JPH03146039A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To perform an exact diagnosis on which individual difference of each body to be examined is reflected by detecting an echo level of a receiving signal and calculating delay data, based on a result of this detection. CONSTITUTION:At the time of executing an ultrasonic diagnosis, whether a patient (body to be examined) is changed or not, or whether an examination (diagnostic) part is changed or not is decided, and in the case it is changed, an echo level detecting operation is executed. Subsequently, a coefficient K (shows C/C' at the time when the speed of sound is varied from C to C') is varied by way of trial, and a value in which an echo level becomes the maximum value is obtained. Next, whether the echo level becomes maximum or not is decided and in the case it becomes the maximum value, the coefficient K is fixed. Thereafter, the echo level detecting operation is stopped. In such a way, the corresponding delay data is obtained at every body to be examined. In this regard, A and B denote an echo level detecting part for detecting an echo level, and a delay data generating part for calculating and generating delay data, based on the echo level, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to an ultrasonic diagnostic apparatus that obtains echo data by respectively transmitting and receiving ultrasonic waves to and from a subject based on delay data.

(Prior art) When obtaining echo data by transmitting and receiving ultrasonic waves to and from a subject in an ultrasound diagnostic device, delay data is set in advance and based on this delay data in order to focus on a desired depth position of the subject. Ultrasonic waves are transmitted and received using the same technology. In this case, for convenience, an average constant sound speed (1530 m/s) is used as the basis for calculating the delay data.

Here, the delay time actually added to the ultrasonic transmission/reception signal based on the delay data is as shown in FIG.
, and the delay time t at a position that is distance X from the beam center and has a path of 1□ to the focus point F.
When d is shown, it is shown as.

However, C: in-vivo sound speed; α: Bias value.

(Problem to be Solved by the Invention) However, in conventional ultrasonic diagnostic equipment, delay data should be calculated in response to different sound velocities depending on the subject to be diagnosed; Since a constant speed of sound is always used, there is a problem in that it is difficult to perform accurate diagnosis depending on each subject. In other words, when transmitting and receiving ultrasonic waves to focus inside the subject, there are individual differences in the focused position, and when composing images based on the obtained echo data, there are differences in image quality, so lesions may be overlooked. This may cause misdiagnosis.

The present invention has been made in response to the above-mentioned problems.
It is an object of the present invention to provide an ultrasonic diagnostic apparatus that can perform accurate diagnosis according to each subject.

[Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention provides an ultrasonic diagnostic apparatus that obtains echo data by transmitting and receiving ultrasound waves to and from a subject based on delayed data. The apparatus is characterized by comprising means for detecting an echo level of a received signal reflected from a subject, and means for calculating the delay data based on the detection result.

(Function) Detects the echo level of the received signal, calculates delay data based on this detection result, and transmits and receives ultrasonic waves. Further, if necessary, a gate means is provided to gate the received signal to set an arbitrary depth or range of the object and detect each corresponding echo level. This makes it possible to correct the speed of sound for each subject, making it possible to perform accurate diagnosis according to each subject.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the ultrasonic diagnostic apparatus of the present invention, where A is an echo level detection section that detects an echo level, and B is a block diagram that calculates and generates delay data based on the echo level. This is a delayed data generation section. The echo level detection unit A includes a gate circuit 1 to which an ultrasound video signal (echo signal) received by an ultrasound probe (not shown) and a gate signal are input, and A to which an output signal from the gate circuit 1 is input. The average value calculation circuit 3 includes an A/D converter 2 and an average value calculation circuit 3 to which an output signal from the A/D converter 2 is input. The gate circuit 1 is controlled by a gate signal and allows only echo signals corresponding to a given depth or range within the subject to pass through. This output signal is converted into a digital signal by an A/D converter 2, and then an average value of the echo signals is calculated by an average value calculation circuit 3.

Here, the above equation (1) is as follows: When the sound speed changes from C to C', 72 11 =K +α It is changed as follows.

However, K is a coefficient =C/C (2) (3). Therefore, each time the sound speed of the object changes, the coefficient also changes.

As a result, the average value of the echo signals calculated by the average value calculation circuit 3 also changes according to K.

