JP5112767B2 - Blood pressure measurement device - Google Patents

Description

  The present invention relates to a blood pressure measurement device, and more particularly to a technique for measuring blood pressure using a cuff for ischemia.

According to the blood pressure measurement of oscillometric method, systolic raise the cuff pressure to a higher pressure than the blood pressure once pressure closing the vessel of the measurement site, the artery of the measurement site while depressurizing the cuff pressure gradually It measures the blood pressure by detecting a change in amplitude of the pulse wave in the cuff pressure signal generated on the basis of the volume change of the superimposed. Cuff used in blood pressure measurement has a strong force to press the most vessels in the central portion, a force for pressing the vessel toward the opposite ends of the cuff gradually decreases, a Kafuejji effect becomes substantially zero in the cuff ends Yes.

Amplitude change of the pulse wave at the time of blood pressure measurement by this characteristic, when the cuff pressure is sufficiently higher than the systolic blood pressure in synchronization with the beating of the heart than the heart side of the measurement site, blood flow cuff upstream ( It becomes almost constant due to the phenomenon that reaches the end of the heart and is returned.

  Further, when the cuff pressure is reduced, the blood flow from the heart side of the measurement site gradually enters the cuff central portion and invades while increasing the degree of invasion, and is pushed back. When the cuff is further depressurized, the blood vessel is closed in the center of the cuff, but the blood intrusion reaches the vicinity of the center of the cuff. Along with this, the pulse wave amplitude superimposed on the cuff pressure also changes gradually.

Apart from this phenomenon, the flow proceeds further decompression of the cuff, the cuff pressure is lower than the systolic blood pressure, that beats and out of the blood flow occurs (forearm side when the measurement site is the upper arm) distal of the cuff Become. Pulse wave amplitude to be superimposed on the cuff pressure, the volume variation in amplitude of output peripheral side beats increases.

  As the cuff is further depressurized, the pulse wave amplitude increases due to an increase in the output to the peripheral side. Furthermore, as the pressure decreases further, the forearm vein located more distal than the cuff is closed by the cuff with the increase in the output to the periphery, so that the intravascular pressure of the vein and the whole artery rises, and in one cardiac cycle Timing occurs when the intravascular pressure on the distal side becomes larger than the cuff pressure.

Due to the increase in the intravascular pressure, a baroreflex is generated from the peripheral site side, and the pulse wave amplitude is further increased by this reflection. As the cuff is further depressurized, the volume of the blood vessel during the systole increases, but due to the cuff edge characteristics, the cuff edge compression force is weakened, so the volume of the blood vessel that is capped during the diastole is increased. By decreasing, the pulse wave amplitude reaches a peak and gradually decreases. Further pressure reduction of cuff proceeds and the cuff pressure falls below diastolic pressure, prevents blood vessel in one cardiac cycle is pressure closed, the pulse wave amplitude will decrease more and more. When the cuff pressure reduction proceeds, the overall compliance cuff increases, the volume of cuff - a decrease in the pressure conversion efficiency, further pulse wave amplitude is a series of pulse wave amplitude variation which decreases occurs.

  The oscillometric method measures and predicts systolic blood pressure and diastolic blood pressure from this series of pulse wave amplitude changes.

In the measurement of the systolic blood pressure, but the detection of phenomena cardiac output to the cuff peripheral side is important, when the cuff pressure is systolic blood pressure above, the cuff upstream return flow of the cuff of a blood flow Occurrence of pulse waves due to. In addition, this pulse wave shows a gradually increasing change, and the amount of stroke to the downstream side is initially small, and the volume change due to the stroke is small compared to the blood vessel volume change on the cuff upstream side. It is difficult to detect the phenomenon.

The volume change of the subcuff blood vessel at the timing when the cuffing toward the peripheral side of the cuff is a state in which about half of the volume of the blood vessel under the cuff is open or closed. Therefore, since the timing at which substantially the entire blood vessel volume under the cuff is opened or closed, that is, approximately 50% of the timing at which the pulse wave amplitude becomes the largest, the pulse wave amplitude that appears after the decompression is started. If, record the cuff pressure at that time in pairs, the pulse wave amplitude is back in the recording from the point in which the maximum cuff pressure of when it is 50% of the maximum pulse wave amplitude, the systolic blood pressure The method of determining the value is adopted.

