JPS6351845A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic diagnostic apparatus that can obtain blood flow information at a plurality of different points in the depth direction of ultrasonic scanning.

Conventionally, methods for obtaining blood flow information at a plurality of different points in the depth direction of the ultrasound scanning direction include (1) D, W,
Baker, “Pulsed DopplerBl
ood Flow Sensing', IE
EETransactions 5onics and
Ultrasonics.

Vol, 5U-17, P170-185.1970 (2
) M. Brandestini, “Topo
rlow-ADigital Full Range
Dopplcr VelocityMeter”
, IEE Transactions 5
onicsand Ultrasonics, Vol.
, 5u-25, P 287-293, Sept
ember, 1973. There is.

Baker's method has multiple channels for each depth direction, and each channel is equipped with its own Doppler detection circuit to collect blood flow information along the travel line. It is something to do. In the Brandestini method, a received ultrasonic signal is first phase-detected and converted into a phase-detected digital signal. Next, convert this digital signal into MT I
(Moving Target Indjcator
) to remove relatively low Doppler signals due to fixed reflections.

After that, Doppler signals of multiple channels are calculated in the depth direction using a digital zero crossing counter.

Even with these Baker's methods, B randest
Even with the ini method, the obtained Doppler signal is displayed as a curve distorted depending on the strength of the Doppler signal.

For this reason, there is a problem in that it is difficult to instantaneously perceive the speed and direction of blood flow. Another problem is that it is not suitable for display using two-dimensional Doppler scanning.

For this reason, as shown in JP-A-51-136443, for example, if there is no Doppler shift, the color is set to yellow or yellow-green, if the blood flow is approaching, it is set to redder, and if it is moving away, it is set to the front. Some display colors are shifted to . However, with this conventional method, when the speed of blood flow is constant, it is possible to form an extremely easy-to-read screen, but when the speed of blood flow changes, the colors mix together, making the screen difficult to see. In addition, if the temporal speed change is not constant and each part has a large deviation from the overall movement, complex color mixing will occur in each part of the image, especially in the positive and negative directions. A display unit with a mixture of both has the disadvantage that it becomes almost impossible to decipher the screen.

The present invention was made in consideration of these problems, and displays blood flow information along the ultrasound scanning direction by modulating the brightness according to the blood flow velocity and changing the color according to the direction of the blood flow. By doing so, it is an object of the present invention to provide an ultrasonic diagnostic device that can be sensed instantaneously and can also be applied to display two-dimensional Doppler scanning.

In order to achieve this object, the present invention includes a plurality of electroacoustic transducers that transmit and receive ultrasonic waves toward a subject, and a plurality of electroacoustic transducers that transmit ultrasonic waves from the electroacoustic transducer elements. A pulse generator that energizes at a predetermined rate cycle, a receiving circuit that amplifies the ultrasonic signal received by the electroacoustic transducer, a scanning circuit that changes the direction of transmission and reception of the ultrasonic wave, and the receiving circuit. an A/D converter that sequentially samples the ultrasonic signal supplied from the ultrasonic signal in the scanning depth direction and converts it into a digital signal; a memory unit that stores the output of the A/D converter for a plurality of rate cycles; A Doppler detection circuit that reads out ultrasound signals stored in the memory unit at the same depth but with different rate cycles and determines the blood flow velocity and blood flow direction at each depth; The apparatus is characterized by comprising a display section that converts the brightness according to the blood flow velocity and displays the display in a different color depending on the direction of the blood flow.

Before explaining the present invention, first, an example of blood flow observation at only one location will be explained with reference to the drawings.

(The following is a blank space.) Figure 1 is a schematic configuration diagram. The reference oscillator 1 is composed of, for example, a crystal oscillator, and has a frequency of 5 MHz (2f
D) A signal having highly stable frequency characteristics is oscillated and output. This oscillation output is input to a frequency divider 2 consisting of a flip-flop on the negative side and divided by 2, and on the other side is inverted by an inverter circuit 3, and then input to a frequency divider 4 and divided into 2.
The frequency is divided. Therefore, each output of the frequency dividers 2 and 4 becomes a signal with a frequency of 2.5 MHz and a phase difference of π/2. The output signal of the frequency divider 2 is supplied to the frequency divider 5, and the frequency is divided by N (N is an integer, for example, 500).
The frequency signal is output as a rate frequency signal of 5 kHz. This signal is supplied to the control circuit 6 and also to delay circuits 7a, 7b, . . . , 7n, respectively. The delay time of these delay circuits 7a, 7b, . and each delay circuit 7a, 7b.

