JPS62207441A - Ultrasonic diagnostic 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] [Object of the Invention] (Industrial Field of Application) The present invention relates to an ultrasonic diagnostic device that diagnoses tissue within a subject using ultrasound, and particularly relates to an ultrasonic diagnostic device that diagnoses tissue within a subject using ultrasound. The present invention relates to an ultrasonic diagnostic apparatus equipped with a sound velocity measurement and display function for characterizing tissues and providing diagnosis.

(Prior Art) The ultrasonic propagation velocity in a subject is influenced to a large extent by the composition present in the ultrasonic propagation path in the subject.

In other words, this means that it is possible to detect lesions such as tumors in organs, liver cirrhosis, etc. in a living body based on the ultrasonic propagation velocity. It is clinically important to measure #
There is JFa.

Therefore, attempts have been made to utilize this fact to obtain information on the ultrasonic propagation velocity in the living body and use this information to inspect the composition at a target position.

Conventionally, as a practical ultrasonic measurement method for such examinations, a method as shown in FIG. 7 using an electronic scanning type ultrasonic diagnostic apparatus has been proposed.

That is, in the figure, 1 is a probe for ultrasonic linear electronic scanning, and using this probe 1, ultrasonic pulses are emitted from -mA of an ultrasound receiving surface 2 in contact with a body surface (not shown) into the body in the θ direction. fire.

As is well known, electronic scanning type ultrasound AM uses a probe consisting of an ultrasound transducer array in which a plurality of ultrasound transducers (hereinafter simply referred to as perturbators) are arranged in parallel. A drive pulse is applied to each of the group of adjacent transducers with a predetermined delay time determined according to the direction of the transmitted ultrasound beam and the position of the transducer in the beam. The ultrasonic waves from each excited transducer propagate radially and interfere with each other, canceling each other in a certain B range and strengthening each other in a certain W4 region, resulting in This is a method of obtaining an ultrasonic beam.Generally, the reception is performed by the group of transducers used for transmitting the waves, and the detection signal of the group of transducers is delayed by the delay time at the time of transmitting the waves. After aligning the axes, they are combined to form a received signal.Then, by shifting the above group of @ moving elements one pitch at a time, the position of the generated ultrasonic beam shifts, so the excited camera element is shifted. By electrically selecting and controlling the excitation timing, linear scans can be performed, and sector scans can be performed at desired positions.

In this way, if the beam-shaped ultrasonic pulse generated in the θ direction is set at a position in the liver tissue, it will travel straight along the transmission path 4 in the liver tissue and go straight to the point P.
reflect. Here, out of this reflected wave (echo),
The echo that arrives at the probe 1 following the receiving path 5 is received not by the transducer group used for transmission, but by the transducer group at the incident position of the echo that has arrived (the transducer group at the right end B of the probe 1). let

Since the distance y between A and B is known, if the propagation time t of the ultrasound propagating along the path 4.5 is measured, the sound speed C in the liver tissue is C-y/(t-s inθ)- It can be obtained from (1).

This principle is used to measure the speed of sound. Since the speed of sound is unknown, θ is strictly unknown, and since there is no reflection point P in the living body, various methods are required to calculate the speed of sound from equation (1) above. It will also require some ingenuity. Therefore, an apparatus using this method has a configuration as shown in FIG.

In the figure, reference numeral 1 denotes an ultrasonic probe, and the probe 1 is constructed by linearly arranging 128 transducers T1 to T128 for transmitting and receiving ultrasonic waves. Transducer T
1. ~T128 The parallel arrangement corresponds to the ultrasonic wave transmitting/receiving surface 2 of the probe 1 in FIG.

12 is a lead wire; 13 is a multiplexer which is a circuit selection switch; 15 is a transmission delay circuit for obtaining the amount of delay to be given to each of a group of vibrators to be excited;
4 is a pulser that generates pulses for ultrasonic excitation drive, 16
17 is a receiving delay circuit for obtaining an echo delay m@ necessary for aligning the time axis etc. according to the receiving direction and element position for each of a group of transducers used for reception, and 17 is a receiving delay circuit for obtaining uniformity and character information. 18 is a calculation circuit, 19 is a transducer TI obtained through the reception delay circuit 16,
- A receiving circuit that synthesizes the received echo signals from T128, amplifies and transversely waves the signals, performs logarithmic conversion, corrects the signal level according to depth, and outputs the resultant signal as a received signal; 20 converts the received signal into a digital signal; An A/D converter for conversion, 21 is an oscillator for generating a clock signal for sequentially updating addresses in a memory in order to sample and store a rate pulse signal for driving a pulser and an echo from a target subject part, 22 23 is a memory for storing received signals, and 23 adds the stored data value at the same address of the memory 22 and new input data every time an ultrasonic pulse is generated, averages it, and stores the added average value at the corresponding address. A processing circuit 24 examines data indicating a peak value using the sample values of the received waveforms that have been subjected to the averaging process and is stored in the memory 22, and from this determines the time (address) of the data having the peak value. This is a waveform analysis circuit. The 81 calculation circuit 18 calculates the propagation time t from the time information obtained by the waveform analysis circuit 24, and calculates the speed of sound at a plurality of localities in the internal tissue of the subject based on the obtained propagation time t. In addition, it has a function of spatially averaging and outputting these. This calculation result is then displayed on the display 17. 25 is a system control means, which is mainly configured with a CPU (central processing unit: for example, a microprocessor). This system control means 25 controls the operation of the multiplexer 13, sets the delay time of the transmission delay circuit 15 and the reception delay circuit 1G, and controls the memory 22 according to a predetermined program.
It controls writing and reading of , and controls the operation of the calculation circuit 18 .

The transducers 7N to T128 are excited and emit ultrasonic pulses when voltage pulses are applied to them, and generate voltages when the ultrasonic pulses are incident on them. 128-element camera T1.
~ T128 is, for example, the element width a of each vibrator is 0.678
This is the pitch d −0,72m between the element centers.
128 elements are arranged linearly with + spacing. Electric signals are transmitted and received to and from each of these vibrators through the j-node line 12 within the cable 3. Further, the oscillator 21 generates an output signal based on a reference signal of, for example, IOM)Iz, and also divides the frequency of this signal to convert it into a 4 kHz rate pulse and outputs it.

This rate pulse passes through 32 transmission delay circuits 15 and then passes through 3 transmission delay circuits 15.
Two pulsers 14 are driven. The pulser 14 is a circuit that generates pulses for ultrasonic excitation driving, and the outputs of these 32 pulsers 14 are sent to the multiplexer 1, which is a switching circuit.
3, 128 camera elements T11. ~T128,
The signals are input to TI and T32 at the A end in a one-to-one correspondence.

Further, the transducers TI, to T128 are in contact with the body surface through the coating material of the probe 1, and the ultrasonic waves output from the transducer elements are propagated into the living body.

Standardly, the sound speed in living tissue is Co = 1530 [m/s]
Then, in order to radiate the ultrasonic beam in the 00 direction, the delay time between adjacent elements τ0τo=(d/Co)・sin
The transmission delay circuit 15 is set so that θo.=(2>), and each element is driven with such a delay time difference.