  However, the maximum pulse wave amplitude is affected by the vascular elasticity of the measurement site and the baroreflex from the cuff peripheral site. This baroreflex is caused by an increase in blood pressure in the forearm, which is the cuff peripheral region, and this increase in pressure is affected by the amount of blood flowing into the cuff peripheral region, the blood volume of the forearm, and vascular elasticity. This forearm blood is filled without being returned to the heart is called congestion. In addition to the characteristics of blood vessels, this congestion is likely to occur when the amount of blood flowing to the periphery during measurement is large, for example, when the cuff decompression rate during measurement is slow or when the pulse rate is high, and blood pressure measurement is repeated. Occasionally, this congestion is likely to occur unless the measurement interval is longer than the time required for the forearm blood flow to return to the heart. For this reason, since the maximum amplitude of the pulse wave is affected by the vascular elasticity of the individual measurement site of the individual to be measured, the likelihood of congestion, and the measurement interval, 50% of the maximum pulse wave amplitude is uniformly the systolic pressure. There is a problem of not becoming.

On the other hand, since the cuff pressure which is the target of the systolic blood pressure measurement is slightly lower than the systolic blood pressure, a small change accompanying the ejection to the cuff erasing is detected with a high S / N ratio. In addition to the cuff, a small cuff for pulse wave detection for selectively detecting the change in the volume of the blood vessel on the peripheral side is provided in the middle and the peripheral side of the cuff for ischemia, and the cuff for pulse wave detection via the cuff for cough In order to block the pulse wave signal upstream of the cuff that interferes with peripheral pulse wave detection, a cushioning material is provided between the cuff for ischemia and the cuff for pulse wave detection. There has been proposed a double cuff method in which an acoustic filter (for example, composed of a fluid resistance and a volume buffer tank) for attenuating the pulse wave of the ischemic cuff is provided in a connecting pipe with the pulse wave detection cuff (Patent Document 1).
JP 2005-185295 A

Also in Daburukafu method described above, when the cuff pressure is greater than the systolic blood pressure, arterial volume change due to the blood flow is present. The presence, attenuation and upstream pulse wave in an acoustic filter in order to prevent entry into pressure detecting portion of the upstream pulse wave as described above, the pulse between the air bag and the pulse wave detection air bag avascularization The propagation of wave vibration is blocked using a buffer material. However, in the acoustic filter, due to the problem of the pressure difference between the air bag for ischemia and the air bag for pulse wave detection due to the cuff decompression, the size of the volume buffer tank is limited by the limitation of the fluid resistance and the downsizing of the blood pressure measuring device In the buffer material, the arterial wave characteristics are limited due to the problem of reduced ischemic function, so the influence of the upstream pulse wave cannot be completely eliminated, which hinders measurement of systolic blood pressure. May occur.

In order to solve the above-described problems, according to the blood pressure measurement device of the present invention, a cuff member that is detachably attached to a blood pressure measurement site, and an air bag for ischemia that is contained in the cuff member and compresses the blood pressure measurement site. (A cuff for ischemia) and a sub-air (sub-cuff) bag that is laid on the opposite side of the blood bag for measuring blood pressure of the blood bag for ischemia and assists the compression of the air bag for blood pressure of the blood pressure measuring site A pulse wave detection air bag (pulse wave detection cuff) that lays on the blood pressure measurement site of the ischemic air bag and contacts the blood pressure downstream side of the blood pressure measurement site and detects a pulse wave generated on the downstream side. ) and the cuff body configured from a pressurization means connected via a pipe and a switching valve for applying moderate the cuff body, pressure of the air bag the said air bag for detecting pulse waves avascularization cuff pressure test to obtain the cuff pressure signal from the change Means, and pulse wave detecting means for obtaining a pulse wave signal by detecting a pulse wave superposed on the cuff pressure signal, and blood pressure determining means for determining a blood pressure value based on the cuff pressure signal and the pulse wave signal, wherein Display means for displaying a blood pressure value, and the pipe includes a first pipe connected via a first opening / closing valve between the blood- blocking air bag and the pressure- increasing / decreasing means, the sub-air bag, and the a second pipe connected through a second on-off valve between the pressure regulating means, a third pipe that connects the cuff pressure detecting means and said air bag for detecting pulse waves via the third on-off valve the provided, between the third pipe connected to the air bag for detecting pulse waves from the first pipe connected to the air bag wherein the ischemia is provided with a bypass flow path comprising a first fluid resistance, the Before pressurizing the air bag for ischemia and the air bag for detecting the pulse wave, the first opening / closing bar And the third open / close valve are closed, the second open / close valve is opened and the sub air bag is pressurized to a specified pressure, then the second open / close valve is closed, and the air amount of the sub air bag is The second on-off valve is closed while adjusting the pressure and measuring the blood pressure.

