Blood pressure measuring device

Abstract

Blood pressure measuring device (100) which is provided with a cuff (150) which compresses a measuring point by being wrapped around it, which has: a sensor (132) which detects a behavior of the cuff (150); and a control unit (122) which detects a detection amount for an index of blood pressure based on an output signal from the sensor (132), wherein the control unit (122) measures the blood pressure based on the detection amount, The blood pressure measuring device further comprises a storage unit (123B) which stores a history of the detection amount detected by the control unit (122), and The control unit (122) evaluates the wrapping strength of the cuff (150) by comparing the detection amount, which is detected based on the output signal of the sensor (132), with a history of the detection amount, which is stored in the memory unit (123B).

Description

Technical area

[0001] The present invention relates to a blood pressure measuring device, and more specifically to a blood pressure measuring device for wrapping a cuff and compressing a measuring point when the blood pressure is measured.

[0002] JP S63 - 189128 A discloses a blood pressure measuring device for wrapping a cuff and compressing a measuring point when measuring blood pressure, wherein the wrapping strength is measured based on the pressure of the cuff and compared with a reference value.

[0003] JP 2007 167 171 A discloses a blood pressure measuring device for wrapping a cuff and compressing a measuring point when the blood pressure is measured, wherein information about a cuff compliance property, obtained from a change in the internal pressure and volume of the measuring bladder in which a predetermined amount of air is enclosed, is pre-stored in a memory section.The blood pressure calculation section comprises a pulse wave amplitude detection section, which determines the pulse wave amplitude by means of the pulse wave detection section in a process of changing the internal pressure in the measuring bladder by changing the externally applied pressure on the measuring bladder by means of the pressure section, and a correction section, which corrects the pulse wave amplitude determined by the pulse wave amplitude detection section using the information about the cuff compliance property read from the memory section, whereby the blood pressure is calculated based on the pulse wave amplitude corrected by the correction section. Background of the state of the art

[0004] Blood pressure is one of the indicators used to analyze circulatory diseases, and conducting a risk assessment based on blood pressure is effective in preventing cardiovascular diseases such as stroke, heart failure, and myocardial infarction. Traditionally, diagnosis was made using blood pressure measured at a medical facility during a hospital visit, health check-up, or similar occasion (occasional blood pressure). However, research in recent years has shown that blood pressure measured at home (home blood pressure) is more useful in diagnosing circulatory disease than occasional blood pressure. This has led to the widespread adoption of home blood pressure monitors, with it estimated that over 30 million are present in homes across Japan.

[0005] To accurately measure blood pressure with a blood pressure monitor, the cuff must be correctly wrapped around the measurement site, such as the upper arm. However, with previous blood pressure monitors, it was difficult to determine whether the cuff was correctly positioned, and placement varied depending on the individual, leading to the problem of inaccurate blood pressure measurements.

[0006] With regard to such conventional problems, patent literature 1 (JP 2005-305028A), patent literature 2 (JP H02 - 114 934 A) and patent literature 3 (JP 2008-188197A) publish, for example, technologies to determine whether the strength with which the cuff is wrapped is correct, based on the amount of air sent to the cuff, and the way in which the cuff pressure increases at the start of the blood pressure measurement during the process of increasing the cuff pressure. List of citations from patent literature Patent Literature 1: JP 2005-305028A Patent literature 2: JP H02 - 114 934 A Patent Literature 3: JP 2008-188197A Summary of the invention: Technical problem

[0007] Even if the same amount of air is sent to the cuff during the blood pressure increase process, as described above, the way in which the cuff pressure may increase will change, depending not only on the cuff's wrapping thickness but also on the dimensions (circumference) and quality of the measuring point (hardness, etc.) around which the cuff is wrapped. Accordingly, with the technologies published in patent literature 1 to 3, which determine wrapping thickness based solely on the way in which the cuff pressure increases, it is difficult to alert the person being measured to a variation in wrapping thickness when such a variation occurs, since there is no easy way to compare the results of determining wrapping thickness each time a measurement is taken.

[0008] The present invention was formulated in view of the situation in question and has the objective of detecting a variation in the wrapping thickness of the cuff when such a variation occurs in a blood pressure measuring device and of alerting the person being measured to this fact. Solution to the problem

[0009] A blood pressure measuring device according to the present invention is defined in independent claim 1 and 9. Preferably, the control unit detects an amount that is related to an amount of arterial volume change at the measuring point around which the cuff is wrapped.

[0010] Preferably, the control unit detects a pressure pulse wave amplitude of an artery at the measurement location around which the cuff is wrapped.

[0011] Preferably, the storage unit stores the course of the detection amount together with a course of a blood pressure wave, which is measured based on the detection amount.

[0012] Preferably, the control unit evaluates the wrapping thickness of the cuff around the measuring point by comparing a maximum value of the detected detection amount with a maximum value in the detection amount curve stored in the memory unit.

[0013] Preferably, the control unit evaluates the wrapping thickness of the cuff around the measuring point by comparing the detected detection amount with the detection amount corresponding to one or more blood pressure values ​​from a systolic blood pressure, a mean blood pressure and a diastolic blood pressure of the blood pressure values ​​in each course of the detection amount stored in the storage unit.

[0014] Preferably, the control unit evaluates the wrapping thickness of the cuff around the measurement point by comparing a detection value of the detected detection amount with the detection amount corresponding to a representative value of the measured blood pressure values, based on the detection amount in each course of the detection amount stored in the detected memory unit.