That is, PDI -0, PD2 = τo, PD3-2
τ0, ·p [) Gives a delay time of 32−32τ0.

If the sound velocity in the living tissue is Co, the ultrasonic beam will travel in the θ0 direction, but it is generally not limited to Co and has a different value C. The propagation direction θ of the ultrasonic wave at this time is sinθ/C-5inθo/Co according to Snell's law.
- The value shown in (3) is obtained.

After emitting the ultrasonic pulse, the multiplexer 13 transmits the vibrating element T97. ~The ultrasonic reflected wave signals received at T128 are synthesized after receiving the same delay as in the case of transmission,
The signal is input to the receiving circuit 19. Here, the reception delay circuit 16
The delay times are RDI-31τ0, RD2-30τo,
・”-, RD31-τo1RD32-0.

In this way, even if the ultrasonic beam transmitted in the θ0 direction at the sonic speed Go has a sonic speed C in the living body and has directivity in the θ direction, the transducer element group T97. ~T128 has directivity in the θ direction, and θ
It will receive reflected waves from the direction. The received signal is amplified, detected, and logarithmically converted in the receiving circuit 19, and is also A/D
△/ at a predetermined sampling timing by the converter 20
The data is converted into D and stored in the memory 22. The address of the memory 22 is updated sequentially in synchronization with a 10Mth clock based on the timing of the rate pulse, and the address of the sample value of the received waveform stored in the memory 22 is updated in time from the ultrasonic pulse emission time, for example. They match exactly with an accuracy of 100 nS intervals. Therefore, from the address, the time when data at that address was obtained (the elapsed time from the time when the ultrasonic pulse was emitted) can be determined.

The beak field of the stored waveform shows the reflected wave from point P,
When the waveform analysis circuit 24 detects the peak value B (address), the propagation time t can be determined. Substituting the above equation (3) into equation (1), the sound speed C in the living body is C= VCo/(t −5inθo ) ・”
(4) becomes. Further, by substituting the equation (2) into the equation (4), C= y・/・τ0 (4') is obtained. Since V+d and τ0 are known, the calculation circuit 18 calculates the above (4') using the propagation time t obtained by measurement.
Calculate the formula to find the sound speed C, and display 17
Output to.

FIG. 9 is a time chart showing a measurement method mainly based on propagation time, in which an ultrasonic pulse is emitted at a time later than the falling edge of the rate pulse in (a). The pulse peak time is tl.

In this way, when there is a point reflector P at the intersection of the center of the transmitting beam and the receiving direction, the time t
A reflected wave having a peak at t2 is obtained, and t is determined as the time interval between t2 and tl.

It is possible to adjust the probe so that the blood vessel inside the needle is properly positioned at point P, but since the target is a living body, there is actually something equivalent to a point reflector at the intersection of the beams. This is rare.

Generally, when the observation site is, for example, the liver, the vicinity indicated by point P is a relatively uniform hepatic tissue. Therefore, the reflected wave from the vicinity of this point P becomes a relatively uniform reflected wave from the liver tissue. Since the ultrasonic beam has a thickness, among the reflected waves mentioned above, the one that reaches the earliest is the one that goes through the 11 points in Figure 9, and the one that arrives the latest is the one that goes through the 12 points. becomes. Therefore, the received waveform spans a period of time corresponding to the width from Pl to P2.

Therefore, the received waveform in this case spreads as shown in 91st ffi (b), and since the tissue is not completely uniform and is a living tissue, various scattered ultrasound waves are formed and interfere with each other. Since the signal is received including the resulting speckles, various random irregularities will occur in the waveform.

Therefore, since the peak value cannot be detected with this method, by moving the probe a little, the echo data is obtained by slightly shifting the position of the beam intersection within the needle, and these are added together to cancel out the noise component. Do it like this. In other words, since the unevenness of the waveform in (b) is considered to be random, the waveform becomes much clearer by changing the beam intersection and adding hundreds to thousands of times, or by performing peak hold processing. It will look like (C).

Next, the calculation circuit 18 calculates the propagation time t as t-t2-tl.

Now, using 3.5M)12 as the ultrasound frequency, V =
48 m, and if the ultrasonic beam is focused near the above-mentioned intersection P, the beam width near the point P (about 17% at the peak in transmission and reception) is about 21 M. At this time, the propagation time difference Δt between the one passing through 11 points and the one passing through 12 points is about 4.5 μs.

When C=Co, the ultrasound beam direction is θo
=30°, the propagation time t is approximately 62.7 μs. Since the measurement accuracy at time t2 of the peak value is considered to be less than 1/10 of Δt, the sound speed measurement error is theoretically 10 m.
/S or less.

The sound speed measured in this way is the path 4 and 5 in Figure 7.
This sound speed information is displayed on the display 11 together with an ultrasound B-mode image (tomographic image) near the liver, which is the examination site in this case, and is used for diagnosis.

The above method is for finding the average sound speed in the tissue near point P, but if the method in (a) above is further improved, it is also possible to measure the local sound speed. The method will be shown using FIG.

FIG. 11 is an explanatory diagram of a case where the ultrasonic wave transmitting/receiving surface 2 of the probe 1 is applied to the body surface of the crotch region and a normal electronic scan is performed on a cross section 32 of the liver. The B-mode brass 30 obtained by electronic scanning is displayed on the display 17, and the propagation path set for sound velocity measurement is also displayed superimposed on the B-mode image using a marker. 31 is the subject's fat and muscle layer; 32 is a cross section of the liver showing the liver parenchyma; 33 is the diaphragm; and 34 is an abnormality (for example, a tumor) within the liver.

There is no problem with the above method when measuring the average sound velocity in the liver parenchyma 32, but when measuring the local, that is, the abnormal tissue 3 inside the needle,
If you want to measure the speed of sound in 4 parts, use abnormal group 1134.
The average speed of sound in the liver 1fA 13, which includes the part, is disadvantageous.

In this case, the ultrasonic measurement point (the intersection position of the beam direction directions for both transmission and reception) is Pl, and the abnormal tissue 34 indicated by PO
The transmitting/receiving position of the ultrasonic beam is determined so that it is at the boundary W point between the parts. At this time, the above measurement point P1, PO with probe 1
The extension line position is O, and in the propagation path of the ultrasonic beam with 11 points as measurement points, the emission points of probe 1 are A and B, the input points are 8 and 0, and 90 points are measurement points. In the propagation path of the ultrasonic beam, the emission points are C and D, the incident point is D and Ol, and the above measurement point P1 with probe 1 and the extension line position of PO are O, and the propagation path passing through each of these points is (A-B, A→O, B→O, c-+o,
C40, D-0) r(7) transmission tlBV t(AS),
Rainbow (AO), t (BO), t (CD).

Find t (Go) and t (Do).

In addition, the round-trip ultrasonic propagation time between Pl and PO is tp,
APO is the ultrasonic propagation time between A and APO.

