Electronic blood pressure monitor and method for measuring blood pressure

Abstract

An electronic blood pressure monitor (2100) comprising: Cuff (2101) attached to a blood pressure measuring point; Pressurization and depressurization means (2102, 2104, 2105, 2112, 2113) for adjusting a pressure applied to the cuff (2101); Pressure detection means (2103) for detecting a pressure in the cuff; Blood pressure calculating means (2120) for calculating a blood pressure value from a cuff pressure; Recording means (2122, 2123) for recording the blood pressure value, and Operating means (2130) for performing an operation, such as measuring blood pressure; wherein the blood pressure calculation means (2120) has a configuration adapted to calculate a calculation parameter for blood pressure by performing a predetermined calculation using a constant (α, β, ζ, ζtsys, η, ηtdia) previously set in view of a change in a pressure pulse wave amplitude indicative of a volume change in an artery at the time of blood pressure measurement; and the electronic blood pressure monitor (2100) also includes: Information acquisition means for separately acquiring measurement condition-related information relating to a condition of the user and / or a condition of the cuff (2101) at the time of blood pressure measurement; and Correction means for correcting the calculation parameter for blood pressure by correcting the constants (α, β, ζ, ζtsys, η, ηtdia) based on the information related to the measurement state when the information related to the measurement state is acquired by the information acquisition means, characterized in that the blood pressure calculation means (2120) for the blood pressure has a configuration adapted to calculate a calculation parameter for the systolic blood pressure based on a predetermined calculation of multiplying a first constant (α) by a maximum value of the pressure pulse wave amplitude and adding a third constant (ζ, ζtsys) related to a component of a background pulse wave generated when the pressure in the cuff (2101) is pressurized to a predetermined pressure outside a predetermined measurement range for the blood pressure value, and to calculate a calculation parameter for the diastolic blood pressure based on a predetermined calculation of multiplying a second constant (β) by a maximum value of the pressure pulse wave amplitude and adding a fourth constant (η, ηtdia) related to a component of a background pulse wave; and the correction means corrects the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the information related to the measurement state.

Description

TECHNICAL FIELD

[0001] The present invention relates to an electronic blood pressure monitor and a blood pressure measuring method. BACKGROUND OF THE INVENTION

[0002] Blood pressure is a type of indicator for diagnosing cardiovascular disease. Risk assessment based on blood pressure is effective in preventing cardiovascular diseases such as stroke, cardiac arrest, and heart attack. Typically, a diagnosis for risk assessment is based on blood pressure (casual blood pressure) measured in medical facilities during hospital visits and checkups. However, recent research has shown that blood pressure measured at home is more effective in diagnosing cardiovascular disease than casual blood pressure. Accompanying this, home blood pressure monitors are widely used.

[0003] Most commonly used electronic blood pressure monitors currently use the oscillometric method for calculating blood pressure. In the oscillometric method, a cuff is wrapped around a measurement site, such as the upper arm, and pressurized to a predetermined pressure, then gradually or stepwise released. The oscillometric method is a method of detecting a change in arterial volume, which occurs at the midpoint of pressure release as a pressure change (pressure pulse wave amplitude) superimposed on the cuff pressure, and applying a predetermined algorithm to the change in pressure pulse wave amplitude to determine the systolic blood pressure and diastolic blood pressure.Generally, a point at which the pressure pulse wave amplitude suddenly becomes large during pressure release is considered to be close to the systolic blood pressure, and a point at which the pressure pulse wave amplitude suddenly becomes low is considered to be close to the diastolic blood pressure. Various algorithms have been tested to detect such points.

[0004] For example in Fig. 9 and the following [Equation 1], a value obtained by multiplying a predetermined index (first constant α, second constant β) previously set by a maximum value of the pressure pulse wave amplitude is set as a calculation parameter for the blood pressure, and a cuff pressure at which the pressure pulse wave amplitude that agrees with (or is closest to) the relevant parameter is obtained is calculated as the blood pressure value (refer to Patent Document 1). [Equation 1] Calculation parameters for systolic blood pressure = maximum value of the pressure pulse wave amplitude × α Calculation parameters for diastolic blood pressure = maximum value of the pressure pulse wave amplitude × β

[0005] Patent Document 1: Japanese Unexamined Patent Application Laid-Open No. 3-81375 DISCLOSURE OF THE INVENTION PROBLEMS SOLVED BY THE INVENTION

[0006] However, there is no theoretical proof that the point at which the pressure pulse wave amplitude suddenly changes coincides with the systolic blood pressure and the diastolic blood pressure. Therefore, the first and second constants (α, β) for determining the blood pressure calculation parameter had to be determined experimentally or statistically based on a change pattern (hereinafter referred to as the "envelope") from a large number of blood pressure values ​​and pressure pulse wave amplitudes. Typically, the first constant α is a fixed value of approximately 0.5, and the second constant β is a fixed value of approximately 0.7, regardless of the user's condition and / or the condition of the cuff at the time of blood pressure measurement.

[0007] A pressure pulse wave amplitude forming the envelope has the following problems. First, the pressure pulse wave amplitude is detected by detecting a volume change of an artery, which is transmitted to the cuff attached to the measuring site as the pressure change. The pressure pulse wave amplitude is thus subject to the influence of the cuff's properties. One of the cuff's properties is an air flow rate (hereinafter referred to as "cuff compliance"), which is necessary to change the pressure in the cuff (hereinafter referred to as "cuff pressure") by 1 mmHg, as shown in the graph of Fig. 10. As shown in Fig. As shown in Figure 10, the cuff's compliance decreases as the cuff pressure increases. Therefore, the amplitude is detected as large as the cuff pressure increases if a constant pressure pulse wave amplitude is provided to the cuff without depending on the cuff pressure, as shown in Fig. 11 shown.

[0008] For example, when measuring two users with different blood pressures, with a change in the pressure pulse wave amplitude from the same envelope shape, the pressure pulse wave amplitude, i.e., the shape of the envelope detected by the blood pressure monitor, will differ depending on the blood pressure. Thus, there is a difference in measurement accuracy depending on the blood pressure.

[0009] A state in which an artery B of an arm A of a user is compressed with a cuff 2101 will be described with reference to Fig. 12. As described in Fig. 12, the pressure of the central portion of the cuff 2101 is sufficiently transmitted to the artery B so that the artery B is completely pressure-closed when the cuff pressure is pressurized to be greater than or equal to a predetermined pressure of a blood pressure measurement range.

[0010] However, artery B is not completely pressure-sealed because the pressure at the end of the cuff 2101 is not fully transmitted to artery B. This depends on the structure of the cuff 2101, in which the portion where artery B is not pressure-sealed always forms in the generally used cuff structure. There is blood flow in a portion where the artery is not pressure-sealed, corresponding to the cardiac side of the cuff 2101, and thus the volume change of artery B occurs, and the resulting pressure pulse wave is detected. In Patent Document 1, such a pressure pulse wave is referred to as the background pulse wave. Due to the existence of the background pulse wave, the systolic blood pressure is detected as too high, and the diastolic blood pressure is perceived as underestimated in [Equation 1].

[0011] In the conventional manner disclosed in Patent Document 1, [Equation 1] is changed to the following [Equation 2]. A shift correction value (third constant ζ) indicating the background pulse wave component is added to the value obtained by multiplying a predetermined index (first constant α) set in advance by a maximum value of the pressure pulse wave amplitude to calculate the systolic blood pressure calculation parameter, and a shift correction value (fourth constant η) indicating the background pulse wave component is added to the value obtained by multiplying a predetermined index (second constant β) set in advance by a maximum value of the pressure pulse wave amplitude to calculate the diastolic blood pressure calculation parameter. [Equation 2] Calculation parameters for systolic blood pressure = maximum value of the pressure pulse wave amplitude × α + ξ Calculation parameters for diastolic blood pressure = maximum value of the pressure pulse wave amplitude × β + η

[0012] [Equation 2] is based on the assumption that the background pulse wave is constant without depending on the nature of the user and / or the condition of the cuff 2101 at the time of blood pressure measurement, such as the attributes of the user (circumferential length, blood pressure of arm A), the size or cuff pressure of the cuff 2101, and the like.