. . , 7n are sent to the pulsers 8a, 8b.

−6= . . , 8n, respectively, and the same pulsers 8a and 8b.

. . . , 8n, respectively.

9b, . . . , 9n are respectively energized to transmit ultrasonic signals. Note that these vibrators 9a, 9b,
, 9n are arranged, for example, in a straight line to form an array structure, forming an ultrasonic probe, that is, an electroacoustic transducer.

On the other hand, the signal reflected at the in-vivo reflection site of the transmitted ultrasonic wave is transmitted to the ultrasonic transducer 9a.

The waves are received at 9b, . . . , 9n, respectively. Then, the received signals are amplified via preamplifiers 10a, 10b, ~Ion, respectively, and then delayed and outputted after being delayed by delay circuits 118.11b, ~lln whose delay times are set by the control circuit 6. . In addition, the delay circuits 11a, ll
Each set delay time of b, ~, 11n is the same as that of the previous delay circuit 7a.
, 7b.

. . . , 7n, respectively. Thus, each delay circuit 11a, llb.

. This output signal is detected via a detector 13 and supplied to a display device 14 as a tomographic information signal. Further, the output signals of the addition and synthesis circuit 12 are supplied to mixers (MIX) 15 and 16, respectively. These mixers 15 and 16 each input the output signals of the frequency dividers 2 and 4, and the output signal, that is, the frequency f that is the reference for the rate frequency.

(2.5 MHz) signal and the received signal are mixed. Each mixed output of mixers 15 and 16 is filtered by filter 17.
18 and then input to a phase comparator 19, where the phases of the signals are discriminated. For example, when the phase discrimination result is positive, it indicates that the blood flow is flowing toward the propagation direction of the ultrasonic signal, and when the value is negative, it indicates that the blood flow is flowing away from the ultrasonic signal. This information is input to the display device 14 and displayed.

Further, the output signal of the filter 17 is input to a range gate circuit 20. The gate of the circuit 2o is opened by an MM 22 which is turned ON for a predetermined period by the output of a monostable multivibrator (hereinafter abbreviated as MM) 21 which operates in response to the rate signal (output of the frequency divider 5). be.

In other words, the reflected ultrasound signals that are received continuously in time series are:
The time of wave reception is proportional to the depth of the area to be inspected.

Therefore, by setting an appropriate elapsed time in MM21 and operating MM22 at the output timing to obtain a signal with a predetermined time width, the range gate circuit 20 can extract only the diagnostic information signal of the desired observation site. become. The output of this range gate circuit 20 is passed through a band pass filter (BPF) 23.
By using this method, it is possible to obtain Doppler shifted frequency component information, that is, a signal proportional to the blood flow velocity.

FIG. 2 is a waveform diagram of each part showing the operation of the device shown in FIG. Frequency 5k obtained by
Hz rate frequency signal. Pulsa 8a, 8b,
. . , 3n are synchronized at each rising edge of the signals 112 and are driven under delay time control. Therefore, the vibrator 9
a, 9b, ~.

As shown in FIG. 2(b), an ultrasonic signal is transmitted from 9n (probe) at a rate period of 200 μs. The center frequency (fl) of the transmitted ultrasonic pulse is approximately 2.5MHz
It is. When such a transmitted ultrasonic signal is reflected and received by various parts within the living body, the received signal becomes as shown in FIG. 2(c). This received signal (output of the addition/synthesis circuit 12) is output as a signal as shown in FIG. ing.

