the control unit21and drives the pump272. The valve drive circuit275is controlled by the control unit21and drives the valve274. With the valve274open, the pressing cuff271is in communication with the atmosphere. The valve274includes the function of a check valve and prevents air from flowing into the pressing cuff271through the valve274.

The pressure sensor276is, for example, a piezoresistive pressure sensor, detects pressure inside the pressing cuff271(hereinafter, also referred to as cuff pressure), and outputs an electrical signal representing the cuff pressure. The cuff pressure is, for example, pressure based on atmospheric pressure as a reference. The oscillation circuit277oscillates based on an electrical signal from the pressure sensor276and outputs, to the control unit21, a frequency signal having a frequency in accordance with the electrical signal. An output of the pressure sensor276is used to control the pressure of the pressing cuff271and to calculate the blood pressure value using the oscillometric method.

Note that, with regard to the specific hardware configuration of the blood pressure monitor11, omission, replacement, and addition of components can be made as appropriate according to the embodiment. For example, the control unit21may include a plurality of hardware processors. The blood pressure monitor11may be a wearable blood pressure monitor, such as a wristwatch type blood pressure monitor.

Software Configuration

With reference toFIG. 4, an example of a software configuration of the blood pressure monitor11will be described.FIG. 4is a block diagram illustrating an example of the software configuration of the blood pressure monitor11. As illustrated inFIG. 4, the blood pressure monitor11includes an input unit41, a display control unit42, a communication control unit43, a measurement scheduled time setting unit44, a measurement control unit45, a measurement notification unit46, and a measurement result storage unit47. The input unit41, the display control unit42, the communication control unit43, the measurement scheduled time setting unit44, the measurement control unit45, and the measurement notification unit46execute the following processes by the control unit21of the blood pressure monitor11executing programs stored in the program memory213. When the control unit21executes a program, the control unit21unfolds the program in the RAM212. Then, the control unit21causes the CPU211to interpret and execute the program unfolded in the RAM212to control each of the components. The measurement result storage unit47is provided in the storage device22.

The input unit41receives an input from the user. The input unit41receives, from the input device24, an operation signal corresponding to an operation performed by the user on the input device24and determines contents of an instruction input by the user based on the operation signal. The instruction includes, for example, an instruction to start blood pressure measurement, an instruction to suspend the blood pressure measurement, an instruction to display a history of measurement results, and an instruction to transmit measurement data to the smartphone12. For example, in a case where the user instructs the start of blood pressure measurement, the input unit41provides a measurement start instruction signal to the measurement control unit45. In a case where the user instructs the display of the history of measurement results, the input unit41provides a history display signal to the display control unit42.

The communication control unit43controls the communication interface26. The communication control unit43receives measurement results from the measurement control unit45via the measurement result storage unit47after the blood pressure measurement, and transmits measurement data indicating the measurement results, to the smartphone12(FIG. 1) via the communication interface26. The communication control unit43receives alarm data indicative of the alarm time from the smartphone12via the communication interface26, and provides the received alarm data to the measurement scheduled time setting unit44and the measurement notification unit46.

The measurement scheduled time setting unit44sets the measurement scheduled time based on the wake-up scheduled time of the user. The measurement scheduled time is a time at which blood pressure measurement is scheduled to be performed. In the present embodiment, the measurement scheduled time setting unit44sets the measurement scheduled time for the time a predetermined time period before the wake-up scheduled time of the user. The predetermined time period may be, for example, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 1 hour, or the like.

In one example, the measurement scheduled time setting unit44receives the alarm data from the communication control unit43, and uses an alarm time indicated by the received alarm data as a wake-up scheduled time to set the measurement scheduled time. Specifically, the measurement scheduled time setting unit44sets the measurement scheduled time for the time the predetermined time period before the alarm time. The measurement scheduled time setting unit44provides the measurement control unit45with measurement scheduled time information indicating the set measurement scheduled time.

The wake-up alarm refers to, for example, an alarm that is estimated to be set for a user to wake up. For example, an alarm that is within a specified time range (e.g., a time range from 5 a.m. to 9 a.m.) is considered as a wake-up alarm. In a case where a plurality of alarm times for the wake-up alarm are set in the smartphone12, the earliest alarm time of these alarm times is used as the wake-up scheduled time. For example, in a case where alarm times of 6:00 a.m. and 6:30 a.m. are set, the measurement scheduled time setting unit44sets the measurement scheduled time using 6:00 a.m. as the wake-up scheduled time.

