JPH04109938A - Ultrasonic wave doppler diagnostic device - Google Patents

Abstract

PURPOSE:To measure a motion speed and a motion direction at any part correctly by providing a means to compute the motion speed and the motion direction based on the motion speeds of a motion body in two directions and scan angles. CONSTITUTION:In case transmission and receiving are performed for two different points P1, P2 in an ultrasonic wave transmitting/receiving surface 1' of an array type ultrasonic wave probe consisting of a plurality of ultrasonic wave vibrators disposed linearly, Doppler signals are obtained for detected motion speeds 2v1, 2v2 at ultrasonic wave scan lines l1, l2, so v1, v2 are determined base on the speeds 2v1, 2v2, and these v1, v2, and scan angles theta1, theta2 are substituted to determine a constant value and motion direction for a speed (v) of a motion body M, and for transmitting/receiving timings for the ultrasonic wave lines l1 and l2, l1 and l2 can be transmitted/received simultaneously, or with a time difference, for pairs of T1, R1 and T2, R2. As a result, the speed of the motion body for each direction can be detected, and the motion speed and motion direction of the motion body can be detected correctly by using these and the scan angles which are computation processed at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention emits an ultrasonic beam into a subject and detects the ultrasonic waves reflected from interfaces with different acoustic impedances between tissues within the subject. The present invention relates to an ultrasonic Doppler diagnostic apparatus that receives signals, detects the motion state of a moving body within a subject using the Doppler method, and displays the signals detected using the Doppler method superimposed on a tomographic image of the subject.

More specifically, in an ultrasound Doppler diagnostic device that transmits and receives ultrasound beams by phase-driving an array-type ultrasound probe in which multiple ultrasound transducers are arranged in a straight line, reflections from two directions are used. The present invention relates to an ultrasonic Doppler diagnostic device capable of receiving ultrasonic waves and detecting the speed and direction of movement of a moving body using the Doppler method.

(Prior Art) Conventionally, this type of ultrasonic Doppler diagnostic apparatus scans in the same direction while transmitting an ultrasonic beam and receiving reflected ultrasonic waves from an interface within a subject's body. Therefore, since the Doppler signal obtained by receiving only the ultrasound waves reflected from the interface in the subject's body in the transmission direction is detected, the motion state of the moving body inside the subject detected by the ultrasound Doppler method is There was a major drawback in principle that it was limited to the transmission direction of the acoustic beam, and the actual state of movement could not be diagnosed.

This point will be explained more specifically with reference to FIGS. 9 and 10.

In Fig. 9, 1 indicates an ultrasound probe, and ultrasound waves are transmitted and received along the directions of scanning lines Q, Q, Ω, . . . , and these scanning lines Q create an ultrasound image 2. is configured. Further, 3 is a blood vessel, for example, and if there is a moving body such as blood with a velocity V at a moving part p in the blood vessel 3, the motion velocity vf that can be detected by the ultrasonic Doppler method
f, , vQ, , vQ, are determined by the angle between the motion velocity V of the moving part p and the ultrasound scanning line α. This relationship is shown more specifically in Figure 0.

That is, in FIG. 1O, the ultrasonic scanning line α1°α, .
Let the angle between Q and the motion velocity V be θA, ,eQ, respectively.
,,θQ, then the motion velocities vQ,, vn,, vQ, which can be detected by the Doppler method, are the velocity vectors v cosθQ,,vcose in the directions of ultrasound scanning lines Q,,Q,,Q, of the motion velocity V, respectively. 3. vcosea,
Therefore, ■α corresponding to the scanning line Q becomes zero.

(Problems to be Solved by the Invention) As described in item 2, in the conventional method, the speed and direction of the moving body cannot be detected at all depending on the scanning direction, as in vQ above, and there are cases where quantitative performance is lacking. For this reason, in conventional ultrasound Doppler diagnostic equipment, the moving part is determined from the ultrasound image based on the experience and intuition of the image reader, and the speed of motion of the moving body is estimated by estimating the angle with the ultrasound scanning line. A calculation method is used. Therefore, there has been a problem in that the detection accuracy of movement speed and movement direction is low.

The present invention has been made to solve the above problems,
The purpose is to provide an ultrasonic Doppler diagnostic device that can accurately measure the speed and direction of movement of any part regardless of the scanning direction.

(Means for Solving Problem a) In order to achieve the above object, the present invention phase-drives an array type ultrasound probe in which a plurality of ultrasound transducers are arranged in a straight line to generate an ultrasound beam. In an ultrasonic Doppler diagnostic device capable of transmitting and receiving, means for receiving reflected waves of ultrasound transmitted toward a moving body within a subject along two directions with different scanning angles; The method includes means for detecting the speed of movement of the moving object using a picture-acoustic Doppler method, and means for calculating the speed of movement and the direction of movement of the moving object based on the speed of movement and the scanning angle of the moving object along the two directions. It is something.

