JPH0524325Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention uses an ultrasonic transducer and a pressure sensor to simultaneously measure and display the systolic blood pressure in the limb arteries and the pressure index value at the measurement site. The present invention relates to a limb artery diagnostic device.

[Prior Art] When occlusion or stenosis occurs in a limb artery, the blood flow to the distal artery is obstructed, and the supply of oxygen and nutrients to the area distributed by the artery becomes insufficient, resulting in severe pain, numbness, and other symptoms. Blood symptoms appear.

Although there are various methods such as angiography and isotope methods for diagnosis of arterial occlusion disease, follow-up observation, and determination after revascularization, non-invasive blood pressure measurement is suitable for daily diagnosis.

This makes it easy to measure each limb, allows the measured values to be directly applied to clinical practice, and is easy for doctors and patients to understand. Moreover, since the testing means are relatively simple, quantitative judgments can be made, and the diagnostic rate is also high.

Currently, blood pressure is usually measured in the lower limbs by placing a probe on the dorsalis pedis artery or the posterior tibial artery and using cuff pressure attached to the measurement site (lower limb, thigh, etc.). That is, the cuff pressure is once raised above the systolic pressure, the cuff pressure is lowered, and the cuff pressure when the Doppler sound upon resumption of blood flow can be heard for the first time is defined as the systolic pressure.

[Problem that the invention aims to solve] In the past, cuff belts (tourniquets)
Since the blood pressure of the extremities is measured using
When there are many measurement sites, it is necessary to repeat the re-wrapping and pressurization of the cuff band for each measurement site. Therefore, there is a drawback that measurement takes time.

Furthermore, the length and width of the cuff band vary depending on the measurement site, and there is a risk that fluctuations and errors in the measured blood pressure value may occur due to inappropriate use of the cuff.

Furthermore, in the past, since only the blood pressure value at the measurement site was measured, it was not possible to easily determine the presence of lesions such as stenosis or occlusion between the reference site (brachial artery) and the measurement site.

Therefore, this invention proposes a diagnostic device for limb arteries that can easily measure the systolic blood pressure value and also predict the discovery of lesions up to the measurement site.

[Means for solving the problem] In order to solve the above-mentioned problem, in this invention,
an ultrasonic probe having an ultrasonic transducer and a pressure sensor; a means for calculating a systolic blood pressure value based on the detection output of the pressure sensor; and a blood pressure value at a reference measurement site and a blood pressure value at the measurement site. The device is characterized by comprising means for calculating a pressure index value at the measurement site and a monitoring means, and displaying the pressure index value at the measurement site together with the systolic blood pressure value. .

[Operation] When the ultrasound probe 10 is applied to the skin surface and the skin surface is compressed by the ultrasound probe 10, the blood vessel 20 is compressed and blood flow is stopped.

The pressure is then reduced, and at some point blood begins to flow. When the blood begins to flow, the reflected wave of the ultrasonic signal (transmission signal) irradiated to the blood vessel 20 is obtained as a signal subjected to the Doppler effect according to the blood flow velocity.

The pressure applied to the blood vessel when blood begins to flow is detected by the pressure sensor 12, and a value obtained by converting the pressure value into mercury pressure (systolic blood pressure value) is displayed on the monitor 45. The pressure applied to the blood vessels when this blood flow sound begins is the systolic blood pressure value.

In addition, the ratio (pressure index value PI) between the systolic blood pressure value at the reference measurement site (brachial artery) and the systolic blood pressure value at the measurement sites on the extremities is calculated and displayed. This pressure index value PI makes it possible to predict stenosis and occlusive lesions between measurement sites.

[Example] Next, an example of the apparatus for diagnosing limb arteries according to this invention will be described in detail with reference to FIG. 1 and subsequent figures.

In this invention, an ultrasonic transducer (ultrasonic sensor)
The purpose is to measure the systolic blood pressure value and display the pressure index value PI using a pressure sensor.

The configuration of such an ultrasonic probe 10 will be explained first.

FIG. 4 shows an example of the ultrasonic probe 10. The ultrasonic probe 10 is a hollow columnar case 1 having a predetermined length and diameter, and is located at a position slightly shifted to the right from the center. A through hole 4 is provided to house the ultrasonic sensor 5 and pressure sensor 12. On the contrary, a lead-out hole 3 for taking out a signal cable line is bored on the left side.

The vicinity of the tip hole 2 of the through hole 4 is selected to have a tapered shape, and the ultrasonic sensor 5 is slidably inserted into the tip hole 2.