Note that the blood pressure monitor11may acquire alarm data from any other device including an alarm function and a communication function, such as an alarm clock. Additionally, the blood pressure monitor11may include the alarm function, and the output time of the wake-up alarm may be input to the blood pressure monitor11by the user.

In another example, the measurement scheduled time setting unit44sets the measurement scheduled time using the wake-up time of the preceding day as the wake-up scheduled time. For example, the time the user woke up on March 5 is used as the wake-up scheduled time on March 6. The wake-up time is detected by, for example, the blood pressure monitor11. As an example, the blood pressure monitor11estimates, as a wake-up time, the time at which the user has removed the pressing cuff271from the upper arm. The action of the user removing the pressing cuff271from the upper arm can be detected based on, for example, an output of an acceleration sensor provided in the pressing cuff271. The wake-up time may be detected by the smartphone12. For example, the smartphone12estimates the time at which the user lifted the smartphone12as a wake-up time. The action of the user lifting the smartphone12may be detected based on an output of an acceleration sensor provided in the smartphone12. The smartphone12transmits, to the blood pressure monitor11, wake-up time information indicating the detected wake-up time.

The measurement control unit45controls the blood pressure measurement unit27. For example, in response to reception of a measurement start instruction signal from the input unit41, the measurement control unit45causes the blood pressure measurement unit27to measure the blood pressure. Furthermore, the measurement control unit45receives measurement scheduled time information from the measurement scheduled time setting unit44. The measurement control unit45causes the blood pressure measurement unit27to measure the blood pressure at a measurement scheduled time indicated by the received measurement scheduled time information.

The measurement control unit45controls operations associated with blood pressure measurement. The measurement control unit45controls the pump drive circuit273and the valve drive circuit275to perform blood pressure measurement in accordance with the oscillometric method. The measurement control unit45brings the valve274into a closed state via the valve drive circuit275and drives the pump272via the pump drive circuit273. Accordingly, air starts to be fed to the pressing cuff271. The pressing cuff271is inflated to compress the upper arm of the user. When the calculation of the blood pressure value is completed, the measurement control unit45stops the pump272via the pump drive circuit273and brings the valve274into an open state via the valve drive circuit275. Accordingly, air is exhausted from the pressing cuff271. The measurement control unit45monitors cuff pressure by using the pressure sensor276. In a case where cuff pressure exceeds an upper pressure limit before the calculation of the blood pressure value is completed, the measurement control unit45stops the pump272via the pump drive circuit273and brings the valve274into the open state via the valve drive circuit275.

The upper pressure limit is predetermined from the viewpoint of safety. The upper pressure limit is determined to be 300 mmHg, for example.

The measurement control unit45calculates the blood pressure value using the oscillometric method based on a pressure signal output from the pressure sensor276in a pressurizing process of feeding air to the pressing cuff271. The blood pressure value includes systolic blood pressure (SBP) and diastolic blood pressure (DBP), but is not limited to these. The measurement control unit45stores the calculated blood pressure value in the measurement result storage unit47in association with time information. The measurement control unit45can calculate a pulse rate as well as the blood pressure value.

The measurement notification unit46notifies the user of the timing at which the blood pressure is to be measured. The notification is provided using the display device23and/or the speaker25. In one example, the measurement notification unit46provides notification in a case where measurement is not performed from the wake-up scheduled time of the user to the time the predetermined time period after the wake-up scheduled time, and otherwise does not provide notification. The predetermined time period may be, for example, 10 minutes, 20 minutes, 30 minutes, etc. The wake-up scheduled time used in the measurement notification unit46may be the same as the wake-up scheduled time used in the measurement scheduled time setting unit44. For example, the measurement notification unit46receives the alarm data from the communication control unit43, and uses the alarm time indicated by the received alarm data as the wake-up scheduled time. In another example, the measurement notification unit46provides notification in a case where measurement is not performed from the wake-up time of the user for the day to the time the predetermined time period after the wake-up time, and otherwise does not provide notification.

Note that, in the present embodiment, the example has been described in which all of the functions of the blood pressure monitor11are realized by a general-purpose processor. However, some or all of the functions of the blood pressure monitor11may be realized by one or a plurality of dedicated processors.