[0013] However, it is recognized that the background pulse wave varies within different conditions at the time of blood pressure measurement. If the cuff pressure at the time of

[0014] Example is increased, then a width at which the artery B is pressure-closed becomes wider, as in Fig. 12. This is accompanied by a narrower width on which the background pulse wave arises when the artery B is not pressure-closed, whereby the level of the background pulse wave, which is detected as a result, becomes low, as in the graph of Fig. 13 shown.

[0015] The pressure pulse wave amplitude changes depending on the dynamic properties (arterial volume change, which is involved in the pressure difference in the artery between inside and outside) of the user's artery B. For example, a person with a soft artery B has a large amplitude, whereas a person with advanced arteriosclerosis has a small amplitude (see Fig. 14). For this reason, the background pulse wave also changes depending on the dynamic properties.

[0016] If the systolic blood pressure and the diastolic blood pressure are set by [Equation 2], in which the component of the background pulse wave is set as constant, then the blood pressure will be underestimated or set as too high, depending on the user.

[0017] In view of the problems described above, it is an object of the present invention to provide an electronic sphygmomanometer and a blood pressure measurement method for correcting a constant based on information related to the measurement state when performing a predetermined operation using the constant which is previously set in view of the change in a pressure pulse wave amplitude indicative of the volume change of the artery at the time of blood pressure measurement, to accurately detect the blood pressure value using the detected data and thereby increase the level of user satisfaction.

[0018] Furthermore, US 2003 / 0 097 074 A1 discloses a blood pressure monitor comprising a cuff, means for pressurizing and depressurizing the cuff, pressure detection means, and blood pressure calculation means. The blood pressure calculation means is intended to be able to determine a calculation parameter for the blood pressure using a constant representing a pressure pulse wave amplitude. MEANS TO SOLVE THE PROBLEM

[0019] The present invention provides an electronic blood pressure monitor having the features of claim 1 and a method for measuring blood pressure having the features of claim 12.

[0020] The measurement condition-related information related to the user's condition may include information related to the user's blood pressure value at the time of measurement, the maximum value of the pressure pulse wave amplitude, information related to the measurement site, information about the user's diseases, and information about the user's age.

[0021] The measurement condition-related information related to the condition of the cuff may include information on the specification of the cuff, such as a size and a type of cuff, in addition to the maximum value of the cuff pressure at the time of blood pressure measurement and the wrapping strength of the cuff.

[0022] According to the present invention, an optimal calculation parameter for blood pressure can be set for each condition of the user and / or the condition of the cuff at the time of blood pressure measurement, and the measurement error can be reduced.

[0023] The temporarily set blood pressure value may be temporarily set during depressurization by a standard blood pressure calculation parameter. The temporarily set blood pressure value may be temporarily set during pressurization by a standard blood pressure calculation parameter. The temporarily set blood pressure value may be the blood pressure value recorded in the recording means. According to the present invention, the optimal blood pressure calculation parameter can be set for each user's blood pressure value, and the measurement error can be reduced.

[0024] In the present invention, the blood pressure calculation means has a configuration configured to calculate a calculation parameter for systolic blood pressure based on a predetermined calculation of multiplying a first constant by a maximum value of the pressure pulse wave amplitude and adding a third constant related to a component of a background pulse wave generated when the pressure in the cuff is pressurized to a predetermined pressure outside a predetermined blood pressure value measurement range, and to calculate a calculation parameter for diastolic blood pressure based on a predetermined calculation of multiplying a second constant by a maximum value of the pressure pulse wave amplitude and adding a fourth constant related to a component of a background pulse wave;and the correction means corrects the third and fourth constants based on the information related to the measurement state.;

[0025] According to the present invention, the third and fourth constants related to the background pulse wave component can be corrected for each condition of the user and / or the condition of the cuff at the time of blood pressure measurement, so that an accurate blood pressure measurement value can be calculated while suppressing the influence of error caused by the background pulse wave component.

[0026] In the present invention, the information acquiring means may have a configuration configured to acquire information on a temporarily set blood pressure value as the measurement condition-related information related to the user's condition; and the correcting means may have a configuration configured to correct the first and second constants or the third and fourth constants based on the temporarily set blood pressure value.

[0027] Furthermore, in the present invention, the information acquiring means may have a configuration configured to acquire information on a maximum value of the cuff pressure as the measurement state-related information; and the correcting means may have a configuration configured to correct the first and second constants or the third and fourth constants based on the maximum value of the cuff pressure.

[0028] In the present invention, the information acquiring means may have a configuration configured to acquire information on a maximum value of the pressure pulse wave amplitude as the measurement condition-related information related to the condition of the user; and the correcting means may have a configuration configured to correct the third and fourth constants based on the maximum value of the pressure pulse wave amplitude.

[0029] Furthermore, in the present invention, the information acquiring means may have a configuration configured to acquire information on a maximum value of the cuff pressure as the measurement state-related information; and the correcting means may have a configuration configured to correct the first and second constants or the third and fourth constants based on the maximum value of the cuff pressure.

[0030] In the present invention, the information acquiring means may have a configuration configured to acquire information on a maximum value of the pressure pulse wave amplitude as the measurement condition-related information related to the condition of the user; and the correcting means may have a configuration configured to correct the third and fourth constants based on the maximum value of the pressure pulse wave amplitude.

[0031] In the present invention, the information acquiring means may have a configuration configured to acquire information on a wrapping thickness of the cuff as the measurement state-related information; and the correcting means may have a configuration configured to correct the third and fourth constants based on the information on the wrapping thickness of the cuff.

[0032] In the present invention, the information acquiring means may have a configuration configured to acquire cuff specification information related to a size and / or a type of the cuff as the measurement condition-related information; and the correcting means may have a configuration configured to correct the third and fourth constants based on the cuff specification information.

[0033] In the present invention, the information acquiring means may have a configuration configured to acquire information related to a user's measurement location as the measurement state-related information; and the correcting means may have a configuration configured to correct the third and fourth constants based on the information related to the user's measurement location.

[0034] The information related to the user's measuring point may include information such as the circumference and the condition of the measuring point.

[0035] The nature of the measurement site may include percentage of body fat, percentage of subcutaneous fat, or BMI.

[0036] In the present invention, the information acquiring means may have a configuration configured to acquire information on diseases of the user as the information related to the measurement condition; and the correcting means may have a configuration configured to correct the third and fourth constants based on the information on diseases of the user.

[0037] In the present invention, the information acquiring means may have a configuration configured to acquire age information of the user as the information related to the measurement condition; and the correcting means may have a configuration configured to correct the third and fourth constants based on the age information of the user.

[0038] In the present invention, the information detecting means may have a configuration configured to detect the information related to the measurement state based on a change in the internal pressure of the cuff.

[0039] In the present invention, input means for allowing the user to input the information related to the measurement state may also be provided; wherein the information acquisition means may have a configuration configured to acquire the information related to the measurement state input before the start of the blood pressure measurement.

[0040] In the present invention, the step of calculating the calculation parameter for blood pressure by the blood pressure calculating means comprises calculating a calculation parameter for systolic blood pressure based on a predetermined calculation of multiplying a first constant by a maximum value of the pressure pulse wave amplitude and adding a third constant related to a component of a background pulse wave, and calculating a calculation parameter for diastolic blood pressure based on a predetermined calculation of multiplying a second constant by a maximum value of the pressure pulse wave amplitude and adding a fourth constant related to a component of a background pulse wave; and the step of correcting by the correcting means comprises correcting the third and fourth constants based on the information related to the measurement state.

[0041] According to the present invention, the third and fourth constants related to the background pulse wave component are corrected for each condition of the user and / or the condition of the cuff at the time of blood pressure measurement, so that a process of calculating an accurate blood pressure value is carried out while suppressing the influence of error caused by the background pulse wave component. EFFECT OF THE INVENTION

[0042] According to the present invention, an electronic blood pressure monitor and the blood pressure measurement method for accurately detecting the blood pressure value using the detected data are provided, so that the user's satisfaction level can be improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a configuration of an electronic blood pressure monitor of an embodiment. Fig. 2 is a flowchart showing a blood pressure measuring operation not falling within the scope of the present invention. Fig. Figure 3 is a table showing a key figure for setting the blood pressure calculation parameters for a standard and for each temporary average blood pressure value. Fig. 4 is a flowchart showing another example of a measuring operation not falling within the scope of the present invention. Fig. 5 is a flowchart showing another example of a blood pressure measuring operation not falling within the scope of the present invention. Fig. 6 is a flowchart showing a blood pressure measurement operation according to an embodiment. Fig. 7 is a view showing a state where an artery of an arm of a user is compressed with a cuff, and a view describing a relationship between a background pulse wave and a circumferential length of the measurement site of the user. Fig. 8 is a view showing a state where an artery of an arm of a user is compressed with a cuff, and a view describing a relationship between a background pulse wave and the size of the cuff. Fig. Figure 9 is a diagram describing an example of a blood pressure calculation algorithm of an oscillometric type blood pressure monitor. Fig. Figure 10 is a diagram showing an example of a property (cuff compliance) of the cuff. Fig. 11 is a graph showing an example of a pressure pulse wave amplitude detected by the blood pressure monitor when a constant pulse wave amplitude is input. Fig. Fig. 12 is a view showing a state where the artery of the user's arm is compressed with the cuff, and a view describing the relationship of the background pulse wave and the blood pressure value. Fig. Figure 13 is a graph showing characteristics of the background pulse wave amplitude. Fig. Figure 14 is a graph showing an example of dynamic properties of the artery. DESCRIPTION OF EMBODIMENTS

[0043] An embodiment of the present invention will be described below with reference to the drawings. First embodiment

[0044] First, a first embodiment will be described in which a blood pressure calculation parameter is optimized for each blood pressure value of a user. As shown in Fig. 1, an electronic blood pressure monitor 2100 of a first embodiment includes a cuff 2101, an air tube 2102, a pressure sensor 2103, a pump 2104, a valve 2105, an oscillation circuit 2111, a pump control circuit 2112, a valve control circuit 2113, a timing control unit 2115, a power supply unit 2116, a CPU 2120, a display unit 2121, a memory (for processing) 2122, a memory (for recording) 2123, an operation unit 2130, an interface 2171, and an external memory 2172. Fig. 1 is a block diagram showing a configuration of the electronic blood pressure monitor 2100 of the first embodiment.

[0045] The cuff 2101 is a band-shaped member connected to the air tube 2102 and attached to a user's blood pressure measuring site for applying air pressure.

[0046] The 2103 pressure sensor is an electrostatic capacitive pressure sensor in which a capacitance value changes according to the pressure in the cuff (cuff pressure).

[0047] Pump 2104 and valve 2105 apply pressure to the cuff and adjust (control) the pressure in the cuff. Oscillating circuit 2111 outputs a signal with a frequency corresponding to the capacitance value of pressure sensor 2103. Pump control circuit 2112 and valve control circuit 2113 drive pump 2104 and valve 2105, respectively.

[0048] The timing unit 2115 is a device for timing the current date and time and transmits the time-controlled date and time to the central unit 2120 as required. The power supply unit 2116 provides electrical power to each configuration unit.

[0049] The central unit 2120 carries out the control of the pump 2104, the valve 2105, the display unit 2121, the memories 2122, 2123, the operation unit 2130 and the interface 2171, the setting process for the blood pressure and the management of the recorded values.

[0050] The display unit 2121 is constituted by a display device such as a liquid crystal display and displays the blood pressure value according to a signal transmitted from the central unit 2120.

[0051] The memory (for processing) 2122 stores an index (to be described later) for setting the calculation parameter for blood pressure and a control program of the blood pressure monitor.

[0052] The memory (for recording) 2123 stores the blood pressure value and it stores the date and time, the user, and the measured values ​​in linkage with each other, if necessary.

[0053] The operation unit 2130 is composed of a power switch 2131, a measurement switch 2132, a stop switch 2133, a data output switch 2141, and a user selection switch 2142, and enables operation input such as turning the blood pressure monitor on / off and starting the measurement, and transmits the input signal to the central unit 2120. The interface 2171 records / reads / out the blood pressure to and from the external memory 2172 under the control of the central unit 2120.

[0054] The blood pressure measuring operation using the blood pressure monitor 2100 configured as described above is carried out in accordance with the flowchart of Fig. 2 are described. Fig. 2 is a flowchart showing the blood pressure measuring operation in the first embodiment.

[0055] First, when the power supply is turned ON by operating the power switch 2131 (power switch) (step S2101), the central unit 2120 executes the initialization process of the operation memory of the blood pressure monitor and performs 0 mmHg setting of the pressure sensor 2103 (step S2102).

[0056] After the initialization process is completed, the cuff 2101 is wrapped around the user's measurement site, the user is selected (step S2103), and the measurement switch 2132 (measurement switch) is pressed (step S2104), so that the central unit 2120 pressurizes the cuff to a predetermined pressure through the pump 2104 (steps S2105 to S2106), and gradually releases the cuff pressure through the valve 2105 (step S2107). After the temporary blood pressure value is calculated (step S2109), the central unit 2120 opens the valve 2105 and releases the air in the cuff. The central unit 2120 optimizes the blood pressure calculation parameter using the calculated temporary blood pressure value (step S2110), and calculates the blood pressure value using the optimized blood pressure calculation parameter (step S2111).The central unit 2120 displays the calculated blood pressure value on the display unit 2121 (step S2112) and records the same in the memory (for recording) 2123 in association with the measurement date and time and the user (step S2113).

[0057] The process from steps S2105 to S2111 will be described in more detail by focusing on the optimization process (step 2110) of the calculation parameter for blood pressure. As shown in the table of Fig. 3, the memory records (for processing) the indicators α, β for setting the blood pressure calculation parameter (systolic blood pressure calculation parameter and diastolic blood pressure calculation parameter) for the standard and each temporary blood pressure value. Fig. Figure 3 is a table showing the indices (α, β) for setting the calculation parameters for blood pressure, which are classified according to the standard and temporary average blood pressure values.

