JPS633835A - Blood pressure measuring apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an improvement in a blood pressure measuring device that measures blood pressure values based on changes in pulse waves obtained by compressing a part of a living body.

Problems to be solved by the prior art and the invention - In general, blood pressure values are measured based on changes in pulse waves obtained from a part of a living body in synchronization with the heartbeat while changing compression pressure on that part of the living body. Blood pressure measuring devices are known.

In such a device, blood pressure measurement is performed by changing the compression pressure on a part of the living body regardless of whether the detected pulse wave is correct or not, so if the detected pulse wave is noise due to body movement, etc. Since accurate blood pressure values are not measured, it is necessary to compress a part of the living body again, detect a normal pulse wave, and re-measure, which is troublesome and does not provide sufficient measurement reliability. there were.

First Means for Solving the Problems The present invention has been made against the background of the above circumstances, and its gist is that, as shown in the claim correspondence diagram in FIG. A blood pressure measuring device equipped with a blood pressure value determining means that determines the blood pressure value based on changes in pulse waves obtained from a part of the living body in synchronization with the heartbeat while changing the compression pressure of a cuff wrapped around the body. (a) pulse wave detection means for detecting a pulse wave based on pressure vibrations of the cuff; (b)
a pulse wave determining means for determining whether or not the pulse wave detected by the pulse wave detecting means is normal; However, when a normal pulse wave is determined, the cuff pressure release means increases the compression pressure of the cuff by a predetermined constant value.

Operation and Effect of the First Invention In this way, the compression pressure on a part of the living body is maintained until the pulse wave determination means determines that a normal pulse wave has been collected; When it is determined that the compression pressure has been collected, the compression pressure is increased by a predetermined constant value by the compression pressure release means. Therefore, according to the present invention, only normal pulse waves are detected during the process of increasing compression pressure on a part of the living body, so that accurate blood pressure measurement is always performed and the reliability of the measurement results is improved. In this case, if an erroneous pulse wave is detected and an erroneous blood pressure measurement is performed based on the detected pulse wave, there is no need to take the trouble of measuring the blood pressure again.

Furthermore, according to the present invention, since the cuff pressure is maintained and constant when collecting pulse waves, the collected pulse waves are accurate without being distorted, so that the measured blood pressure values are even more accurate. It will become.

Second Means for Solving the Problems Another aspect of the present invention is, as shown in the claim correspondence diagram of FIG. A blood pressure measuring device comprising a blood pressure value determining means for determining a blood pressure value based on a change in a pulse wave obtained from a part of the living body in synchronization with a heartbeat while changing compression pressure,
(a) pulse wave detection means for detecting a pulse wave based on pressure vibrations of the cuff; and fb) pulse wave determination means for determining whether the pulse wave detected by the pulse wave detection means is normal. ,
tc) The compression pressure of the cuff is maintained until a normal pulse wave is determined by the pulse wave determining means, but when a normal pulse wave is determined, the compression pressure of the cuff is increased to a predetermined constant value. and Cd) a compression pressure release means for immediately releasing the compression pressure on the living body when the systolic blood pressure of the living body is determined by the blood pressure value determining means.

Effect of the second invention In this way, in addition to obtaining the same effect as the first invention, when the systolic blood pressure of the living body is determined by the compression pressure release means, the compression pressure on the living body is reduced. is immediately released, which has the advantage of eliminating unnecessary pressure on the living body.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, a cuff 10 that is equipped with an air bag and has a belt shape and is wrapped around the upper arm of a living body includes a pressure sensor 12, an on-off valve 14, a tank 15, a quick exhaust valve 16, and an electric pump 18. are connected to each other via air piping 20. The tank 15 is provided to remove pulsating components included in the output pressure of the electric pump 18, and is provided with a throttle on its input side and/or output side, if necessary. Pressure sensor 12 detects the pressure within cuff 10 and outputs a pressure signal SP representing the pressure to pulse wave detection circuit 22 and cuff pressure detection circuit 24. The pulse wave detection circuit 22 is equipped with a bandpass filter in the cafe 0 that passes signals in a frequency band constituting a pulse wave, which is a pressure vibration generated in synchronization with the heartbeat of a living body, and includes a bandpass filter that passes signals in a frequency band constituting a pulse wave, which is a pressure vibration generated in synchronization with the heartbeat of a living body. A/D converter 2 extracts only the pulse wave
Supply to 6. Further, the cuff pressure detection circuit 24 includes a low-pass filter, extracts a signal representing the static pressure component of the cuff 10 included in the pressure signal SP, and supplies it to the A/D converter 26 . The A/D converter 26 converts each input analog signal into a digital signal and supplies the digital signal to the CPU 28. In this embodiment, the pressure sensor 12, pulse wave detection circuit 22, etc. function as pulse wave detection means for detecting pulse waves.