The ultrasonic propagation time between PO→B is POB, the ultrasonic propagation time between PO→O is poo, the ultrasonic propagation time between c→P1 is CPI, the ultrasonic propagation time between P1→DP1 is PI D
, let the ultrasonic propagation time between P1 → 0 be Plo, and this')
'i: Use rt(AB>.

t (AO), t (BO), t (CD).

gtlli t (,Co), t (Do). T
F) Ch, t (AS)-APOAPOB t (AO)-APO+ (t Q/2)+P
1 0t (BO)-BPO+ (t (1/2
)+P1 0t (CD)-CPI +PI
Dt (Co)-CPI +P1 0t (Do
)-DPI +P1 0... (5) From this, t2 can be found using the following equation.

tffi-[(t (AO)+t (80)-t (A
B)) - (t (Co) + t (Do) - t (CD))] ・= (6) Therefore,
If the distance between pi and po is xQ, the average speed of sound is (1, the distance between AB is yo, and the distance between co and yl is, then Cj2=2X℃/lR - (VO-yl)/(tR-tanθ)・...(7) The local sound speed C2 is determined as '
((C/Co) ・Sinθ0)... (9
) as an approximate formula. In reality, the ultrasound beam is refracted at the boundary with normal liver tissue, so equation (7) is not exact, but if the beam incidence on the boundary is close to perpendicular, the error will be small. Note that this error can also be corrected by calculation based on the angle of incidence.

In this way, the sound velocity information of the region of interest is obtained, and the text information (
In Fig. 11, C1 indicates the sound velocity in the liver parenchyma and C2 indicates the sound velocity in the abnormal region), and the B-mode image and the measured ultrasound propagation path are displayed on the display together with display markers. Save by recording a video.

This type of sound speed measurement is called a cross mode (or cross beam method) sound speed meter, but in the case of the method described above,
A, B, C, D in probe 1.

Propagation path for point 0 (A-8, A→O, B→O1C→
The propagation time in a total of six propagation paths (D, C→○, D-0) was measured to determine the local speed of sound. By measuring three paths for one measurement point in this way, we can measure the thickness of the abdominal wall (the thickness of the body surface and subcutaneous tissue) due to the ultrasonic beam entering obliquely and exiting obliquely. The accuracy is improved by reducing the influence of differences.

However, the thickness of the abdominal wall is not uniform, and the physical conditions during the outbound and return trips to the measurement point are also different, and this causes differences in the attenuation of sound waves and the measurement results on each route. Due to factors such as the influence of biological motion due to timing deviations, each measurement 1a includes an error. In the above method, this error is reduced by averaging the caulking using the measured values of various routes, but contrary to the original purpose, in the case of the above three route method, especially B
If there is a lack of measurement along the paths from A to D and from D to C, the average will be statistically non-uniform due to old asymmetric measurements, and therefore gII'H cannot reduce the above error.

Therefore, for each ultrasonic beam transmission/reception path used for the above-mentioned measurement of the object, control is performed so that the above-mentioned detection measurement is performed at least once each with the outgoing direction and the returning direction as a set, and thereby - per path, Perform detection measurements an even number of times (at least two round trips) with the transmitting and receiving directions reversed to ensure symmetrical measurements, and calculate the average ultrasonic propagation velocity based on the information obtained from these detection measurements. A cross-mode sound velocity measurement method using a symmetric measurement method has also been proposed, which aims to reduce errors by obtaining a uniform average.

Specifically, as shown in Figure 3, this method is based on the localization of the abnormal part contained within the reflection points (measurement points) Ptt and Pt2 at the upper boundary and the reflection point eA (measurement point) Pao at the lower boundary. When measuring the speed of sound, the ultrasonic beam transmission and reception path is (1
) A-) PG a-8, (21A4P1 +
-C, (3) B-+Pa O-+A, [
4,) Pt 2→D four routes are taken. That is, each of the A and B positions of the probe 1 is used as an ultrasonic beam transmitting position and also as a receiving position. Then, the wave is transmitted from the 8th position,
The wave reflected at Pao is received at position B, then transmitted from position A, the wave reflected at Plt is received at position C, then transmitted from position 8, and the wave reflected at PIIO is transmitted at position 8. By switching the transmission and reception such that the wave is received at position B, then transmitted from position B, and the wave reflected at position D is received at position D, the measurement path is symmetrical. The direction of beam transmission and reception is made to be at the same angle θ.

According to this, detection measurements are performed at least twice per route, on the outbound and return trips, resulting in symmetrical measurements, and the average ultrasonic propagation velocity is determined based on the information obtained from these detection measurements, so statistical analysis is performed. This results in a uniform average, which makes it possible to reduce errors.

Such a loss mode sound velocity measurement function is built into an ultrasound diagnostic device, and is usually used to measure ultrasound images (for example, B-mode images).
displayed on the display.

This situation is shown in FIG. In the figure, 40 is an 8-mode image of the subject's region of interest measured in real time, and 41
is a beam bus marker indicating the route of the set beam bus for the cross-mode sound velocity measurement in this region of interest; 42 is a real-time A-mode image of each beam bus route obtained by the cross-mode sound velocity measurement; 43
is the beam obtained by the above cross-mode sound velocity measurement.
Each sound speed value for each bus route, 44 is a direct change diagram of the average sound speed of the target region obtained based on each sound speed value for each beam bus route. The beam bus marker 41 indicates the routes (1) to (4) above, and also indicates the speed of sound [
33 is the sound velocity 1a of the route (1) above, Vl, the sound velocity value of the route (2), v2, the sound velocity value of the route (3), v3, and the sound velocity value of the route (4). The sound speed value of the route is displayed in numerals as ■4.

Note that ■ is the average sound speed value of these four routes. Further, the above average sound 3Ni value change diagram 44 shows the time change of this average sound speed value. In addition, the A mode elephant 42 is the root (1) ζ(3 as 81, B3 as the root (2)
) and (4) are 32. It is displayed as B4.

In displaying such an image, the B mode image 40 is rewritten in real time under the control of the system-based D means, and in between, the cross mode of the four routes mentioned above is Calculation circuit 18 that measures the speed of sound
Calculate and display the measurement results. And △
The mode image is displayed using echoes obtained by cross-mode sound velocity measurements.

I mean, what! Collects 8-mode image data for every 1ifili and displays it in sequential updates, and displays the B-mode image in real time by inserting cross-mode sound velocity measurement every time the collection of B-mode image data for several screens is completed. The speed of sound is measured at a desired position while viewing this 8-mode garden.

By the way, J
5, the ultrasonic beam is scattered by various scatterers during the transmission and reception paths, and interference (
speckle), the measurement signal fluctuates greatly.

Then, from this fluctuating measurement signal, y49 diagram < d)
As in, find the position of the peak (direction), and calculate the time t of the above
However, the accuracy of the measurement results varies greatly depending on the position of the calculated peak value. This directly affects the accuracy, stability, and reproducibility of the estimated sound speed. In other words, if peak positions are detected using data with large speckles, peak values of data such as a and b in Figure 14 will be detected, and no matter how many times the same part is measured, it will show different values. This leaves us with the third problem of measurement instability.