  The second open / close valve is opened at the end of blood pressure measurement or before the start of blood pressure measurement to exhaust the air in the sub air bag to the outside.

  Further, the first on-off valve, the second on-off valve, and the third on-off valve are electromagnetic valves.

  Further, an air tank is connected to the third pipe.

A cuff member that is detachably attached to the blood pressure measurement site; an air bag for ischemia that is included in the cuff member and compresses the blood pressure measurement site; and a blood pressure measurement site of the air bag for ischemia A sub-air bag (sub-cuff) that is laid on the opposite side to the side in contact with the heart side of the blood pressure measurement site and assists the compression of the air bag for ischemia, and a pipe and an open / close valve for increasing and decreasing the pressure of the cuff member obtaining a pressurizing and depressurizing means is SeMMitsuru, the cuff pressure detecting means for obtaining a cuff pressure signal from the pressure change of the air bag the ischemia, the pulse wave signal by detecting a pulse wave superposed on the cuff pressure signal And a blood pressure determining means for determining a blood pressure value based on the cuff pressure signal and the pulse wave signal, and a display means for displaying the blood pressure value, and the piping includes the air bag for ischemia And a first on-off valve between the pressure increasing / decreasing means A first pipe connected via the second air bag, a second pipe connected between the sub air bag and the pressure increasing / decreasing means via a second on-off valve, a pulse wave detecting air bag, and the cuff pressure detecting means. A third pipe that connects the first and second open / close valves with the third open / close valve, and before closing the air bag for pressurization, the first open / close valve and the third open / close valve are closed. , after the sub air bag is opened the second on-off valve is pressurized to a specified pressure, closing the second閉閉valve to adjust the air volume of the sub air bag, and measuring blood pressure During this time, the second open / close valve is closed.

According to the present invention, even in Daburukafu method was present, the cuff upstream portion (heart side than the central portion of the artery running direction of the measuring portion of ischemia air bag) when the cuff pressure is higher than the systolic blood pressure Pulse waves generated by blood flow entering and exiting in synchrony with the contraction and expansion of the heart are used for ischemia by reinforcing the upstream end of the air bag for ischemia with a sub-air bag and pressing from the outside of the air bag for ischemia upstream Kafuejji effect is reduced because down to near the edge of the air bag can compress the blood vessels at the same pressure as the central portion of the air bag.

  Embodiments of the present invention will be described below with reference to the accompanying drawings, but the present invention is not limited to the embodiments.

  FIG. 1 is a block diagram showing a blood pressure measurement device according to one embodiment of the present invention and a diagram showing air piping. In this figure, the cuff body 1 includes a cloth cuff member 2 that is detachably provided to a blood pressure measurement site including the upper arm, forearm, thigh, and lower limbs. A male (hook type) surface fastener 3 shown by a broken line is provided at the end portion on the contact side, and a female (loop type) surface fastener 4 is provided on the opposite side of the end portion from the side in contact with the measurement site. As shown in the figure, the cuff member 2 is wound around the measurement site so that the hook-and-loop fasteners are locked, so that the cuff body 1 can be mounted and removed by releasing the locking state. It is configured.

  The size of the fastener is such that the hook-and-loop fastener 4 is slightly longer than the air bag 8 for blocking blood (the cuff for blood blocking), and the hook-and-loop fastener 3 is wound around the arm having the maximum measurable arm circumference length. The length is set to sufficiently cover the surface fastener 4. Here, the hook-and-loop fastener is merely an example, and other members may be used, or a method of forming a cylinder and inserting an arm may be used.