The CPU 28 constitutes a microcomputer together with the RAM 30 and the ROM 32.
Processing the input signal according to a program stored in advance in the ROM 32 while utilizing the temporary memory function of 0, and controlling the on-off valve 14, rapid exhaust valve 16, and electric pump 18 to automatically execute blood pressure measurement, The obtained blood pressure value is displayed on the display 3.
Display the number on 4.

The operation of this embodiment will be explained below with reference to the flowcharts of FIGS. 2 and 3.

In FIG. 2, first, step S1 is executed to determine whether or not the start push button 36 has been operated, that is, whether or not measurement has been started.

If it is determined that it has been operated, step S3 is executed, but if it is determined that it has not been operated, it is determined in step S2 whether or not a start signal for automatic measurement has been input. This automatic measurement start signal is supplied periodically from a start signal generation circuit (not shown), for example, every 10 minutes. If it is determined that the automatic measurement activation signal has not been input, the process returns to step S1, but if it is determined that the automatic measurement activation signal has been input, the subsequent step S3 is executed. In step S3, the quick exhaust valve 1
6 is closed, in step S4, the on-off valve 14 is opened and the electric pump 18 is started, thereby supplying pressure from the electric pump 18 into the cuff 10 and increasing the pressure of the cuff 10. In the subsequent step S5, the actual pressure of the cuff 10 that has been increased is determined to be a predetermined preliminary cuff pressure, that is, a pressure that is sufficiently lower than the expected diastolic blood pressure value of the subject and that is sufficient to detect a pulse wave. (10～
15 mHg) is reached. If it is determined that the point has not been reached, steps 83 and subsequent steps are repeated, but if it is determined that the point has been reached, the subsequent step S6 is executed to close the on-off valve 14 and stop the operation of the electric pump 18. Ru.

In the subsequent step 87 and subsequent steps, the cuff 1 as described above is
During the pressure increase process at 0, the blood pressure value is determined based on changes in the pulse wave obtained in synchronization with the heartbeat. That is, by executing step S7, it is determined whether a pulse wave has been detected. If it is determined that a pulse wave has not been detected yet, steps 83 and subsequent steps are repeatedly executed, but if it is determined that a pulse wave has been detected, in step S8,
It is determined whether the detected pulse wave is correct or not.

In other words, when two consecutive pulse waves are detected, if the two pulse waves have the same magnitude (amplitude value), it is determined that the pulse wave is normal; If the pulse waves are different, it is determined that these pulse waves are not normal, so the compression pressure of the cuff 10 is maintained and a wait is made until two successive pulse waves of the same magnitude are detected. For example, Fig. 4(a) and ('b)
As shown in the figure, when a pulse wave B, which is a pulse wave different in magnitude from the A wave, is detected following the A wave, it is determined that these A waves and B waves are not normal pulse waves, and the cuff 10 is compressed. Although the pressure is maintained, a pulse wave C wave having the same magnitude as the B wave is detected following the B wave, and at the same time, the C wave is determined to be a normal pulse wave. Therefore, the ROM 32 in which a program for executing step S8 is stored in advance, the CPU 28 and RAM 30 that execute this program correspond to the pulse wave determining means of this embodiment.

As described above, each time a pulse wave is detected in step S8, it is determined whether the pulse wave is normal or not, and only normal pulse waves are recognized and stored. Subsequently, the blood pressure value determination routine of step S9 shown in FIG. It is determined whether the blood pressure value obtained is the systolic blood pressure value. In this embodiment, basically, the lowest and systolic blood pressure values are determined at locations where the rate of change in the magnitude of the pulse wave is large, and step S9 corresponds to the blood pressure value determination means of this embodiment. It is something. Since the initial pressure is not the systolic blood pressure value, the next scheduled pressure rise value is determined by adding a predetermined pressure rise range to the current cuff pressure in step Sll, and the on-off valve 14 is opened in step S12. By activating the electric pump 18, the pressure of the cuff 10 is increased.
The value is about 5 mHg, and the overall value is 2 to 3 mHg.
It is possible to obtain a pressure increase rate of about Hg/sec. However, the boost width may not be a constant value, but may be a variable value so that an ideal boost rate can be obtained as a whole.

Subsequently, step S13 is executed, and it is determined whether the cuff pressure value of the cuff 10 has reached the expected pressure increase value determined in step Sll. If it is determined that the pressure has not yet reached the planned pressure increase value, steps 312 and subsequent steps are repeated. However, if it is determined that the planned pressure increase has been reached, the on-off valve 14 is closed and the electric pump 18 is activated in step S14. is stopped, and a new pulse wave is immediately detected. That is, the R in which the program for executing step S12 and step S13 is stored
The OM 32, the CPU 28 that executes the program, and the RAM 30 correspond to the compression pressure release means of this embodiment.

Next, step S8 is executed again to newly recognize a normal pulse wave, and the operations of steps S8 to S14 described above are repeatedly executed until the systolic blood pressure value is determined.