The ultrasonic sensor 5 has a bottomed cylindrical casing 6, and on its open end side there is a vibrator 7 for detecting the sound of blood flow flowing in the blood vessel, and in this example, a vibrator 7 for detecting the blood vessel wall. child 8 are arranged side by side. The transducer 7 for blood flow sound detection has a transducer 7a for transmitting waves and a transducer 7b for receiving waves as described later (see FIG. 1), but the transducer 8 for detecting blood vessel walls has It may be provided as necessary, and in that case, it will be configured to be used for both transmitting and receiving waves.

The reason why they are provided independently is that the former uses continuous waves, whereas the latter uses pulse waves for blood vessel wall detection.

Reference numeral 9 denotes a terminal plate, to which vibrators 7 and 8 are attached and fixed.

A pressure sensor 12 is provided on the upper end surface side of the ultrasonic sensor 5 to detect pressure applied to the ultrasonic sensor 5 itself. This pressure sensor 12 is a flat element, and its contact protrusion (sensing part) 12a is fixed to a mounting shaft 11 on which the ultrasonic sensor 12 is slidable so as to be in contact with the upper end surface of the pressure sensor 5. ing.

Therefore, the upper part of the through hole 4 has an inward flange 1.
3 is formed, and a cylindrical spring receiving portion 14 having an outward flange 14a that abuts against the inward flange 13 is fitted therein.

A mounting shaft 11 of the pressure sensor 12 is slidably inserted into the spring receiving portion 14 so as to pass through the spring receiving portion 14, and a lower end portion of the mounting shaft 11 serves as a mounting portion 15 of the pressure sensor 12. The mounting portion 15 is configured as a large diameter portion as shown in the figure.

A spring 18 is interposed between the large-diameter attachment portion 15 and the outward flange 14a to prevent overload.

In addition, the washer 16 that functions as a stopper
is screwed onto the upper end side of the mounting shaft 11 by a screw 17 to restrict the amount of downward movement of the mounting shaft 11 (elongation caused by the spring 18).

Now, when the ultrasonic probe 10 is configured in this way, the ultrasonic probe 10 is used with the tip of the ultrasonic sensor 5 in contact with the skin surface. Because the ultrasonic sensor 5 is configured to be slidable when the ultrasonic probe 10 is strongly applied to the skin surface,
Since the pressing force is transmitted to the pressure sensor 12, the detection output corresponding to the pressing force is transmitted to the pressure sensor 12.
obtained from.

When an overload condition occurs in which the pressing force becomes larger than the biasing force of the spring 18, the mounting shaft 11 slides upward against the biasing force of the spring. This prevents the pressure sensor 12 from being destroyed. When the overload condition is released, the spring 18
Due to this action, the mounting shaft 11 returns to its original position. The original position is regulated by a screw 17.

Now, when the ultrasound probe 10 is applied to the skin surface and pressure is applied to the skin surface with the ultrasound probe 10, the blood vessel 20 shown in FIG. 1 is compressed and the blood flow is stopped.
Waveform _a1 ) in figure.

When the pressure is reduced from this state, blood begins to flow at a certain point _t2 . When blood begins to flow, blood vessels 2
The reflected wave of the ultrasonic signal (transmission signal) irradiated to the ultrasonic wave 0 is obtained as a signal subjected to the Doppler effect according to the blood flow velocity. When a speaker is driven by the received signal a ₂ (Fig. 5) that has undergone this Doppler effect,
I can hear the sound of blood flowing.

The pressure applied to the blood vessel 20 when this blood flow sound begins corresponds to the systolic blood pressure value.

When the pressure is further reduced, the blood vessel 20 returns to its normal state and its waveform becomes a ₃ (FIG. 5). This waveform is a blood flow velocity waveform, and its detailed waveform is as shown in FIG.

FIG. 1 is a system diagram showing an example of a limb artery diagnostic apparatus using such an ultrasound probe 10. In the figure, the vibrator 8 is omitted for convenience of explanation.

The ultrasonic signal (continuous wave signal) of about 5 MHz output from the high frequency oscillator 31 is sent to the high frequency output circuit 32.
The signal is supplied to the wave transmitting vibrator 7a through the wave transmitting vibrator 7a, and the wave transmitting vibrator 7a is excited.

When the transmitting transducer 7a is excited by the ultrasonic signal, the ultrasonic wave is irradiated toward the blood vessel 20.

Since the frequency of the reflected ultrasound wave is modulated by the blood flowing through the blood vessel 20, a reflected wave subjected to the Doppler effect is obtained. After the reflected wave is received by the wave receiving oscillator 7b, it is supplied to the detection circuit 34 via the high frequency amplifier 33. A high frequency signal is supplied to the detection circuit 34 as a carrier.

The detected received signal a is passed through a band pass filter 35.
After the noise component is removed by the low frequency amplifier 3
The blood flow sound is supplied to the speaker 37 through the speaker 37 and emitted. 38 is a headphone terminal.