  Inside the cuff member 2, a hemostatic air bag 8 shown by a broken line for squeezing the entire blood pressure measurement site is laid (included). The blood-insufficiency air bag 8 is connected to a pump 23 and an electromagnetic orifice diameter control valve 22 which are pressure-increasing / decreasing means via a first pipe 12 made of a soft tube via a first on-off valve 15-2. External air is introduced through the opening 23a of the pump 23 to pressurize it, and the opening of the orifice diameter of the electromagnetic orifice diameter control valve 22 is controlled to exhaust air from the opening 22 at a constant pressure reduction rate. It can be decompressed.

  In addition, on the side of the blood bladder 8 that contacts the blood pressure measurement site, the cuff downstream side of the arterial blood vessel of the blood pressure measurement site is pressed to detect a pulse wave (pulse wave detection cuff). ) 5 is laid with a backing member 6 interposed. A third pipe 11 made of a soft tube is connected to the pulse wave detection air bag 5 via a third opening / closing valve 15-1. A fluid resistance 14 made of a thin tube is connected between the first pipe 12a and the third pipe 11a. In addition, a sub-air bag (sub-cuff) 7 shown in a broken line is formed on the upstream side (heart side) of the ischemic air bag 8 to narrow the width in order to reduce the cuff edge effect on the heart side of the blood pressure measurement site. A backing member 9 is sandwiched between the air bag 8 and the sub air bag 7 and is laid on the side opposite to the side in contact with the measurement site. A second pipe 13 made of a soft tube is connected to the sub air bag 7, and the first pipe 12a and the pressure increasing / decreasing means are connected via a second opening / closing valve 16 and a second pipe 13a for opening and closing the pipe path. They are connected as shown.

The first pipes 12, 12 a, the second pipes 13, 13 a, and the third pipes 11, 11 a are provided by the connector 10 so as to be detachable from the main body 30. In the drawing, the connector 10 is configured to be detachable, but an integrated pipe may be used. The fluid resistance 14 has a function of restricting the entry and exit of air into and from the pulse wave detection air bladder 5. Further, in order to obtain the cuff pressure value signal of the air bag 8 for ischemia and the pulse wave signal of the air bag 5 for detecting the pulse wave, the air bag 8 for ischemia has the first pipes 12 and 12a, the fluid resistance 14, the third pipe 11a, is connected to the pressure sensor 31 is a cuff pressure detecting means, while the pressure sensor 31 is the air bag 5 for pulse wave detection cuff pressure detecting means by the third pipe 11,11a It is connected to the.
Pressure measuring unit 32 to limit the amplification and frequency band converted signal into an electric signal is connected with the pressure sensor 31. Further, an A / D converter 33 that converts an analog electric signal into a digital signal is connected, and the digital signal is output to the central control unit 35.

The central control unit 35 includes a RAM 36 capable of writing and reading data, and includes a pulse wave processing unit 38 including a pulse wave detection means for obtaining a pulse wave signal superimposed on the cuff pressure signal, cuff pressure processing unit 39 includes a pressure reducing means, the blood pressure measuring unit 40 including a blood pressure detecting means for determining a blood pressure value from the pressure values and the pulse wave signal change ischemia air bag, and a display control unit 41 for displaying the measurement result It is configured as shown. The control program of the central control unit 35 is built in the ROM. Furthermore, the central control unit 35 includes a display unit 37 that is a blood pressure display unit that displays a blood pressure value, a pump drive unit 48 that controls the drive of the pump 23, and a valve control that controls the opening and closing of the second open / close valve 16. A part 46, an electromagnetic orifice diameter control valve control part 48 for controlling the electromagnetic orifice diameter control valve 22, a valve control part 47 for opening / closing the first opening / closing valve 15-2 and the third opening / closing valve 15-1, and a dry battery. The power supply unit 43 including the power supply switch 42 is connected.

  In the above configuration, when the power switch 42 is turned on, power is supplied from the power supply unit 43, the contents of the program stored in the ROM are read, and each control necessary for blood pressure measurement can be performed. It is configured as follows.

  The cuff body 1 configured as described above can be used for various blood pressure measuring devices. For example, the blood pressure measurement device shown in FIG. 1 can be operated as shown in the flowchart of the blood pressure measurement routine in FIG. 2 by reading out a control program stored in advance by the central control device.

