JP2909757B2 - Ultrasound diagnostic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus, and more particularly, to an improvement in non-uniformity of sound ray density in an ultrasonic diagnostic apparatus that simultaneously receives a plurality of sound rays. About.

[Prior Art] FIG. 4 is a block diagram of a conventional ultrasonic diagnostic apparatus 51 capable of simultaneously receiving two sound rays.

In the ultrasonic diagnostic apparatus 51, a transmission sound ray SL perpendicular to the probe 2 is formed by the scan controller 59, the transmission delay circuit 53, the driver 4, and the probe 2 as shown by a broken line in FIG. Each time it changes, the transmission sound ray SL is moved as shown by the broken line in FIG.

By the common delay circuits 55 and 56, the individual delay circuits 57a and 57b having wedge-shaped characteristics, and the individual delay circuits 62a and 62b, as shown in FIG. Two different reception sound rays RL are formed simultaneously. The common delay circuit 56 is a variable delay circuit, and can track the depth by the scan controller 59 to change the focus distance.

The received data of the two received sound rays RL obtained at the same time are processed by the signal processing circuits 58a and 58b, respectively, and sent to the DSC 60.

DSC60 forms an image with the obtained reception data,
Display a tomographic image on RT11.

[Problems to be Solved by the Invention] In the conventional ultrasonic diagnostic apparatus 51, the total sound ray TL obtained by integrating the transmission sound ray SL and the reception sound ray RL is, as shown in FIG. And the receiving sound ray RL, and has directivity different from the transmitting sound ray SL by an angle θ / 2.

For this reason, considering the entire tomographic image, as shown in FIG. 6, there is a problem that the density of the total sound ray TL becomes non-uniform and a uniform resolution cannot be obtained.

Also, if the non-uniformity of the total sound ray density is not taken into account, the image will be distorted, but there is a problem that the signal processing taking this into account becomes very complicated.

Accordingly, an object of the present invention is to provide an ultrasonic diagnostic apparatus capable of simultaneously receiving a plurality of sound rays with a uniform sound ray density.

[Means for Solving the Problems] An ultrasonic diagnostic apparatus according to the present invention uses a common delay circuit and individual delay circuits having wedge-shaped characteristics to transmit a plurality of reception sound rays slightly different from ultrasonic transmission sound rays. In an ultrasonic diagnostic apparatus that performs simultaneous multiple sound ray reception, the depth of the wedge-shaped characteristic of each individual delay circuit is made smaller as it goes deeper into the body, and the position is slightly parallel to the transmitted sound ray of the ultrasonic wave. The configuration is characterized by including a delay circuit control means for forming different reception sound rays.

[Operation] In the ultrasonic diagnostic apparatus of the present invention, the delay circuit control means controls the depth of the wedge-shaped characteristic of each individual delay circuit such that the depth decreases as the depth of the living body increases.

Therefore, the steering angle of the reception sound ray is large in the shallow part of the living body and small in the deep part of the living body, so that the reception sound ray can be formed substantially parallel to the transmission sound ray.

Therefore, the total sound rays become substantially parallel to each other, and the sound ray density can be made uniform.

[Example] Hereinafter, the present invention will be described in more detail based on an example shown in the drawings. It should be noted that the present invention is not limited by this.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus 1 according to one embodiment of the present invention.

In the ultrasonic diagnostic apparatus 1, a transmission sound ray SL is formed by the scan controller 9, the transmission delay circuit 3, the driver 4, and the probe 2 in a direction perpendicular to the probe 2 as shown by a broken line in FIG. The transmission sound ray SL is formed and moved according to time.

The transmission sound ray is provided by the common delay circuits 5 and 6, the individual delay circuits 7a and 7b, and the individual delay circuits 12a and 12b.
Ultrasonic echo signals are received from two directions slightly different in angle from SL.

The common delay circuit 6 is a variable delay circuit, and the scan controller 9 controls the delay time so that the focus distance increases as the depth of the living body increases.

The individual delay circuits 7a and 7b are also variable delay circuits,
As shown in FIG. 2 (a), the scan controller 9 controls the delay time so that the depth of the wedge-shaped characteristic is large in the shallow part of the living body and small in the deep part of the living body. Therefore, as shown in FIG. 2 (b), the steering angle in the receiving direction is large (θs) in the shallow part of the living body and small (θd) in the deep part of the living body.

Thus, the reception sound ray RL substantially parallel to the transmission sound ray SL can be formed by appropriately changing the focus distance by the common delay circuit 6.

Then, the total sound ray TL obtained by integrating the transmission sound ray SL and the reception sound ray RL becomes substantially parallel in the vicinity of the transmission sound ray SL, and as shown in FIG. Parallel,
A uniform density results.

The signal processing circuits 8a and 8b perform signal processing on the reception sound ray RL on both sides of the transmission sound ray SL, and output the result to the DSC 10.

The DSC 10 images the obtained data and displays the image on the CRT 11.

As understood from the above description, according to the ultrasonic diagnostic apparatus 1, since the sound ray density is uniform, the resolution is uniform. Further, the imaging process is simplified, and no image distortion occurs.

As another embodiment, there is one in which the present invention is applied to another scanning method (for example, convex scanning) for moving the communication sound ray SL.

[Effects of the Invention] According to the ultrasonic diagnostic apparatus of the present invention, the uniformity of sound ray density can be improved, and a uniform resolution can be obtained. In addition, signal processing is simplified, and image distortion does not occur.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to one embodiment of the present invention, FIG. 2 (a) is an explanatory diagram showing a change in wedge-shaped characteristics with depth, and FIG. 2 (b) is a steering angle depth. FIG. 3 is an explanatory diagram showing the distribution of sound rays according to the present invention, FIG. 4 is a block diagram of an example of a conventional ultrasonic diagnostic apparatus, and FIG. 5 is a conventional diagram shown in FIG. FIG. 6 is an explanatory diagram of a steering angle in the device, and FIG. 6 is an explanatory diagram showing a sound ray distribution in the conventional device shown in FIG. (Explanation of reference numerals) 1... Ultrasonic diagnostic apparatus 2... Probe 5... Common receiving delay circuit (fixed) 6... Common receiving delay circuit (variable) 7 a, 7 b. Individual receiving delay circuits (variable) 12a, 12b ... individual receiving delay circuits (fixed) 9 ... scan controller SL ... transmitting sound ray RL ... receiving sound ray TL ... total sound ray θs, θd ... ... the steering angle.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-120140 (JP, A) JP-A-59-225043 (JP, A) JP-A-58-138445 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) A61B 8/00-8/15

Claims (1)

(57) [Claims] An ultrasonic diagnostic apparatus for simultaneously receiving a plurality of sound rays by transmitting and receiving ultrasonic waves to and from a subject using a probe, wherein a reception focus is changed according to a depth direction of the subject. First delay means for delaying a signal received by the probe so as to cause the plurality of delay means to receive the signal delayed by the first delay means. Second delay means having a wedge-shaped delay characteristic and changing each of the wedge-shaped delay characteristics so as to change the angle of the received sound ray with respect to the probe in accordance with the depth direction. An ultrasonic diagnostic apparatus characterized by the above-mentioned.