The reflected wave from a fixed reflector has a waveform as shown in Figure 3 (a), and its frequency spectrum is shown in Figure 3 (b).
It has a wide band frequency component including the center frequency fl (approximately 2.5 MHz). In this state, it is not possible to detect a very slight Doppler shift of about 1 kHz. However, as in an embodiment of the present invention, a very accurate λ (exactly 5 kH divided from a dedicated oscillator)
When the pulse shown in Fig. 3 (a) is repeated at a rate of 10 - wave number of z, the frequency spectrum becomes as shown in Fig. 3 (C), and the envelope line is equal to the spectrum of one pulse, and only frequencies that are integral multiples of 5 kHz are generated. The line spectrum becomes Therefore, the reflected wave from the fixed reflector obtained by the circuit of FIG. 1 has a spectrum as shown in FIG. 3(C). There is no problem because the pulsers and amplifiers have delay times, and the delay time caused by the delay circuit varies depending on the scanning direction or is always equal in the constant scanning direction.

FIG. 3(d) is an enlarged view of the horizontal axis, where the solid line is the reflected wave spectrum from a fixed reflector, while the chain line is the spectrum of the reflected wave from a moving object, which has undergone a Doppler shift of Δf. Therefore, by mixing this signal with the output of the reference oscillator (frequency fO) using a mixer and extracting the difference frequency, the Doppler deviation frequency can be detected.

If the line spectrum of the rate frequency signal is the reference wave signal f
If it is unstable with respect to O, the fluctuation of the rate frequency signal with respect to the reference wave signal itself is regarded as the Doppler shift frequency, and it becomes difficult to obtain an accurate Doppler signal.

On the other hand, the mixer 15 mixes the received signal (not shown in FIG. 2(c) in 1-) and the reference signal with a frequency of 2.5 MHz, which has been divided by 2, as shown in FIG. 2(e). I am getting mixed output. This signal is filtered through a filter 17 and the second
It is converted as shown in Figure (f). FIG. 2(g) shows the sampling timing of the range gate circuit 20. By sequentially sampling the filter output shown in FIG. 2(f) at the same timing, the Doppler polarization of the reflected ultrasound at one observation site is determined. The phase components are obtained as shown in the figure (h). FIG. 2(i) shows the signal shown in FIG. 2(h) compressed on the time axis.
A Doppler signal as shown in j) is obtained. Thus, the observation information regarding the tomographic image as shown in FIG. 2(d) is obtained as the output of the detector 13, and the second observation information is obtained as the output of the filter 23.
Doppler signal observation information regarding blood flow velocity as shown in Figure (j) can be obtained at the same time.

Incidentally, although the control circuit 6 described in, for example, Japanese Patent Application No. 52-28016 is generally used, the following configuration is suitable for the present apparatus.

That is, the control circuit 6 is equipped with a ROM (read only memory), and each address of the ROM is made to correspond to the scanning direction of the ultrasonic waves. Each address includes the delay circuits 7a, 7b, which are necessary for transmitting and receiving ultrasonic waves in the scanning direction.
~, 7n.

Delay time setting information for (lla, llb, . . . , 1ln) is stored. Therefore, by selecting and specifying the address of the ROM that corresponds to the specified scanning direction, the ultrasonic signal will be transmitted in the ``-2 specified scanning direction, reflected by the reflecting object, and received in the above direction. Become. Now, as shown in FIG. 4, the scanning directions of the ultrasonic signals transmitted and received by the probe 26 are 1, 2, . ~． To,
~.

64. It is assumed that information on a position P in direction k is observed from a Doppler signal. In this case, the scanning direction specified by the ROM is rl, 2°k, 3. By specifying the scanning direction k for every root pulse as shown in ``~'' and sequentially specifying the scanning direction 1 for other rate pulse timings, Doppler signals and M-mode signals can be obtained when scanning in the direction. , B mode, that is, real-time tomographic images can be obtained by specifying other directions. In other words,
Real-time tomographic images and blood flow velocity information can be observed simultaneously. Also, at this time, the effective rate frequency of the B-mode and Doppler signals is 1/2 of the frequency shown above, that is, 2.5 kHz.

Note that if the display output is configured to be luminance-modulated at the sampling timing by the range gate circuit 20, the blood flow observation position can be displayed accurately.

