JPH0333006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a blood pressure measuring device, and in particular, a blood pressure measuring device capable of non-invasively measuring blood pressure continuously for a long period of time.
This invention relates to an improvement of a blood pressure measuring device using a volume compensation method.

(Prior art) Arterial blood pressure is the most basic biological information that measures circulatory dynamics including cardiac function, and is used not only in clinical medicine and basic medicine such as physiology, but also in rehabilitation, sports medicine, industrial medicine, etc. It also plays an important role in the field.

Conventionally, the method of measuring blood pressure non-invasively involves compressing and closing the brachial artery with a cuff wrapped around the upper arm, then decompressing the cuff, and auscultating the blood vessel sounds (Korotkoff sounds). The auscultation method, which measures systolic and diastolic blood pressure by listening with a device, is widely used because of its ease of use.

However, with this auscultation method, due to the principle of measurement, the only blood pressure that can be measured is the systolic blood pressure and the diastolic blood pressure. Therefore, it is not possible to perform continuous blood pressure measurement for each heartbeat, which has been particularly desired in recent years. There were problems that made it impossible to do so.

Therefore, in order to deal with such problems,
Several blood pressure measuring devices based on the volume compensation method have been proposed in Japanese Patent No. 59-28947 and the like. That is,
These devices aim to continuously measure arterial blood pressure non-invasively, including the blood pressure curve within one heartbeat, and they measure intravascular pressure fluctuations by applying external pressure to blood vessels from outside the body. We focused on the fact that when the changes in blood volume accompanying blood volume are externally controlled and volume compensation is performed to keep the pulsating intravascular volume constant throughout the cardiac cycle, the external pressure required for this volume compensation is in equilibrium with the intravascular pressure. By measuring this external pressure, blood pressure is indirectly and continuously measured.

(Problem) By the way, when measuring blood pressure with a blood pressure measuring device based on such a volume compensation method, in order to maintain the intravascular volume at a volume corresponding to the unloaded state of the blood vessel wall, an external pressure equal to the arterial pressure must be applied. Arterial blood pressure at the areas where such measurements are taken, such as the upper arm, wrist, proximal or middle phalanges of the fingers, which is always added, usually has a minimum value of 60 to 90 mmHg in adults. On the other hand, venous blood pressure
Since the blood pressure is only 10 mmHg or less, the vein is constantly compressed during measurement, and if the measurement time becomes long, edema due to congestion on the peripheral side of the test area is induced, which limits the continuous measurement time. It had inherent problems.

Therefore, monitoring the patient's blood pressure during and after surgery or
When using such devices for long-term continuous measurements such as day and night blood pressure monitoring required in ICUs and CCUs, blood pressure measurements must be interrupted quite frequently to release external pressure in order to relieve congestion. This was necessary, and the operation was extremely troublesome.

(Solution Means) Here, the present invention has been made against the background of the above-mentioned circumstances, and is characterized by having a measurement hole into which a part of the body such as a finger is inserted, and A blood pressure measuring device comprising a compression means for compressing a part of the body inserted into the measurement hole, and applying external pressure through compression by the compression means to extract a desired blood pressure signal, wherein one of the measurement holes A tip pressurizer is located on the opening side of the body, covers substantially the entire surface of the tip of the body part inserted into the measurement hole, and applies a predetermined pressure to the tip. The reason is that a pressure means is provided.

(Effects of the Invention) That is, the blood pressure measuring device having the structure according to the present invention is provided with a tip pressurizing means, and the tip pressurizing means applies pressure to the distal end portion of the subject. As a result, blood is forcibly pumped out from the peripheral side of the subject through the veins.

Therefore, when performing blood pressure measurement while applying external pressure to the blood pressure measurement site using a compression means, in parallel with the blood pressure measurement, at a predetermined time interval, the tip portion that protrudes from the measurement hole is By applying a predetermined pressure with the tip pressurizing means, congestion at the distal end of the subject can be effectively released, and therefore, the external pressure on the subject due to the compression means is released. This makes it possible to perform continuous blood pressure measurements without any trouble, and the operation can be made extremely easy.

(Example) Hereinafter, in order to clarify the present invention more specifically, one example having a structure according to the present invention will be described in detail with reference to the drawings.

The figure shows an embodiment of a continuous blood pressure measuring device having a structure according to the present invention, in which the middle phalanx of a finger is used as the measurement site. In this figure, reference numeral 10 denotes a main body of a detection unit of a known blood pressure measuring device that performs non-invasive continuous measurement of intravascular pressure based on a volume compensation method, and has annular presser plates 12 and 12 at both end openings. A compression cuff 16 made of an elastic thin film of rubber, polyurethane, etc. is provided within a cylindrical chamber forming body 14 to which is fixedly attached.

