JP4795777B2 - Blood pressure measurement cuff, blood pressure measurement device, and blood pressure measurement method - Google Patents

Description

  The present invention relates to a blood pressure measurement cuff and a blood pressure measurement device, and more particularly, to a blood pressure measurement cuff that performs non-invasive blood pressure measurement using an oscillometric method using an ischemic cuff and a blood pressure measurement device using the cuff.

  According to the conventional oscillometric sphygmomanometer, the pressure of the ischemic cuff is gradually increased to a pressure higher than the systolic blood pressure, or is positioned below the ischemic cuff while being lowered from the pressure higher than the systolic blood pressure. Based on the change in the volume of the artery, the vibration of the cuff pressure is detected, and the blood pressure is determined by the change in the amplitude of the vibration.

  The method for obtaining the systolic blood pressure in the blood pressure measurement method using such an ischemic cuff is to increase the pressure of the ischemic cuff above the systolic blood pressure, which is the highest pressure in the artery, while the arterial blood flow stops. By lowering, blood flow is detected and detected.

  On the other hand, according to the Korotkoff method (auscultation method), which is now widely used, the blood pressure is stopped by raising the pressure of the ischemic cuff more than the systolic blood pressure, and then gradually increasing the pressure of the ischemic cuff. The systolic blood pressure value (maximum blood pressure value) and the diastolic blood pressure value (minimum blood pressure value) are obtained by detecting the Korotkoff sound generated at the timing of lowering and resuming blood flow downstream of the ischemic cuff. .

  The oscillometric method captures the phenomenon of blood flow resumption as pressure vibration of the ischemic cuff based on the arterial volume change under the ischemic cuff, and detects it mainly from the amplitude change which is a change of the pulse wave. For this reason, in the oscillometric method, compared to the Korotkoff method, the position of the sensor (including the stethoscope) for detecting Korotkoff sounds from the artery, the influence of external noise (cuff cloth, cuff tube scratching sound, vibration) ) Is a method that can be measured without receiving it, and is widely used for automatic sphygmomanometers.

  However, the oscillometric method has a problem in detecting systolic blood pressure due to the blood vessel compression characteristics of the Rivaroch cuff used in the ischemic cuff. In other words, the Rivaroch cuff can obtain a compression force reflecting the cuff pressure in the central portion in the width direction, but if it deviates from the central portion, a compression force reflecting the cuff pressure cannot be obtained, and from the central portion to the end of the cuff. The compression force gradually decreases, and the end portion exhibits a characteristic that becomes zero.

  Due to such characteristics, the blood flow is stopped at the center of the cuff when the cuff pressure of the ischemic cuff is slightly higher than the systolic blood pressure at the timing when the systolic blood pressure is to be measured. As a result, a phenomenon occurs in which the blood flow enters and returns from the upstream portion of the direct blood cuff to the central portion of the ischemic cuff in synchronization with the pulsation of the heart. By this phenomenon, a pulse wave is already detected before the timing at which the blood flow resumes.

  In addition, when the cuff pressure of the ischemic cuff becomes lower than the systolic blood pressure and the blood flow resumes, a volume change due to the blood flow occurs downstream from the center under the ischemic cuff. Because the cuff pressure is slightly lower than the arterial pressure, the blood vessel closes immediately after opening for a short time. At this time, the volume change on the downstream side under the ischemic cuff is very small compared to the volume change on the upstream side. The pulse wave detected by the oscillometric method is based on the volume change in which the upstream volume change and the downstream volume change under the above-mentioned ischemic cuff are overlapped. It is very difficult to select and detect when blood flow is small. As described above, the oscillometric method causes the deterioration of the S / N ratio in the measurement of systolic blood pressure as compared with the Korotkoff method.