Now, the ultrasonic signals used for the tomographic image and blood flow observation may both be single pulses, but for example, FIG.
) For blood flow observation, a single pulse with a higher amplitude level as shown in (b) of the same figure, or a pulse with a higher number of waves as shown in (e) of the same figure, is used for blood flow observation. It is more convenient to use a burst type. By using such an ultrasonic signal, it is possible to improve the S/N ratio in blood flow observation without causing a decrease in distance resolution. Therefore, the ultrasonic probe 26 shown in FIG. 5(d)
By alternately transmitting single-pulse ultrasound waves and burst waves according to a predetermined rate from Both can be obtained as signals with high distance resolution and good S/N ratio.

The following explanation describes an embodiment of the present invention in which blood flow observation was performed at only one location on one scanning line, but blood flow observation at multiple locations can be performed simultaneously on one scanning line. do. Figure 6 shows an example of this, in which a plurality of MM21, 22, range gate circuit (RG) 20°BPF23, etc., which constitute the latter stage of the frequency divider 5, are arranged in parallel to form a multi-channel configuration. be. That is, frequency divider 5
The output (rate signal) of MM2 is passed through a gate circuit (G) 31 gate-controlled by a flip-flop 30.
1a, 21b, ~, 21n = 15-. The flip-flop 30 operates inverted by inputting a rate signal O (frequency 2N).
The gate circuit 31 is opened only at the timing of transmitting and receiving ultrasonic waves in the scanning direction described above. Therefore, when transmitting and receiving ultrasonic waves in the scanning direction, that is, when observing blood flow, the output of the frequency divider 5 is M
M21a, 21b, ~.

21n. These MM21a, 21b.

, 2In have pulse time widths set as shown in FIGS. 7(a), (c), and (e), respectively. And M
M22a, 22b, ~, 22n are MM21a, 21b
, ~, operates at the falling edge of the output signal of 21n,
For example, Fig. 7 (b) and (d) with a pulse time width of 4 μs.
, outputs a signal with the timing shown in (f). Now, the MM21a, 21b, ~, 21n are 33
The time corresponding to the depth from the surface of the probe 26 is, for example, 26 μs, 30 μs, 34 μs, etc.

Assuming that the time is set sequentially to 160 μs, the received signal input from the 1-ilter 17 to the range gate circuits 20a, 20=16-b, ~, 20n is as shown in FIG. 7(g).
The samples will be sequentially sampled in accordance with the depths shown in . In other words, the depth from the surface of the probe 26 is 20 mm,
Reflection information will be extracted at three reporting intervals: 23 mm, 26 mm, ~, 120 mm.

These reflection information are transmitted to the BPFs 23a, 23b, . . .

23n and then a zero crossing detector (ZC) 32a.

32b to 32n, and the zero crossing timing of the output level is detected. These are ZC32a, 32
32n calculates the Doppler deviation frequency from the zero-crossing timing and performs, for example, frequency-voltage conversion (F/V conversion) to obtain an amplitude signal proportional to the blood flow velocity and supplies it to the recording device 33. In addition, zero crossing detectors 32a, 32b, ~, 32
For example, n may be any value that counts the number of zero crossings of a signal within a predetermined period of time. A frequency analyzer may also be used instead.

Thus, Doppler deviation information, that is, blood flow information at multiple locations can be obtained simultaneously from one piece of ultrasound scanning information.

FIG. 8 shows the configuration of another embodiment in which Doppler deviation information at a plurality of locations is obtained simultaneously from one piece of ultrasonic scanning information. A flip-flop (FF) 35 functions similarly to the flip-flop 30 described above, and is supplied to the gate circuit 36 together with the output of the frequency divider 5. The gate circuit 36 outputs a rate signal with a frequency of 2.5 kHz (2N) based on the 5 kHz signal from the frequency divider 5 and the output of the FF 35. This rate signal is applied as a scan control signal to a random access memory (RAM) 37 having an address structure as shown in FIG. That is, the RAM 37 stores, for example, a 64×64 address “1°IJ rl, 2J~rl
, 64J r2. It has IJ~r64,64J, and the output of the filter 17 is A, /
It is digitized and written via a D converter 38. Incidentally, information writing into the RAM 37 and reading which will be described later are controlled by a 400 kHz clock signal output from a clock oscillator 39. Therefore, the ultrasound information obtained by -scanning is sequentially converted into digital data at addresses rl, IJrl, 2J~
rl and 64J.