Therefore, in order to stabilize the signal with large fluctuations, the first
As shown in FIG. 3, many sample signals 81. ~3n is obtained, and the average Sa is taken to reduce speckles.

By the way, speckles become larger when a non-uniform substance such as a blood vessel enters the measurement route for sound velocity measurement. Because the probe is supported by the operator's hand and the subject moves due to breathing, the probe is often affected by heterogeneous substances like q. Therefore, there is no way to confirm the positional relationship between the wave transmission and reception path passing through the subject and blood vessels, etc., so even if the sound speed is measured, it is unclear to what extent it is affected by the inhomogeneous medium. However, the reliability of the measured values was insufficient. That is, real-time B
Even though it is displaying the mode image, it collects several screens worth of B-mode image data, updates it sequentially, and displays the cross mode every time the data collection of the 8-mode image for several screens is completed. Because the sound speed measurement is folded in, even if a marker for the sound speed measurement path is displayed on the real-time B-mode image, it can be said that the time dimension of the B-mode image and the sound speed measurement are completely different after all. , Due to the above-mentioned movement, it is virtually impossible to know which position of the subject the sound velocity is being measured through.

(Problem to be solved by the invention) In this way, in the conventional method, the data collection time of the B-mode image and the time of sound velocity measurement are completely different in terms of time.
Even if the sound velocity measurement route is displayed with a marker on the B-mode image, if the measurement route for the subject changes due to body movement of the subject or deviation of the hand-held probe, the actual measurement route and the B-mode image may be Since the positional correspondence of the speckles is not known, even if there is a blood vessel or the like that is a major cause of speckles in the measurement route, it is not known in reality and measurement accuracy cannot be ensured.

Therefore, an object of the present invention is to accurately determine the location of the measurement route on the subject in which the sound speed is being measured in an ultrasonic diagnostic device that has a sound speed measurement function using the beam crossing method (cross mode). 11 Ultrasonic diagnostic V equipment with cross mode sound speed measurement function that allows you to grasp the reliability of the sound speed measurement value.
It's about offering one meal.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention uses a probe configured by arranging a real number of ultrasonic vibrating elements in parallel, and uses adjacent ultrasonic vibrating elements of the probe. The number of TLs is grouped together and an ultrasound beam is transmitted to the target area of the subject through a transmission path in a predetermined direction, and the ultrasound beam is transmitted at the target area through a reception path in a predetermined direction that intersects with the transmission path. In order to receive the beam, ultrasonic Σ reception is performed using a group of ultrasonic vibrating elements for transmitting and receiving different ultrasonic beams, and the peak of the reflected wave from the target area is detected and its transmission is performed. At least the above-mentioned sound speed measurement is carried out in an ultrasonic diagnostic ￥R equipment equipped with a sound speed measurement function that obtains information on the ultrasonic propagation velocity of the target area and provides it for diagnosis by measuring the time required from the wave to the peak reception. In addition to switching between the sound velocity measurement mode and the ultrasound @12 side mode for obtaining an ultrasound B-mode image, the probe is used to collect sound velocity measurement data in the middle of each scan to collect one screen's worth of B-mode image forming data. A control means for transmitting and receiving ultrasonic waves in order to mix and match scanning for the purpose of scanning, and displaying markers at corresponding positions on the ultrasonic B-mode image displayed on the display device to indicate the ultrasonic wave transmission and reception path during sound velocity measurement. When measuring the speed of sound, the peak position of the received signal from the target area is determined based on data obtained by averaging the 141:iB sonic received signals for each transmission and reception path, and the ultrasonic propagation time is obtained. It is configured by providing an analysis means.

(Function) In such a configuration, when cross-mode sound velocity measurement is started, the control means starts scanning for B-mode clean formation, and during each scan to obtain one screen of B-mode images,
That is, one illumination is performed so that, for example, one (or several) sound speed measurements for cross-mode sound speed measurements are performed at predetermined timings. On the other hand, the ultrasonic beam transmission/reception path for measuring the speed of sound is displayed with a marker at the corresponding position on the ultrasonic B-mode image. Therefore, the B-mode image and the sound velocity measurement are performed at the same timing, and the B-mode image and the sound velocity measurement route correspond accurately to reality. Therefore, it is now possible to know where on the subject the sound velocity measurement is being performed, and the ultrasonic transmission and reception route (it
It is possible to instantly know whether there is a blood vessel, etc. in the measurement route.

In this way, the received signals for sound velocity measurement obtained by sequentially repeating wave transmission and reception with sound velocity measurement mixed in during data collection for each frame of the B-mode image are added and averaged, and the received signal at the intersection is The ultrasonic propagation time is calculated from the time information from the start of wave transmission to this peak position, and is used to measure the speed of sound.

In this way, in heavy equipment 0M, the display data of the B-mode image can be collected by intermixing the ultrasonic beam scanning for measuring the sound velocity with the ultrasonic beam scanning for displaying the 8-mode image for each screen. By making the data collection for sound velocity and sound velocity measurement virtually at the same timing, even if the probe moves or the subject moves, the B-mode image and the sound velocity measurement route will remain on the displayed B-mode image. Since they match correctly, the relationship between the sound velocity measurement route and the subject can be clearly seen by looking at the B-mode image and the marker for the sound velocity measurement route. It will be possible to grasp the extent to which the measurement route has changed.

Therefore, by taking this into consideration when reading the sound velocity measurement value, highly accurate sound velocity measurement can be performed.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the main structure of this device. In the figure, 1 is a probe, 12 is a lead wire, 13 is a multiplexer, 14 is a pulser, 15 is a transmission delay circuit, 16 is a reception delay circuit, 17 is a display, 19 is a reception circuit, 2
0 is an A/D converter, 21 is a clock oscillator, 22 is a memory, 23 is a processing circuit, and 24 is a waveform analysis circuit. These are basically the same reference numerals in FIG. 8 as explained earlier.
It is the same as the one with the same name, so it will not be explained again here. 18 is a calculation circuit that performs sound velocity calculation, average value calculation, etc. based on the output of the A/D converter 20; 25A;
is a system control means and controls the entire system. , 26 is a VJ change switch, and reception delay circuit 1
Cross-mode sound velocity measurement side of the combined output of 6 and ultrasonic wave B
It is used to obtain a mode image and to select and switch the supply route to the ultrasonic device side B. Reference numeral 27 denotes a receiving circuit on the ultrasonic device side, which performs amplification, detection, filtering, logarithmic conversion, etc. of the received signal. 2B is an A/D converter, which converts the output of the receiving circuit 27 into a digital signal. Reference numeral 29 denotes a marker generator, which generates image data (marker) for displaying the measurement route (beam bus route) of the cross-mode sound velocity measurement. 3
0 is a digital scan converter, which has a frame memory and sequentially updates and stores the digital data output from the A/D converter 28 at an address corresponding to the beam position where the data is collected. At the same time, readout is performed in accordance with the scanning timing of the display 17, so that the acquisition timing of the ultrasound image and the display 17 are
By interposing this frame memory, the difference in display timing between the two images can be converted without any problem.

Also, the output of the marker generator 29 is this digital signal.
The B-mode image is written on the frame memory of the scan converter 30 at a position corresponding to the measurement route of the cross-mode sound velocity measurement.

The memory 22 also updates and stores the data of the A-mode image. Furthermore, although not shown, the display 17 has a video RAM which is a display image memory, and displays graphs of the sound speed data, A-mode image, change pattern of the average sound speed, etc. calculated by the calculation circuit 18. The control means 25A controls the data to be stored in a predetermined layout and in a predetermined format. The image data on this video RAM and the digital scan converter 3o
Display an image based on the output of .

This device is basically the same as the one explained in the prior art section regarding cross-mode sound velocity measurement, but in contrast to the configuration shown in FIG.
The function is set as follows. The system control means 25A used in this apparatus is the same as the conventional system in that it is mainly composed of a CPIJ (central processing unit d; for example, a microprocessor). This system control means 25A controls the operation of the multiplexer 13, sets the delay time of the transmission delay circuit 15 and reception delay circuit 16, controls writing and reading of the memory 22, and analyzes the waveform according to a predetermined program. Operation control of the circuit 24 and the calculation circuit 18 and changeover control of the changeover switch 26, and during cross mode sound velocity measurement, conduct ultrasonic scanning for B mode and measure sound velocity along the measurement route set during B mode scanning. It controls scan switching for mixing, marker output control of the marker generator 29, etc. When measuring the sound speed, the ultrasonic transmission and reception for cross-mode sound speed measurement are mixed and controlled at predetermined timings while the ultrasonic scan is being executed for each frame for the B mode, and the real-time B mode Display and sound velocity measurement are performed, and the sound velocity measurement calculation and the display of the result and the calculation of the average sound velocity of the entire beam bus and its block l ~ display are displayed in rows. In other words, in this system, as shown in Figure 2, ultrasonic If seven vibration elements are used as a group for transmitting and receiving waves,
For example, the ultrasonic transducers T1 to TI perform ultrasonic transmission/reception UT and tJR in the linear electronic scan mode (the changeover switch 26 is switched to Bi mode), and then the ultrasonic transducers T2 to T8 perform ultrasonic scanning by linear electronic scanning. Sonic waves are transmitted and received, and then ultrasonic waves are transmitted and received by linear electronic scanning using the lower ultrasonic vibration elements 3 to T9. In this way the first
Waves are transmitted and received by linear electronic scanning while shifting the vibrating element by one pitch in the order of 1st and 4th times (indicated by UTl, URLl, and UT4.UR4 in the figure), and here the sound speed measurement mode (switching For example, the switch 26 is switched to the answer terminal) to connect the ultrasonic vibration element lower 8 to T.
Transmission (tJT5) is performed at a transmission angle θ according to 14, and reception (LIR5) is performed at a reception angle (−〇) by, for example, the ultrasonic transducer elements T116 to T122.

Next, return to linear electronic scanning again to transmit and receive ultrasonic waves (UT6゜UR6
), and then ultrasonic transmission and reception in linear electronic scan mode by ultrasonic transducer elements T6 to T11 (LIT7.UR7
), etc. Transmission and reception (UT9.UR9) is performed by linear electronic scanning using T8 to T14, and here, the mode is changed to sound velocity measurement mode to transmit waves using ultrasonic transducer elements T8 to T14. Transmission by angle θ (UTlo), reception angle by ultrasonic vibration elements T116 to T122 (-〇)
(tJRlo) and returns to the linear electronic scan mode again. And ultrasonic vibration elements T9 to T1
4 transmission and reception (UTll, URII), ultrasonic vibration elements T10 to T15 transmission and reception (UT12°UR12),
... Transmission and reception by ultrasonic transducer elements TI2 to TI7 (IJT
14. IJR14), and here again, the mode is changed to the ultrasonic sound velocity measurement mode, and the ultrasonic vibration elements T8 to T14 transmit waves at the transmission angle θ (UT15), and the ultrasonic vibration element T11G
~ Reception at reception angle (-θ) by T122 (UR15)
Then, the system returns to the linear electronic scan mode again, and performs linear single scan mode ultrasonic transmission and reception by shifting the vibrating element one pitch at a time from the previous position.

In this way, while performing ultrasonic scanning for one frame from the left end to the right end of the probe 1 in the linear electronic scan, the system control means 25A controls so as to intermix sound velocity measurements at predetermined timings. .

Note that the A-mode display is performed based on the measurement data on each beam bus obtained by the cross-mode sound velocity measurement performed during the B-mode scan.

This is performed in the form of an A-mode image display, an average A-mode image display, an average sound speed change diagram of one selected beam bus, or a local sound speed change diagram.

Further, regarding the above-mentioned sound velocity measurement mixed during the B-mode linear electronic scan, if, for example, a cross-mode symmetric measurement method is used, the operation of the multiplexer 13 is controlled as follows.

That is, as shown in Fig. 3, this device measures the pH and local sound velocity at the reflection point (measurement point) at the upper boundary and the abnormal part included in the reflection point (measurement point) Pa o at the lower boundary. For this purpose, the ultrasonic beam transmission and reception path is set to A-IPa.
o-+B, A-+PJ 1-+C, B-+Pa 0-
IA, B-+Pt 2-+D so that there are 4 routes,
Ru. That is, each of the A and 8th positions of the probe 1 is used as an ultrasonic beam transmitting position and also as a receiving position. Then, it sends a wave from position A, receives what is reflected by POO at the 8th time, and then sends a wave from position A,
Receive the - reflected at Ps't at position C, then transmit from the 8th position, receive what was reflected at Po11 at position A, then transmit from the 8th position, and transmit from PI3. What is reflected is 0
By switching the transmission and reception in such a way that the signal is received at
The directional directions of the ultrasonic beams in the transmission and reception directions are made to be at the same angle θ. Then, each time you enter the sound speed measurement mode, you can select to measure one of the four routes in turn, or change to the next other route every time you measure the same route several times. It shall be executed in an appropriate order, such as

Next, the operation of the device having such a configuration will be explained.

In this embodiment, the cross-mode sound velocity measurement is performed using four routes B1, 82, and 83 as shown in FIG.

84, and each reflection point is set in advance by the operator at the optimal depth (beam intersection) close to the target area by referring to the B-mode ultrasound image. shall be. Further, referring to the B-mode ultrasound image, the operator sets cross-mode sound velocity measurement rules 1 to 1.

As a result, the system control means 25A controls the marker generator 2.
9 to generate image data (marker) for displaying the measurement route of the cross mode sound velocity measurement set above in a visible form including the moving area. Marker generation B2
Since the output of 9 is written in the B mode image on the frame memory of the digital scan converter 30 at a position corresponding to the measurement route of the cross mode sound velocity measurement, it is set on the display 17 together with the current 8 mode image. The measurement route for cross mode sound velocity measurement is displayed with a marker.

Therefore, the operator can know in advance whether blood vessels or the like will not enter the measurement route, and if so, to what extent, and can change the settings if there is a problem.