The delayed data generation section B includes an average value change detection circuit 4 to which the output signal of the average value calculation circuit 3 is input, a coefficient selection circuit 5 to which the output signal from the detection circuit 4 is input, and a coefficient selection circuit 5 to which the output signal from the coefficient selection circuit 5 is input. It includes a multiplier 7 to which an output signal and an output signal from an R, AM (random access memory) 6 are input, and an adder 8 to which an output signal from this is input. The average value change detection circuit 4 changes the coefficient K on a trial basis by controlling the coefficient selection circuit 5, detects the change in the output signal of the average value calculation circuit 3 based on this, and determines the echo level. The maximum value K is determined and the coefficient selection circuit 5 is fixed (locked) at the maximum value K. As a result, K corresponding to the sound speed of each object, which was an unknown quantity, has been found. If the echo level is a value other than the maximum value, it means that it does not correspond to the sound speed of the subject.

The RAM 6 stores data corresponding to (1°-, jz)/c transferred in advance from the host CPU (not shown), and the multiplier 7 uses this data and the value of the locked coefficient. Take out and multiply both values. Adder 8 adds a bias value α to the output of multiplier 7. As a result, delay data corresponding to the sound speed of each subject can be obtained as shown in equation (2) above. The delay data obtained in this way is output to the transmitting section and the receiving section.

Next, the present invention will be described in detail with reference to the flowchart shown in FIG.

First, in performing ultrasonic diagnosis, as in step A, it is determined whether the patient (subject) or the area to be examined (diagnosed) has changed.

If it has changed, the flow advances to step B, where an echo level detection operation is performed. If there is no change, the flow jumps to END. Next, in step C, the coefficient K is changed on a trial basis to find a value that maximizes the echo level. Subsequently, in step D, it is determined whether the echo level has reached the maximum. When the maximum value is reached, the flow advances to step E where the coefficient K is fixed. If the maximum value is not reached, the flow returns to step C and the cycle is repeated until the maximum value is reached. The flow then proceeds to step F, where the echo level detection operation is stopped. As a result, delay data corresponding to each subject can be obtained.

In this way, according to this embodiment, delay data corresponding to the sound speed of each subject can be obtained, so it is possible to perform ultrasonic diagnosis that reflects the individual differences of each subject. Accurate diagnosis can be made. That is, when focusing inside each subject, the optimum focus is applied to a position suitable for each object, so there is no difference in image quality during image reconstruction.

This prevents lesions from being overlooked and misdiagnoses.

In the embodiment shown in FIG. 1, a ROM may be used in place of the RAM 6, and a multiplication accumulator may be used in place of the multiplier 7 and adder 8. Furthermore, the A/D converter 2 may be provided after the average value calculation circuit 3.

Figure 3 shows a second embodiment of the present invention, in which the speed of sound is reduced to 1.
A delay data generating section B is provided which can calculate delay data consisting of a sound velocity data supply section 9 and a delay data calculation section 10 as two parameters. Here, the sound speed data itself is changed according to the echo level, so that the delay time td is generated at the optimum sound speed. The delay data calculated at the optimum sound speed can be stored in the RAM. The second embodiment can also provide the same effects as the first embodiment.

[Effects of the Invention] As described above, according to the present invention, the echo level of the received signal is detected and the delay data is calculated based on this detection result, so that the individual differences of each subject are reflected. Diagnosis can be made and accurate diagnosis can be made.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a first embodiment of the ultrasonic diagnostic apparatus of the present invention, Fig. 2 is a flowchart explaining the operation of this embodiment, and Fig. 3 shows a second embodiment of the present invention. The block diagram, FIG. 4, is a detailed explanatory diagram of the present invention. A...Echo level detection section, B...Delay data generation section, 1...Gate circuit, 3...Average value calculation circuit, 4...Average value change detection circuit, 5...Coefficient Selection circuit, 6...RAM. 9... Sonic speed data supply unit, 10... Delay data calculation unit.

Claims (2)

[Claims] (1) In an ultrasonic diagnostic apparatus that obtains echo data by transmitting and receiving ultrasonic waves to and from a subject based on delay data, there is a means for detecting the echo level of a received signal reflected from the subject, and a means for detecting the echo level of a received signal reflected from the subject, and An ultrasonic diagnostic apparatus comprising: means for calculating the delay data based on the delay data. (2) The ultrasonic diagnostic apparatus according to claim 1, further comprising gate means for detecting an echo level corresponding to an arbitrary depth or range of the subject.