[0058] The central unit 2120 for executing step S2108 in Fig. 2. Calculates the temporary systolic blood pressure calculation parameter and the temporary diastolic blood pressure calculation parameter by multiplying the α and β (first and second constants) for setting the standard blood pressure calculation parameter by the maximum pressure pulse wave amplitude, thereby calculating the temporary blood pressure value (temporary diastolic blood pressure, temporary systolic blood pressure). The α (first constant) for setting the systolic blood pressure calculation parameter is set to 0.5 (50%), and the β (second constant) for setting the diastolic blood pressure calculation parameter is set to 0.7 (70%).After the temporary calculation parameter for the systolic blood pressure and the temporary calculation parameter for the diastolic blood pressure are calculated, the central unit 2120 calculates the temporary average blood pressure value with the following equation. Temporary mean blood pressure = temporary diastolic blood pressure + (temporary systolic blood pressure - temporary diastolic blood pressure) / 3

[0059] After executing steps S2109 to S2110, the central unit 2120 sets the indexes α, β for setting the calculation parameters for the blood pressure according to the temporary average blood pressure value based on Fig. 3, sets the blood pressure calculation parameter obtained by multiplying the indexes α, β by the maximum value of the pressure pulse wave amplitude as the optimized blood pressure calculation parameter, and uses the optimized blood pressure calculation parameter to execute the blood pressure calculation again in step S2111.

[0060] In the present embodiment, the temporary average blood pressure value is divided into a plurality of (for example, three) sections for each predetermined range, and the index α for setting the calculation parameter for the systolic blood pressure and the index β for setting the calculation parameter for the diastolic blood pressure are previously set for each section.

[0061] For the α index, the segment below 100 mmHg is the largest, or 55%, and the α index decreases as the temporary average blood pressure value increases. For example, it is smallest, or 45%, in the segment greater than or equal to 150 mmHg.

[0062] On the other hand, for the β index, the segment whose value is less than 100 mmHg is the smallest, or 60%, and the β index increases as the temporary average blood pressure value increases. For example, it is the largest, or 80%, in the segment that is greater than or equal to 150 mmHg.

[0063] As described above, the indicators α and β are classified based on the temporary average blood pressure value, but they can also be classified based on any one of the temporary systolic blood pressure value and the temporary diastolic blood pressure value, or two or more of the multiple blood pressure values. Furthermore, the indicators can be classified based on the cuff pressure at which the pulse wave amplitude reaches a maximum value.

[0064] Furthermore, the calculation parameter for blood pressure can be calculated with the following equation using any one of the temporary systolic blood pressure, the temporary diastolic blood pressure, the temporary average blood pressure, and the cuff pressure at which the maximum value of the pulse wave amplitude is reached. [Equation 4] Calculation parameters for systolic blood pressure P_SBP=ψ×P2+ω×P+ε Calculation parameters for diastolic blood pressure P_DBP=δ×P2+π×P+ρ

[0065] Here, P denotes any one of the temporary systolic blood pressure, the temporary diastolic blood pressure, the temporary average blood pressure and the cuff pressure at which the maximum value of the pulse wave amplitude is reached, and ψ, ω, ε, δ, π, ρ each denotes a predetermined coefficient which is determined by the followability of the cuff.

[0066] An embodiment in which the temporary set blood pressure value is temporarily set during pressurization from the standard calculation parameter for blood pressure is described according to a flowchart of Fig. 4 can be described as another example of the blood pressure measurement operation. Fig. Fig. 4 is a flowchart showing an example of the blood pressure measurement operation in the first embodiment. In each embodiment described below, the calculation in the central unit 2120 mainly differs, but the hardware configuration of the electronic blood pressure monitor 2100 is substantially similar to the embodiment described above, and thus the configuration of each unit is indicated using the reference numerals of Fig. 1 are described.

[0067] First, the central processing unit 2120 initializes the processing memory of the sphygmomanometer when the power switch 2131 of the sphygmomanometer is pressed (step S2121) and sets the pressure sensor 2103 to 0 mmHg (step S2122). The user whose blood pressure is to be measured is then selected (step S2123), and the measurement switch 2132 is pressed (step S2124), so that the central processing unit 2120 gradually pressurizes the cuff pressure with the pump 2104 (step S2125). The central processing unit 2120 extracts the pressure change component involved in the volume change of the artery superimposed on the cuff pressure obtained during pressurization and calculates the temporary blood pressure value by a predetermined calculation (step S2126).After applying pressure to a predetermined pressure (step S2127), the central unit 2120 optimizes the blood pressure calculation parameter with the temporary blood pressure value calculated during the pressurization (step S2128).

[0068] The central unit 2120 then gradually releases the cuff pressure using the valve 2105 (step S2129). The central unit 2120 extracts the pressure change component involved in the volume change in the artery superimposed on the cuff pressure obtained during pressure release and calculates the blood pressure value by a predetermined calculation using the optimized blood pressure calculation parameter (step S2130). After calculating the blood pressure value (step S2131), the central unit 2120 opens the valve 2105 to release air from the cuff. The central unit 2120 displays the calculated blood pressure value on the display unit 2121 (step S2132) and records it in the memory (for recording) 2123 in association with the measurement date and time and the user (step S2133).The optimization process of the blood pressure calculation parameter is a process similar to the one described above, and therefore its description is not reproduced.

[0069] An embodiment in which the temporarily set blood pressure value is the blood pressure value recorded in the memory (for recording) 2123 will now be described according to a flowchart of Fig. 5 can be described as another example of the blood pressure measurement operation. Fig. 5 is a flowchart showing an example of the blood pressure measurement operation in the first embodiment.

[0070] When the power switch 2131 of the blood pressure monitor is pressed (step S2141), the central unit 2120 initializes the processing memory of the blood pressure monitor and performs a 0 mmHg setting of the pressure sensor 2103 (step S2142).

[0071] The user whose blood pressure is to be measured is then selected (step S2143), and the measurement switch 2132 is pressed (step S2144), so that the central unit 2120 reads the instantaneous recorded value of the selected user from the memory (for recording) 2123 (step S2145) and optimizes the calculation parameter for blood pressure based on such recorded value (step S2146). The central unit 2120 then gradually pressurizes the cuff pressure with the pump 2104 (step S2147). After pressurizing to a predetermined pressure (step S2148), the central unit 2120 then gradually releases the cuff pressure with the valve 2105 (step S2149).

[0072] The central unit 2120 extracts the pressure change component involved in the volume change of the artery superimposed on the cuff pressure obtained during pressure release and calculates the blood pressure value by a predetermined calculation using the optimized blood pressure calculation parameter (step S2150). After calculating the blood pressure value (step S2151: YES), the central unit 2120 opens the valve 2105 to deflate the cuff. The central unit 2120 displays the calculated blood pressure value on the display unit 2121 (step S2152) and records it in the memory (for recording) 2123 in association with the measurement date and time and the user (step S2153).

[0073] The optimization process of the calculation parameter for blood pressure is the process which is similar to the process described above, and therefore its description is not reproduced.

[0074] The recorded value used to optimize the blood pressure calculation parameter may be an average value or a representative value of two or more instantaneous recorded values. The recorded value may use a value recorded in an external recording medium (external storage 2172, such as a USB memory), a personal computer, or a server via the Internet.

[0075] As described above, an electronic blood pressure monitor 2100 is provided, which includes biological information acquisition means for measuring a blood pressure value, recording means (memory 2123) for recording the blood pressure value, means (memory 2122) for storing an index for predetermined calculation parameters for blood pressure and a control program of a blood pressure monitor, operating means (operation unit 2130) for performing operations such as blood pressure measurement, correcting means (central processing unit 2120) for correcting the blood value acquired by the biological information acquisition means based on measurement condition information related to the condition of the user and / or the condition of the cuff 2101 at the time of blood pressure measurement, and outputting means (display unit 2121) for outputting the corrected information (blood pressure value) after the correction.and the biological information acquisition means comprises a cuff 2101 attached to a blood pressure measurement site, pressurization and depressurization means 2104, 2105 for adjusting the pressure applied to the cuff 2101, pressure detection means (pressure sensor 2103) for detecting a pressure in the cuff, and blood pressure calculation means (central unit 2120) for calculating a blood pressure value from the cuff pressure, wherein the blood pressure calculation means (central unit 2120) is configured to calculate the blood pressure calculation parameter based on a predetermined calculation of multiplying a characteristic number α serving as a first constant and a characteristic number β serving as a second constant, which are previously set with respect to a maximum value (change) of a pressure pulse wave amplitude,which characterizes a volume change of an artery at the time of blood pressure measurement; and comprises information acquisition means (central unit 2120 for executing steps S2108, S2126, S2145) for acquiring information from the temporarily set blood pressure value for the user's measurement state-related information; and the correction means (central unit 2120 for executing steps S2110, S2128, S2146) is configured to correct the blood pressure calculation parameter by correcting the indexes α, β based on the temporarily set blood pressure value.