This compression cuff 16 forms a ring-shaped sealed space between it and the inner wall surface of the chamber forming body 14, and the subject's finger 20 is inserted into the measurement hole 18 passing through the center of the ring-shaped space. By doing so,
The detection unit main body 10 is adapted to be attached to the middle phalanx of the finger. Further, a predetermined fluid or gas is sealed in the sealed space of the compression cuff 16, and the compression cuff 16 is connected to a pressurizer 22 such as a diaphragm actuator to operate the pressurizer 22. By changing the volume of the sealed space within the compression cuff 16, the external pressure applied to the finger 20 inserted into the measurement hole 18 is controlled to be increased or decreased.

Further, in the chamber forming body 14, a light source 24 made of a light emitting diode is arranged to face the side surface of the finger 20, while an inner circumference of the compression cuff 16 facing the light source 24 with the finger 20 in between is disposed. On the surface is a photoelectric detector 2 consisting of a phototransistor.
6 is provided, and these light sources 24 and photoelectric detectors 26 constitute a device for detecting changes in blood vessel volume using the light absorption characteristics of blood at the relevant part of the finger 20, as is known in the art.

The detection unit main body 1 having such a structure
As is well known, although not shown in the figure, the output signal from the photoelectric detector 26 is
The pressure applied to the outer surface of the middle segment of the finger 20 by the compression cuff 16 is introduced into a control system composed of a servo system, and the operation of the pressurizer 22 is controlled based on the output signal. is now being controlled in a controlled manner.

That is, such control systems typically
A system configuration in which an open-loop operation is performed to determine the intravascular volume (servo target value) when the blood vessel wall is in an unloaded state, and a closed-loop operation is performed to cancel the volume change caused by the intravascular pressure load by controlling the pressure of the compression cuff 16. First, the servo target value is determined using the volume pulse wave amplitude maximum phenomenon in open loop operation, and then the system is closed loop and the output signal from the photoelectric detector 26 is compared with the servo target value. By outputting a driving signal for the pressurizer 22 based on the difference signal and controlling the internal pressure of the pressurizing cuff 16,
Intravascular volume compensation is performed so that the intravascular volume of the measurement site is kept constant at the servo target value.

Therefore, the change in external pressure (internal pressure of the compression cuff 16) required to clamp the intravascular volume to the servo target value by such volume control always matches the change in the intravascular pressure, and therefore, the external pressure can be adjusted appropriately. The desired intravascular pressure (arterial blood pressure) can now be measured by measuring and recording it using suitable means.

On the other hand, the detection unit main body 10 having the structure as described above
In the subject's finger 20 inserted into the measurement hole 18 , a finger tip pressurizing body 28 is attached to the distal end portion protruding from the measurement hole 18 .

The finger tip pressurizing body 28 has a cylindrical bag-like shape made of an elastic material such as rubber, with respect to a bottomed cylindrical body 30 having an annular presser plate 29 fixed to its opening. The pressurizing cuff 32 has an end edge that is connected to the cylindrical body 30.
The pressure cuff 32 and the inner wall surface of the cylinder 30 form a sealed space. Further, this pressurizing cuff 32 is connected to the detection section main body 10.
When the distal end of the finger 20 of the subject's finger 20, which has been protruded from the measurement hole 18 of It is formed with an inner diameter.

A predetermined fluid or gas is sealed within this sealed space, and the space is connected via a valve means 36 to a pressurizer 38 capable of outputting a constant pressure. Such valve means 36
The sealed space formed by the pressurizing cuff 32,
It has a function of selectively switching between a state of communication with the pressurizer 38 and a state of being open to the atmosphere, and its operation is controlled by the control device 34. This control device 34 is configured to include a setting device that can arbitrarily set the time interval at which the valve means 36 is switched. Thus, the inside of the sealed space of the pressurizing cuff 32 is pressurized to a predetermined pressure value set in the pressurizer 38.

Although not shown, the control device 34
When the valve means 36 is controlled to be in communication with the pressurizer 38, a predetermined signal is output to the external pressure (internal pressure of the compression cuff 16) recording device, thereby causing the finger tip to The operating state of the partial pressure body 28 is recorded together with the measured blood pressure.

In such a device, when the inside of the compression cuff 32 is controlled to be in communication with the pressurizer 38 by the valve means 36, the measurement of the subject's finger 20 is performed by the finger tip pressurizing body 28. A predetermined pressure is applied to the distal phalanx protruding from the hole 18, thereby increasing the internal pressure of the venous blood vessels and forcing the blood present in the distal phalanx toward the proximal phalanx of the finger. It ends up being pushed out.