[0015] Preferably, the detection amount is a volume of Korotkoff sounds of an artery at the measurement location around which the cuff is wrapped, based on the sensor's output signal. Advantageous effects of the invention

[0016] According to the present invention, the wrapping thickness of the cuff is evaluated. The person being measured is thereby able to recognize whether there is a variation in the wrapping thickness, based on the results of the evaluation. Brief description of the drawings Fig. Figure 1 is a drawing showing the external appearance of a blood pressure measuring device 100, which serves as a first embodiment of the blood pressure measuring device of the present invention. Fig. 2 is a drawing which schematically depicts a usage state of the blood pressure monitor. Fig. 1 shows. Fig. 3 is a functional block diagram, which shows a configuration of the blood pressure monitor. Fig. 1 shows. Fig. Figure 4 is a diagram showing an example of the pressure pulse wave amplitude generated by a pulse wave signal detection unit of the Fig. 3 is detected. Fig. Figure 5 is a diagram showing another example of the pressure pulse wave amplitude generated by the pulse wave signal detection unit of the Fig. 3 is detected. Fig. 6 is a flowchart of the blood pressure measurement processing, which is carried out in the blood pressure monitor of the Fig. 1 is executed. Fig. 7 is a diagram showing an example screen displayed on a display unit of the Fig. 1 is displayed. Fig. Figure 8 is a diagram which schematically shows the state of use of a blood pressure measuring device, which serves as a second embodiment of the blood pressure measuring device of the present invention. Fig. Figure 9 is a functional block diagram, which shows a configuration of the blood pressure monitor. Fig. 8 shows. Fig. 10 is a diagram that exemplifies Korotkoff sounds produced by the blood pressure monitor of the Fig. 8 have been detected. Fig. Figure 11 is a diagram which schematically shows a state of use of a blood pressure measuring device, which serves as a third embodiment of the blood pressure measuring device of the present invention. Fig. 12 is a functional block diagram, which shows a configuration of the blood pressure monitor of the Fig. 11 shows. Fig. Figure 13 is a diagram showing an example voltage value from an arterial volume detection circuit in the blood pressure monitor of the Fig. 11 has been issued. Description of the embodiments

[0017] The following describes embodiments of a blood pressure measuring device of the present invention with reference to the drawings. In the following description, the same reference numerals are given to the same components and assemblies. Their names and functions are also the same. Note that in the following embodiments, the cuff is an air bellows and that the measurement site around which the cuff is wrapped is intended to be the upper arm, although the measurement site is not limited to the upper arm. 1. First embodiment

[0018] A blood pressure measuring device which measures blood pressure according to an oscillometric method is described as a first embodiment of the blood pressure measuring device of the present invention. 1-1. External configuration of the blood pressure monitor

[0019] Fig. Figure 1 shows an external appearance of a blood pressure measuring device 100, which serves as a first embodiment of the blood pressure measuring device of the present invention. Fig. Figure 2 is a drawing which schematically depicts a usage state of the blood pressure monitor 100. Fig. 1 shows.

[0020] With reference to Fig. 1 and Fig. 2. The blood pressure monitor 100 is primarily supplied with a main unit 110 and a cuff 150. In the case where the blood pressure measurement is carried out by the blood pressure monitor 100, the cuff 150 is wrapped around a measuring point 200.

[0021] The main unit 110 comprises a display unit 114 and an operating unit 115. The display unit 114 shows the results of blood pressure measurements, pulse rates, etc., using numerical values, graphs, and similar elements in a way that allows for visual confirmation. A liquid crystal display or similar device can, for example, be used as this display unit 114. A circuit breaker, a measuring switch, and similar components are, for example, arranged on the operating unit.

[0022] The cuff 150 is designed to be wrapped around the measurement site of the person being measured and has a belt-like outer shape. The cuff 150 contains an air bellows 151, which serves as a fluid bag for compressing the measurement site.

[0023] The cuff 150 and the main unit 110 are connected via an air hose 140, which serves as a connecting hose. The air hose 140 consists of a flexible hose, one end of which is connected to an air system component 131 for use in blood pressure measurement, which is provided in the main unit 110 and will be discussed later, and the other end of which is connected to the aforementioned air bellows 151 of the cuff 150. 1-2. Block configuration of the blood pressure monitor

[0024] Fig. Figure 3 is a functional block diagram showing a configuration of the 100 blood pressure monitor.

[0025] With reference to Fig. 3. The air system component 131 is provided for use in blood pressure measurement, i.e., for supplying air to or deflating air from the air bulb 151, which is contained in the cuff 150, via the air hose 140 within the main unit 110 of the blood pressure monitor 100. A pressure sensor 132, which detects the pressure within the air bulb 151, and a pump 134 and a valve 135 for expanding and contracting the air bulb 151 are included in the air system component 131 for use in blood pressure measurement. An oscillation circuit 125, a pump driver circuit 126, and a valve driver circuit 127 are also provided within the main unit 110 with respect to the air system component 131 for use in blood pressure measurement.

[0026] In the present embodiment, a sensor which detects the behavior of the cuff 150 is represented by the pressure sensor 132.

[0027] Furthermore, the main unit 110 contains: a control unit 122 for centrally controlling and monitoring the units, a storage unit 123A which stores a program for instructing the control unit 122 to perform the predefined operations, a storage unit 123B for storing various information, such as measured blood pressure values, a display unit 114 for displaying various information, including blood pressure measurement results, the operating unit 115, which is used to enter various instructions for performing the measurement, a timer 129 which has a clock function, and a power supply unit 124 for supplying power to the control unit 122 and the functional blocks. The control unit 122 contains a processor, such as a CPU (central processing unit).

[0028] The 123A and 123B storage units each consist of a storage medium. These storage units can be implemented using a single storage medium or can consist of separate storage media. Examples of storage media include non-volatile media for storing programs, such as CD-ROM (Compact Disc Read-Only Memory), DVD-ROM (Digital Alternating Disc Read-Only Memory), USB (Universal Serial Bus) memory, memory card, FD (Flexible Disk), hard disk, magnetic tape, cassette tape, MO (Magnetic Optical Disc), MD (MiniDisc), IC (Integrated Circuit) card (excluding memory card), optical card, mask ROM, EPROM, and EEPROM (Electronically Erasable Programmable Read-Only Memory).