Operation Example

FIG. 5schematically illustrates an operational flow for the blood pressure monitor11to measure the blood pressure of the user before and after wake-up. In step S51inFIG. 5, the control unit21acquires wake-up scheduled time information indicating the wake-up scheduled time of the user.

For example, the control unit21functions as the communication control unit43to receive alarm data indicating an alarm time set for the wake-up alarm, from the smartphone12via the communication interface26. The control unit21treats, as the wake-up scheduled time, the alarm time indicated by the received alarm data.

In step S52, the control unit21functions as the measurement scheduled time setting unit44, and sets the measurement scheduled time for the time the predetermined time period before the wake-up scheduled time.

In step S53, the control unit21functions as the measurement control unit45to control the blood pressure measurement unit27such that the pressure measurement unit27measures the blood pressure of the user at the measurement scheduled time set by the measurement scheduled time setting unit44.

In step S54, the control unit21determines whether the blood pressure has been measured after wake-up of the user. For example, the control unit21determines whether measurement has been performed from the wake-up scheduled time of the user to the time the predetermined time period after the wake-up scheduled time. In a case where the blood pressure has not been measured after wake-up of the user (step S54; No), in step S55, the control unit21functions as the measurement notification unit46to provide notification to prompt blood pressure measurement. For example, sound is emitted from the speaker25. Subsequently, the processing is ended. On the other hand, in a case where the blood pressure has been measured after wake-up of the user (step S54; Yes), the processing is ended without notification.

FIG. 6schematically illustrates an operational flow when the blood pressure monitor11measures the blood pressure in accordance with the oscillometric method. The control unit21starts blood pressure measurement when the current time reaches the measurement scheduled time or in response to a blood pressure measurement start instruction from the user.

In step S61inFIG. 6, the control unit21functions as the measurement control unit45to perform initialization for blood pressure measurement. For example, the control unit21initializes a memory region for processing.

Furthermore, the control unit21opens the valve274via the valve drive circuit275. Accordingly, the air inside the pressing cuff271is exhausted. Subsequently, the control unit21sets a current output value of the pressure sensor276as a reference value for the cuff pressure.

In step S62, the control unit21functions as the measurement control unit45to perform control of pressurizing the pressing cuff271. For example, the control unit21closes the valve274via the valve drive circuit275and drives the pump272via the pump drive circuit273. Accordingly, air is fed to the pressing cuff271to inflate the pressing cuff271, and a cuff pressure Pc gradually increases as illustrated inFIG. 7. The control unit21monitors the cuff pressure Pc by the pressure sensor276and acquires a pulse wave signal Pm representing a variable component of arterial volume.

In step S63inFIG. 6, the control unit21functions as the measurement control unit45and attempts to calculate the blood pressure value based on the pulse wave signal Pm acquired at this point in time. In a case where the blood pressure value fails to be calculated yet due to lack of data at this point in time (step S64; No), the processing from step S62to step S64is repeated as long as the cuff pressure Pc has not reached an upper pressure limit.

In a case where the blood pressure value can be calculated (step S64;

Yes), in step S65, the control unit21functions as the measurement control unit45to stop the pump272via the pump drive circuit273and to open the valve274via the valve drive circuit275. Accordingly, the air inside the pressing cuff271is exhausted. In step S66, the control unit21functions as the measurement control unit45to save the measurement results in the storage device22, and further functions as the display control unit42to cause the display device23to display the measurement results.

Note that the operational flow illustrated inFIG. 5orFIG. 6is merely an example and that the procedure and contents of the processing can be appropriately changed. For example, the processing in steps S54and S55may be deleted. In this case, the smartphone12may execute processing similar to the processing in steps S54and S55. Additionally, inFIG. 6, the calculation of the blood pressure value is executed in the pressurizing process in which air is fed to the pressing cuff271, but may be executed in a depressurizing process in which the air inside the pressing cuff271is exhausted.

Effects

The blood pressure monitor11having the configuration described above sets the measurement scheduled time for the time the predetermined time period before the wake-up scheduled time of the user, and measures the blood pressure of the user at the measurement scheduled time. This allows the blood pressure of the user to be measured immediately before wake-up.

As a result, blood pressure changes before and after wake-up can be observed. This enables, for example, detection of a transient blood pressure variation in which the blood pressure surges suddenly and then decreases, and which may occur immediately before wake-up.

