JPS60176634A - Artery hardening degree 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 Field of the Invention The present invention relates to an arteriosclerosis measurement device that non-invasively measures arteriosclerosis.

<Prior art> Conventionally, a known method for determining the degree of arteriosclerosis non-observatively by JMI is to measure the pulse wave propagation velocity and calculate the body fr1 elastic modulus of the blood vessel wall from this. . In this method, for example, as shown in Japanese Unexamined Patent Publication No. 11'7279 and Japanese Patent Application Laid-Open No. 52-108684, pulse waves are measured at two points on the subject's body. The pulse wave propagation velocity is calculated from the propagation time during that time, and the bulk elastic modulus of the blood vessel wall is calculated. Therefore, the average value of the bulk elastic modulus of the blood vessel wall between those two points is calculated. However, it is impossible to measure the bulk modulus of the local vessel wall during that time.

For example, as shown in Japanese Patent Application Laid-Open No. 54-2'21086, a simulated electrical circuit that approximates the impedance characteristics of the carotid artery system by giving blood vessel diameter, carotid artery pressure wave, absolute flow velocity, etc. Taking into account the model's vascular resistance R1, the vascular resistance value I-, and the cerebrovascular welfare C, we determined the input impedance characteristics of the blood vessels from these constants to elucidate the vascular physical properties of the carotid artery, and from these carotid artery vascular characteristics, we calculated the cerebral circulation characteristics (cerebral circulation characteristics). There is no known method for determining blood vessel characteristics. However, this method does not actually measure the elasticity of blood vessels, but is based solely on simulation, and has the drawback that it cannot necessarily accurately determine the degree of stiffness of blood vessel walls.

In addition, the above-mentioned Japanese Patent Application Laid-open No. 571-21 (100) discloses an ultraviolet light transmitter that transmits M'rf waves to the arterial wall and a receiver that receives reflected waves from the arterial wall. Whether using a sonic probe or not, this ultrasonic probe 7
The use of the 111L vascular resistance R1 of a simulated electric circuit model that approximates the input impedance characteristics of the carotid artery system and the vascular inertia value, and the blood flow velocity as one data for calculating the cerebrovascular capacity C. , only 111 [
It only measures flow velocity. Utilization of such an ultrasonic probe and use of a transmitter that transmits ultrasonic waves at j = J to the arterial wall and a receiver that receives reflected waves from the arterial wall in the arteriosclerosis measuring device of the present invention The difference in purpose between and will become obvious in the following notation j′+.

<Objective of the Invention 1> The present invention was developed under these circumstances, and its purpose is to non-invasively change the bulk modulus (hardening degree) of the local 1 (11 tube). The purpose of the present invention is to provide an arteriosclerosis measuring device that can accurately measure the degree of arteriosclerosis.

<Structure of the Invention> In order to achieve such an object, the present invention includes a transmitter that transmits ultrasonic waves along the arterial wall, a receiver that receives reflected waves from the arterial wall, An extraction device is provided that extracts only the Doppler shift included in the reflected wave and outputs a voltage signal corresponding to the extracted Doppler shift.

In the arteriosclerosis measurement device configured in this way, the reflected wave from the arterial wall is divided into the waves transmitted from the wave transmitter to the arterial wall.
When the arterial wall expands in the radial direction due to the passage of a pulse wave, the frequency increases, and when it contracts, the frequency decreases. In other words, the reflected wave reflects the radial movement (pulsation) of the artery wall.
It is affected by the Doppler effect. The pulsation velocity of the arterial wall varies depending on the degree of stiffness of the artery wall, so by extracting only the Doppler shift that matches this reflected wave and calculating the pulsation velocity of the artery wall, the degree of stiffness of the artery wall can be determined. It can be measured.

<Example> Hereinafter, the present invention will be explained in detail based on the illustrated example.

FIG. 1 is a front circuit diagram of an arteriosclerosis measuring device according to an embodiment of the present invention. This arteriosclerosis degree 81 measuring device includes an oscillator 1 that outputs a frequency signal having a predetermined frequency (for example, 11', 3 M I-1z);
a filter circuit 2 that removes noise from the output of and extracts the required frequency multiplied by 3゛, an amplifier circuit 3 that amplifies the frequency signal extracted by the filter circuit 2, and converts the amplified frequency signal into an ultrasonic wave, Transmitter 1 is installed serially to transmit ultrasonic waves to the artery wall. In addition, the amplifier circuit 3
and the transmitter/1 with an impedance masochinc of 9
A matching circuit 5 for ij is inserted. On the other hand, this arteriosclerosis measurement device includes a receiver 6 that receives the anti-η wave from the artery wall and outputs a reflection frequency corresponding to the frequency of the anti-A j wave, and (From No. 8, constant frequency 'A' centered on the oscillation frequency of oscillator 1)
f'Jb.