Here, as a mode of receiving the reflected ultrasound from the direction of the moving body along two directions with different scanning angles, for example, a case where the ultrasound is transmitted and received from two different points on the ultrasound transmitting/receiving surface of the ultrasound probe. Or, when transmitting and receiving from one point and only receiving at another point, or when the speed of the moving body does not change between two scanning lines or when the scanning angle is relatively small, A case may be considered in which data is transmitted and received in two directions from a point.

(Function) FIG. 1 is a diagram showing the relationship between ultrasonic scanning lines and the speed of a moving body for detailed explanation of the present invention.

In the figure, ultrasonic waves are emitted from the ultrasonic transmitting/receiving surface 1' of an array type ultrasonic probe in which a plurality of ultrasonic transducers are arranged in a straight line, and reflected ultrasonic waves from a moving body inside the subject are emitted. Ultrasonic scanning lines α1 . For Q, the detected velocity signal obtained by the Doppler method is vl.

■, then line segments m, , m orthogonal to Qll α,
.

The line segment (vector) ■ between the intersection with the origin M and the origin M indicates the speed and direction of the moving body.

Here, X and Y are orthogonal reference axes for determining the speed and direction of the moving body, and the origin M is the origin of the orthogonal reference axes X and Y, and at the same time, It shows a moving body as an existing target. Note that the reference axis X is perpendicular to the ultrasonic transmitting/receiving surface 1'. Furthermore, the scanning angle θ3 of the ultrasonic scanning IIAΩ5°Q3. e, is based on the reference axis X, with the hour hand direction being negative and the counterclockwise direction being positive, and the unit vector u of the ultrasound scanning line Q
i2. ．． For uα, the direction of the arrow in the figure is the positive direction.

Under these assumptions, the ultrasound scanning line α,.

The unit vectors u Q,, u Q, of Q, are the unit vectors of the orthogonal reference axes X and Y, respectively, by 1. When J is expanded for each le, the following equation is obtained.

Furthermore, rearranging equation (4) results in the following equation.

Determining m and m from equation (5), we get this (
1) Expressing the formula as a general formula, u Q= 1cose+js
inθ.

Also, the line segment m l perpendicular to the ultrasonic scanning lines Q, , Q,
1m, unit vector u4. um, becomes, and if this formula (2) is expressed as a general formula, LIm=is
inθ−jcose.

Therefore, the intersection of line segments m, , m, is given by the following equation.

v uQ + m um=v, uL+m, us, -(
3) Substitute this equation (3) for each unit pect v of the orthogonal reference axes X and Y.
=((v,'+v,'+m,'+m,'')/])'.

Therefore, the quantitative value of the motion velocity ■ of the moving body M within the subject is v, , v, , θ1. If e is clear, it can be found by the following equation.

v==[((v,'+v,')-2v,v,cos(θ
,-e,))/sin'(e,-e,)do・6...(
7) Next, if we calculate the velocity components of the motion speed ■ for each of the orthogonal reference axes X and Y based on equation (4), vx = (v, cos θ,
+v, cos θ, )/2+(sine, (v, -v, c
os (e, -〇, )) + 5ine, (v, cos (e,
−θ, ) −v, )]/2/5in(θ, −
e, )...(8) vv=(v sine + v, sine,)/2+ [c
osθ1(VI-v, cos(e,-θI))+CO3
θ+ (v, cos(e, −〇, ) −v, )]
/2/5in(θ1-θ,)...(9) From this, the direction of movement becomes clear.

As mentioned above, two ultrasonic scanning lines Q with different scanning angles
By receiving the reflected ultrasound along ,,Q,,
The quantitative value and direction of the movement speed are determined, and the measurement principle is (7
), (8), and (9), and by substituting the received signal into these principle equations, the speed and direction of motion of the moving body M can be accurately determined by high-speed calculation.

(Example) The present invention will be described in detail below. In each of the embodiments, as described above, 1' is the ultrasonic wave transmitting/receiving surface, M is a moving body existing at a detection site within the subject, and this moving body M is moving at a certain speed V.

Also, T, T,, T, represents the transmission scan, and R, R,, R.

indicate the received scans, respectively.

First, FIG. 2 shows a first embodiment of the present invention. In this embodiment, two different points P, , P on the ultrasound transmitting/receiving surface 1'
, when transmitting and receiving from . As a result, the ultrasonic scanning lines Q,,Q.