[0029] The pressure sensor 132 detects the pressure inside the air bellows 151 (hereinafter referred to as "cuff pressure," if appropriate) and outputs a signal, dependent on the detected pressure, to the oscillation circuit 125. The pump 134 supplies air to the air bellows 151. The valve 135 opens and closes when it maintains the pressure inside the air bellows 151 and when it discharges the air inside the air bellows 151. The oscillation circuit 125 outputs an oscillation frequency signal, dependent on the output value of the pressure sensor 132, to the control unit 122. The pump driver circuit 126 controls the operation of the pump 134 based on a control signal provided by the control unit 122. The valve driver circuit 127 controls the opening and closing of the valve 135, based on a control signal provided by the control unit 122.

[0030] The control unit 122 includes a pulse wave signal detection unit 122A, which detects the arterial volume change superimposed on the cuff pressure as a pressure change (pressure pulse wave amplitude) by processing the signal output by the oscillation circuit 125; a blood pressure measurement unit 122B, which measures the blood pressure based on the pressure pulse wave amplitude detected by the pulse wave signal detection unit 122A; and an evaluation unit 122P, which evaluates the wrapping tightness of the cuff 150 in the current measurement by comparing the pressure pulse wave amplitude of the present measurement with the pressure pulse wave amplitude of previous measurements. The evaluation unit 122P outputs an evaluation result, for example, by displaying the evaluation result on the display unit 114.An example of the pressure pulse wave amplitude detected by the pulse wave signal detection unit 122A is shown in . Fig. 4 shown.

[0031] The change in a pulse wave signal (SIG) over time is caused by Fig. 4 shown. The pulse wave signal SIG of the Fig. 4 indicates the change in the pulse wave when the cuff pressure is constant. The pulse wave signal SIG of the Fig. 4 takes an amplitude PX as its maximum and changes it so that the same pattern is repeated at each fixed time period.

[0032] The control unit 115 includes a power switch 115A to switch the power supply for the blood pressure monitor 100 on and off, a measuring switch 115B, which is operated when the blood pressure monitor is prompted to start the blood pressure measurement, a stop switch 115C, which is operated to stop a blood pressure measurement process that is currently being carried out, a user selection switch 115D to select a measurement subject for the blood pressure monitor 100, and a recording recall switch 115E, which is operated to display data, such as blood pressure values, pulse rates and similar information, which are stored in the memory unit 123B, on the display unit 114.

[0033] The results of the blood pressure and pulse rate measurements are stored in the memory unit 123B for each person being measured. The stored measurement results are displayed on the display unit 114 in a manner that allows for visual confirmation, using numerical values, graphs, and similar visuals as a result of operating the recording recall switch 115E. 1-3. Change in the pressure pulse wave amplitude that follows the change in cuff pressure.

[0034] With the 100 blood pressure monitor, the pressure pulse wave amplitude changes in response to a change in cuff pressure. This change in pressure pulse wave amplitude following a change in cuff pressure is shown in (A) and (B) of the Fig. 5 shown.

[0035] Firstly, with reference to (A) the Fig. 5. The pressure pulse wave signal does not appear when the cuff pressure is less than a specified value and appears when the cuff pressure reaches the specified value. Thereafter, following an increase in cuff pressure, the pressure pulse wave amplitude increases overall while the specified change pattern is repeated. Following an increase in cuff pressure, after reaching a local maximum, the pressure pulse wave amplitude decreases overall while the specified change pattern is repeated. If the cuff pressure is greater than or equal to a specified value, the pressure pulse wave amplitude is no longer maintained. In (A) of the Fig. 5. A single change pattern is displayed by P1.

[0036] With the Blood Pressure Monitor 100, blood pressure measurement is based on the pressure pulse wave amplitude. Specifically, for example, during the process of reducing the cuff pressure, which has been increased to exceed the value described above, the cuff pressure at which the pressure pulse wave amplitude increases rapidly is used as the systolic blood pressure value, the cuff pressure at which the pressure pulse wave amplitude decreases rapidly is used as the diastolic blood pressure value, and the cuff pressure at which the pressure pulse wave amplitude exhibits a local maximum is used as the average blood pressure value.

[0037] The pressure pulse wave amplitude in the case where the cuff pressure is in the same range as (A) of the Fig. 5 changes, becomes in (B) the Fig. 5 shown. Note that the state shown in (B) of the Fig. Figure 5 shows the pressure pulse wave amplitude in the case where the wrapping of the cuff 150 around the measuring point is looser than the state shown in (A). Fig. 5 is shown (hereafter referred to as a “loose wrapping”, if appropriate). Note that in (A) the Fig. 5 is assumed to indicate that the pressure pulse wave amplitude is displayed in the case where the cuff 150 is wrapped around the measuring point at a suitable thickness.

[0038] Compared with (A) the Fig. 5 tends the pressure pulse wave amplitude, which in (B) the Fig. 5 is displayed, similarly to changing relative to the change in cuff pressure, although the overall amplitude value is smaller than the pressure pulse wave amplitude shown in (A) of the Fig. 5 is shown.

[0039] Note that if the cuff 150 is wrapped too tightly around the measurement site, the pressure pulse wave amplitude will increase more overall than if the wrapping is correct. However, if the cuff 150 is wrapped so tightly around the measurement site that blood has difficulty flowing through the blood vessels, the pressure pulse wave amplitude will be lower than if the wrapping is correct.