  As described above, detection may be difficult due to a change caused by resumption of blood flow. Therefore, conventionally, the following measures have been taken. If the pressure of the ischemic cuff is further lowered from the systolic blood pressure, the time when the arterial pressure becomes higher than the pressure of the ischemic cuff becomes longer in the heart cycle, and the downstream side under the ischemic cuff As the volume change increases, the amplitude of the pulse wave gradually increases. In addition, since the intravascular pressure at the peripheral site is greater than the ischemic cuff pressure than the ischemic cuff, the volume change under the ischemic cuff is the entire upstream and downstream side of the vessel volume under the ischemic cuff and the pulse wave amplitude is maximum. The following phenomenon occurs. The volume change at this time is a change upstream of the cuff center corresponding to 50% of the blood vessel volume under the ischemic cuff at the time of systolic blood pressure measurement. Approximately twice the pulse wave amplitude during systolic blood pressure measurement. Utilizing this, a method is adopted in which the systolic blood pressure is set at a timing at which the pulse wave amplitude is about 50% of the maximum pulse wave amplitude.

  However, this ratio depends on the upstream and downstream volume imbalances, cuff compliance differences, the degree of increase in intravascular pressure at the peripheral site, timing Affected by. This increase in peripheral blood pressure is affected by congestion due to the short time required for repeated blood pressure measurements, but it is mainly influenced by blood pressure values, the degree of peripheral circulation, and peripheral vascular compliance. ing.

A double cuff system has been devised to solve these problems. This double cuff method is a method in which an ischemic cuff used for blood vessel compression and a detection cuff for detecting only a pulse wave at a central portion under the ischemic cuff are provided separately from the ischemic function. According to this double cuff method, the pulse wave based on the volume change on the upstream side under the ischemic cuff at the time of measuring the systolic blood pressure, which is a problem in the oscillometric method, can be eliminated, and ischemia that serves as a guideline for determining the systolic blood pressure The volume change on the downstream side under the cuff can be detected with a good S / N ratio. (Patent Document 1)
However, at the detection timing of systolic blood pressure, the blood flow that invades the upstream side under the cuff for ischemia has entered the immediate vicinity of the cuff for pulse wave detection, which is detected by the cuff for pulse wave detection, Since the pulse wave detection cuff is provided under the ischemic cuff, a phenomenon that the cuff vibration based on the upstream volume change under the ischemic cuff detected by the ischemic cuff is transmitted to the contacting pulse cuff May cause the S / N ratio of the systolic blood pressure measurement to deteriorate.

Therefore, a backing is provided to improve the compression performance of the pulse wave detection cuff so that the blood flow entering from the upstream side of the pulse wave detection cuff does not approach when the blood vessel is closed by the ischemic cuff. Install a cushioning material for damping the transmitted pulse wave from the ischemic cuff between the pulse wave detection cuff and the ischemic cuff, and further to dump the pulse wave upstream under the ischemic cuff Proposals for providing cushioning materials have also been made. (Patent Document 2)
However, according to this proposal, the compression force of the pulse wave detection cuff can be improved, but there is a limit to the extent to which the ischemic point is separated from the pulse wave detection cuff. In addition, since the damping characteristics of the members used are limited, a relatively high frequency component of the pulse wave can be attenuated, but a low component cannot be sufficiently attenuated.
JP 2004-195056 A Japanese Patent Laid-Open No. 2004-321251

  Therefore, the present invention has been made in view of such a situation, and more effectively eliminates the influence of the volume change of the upstream portion of the ischemic cuff on the pulse wave detection cuff of the double cuff method by the oscillometric method. Thus, an object of the present invention is to provide a blood pressure measurement device and a blood pressure measurement method capable of improving the S / N ratio for detection of systolic blood pressure.

