JPS60139238A - 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] [Field of Industrial Application] The present invention relates to an ultrasonic diagnostic apparatus, and particularly to a subject, which transmits and receives ultrasonic waves at a predetermined transmission edge repeating cycle to receive data from the body part to be examined. This article relates to an ultrasonic diagnostic device that has received a number of awards.

[Prior art]

In recent years, devices that transmit and receive ultrasonic waves to and from a subject and display the received signals as images on a CRT have become well-known. Since various internal information can be obtained, it is widely used, for example, for Doppler diagnosis of blood flow, the heart, etc., or for flaw detection of various objects.

An example of such an ultrasonic diagnostic apparatus is shown in FIG. Ultrasonic waves 100 are transmitted and received toward the region to be examined 14 .

In particular, the ultrasonic wave is transmitted by applying a transmission pulse from the transceiver 18 to the probe 10 at a predetermined transmission line repeating cycle, and this transmission pulse is applied from the probe 10. Ultrasonic waves are transmitted into the interior of the living body 12 every time the body 12 moves.

The ultrasonic wave 100 thus transmitted propagates inside the living body 12, is reflected by the test site 14, and returns to the probe 10 as an echo. Therefore, this echo is detected and CR
If displayed on 'l', the distribution of acoustic characteristics of body tissues can be displayed as an image.Also, since healthy tissue and tumor tissue have different acoustic characteristics, the image pattern displayed on CRT From this, the presence or absence of an abnormality existing inside the i-inspection site 14 and its location can be known.

Incidentally, in such an ultrasonic diagnostic apparatus, the transmission repetition period T of one ultrasonic wave is set to be longer than the time required for transmitting and receiving nine ultrasonic waves toward the region to be examined 14 . For this reason, the echo 110 from the test site 14 is received during the reception period associated with the transmission of each ultrasound, but the ultrasonic waves from the probe 10 are Some kind of echo source 1 whose transmission/reception time exceeds the ultrasound transmission repetition period T
6 exists, during the echo reception period for each ultrasound transmission, as shown in FIG. Delayed echoes 120 from echo source 16 will also be received.

However, in conventional ultrasonic diagnostic equipment, the received signal obtained in this way is processed as data from the examined part 14, so the received signal obtained does not include the true echo 110. Another drawback is that the delayed echo 120 is included as an error component, making it impossible to obtain an accurate diagnostic image of the region to be examined 14.

In particular, the mixing of such delayed echo components degrades the near-field image of the obtained diagnostic image, and the rate of deterioration increases as the transmission repetition period becomes shorter, so effective countermeasures are desired. was.

[Purpose of the invention]

The present invention was developed in view of the above-mentioned problems in the prior art, and its purpose is to transmit and receive ultrasonic waves to and from a subject at a predetermined transmission repetition rate, and to obtain data signals from the body part to be examined. , the ratio of the delayed echo component related to the previous ultrasound transmission to the true echo component from the area to be examined contained in the data signal is reduced, making it possible to make an accurate diagnosis. The purpose of the present invention is to provide a sonic diagnostic device.

[Structure of the Invention] [In order to achieve the above object, the device of the present invention transmits and receives ultrasonic waves toward a subject at a predetermined transmission line repeating cycle to obtain data signals from the inspected area. In a diagnostic device, a transmitter/receiver that transmits and receives ultrasonic waves at least at a transmission repetition period different from the previous one, and a delay that outputs the previous received signal obtained through the transmitter/receiver with a delay of the current transmission repetition period. circuit, and a synthesis circuit that synthesizes the current received signal obtained via the transceiver and the previous received signal obtained via the delay circuit to obtain a data signal from the test site. It is characterized by reducing the ratio of delayed echo components related to previous ultrasonic wave transmission to true echo components from the examined region included in the ultrasound examination.

〔Example〕

Preferred embodiments of the present invention will be described below based on the drawings.

Note that the same reference numerals are given to the members corresponding to those of the apparatus shown in FIG. 1, and the explanation thereof will be omitted.

(1) Principle of the present invention In giving a detailed explanation of the present invention, we will first start by looking at the data signal from the test site obtained by transmitting and receiving ultrasound waves, and then compare the data signals from previous ultrasound transmissions included in the data signal. The principle of the present invention for reducing such delayed echo components will be explained.