Once the measurement route has been set in this way, the operator then issues a measurement command to start sound velocity measurement.

This is done as follows. That is, the changeover switch 26 is temporarily switched from the terminal B side to the X side at a predetermined timing between the ultrasonic electronic scans in the B mode, and the sound velocity measurement is performed on the measurement route at the set starting point position. .

To explain specifically, first, the system control means 2
The selector switch 26 is switched to the terminal B side under the control of the delay circuit 15.5A, and the multiplexer 13 is selected for linear electronic scanning, and the delay circuit 15.
16 delay times are set for linear electronic scanning, and ultrasonic waves are transmitted and received from the 'Etu child group selected by the multiplexer 13 using these delay times. The combined output of this received signal is amplified and detected by the receiving circuit 27, and then a low-pass filter (cutoff It is filtered by a frequency (about IMHz). The data is then converted into digital data by the A/D converter 28 and input to the digital scan converter 30, and the data is stored in the frame memory location of the digital scan converter 30 corresponding to the ultrasound scan position. Such ultrasonic scans are sequentially performed while sequentially shifting the scan position, and an ultrasonic B-mode image is formed in the digital scan converter 30. In addition, the beam bus marker for cross mode sound velocity measurement set by the marker generator 29 is output, and the marker is placed at the position corresponding to the cross mode sound velocity measurement position in the frame memory of the digital scan converter 30. is stored. Digital scan converter 30 thus formed
The image data on the frame memory of
The data is read out in accordance with the scanning of the image data, and is provided to the display 17 for display.

At a predetermined timing during the linear electronic scan position in each frame, the system ilJ 111 means 25A switches the changeover switch 2G to mix the sound speed 51 measurements.
Switch to terminal X side. Then, cross mode sound velocity measurement begins. This sound velocity measurement is first performed along route 81 at the above-determined position.

That is, under the control of the system control means 25A,
The delay time of the transmission/reception delay circuit 15 is set.

The delay time difference τ0 between adjacent camera elements is τo = (d/Co) S i n8o (
The relationship is set so as to satisfy the above equation (2). Under the control of the system control means 25A, a predetermined number of transmitting vibration elements belonging to point A of the probe 1 are connected to the output ends of the corresponding pulsers 14 by the switching operation of the multiplexer 13.

For example, if the predetermined number of transmitting transducer elements belonging to the eight points of the probe 1 (see FIG. 3) is 32, then the transducer group Tl, ~T32 and the output end of the pulser 14 are Connected.

Further, a rate pulse is generated by the clock oscillator 21 and is input to the pulser 14 via the transmission delay circuit 15. Then, from the pulser 14, the corresponding transmission delay circuit 1
The excitation pulse is outputted at a timing shifted by a delay time of 5, and is input to the corresponding transducer of the pulser among the transducers TI to T32, and the transducer generates an ultrasonic wave. Then, the ultrasonic beam is transmitted in a predetermined direction θ determined by the delay time.

On the other hand, under the control of the system control means 25A, the delay time of the transmission delay circuit 16 is set, and under the control of the system control means 25A, the point B of the probe 1 (
By switching the multiplexer 13, a predetermined number of receiving vibration elements belonging to the corresponding delay circuit 1
Connected to the G input end.

Here, since there are 32 transmitting transducer elements, the 32 transducer groups T91° to T12 bend at point B of the probe 1.
8 and the input terminal of the reception delay circuit 16 are connected.

As a result, the ultrasonic beam transmitted toward the subject from the transducer group located at point A of probe 1, the reflected portion at point Poo is received by the transducer group belonging to point B of probe 1. , the echoes are given the same time difference as in the case of transmission by the receiving delay circuit 16, and then synthesized and output.

The received echo synthesis output from this receiving delay circuit 1G is:
The signal is amplified and detected by the receiving circuit 19 and filtered (filtering during sound velocity measurement is to smooth waveform distortion caused by speckle noise and improve measurement reproducibility, and a low-pass filter with a cutoff frequency of about 100 kHz is used. used), then A/D converter 2
0, it is converted into a digital value and written into the memory 22. In the memory 22, the address is updated at a predetermined timing every time an ultrasonic beam is transmitted by the clock signal output from the clock oscillator 20, and writing control is performed by the system control means 25A to record the echo from the measurement point. is stored in a form that corresponds to time. This becomes A-mode image data.

The above-mentioned ultrasonic transmission and reception is performed multiple times by the transducer groups belonging to each of the points A and B of the probe 1, using the number of times of ultrasonic transmission and reception in the mode that will occur from next time onwards. Measurement is performed, and the received echoes obtained through this measurement are averaged by the action of the processing circuit 23 with respect to those of the same route (if 81, those of B1).

This suppresses fluctuations.

When this work is completed, the system control means 25A switches the changeover switch 2G to the terminal B side again, and starts collecting B-mode images. Then, at a predetermined timing during execution of the linear electronic scan for obtaining the B-mode image, the system control means 25A switches the changeover switch 26 to the terminal X side, and moves on to cross-mode sound velocity measurement on the second route. Then, the multiplexer 13 is operated under the control of the system control means 25A, and this time the transducer group 0 of the probe 1 is changed to the transducer group belonging to point B on the route of the starting point position.
A predetermined number of transducer groups belonging to a point are connected to the input terminals of the corresponding reception delay circuits 16, and a predetermined number of transducer groups belonging to a point A of the probe 1 are connected to the corresponding pulsers 14, respectively. Connected. Then, the reflected component at point P1t of the ultrasonic wave transmitted from the transducer group belonging to point A of probe 1 is received by the same number of transducer groups belonging to point 0 of probe 1 as at the time of transmission. The reception echoes are given the same time difference as in the case of transmission by the reception delay circuit 16, and then synthesized and output.

The combined output of the received echoes is amplified and detected by the receiving circuit 19 in the same way as in the case described above, and after filtering by the low-pass filter, the combined output of the received echoes is transmitted from the ultrasonic wave on the route 82 to the time t2 of reception. Provided for measurement.

When this work is completed, the system control means 25A switches the changeover switch 2G to the terminal B side again, and restarts the interrupted collection of B-mode images. Then, at a predetermined timing, the system control means 25A switches the changeover switch 26 to the terminal xl.
I! Switch to lJ, B3 in the route of the above starting point position
Let's move on to measuring the cross-mode sound speed along the route. Then,
The multiplexer 13 is operated by tllllll of the system control means 25A, and this time, instead of the transducer group belonging to the point A, it is changed to the transducer group belonging to the B point of the block 0-71, and a predetermined number (the previous Transmitting transducer group T97° to T128 (32 elements in the example) and the corresponding balsa 14
Further, instead of the transducer group belonging to point 0, a transducer group of 32 elements belonging to point A of probe 1 is connected to the receiving delay circuit 16. And probe 1
An ultrasonic wave is transmitted from the transducer group belonging to point B of the probe 1, and a reflected component of the transmitted ultrasonic wave at point Poo is received by the transducer group belonging to point A of the probe 1. The reception echoes are given the same time difference as in the case of transmission by the reception delay circuit 16, and then synthesized and output.