The received signal a and the carrier are further supplied to a frequency/voltage conversion circuit 40, where the frequency of the received signal a is converted into a voltage. The converted voltage corresponds to blood flow velocity. - After the V conversion output b is converted into a digital signal with a predetermined number of bits by the A/D converter 42,
The signal is supplied to the CPU 43 and subjected to various signal processing. The changeover switch 41 is a switch for switching between the calibration signal and the f/V conversion output b, and
50 is a generation circuit for this calibration signal.

Furthermore, the detection output detected by the pressure sensor 12 is taken into the CPU 43 via the amplifier 51. this
The PCU 43 converts the input pressure detection output into mercury pressure, and calculates the systolic blood pressure value.

The systolic blood pressure value processed by the CPU 43 is sent to the monitor 45 via the monitor interface 44.
is supplied to On this monitor 45, a human body model as shown in FIG. 2 is displayed, and a mark (○ mark in the figure) indicating a measurement site is displayed, and the above-mentioned systolic blood pressure value is displayed at the position of the measurement site.

The designation of the measurement site is input from the keyboard 55. This key input data is transmitted to the control circuit 56.
As a result, the designated measurement site can be easily recognized by causing the mark of the measurement site to blink or to be displayed in a different display color. Then, the systolic blood pressure value (for example, numerical value only) is displayed together with the signal "P:" at a position related to the mark of the measurement site.

The measurement site shown in FIG. 2 is an example.

The CPU 43 further calculates a pressure index value PI. The pressure index value PI is the ratio of the systolic blood pressure value at the reference measurement site and the current measurement site.

The reference measurement site is usually the brachial artery, so if the brachial artery's systolic blood pressure Po is 120 and the ulnar artery's systolic blood pressure P is 125,
Pressure index value at this ulnar artery
PI is PI=125/120=1.04.

This pressure index value PI is displayed together with the systolic blood pressure value P at the measurement site, in this example, the ulnar artery.

The pressure index value PI is effective in detecting lesions such as stenosis or occlusion up to the measurement site. If the pressure index value PI is PI>1.0...normal state 0.7<PI<1.0...almost normal state 0.3<PI<0.7...stenotic state PI<0.3...the lesion state is diagnosed as obstructed state.

Both the systolic blood pressure value P and the pressure index value PI are supplied to a printer 47 via a printer interface 46 so that they can be printed out. Printer 47 is controlled by remote control switch 57.

The systolic blood pressure value calculated by the CPU 43 is further converted into an analog signal by the D/A converter 48, and then output to the external output terminal 49 together with the output of the band pass filter 35. Further, this systolic blood pressure value etc. is further displayed by the liquid crystal display control circuit 58.
The blood pressure is supplied to a liquid crystal display 59 through which the systolic blood pressure value and the like are displayed.

[Effects of the invention] As described above, in this invention, the pressure index value can be measured and displayed along with the systolic blood pressure value using an ultrasonic sensor and a pressure sensor.

According to this method, it is possible to measure the systolic blood pressure value more easily than the conventional method of measuring blood pressure by wrapping a cuff band around the measurement site, since it is sufficient to simply apply the ultrasound probe to the measurement site such as the upper arm. has. When there are a large number of measurement sites, the work of attaching the cuff band is relatively troublesome, but this invention does not require such trouble at all.

In addition, since the length and width of the cuff band differ depending on the measurement site, there is a risk of fluctuations or errors in the measured blood pressure value due to the use of an inappropriate cuff band, but this invention completely eliminates this risk. do not have.

Furthermore, since a pressure index value is calculated, it is possible to easily determine the presence of lesions such as stenosis and occlusion between the reference site (brachial artery) and the measurement site.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of the main parts showing an example of the limb artery diagnostic device according to this invention, and Fig. 2 is an example of display of the human body model and measurement sites displayed on the monitor, as well as their systolic blood pressure values and pressure index values. 3 is a diagram of a blood flow velocity waveform, FIG. 4 is a longitudinal sectional view showing an example of an ultrasound probe, and FIG. 5 is an explanatory diagram of the operation of the ultrasound probe. 1... Case, 5... Ultrasonic sensor, 7, 8...
... Vibrator, 10 ... Ultrasonic probe, 12 ... Pressure sensor, 20 ... Blood vessel, 43 ... CPU, 45 ...
...Monitor, 47...Printer, 55...Keyboard.

Claims (1)

[Scope of Claim for Utility Model Registration] An ultrasonic probe having an ultrasonic transducer and a pressure sensor, means for calculating a systolic blood pressure value based on the detection output of the pressure sensor, a blood pressure value at a reference measurement site, The device has means for calculating a pressure index value at the measurement site from the blood pressure value at the measurement site, and a monitoring means, and displays the pressure index value at the measurement site together with the systolic blood pressure value. A limb artery diagnostic device characterized by: