JPH082348B2 - Automatic blood pressure measurement device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic blood pressure measurement device, and more particularly to a technique for measuring blood pressure when an abnormality occurs in circulatory dynamics of a living body.

2. Description of the Related Art There is known an automatic blood pressure measurement device that automatically measures a blood pressure value of a living body based on a change in the magnitude of a pulse synchronization wave that is obtained with a change in the compression pressure of a part of the living body. Such a blood pressure value is an important index for diagnosing the circulatory dynamics of a living body, but in order to make the diagnosis of the circulatory dynamics more reliable, it is possible to continuously measure the blood pressure at a predetermined time using the above device. Has been done.

Problems to be Solved by the Invention However, even if the blood pressure is continuously measured at predetermined time intervals, if an abnormality occurs in the circulatory dynamics of the living body between each blood pressure measurement cycle, the blood pressure at the time of the abnormality occurs. There was a problem that the values could not be measured and the hemodynamics could not be accurately diagnosed.

Means for Solving the Problems The present invention has been made in view of the above circumstances, and the gist thereof is an automatic blood pressure device as described above, which comprises (a) It includes a pulmonary ventilation abnormality detecting means for detecting an abnormality in lung ventilation, and (b) blood pressure measurement starting means for starting blood pressure measurement when the abnormality in lung ventilation is detected by the abnormality detecting means for lung ventilation.

In this way, the pulmonary ventilation abnormality detecting means detects the pulmonary ventilation abnormality of the living body, and when the pulmonary ventilation abnormality is detected, the blood pressure measurement starting means starts the blood pressure measurement. In this case, lung ventilation abnormalities are usually
Since the abnormal circulatory dynamics are closely related to each other, the blood pressure measurement when the abnormal circulatory dynamics occur can be effectively measured by starting the blood pressure measurement based on the occurrence of the abnormal pulmonary ventilation. This makes it possible to more accurately diagnose the circulatory dynamics of the living body as compared with the conventional case.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 10 is a rubber bag-like cuff that is wound around the upper arm of the subject. Cuff 10 has a pressure sensor 1
2, air pump 14, throttle 16 for deceleration exhaust and solenoid valve 1
8. A solenoid valve 20 for rapid exhaust is connected to each other via a pipe 22. The pressure sensor 12 supplies a pressure signal SP representing the pressure in the cuff 10 to the static pressure discrimination circuit 24 and the pulse wave discrimination circuit 26, respectively. The static pressure discrimination circuit 24 is equipped with a low-pass filter, discriminates the cuff pressure signal SK representing the steady pressure contained in the pressure signal SP, and the Cuff pressure signal SK is A / D converted.
To CPU30 via. The pulse wave discrimination circuit 26 is provided with a bandpass filter, discriminates the pulse wave signal SM representing the pulse wave included in the pressure signal SP, and the pulse wave signal SM is A / D converted.
Supply to CPU30 via 8. This pulse wave constitutes the pulse synchronization wave of this embodiment and is a pressure vibration wave of the cuff 10 that is generated in synchronization with the heartbeat of the measurement subject.

CPU30, ROM34, RAM36, via the data bus line,
The air pump 14 is connected to the display unit 38 and the output interface 40 and executes signal processing while utilizing the storage function of the RAM 36 according to a program predetermined in the ROM 34.
And control both solenoid valves 18, 20. Further, the CPU 30 executes a series of blood pressure measurement operations to determine a systolic blood pressure value, a diastolic blood pressure value, an average blood pressure value, etc. based on the pulse wave signal SM, the cuff pressure signal SK, etc. Is displayed on the display unit 38. The detailed description of the blood pressure measurement operation is omitted because it is not necessary for understanding the present invention.

The CPU30 is further connected to the measurement start switch 42, and the potentiometer 44 is connected via the A / D converter 46, and the measurement start switch 42 is based on the start signal SS output from the CPU30. Controlled. The potentiometer 44 is one whose output voltage is changed in response to a change in the volume of a chamber 58 of the respirometer 48, which will be described later. The potentiometer 44 converts the ventilation signal CS representing the pulmonary ventilation state of the measurement subject to the A / D converter 46. Supply to CPU30 via. The potentiometer 44 may be either a rotary type or a linear type, but since it is well known, detailed description thereof will be omitted.

The respirometer 48 has an outer peripheral wall 50 as shown in FIG. 2, for example.
And a lower tubular member 56 in which a liquid such as water is contained in an annular groove between the inner peripheral wall 52 and the inner peripheral wall 52, and a bottomed cylindrical member, with the open end side being inserted into the liquid. The lower tubular member 56 is provided so as to be movable relative to the tubular member 56 in the axial direction.
And an upper tubular member 60 that forms an airtight chamber 58 with a variable volume therebetween. One end of the breathing guide tube 62 is connected to the chamber 58, and the other end of the expiratory guide tube 62 is connected to the mouthpiece 68 together with the inspiratory tube 64 via one-way valves (not shown). As a result, inspiration is performed from the atmosphere through the inspiratory tube 64, while expiratory air is introduced into the chamber 58 through the expiratory inducing tube 62, and the upper tubular member 60 is moved to the upper tubular member 60 in accordance with the expiratory volume. The volume of the chamber 58 is increased by moving the space upward. Room
An electromagnetic valve 70 and a suction pump 72 are further connected to 58, and the electromagnetic valve 70 and the suction pump 72 are controlled by a drive signal (not shown) output from the CPU 30. This solenoid valve 70 is closed in the exhaled state of the person to be measured, but opened in the inhaled state, so that the suction pump during the inhalation period in which the chamber 58 whose volume has increased due to the exhalation continues thereafter. It is designed to be aspirated by 72 and returned to its pre-expired volume. As a result, the vertical movement of the upper tubular member 60 is repeated with the breathing of the person to be measured, and the moving distance of the upper tubular member 60, that is, the volume change amount of the chamber 58 is the potentiometer.
Detected by 44. The upper tubular member 60,
A balance weight (not shown) of a predetermined weight is provided to urge it upward in FIG. 2, and this reduces the resistance during expiration.