[0076] According to the configuration described above, an optimal blood pressure calculation parameter is set for each user's blood pressure value, and the measurement error can be reduced while suppressing the error influence caused by the background pulse wave component. Second embodiment

[0077] A second embodiment in which a shift correction value (third and fourth constants) related to a component of the background pulse wave is corrected from the measurement condition related information for reducing the measurement error, which is related to the condition of the user and / or the condition of the cuff 2101 at the time of blood pressure measurement, is carried out according to a flowchart of Fig. 6 are described. Fig. 6 is a flowchart showing an example of the blood pressure measuring operation in the second embodiment.

[0078] First, the central unit 2120 initializes the processing of the blood pressure monitor when the power switch 2131 of the blood pressure monitor is pressed (step S2161) and sets the pressure sensor 2103 to 0 mmHg (step S2162). The user whose blood pressure is to be measured is then selected (step S2163), and the measurement switch 2132 is pressed (step S2164), so that the central unit 2120 gradually pressurizes the cuff pressure with the pump 2104 (steps S2165 to S2166) and gradually releases the cuff pressure with the valve 2105 (step S2167).

[0079] The central unit 2120 extracts the pressure change component involved in the volume change of the artery superimposed on the cuff pressure obtained during pressure release, and calculates the temporary systolic blood pressure value and the temporary diastolic blood pressure value by a predetermined calculation shown in the following [Equation 5] (step S2168). [Equation 5] T_AmpSys=Maximum value of the pressure pulse wave amplitude×α+ξtsys T_AmpDia=Maximum value of the pressure pulse wave amplitude×β+ηtdia

[0080] Here, T_AmpSys in [Equation 5] is the temporary calculation parameter for systolic blood pressure, and T_AmpDia is the temporary calculation parameter for diastolic blood pressure. Furthermore, ζtsys and ηtdia are shift correction values ​​(third and fourth constants) related to the background pulse wave component generated when the pressure in the cuff 2101 is applied to a predetermined pressure outside the blood pressure measurement range, and these are values ​​previously determined through an experiment.

[0081] The central unit 2120 sets the cuff pressure at a point where T_AmpSys calculated in step S2168 meets the Fig. 9, as the temporary systolic blood pressure value, and the cuff pressure at a point where T_AmpDia, which was calculated in step S2168, intersects the Fig. 9, as the temporary diastolic blood pressure value.

[0082] The central unit 2120 then corrects the shift correction value ζ (third constant) and the shift correction value η (fourth constant) related to the background pulse wave component in [Equation 5] with the temporary systolic blood pressure value and the temporary diastolic blood pressure value set in step S2168. As in Fig. 13, the component of the background pulse wave becomes smaller as the cuff pressure becomes larger, so the shift correction value is corrected by a predetermined calculation shown in the following [Equation 6] (step S2168). [Equation 6] ξ=ξtsys+temporary systolic blood pressure value×θ η=ηtdia temporary diastolic blood pressure value×τ

[0083] Here, θ and τ in [Equation 6] are values ​​previously determined by experiment.

[0084] The central unit 2120 calculates the systolic blood pressure calculation parameter and the diastolic blood pressure calculation parameter by a predetermined calculation shown in the following [Equation 7], in which ζ, η, which were corrected in step S2169, are replaced by ζtsys, ηtdia of [Equation 5], and optimizes the same in (step S2170). [Equation 7] Calculation parameters for systolic blood pressure = maximum value of the pressure pulse wave amplitude × α + ξ Calculation parameters for diastolic blood pressure = maximum value of the pressure pulse wave amplitude × β + η

[0085] Similar to the case of the temporary systolic blood pressure value and the temporary diastolic blood pressure value, the central unit 2120 sets the cuff pressure at a point where the systolic blood pressure calculation parameter and the diastolic blood pressure calculation parameter calculated in step S2170 intersect the envelope curve as the systolic blood pressure value and the diastolic blood pressure value (step S2171).

[0086] The central unit 2120 displays the calculated blood pressure value on the display unit 2121 (step S2172) and records the same in the memory (for recording) 2123 in association with the measurement date and time and the user (step S2173).

[0087] As described above, an electronic sphygmomanometer 2100 is provided, which comprises biological information acquisition means for measuring a blood pressure value, recording means (memory 2123) for recording the blood pressure value, means (memory 2122) for storing a control program of a sphygmomanometer, operating means (operation unit 2130) for performing operations such as blood pressure measurement, correcting means (central processing unit 2120) for correcting the blood value based on a component of the background pulse wave generated when the pressure of a cuff 2101 is pressurized to a predetermined pressure outside a measuring range for the blood pressure value, and outputting means (display unit 2121) for outputting the corrected information (blood pressure value) after the correction, and the biological information acquisition means comprises a cuff 2101,which is attached to a blood pressure measurement site, pressurization and depressurization means 2104, 2105 for adjusting the pressure applied to the cuff 2101, pressure detection means (pressure sensor 2103) for detecting a pressure in the cuff, and blood pressure calculation means (central unit 2120) for calculating the blood pressure value from the cuff pressure; wherein the blood pressure calculation means (central unit 2120) is configured to multiply an index α serving as a first constant, which has been set in advance, with respect to a maximum value (change) of a pressure pulse wave amplitude indicative of a volume change of an artery at the time of blood pressure measurement, and calculates a calculation parameter for the systolic blood pressure based on a predetermined calculation of adding a shift correction value ζ serving as a third constant,which is related to the component of the background pulse wave, and further multiplies a characteristic β, which serves as a second constant, which is previously set, with respect to a maximum value (change) of the pressure pulse wave amplitude; and comprises information acquiring means (CPU 2120, which executes step S2168) for acquiring information of a temporary systolic blood pressure value and a temporary diastolic blood pressure value as the measurement condition-related information related to the condition of the user at the time of blood pressure measurement; and the correcting means (CPU 2120, which executes step S2169) is configured to correct the blood pressure calculation parameters by correcting the blood pressure value shift correction values ​​ζ, η based on the information of the temporary systolic blood pressure value and the temporary diastolic blood pressure value.

[0088] According to the configuration described above, the shift correction values ​​ζ, η related to the component of the background pulse wave can be corrected for each condition (blood pressure value of the user in the present embodiment) of the user at the time of blood pressure measurement, so that an accurate blood pressure value can be calculated while suppressing the influence of error caused by the component of the background pulse wave.

[0089] In the above description, the shift correction values ​​(third and fourth constants) are set by multiplying a predetermined number with respect to the temporary systolic blood pressure value and the temporary diastolic blood pressure value, but a setting table for the shift correction value (for setting the third and fourth constants) corresponding to the temporary systolic blood pressure value and the temporary diastolic blood pressure value may be stored in the memory 2123 of the electronic sphygmomanometer 2100, and the shift correction values ​​(third and fourth constants) may be read from the table.

[0090] An embodiment of correcting the shift correction values ​​based on the maximum value of the cuff pressure will now be described as another example of the blood pressure measuring operation.