[0040] In the present embodiment, the wrapping of the cuff 150 around the measuring point is evaluated based on the value of the pressure pulse wave amplitude, corresponding to the same cuff pressure (or cuff pressures which exhibit the same characteristics as the systolic blood pressure value, the diastolic blood pressure value, the average blood pressure value, etc.) for a multitude of measurements. 1-4. Storage mode of the pressure pulse wave amplitude

[0041] With the Blood Pressure Monitor 100, the blood pressure and pulse wave amplitude values ​​obtained from the last blood pressure measurements are stored in the memory unit 123B as histories or trends for each person being measured. An example storage mode for these values ​​is shown in Tables 1 and 2. Table 1 Blood pressure value data ID Messung Datum-Zeit Benutzer Blutdruck Wert / Pulsrate Druckpulswelle Amplitudendaten 1 y1 / m1 / d1 h1:m1 A SYS1, DIA1, PLS1 PulsWelle1 2 y2 / m2 / d2 h2:m2 A SYS2, DIA2, PLS2 PulsWelle2 3 y3 / m3 / d3 h3:m3 A SYS3, DIA3, PLS3 PulsWelle3 4 y4 / m4 / d4 h4:m4 A SYS4, DIA4, PLS4 PulsWelle4 5 y5 / m5 / d5 h5:m5 A SYS5, DIA5, PLS5 PulsWelle5 ... ... ... ... ... ... ... ... ... Table 2 Pressure pulse wave amplitude data (Pulse wave 1) Manschettendruck (mm Hg) Druckpulswellenamplitude (mm Hg) 0 0,00 5 0,01 ... ... 85 2,20 ... ... 180 0,01 176 0,02 ... ... 0 0,00

[0042] The blood pressure data, shown in Table 1, contains IDs that combine data sets, including measurement date and time, information specifying the person being measured (the user), blood pressure values, pulse rates, and information specifying the pressure pulse wave amplitude data, which is stored separately. For example, the systolic blood pressure, the diastolic blood pressure, or the average blood pressure can be stored as the blood pressure, and the cuff pressure at the maximum pressure pulse wave amplitude can also be stored as the blood pressure value.

[0043] In the pressure pulse wave amplitude data, shown in Table 2, the change in the pressure pulse wave amplitude pattern, as e.g. with reference to (A) and (B) of the Fig. Figure 5 is shown for a variety of predefined cuff pressures.

[0044] In the example shown in Table 2, the pressure pulse wave amplitude data includes pressure pulse wave amplitudes for a variety of cuff pressures (blood pressures). Note that in the present embodiment, it is sufficient if at least the pressure pulse wave amplitudes used during the "evaluation of the wrapping strength" in the blood pressure measurement processing, which will be discussed later, are included in the pressure pulse wave amplitude data.In other words, for example, in the case where, during winding strength evaluation, the pressure pulse wave amplitudes corresponding to the systolic blood pressure values ​​obtained in the current blood pressure measurement are compared with the pressure pulse wave amplitudes corresponding to the systolic blood pressure values ​​stored as historical data, it is sufficient if at least the pressure pulse wave amplitudes corresponding to the systolic blood pressure values ​​are stored in the pressure pulse wave amplitude data for each measurement. Similarly, in the case where, during winding strength evaluation, the maximum values ​​of the pressure coil wave amplitudes stored as historical data are compared with the maximum value of the pressure pulse wave amplitude obtained in the current blood pressure measurement, it is sufficient if at least the maximum value of the pressure pulse wave amplitude is stored in the pressure pulse wave amplitude data for each measurement.

[0045] Information that identifies each segment of the pressure pulse wave amplitude data, such as "PulseWave1" in Table 2, is given to the pressure pulse wave amplitude data of each measurement. 1-5. Blood pressure measurement procedure

[0046] Fig. Figure 6 is a flowchart of the blood pressure measurement process performed in the blood pressure monitor 100. In the blood pressure monitor 100, this process is carried out by the control unit 122, which executes a program stored in the memory unit 123A (or in a recording medium that is removable from the main unit 110).

[0047] With reference to Fig. 6 During the blood pressure measurement process, the control unit 122 is first available at step S10 until the power switch 115A is operated, and proceeds with processing to step S20 when it is assessed that the power switch 115A has been operated.

[0048] In step S20, the control unit 122 initializes the blood pressure monitor 100. This initializes the internal pressure of the air bellows 151 of the cuff 150.

[0049] Next, in step S30, the control unit 122 receives the input signal of the information that selects a user, as a result of operating the user selection switch 115D. If it is determined that the information selection for a user has been entered, the control unit 122 proceeds to step S40. Note that in step S30, the control unit 122 generates a new ID for the blood pressure value data shown in Table 1 and allocates a memory location for the new ID. The date and time obtained at this point by the timer 129 are then stored as the date and time of the measurement belonging to the new ID, and information about the user for whom the input information was received in step S30 is stored as the user to whom the new ID belongs.

[0050] In step S40, the control unit 122 is ready until the measuring switch 115B is actuated. Once it is determined that the measuring switch 115B has been actuated, the control unit 122 proceeds to step S50.

[0051] In step S50, the control unit 122 causes the cuff pressure to be increased by causing the pump 134 to send air to the air bellows 151, and proceeds with processing to step S60.

[0052] In step S60, the control unit 122 assesses whether the cuff pressure has reached a prescribed pressure, based on the output signal of the pressure sensor 132. The control unit 122 returns to step S50 in the processing if it assesses that the prescribed pressure has not yet been reached, and proceeds to step S70 if it assesses that the prescribed pressure has been reached.

[0053] In step S70, the control unit 122 gradually reduces the cuff pressure by controlling the closed valve 135 to gradually open. Based on the pressure pulse wave signal superimposed on the signal detected by the pressure sensor 132, the control unit 122 calculates the blood pressure (systolic and diastolic) according to a prescribed procedure in step S80. In step S90, the control unit 122 instructs the storage unit 123B to store the pressure pulse wave amplitude at that time and proceeds to step S100. The pressure pulse wave amplitude stored in step S90 is equal to the value of the pressure pulse wave amplitude relative to the cuff pressure at that time in the pressure pulse wave amplitude data (see Table 2), which is shown in Table 2.

[0054] In step S100, the control unit 122 assesses whether the blood pressure calculation has been completed. If it is determined that it has been completed (YES in step S100), processing proceeds to step S110. Conversely, if it is determined that it has not been completed, processing returns to step S70.