First, the blood pressure measurement device is activated by turning on the power switch 42. In step ST1, the first on-off valve 15-2, the second on-off valve 16, and the third on-off valve 15-1 are opened. Also, by the electromagnetic orifice diameter control valve 22 at step ST2 in the open state, residual pressure in all the cuff, the residual air is exhausted, performing zero setting of the pressure sensor 31 in the absence of residual pressure (step ST3). Next, in step ST4, the first opening / closing valve and the third opening / closing valve are closed, and the electromagnetic orifice control valve 22 is fully closed.

In the next step ST5, the pump 23 is activated. Then, whether the sub air bag Kafuejji effect of ischemia air bag 8 becomes the specified pressure force is suitable pressures are Keimetsu in step ST6 it is determined. If it is determined that becomes the specified pressure force to close the second on-off valve proceeds to step ST7. Then, in step ST8, the pressurization of the air bag 8 for the ischemia and the air bag 5 for detecting the pulse wave is started by opening the first open / close valve and the second open / close valve.

Further, with respect to ischemia bladder 8 and the pulse wave detection air bag 5 to approximately 40mmHg higher by about pressure than systolic blood pressure that is expected is set in advance in step ST9, the flow resistance suppress airflow 16 Blow air through. When the set pressure is detected in step ST9, the energization to the pressurizing pump 23 is turned off in step ST10. In step ST11, the electromagnetic orifice diameter control valve 22 starts depressurization at a depressurization speed of 2 to 3 mmHg / sec. Obtaining a cuff pressure from the cuff pressure detecting unit in step ST12 subsequent to this. In step ST13 to start the detection of the pulse wave. The amplitude of the pulse wave detected in step ST14 and the cuff pressure when detected are paired and stored in the RAM 36 in time series. After detecting the maximum value of the pulse wave amplitude in step ST15, for example, the amplitude specified value or more is detected a sudden small point, detects the cuff pressure value at that time as the diastolic pressure, stored in the RAM36 To do. In step ST16, the electromagnetic orifice diameter control valve and the second opening / closing valve are fully opened to exhaust to atmospheric pressure. Also, retrieves the oldest measurement start time of the time pairs of pulse wave amplitude and the cuff pressure value stored in the time series at step ST17 in the RAM 36, the pulse wave amplitude suddenly to more than 50% stepwise detecting a point at which increased, it is stored in the RAM36 the cuff pressure value at that time as systolic blood pressure. The systolic blood pressure value and the diastolic blood pressure value stored in step ST18 are displayed on the display unit 37, and the series of blood pressure measurement assistance is completed.

  Although the above control method demonstrated the suitable Example of the blood-pressure measuring apparatus of this invention, this invention is not limited to these.

As described above, the pulse wave amplitude cuff pressure occurs when higher than systolic blood pressure can be reduced, the pulse wave output of beats cuff distal generated when the cuff pressure is lower than the systolic blood pressure S Since the / N ratio can be detected for detection, the measurement accuracy of systolic blood pressure is greatly improved. The cuff edge effect is greatly affected by the amount of air in the sub-air bag. However, if the sub-air bag is pressurized too much, the vascular pressure is too strong and the pulsed pulse wave becomes weak. It will be measured low. However, if the pressure is insufficient, the cuff edge effect cannot be sufficiently reduced. Accordingly, the first on-off valve, the third opening and closing valve, the second on-off valve allows optimum pressure control of the sub air bladder by opening and closing control as described above results, the sub air bag optimal pressurization value Can be pressurized. For this reason cuff upstream pulse wave cuff pressure becomes impaired systolic blood pressure measurement is higher than the systolic blood pressure, can now be smaller than Daburukafu method. In addition, by using electromagnetic bypass valves as the first open / close valve, second open / close valve, and third open / close valve, the piping can be made compact and the drive control can be easily performed, so a small blood pressure measuring device is realized. It has become possible. In addition, by connecting an air buffer tank (not shown) to the pulse wave detection air bag, the phenomenon that the pulse wave upstream of the cuff is detected by the pulse wave detection unit via the air bag is reduced. The S / N ratio of the systolic blood pressure measurement was improved.