  In order to solve the above-described problem, according to the blood pressure measurement device of the present invention, a cuff for ischemia that compresses an artery at a blood pressure measurement site, and a pulse wave that is disposed at a substantially central portion below the cuff for ischemia. A pulse wave detection cuff to be detected; a sub-cuff disposed on the heart side of the substantially central portion below the ischemic cuff; a pressurization control unit connected to the ischemic cuff and the sub-cuff; A pressure detection unit that is connected to the pulse wave detection cuff and converts the pulse wave into a detection cuff signal, the ischemic cuff, the decompression control unit, the volume buffer unit, and the pulse A fluid resistance unit connected to the wave detection cuff, a pulse wave detection unit that detects a pulse wave superimposed on the detection cuff signal, an output of the pulse wave detection unit, and a detection cuff signal of the cuff pressure detection unit A blood pressure detector for determining a blood pressure value based on It is characterized in that it comprises a blood pressure display unit for displaying the blood pressure value from the blood pressure detecting part.

  In addition, a first backing member is disposed between the ischemic cuff and the pulse wave detection cuff, and a second backing member is disposed between the ischemic cuff and the sub-cuff.

  In addition, according to the blood pressure measurement method of the present invention, the ischemic cuff for compressing the artery of the blood pressure measurement site, and the pulse wave detection cuff that is disposed at a substantially central portion below the ischemic cuff and detects a pulse wave. And a blood pressure measurement method using a sub-cuff disposed closer to the heart than the substantially central portion below the ischemic cuff, the ischemic cuff and a pressurization control unit connected to the sub-cuff; A step of compressing the artery via a decompression control unit and a volume buffer unit; a step of converting the pulse wave into a detection cuff signal by a pressure detection unit connected to the pulse wave detection cuff; A step of depressurizing each cuff via a fluid resistance unit connected to the cuff, the depressurization control unit, the volume buffer unit, and the pulse wave detection cuff; and a pulse wave detection unit that superimposes the detected cuff signal on the cuff Pulse wave detection process and blood pressure detection And determining the blood pressure value based on the output of the pulse wave detection unit and the detection cuff signal of the cuff pressure detection unit, and displaying the blood pressure value from the blood pressure detection unit in the blood pressure display unit. It is characterized by providing.

  In addition, a first backing member is disposed between the ischemic cuff and the pulse wave detection cuff, and a second backing member is disposed between the ischemic cuff and the sub-cuff.

  Further, according to the computer-readable storage medium storing the control program of the blood pressure measurement method of the present invention, the ischemic cuff for compressing the artery of the blood pressure measurement site, and the substantially central portion below the ischemic cuff Stored is a control program for a blood pressure measurement method using a pulse wave detection cuff that is disposed and detects a pulse wave, and a sub-cuff that is disposed closer to the heart than the substantially central portion below the ischemic cuff. A computer-readable storage medium, comprising: a program for compressing the artery via a pressurization control unit, a decompression control unit, and a volume buffer unit connected to the ischemic cuff, the sub-cuff; A program for converting the pulse wave into a detection cuff signal by a pressure detection unit connected to the pulse wave detection cuff, the ischemic cuff, the decompression control unit, the volume buffer unit, and the A program for depressurizing each cuff via a fluid resistance unit connected to a wave detection cuff, a program for detecting a pulse wave superimposed on the detection cuff signal in a pulse wave detection unit, and blood pressure detection The blood pressure value is output from the pulse wave detection unit and a detection cuff signal from the cuff pressure detection unit, and the blood pressure display unit displays the blood pressure value from the blood pressure detection unit. It is characterized by comprising a process program.

  Further, the blood pressure measurement cuff includes a ischemic cuff that compresses an artery at a blood pressure measurement site, a pulse wave detection cuff that is disposed at a substantially central portion below the ischemic cuff and detects a pulse wave, and the ischemic And a sub-cuff disposed on the heart side of the substantially central portion below the cuff.

  And a cuff for ischemia that compresses the artery of the blood pressure measurement site, a cuff for pulse wave detection that is disposed at a substantially central portion below the cuff for cuff and has a backing material on the outside thereof, and detects a pulse wave; And a sub-cuff disposed on the heart side of the substantially central portion below the ischemic cuff.

  Further features of the present invention will become apparent from the best mode for carrying out the present invention and the accompanying drawings.

  According to the blood pressure measurement device and blood pressure measurement method of the present invention, by providing a sub-cuff on the upstream side under the ischemic cuff in addition to the double-cuff ischemic cuff and the pulse wave detection cuff, it is a disadvantage of the Rivaroch cuff used for the ischemic cuff. By substituting the pressure change of the sub-cuff to which the same pressure as the ischemic cuff is applied, the change in the compression pressure that occurs from the central part of the cuff toward the cuff end is reinforced under the ischemic cuff timing. It is possible to prevent blood from flowing into the upstream part of the tube and to accurately detect only the pulse wave change due to the volume change on the downstream side under the ischemic cuff based on the resumption of blood flow with improved S / N ratio Become.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a blood pressure measurement device according to an embodiment of the present invention.

  According to the embodiment of the figure, the sub cuff 3 is connected to the living body of the ischemic cuff so that the sub cuff 3 can be positioned between the blood pressure measurement site upstream of the ischemic cuff 1 and the ischemic cuff 1. It is arranged approximately in the middle of the upstream end of the ischemic cuff from the end 2 of the wave detection cuff.

  The blood pressure measurement device in FIG. 1 includes a device body 10 and a cuff 100 attached to a blood pressure measurement site. As shown in the figure, the cuff 100 is mounted so that the upstream portion of the cuff is on the left ventricular side where the blood flow of the artery at the blood pressure measurement site flows. This cuff 100 is configured by providing a cuff 1 for blocking blood, a cuff 2 for detecting a pulse wave, and a sub-cuff 3 on a cuff cloth 5 that wraps the cuff, and for fixing the cuff 100 after it is wound around a blood pressure measurement unit. Has a hook-and-loop fastener. Further, the cuff 100 may be provided with a backing member on the cuff cloth 5 and the cuff on the opposite side of the surface of the cuff 1 for ischemic contact with the living body.

  A pipe 7 is connected to the pulse wave detection cuff 2, and a pipe 6 is connected to the sub-cuff 1 and the ischemic cuff 1 via branch portions 6 a and 6 b, respectively. In addition, the connector 38 is detachably connected between the ischemic cuff 1 and the main body 10 and between the pulse wave detection cuff 2 and the main body 10, but may be integrated piping.

In order to eliminate the pulse wave detected by the sub-cuff 3, a volume buffer 12 of about 500 ml is branched from the middle of the pipe 6 to the cuff 1 and the sub-cuff 3 as shown. The volume of the sub-cuff 3 is A to B / 2 ml, where the volume of the pulse wave detection cuff 2 is Aml and the capacity of the ischemic cuff 1 is Bml, thereby improving the S / N ratio for measuring systolic blood pressure. To do.
On the other hand, a fluid resistance 11, a pressurization control unit 19 that controls the air pressure from the pump 18, and a decompression control unit 20 that performs decompression exhaust control are installed in the pipe 7 of the pulse wave detection cuff 2.

  The pipe 7 connected to the pulse wave detection cuff 2 is connected to a cuff pressure detection unit 13 having a pressure sensor, and the pulse wave superimposed on this output from the output of the cuff pressure detection unit 13. A signal is sent to the pulse wave detection unit 14 for detecting the blood pressure, the cuff pressure from the cuff pressure detection unit 13 and the blood pressure from the pulse wave detection unit 14 are determined by the blood pressure detection unit 15, and the determined blood pressure value is displayed on the liquid crystal display. The blood pressure display unit 16 provided with a device or the like is configured to display.

  Further, the main body 10 includes a power source unit 17 such as a battery, and controls the pump and each control unit, and supplies power to a CPU including a ROM, a RAM, and the like storing various control programs readable by a computer. Like to do.

  2 is a cross-sectional view after the cuff 100 is broken in the width direction and attached to the measurement site. In this figure, the question of the pulse wave detection cuff 2 and the ischemic cuff 1 is to prevent vibration caused by the pulse wave from the pulse wave detection cuff 2 and to increase the compression characteristics of the pulse wave detection cuff 2. 1 is a backing member 25 for detecting a cuff for detecting a pulse wave. Further, in order to enhance the pressure beat characteristics of the sub-cuff 3, a sub-cuff backing portion 30 which is a second backing member is provided between the sub-cuff 3 and the blood-cushion cuff 1.

  According to the blood pressure measurement device configured as described above, the stored control program can be read out by a computer and operated as shown in the flowchart of the blood pressure measurement routine in FIG.

  First, when it is activated, pressurization is started by the pressurization control unit in step S1, and the process proceeds to step S2. In this step S2, 20-30 mmHg higher than the expected systolic blood pressure is set as a set pressure, and it is checked by the signal of the cuff pressure detection unit whether the pressure of the cuff 1 for ischemia has reached the set pressure. Run until. When the pressure of the cuff 1 for ischemia reaches the set pressure, the pressurization control unit stops pressurization in step S3.

  Then, it progresses to step S4, and pressure reduction is started so that a pressure reduction speed may be 2-3 mmHg / sec using the signal from a cuff pressure detection part by a pressure reduction control part. Subsequently, in step S5, the detection of the pulse wave is started from the signal from the cuff pressure detector. The pulse wave signal detected by the pulse wave detection unit is sent to a storage unit in the blood pressure detection unit, and the cuff pressure and the pulse wave amplitude are stored as a set. In step S6, the blood pressure detection unit detects the maximum value of the pulse wave amplitude, detects that the pulse wave amplitude continuously decreases, and detects the previous pulse wave that starts decreasing as the pulse wave maximum value. To do.

  Then, it progresses to step S7, the pulse wave which becomes 60% or less of the pulse wave maximum value is detected in the blood pressure detector, and the cuff pressure at that time is determined as the diastolic blood pressure. When the systolic blood pressure is determined, the process proceeds to step S8, and the pressure is reduced by the decompression control unit. In step S9, from the data in which the cuff pressure and the pulse wave amplitude recorded in the blood pressure detection unit are a set, a change in which the pulse wave amplitude is suddenly increased by 50% or more after the start of pressure reduction is performed. The detected pressure value of the pulse wave whose amplitude suddenly increases is determined as the diastolic blood pressure. When determined in this way, in step S10, the systolic blood pressure value and the diastolic blood pressure value are displayed on the blood pressure display unit, and the series of blood pressure measurement operations is terminated.

  FIG. 4 shows the pulse wave amplitude and cuff pressure stored in the blood pressure determination unit in time series. (A) shows the detected pulse wave amplitude change when the sub-cuff is not used, and (b) shows the detected pulse wave amplitude change when the sub-cuff of the present invention is used.

  As shown in the figure, compared with the waveform of FIG. 4A, the waveform of FIG. 4B has a clear pulse wave amplitude change at the systolic blood pressure detection timing.

  As described above, even when the cuff pressure for ischemia is higher than the systolic blood pressure, the blood flow entering the lower cuff upstream of the cuff for cuff can be blocked by the sub-cuff. Detection was possible with a good S / N ratio, and the determination accuracy of the systolic blood pressure value could be improved.

It is a block diagram which shows the blood pressure measuring device of one Embodiment of this invention. It is sectional drawing of the cuff of FIG. 2 is an operation explanatory flowchart of the blood pressure measurement device in FIG. 1. (A) is the detected pulse wave amplitude change when the sub-cuff is not used, and (b) is the detected pulse wave amplitude change when using the sub-cuff of the present invention, the pulse wave amplitude and the cuff pressure stored in the blood pressure determining unit. It is the chart which displayed chronologically.

Explanation of symbols

1 Cuff for ischemia 2 Cuff for pulse wave detection 3 Sub cuff 5 Cuff cloth 6 and 7 Pipe 10 Body 25 Backing part for cuff for pulse wave detection

Claims (6)

An ischemic cuff for compressing an artery at a blood pressure measurement site; a pulse wave detecting cuff which is disposed at a substantially central portion below the ischemic cuff and detects a pulse wave; and the substantially central below the ischemic cuff A sub-cuff placed on the heart side of the part,
A pressurization control unit, a depressurization control unit, and a volume buffer unit connected to the ischemic cuff, the sub-cuff,
A pressure detector that is connected to the pulse wave detection cuff and converts the pulse wave into a detection cuff signal;
A fluid resistance unit connected to the cuff for ischemia, the decompression control unit, the volume buffer unit and the pulse wave detection cuff;
A pulse wave detection unit for detecting a pulse wave superimposed on the detection cuff signal;
A blood pressure detector that determines a blood pressure value based on an output of the pulse wave detector and a detection cuff signal of the cuff pressure detector;
And a blood pressure display unit that displays a blood pressure value from the blood pressure detection unit.   The first backing member is disposed between the ischemic cuff and the pulse wave detection cuff, and the second backing member is disposed between the ischemic cuff and the sub-cuff. The blood pressure measurement device described in 1. An ischemic cuff for compressing an artery at a blood pressure measurement site; a pulse wave detecting cuff which is disposed at a substantially central portion below the ischemic cuff and detects a pulse wave; and the substantially central below the ischemic cuff A blood pressure measurement method using a sub-cuff arranged on the heart side of the part,
Compressing the artery via the ischemic cuff, a pressurization control unit connected to the sub-cuff, a depressurization control unit, and a volume buffer unit;
A step of converting the pulse wave into a detection cuff signal by a pressure detection unit connected to the pulse wave detection cuff;
Depressurizing each cuff through a fluid resistance connected to the ischemic cuff, the depressurization control unit, the volume buffer unit, and the pulse wave detection cuff;
A step of detecting a pulse wave superimposed on the detection cuff signal in the pulse wave detection unit;
In the blood pressure detection unit, a step of determining a blood pressure value based on the output of the pulse wave detection unit and the detection cuff signal of the cuff pressure detection unit;
And a step of displaying a blood pressure value from the blood pressure detection unit in the blood pressure display unit. An ischemic cuff for compressing an artery at a blood pressure measurement site; a pulse wave detecting cuff which is disposed at a substantially central portion below the ischemic cuff and detects a pulse wave; and the substantially central below the ischemic cuff A computer-readable storage medium storing a control program of a blood pressure measurement method using a sub-cuff arranged on the heart side of the unit,
A program of a step of compressing the artery via a pressurization control unit, a decompression control unit, and a volume buffer unit connected to the ischemic cuff and the sub-cuff;
A program for converting the pulse wave into a detection cuff signal by a pressure detection unit connected to the pulse wave detection cuff;
A program for depressurizing each of the cuffs via a fluid resistance unit connected to the cuff for ischemia, the decompression control unit, the volume buffer unit, and the pulse wave detection cuff;
In the pulse wave detector, a program for detecting a pulse wave superimposed on the detection cuff signal;
In the blood pressure detection unit, a program for determining a blood pressure value based on the output of the pulse wave detection unit and the detection cuff signal of the cuff pressure detection unit,
A computer-readable storage medium storing a blood pressure measurement method program comprising a program for displaying a blood pressure value from the blood pressure detection unit in the blood pressure display unit.   An ischemic cuff for compressing an artery at a blood pressure measurement site; a pulse wave detecting cuff which is disposed at a substantially central portion below the ischemic cuff and detects a pulse wave; and the substantially central below the ischemic cuff A blood pressure measurement cuff, comprising: a sub-cuff disposed on the heart side of the portion.   A cuff for ischemia that compresses an artery at a blood pressure measurement site; a cuff for detecting a pulse wave that is disposed in a substantially central portion below the ischemic cuff and includes a backing material on the outside thereof to detect a pulse wave; and the ischemic A blood pressure measurement cuff comprising: a sub-cuff disposed on the heart side of the substantially central portion below the cuff.

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