For example, as shown in FIG. 1, an echo source of some kind is located in the subject 12 at a position deeper than the test site 14, and the transmission and reception time of the ultrasound from the probe 10 is longer than the transmission repetition period of the ultrasound. Assume an acoustic model in which there are 16.

For such an acoustic model, the probe 10 transmits and receives ultrasonic waves 100 at a predetermined transmission repetition period to detect the area to be examined 14.
As described above, this data signal contains the true echo 110 #1 from the test region 14 and the delay from the echo source 16 related to the previous ultrasound transmission. Echo 120 is mixed in as an error component.

FIG. 3 shows a timing chart in the case where continuous ultrasonic wave transmission is performed at least at a repeating cycle of nine times different from the previous one. As is clear from the figure, when transmitting and receiving the ultrasonic waves 100 at different transmission repetition periods, the time required from the time when the ultrasonic waves 100 are transmitted until the true echo 110 is obtained from the test site 14 is Always constant, delayed echo 120 obtained from echo source 16
The time it takes for the signal to be received differs depending on the length of the transmission repetition period.

Therefore, as shown in FIG. 4, the received signal V obtained by transmitting ultrasonic waves 100 with a transmission repetition period of T, and the transmission edge p return period of T, which is different from T, By combining the received signal obtained by transmitting the ultrasonic wave 100 and the received signal, the delayed echo 120 from the echo source 16 is obtained.
The true echo 11 from the test area 14 remains the same.
It is possible to obtain a data signal v3 in which only the amplitude of 0 is amplified twice.

Therefore, the ultrasonic waves 100 are transmitted and received at least at a repetition period different from the previous one, and two sets of received signals V, , V, obtained one after another by such ultrasonic transmission and reception are synthesized. By doing so, it is possible to obtain a data signal Vs in which the ratio of the delayed echo component related to the previous ultrasound transmission to the true echo component from the region to be examined 14 is relatively reduced.

Therefore, the data signal V obtained in this way.

By extracting a signal of a certain level or higher from 9, it is possible to remove delayed echo components related to the previous ultrasonic wave transmission included in the data signal, and it is possible to remove the delayed echo component related to the previous ultrasonic wave transmission included in the data signal. Tested area 1 regardless
It becomes possible to obtain 4 accurate information.

(2) Embodiment of the apparatus of the present invention FIG. 5 shows a preferred embodiment of the ultrasonic diagnostic apparatus of the present invention to which the above-described principle is applied. is set toward a desired region to be examined 14 of the subject 12, and the ultrasonic wave 100 is transmitted and received at a predetermined transmission edge cycle to obtain a data signal from the region to be examined 14.

Here, the apparatus of the present invention is provided with a transceiver 18 that transmits successive ultrasonic waves at least at a transmission edge repetition period that is different from the previous one.

The transceiver 18 of the embodiment has two types of transmission edge return cycles T.
, and T, and these two types of transmission edge return periods T,
and Tv'' are repeated alternately, transmitting pulses to probe 1.
Apply to 0.

As a result, the ultrasonic wave 100 is transmitted from the probe 10 in synchronization with the application of the transmission pulse, and T and T! according to the timing chart shown in FIG. 02 types of transmission edge repetition periods are repeated 9 times alternately, and 7' (ultrasonic waves 100 are transmitted and received toward the subject 12.

The received signals V, , V, obtained by such transmission and reception of the ultrasonic wave 100 are converted into electrical signals by the probe 10, further amplified by a predetermined value by the transceiver 18, and then Wisdom ν
m defense O^ lICΔ姶n 絝りり f1 Yuzu pull.

The delay circuit 20 delays the thus-input received wave signal by the current transmission repetition period '1'1 or 17 minutes and inputs it to the synthesis circuit 22.

As a result, the current received signal ■1 is input from the transmitter/receiver 18 to the combining circuit 22, and at the same time, the delay circuit 20
The previous received signal V delayed by one transmission repetition period from
, will be input.

The synthesizing circuit 22 synthesizes both the current received signal V and the previous received signal V inputted in this manner, and outputs this as a data signal (2) from the test site 14.