[0091] Typically, the blood pressure value determination method of an oscillometric method includes the following. First, there is a method (hereinafter referred to as the pressure release measurement method) of determining the blood pressure value during cuff pressure release. In the pressure release measurement method, the cuff is pressurized to a pressure higher than a predetermined pressure, and a point at which the pressure pulse wave amplitude rapidly increases while the cuff pressure is gradually released is set as the systolic blood pressure value, and a point at which the pressure pulse wave rapidly decreases while the cuff pressure is further gradually released is set as the diastolic blood pressure value.There is also a method (hereinafter referred to as pressurization measurement method) of setting the blood pressure value while pressurizing the cuff 2101, in the pressurization measurement method, the cuff is gradually pressurized and a point at which the pressure pulse wave amplitude rapidly increases in the process is set as the diastolic blood pressure value, and a point at which the pressure pulse wave rapidly decreases while the cuff pressure is gradually released is set as the systolic blood pressure value.

[0092] In the case of the depressurization measurement method, the cuff pressure is pressurized to a pressure higher than the measurement range by a predetermined pressure (for example, 30 mmHg), at which pressure value is defined as a maximum cuff pressure value Pcmax in the present embodiment. In the blood pressure measuring device of the pressurization measurement method, pressurization is performed until the pressure pulse wave amplitude information necessary for setting the systolic blood pressure value is detected, while the cuff pressure is gradually pressurized. After the systolic blood pressure value is set, pressurization is stopped, and the cuff pressure is quickly released with the valve 2105, wherein the cuff pressure immediately before the start of depressurization is defined as a maximum cuff pressure value Pcmax in the present embodiment.

[0093] In the present embodiment, the central processing unit 2120 corrects the shift correction values ​​ζ, η, which characterize the component of the background pulse wave, by means of a predetermined calculation shown in the following [Equation 8], based on the value Pcmax. In the present embodiment, the shift correction values ​​ζ, η are corrected using the shift correction values ​​ζtsys, ηtdia shown in [Equation 5], as shown in the following [Equation 8]. [Equation 8] ξ=ξtsys+Pcmax×κ η=ηtdia+Pcmax×λ

[0094] Here, in [Equation 8], ĸ and λ are values ​​previously determined through experiment. In the present embodiment, the displacement correction values ​​ζ, η corrected with [Equation 8] are applied to [Equation 7], similar to the one in Fig. 6 to calculate and optimize the systolic blood pressure calculation parameter and the diastolic blood pressure calculation parameter, thereby setting the blood pressure value.

[0095] In the present embodiment, the shift correction value setting table (setting of the third and fourth constants) in which the shift correction value and the value of Pcmax are related to each other may be previously recorded in the memory 2123 of the electronic sphygmomanometer 2100, and the shift correction values ​​(third and fourth constants) may be read out from the table.

[0096] For this reason, an accurate blood pressure value can be calculated while suppressing the influence of error caused by the difference in the maximum value Pcmax of the cuff pressure by correcting the shift correction values ​​ζ, η based on the information of the maximum value Pcmax of the cuff pressure.

[0097] An embodiment of correcting the shift correction value based on the maximum value of the pressure pulse wave amplitude will now be described as another example of the blood pressure measurement operation. In the present embodiment, the cuff pressure at a point where the pressure pulse wave amplitude reaches a maximum (AmpMax) is measured as Pcamp in the Fig. 9. The central unit 2120 corrects the shift correction values ​​ζ, η, which characterize the component of the background pulse wave, according to a predetermined calculation based on the value Pcamp, which is shown in the following [Equation 9]. [Equation 9] ξ=ξtsys+Pcamp×μ η=ηtdia+Pcamp×v

[0098] Here, µ and v in [Equation 7] are values ​​previously determined through experimentation. The optimization process for the blood pressure calculation parameters in this process is similar to the one described above, and therefore its description is not reproduced.

[0099] In the present embodiment, the shift correction value setting table (setting of the third and fourth constants) in which the shift correction value and the value of Pcamp are related to each other may be previously recorded in the memory 2123 of the electronic sphygmomanometer 2100, and the shift correction values ​​may be read out from the table.

[0100] For this reason, an accurate blood pressure value can be calculated while suppressing the influence of error caused by the difference in the maximum value of the pressure pulse wave amplitude by correcting the shift correction values ​​ζ, η based on the information of the value Pcamp or the cuff pressure at the point where the pressure pulse wave amplitude becomes a maximum (AmpMax).

[0101] Next, an embodiment of correcting the displacement correction values ​​based on the wrapping strength of the cuff 2101 will be described as another example of the blood pressure measurement operation. In the case of the electronic blood pressure monitor 2100, compared to the case where the cuff 2100 is appropriately wrapped around the measurement site, such as arm A (refer to Fig. 12), in order not to form a space, a large amount of air is flowed into the air cushion in the cuff 2101 to apply the same pressure to the measuring point as when a space is formed between the measuring point and the cuff 2101.

[0102] As described above, the pressure pulse wave amplitude detects the volume change of the cuff 2101, which occurs with the volume change of artery B (see Fig. 12) than the pressure change, and thus the pressure pulse wave amplitude changes by the air volume in the cuff 2101, even if it is the volume change of the same artery, where the pressure pulse wave amplitude becomes smaller the larger the air volume becomes. For this reason, the component of the background pulse wave changes in accordance with the wrapping strength of the cuff 2101.

[0103] The displacement correction values ​​ζ, η of [Equation 7] therefore need to be corrected based on the wrapping thickness of the cuff 2101. In the present embodiment, the central processing unit 2120 calculates the systolic blood pressure calculation parameter and the diastolic blood pressure calculation parameter using a predetermined calculation shown in the following [Equation 10], in which the correction for the wrapping type of the cuff 2101 is added to [Equation 7], and optimizes the same. In other words, in the present embodiment, a predetermined index ξ is multiplied by the displacement correction value ζ to correct it, and a predetermined index σ is multiplied by the displacement correction value η to correct it. [Equation 10] Calculation parameters for systolic blood pressure = maximum value of the pressure pulse wave amplitude × α + ξ × ξ Calculation parameters for diastolic blood pressure = maximum value of the pressure pulse wave amplitude × β + η × σ

[0104] Here, in [Equation 10], ξ and σ are values ​​previously determined through an experiment. Such values ​​can be determined by a method of pre-recording a setting table for the displacement correction value (setting the third and fourth constants) in the memory 2123 of the electronic sphygmomanometer 2100, in which the values ​​and the wrapping strength of the cuff 2101 are related, and reading the values ​​from the table.

[0105] The wrapping strength of the cuff 2101 can be detected by the ratio of the change in the cuff pressure when pressurizing the cuff 2101 using the known techniques as described in Japanese Unexamined Patent Laid-Open No. 62-84738, Japanese Unexamined Patent Laid-Open No. 5-62538, and Japanese Patent No. 4134234.

[0106] For this reason, by correcting the displacement correction values ​​ζ, η based on the information on the wrapping thickness of the cuff 2101, an accurate blood pressure value can be calculated while suppressing the influence of error caused by the difference in the air volume in the cuff 2101 resulting from the difference in the wrapping thickness.

[0107] An embodiment of correcting the displacement correction values ​​based on the specifications (size) of the cuff 2101 will now be described as another example of the blood pressure measurement operation. In the case of the electronic sphygmomanometer 2100, the longer the circumferential length of the measurement site, the greater the attenuation of pressure transmission to artery B. For this reason, in order to perform accurate blood pressure measurement, the cuff 2101 must be selected with an appropriate size in accordance with the circumferential length of the measurement site. In other words, the longer the circumferential length of the measurement site, the longer the width (the direction orthogonal to the circumferential direction of the measurement site) and the length (circumferential direction of the measurement site) of the cuff 2101 must be. The width and length of the cuff suitable for the circumferential length of the measurement site are specified by the WHO (World Health Organization) and the World Health Organization, respectively.World Health Organization) or similar.

[0108] Since the size (width, length) of the cuff 2101 becomes longer as the circumference of the measurement site increases, the size of the air cushion in the cuff 2101 also increases. For this reason, the pressure pulse wave amplitude to be detected becomes smaller as the size of the cuff 2101 increases, so that the component of the background pulse wave also becomes smaller (see Fig. 7).

[0109] For this reason, the displacement correction values ​​of [Equation 7] need to be corrected by the size of the cuff 2101. In the present embodiment, the central processing unit 2120 calculates the systolic blood pressure calculation parameter and the diastolic blood pressure calculation parameter using a predetermined calculation shown in the following [Equation 11], in which the correction for the size of the cuff 2101 is added to [Equation 7], and optimizes them. In other words, in the present embodiment, a predetermined index τ is multiplied by the displacement correction value ζ to correct it, and a predetermined index υ is multiplied by the displacement correction value η to correct it. [Equation 11] Calculation parameters for systolic blood pressure = maximum value of the pressure pulse wave amplitude × α + ξ × τ Calculation parameters for diastolic blood pressure = maximum value of the pressure pulse wave amplitude × β + η × υ

[0110] Here, in [Equation 11], τ and υ are values ​​previously determined through an experiment. Such values ​​can be determined by a method of pre-recording a setting table for the displacement correction value (setting the third and fourth constants) in the memory 2123 of the electronic sphygmomanometer 2100, in which the values ​​and the size of the cuff 2101 are related, and reading the values ​​from the table.

[0111] For this reason, an accurate blood pressure value can be calculated while suppressing the influence of error caused by the difference in the size of the air cushion in the cuff 2101 by correcting the displacement correction values ​​ζ, η based on the information on the size of the cuff 2101.

[0112] The size of the cuff 2101 may be input before measurement with a switch arranged in the input unit such as the operation unit 2130, or it may be automatically detected by disposing a sensor for detecting the size of the cuff 2101 at the connecting portion with the cuff 2101 of the main body of the electronic blood pressure monitor 2100.

[0113] By disposing a switch in the input unit such as the operation unit 2130 and allowing various types of information such as the size of the cuff 2101 to be input before measurement, various types of information necessary for calculating the blood pressure value can be acquired in advance in a simple manner and the time required for blood pressure measurement can be shortened.

[0114] Since the volume of air flowing into the cuff 2101 until a predetermined cuff pressure is reached increases in accordance with the increase in the size of the cuff 2101, the elapsed time also increases. Therefore, the time until the predetermined cuff pressure is reached can be measured based on the change in cuff pressure during blood pressure measurement, and the size of the cuff 2101 can be detected based on this time.

[0115] Therefore, different types of information can be acquired with a simple configuration without separately disposing the input unit, the sensor, or the like for inputting different types of information required for calculating the blood pressure value, such as the size of the cuff 2101.

[0116] The case of correcting the displacement correction values ​​ζ, η based on the information related to the size of the cuff 2101 from the information related to the specifications of the cuff 2101 has been described, but the correction can also be performed based on the information related to the type, such as the structure and the material, from the information related to the specifications of the cuff 2101. For example, with regard to the cuff in which the structure of the air cushion in the cuff 2101 is a single structure like a balloon and the cuff in which a gusset structure is provided on the side surface of the air cushion, as described in Japanese Patent No.3747917, the volume of air that flows into the air cushion so that the cuff 2101 reaches the predetermined internal pressure is greater, the softer the material of the air cushion of the cuff 2101 is.

[0117] In contrast, by correcting the displacement correction values ​​ζ, η based on the information related to the type of the cuff 2101, an accurate blood pressure value can be calculated while suppressing the influence of error caused by the difference in the air volume by the type of the cuff 2101.

[0118] As described above, the longer the circumferential length of the measurement site, the larger the size of the cuff 2101 used for measurement. For this reason, the shift correction values ​​(third and fourth constants) of [Equation 11] can be adjusted around the circumferential length of the measurement site based on the fact that the component of the background pulse wave changes in accordance with the size of the cuff 2101, as shown in Fig. 8. In this way, an accurate blood pressure value can be calculated while suppressing the influence of error caused by the difference in the size of the cuff 2101.

[0119] The expansion of the air cushion in the cuff 2101 becomes larger the softer the condition of the measurement site. In this case, a state similar to that in which there is a space between the measurement site and the cuff 2101 is created, and the pressure pulse wave amplitude becomes small. Therefore, correction can be performed by the condition of the measurement site. An accurate blood pressure value can thus be calculated while suppressing the influence of errors caused by the difference in the expansion of the air cushion of the cuff 2101.

[0120] In this case, the circumferential length or the condition of the measurement site may be input from the input unit such as the operation unit 2130, or the time until the predetermined cuff pressure is reached may be measured based on the change in cuff pressure in a single blood pressure measurement, and the circumferential length or the condition may be detected based on that time. The input of the condition of the measurement site may be replaced by BMI (Body Mass Index), the percentage of body fat, or the like. For example, if the percentage of body fat is large, it is determined that a large amount of fat exists at the measurement site, and correction may be made assuming that the condition of the measurement site is soft.

[0121] For this reason, the information related to the measuring point can be acquired with a simple configuration without separately arranging the input unit, the sensor, or the like for inputting different types of information related to the measuring point.

[0122] An embodiment of correcting the shift correction values ​​based on the user information input before starting the blood pressure measurement will now be described as another example of the blood pressure measurement operation. In the case of the electronic blood pressure meter 2100, the shape of the envelope curve shown in Fig. 9, in accordance with the dynamic properties of the artery. In Fig. 14 is a graph showing an example of the dynamic properties of the artery, where one of the factors for determining the dynamic properties of the artery includes the elasticity of the artery, as shown in Fig. 14. The elasticity of the artery depends on age and disease (especially arteriosclerosis), and the elasticity of the artery becomes harder with increasing age and the progression of the disease. When the elasticity of the artery becomes hard, it is almost impossible to close the artery by pressure, even when compressed with the cuff 2101. Thus, the background pulse wave persists until the cuff pressure becomes high compared to a person with soft artery elasticity.

[0123] The age and disease information is input in advance, and the shift correction values ​​ζ, η of [Equation 7] are corrected with the age and disease information. In the present embodiment, the age and disease information can be input using the input unit such as the operation unit 2130, and the central unit 2120 calculates the systolic blood pressure calculation parameter and the diastolic blood pressure calculation parameter using a predetermined calculation shown in the following [Equation 12], in which the correction based on the input age and disease information is added to [Equation 7], and optimizes them.In other words, in the present embodiment, a predetermined index □ is multiplied by the shift correction value ζ to correct the same, and a predetermined index χ is multiplied by the shift correction value η to correct the same. [Equation 12] Calculation parameters for systolic blood pressure = maximum value of the pressure pulse wave amplitude × α + ξ × □ Calculation parameters for diastolic blood pressure = maximum value of the pressure pulse wave amplitude × β + η × χ

[0124] Here, in [Equation 12], □ and χ are values ​​previously determined through an experiment. The information on the user and the age or diseases can be recorded in the memory 2123 in association with each other, and the information can be read out from the memory 2123 by selecting the user by the operation unit 2130 at the start of the measurement. The information on the age and diseases can be recorded in a medium such as the external memory 2172, and the information can be read out at the start of the measurement.

[0125] In the case of the present invention, the time until a predetermined cuff pressure is reached is measured based on the change in the cuff pressure in a single blood pressure measurement, the elasticity of the user's artery B is detected based on the time, and the information on the disease (in this case, information on arteriosclerosis) can be acquired based on the result of the detection.

[0126] For this reason, an accurate blood pressure value can be calculated while suppressing the influence of error caused by the difference in elasticity of artery B by correcting the displacement correction values ​​ζ, η based on the information on the user's age and diseases.

[0127] The present invention is not limited only to the configuration of the embodiments described above, and a large number of embodiments can be realized.

[0128] For example, the electronic blood pressure monitor 2100 may be configured to download a suitable parameter, threshold, algorithm, or the like from a dedicated server to expand its functionality. In this case, the software version can be upgraded with the existing hardware, or optimization can be easily implemented by the user.

[0129] The functional expansion of the electronic blood pressure monitor 2100 can be performed from an operating terminal, such as a personal computer, owned by the user without using the server. In this case, the parameter, threshold, algorithm, and the like can be downloaded from a recording medium, such as a CD-ROM.

[0130] The electronic blood pressure monitor 2100 can be communicatively connected, either wirelessly or via a wired connection, to another biological information sensing device, such as a body composition monitor, a pedometer, or an electronic thermometer. In this case, data can also be mutually transmitted and received to improve individual accuracy. INDUSTRIAL APPLICABILITY

[0131] The present invention can be applied to an electronic blood pressure monitor employing an oscillometric method using a cuff. DESCRIPTION OF SYMBOLS 2100 blood pressure monitor 2101 cuff 2103 pressure sensor 2104 Pump 2105 Valve 2120 CPU or central unit 2121 display unit 2122 memory (for processing) 2123 memory (for recording) 2130 operating unit

Claims

[1] An electronic blood pressure monitor (2100) comprising: Cuff (2101) attached to a blood pressure measuring point; Pressurization and depressurization means (2102, 2104, 2105, 2112, 2113) for adjusting a pressure applied to the cuff (2101); Pressure detection means (2103) for detecting a pressure in the cuff; Blood pressure calculating means (2120) for calculating a blood pressure value from a cuff pressure; Recording means (2122, 2123) for recording the blood pressure value, and Operating means (2130) for performing an operation, such as measuring blood pressure; wherein the blood pressure calculation means (2120) has a configuration adapted to calculate a calculation parameter for blood pressure by performing a predetermined calculation using a constant (α, β, ζ, ζtsys, η, ηtdia) previously set in view of a change in a pressure pulse wave amplitude indicative of a volume change in an artery at the time of blood pressure measurement; and the electronic blood pressure monitor (2100) also includes: Information acquisition means for separately acquiring measurement condition-related information relating to a condition of the user and / or a condition of the cuff (2101) at the time of blood pressure measurement; and Correction means for correcting the calculation parameter for blood pressure by correcting the constants (α, β, ζ, ζtsys, η, ηtdia) based on the information related to the measurement state when the information related to the measurement state is acquired by the information acquisition means, characterized by , that the blood pressure calculation means (2120) for the blood pressure has a configuration adapted to calculate a calculation parameter for the systolic blood pressure based on a predetermined calculation of multiplying a first constant (α) by a maximum value of the pressure pulse wave amplitude and adding a third constant (ζ, ζtsys) related to a component of a background pulse wave generated when the pressure in the cuff (2101) is pressurized to a predetermined pressure outside a predetermined measurement range for the blood pressure value, and to calculate a calculation parameter for the diastolic blood pressure based on a predetermined calculation of multiplying a second constant (β) by a maximum value of the pressure pulse wave amplitude and adding a fourth constant (η, ηtdia) related to a component of a background pulse wave; and the correction means corrects the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the information related to the measurement state. [2] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquisition means has a configuration adapted to acquire information on a temporarily set blood pressure value as the measurement condition-related information related to the condition of the user; and the correction means has a configuration arranged to correct the first and second constants (α, β) or the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the temporarily set blood pressure value. [3] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquisition means has a configuration adapted to acquire information on a maximum value of the cuff pressure as the measurement condition-related information; and the correction means has a configuration arranged to correct the first and second constants (α, β) or the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the maximum value of the cuff pressure. [4] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquisition means has a configuration adapted to acquire information on a maximum value of the pressure pulse wave amplitude as the measurement condition-related information related to the condition of the user; and the correction means has a configuration adapted to correct the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the maximum value of the pressure pulse wave amplitude. [5] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquiring means has a configuration adapted to acquire information on a wrapping thickness of the cuff (2101) as the measurement state-related information; and the correction means has a configuration arranged to correct the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the information on the wrapping thickness of the cuff (2101). [6] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquisition means has a configuration adapted to acquire information on the specification of the cuff (2101) related to a size and / or a type of the cuff (2101) as the measurement condition-related information; and the correction means has a configuration arranged to correct the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the information on the specification of the cuff (2101). [7] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquisition means has a configuration configured to acquire information related to a user's measuring point as the measurement status-related information; and the correction means has a configuration designed to correct the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the information related to the user's measuring point [8] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquisition means has a configuration adapted to acquire information on the user's illnesses as the information related to the measurement condition; and the correction means has a configuration designed to correct the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the information on the user's diseases. [9] Electronic blood pressure monitor (2100) according to claim 1, wherein the information acquisition means has a configuration adapted to acquire age information of the user as the measurement condition-related information; and the correction means has a configuration configured to correct the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the user's age information. [10] The electronic blood pressure monitor (2100) according to claim 1, wherein the information detecting means has a configuration adapted to detect the information related to the measurement state based on a change in the internal pressure of the cuff (2101). [11] Electronic blood pressure monitor (2100) according to claim 1, further comprising: Input means for allowing the user to enter information related to the measurement status; wherein the information acquisition means has a configuration adapted to acquire the information related to the measurement status which was entered before the start of the blood pressure measurement. [12] A blood pressure measurement method for adjusting a pressure applied to a cuff (2101) by pressurizing and depressurizing means (2102, 2104, 2105, 2112, 2113) when the cuff (2101) is attached to a blood pressure measuring site, and calculating a blood pressure value with blood pressure calculating means (2120) based on the cuff pressure detected by a pressure detecting means (2103); the method comprising the steps of: Calculating a calculation parameter for blood pressure by performing a predetermined calculation in the blood pressure calculation means (2120) using a constant (α, β, ζ, ζtsys, η, ηtdia) previously set with respect to a maximum value of a pressure pulse wave amplitude indicative of a volume change of an artery at the time of blood pressure measurement (S2168), separately recording information related to the measurement condition, which is related to a condition of the user and / or a condition of the cuff at the time of the blood pressure measurement, with an information recording means; and Correcting the calculation parameter for blood pressure by correcting the constants (α, β, ζ, ζtsys, η, ηtdia) with a correction means based on the information related to the measurement state by correction means when the information related to the measurement state is acquired by the information acquisition means characterized by , that the step of calculating the calculation parameter for blood pressure by the blood pressure calculation means (2120) comprises calculating a calculation parameter for systolic blood pressure based on a predetermined calculation of multiplying a first constant (α) by a maximum value of the pressure pulse wave amplitude and adding a third constant (ζ, ζtsys) related to a component of a background pulse wave, and calculating a calculation parameter for diastolic blood pressure based on a predetermined calculation of multiplying a second constant (β) by a maximum value of the pressure pulse wave amplitude and adding a fourth constant (η, ηtdia) related to a component of a background pulse wave; and the step of correcting by the correcting means comprises correcting the third and fourth constants (ζ, ζtsys, η, ηtdia) based on the information related to the measurement state.

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