(e.g. 3MHz±, '> fJ 01h) of 4.1
A bandpass filter circuit 7 for extracting the signal and an amplifier circuit 8 for amplifying the output signal of the bandpass filter circuit 7 to a required level are serially provided. l'l'l jl
, J.Z.wavelength filter (5) and the bandpass filter 7, another matching circuit 9 is inserted in order to obtain an impedance Manning.

Further, there is a suppressor 10 that adjusts the level (amplitude adjustment) of the output of the oscillator 1 in accordance with the output (11j) level of the amplifier circuit 8.
A mixer]1 which inputs and mixes the output of the sweat mixer 10 and the output of the amplifier circuit 8, and extracts only the Doppler shift 1·min contained in the reflected wave from the output of the sweat mixer J1. , an extraction device f4]2 that outputs a voltage signal corresponding to the extracted Doppler shift component. Furthermore, the second arteriosclerosis degree measuring device further includes the arterial wall motion velocity (1) calculated from the output of the extraction circuit 12 according to a predetermined calculation formula, and the arterial wall motion velocity (V) calculated from this motion velocity V according to a predetermined calculation formula. an arithmetic circuit 13 that calculates the bulk modulus of elasticity, etc.;
A display device 111 is provided to display the calculation results.

The ultrasonic waves transmitted from the transmitter 1 to the arterial wall are tilted by θ with respect to the perpendicular ρ to the area to be examined on the artery wall 15, as shown in FIG. The axis of the receiver 6, which receives the reflected wave from the artery wall 15, is tilted to the opposite side by θ.

If the arteriosclerosis lit storage device configured in this way: the waveform shown schematically in FIG. ! ) 1 Due to this radial movement (pulsation), the Doppler effect occurs, and the IID is emitted in the radial direction of the artery wall 15 → - At the end, the frequency increases as shown in part (a) of Figure 4. increases, and as the frequency increases, the frequency decreases as shown in part (1) of Fig. 4]. , the extraction device 12 extracts only the change in frequency, that is, the Doppler shift Δr included in the +ii+ reflected waves.
Then, the pulsation velocity V, the bulk modulus of the artery I, etc. are extracted using the calculation circuit 1;). The calculation formula for the arterial wall motion velocity V is as follows: (C is the sound velocity in living wood, approximately 1.5 t:l (l m/
5ec).

Various calculation results of the calculation circuit 13 are displayed on the display device 1...
1, displayed simultaneously or sequentially in digital display, analog display, or a combination of these display methods.

<Effects> As explained above, the present invention provides a non-invasive method by applying ultrasonic waves to one point on the artery wall and obtaining a voltage signal of 1 minute of Doppler shift, which is clipped to the motion velocity of the artery wall. The velocity of movement of the arterial wall can be measured both locally and locally. Soshi'C1
By further performing appropriate calculations from this arterial wall motion measure, the bulk modulus can be directly calculated and measured. Moreover, the measurement is performed accurately by directly measuring the movement of the measurement site.

4. Brief explanation of the drawings Figure 1 is a professional circuit diagram of an arteriosclerosis measuring device according to an embodiment of the present invention, and Figure 2 shows the state of use of its transmitter and delivery device. FIG. 3 is a waveform diagram schematically showing transmission waves, and FIG. 11 is a waveform diagram schematically showing foul waves.

, G... Transmitter, 6... Receiver, 12... Extraction device.

Applicant: Daikin Industries, Ltd. Agent: Patent Attorney Oka 1) Hide Kazu

Claims (1)

[Claims] (1) A transmitter ↓ that transmits ultrasonic waves to the artery wall 15 through tJ, a receiver 6 that receives the reflected waves from the artery wall 15, and a Doppler shift included in the reflected waves. extract,
This is an arteriosclerosis degree measuring device comprising an extraction device 12 that outputs a voltage signal that cuts the extracted Doplash within 1 minute.