The next obtained ultrasound-scanning information is row-changed under the control of the gate circuit 36, and address r2. I
J r2,2J r2,3J~Written in "2°64". Similarly, the 64th one-scan information is at address r64. Written to IJ r64,2J to r64,64J. In this case, the time required to write one scan information to the memory address of the - row is 400k at the clock frequency.
Hz and the address is 64, so it is approximately 160
It becomes μs. This is - the depth of the observation site by scanning O ~ 1
Corresponds to 2cm culm size. Further, this Doppler scanning and B-mode scanning for tomographic image observation are performed alternately, and the rate interval between each is 400 μs. Therefore, all information is written to all addresses (64×64) in the RAM 37 in 25.0 ms. It goes without saying that each address position corresponds to the depth of the observed region.

On the other hand, the information written as described above is now sequentially addressed column by column and read out. This readout is performed using a 400 kHz clock signal as described above. That is, first, address rl, IJ r2.
IJ r3. The information from IJ to "64°1" is read in the column direction, and then the address rl, 2J r2, 2J
Information of r3, 2J to r64, 2J is read. Therefore, the same depth of the information series read out over a row of the above addresses, that is, the time course of the signal subjected to Doppler deviation at the same observation site, and therefore, as mentioned above, the output is restored via the D/A converter 40, smoothed via the filter 41, and zero-crossing detection is performed at the ZC 42. The detection result becomes a Doppler signal at the observation position. In this way, Doppler signals at each column of memory addresses, in other words at a plurality of observation positions, are obtained. At this time, if the column readout cycle is set to 160μS,
The Doppler signal at one observation position is read out every 160 μs×64, that is, every 10.24 ms.

The Doppler signal obtained in this way is sent to the A/D converter 43.
The data is digitized via the computer and input into the memory 44. This memory 44 receives a signal obtained by dividing the 400kHz clock signal by 64 via a frequency divider 45, that is, 6.2.
The above-mentioned manually generated Doppler signal is written as a 5kHz signal. Thereafter, the Doppler signal written in the memory 44 is read out at a speed of 400 kHz, converted to an analog signal (amplitude signal) via the D/A converter 46, and then supplied to the display device 47 to display the brightness. It is modulated and displayed. This display device 47 receives the rate signal from the frequency divider 5 and performs sweep scanning.
The brightness-modulated signal will be displayed corresponding to the observation site. That is, the magnitude of the blood flow velocity at each observation site is displayed as brightness information that is luminance-modulated. still,
When displaying the direction of blood flow, for example, a color display cathode ray tube is used to display the positive direction in red and the negative direction in blue. Further, the output of the RAM 37 is subjected to fast Fourier transform to perform frequency analysis, and the analysis result is written directly into the memory 44.

Furthermore, the display device 47 may of course display the tomographic image obtained by B-mode scanning together with the information on the blood flow velocity. It goes without saying that the scanning direction for Doppler observation may be variably set.

By the way, by synchronizing two consecutive Doppler observations with an electrocardiograph or the like, it is possible to perform over the entire ultrasound diagnostic region. In this way, for example, a tomographic image of the heart can be obtained by B-mode scanning, information on the circulation of blood flowing in the heart can be obtained by Doppler scanning, and the state of change can be displayed moment by moment.

The explanation will be given below with reference to FIG.

The RAM 37 is similar to that shown in FIG. 8, and its output is input to a digital zero crossing meter (DZC) 51 to obtain a Doppler signal.

This DZC 51 calculates the output of the RAM 37, that is, the number of zero crossings of the above-mentioned sampling value, and calculates a Doppler signal from the result. This Dobra signal is written at a frequency of 400kHz by the clock oscillator 52,
It is supplied to the RAM 53 which is read-out controlled, and the RAM
53 addresses are sequentially written. Also RAM5
The writing timing of No. 3 is established in synchronization with, for example, the R wave of an electrocardiograph (ECG) 55 extracted via the waveform shaping circuit 54.