In one example, the blood pressure monitor11uses the earliest alarm time of the plurality of alarm times set for the wake-up alarm as the wake-up scheduled time to set the measurement scheduled time. Accordingly, blood pressure measurement can be more reliably performed before the user wakes up. In another example, the blood pressure monitor11sets the measurement scheduled time using the wake-up time of the user for the preceding day as the wake-up scheduled time. Accordingly, blood pressure measurement can be more reliably performed before the user wakes up.

The blood pressure monitor11provides notification to prompt the user to measure the blood pressure in a case where the blood pressure has not been measured after wake-up of the user. Accordingly, the blood pressure is more reliably measured after wake-up. As a result, it is possible to more reliably observe blood pressure changes before and after wake-up.

Modified Examples

Note that the invention is not limited to the embodiments described above.

Human beings are known to have a shallow sleep depth and a high heart rate as the activity of the sympathetic nerves increases during sleep. In this state, the blood pressure is likely to surge suddenly. Thus, by measuring the blood pressure when the user is in a shallow sleep state or has a high heart rate during sleep, a high blood pressure caused by a sudden surge in blood pressure can be detected.

FIG. 8schematically illustrates an example of a hardware configuration of the blood pressure monitor80according to an embodiment. InFIG. 8, components similar to those illustrated inFIG. 2are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

The blood pressure monitor80illustrated inFIG. 8corresponds to the blood pressure monitor11illustrated inFIG. 2supplemented with an acceleration sensor81. The acceleration sensor81is, for example, a3-axis acceleration sensor. The acceleration sensor81is attached to the user. The acceleration sensor81is provided in the pressing cuff271. An output of the acceleration sensor81is provided to the control unit21. With the pressing cuff271attached to the user, the output of the acceleration sensor81changes depending on the body motion of the user. Human beings have large body motions when the sleep is shallow (REM sleep state), and have small body motions when the sleep is deep (non-REM sleep state). Thus, whether the sleep is shallow or deep can be determined based on the output of the acceleration sensor81.

FIG. 9schematically illustrates an example of a software configuration of the blood pressure monitor80. InFIG. 9, elements similar to those illustrated inFIG. 4are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

The blood pressure monitor80illustrated inFIG. 9corresponds to the blood pressure monitor80illustrated inFIG. 4supplemented with a sleep detection unit91. The sleep detection unit91detects the depth of sleep of the user based on the output of the acceleration sensor81. For example, as illustrated inFIG. 10, the sleep detection unit91performs detection within a time range from a time a predetermined time period T1before a measurement scheduled time to the measurement scheduled time. The predetermined time period T1may be the same as or different from a time difference T0between the measurement scheduled time and the wake-up scheduled time. In response to detection of shallow sleep, the sleep detection unit91provides a detection signal to the measurement control unit45.

In response to reception of a detection signal from the sleep detection unit91, the measurement control unit45starts blood pressure measurement. In a case of receiving no detection signal from the sleep detection unit91, the measurement control unit45starts blood pressure measurement at the measurement scheduled time. In other words, the measurement control unit45causes the blood pressure measurement unit27to measure the blood pressure of the user when the sleep of the user is shallow within the time range ending at the measurement scheduled time, and causes blood pressure measurement unit27to measure the blood pressure of the user at the measurement scheduled time in a case where the sleep of the user is not shallow within the time range.

FIG. 11schematically illustrates an operational flow for the blood pressure monitor80to measure the blood pressure of the user before and after wake-up. The processing in steps S111, S112, S116, and S117inFIG. 11is similar to the processing in steps S51, S52, S54, and S55illustrated inFIG. 5.

In step S111inFIG. 11, the control unit21acquires wake-up scheduled time information indicating the wake-up scheduled time of the user. In step S112, the control unit21functions as the measurement scheduled time setting unit44, to set the measurement scheduled time for a time a predetermined time period (for example, 10 minutes) before the wake-up scheduled time.

In step S113, when the current time reaches a time a predetermined time period (e.g., 15 minutes) before the measurement scheduled time, the control unit21functions as the sleep detection unit91to determine whether the sleep of the user is shallow. In a case where the control unit21determines that the sleep is shallow (step S113; Yes), the processing proceeds to step S115.