[0055] In step S110, the control unit 122 compares the pressure pulse wave amplitude value obtained as a result of the current measurement with the pressure pulse wave amplitude values ​​obtained as a result of previous measurements and stored in the memory unit 123B. It generates information that evaluates the wrapping thickness of the cuff 150 of the current measurement based on the comparison result and proceeds to step S120. The types of comparison and evaluation referred to here will be discussed later.

[0056] In step S120, the control unit 122 instructs the display unit 114 to display the blood pressure values ​​obtained in step S80, together with the evaluation information generated in step S110, and proceeds with processing to step S130.

[0057] In step S130, the blood pressure values ​​(systolic blood pressure, diastolic blood pressure and / or average blood pressure) that were set in step S80 and displayed on the display unit 114 in step S120 are stored in the blood pressure data (Table 1), and the measurement process is ended.

[0058] Note that the blood pressure values ​​obtained belong to the user selected in step S30 and are stored in memory unit 123.

[0059] The control unit 122 also controls the valve 135 so that at the same time (or after) the display of the blood pressure values ​​in step S120 takes place, and releases the air into the air bellows 151. 1-6. Wrapping Strength Evaluation

[0060] The evaluation of the wrapping strength is described in step S110.

[0061] The control unit 122 first reads a value of the pressure pulse wave amplitude corresponding to the blood pressure value obtained as the initial value in the current blood pressure measurement. The blood pressure value referenced here can be, for example, the systolic blood pressure, the diastolic blood pressure, or the average blood pressure, and can also be the cuff pressure when the pressure pulse wave amplitude reaches its maximum value.

[0062] Next, taking into account the blood pressure measurement to date, a pressure pulse wave amplitude value, which is stored in Table 2, is read in the memory unit 123B together with the person being measured, for whom the information in Table 1 was entered at step S30, as a second value.

[0063] Note that, as with the value read here as the second value, in the case where a value corresponding to the systolic blood pressure is measured as the pressure pulse wave amplitude obtained during the current blood pressure measurement, the pressure pulse wave amplitude value, which corresponds similarly to the systolic blood pressure, is also read as the blood pressure measurement value to date. In the case where a value corresponding to the diastolic blood pressure is read, the pressure pulse wave amplitude value, which corresponds similarly to the diastolic blood pressure value, is also read as the blood pressure measurement value to date. In the case where a value corresponding to the average blood pressure is read, the pressure pulse wave amplitude value, which corresponds similarly to the average blood pressure, is also read as the blood pressure measurement value to date.

[0064] Similarly, the value that is read as the second value is the pressure pulse wave amplitude corresponding to the systolic blood pressure value or similar and can immediately be the previous measurement result for the subject for whom information was entered in step S30, or can be a representative value, such as the average, minimum or maximum value of a prescribed number (e.g. 5) of the most recent measurement results.

[0065] The control unit 122 then calculates the difference between the first and second values ​​(second value - first value) and evaluates the winding strength based on the value of this difference, REF. For example, the winding strength is evaluated as correct if REF is less than or equal to "A", as tight if REF exceeds "A", and as loose if REF is less than "-A".

[0066] The winding strength can also be evaluated across many levels. An example is described in which the winding strength is evaluated across, say, seven levels. The winding strength is evaluated as correct if REF is less than or equal to "A1", slightly tight if REF exceeds "A1" and is less than or equal to "A2", tight if REF exceeds "A2" and is less than or equal to "A3", very tight if REF exceeds "A3", slightly loose if REF is less than "-A1" but greater than or equal to "-A2", loose if REF is less than "-A2" but greater than or equal to "-A3", and very loose if REF is less than "-A3". Note that in this case, A1 to A3 are positive numbers, where A1 < A2 < A3. 1-7. Example display of the wrapping strength evaluation result

[0067] An example screen, which is displayed on display unit 114 in step S120, is shown in Fig. 7 shown.

[0068] With reference to Fig. 7. A systolic blood pressure value 402 (numeric value "162"), a diastolic blood pressure value 403 (numeric value "98"), a pulse value 404 (numeric value "92"), a current date and time 401 and an evaluation display section 40, which consists of a multitude of blocks, are displayed on a screen 400.

[0069] The evaluation display section 40 contains seven blocks, corresponding to seven evaluation levels, as described above. The block corresponding to the evaluation result from among the seven blocks is displayed differently from the other blocks (hatched block in Fig. 7) Note that in Fig. 7 the block around one above the middle is displayed in a different way and the evaluation result is shown as “slightly loose”.

[0070] In the present embodiment described above, the detection value for a blood pressure index, which is detected based on the output signal of a sensor (pressure sensor 132), consists of the pressure pulse wave amplitude, which is used to evaluate the winding strength. The pressure pulse wave amplitude also provides information relating to the magnitude of the arterial volume change.

[0071] Likewise, in the present invention, a first storage unit and a second storage unit consist of the storage unit 123B, which stores the blood pressure value data (Table 1) and the pressure pulse wave amplitude data (Table 2). Specifically, the second storage unit comprises a sub-area within the storage unit 123B that stores data associated with the blood pressure value data and the ID of the measurement data relating to the currently performed blood pressure measurement. The first storage unit also comprises a sub-area within the storage unit 123B that stores data associated with the IDs of the previous measurement data within the blood pressure value data.

[0072] An evaluation unit of the present invention consists of the evaluation unit 122P, which compares the wrapping thickness of the cuff 150 by comparing the pressure pulse wave amplitude in the current detection result and a pressure pulse wave amplitude that is stored as a history. Note that the evaluation unit 122P, for example, displays the evaluation result for the display unit 114 as the evaluation display section 40 in Fig. outputs 7. 2. Second embodiment 2-1. Configuration of the blood pressure monitor

[0073] A blood pressure monitor 100, which serves as an exemplary blood pressure measuring device of the present embodiment, performs the blood pressure measurement in accordance with Korotkoff sounds. A similar external configuration for the blood pressure monitor 100 of the first embodiment can be assumed.