Therefore, when continuously measuring blood pressure by applying external pressure to the middle part of the finger 20 with the detection unit main body 10, in parallel with the blood pressure measurement,
By applying a predetermined pressure to the distal phalanx of the finger 20 at a predetermined time interval with the finger tip pressurizing body 28, the pressure on the distal phalanx generated by the external pressure from the detection unit main body 10 is reduced. Congestion can be effectively relieved, and therefore, by using the device in this example, it is possible to continuously measure blood pressure over a long period of time without causing pain to the subject. .

Note that the operation of the finger tip pressurizing body 28 is controlled intermittently, for example, at intervals of 1 minute and continuously for 30 seconds. The interval should be selected appropriately depending on the subject and his/her condition. Further, the pressure applied to the finger 20 by the finger tip pressurizing body 28 moves the blood congested in the distal phalanx to the proximal phalanx side via the middle phalanx where external pressure is applied by the detection unit main body 10. Any pressure value that can push through the blood vessels is fine, but
Preferably, the value is set to a value equal to or higher than the systolic blood pressure at the blood pressure measurement site.

In addition, the blood pressure measuring device according to this embodiment is extremely easy to operate since there is no need to release the external pressure applied to the fingers by the detection unit body 10 in order to release congestion. .
However, in such a device, the finger tip pressurizing body 28
It is difficult to accurately detect blood pressure when a predetermined pressure is applied to the distal phalanx, but in this device, the operating state of the fingertip pressurizer 28 is recorded at the same time as the measured blood pressure. Because of the structure, there will be no problem when measuring or confirming blood pressure.

Although one embodiment having a structure according to the present invention has been described in detail above, this is a literal illustration, and the present invention should not be construed as being limited only to this specific example.

For example, the finger tip pressurizing body 28 in the above embodiment
It is composed of a bottomed cylindrical body 30 with an annular presser plate 29 fixed to the opening and a bag-shaped pressurizing cuff 32, which prevents outward and lateral movement during pressurization. Although the expansion was restricted, it is also possible to make the entire body of an elastic material, and furthermore, the insertion opening for the fingers 20 of the cylinder body 30 is sealed, and fluid pressure or air pressure is applied directly to the relevant part. You can also do it like this.

In addition, in order to prevent the finger tip pressurizing body 28 from slipping off from the finger 20 when pressurizing the finger tip pressurizing body 28, the detecting unit main body 1
It may be fixed with respect to 0, and it is also possible to form the finger tip pressurizing body 28 integrally with the detection unit main body 10.

Further, in the embodiment described above, the operation of the finger tip pressurizing body 28 was controlled by the switching operation of the valve means 36 by the control device 34, but the operation control method is different from the above. Any device may be used as long as the operation of the finger tip pressurizing body 28 is controlled intermittently at predetermined time intervals. For example, the operation of the pressurizing device 38 may be directly controlled by the control device 34. be.

In addition, in the embodiment described above, the operating state of the finger tip pressurizing body 28 was configured to be recorded at the same time as the measured blood pressure. may be input to cancel recording under that operating state. However, such recording of the operating state of the finger tip pressurizing body 28 is not necessarily necessary.

Furthermore, in the blood pressure measuring device in the above embodiment, transmission photoplethysmography was adopted as a method for detecting changes in blood vessel volume, but the present invention employs reflection photoplethysmography, ultrasonic waves, Of course, it can be applied to blood pressure measuring devices that measure blood vessel volume changes using bioelectrical impedance, as well as blood pressure measuring devices that use volume compensation methods with other structures, and even the measurement site can be adjusted to the wrist. The present invention can also be effectively applied to blood pressure measuring devices that measure blood pressure at other sites such as the fingertips and the proximal phalanges of the fingers.

In addition, although not listed in detail, the present invention can be implemented in various modifications, modifications, improvements, etc. based on the knowledge of those skilled in the art, and such embodiments may be implemented in accordance with the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not depart from the spirit of the invention.

[Brief explanation of the drawing]

The figure is a partially cross-sectional explanatory diagram showing an embodiment of a blood pressure measuring device having a structure according to the present invention. 10: Detection unit main body, 16: Compression cuff, 18:
Measurement hole, 20: Finger, 22: Pressurizer, 28: Finger tip pressurizing body, 32: Pressure cuff, 34: Control device,
36: Valve means, 38: Pressurizer.

Claims (1)

[Scope of Claims] 1. It has a measurement hole into which a body part such as a finger is inserted, and a compression means for compressing the body part inserted into the measurement hole, and is provided with a pressure means for compressing the body part inserted into the measurement hole. The blood pressure measuring device is configured to extract a desired blood pressure signal by applying external pressure to the blood pressure measuring device, the blood pressure measuring device being located on one opening side of the measuring hole and measuring the part of the body inserted into the measuring hole. 1. A blood pressure measuring device comprising a tip pressurizing means that covers substantially the entire surface of the tip protruding from the hole and applies a predetermined pressure to the tip.