The present invention has the above configuration, and its operation will be explained next.

According to the apparatus of the present invention, two types of transmission repetition periods T and T are alternately repeated from the probe 10 to the desired test region 14 of the subject 12, and the ultrasonic wave 100 is transmitted. will be held.

Therefore, the received signals 1 and Bv shown in FIG. 4 are alternately outputted from the subject 12 via the transceiver 18'li-.

Then, these received signals V or V! obtained via the transceiver 18 are received. are respectively input to the delay circuit 20 and the combining circuit 22, and the previous received signal delayed by one transmission line repeating period in the delay circuit 20 is input to the combining circuit 22.

Therefore, the combining circuit 22 outputs a data signal V in which the current received signal and the previous received signal are combined.

In this way, according to the apparatus of the present invention, even if some echo source 16 exists in the subject 12 at a position deeper than the subject part 14, the true echo component contained in the received signal is By significantly reducing the proportion of delayed echo components related to previous ultrasound transmissions, it becomes possible to obtain accurate data from the region to be examined 14.

In the above embodiments, two types of transmission repetition periods are alternately repeated to transmit and receive ultrasonic waves, but the device of the present invention is not limited to this. Any device that can transmit and receive ultrasonic waves may be used.

(3) A concrete example of the present invention A concrete example of the present invention will be described based on FIG.

In the apparatus of the embodiment, the transmitter/receiver 18 alternately repeats two types of transmission repetition periods, T and T, according to the timing chart shown in FIG. transmits and receives waves.

Here, if the angular frequency of the ultrasonic wave 100 to be transmitted and received is ωC (the angular frequency of the burst when performing burst transmission), the received signal input to the transceiver 18 has the following:
A time-varying ring of ωat is included. As a result,
In order to facilitate its handling, it is necessary to perform demodulation processing using a carrier wave of εja+ct.

For this purpose, the device of the embodiment transmits the received signal to the transmitter/receiver 18.
After amplifying the signal at a constant rate, the signal is input to the sine demodulation section 28a and the cosine demodulation section 28b of the complex demodulation circuit 26, respectively.

The sine demodulator 28a converts the input received signal into εj(t
After demodulating and detecting only the sine component using the carrier wave of Jct, the AD converter 30a performs digital signal processing and outputs the signal.

Further, the cosine rectangular chest 28b converts the input received signal into ε
After demodulating and detecting only the cosine component of the ja+ci carrier wave, the AD converter 30b performs full digital signal processing and outputs the signal.

In the device of the embodiment, there are two types of transmission line return cycles T,
and T are alternately repeated to transmit and receive the ultrasound, so that each time the ultrasound is transmitted, the phase of the transmitted ultrasound and the carrier wave used in each receiver section 28a, 28b are matched. It is necessary to do so.

Therefore, within the complex demodulation circuit 26, a carrier wave selection section 32 is provided.
This carrier wave selection section 32 is connected to the control circuit 2.
Based on four control signals, a carrier wave whose phase matches that of each transmitted ultrasonic wave is input to each demodulator 28a and 28b.

The complex demodulation circuit 26 of the embodiment has the configuration as described above. When vI is input, the sine component and cosine component of this received signal are demodulated and detected in the complex demodulation circuit 26, and the AI)
The converter 3 (la, 30b) outputs its sine component and cosine component.

Further, when the received signal ① is input from the transmitter/receiver 18, the complex demodulation circuit 26 similarly demodulates and detects the sine component and cosine component, and the sine component of the received signal vt is output from the AD converters 30a and 30b. and outputs the cosine component.

In this way, the sine and cosine components of the received signal vl or 2 outputted from the complex demodulation circuit 26 are input to the corresponding delay circuits 20a and 20b, respectively, and also to each adder 34a of the synthesis circuit 22.

34 and b, respectively.

Based on the control signal from the control circuit 24, the delay circuits 20a and 20b delay each demodulated and detected received signal by a time T corresponding to one transmission repetition period, or t'iTt, and then send it to the adder 3.
4a and 34b.