[0074] Fig. Figure 8 is a drawing which schematically shows the state of use of the blood pressure measuring device 100 of the present embodiment, and Fig. Figure 9 is a functional block diagram of the blood pressure measuring device 100 of the present embodiment.

[0075] With reference to Fig. 8 and Fig. In addition to the blood pressure monitor 100 of the first embodiment, the blood pressure monitor 100 of the present embodiment is further provided with a microphone 80 inside the cuff 150.

[0076] In the blood pressure measuring device 100 of the present embodiment, the cuff 150 is wrapped around the measuring point 200, and Korotkoff sounds, which are produced as a result in which the artery within the measuring point 200 is constricted, are detected by the cuff 150 with the microphone 80.

[0077] Likewise, in the present embodiment, the control unit 122 includes a noise detection unit 122C, which detects noises emitted by the microphone 80, and a blood pressure measurement unit 122D, which performs a blood pressure measurement based on the noises detected by the noise detection unit 122C.

[0078] Note that the blood pressure measurement, which is carried out in the blood pressure measuring device 100 of the present embodiment according to Korotkoff sounds, using sounds which are emitted by the microphone 80, may use known technology, the description of which will not be repeated.

[0079] (A) the Fig. Figure 10 shows changes in the volume (level) of the Korotkoff sounds that follow changes in cuff pressure when the cuff wrapping thickness is correct (B). Fig. Figure 10 shows changes in the volume (level) of the Korotkoff sounds that follow changes in cuff pressure in the case where the wrapping thickness of the cuff is loose.

[0080] With reference to (A) and (B) of the Fig. 10 The overall level of Korotkoff noise decreases when the cuff is loosely wound.

[0081] Note that if the cuff tightens to 150 mm, the overall level of Korotkoff sounds increases compared to when the tightening is correct. However, if the cuff tightens to 150 mm, even enough to restrict or block blood flow, the overall level of Korotkoff sounds decreases compared to when the tightening is correct. 2-2. Wrapping Strength Evaluation

[0082] The wrapping strength evaluation in step S110 (see Fig. 6) is described by the evaluation unit 122P of the blood pressure measuring device 100 of the present embodiment.

[0083] The control unit 122 first reads a level of Korotkoff sounds corresponding to the blood pressure value obtained from the current blood pressure measurement. This blood pressure value could be, for example, the systolic, diastolic, or mean arterial pressure. The referenced blood pressure value could also be the cuff pressure when the level of Korotkoff sounds reaches its maximum.

[0084] Next, taking into account the blood pressure measurement to date, a level of Korotkoff sounds, which is stored in Table 2 in memory unit 123B together with the person being measured, for whom the information for Table 1 was entered at step S30, is read as a second value.

[0085] Note that, as with the value read here as the second value, in the case where a value corresponding to the systolic blood pressure is read as the level of Korotkoff sounds obtained with the current blood pressure measurement, the level of Korotkoff sounds that corresponds similarly to the systolic blood pressure value is also read as the blood pressure measurement value to date. In the case where a value corresponding to the diastolic blood pressure value is read, the level of Korotkoff sounds that corresponds similarly to the diastolic blood pressure value is also read as the blood pressure measurement value to date. In the case where a value corresponding to the average blood pressure value is read, the level of Korotkoff sounds that corresponds similarly to an average blood pressure value is also read as the blood pressure measurement value to date.

[0086] Similarly, the value that is read as the second value is the level of the Korotkoff sounds, which corresponds to the systolic blood pressure value or similar, and can immediately be the previous measurement result for the subject for whom the information was entered in step S30, or can be a representative value, such as the average value, a minimum value or a maximum value of a prescribed number (e.g. 5 times) of the most recent measurement results.

[0087] The control unit 122 then calculates the difference between the first and second values ​​(second value - first value) and evaluates the winding strength based on the value of this difference REF01. For example, the winding strength is evaluated as correct if REF01 is less than or equal to "B", as tight if REF01 exceeds "B", and as loose if REF01 is less than "-B".

[0088] Similarly, the winding strength can be evaluated across many levels. An example is described in which the winding strength is evaluated across, say, seven levels. The winding strength is evaluated as correct if REF01 is less than or equal to "B1", as slightly tight if REF01 exceeds "B1" and is less than or equal to "B2", as tight if REF01 exceeds "B2" and is less than or equal to "B3", as very tight if REF01 exceeds "B3", as slightly loose if REF01 is less than "-B1" but greater than or equal to "-B2", as loose if REF01 is less than "-B2" but greater than or equal to "-B3", and very loose if REF01 is less than "-B3". Note that in this case B1 to B3 are positive numbers, where B1 < B2 < B3.

[0089] In the present embodiment described above, a sensor which detects the behavior of the cuff consists of the microphone 80.

[0090] An evaluation unit of the present invention consists of the evaluation unit 122P, which compares the wrapping thickness of the cuff 150 by comparing the Korotkoff sounds in the current detection result with the Korotkoff sounds stored as a history. Note that the evaluation unit 122P transmits the evaluation result to the display unit 114 as the evaluation display section 40 in Fig. 7, for example. 3. Third embodiment 3-1. Configuration of the blood pressure monitor

[0091] A blood pressure monitor 100, which serves as an exemplary blood pressure measuring device of the present invention, performs the blood pressure measurement by detecting the arterial volume using a photoelectric sensor comprising a light-emitting element and a light-receiving element. A similar external configuration for the blood pressure monitor 100 of the first embodiment can be adopted.

[0092] Fig. Figure 11 is a drawing which schematically shows the state of use of the blood pressure measuring device 100 of the present embodiment, and Fig. Figure 12 is a functional block diagram of the blood pressure measuring device 100 of the present embodiment.