When it is determined in step SIO that the systolic blood pressure value has been determined, step S15 is executed, and the diastolic blood pressure value, mean blood pressure value, and pulse wave are calculated based on the determined systolic blood pressure value. As it is decided,
Subsequent step S16 is executed, and the systolic blood pressure value, diastolic blood pressure value, average blood pressure value, and pulse wave are displayed on the display 34.

Then, in step S47 for implementing the compression pressure release means of this embodiment, the rapid exhaust valve 16 is opened, so that the air within the cuff 10 is rapidly exhausted, and the measurement of the blood pressure value is completed.

As described above, according to this embodiment, only the pulse wave determined to be normal in step S8 is recognized, and if an erroneous pulse wave such as noise caused by body movement or the like is detected, the pulse wave is recognized. The system waits until a normal pulse wave is recognized, and the blood pressure value is determined based only on such a normal pulse wave. Therefore, according to this embodiment, even if noise due to body movement etc. is mixed in, an accurate blood pressure value can always be obtained based on a normal pulse wave in a single blood pressure measurement, thereby improving the measurement result. This improves the reliability of blood pressure and eliminates the trouble of remeasuring blood pressure after it has been measured based on an incorrect pulse wave. Furthermore, according to this embodiment, the cuff pressure is always constant while the pulse wave is being determined, so the detected pulse wave is not distorted and the measured blood pressure value is more accurate. It is.

Furthermore, when the systolic blood pressure value is determined, the compression by the cuff 1O is immediately relieved, which has the advantage of preventing unnecessary pressure on the subject and shortening the measurement time.

Although one embodiment of the present invention has been described above in detail based on the drawings, the present invention can also be suitably implemented in other embodiments.

For example, in the embodiment described above, the correctness or inadequacy of a pulse wave was determined by comparing the magnitudes of two consecutive pulse waves. It's also good.

In addition, in the embodiment described above, when determining whether the pulse waves are correct or not in step S8, it is recognized as a normal pulse wave when two successive pulse waves have the same size. Conditions for determining pulse waves include, for example, when two or more consecutive pulse waves detected have the same rise time, or when two or more consecutive pulse waves have the same rising slope, or when two or more consecutive pulse waves are detected at the same angle. A case may be used in which the interpulse time between three or more pulse waves is the same length,
Further, any one or a combination of all of these may be used.

Further, in the embodiment described above, the electric pump 18 was used to increase the pressure of the cuff 10, but a cylinder may be used instead of the electric pump 18.

In this case, there is an advantage that it is not necessary to provide the tank 15 for preventing transmission of the pulsation of the electric pump 18.

Furthermore, in the embodiment described above, the electric pump 18 was switched to the ON-OFF state when controlling the compression pressure of the cuff 10, but the electric pump 18 is always turned on and the on-off valve 14 is opened and closed exclusively. The compression pressure of the cuff 10 may be controlled by.

The above-mentioned embodiment is merely an embodiment of the present invention, and the present invention can be modified in various ways without departing from its spirit.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating the configuration of a blood pressure measuring device that is an embodiment of the present invention. 2 and 3 are flowcharts illustrating the operation of the embodiment of FIG. 1. FIGS. 4(a) and 4(b) are time charts showing the relationships used in the operation shown in FIG. 2, respectively. FIG. 5 and FIG. 6 are diagrams showing claims correspondence diagrams of the present invention, respectively. 10: Cuff 28: CPU 30: RAM 32: ROM Applicant Nippon Kolin Co., Ltd. Figure 2

Claims (2)

[Claims] (1) Blood pressure value determination means that determines the blood pressure value based on changes in pulse waves obtained from a part of the living body in synchronization with heartbeat while changing the compression pressure of a cuff wrapped around the part of the living body. A blood pressure measuring device comprising: a pulse wave detecting means for detecting a pulse wave based on pressure vibrations of the cuff; and a pulse wave detecting means for determining whether or not the pulse wave detected by the pulse wave detecting means is normal. wave determining means; the compression pressure of the cuff is maintained until a normal pulse wave is determined by the pulse wave determining means; however, when a normal pulse wave is determined, the compression pressure of the cuff is adjusted to a predetermined value; A blood pressure measuring device comprising: compression pressure control means for increasing pressure by a constant value; (2) A blood pressure measuring device that measures blood pressure based on changes in pulse waves obtained from a part of a living body in synchronization with the heartbeat while changing the compression pressure of a cuff wrapped around the part of the living body. pulse wave detection means for detecting a pulse wave based on pressure vibrations of the cuff; pulse wave determination means for determining whether the pulse wave detected by the pulse wave detection means is normal; The compression pressure of the cuff is maintained until a normal pulse wave is determined by the wave determination means, but when a normal pulse wave is determined, the compression pressure of the cuff is increased by a predetermined constant value. A blood pressure measuring device comprising: compression pressure control means; and compression pressure release means for immediately releasing compression pressure on the living body when the systolic blood pressure of the living body is determined by the blood pressure value determining means.