The combined output of the received echoes is amplified, detected, and filtered by the receiving circuit 19 in the same way as in the above case, and then outputted to B3.
The time from ultrasonic transmission to reception on the route fl
Used for lt3 measurement.

When this work is completed, the system control means 25A switches the selector switch 2G to the terminal B side again, and
Collect mode images again. Then, at a predetermined timing, the system control means 25A switches the selector switch 26 to the terminal X side, and moves to the cross mode sound velocity measurement on the route B4.

The multiplexer 1 is controlled by the system control means 25A.
3 operates, and this time A in the route of the above starting point position
Instead of the transducer group belonging to the point D, the predetermined number of transducer groups belonging to the point D of the probe 1 are connected to the input terminals of the reception delay circuits 1G corresponding to the respective ones.
Each of the predetermined number of oscillator groups belonging to a point is connected to a corresponding pulsar 14.
connected to.

Then, the transducer group and the input terminal of the receiving delay circuit 16 are connected. Then, when ultrasonic waves are transmitted from the transducer group belonging to the eight points of probe 1, the reflected component of the transmitted ultrasonic wave at point P12 is reflected by the transducer group covering point D of probe 0-11. The waves are received by

Then, the received echo is transmitted by the receiving delay circuit 16.
After being given the same time difference as in the case of wave transmission, the signals are combined and output. The combined output of this received echo is shown above)! After being amplified, detected, and filtered by the receiving circuit 19 in the same way as in the case of 1, the ultrasonic wave is used to measure the time t4 from transmitting the ultrasonic wave on the route B4 to receiving the wave.

When this work is completed, the system control means 25A switches the changeover switch 26 to the terminal B side again, and restarts the interrupted collection of B-mode images. Then, at a predetermined timing, the system control means 25A switches the changeover switch 26 to the terminal X0.
81 at a new position where the ultrasonic transducer is moved by, for example, one pitch with respect to the route of the above starting point position.
Let's move on to measuring the cross-mode sound speed along the route.

A plurality of echo signals collected by repeating such an operation are obtained as an average value of the respective echo signals at 4 lous (81 to B4) as shown in Fig. 6.In addition, data obtained by linear scanning Real-time B
A mode image is displayed.

In this way, the measured values for each measurement route are averaged and stored. This stored data is read out from the memory 22, and the peak position is determined by the waveform analysis circuit 24.

Then, information on the address where the data corresponding to the determined peak position is stored is sent to the calculation circuit 18 as time information. Then, based on this, the calculation circuit 18 calculates B1,
B2.83.84 Time t1. from transmission of ultrasonic waves to the above peak position for each route. t2. t3. t4 is calculated. After that, the sound speed values Vl and V2 for each route are further
, V3, V4, and the average sound velocity value (■) and local sound velocity value in the entire beam bus, etc., are calculated and displayed on the display 17.

In this way, this device measures the speed of sound at 8
It is designed to be mixed during electronic scanning to collect data for mode images. Therefore, even when measuring the speed of sound, the B-mode image, the sound speed measurement route, the measured sound speed value,
The average sound speed time change chart is updated and displayed in sequence.

An example of the display on the display 17 is shown in FIG. In the figure, 51 is a B-mode image, and 52 is the above-mentioned cross at this region of interest.
A beam bus marker indicating the beam bus route for setting the mode sound speed measurement, 53 is an A mode image for each beam bus route obtained by the cross mode sound speed measurement,
54 is each sound speed value for each beam bus route that has been subtracted by 1 by the above cross mode sound speed measurement, and 55 is the average sound speed value change of the target area calculated based on each sound speed value for each beam bus route. It is a diagram. The beam bus marker 52 indicates the movement area of the route from Bl to B4, and
Also, the sound speed of 11154 is among these routes, B1 above.
The sound speed value of the route of above B2 is V2, the sound speed value of the above B3 route is v3, the sound speed value of the above B4 route is V4, the average sound speed value at the local (beam intersection) is VL. It is displayed numerically as . In addition, ■ indicates these 4
This is the average sound speed value of the route. Also, 56 is the variance value, 57
shows the average A-mode image of each route. Further, the average sound speed value change diagram 55 shows the time change of this average sound speed value. Further, in the A mode image 53, those of routes B1 and B3 are displayed as Bi and B3, and those of routes B2 and 84 are displayed as 82 and B4.

In addition, in the ultrasonic wave transmission and reception in the cross-mode sound velocity measurement described above, this device detects the movement distance of the center position in the transducer arrangement direction of the transducer group belonging to point A and the transducer group belonging to point D, and the moving distance of the center position of the transducer group belonging to point A and the transducer group belonging to point D. As shown in FIG. 3, the moving distances of the center positions of the vibrator group that deteriorates and the vibrator group that belongs to the 0 point in the vibrator arrangement direction are the same distance Δy.

Further, the deflection angle θ of the ultrasonic beam is set to θ0 in both cases, and is made equal.

Therefore, this results in point P1! and point P12 are in a line-symmetrical positional relationship with respect to a line that passes through point Poo and is perpendicular to the ultrasound transmission/reception wave surface of probe 1, and the distance therebetween is Δy.

Here, point Poo, point P111 and point P12 are ultrasound reflection points in the internal tissue of the subject, but at the same time A of probe 1
It means the intersection of the ultrasonic transmission/reception directional directions by the transducer groups belonging to point B, point B, point 0, and point D, respectively.

Therefore, the time tl obtained by the above-mentioned ultrasonic wave transmission and reception,
~t4 is used to cause the calculation circuit 18 to perform the following operation.

Δt=((tl-t2)+(t3-t4)]/2=(
(tl +t3)/2)-((t2+t4)/
21... (10) Δt obtained by executing the calculation of equation (10) is
The estimated propagation time of the ultrasonic wave propagating along the path between point pH→point Poo→point P12 is 1M.

Therefore, the calculation circuit 18 calculates the average sound speed CA of the ultrasonic waves propagating along the path between point P11→point Poo'→point PL2 using the following equation.

CA=(Δy-co)/(Δt-8inθ0)...(
11) The average sound velocity calculated by this equation (11) is calculated locally in the internal tissue of the subject (in this case, points P1t and Poo).

represents the speed of sound in the region (including PI3).

In this way, it is possible to calculate the sound velocity locally in the internal tissue of the subject from the reflected components of the ultrasound waves at the 23 points Pit, POO, and PI. 13, by appropriately switching and changing the intersection position of the directional directions in the transmission and reception of ultrasonic waves, it is possible to determine the sound velocity at a m-number locality in the internal tissue of the subject without changing the deflection angle θ.

FIG. 3 is a diagram showing a region where the local sound speed can be measured by switching the vibrator. Generally, the delay time that determines the pointing direction is increased by 1q depending on the delay element, but this delay element has a limited range of delay times that can be set. Therefore, since the above-mentioned intersection point is specified, the marker generator 29 is configured to output a beam path passing through this possible intersection point tiLa as a marker, and when a measurement route is set, Select and output the beam bus as a marker.