Since a Doppler signal corresponding to the detected motion velocity 2 v,, 2 v, is obtained at the velocity 2 v,, 2
Find vl l VI from v, and these V l l
” m and scanning angle θ5.e3 as described in (7) to (9) above.
By substituting into the equation, the quantitative value of the velocity V of the moving body M and the direction of movement can be obtained. Here, the ultrasonic scanning line Q,
The transmission and reception timing of Q, is T,,R, and T,,R.
, 21 and Q3 may be transmitted and received at the same time, or at different times.

Next, FIG. 3 shows a second embodiment of the present invention. In this embodiment, transmission and reception are performed from one point P on the ultrasonic transmission/reception surface 1', and only reception is performed at other points P. As a result, the ultrasonic scanning line Ω1. At Ql, Doppler signals corresponding to velocities 2v, , v, 10V are obtained, and 0. Find V from the velocity 2v, and also,
Subtract the above v1 from the velocity v, +■ at Qyo to find ■, and substitute it into the above equations (7) to (9) together with the scanning angle θ1°θ to obtain the quantitative value of the speed ■ and the direction of movement. demand. In addition,
The timing of transmitting and receiving the ultrasonic scanning lines Q, Q, is as follows.
It is necessary to perform Q, ,Q at the same time in the bare state of T,,R,and R1.

FIG. 4 shows a third embodiment of the present invention, in which transmission and reception are performed from one point P on the ultrasonic transmitting and receiving surface 1'.
This is the case where only reception is performed at the other two points P, , P,. That is, Doppler signals corresponding to the velocities VT+v+, V+Vh in the ultrasonic scanning line Q,, Q, from the point P1°P, are obtained, and the ultrasonic scanning line Ω from the point P, A Doppler signal corresponding to velocity V7 is obtained at . Subtract this VT from the speed v clove v at 2 to get V3, and V7 to the speed v at P
7+v, subtracted from v.

, respectively, and vI I VI and scanning angle θ1 . in the same manner as above. By substituting θ into equations (7) to (9), the quantitative value of the velocity V and the direction of movement are determined. In this embodiment, it is necessary to simultaneously receive the ultrasonic scanning lines M, , and R.

FIG. 5 shows a fourth embodiment of the invention.

In this embodiment, one point P13 on the ultrasonic transmitting/receiving surface 1'
From scanning angle θ1. Transmission and reception are performed in two directions at ultrasonic scanning lines ff, , R, and when the motion speed of the moving body M does not change between the ultrasonic scanning lines ff, , R, or when the scanning angles e, , e,
This is effective when is small. According to this embodiment, Doppler signals corresponding to velocities 2v, 2v in the ultrasonic scanning lines Q, , Q, are obtained, and from these Doppler signals are obtained as follows:
V, is determined, and along with the scanning angle e I Jθ, (7) ~
The quantitative value of velocity V and the direction of movement are determined using equation (9).

The timing of transmitting and receiving the ultrasonic scanning lines Q,, Q, is T.
, , R, , T, , Ql and Q at the same time for the pair of R,
Or you can shift the time.

Next, FIG. 6 shows a fifth embodiment of the present invention.

In this embodiment, one point P1.
Transmission and reception are performed at a scanning angle θ1 from .

Only reception is performed in a different direction at a scanning angle e1. In this embodiment, like the fourth embodiment, the ultrasonic scanning line Q
This is effective when the motion speed of the moving body M does not change between , , Q, or when the scanning angle e, , e is small. According to this embodiment, a Doppler signal corresponding to the velocity 2v, v, +v in the ultrasonic scanning line Q, Q is obtained, so vl is determined from 2■, and this V can be found by subtracting from . As a result, the scanning angle θ3. The quantitative value of the speed (■) and the direction of movement are determined using equations (7) to (9) along with θ8.

FIG. 7 shows a sixth embodiment of the invention.

In this embodiment, one point P1.
Transmission and reception are performed in one direction from the scanning angle θ1. It only performs reception from the other two directions. This example also applies to the fourth example. As in the fifth embodiment, there are cases where the moving speed of the moving body M does not change between the ultrasonic scanning lines Q, , Q, and when the scanning angle e
This is effective when it is necessary to reduce l lθ1. According to this embodiment, the ultrasound scanning lines Q l + 2.
A Doppler signal corresponding to the velocity v7+v,, va+V, is obtained, 2v obtained from the ultrasonic scanning line 0 by transmission and reception is used to obtain ■7, and this V7 is subtracted from v7+v1 regarding Ql to obtain V, ■ Also regarding Q6. +V.

Subtract from to find v3. Thereafter, as above, (7) ~
The quantitative value of velocity V and the direction of movement are determined using equation (9).