For example, as shown in FIG.
This is used to configure the address structure of When the R wave of the first heartbeat is obtained by the ECG 55, the RAM 53 stores the Doppler signal output from the DZC 51 in synchronization with the R wave at address rl, 1.
IJ rl, 1. 2'' to rl, 1,64J sequentially. That is, the address rl of the RAM 53, 1. I.J.
is the address r1. of the RAM 37. IJ r2. I
J r3. The Doppler signal obtained from the information of IJ~r64.14 is written, and the addresses rl, 1.
24 is the address rl of RAM37, 2J r2,2
The Doppler signal obtained from the information of Jr3, 2J to r64, 2J is written. And for the next rate, RAM3
The Doppler signal obtained from the information read from R
AM53 address r2,2. IJr2,2,2J
r2, 2.3'' to r2, 2, 64J. Furthermore, at the next rate, address r3,3 of RAM53
．． IJ r3.3.2Jr3,3,3J~r3,3,
64J. When a second heartbeat is detected by the ECG 55, address II is then detected.
, 2°IJ rl, 2.2J~rl, starting from 2,64J, addresses r2, 3 . IJ r2,3,2J
~r2,3,64J, and r3. 4. I.J.
r3゜4.2''~r3,4,64J, and further address r
64,1. IJ r64.1,2J~r64,1°6
4'' and Doppler signals are sequentially written.

In this way, when all Doppler signals have been written to the addresses (64x64x64) of the RAM 53 in synchronization with 64 heartbeats, from address "1°1.1" to rl,
In the first region reaching 64 and 64J, a heartbeat is obtained, and information on the blood flow velocity indicated by the Doppler signal in the extra concave region in the first state is stored. Also address r2,1
．． The second region from IJ to r2, 64, and 64J stores information on blood flow velocity in all diagnostic regions in the second state based on the manual timing of heartbeat.

In the same way, each memory area of the RAM 53 stores information on the blood flow velocity of all diagnostic areas according to the passage of time.

Therefore, if the memory area of the RAM 53 is designated according to the state of the tomographic image obtained by B-mode scanning, and the Doppler signal stored in the same area is read out and the image is displayed,
The image becomes a blood flow velocity information image of the entire diagnostic region corresponding to the displayed tomographic image.

In addition, when displaying the above six images on the display device 56,
For example, a tomographic image is displayed in white by modulating the brightness, and blood velocities in the positive and negative directions are displayed in red and blue by modulating the brightness. In this way, for example, it is possible to easily grasp changes in blood flow at the same time as the movement of the heart, which is particularly effective in diagnostic medicine of the circulatory system.

Note that the heart does not necessarily move in exactly the same way every heartbeat.

Therefore, by repeating the dry mountain process a plurality of times and calculating the average, sufficiently accurate information can be obtained. Furthermore, if a Doppler signal is written to one row address of the RAM 53, for example, from rl,1゜1'' to rl,1,64j under the above conditions, the time required is 400μ5.
X64-25.8ms. Therefore, the Doppler signals in each area of the RAM 53 are signals after a period of 25.8 ms has passed. In other words, the information (Doppler signal) stored in the first area is, for example, at time zero, the information in the second area is 25.6 ms later, and the information in the third area is 51.2 ms later.
It is said to be after TIl. Therefore, the distribution state of blood flow velocity is 25. It can be read out and displayed as a change for each Bms. Therefore, the signal reading clock frequency from the RAM 53 only needs to be 160 kHz or higher.
For example, if a clock signal of 200 kHz or 400 kHz is used, reading can be performed with sufficient margin.

As described above, according to the present invention, blood flow information is instantaneously modulated in accordance with the blood flow velocity and the display color is changed in accordance with the direction of blood flow to display Doppler signals. Perceivable. In addition, even when the blood flow speed changes, the colors do not get mixed up and the blood flow speed is easy to read. Moreover, in the present invention, since the Doppler detection signal is temporarily stored in the RAM 37, calculation of the blood flow velocity by FFT or the like can be performed without depending on the rate pulse of the ultrasound. Therefore, it is possible to provide an ultrasonic diagnostic apparatus that can quickly determine the blood flow velocity of each cartwheel at a large number of locations.