31 in the figure is the measurable area of the local sound velocity, and this f11
* Indicated with the symbol POO in 31, ~P71 "・
” is the intersection point of the ultrasonic transmission/reception directional directions.

In this case, (Poo, Ps t
.

PI3), <Plt, P21, P22).

(PI3.P22.P21), (P21.Plt.

P32), (P22.P32.P33).

(Like P23 , P33 , P34 >,...
In accordance with the abnormal area to be measured, a second point of intersection is located in a line-symmetrical positional relationship with respect to a line that passes through the first point of intersection and is perpendicular to the ultrasound transmission/reception wave surface of the probe 1. ．． Select a combination of three reflection points at the third intersection, and
By performing the above measurement on the filtered reflected waves using the ultrasonic beam passing through the above-mentioned routes at the two intersection points, and calculating the average sound speed by calculating equation (11), the desired It is possible to obtain the local average sound speed distribution.

The desired local sound speed value calculated by the calculation circuit 18 can also be displayed as a sound speed distribution on the display 17 after being subjected to brightness modulation or color modulation.

In this device, the averaged values are plotted and displayed graphically, but the following averaging may also be performed. This averaging (unsampled averaging) is performed using the following equation.

C-(1/N), nc...(12)
Here, C is the unsampled averaged sound velocity information, and N is the number of combinations of intersection points used to calculate the local sound velocity, which is 3 in this embodiment.

Also, unsample averaging can be performed as follows.

That is, by combining each of the three intersection points, the ultrasonic propagation time is first unsampled and averaged, and using the average result, formula (14) is calculated to obtain the sound speed value C.

△ Δt-(1/N>, E (Δti) ... (1
3)...(14) The unsampled average result of the sound velocity values thus obtained is displayed on the display 17 as shown in FIG.

Also, by using the collected data of all the ultrasonic beam transmission and reception paths collected during the sound velocity measurement mode to obtain the ultrasonic propagation velocity information, the sound velocity measurement (direction) at each loop i- is obtained, and this is displayed on the display 17. In addition, an A-mode image is generated from the data stored in the memory 22, and an A-mode image (9 is input to the calculation circuit 18) using the average value from the same route is displayed. are determined and given to the display 17 and displayed at a predetermined position in a predetermined format as shown in FIG.

As explained above, the present invention combines the ultrasonic scanning for measuring the speed of sound during the ultrasonic beam scanning for displaying the B-mode image for each screen, and collects the display data of the B-mode image. This allows the data collection for sound speed measurement to occur at virtually the same timing. As a result, even if the probe moves or the subject moves, the B-mode image and the sound velocity measurement route match correctly on the displayed B-mode image, so the B-mode image and the marker for the sound velocity measurement route Since the relationship between the sound velocity measurement route and the subject can be clearly seen by looking at the image, it is possible to grasp the extent to which blood vessels, etc., which are the source of high-frequency noise components such as speckles, are involved in the measurement route. Become. Therefore, by taking this into consideration when reading the sound velocity measurement value, highly accurate sound velocity measurement can be performed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and shown in the drawings, and the gist thereof remains unchanged. It can be implemented with appropriate modifications within the scope.

〔Effect of the invention〕

As described above, according to the present invention, in an ultrasonic diagnostic apparatus having a cross-mode sound velocity measurement function, display data collection of a B-mode image and data collection for sound velocity measurement are made to occur at virtually the same timing. Therefore, even if the probe moves or the subject moves, the B-mode image and the sound velocity measurement route correctly match on the displayed B-mode image, so the B-mode image and the marker for the sound velocity measurement rule l- can be By looking at it, you can clearly see the relationship between the sound velocity measurement route and the subject, so you can grasp the extent to which blood vessels, etc., which are the source of high-frequency noise components such as speckles, are involved in the measurement route. By taking this into account when reading the sound velocity measurement value, it is possible to measure the sound velocity with high accuracy, and therefore it is possible to provide a highly reliable ultrasonic diagnostic apparatus with a cross mode sound velocity open side function.

[Brief explanation of drawings]

The first factor is a block diagram showing an embodiment of the present invention,
2 and 3 are diagrams for explaining the present invention in detail,
FIG. 4 is a diagram for explaining the measurement point setting area in the probe of this device, FIG. 5 is a diagram showing an example of the display display of this device, FIG. 6 is a diagram for explaining the caulking average,
Figure 7 is a diagram showing the principle of cross mode sound velocity measurement, Figure 8
The figure is a block diagram showing the configuration of a conventional ultrasonic diagnostic device that performs cross-mode sound velocity measurement, FIGS. 9 to 11 are diagrams for explaining its operation, and FIG. 12 is an example of the display of the conventional device. FIGS. 13 and 14 are diagrams for explaining the relationship between speckle reduction and the occurrence of time position measurement errors by conventional devices. 1... Probe, 13... Multiplexer, 14.
...Pulser, 15...Delay circuit for transmission, 16...II for reception! Extension circuit, 17...Display, 18...
・Calculation circuit, 19.27...Reception circuit, 20.28・
・・A/D converter, 21 ・・clock oscillator, 22・
...Memory, 23.. Processing circuit, 24.. Waveform analysis circuit, 25A.. System control means, 26.. Changeover switch, 29.. Marker generator, 30.. Digital scan. Converter, TI, ~T128...
・Ultrasonic vibration element. Applicant's Representative Patent Attorney Takehiko Suzue Figure 3 Figure 4 Figure 5 Figure 6 P Figure 7 Figure 97 Figure 11 Figure 12 T Figure 13

Claims (1)

[Claims] Using a probe configured by arranging multiple ultrasonic vibrating elements in parallel, a predetermined number of adjacent ultrasonic vibrating elements of this probe are grouped together, and a wave transmission path is created in a predetermined direction to the target region of the subject. A group of different ultrasonic beam transmitting and receiving groups, respectively, in order to transmit an ultrasonic beam by using a transmitter and receive the ultrasonic beam by a receiving path in a predetermined direction that intersects the transmitting path at the target site. Ultrasonic waves are transmitted and received using an ultrasonic vibrating element, the peak of the reflected wave from the target area is detected, and the time required from the transmission to the peak reception is measured to determine the propagation of the ultrasonic wave at the target area. In an ultrasonic diagnostic apparatus equipped with a sound speed measurement function that obtains speed information and uses it for diagnosis, at least switching between a sound speed measurement mode for measuring the sound speed and an ultrasound image observation mode for obtaining an ultrasonic B-mode image is performed, and the probe is A control means for controlling transmission and reception of ultrasonic waves so that each scan for collecting B-mode image formation data for one screen is intermixed with a scan for collecting sound velocity measurement data in the middle of the scan, and Marker generation means for displaying the sound wave transmission/reception path with a marker at a corresponding position on the ultrasound B-mode image displayed on the display device, and data based on the averaging of the ultrasound reception signals obtained for each same transmission/reception path during sound velocity measurement. An ultrasonic diagnostic apparatus comprising analysis means for determining the peak position of a received signal from a target region based on the information and obtaining the ultrasonic propagation time.