Next, the operation until the blood pressure measurement is started by the automatic blood pressure measurement device configured as described above will be described according to the flow chart in FIG. In the present embodiment, the presence or absence of abnormal pulmonary ventilation is detected during normal tidal breathing of the subject.

When the power is turned on, the initial process of step S1 is executed and step S2 is executed to execute the ventilation signal CS.
Is read. Next, by executing step S3, it is determined whether or not one exhalation has ended. If this determination is negative, steps S2 and S3 are repeatedly executed, but if the determination of step S3 is positive, the following step S4 is executed and the minimum of each ventilation signal CS read in step S2. The tidal volume is calculated based on the difference between the maximum value and the maximum value. Next, when step S5 is executed, it is determined whether or not pulmonary ventilation abnormality has occurred by comparing the tidal volume determined in step S4 with a predetermined reference ventilation volume. The standard ventilation volume is appropriately changed depending on the person to be measured. If it is determined in step S5 that no pulmonary ventilation abnormality has occurred, steps S2 to S5 described above are repeatedly executed, but if it is determined that pulmonary ventilation abnormality has occurred, the following step S6 is executed. Is the start signal SS
The measurement start switch 42 is closed by this, and thereby blood pressure measurement is started according to a blood pressure measurement routine (not shown). Therefore, in the present embodiment, the respirometer 48, potentiometer 44, A / D converter 46, and step S5 and the like correspond to pulmonary ventilation abnormality detection means, and the measurement start switch 42 and step S6 and the like are blood pressure measurement start means. Equivalent to.

As described above, according to the present embodiment, blood pressure measurement is started when pulmonary ventilation abnormality is detected, which is closely related to the abnormal circulatory dynamics of the measurement subject, so that blood pressure measurement is simply repeated at predetermined time intervals. The blood pressure value at the time of occurrence of abnormal circulatory dynamics can be more reliably measured as compared with the conventional case. As a result, the circulatory dynamics of the subject can be diagnosed more accurately than in the conventional case.

In the above-described embodiment, the abnormal lung ventilation is determined based on the tidal volume during tidal breathing. However, in addition to or instead of this, the unit time (1
Abnormal lung ventilation may be determined based on other lung ventilation such as ventilation per second (1 minute).

Further, in the above-described embodiment, the blood pressure is measured only once when the pulmonary ventilation abnormality is detected, but this is not always necessary. The blood pressure measurement may be continuously repeated for each occurrence of pulmonary ventilation abnormality while continuously detecting over time, or the blood pressure measurement may be continuously performed at predetermined time intervals in the same manner as in the past, and in addition to pulmonary ventilation. The blood pressure may be further measured when an abnormality occurs.

Further, the pulmonary ventilation abnormality detecting means is configured to have a predetermined gas analyzer in addition to or instead of the respirometer 48 as in the above-mentioned embodiment, so that each oxygen in inhalation and exhalation is measured. The abnormality in lung ventilation may be detected based on the oxygen consumption amount and the carbon dioxide concentration in exhaled air obtained based on the difference in concentration. In this case, the oxygen concentration and the carbon dioxide concentration will be measured based on end inspiration and end expiration.

Further, the lung ventilation abnormality detecting means may be configured to include a so-called body volume meter that measures a change in body volume associated with respiratory movement.

Further, the pulmonary ventilation abnormality detecting means may detect the pulmonary ventilation abnormality based on measuring the respiratory rate per predetermined time.

Further, the lung ventilation abnormality detecting means may detect the lung ventilation abnormality based on a respiratory waveform measured by a predetermined respirometer or the like.

Further, in the above-described embodiment, the case where the present invention is applied to the so-called oscillometric automatic blood pressure measuring apparatus that adopts the pulse wave as the pulse synchronization wave is described, but the present invention uses the Korotkoff sound as the pulse synchronization wave. So-called K to use
Of course, it can be applied to other automatic blood pressure measuring devices such as a sound system.

Besides, the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control circuit of an automatic blood pressure measuring device to which the present invention is applied. FIG. 2 is a schematic view showing an example of the respirometer of FIG. 1, and is a view showing a part of it in section. FIG. 3 is a flow chart for explaining the operation of the apparatus of FIG. 1, and is a view showing a flowchart until the blood pressure measurement is started. 42: Measurement start switch 44: Potentiometer 46: A / D converter 48: Respirometer

Claims (3)

[Claims] 1. An automatic blood pressure measuring device for automatically measuring a blood pressure value of a living body based on a change in the magnitude of a pulse synchronization wave obtained with a change in the compression pressure of a part of the living body, the lung of the living body. An automatic blood pressure measuring device comprising: a pulmonary ventilation abnormality detecting means for detecting a ventilation abnormality; and a blood pressure measurement starting means for starting a blood pressure measurement when the lung ventilation abnormality detecting means detects a pulmonary ventilation abnormality. 2. The automatic blood pressure measuring device according to claim 1, wherein the pulmonary ventilation abnormality detecting means has a respirometer for measuring a predetermined lung ventilation volume. 3. The automatic blood pressure measuring device according to claim 1, wherein the pulmonary ventilation abnormality detecting means has a gas analyzer for measuring the concentration of a predetermined gas in respiratory air.