JPS58149732A - Non-observing type hemomanometer - 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 The present invention relates to a non-invasive blood pressure monitor, and more specifically, to a blood pressure monitor that can measure blood pressure without limiting the cuff to the upper arm.

Blood pressure measurement is generally divided into two types: a viewpoint method and a non-invasive method.

The viewpoint method is one in which blood pressure and its fluctuations are measured directly by cutting the blood vessel or inserting a needle into the blood vessel and leading it to a pressure gauge. Specifically, a force tail (hollow tube) or sensor filled with liquid is inserted into the measurement site, blood pressure and its fluctuations are guided to a pressure transducer placed outside the body, and the output signal of the transducer is amplified. , record and display.

However, blood pressure measurement using this method involves directly inserting a needle or the like into a blood vessel, which places a burden on the patient and does not allow easy measurement of blood pressure.

Therefore, except in special cases, a non-invasive method, that is, a method of measuring blood pressure indirectly from outside the body, is now widely used.

Currently, the most common indirect method is called the auscultation method, which is performed according to the following steps.

First, a cuff (compression band) is wrapped around the upper arm, and after increasing the internal pressure of the cuff with a pressure pump, the pressure is gradually reduced while
Place a stethoscope over the elbow artery and auscultate. When the internal cuff pressure matches the systolic blood pressure value, you will hear the Korotkoff sound that occurs in synchronization with the heartbeat (the blood flow passing through the cuff artery collides with stationary arterial blood on the distal side). The systolic blood pressure and diastolic blood pressure are measured by listening to the sound that vibrates the blood vessel wall and confirming that the Korotkoff sound disappears when the cuff internal pressure matches the diastolic blood pressure value.

By the way, blood pressure is the pressure inside a blood vessel relative to atmospheric pressure, so it varies depending on the location of the blood vessel, with the blood pressure being highest in areas near the heart and lowest in capillaries and veins. Generally, blood pressure is measured based on the blood vessels at the heart, so when blood pressure is measured by the auscultation method, the cuff is usually wrapped around the upper arm at the same height as the heart.

However, when a cuff is wrapped around the upper arm, there is a large amount of air to compress, which places a heavy burden on the patient.Therefore, it is not possible to repeatedly measure the cuff over and over again, and the position where the cuff is wrapped cannot be accurately determined. It is difficult to adjust the height of the heart to the height of the heart, so measurement errors are unavoidable.

Therefore, the present invention makes it possible to pull out the sensor part from inside the cuff to the outside and attach it to the same height as the heart, thereby connecting the inside of the cuff and the hollow tube leading to the sensor with blood. The cuff is filled with a fluid of the same specific gravity, and the cuff can be wrapped anywhere in the area without being limited to the upper arm, thereby eliminating the deficiencies of the conventional method.

Hereinafter, the blood pressure monitor according to the present invention will be explained in detail based on an illustrated embodiment.

The blood pressure monitor shown in the figure has a cuff wrapped around the finger.
This shows a case of measurement using a non-invasive method, which is different from the conventional auscultation method.

However, in the present invention, there is no problem in measuring with the conventional auscultation method.

Figure 1 is an explanatory diagram when blood pressure is measured using the sphygmomanometer of the present invention, in which the sensor (4) (including pressure cadence juicer, etc.) is attached to the heart region, and the cuff (1) is attached to the heart. Wrap it around your finger. Further, the output of the sensor is converted into an electrical signal and connected to a recording device (5)K, which will be explained in detail later.

The sensor (4) and the cuff (1) are connected through a flexible hollow tube (3). A hollow tube (6) connecting the pump (2) is also connected to the cuff.

These hollow tubes (3), (6) and the cuff are filled with a liquid having a specific gravity similar to blood, and the cuff is pressurized by a pump.

Now, when fluid is supplied to the cuff with a pump and pressurized, the pressure inside the cuff increases, and the internal pressure of the cuff increases sequentially as shown in Figure 2 (a). In addition, the cuff internal pressure waveform shown in is more accurately the cuff internal pulse waveform shown in Figure 2 (b), but
For simplicity, it is shown as a straight line as shown.

Next, when the intracuff pressure is gradually reduced, the intracuff pulse waveform increases sequentially as shown in Figure 2 (b), and then gradually decreases after reaching a certain peak value [the intracuff pressure at this time is the mean blood pressure (BP)]. do.

v Next, when we take the difference between these in-cuff pulse waveforms, we get the result shown in Figure 2 (c). The positive peak value in the figure is the systolic blood pressure (BP
), and a negative ax value corresponds to diastolic blood pressure (BP, ).

ln Figure 3 shows the circuit configuration of this example. In the diagram, the parts excluding the cuff, sensor, and pump are the recording device (
Corresponds to 5).

The signal detected by the pressure sensor (4) is divided into Do minutes (
Cuff internal pressure) and AC (pulsating flow); the former is DC
After passing through an amplifier (7) and a converter (8), it becomes one data source for the microcomputer (10). On the other hand, the latter becomes another data source for the microcomputer via an AC amplifier (9).

The microcomputer (10) recognizes whether the arterial wave is detected correctly, calculates the difference in waveform energy, recognizes the two peak points of the difference as the blood pressure value, and stores the pressure value at the peak point in the memory (11). It has a program to control it and other controls.

Note that the timer (12) is used to set the measurement interval.

Blood pressure can be measured by measuring the peak of the difference in arterial waves because the amount of blood changes due to changes in the internal pressure of the cuff, and because changes in the blood vessel wall inside the cuff affect the cuff rapidly. This is because it is possible to find out the points where the change occurs based on the difference.

The configuration of the present invention has been described in detail above, and the configuration provides the following unique effects.

That is, in the present invention, since the sensor part is drawn out from inside the cuff, it is attached to a site at the same height as the heart, and a hollow tube connecting the inside of the cuff and the sensor and the cuff is connected to the blood flow. Because the sensor is filled with fluid of the same specific gravity as the cuff, the sensor accurately indicates the blood pressure at the heart, no matter where on the body the cuff is placed.

Moreover, in the present invention, the cuff can be wrapped around any part of the human body, so if the cuff is wrapped around the finger, for example, where the capacity for pumping fluid is small, as in the embodiment, there is no burden on the patient. Therefore, repeated measurements of blood pressure are possible, and blood pressure can be easily monitored over a long period of time.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention. Figure 1 is an explanatory diagram of the state of use, Figure 2 is an explanatory diagram of a modeled blood pressure waveform observed by a recording device, and Figure 3 is an illustration of the configuration of the measurement circuit. Show the diagram. [Explanation of symbols of main parts] Cuff ・−−−−−−−−−−−−−−−−
−−−−−−−−−−−−−−−−−−−1−1 pump ・−m−−−−−−−−−−−−−−−−
−−−−−−−−−−−−−−−−2 hollow tube−−−−
−−−−−−−−−−−−−−−−−−−−−−−−−
−1−−−−−−3 sensor−−−−−−1−1−−
−−−−−−−−−−−−−−−−−−−−−−−−−
--4 Figure 1 (/

Claims (1)

[Claims] 1. A cuff (1) that is wrapped around the human body at an appropriate location, a pump (2) that supplies and pressurizes a fluid with a specific gravity similar to blood to the cuff, and a hollow tube (3) that communicates with the cuff. A non-invasive blood pressure monitor comprising at least a sensor (4) installed at an appropriate position in a hollow tube.