In a case where the control unit21determines that the sleep is deep (step S113; No), the processing proceeds to step S114. In a case where the current time has not reached the measurement scheduled time (step S114; No), the processing returns to step S113. In a case where the current time has reached the measurement scheduled time (step S114; Yes), the processing proceeds to step S115.

In step S115, the control unit21functions as the measurement control unit45to control the blood pressure measurement unit27such that the blood pressure measurement unit27measures the blood pressure of the user. The control unit21causes the blood pressure measurement unit27to measure the blood pressure of the user when the sleep detection unit91detects that the sleep of the user is shallow within a time range ending at the measurement scheduled time, and causes the blood pressure measurement unit27to measure the blood pressure of the user at the measurement scheduled time in a case where the sleep detection unit91does not detect that the sleep of the user is shallow within the time range.

In step S116, the control unit21determines whether the blood pressure has been measured after wake-up of the user. In a case where the blood pressure has not been measured after wake-up (step S116; No), in step S117, the control unit21functions as the measurement notification unit46to provide notification to prompt blood pressure measurement. Subsequently, the processing is ended. In a case where the blood pressure has been measured after wake-up (step S116; Yes), the processing is ended without notification.

According to the blood pressure monitor80having the configuration described above, the blood pressure can be measured at timing immediately before wake-up of the user when the blood pressure is predicted to be high. As a result, blood pressure changes before and after wake-up can be effectively observed.

In contrast to the above description, the blood pressure monitor80may measure the blood pressure of the user when the sleep of the user is deep within a time range ending at the measurement scheduled time.

The sleep detection unit91of the blood pressure monitor80may detect the depth of sleep at multiple (e.g., four) levels. In this case, the measurement control unit45may control the blood pressure measurement unit27such that the blood pressure measurement unit27measures the blood pressure at the measurement scheduled time set by the measurement scheduled time setting unit44, and may output measurement results including a blood pressure measurement value and a level representing the depth of the sleep. The measurement results are useful to the physician to know the blood pressure status of the user.

FIG. 12schematically illustrates an example of a hardware configuration of a blood pressure monitor120according to an embodiment. InFIG. 12, components similar to those illustrated inFIG. 2are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

The blood pressure monitor120illustrated inFIG. 12corresponds to the blood pressure monitor11illustrated inFIG. 2supplemented with a heart rate sensor121. The heart rate sensor121measures the heart rate of the user. The heart rate sensor121is configured to be attachable to the user. For example, the heart rate sensor121is provided in the pressing cuff271. An output of the heart rate sensor121is provided to the control unit21. The heart rate sensor121corresponds to a heart rate measurement unit of the present invention.

FIG. 13schematically illustrates an example of a software configuration of the blood pressure monitor120. InFIG. 13, elements similar to those illustrated inFIG. 4are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

The blood pressure monitor120illustrated inFIG. 13corresponds to the blood pressure monitor11illustrated inFIG. 4supplemented with a heart rate measurement control unit131. The heart rate measurement control unit131controls the heart rate sensor121. For example, the heart rate measurement control unit131drives the heart rate sensor121within a time range from a time a predetermined time period before a measurement scheduled time to the measurement scheduled time. The heart rate measurement control unit131provides the measurement control unit45with a measurement value of the heart rate obtained by the heart rate sensor121.

The measurement control unit45causes the blood pressure measurement unit27to measures the blood pressure of the user when the heart rate of the user exceeds a threshold (e.g.,80bpm) within a time range ending at the measurement scheduled time, and causes the blood pressure measurement unit27to measure the blood pressure of the user at the measurement scheduled time in a case where the heart rate of the user has not exceeded the threshold within the time range.

FIG. 14schematically illustrates an operational flow for the blood pressure monitor120to measure the blood pressure of the user before and after wake-up. The processing in steps S141, S142, S146, and S147inFIG. 14is similar to the processing in steps S51, S52, S54, and S55illustrated inFIG. 5.

In step S141inFIG. 14, the control unit21acquires wake-up scheduled time information indicating the wake-up scheduled time of the user. In step S142, the control unit21functions as the measurement scheduled time setting unit44to set the measurement scheduled time for a time a predetermined time period before the wake-up scheduled time.

When the current time reaches a time a predetermined time period before the measurement scheduled time, the control unit21drives the heart rate sensor121to measure the heart rate of the user. In step S143, the control unit21functions as the measurement control unit45to determine whether the heart rate of the user has exceeded a threshold. In a case where the heart rate of the user has exceeded the threshold (step S143; Yes), the processing proceeds to step S145.

In a case where the heart rate of the user has not exceeded the threshold (step S143; No), the processing proceeds to step S144. In a case where the current time has not reached the measurement scheduled time (step S144; No), the processing returns to step S143. In a case where the current time has reached the measurement scheduled time (step S144; Yes), the processing proceeds to step S145.

In step S145, the control unit21functions as the measurement control unit45to control the blood pressure measurement unit27to measure the blood pressure of the user. The control unit21causes the blood pressure measurement unit27to measure the blood pressure of the user when the heart rate of the user exceeds the threshold within a time range ending at the measurement scheduled time, and causes the blood pressure measurement unit27to measure the blood pressure of the user at the measurement scheduled time in a case where the heart rate of the user has not exceeded the threshold within the time range.

In step S146, the control unit21determines whether the blood pressure has been measured after wake-up of the user. In a case where the blood pressure has not been measured after wake-up (step S146; No), in step S147, the control unit21functions as the measurement notification unit46to provide notification to prompt blood pressure measurement. Subsequently, the processing is ended. In a case where the blood pressure has been measured after wake-up (step S146; Yes), the processing is ended without notification.

According to the blood pressure monitor120having the configuration described above, the blood pressure can be measured at timing immediately before wake-up of the user when the blood pressure is predicted to be high. As a result, blood pressure changes before and after wake-up can be effectively observed.

Additionally, the predetermined time period used in calculating the measurement scheduled time may be determined by learning.

FIG. 15schematically illustrates an example of a software configuration of a blood pressure monitor150according to an embodiment. InFIG. 15, elements similar to those illustrated inFIG. 4are given the same reference numerals, and descriptions thereof will be omitted as appropriate. The blood pressure monitor150illustrated inFIG. 15corresponds to the blood pressure monitor11illustrated inFIG. 4supplemented with a determination unit151. With respect to a hardware configuration, the blood pressure monitor150is similar to the blood pressure monitor11.

Based on the measurement results obtained by measuring the blood pressure of the user at a time before the measurement scheduled time for a plurality of days, the determination unit151determines a time used in calculating the measurement scheduled time. For example, the blood pressure monitor150executes processing for measuring the blood pressure of the user at a time 10 minutes before the measurement scheduled time for a plurality of days, and determines the average value of blood pressure measurement values obtained by the processing. The average value is referred to as a first average value. The blood pressure measurement values are, for example, measurement values of systolic blood pressure. Subsequently, the blood pressure monitor150executes processing for measuring the blood pressure of the user at a time 15 minutes before the measurement scheduled time for a plurality of days, and determines the average value of blood pressure measurement values obtained by the processing. The average value is referred to as a second average value. Further subsequently, the blood pressure monitor150executes processing for measuring the blood pressure of the user at a time 20 minutes before the measurement scheduled time for a plurality of days, and determines the average value of blood pressure measurement values obtained by the processing. The average value is referred to as a third average value. The determination unit151compares the first average value, the second average value, and the third average value with one another, and determines the time corresponding to the highest average value to be the time used in calculating the measurement scheduled time. For example, in a case where the second average value is the largest, then the time used in calculating the measurement scheduled time is determined to be 15 minutes.

According to the blood pressure monitor150having the configuration described above, the blood pressure can be measured at timing immediately before wake-up of the user when the blood pressure is likely to be high. As a result, blood pressure changes before and after wake-up can be effectively observed.

Note that the present invention is not limited to the embodiments described above, and various modifications can be made in an implementation stage without departing from the gist. Furthermore, each of the embodiments may be implemented in combination as appropriate to the extent possible, and in this case, combined effects can be obtained. Also, the embodiments described above include various stages of invention, and various inventions may be extracted by appropriately combining the described plurality of disclosed constituent elements.

The part or whole of the embodiments described above can be described as, but not limited to, the following supplementary note.

Supplementary Note 1

A blood pressure measurement device (11) including:a blood pressure measurement unit (27) configured to measure a blood pressure of a user,a setting unit (44) configured to set a measurement scheduled time for a timea predetermined time period before a wake-up scheduled time of the user, anda measurement control unit (45) configured to cause the blood pressure measurement unit to measure the blood pressure of the user in accordance with the set measurement scheduled time.

REFERENCE NUMERALS LIST