Next, the configuration of an ultrasonic Doppler diagnostic apparatus to which each of the above embodiments is applied will be explained with reference to FIG. 8.

This diagnostic device includes an array-type ultrasound probe in which a plurality of ultrasound transducers are arranged in a straight line, and is configured to be able to transmit and receive ultrasound beams by driving the probe in phase.

In the figure, l is an array type ultrasonic probe, 2°300
, 400 is a matrix switch for transmission or reception, 5
, 600 is a scanning line control unit that controls the scanning angle and position of the ultrasonic scanning line, 7 is a transmitting circuit, 8,801°, 802 is a receiving circuit, 9,901 is a delay circuit, and 10.101 is a delay amount control. 11.111.112 is an aperture control section, 12.121.122 is an addition section, 13 is an amplification section,
14, 141.142 is an amplifier with TGC (time gain control) that corrects the attenuation of ultrasonic waves in the depth direction, 1
5, 151 is a mixer for lowering the receiving frequency of ultrasonic waves to the audio domain frequency, 16.161 is an LPF (
low pass filter), 17.171 is amplifier, 18°1
81 is an A/D converter, 19 is a speed calculator, 201 is a high-speed calculator that performs calculations such as the above-mentioned equations (7) to (9), and 2
0 is DBPF (dynamic band pass filter), 2
1 is a detection section, 22.221 is a TGC control section, 222 is s
in.

23 is a DSC (digital scan converter), and 24 is a TV monitor. It should be noted that among the above-mentioned components, those with three-digit numbers are unique to the present invention, and other components are also included in conventional ultrasound Doppler diagnostic devices.

Next, to briefly describe the operation of the components related to the present invention, the scanning line control section 600 controls the angle and position of transmission and reception in two directions, the receiving circuits 801 and 802, the delay circuit 901, and the aperture control section. The two received ultrasonic signals that have passed through 111 and 112 each become one time-series signal, and the frequency is lowered to the frequency of the audio domain after passing through amplifier units 141 and 142 with TGC and mixer +51. The signals corresponding to these two received signals are
L P F +61 for anti-aliasing. Amplifier+
71 and A/D converter +81 into a digital signal, and the speed calculator 19 converts the above ■l l vI
l vT is calculated and these signals are sent to the high-speed calculation unit 201.
is input.

On the other hand, the scanning angle θ outputted from the DSC 23.

e is also input to the high-speed arithmetic unit 201, and this high-speed arithmetic unit 2
By calculating equations (7), (8), and (9) in 01, the velocity V of the moving body M and the orthogonal reference axis X are determined.

The direction of movement can be accurately determined from the components along Y (VX, VV).

Note that, for example, an electronic linear probe or the like can be used as the ultrasonic probe used in the present invention.

(Effects of the Invention) As described above, according to the present invention, by receiving ultrasonic waves reflected from an interface within a subject along two directions with different scanning angles, The speed can be detected, and by performing high-speed arithmetic processing using these and the scanning angle, the speed and direction of movement of the moving body can be accurately detected. In particular, it is possible to eliminate the conventional disadvantage that speed cannot be quantified depending on the scanning direction.

[Brief explanation of the drawing]

Fig. 1 is a detailed explanatory diagram of the present invention, Figs. 2 to 7 are explanatory diagrams of the first to sixth embodiments of the present invention, and Fig. 8 shows a specific configuration of an ultrasonic Doppler diagnostic device. Block Diagram,
FIGS. 9 and 10 are explanatory diagrams of the conventional Doppler diagnosis method. 1... Ultrasonic probe 1'... Ultrasonic transmitting and receiving surface +
01...Delay amount control section Ill, +12...Aperture control section 121.12
2... Adding section 141, 142... Amplifying section with TGC +51...
Mixer 161...L P F +71...
・Amplifier +81...A/D converter 201...High speed calculation section 221=・TGC control section 222-・-5in,
Cos generator 300, 400...Matrix switch 600...Scanning line control section 801, 802...Receiving circuit 901...Delay circuit 111 Fig. zutanzu zuzu zu

Claims (1)

[Scope of Claim] An ultrasound Doppler diagnostic device capable of transmitting and receiving ultrasound beams by phase-driving an array-type ultrasound probe in which a plurality of ultrasound transducers are arranged in a straight line, comprising: means for receiving reflected waves of ultrasonic waves transmitted towards a moving object along two directions with different scanning angles; and means for detecting the motion speed of the moving object along the two directions using an ultrasonic Doppler method. An ultrasonic Doppler diagnostic apparatus comprising: means for calculating the speed and direction of movement of the moving body based on the speed of movement and scanning angle of the moving body along the two directions.