It is a block diagram which shows the blood pressure measuring device of one Embodiment of this invention. , 2 is an operation explanatory flowchart of the blood pressure measurement device in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cuff body 2 Cuff member 8 Air bag 7 for ischemia Sub air bag 5 Air bag 15 for pulse wave detection First open / close valve 16 Second open / close valve 15-1 Third open / close valve 23 Pump (pressurizing / depressurizing means)
31 Pressure sensor (cuff pressure detection means)
11, 11a First piping 12, 12a Second piping 13, 13a Third piping 14 Fluid resistor 22 Orifice diameter variable solenoid valve

Claims (5)

A cuff member provided detachably with respect to the blood pressure measurement site;
An air bag for ischemia that is contained in the cuff member and compresses the blood pressure measurement site;
A sub-air bag that is laid on the opposite side of the blood pressure measurement site of the blood bag for blood pressure measurement and that assists the compression of the air bag for blood pressure measurement on the heart side of the blood pressure measurement site;
The ischemia for laid on the side in contact with a blood pressure measurement site of the air bag pressure on the blood vessel downstream of the blood pressure measurement portion, and the air bag for detecting pulse waves for detecting a pulse wave generated in the downstream side consists of a cuff The body,
Pressurizing and depressurizing means connected via a pipe and an open / close valve to pressurize and depressurize the cuff body;
A cuff pressure detecting means for obtaining a cuff pressure signal from the pressure change of the air bag the said air bag for detecting pulse waves ischemia,
Pulse wave detection means for detecting a pulse wave superimposed on the cuff pressure signal to obtain a pulse wave signal;
Blood pressure determining means for determining a blood pressure value based on the cuff pressure signal and the pulse wave signal;
Display means for displaying the blood pressure value ,
The piping is
A first pipe connected via a first on-off valve between the blood-insufficating air bag and the pressure-increasing / decreasing means;
A second pipe connected via a second on-off valve between the sub air bag and the pressure-increasing / decreasing means;
A third and pipe, which connects the said air bag for detecting pulse waves cuff pressure detecting means via a third on-off valve,
Between the first pipe connected to the air bag for ischemia and the third pipe connected to the air bag for pulse wave detection is provided with a bypass flow path consisting of a first fluid resistance,
Before pressurizing the air bag and the air bag for detecting pulse waves for the ischemia, the first on-off valve is closed and said third on-off valve, the sub air bag specified pressure by opening the second on-off valve The second open / close valve is closed while the second open / close valve is closed, the amount of air in the sub air bag is adjusted, and the second open / close valve is closed while blood pressure is measured. Blood pressure measuring device.   2. The blood pressure measurement device according to claim 1, wherein the second open / close valve is opened at the end of blood pressure measurement or before the blood pressure measurement is started to exhaust air in the sub-air bag.   The blood pressure measuring device according to claim 1, wherein the first on-off valve, the second on-off valve, and the third on-off valve are electromagnetic valves.   The blood pressure measuring device according to claim 1, wherein an air tank is connected to the third pipe. A cuff member provided detachably with respect to the blood pressure measurement site;
An air bag for ischemia that is contained in the cuff member and compresses the blood pressure measurement site;
A sub-air bag that is laid on the opposite side of the blood pressure measurement site of the blood bag for blood pressure measurement and that assists the compression of the air bag for blood pressure measurement on the heart side of the blood pressure measurement site;
Pressurizing and depressurizing means connected via a pipe and an open / close valve to pressurize and depressurize the cuff member;
A cuff pressure detecting means for obtaining a cuff pressure signal from the pressure change of the air bag the ischemia,
A pulse wave detecting means for obtaining a pulse wave signal by detecting a pulse wave superposed on the cuff pressure signal,
And blood pressure determining means for determining a blood pressure value based on the cuff pressure signal and the pulse wave signal,
Display means for displaying the blood pressure value ,
The piping is
A first pipe connected via a first on-off valve between the blood-insufficating air bag and the pressure-increasing / decreasing means;
A second pipe connected via a second on-off valve between the sub air bag and the pressure-increasing / decreasing means;
A blood pressure measuring device comprising: a third piping for connecting a pulse wave detecting air bag and the cuff pressure detecting means via a third on-off valve ;
Wherein the ischemic air bag before pressurizing, closed and said third on-off valve and the first on-off valve, after the sub air bag is opened the second on-off valve is pressurized to a specified pressure, wherein The blood pressure measuring device, wherein the second on-off valve is closed while the second closing valve is closed, the amount of air in the sub air bag is adjusted, and the blood pressure is measured.

Images