Note that the present invention is not limited to the examples.

For example, the rate frequency and reference oscillation frequency of the ultrasonic signal, as well as the writing and reading frequencies for the memory, etc. may be determined according to the specifications. Further, the address structure of the memory and the Doppler signal detection means may be determined as appropriate. Further, in the above embodiments, a sector scan system was described, but a linear scan system may of course be used. Furthermore, in the case of a simple device, blood flow velocity information for the entire diagnostic region may be obtained only two-dimensionally. In short, the invention can be modified and implemented without departing from the gist of the invention.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram showing an example of Doppler observation at one location.
Figure 2 is a signal waveform diagram of each part showing the operation of the device shown in Figure 1, Figure 3 is a diagram showing a repetitive pulse signal, and Figure 4 is a diagram showing the relationship between the probe and the scanning direction of the ultrasound signal. 5 is a diagram showing switching between B-mode scanning and Doppler scanning and ultrasound signal waveforms, FIG. 6 is a schematic configuration diagram of main parts showing another embodiment of the present invention, and FIG. 7 is a diagram showing the ultrasound signal waveform. FIG. 8 is a schematic block diagram of main parts showing another embodiment of the present invention; FIG. 9 is a diagram of the address block diagram of the RAM shown in FIG. 8; FIG. 11 is a schematic block diagram of the main parts showing still another embodiment of the present invention, and FIG. 11 is a diagram of the address structure of the RAM shown in FIG. 10. DESCRIPTION OF SYMBOLS 1... Reference oscillator, 2.4... Frequency divider (reference frequency), 5... Frequency divider, 7a, 7b, ~, 7n... Delay circuit, 8a, 8b, ~, 8 n-=pulsa, 9a, 9b, ~. 9n... Ultrasonic transducer, lla, llb, ~, 11
n...delay circuit, 12...addition synthesizer, 13...
Detector, 14...Display device, 15.16...Mixer, 17°18...Filter, 19...Phase comparator,
20... Range gate circuit, 21.22... Monostable multivibrator, 23... Filter (BPF)
, 26... probe (electroacoustic conversion element), 30...
Flip-flop, 31--gate circuit, 32a, 3
2b, ~. 32n... Zero crossing detector, 36... Gate circuit, 3
7...RAM, 39...clock oscillator, 42...
- Zero crossing detector, 44... Memory, 51... Digital zero crossing detector, 53... RAM, 54... Waveform shaping circuit, 55... Electrocardiograph (ECG). Applicant's agent Patent attorney Ken Ken Kondo Butsuma (procedural amendment) 1. Indication of the case Japanese Patent Application No. 114507/1983 2 Name of the invention Ultrasonic Diagnostic Device 3 Relationship with the Ministry case to be amended Special applicant (307) Toshiba Corporation 4, Agent Address: 105 Shibaura, Minato-ku, Tokyo 1] Figure 11 of No. 1 has been corrected from the attached sheet.

Claims (1)

[Claims] A plurality of electroacoustic transducers that transmit and receive ultrasonic waves toward a subject, and a pulse generator that energizes the electroacoustic transducers at a predetermined rate cycle in order to transmit the ultrasonic waves from the electroacoustic transducer elements. a receiving circuit that amplifies the ultrasonic signal received by the electroacoustic transducer; a scanning circuit that varies the direction of transmission and reception of the ultrasonic wave; and a scanning circuit that adjusts the scanning depth of the ultrasonic signal supplied from the receiving circuit. An A/D converter that sequentially samples in the horizontal direction and converts it into a digital signal, and
A memory section that stores the output of the /D converter for a plurality of rate cycles, and an ultrasonic signal stored in this memory section at the same depth but with different rate cycles is read out, and the blood flow velocity and the blood flow velocity at each depth are read out. The present invention includes a Doppler detection circuit that determines the blood flow direction, and a display unit that converts the brightness according to the blood flow velocity determined by the Doppler detection circuit, and displays the display in a different color depending on the blood flow direction. Features of ultrasonic diagnostic equipment.