[0093] With reference to Fig. 11 and Fig. 12. In addition to the blood pressure monitor 100 of the first embodiment, the blood pressure monitor 100 of the present embodiment includes a photoelectric sensor 70, which consists of a light-emitting element 71 and a light-receiving element 72, a light-emitting element driver circuit 73, and an arterial volume detection circuit 74. In the present embodiment, a sensor which detects the behavior of the cuff 150 consists of the photoelectric sensor 70.

[0094] Likewise, the control unit 122 includes an arterial volume detection unit 122E, which detects the arterial volume based on the output signal of the arterial volume detection circuit 74, and a blood pressure measurement unit 122F, which measures the blood pressure values ​​based on the arterial volume detected by the arterial volume detection unit 122E.

[0095] The light-emitting element 71 emits light towards a portion of the radial artery extending within the measurement location 200 (e.g., in the wrist in the present embodiment) and consists, for example, of an LED (light-emitting diode). The light-receiving element is a component that receives light emitted by the light-emitting element 71, which has passed through and / or been reflected by the radial artery, and consists, for example, of a PD (photodiode).

[0096] To accurately detect arterial volume, near-infrared light, which eventually passes through the tissue of the living body part, is preferably used as the detection light, and components capable of emitting and receiving this near-infrared light are preferably used as the light-emitting element 71 and the light-receiving element 72, respectively. More specifically, near-infrared light near a wavelength of 940 nm is particularly preferably used as the detection light, which is emitted by the light-emitting element 71 and received by the light-receiving element 72. Note that the detection light is not limited to near-infrared light near 940 nm, and light near a wavelength of 450 nm, light near a wavelength of 1100 nm, or similar wavelengths can also be used.

[0097] The light-emitting element driver circuit 73 is a circuit for causing the light-emitting element 71 to emit light based on a control signal from the control unit 122, and causes the light-emitting element 71 to emit light by applying a prescribed amount of current to the light-emitting element 71. A direct current of approximately 50 mA is used, for example, as the current applied to the light-emitting element. The light-emitting element driver circuit 73 preferably uses a circuit that causes the light-emitting element 71 to emit pulsed light periodically by supplying a pulsed current with a prescribed duty cycle to the light-emitting element.Assuming that the light-emitting element 71 is thereby caused to emit pulsed light, it will be possible to suppress the power applied to the light-emitting element 71 per unit time and thus prevent it from heating up. Note that the arterial volume can be detected more frequently by setting the driver frequency of the light-emitting element 71 to a frequency (e.g., approximately 3 kHz) that is sufficiently higher than the frequency component (approximately 30 Hz) contained in the variation within the arterial volume to be detected.

[0098] The arterial volume detection circuit 74 is a circuit for generating a voltage signal corresponding to the amount of light received, based on the signal input from the light-receiving element 72, and for outputting the generated voltage signal to the control unit 122. Since the amount of light detected by the light-receiving element 72 changes relative to the arterial volume, the voltage signal generated by the arterial volume detection circuit 74 will also change relative to the arterial volume, and the arterial volume is thus used as the variation in the voltage value. The arterial volume detection circuit 74 includes processing circuits, such as...an analog filter circuit, a rectification circuit, an amplification circuit and an A / D (analog / digital) converter circuit, for example, and outputs the signal, which is entered as an analog value, as a digitized voltage signal.

[0099] (A) the Fig. Figure 13 shows the change in the voltage signal (voltage value) output by the arterial volume detection circuit 74 following a change in cuff pressure, in the case where the wrapping thickness of the cuff 150 is correct. (B) Fig. Figure 13 shows the change in the voltage signal (voltage value) output by the arterial volume detection circuit 74 following a value in the cuff pressure in the case where the wrapping thickness of the cuff 150 is loose.

[0100] With reference to (A) and (B), the output voltage value decreases overall when the cuff is wrapped loosely 150.

[0101] Note that if the cuff wrapping is too tight, the overall voltage output will increase compared to when the wrapping is correct. However, if the cuff wrapping is so tight that it restricts blood flow, the overall voltage output will decrease compared to when the wrapping is correct. 3-2. Wrapping Strength Evaluation

[0102] The wrapping strength evaluation in step S110 (see Fig. 6) is described by the evaluation unit 122P of the blood pressure measuring device 100 of the present embodiment.

[0103] The control unit 122 first reads a voltage value corresponding to the blood pressure value obtained as an initial reading from the current blood pressure measurement. This blood pressure value could be, for example, the systolic blood pressure, the diastolic blood pressure, or the mean blood pressure. Alternatively, the referenced blood pressure value could be the cuff pressure when the output voltage reaches its maximum value.

[0104] Next, taking into account the blood pressure measurement to date, a voltage value, which is stored in Table 2 in memory unit 123B together with the person being measured, for whom information was entered into the memory in step S30, is read out as a second value.

[0105] Note that, as with the value read here as the second value, in the case where a value corresponding to the systolic blood pressure is read as the voltage value obtained with the current blood pressure measurement, the voltage level that corresponds similarly to the systolic blood pressure is also read as the blood pressure measurement value to date. In the case where a value corresponding to the diastolic blood pressure is read, the voltage value that corresponds similarly to the diastolic blood pressure is also read as the blood pressure measurement value to date. In the case where a value corresponding to the average blood pressure is read, the voltage value that corresponds similarly to the average blood pressure is also read as a blood pressure measurement value to date.

[0106] Similarly, the value read out as the second value is the voltage value corresponding to the systolic blood pressure value or similar and can be the immediately previous measurement result for the person being measured, for whom information was entered in step S30, or can be a representative value, such as the average value, the minimum value or the maximum value for a prescribed number (e.g. 5 times) of the most recent measurement results.

[0107] The control unit 122 then calculates the difference between the first and second values ​​(second value - first value) and evaluates the winding strength based on the value of this difference REF02. For example, the winding strength is evaluated as correct if REF02 is less than or equal to "C", as tight if REF02 exceeds "C", and as loose if REF02 is less than "-C".