Therefore, the adder 34aK is connected to the adder 20 through the AD converter 30a.
The sine components of the previous received signal are input at the same time through the adder 34a, and the sine components of the previous and current received signals are added by the adder 34a and then sent to the multiplier 3.
6a. Further, another adder 34b K is AD
The cosine component of the current received signal and the cosine component of the previous received signal are input simultaneously through the converter 30b and the delay circuit 20b, and the cosine components of the current and previous received signals are input to the adder 34b. Then, the input δ is input to the multiplier 36b.

Here, in the apparatus of the present invention, two types of transmission line return cycles T and r are alternately repeated to transmit and receive ultrasonic waves, so the adder 34a receives the received signal
The sine components of the received signals vI and V are simultaneously input to the other adder 34b, and the cosine components of the received signals vI and V are simultaneously input to the other adder 34b.

Therefore, the adder 34a outputs the sine component of the data signal ■, which is a composite of the received signal ■1 and vt, and the adder 34b outputs the sine component of the data signal ■, which is the composite of the received signal ■1 and vt. The cosine component will be output.

The sine and cosine components of the data signal V outputted from each adder 34a, 34b are transferred to a multiplier 36a.
, 36b, respectively, and these multipliers 36
The outputs of a and 36b are added in an adder 38 and output as a signal representing 2 of the data signal 3.

In this way, the adder 38 outputs the squared value of the data from which the phase component that fluctuates depending on the predetermined time and distance is removed from the data signal . By calculating the square root via the square root calculation unit 40, it is possible to obtain a data signal V of the test region 14 from which phase components that vary with time and distance have been removed.

In this way, if the apparatus of this embodiment is used, even if some echo source exists in the subject 12 at a position deeper than the subject part 14, the previous ultrasound transmission included in the data signal The proportion of delayed echo components related to this can be relatively reduced, making it possible to obtain accurate data from the test site 14.

Furthermore, according to the device of this embodiment, the obtained data signal V,
Since phase components that vary with time and distance can be removed from the test site, accurate data can be obtained from the test site 14 even if the test site 14 is a dynamic object such as blood flow or the heart. becomes possible.

Therefore, the signals obtained by the device of this embodiment are transmitted to the display device 42, which includes a CRT or the like. By inputting this information, it becomes possible to display an accurate diagnostic image of the subject area 14 on the CRT.

〔Effect of the invention〕

As explained above, according to the present invention, when transmitting and receiving ultrasound waves toward a subject at a predetermined transmission line repeating cycle to obtain a data signal from the body part to be inspected, the It is possible to reduce the ratio of delayed echo components to true echo components from the site and obtain accurate data signals from the examined site.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an ultrasonic diagnostic apparatus, FIG. 2 is a timing chart of the ultrasound transmission line reversal period in a conventional ultrasonic diagnostic apparatus, and FIG. 3 is a diagram of the ultrasonic diagnostic apparatus of the present invention. FIG. 4 is a timing chart diagram illustrating the transmission repetition period; FIG. 4 is a waveform diagram of a received signal obtained by transmitting and receiving waves at the transmission repetition period shown in FIG. 3; FIG. 5 is a block diagram showing a preferred embodiment of the apparatus of the present invention, and FIG. 6 is a block diagram showing a specific embodiment of the apparatus of the present invention. 12... Subject 14... Test site 18... Transmitter/receiver 20... Delay circuit 22... Synthesis circuit 100... Ultrasound 110... True echo 190.1. :JIAb positive echo - = low - to vVl

Claims (2)

[Claims] (1) In an ultrasonic diagnostic device that transmits and receives ultrasound toward a subject at a predetermined transmission edge repetition period to obtain data signals from the examined area, ultrasonic waves are transmitted at a transmission edge repetition period that is at least different from the previous one. a transmitter/receiver that transmits and receives waves, a delay circuit that delays the previous received signal obtained through the transmitter/receiver by the current transmission repetition period time, and outputs the received signal obtained through the transmitter/receiver. a synthesizing circuit that synthesizes the previous received signal obtained through the signal and delay circuit to obtain a data signal from the tested part, An ultrasonic diagnostic apparatus characterized by reducing the proportion of delayed echo components related to previous ultrasonic wave transmission. (2) An ultrasonic diagnostic apparatus according to claim (1), wherein the transmitter/receiver alternately repeats two types of transmission repetition periods to transmit and receive ultrasound waves.