[0108] Similarly, the winding strength can be evaluated across multiple levels. For example, an example is described in which the winding strength is evaluated across seven levels. The winding strength is evaluated as being correct if REF02 is less than or equal to "C1", slightly tight if REF02 exceeds "C1" and is less than or equal to "C2", tight if REF02 exceeds "C2" and is less than or equal to "C3", very tight if REF02 exceeds "C3", slightly loose if REF02 is less than "-C1" but greater than or equal to "-C2", loose if REF02 is less than "-C2" but greater than or equal to "-C3", and very loose if REF02 is less than "-C3". Note that in this case C1 to C3 are positive numbers, where C1 < C2 < C3.

[0109] In the present embodiment described above, the information relating to the amount of arterial volume change, which is the detection amount for the blood pressure index detected based on the output of a sensor, consists of a voltage value output by the arterial volume detection circuit 74, which is used to evaluate the winding strength.

[0110] An evaluation unit of the present invention consists of the evaluation unit 122P, which evaluates the wrapping thickness of the cuff 150 by comparing the voltage value in the current detection result with a voltage value stored as a history. Note that the evaluation unit 122P transmits the evaluation result to the display unit 114 as the evaluation display section 40. Fig. 7, for example.

[0111] According to the published invention in the embodiments described above, the detection value for the blood pressure index is determined by using information output by a sensor based on the cuff's behavior during blood pressure measurement. The cuff tightness is evaluated as a result of the detection value, which is compared to a detection value stored as a history. The person taking the measurement is thus able to recognize whether there is a variation in the cuff tightness based on the evaluation result.

[0112] The embodiments published here are to be considered explanatory and non-restrictive in all respects. The technical scope of the invention is defined by the claims, and all modifications that fall within the meaning and scope of equivalence of the claims are to be included therein. The published technologies in each embodiment are also to be implemented in combination where possible. 40 Evaluation Display Unit 70 Photoelectric sensor 71 Light-emitting element 72 Light-receiving element 73 Light Emitting Element Driver Circuit 74 arterial volume detection circuit 80 microphone 100 blood pressure monitor 110 Main Unit 114 Display unit 115 Control unit 115A circuit breaker 115B Measuring switch 115C Stop switch 115D User Selection Switch 115E switch 122 Control unit 122A Pulse Wave Signal Detection Unit 122B Blood Pressure Measuring Unit 122C Noise Detection Unit 122D Blood Pressure Measuring Unit 122E arterial volume detection unit 122F Blood Pressure Measuring Unit 122P Evaluation Unit 123A, 123B storage unit 124 Power supply unit 125 Oscillation circuit 126 Pump driver circuit 127 Valve driver circuit 129 Time element 131 Air system component for use in blood pressure measurement 132 Pressure sensor 134 Pump 135 valve 140 air hose 150 cuff 151 Air bellows 200 measuring point 400 screen

Claims

[1] A blood pressure measuring device (100) provided with a cuff (150) which compresses a measuring site by being wrapped around it, comprising: a sensor (132) which detects a behavior of the cuff (150); and a control unit (122) which detects a detection amount for an index of blood pressure based on an output signal of the sensor (132), wherein the control unit (122) measures the blood pressure based on the detection amount, the blood pressure measuring device further comprises a storage unit (123B) which stores a history of the detection amount detected by the control unit (122), and the control unit (122) evaluates a wrapping strength of the cuff (150) by comparing the detection amount detected based on the output signal of the sensor (132) with a history of the detection amount stored in the storage unit (123B). [2] The blood pressure measuring device (100) according to claim 1, wherein the control unit (122) detects an amount related to an amount of arterial volume change in the measuring site around which the cuff (150) is wrapped. [3] The blood pressure measuring device (100) according to claim 2, wherein the control unit (122) detects a pressure pulse wave amplitude of an artery in the measuring site around which the cuffs (150) are wrapped. [4] The blood pressure measuring device (100) according to claim 1, wherein the storage unit (123B) stores the history of the detection amount in association with a history of a blood pressure value measured based on the detection amount. [5] The blood pressure measuring device (100) according to claim 1, wherein the control unit (122) evaluates the wrapping strength of the cuff (150) around the measurement site by comparing a maximum value of the detected detection amount and a maximum value in the history of the detection amount stored in the storage unit (123B). [6] The blood pressure measuring device (100) according to claim 1, wherein the control unit (122) evaluates the wrapping strength of the cuff (150) around the measurement site by comparing the detected detection amount with the detection amount corresponding to one or more blood pressure values ​​among a systolic blood pressure, an average blood pressure and a diastolic blood pressure of the blood pressure values ​​in each history of the detection amount stored in the storage unit (123B). [7] The blood pressure measuring device (100) according to claim 1, wherein the control unit (122) evaluates the wrapping strength of the cuff (150) around the measurement site by comparing a detection value of the detected detection amount with the detection amount corresponding to a representative value of the measured blood pressure values ​​based on the detection amount in each history of the detection amount stored in the detected storage unit (123B). [8] The blood pressure measuring device (100) according to claim 1, wherein the detection amount is a volume of the Korotkoff sounds of an artery in the measurement site around which the cuff (150) is wrapped, based on the output signal of the sensor (132). [9] Blood pressure measuring device (100) provided with a cuff (150) which compresses a measuring site by being wrapped therein, which comprises: a sensor (132) which detects a behavior of the cuff (150) caused by the compression of the measurement site and generates a detection amount; a storage unit (123B); a control unit (122) which stores the detection amounts received from the sensor (132) in the past in the storage unit (123B) and generates a history of detection amounts, wherein the control unit (122) evaluates a winding strength of the cuff (150) by comparing a newly obtained detection amount with the past history of the detection amounts stored in the storage unit (122B).

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