JPH04108439A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To prevent the frame rate from falling at the time of applying a focus of a multistage at the time of transmission by transmitting simultaneously each ultrasonic wave of different kinds of frequencies by a transmitting means, and changing the focus at every frequency thereof. CONSTITUTION:A transmitting means 2 consists of combination of oscillators 4A, 4B and a transmitting pulser circuit 5, transmits simultaneously each ultrasonic wave of different kinds of frequencies from an ultrasonic probe 1, and changes a focus at every frequency thereof. A receiving means 3 consists of combination of band pass filters 6A, 6B and phasing addition delay lines 7A, 7B, and receives a reflected wave from each sound field of a living body (not shown in the figure) focused by the transmitting means 2 as a receiving signal at every frequency through the ultrasonic probe 1. That is, the focus is applied to plural stages by simultaneous transmission of different kinds of frequencies, and an ultrasonic image is synthesized, based on the receiving signal of every frequency, therefore, even if the focus stage increases, the frame rate does not fall.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is an ultrasonic technology that obtains ultrasonic images that depict high-resolution images of a living body from the shallow to the deep areas by applying multiple focuses during transmission. This field relates to ultrasound diagnostic equipment, and particularly to improvements in ultrasound transmission technology.

(Prior Art) Conventionally, when this type of ultrasonic diagnostic apparatus performs multi-stage focusing during transmission, it first focuses on the depth direction of the living body while keeping the ultrasonic transmission frequency constant. ), the image is constructed by focusing on a short distance as shown in (B), then the image is constructed by focusing on a long distance as shown in (B) of the same figure, and then the images are combined as shown in (C) of the same figure. Images from each focus stage were combined on an image memory to improve the resolution of ultrasound images. In FIG. 4, an example of focusing in two stages is shown for simplicity of explanation, but in order to further improve the resolution, in reality, focusing is repeated in more stages, such as four stages.

(Problems to be Solved by the Invention) However, when focusing is repeated several times as in the conventional method, the frame rate of the ultrasound image decreases, resulting in poor real-time performance and inconvenience in diagnosis.

The present invention has focused on such a situation, and an object of the present invention is to provide an ultrasonic diagnostic apparatus that can prevent the frame rate from decreasing when multiple stages of focus are applied during transmission.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a transmitting means for simultaneously transmitting ultrasonic waves of different frequencies and changing the focus for each frequency; A receiving means that receives reflected waves from each sound field as received signals for each frequency, and an image synthesizing means that controls synthesizing an ultrasound image on an image memory based on each received signal received from the receiving means. It is characterized by comprising:

(Function) With the configuration of the ultrasonic diagnostic apparatus according to the present invention, the transmitting means simultaneously transmits ultrasonic waves of different frequencies, and the focus is changed for each frequency. The reflected waves from each focused sound field are received as received signals for each frequency.

Therefore, the image synthesis means can realize the synthesis of ultrasound images on the image memory without lowering the frame rate.

(Embodiment) FIG. 1 is a block diagram showing the functional configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.

In the ultrasonic diagnostic apparatus of this embodiment, a transmitting means 2 and a receiving means 3 are connected to an ultrasonic probe 1. and,
The transmitting means 2 includes oscillators 4A and 4B and a transmitting pulser circuit 5.
In combination with this, ultrasonic waves of different frequencies are simultaneously transmitted from the ultrasonic probe 1, and the focus is changed for each frequency. The receiving means 3 is a bandpass filter 6A.

6B and delay lines 7A and 7B for phasing and addition, the reflected waves from each sound field of a living body (not shown) focused by the transmitting means 2 are received as reception signals for each frequency via the ultrasonic probe 1. It is done like this.

Such an ultrasonic probe 1, transmitting means 2, receiving means 3
is controlled and operated by a system controller 8 provided as a control center for the entire system.

On the other hand, the system controller 8 has a function as an image composition means 10 that controls the composition of ultrasound images on the image memory 9 based on each reception signal received by the reception means 3. In the ultrasonic diagnostic apparatus of this embodiment, which is equipped with the various parts as described above, as schematically shown in FIG. To focus on the long distance LB, a pulse PA is generated by the oscillator 4A, and to focus on the long distance LB, a pulse PR is generated by the oscillator 4B. Here, pulse PA has a high frequency for short distances, whereas pulse P is for long distances, so it is better to have a low frequency for short distances in order to increase penetration.

When the ultrasonic probe 1 is driven by the transmission pulser circuit 5 using the pulses PA and PB thus created, the ultrasonic probe 1 transmits ultrasonic waves due to the pulse PA and ultrasonic waves due to the pulse PB to the depth direction of the living body. The pulses are transmitted almost simultaneously (several microseconds), and the focus is changed for each frequency of the pulses PA and PB to form a near-field sound field LA and a far-field sound field LB.

The reception signal from the ultrasound probe 1 that has received the reflected waves from the sound fields LA and P8 is received by bandpass filters 6A and 6B, and the above-mentioned deviation of several μsec is corrected through delay lines 7A and 7B for phasing and addition. When the image is sent to the image memory 9, the image for each focus stage (near-field sound field LA
and the image corresponding to the far-field sound field LB)
are combined and displayed as an image on the display 11.

In the above description of this embodiment, an example of focusing in two stages was shown for the sake of simplicity, but in order to further improve the resolution, focusing is actually performed in more stages, such as four stages.

In this way, according to this embodiment, different frequencies can be
The conventional technique is to transmit signals simultaneously at timings that can be considered to be substantially simultaneous, change the focus for each frequency to obtain multiple focus stages, and perform reception for each frequency to synthesize images. Compared to the case where multiple stages are focused in time series, as in the case of the above method, ultrasound images can be synthesized using one focus stage for each of the different frequencies. Therefore, it is now possible to obtain ultrasonic images with good resolution and good penetration using several types of focus while maintaining real-time performance.

〔Effect of the invention〕

As explained above, the ultrasonic diagnostic apparatus of the present invention focuses on multiple stages through simultaneous transmission of different frequencies, and synthesizes an ultrasound image based on received signals for each frequency. Even if the number increases, the frame rate does not drop, and real-time performance is maintained well.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the functional configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention, and FIG. 2 is for explaining a case where multiple stages of 74-cushion are applied by simultaneous transmission of different frequencies. , FIG. 3 is a diagram schematically showing an ultrasonic image synthesis screen, and FIG. 4 is an explanatory diagram when images are synthesized by a conventional ultrasonic diagnostic apparatus. ]...Ultrasonic probe 2...Transmission means 3...
・Receiving means 4A, 4B...Oscillator 5...
- Transmission pulser circuits 6A, 6B...Band pass filters 7A, 7B...Delay line for phasing and addition 8--System controller 9...Image memory 10...Image synthesis means 11...Display vessel

Claims (1)

[Claims] (1) A transmitter that simultaneously transmits ultrasonic waves of different frequencies and changes the focus for each frequency, and a receiver that receives reflected waves from each sound field focused by the transmitter as a reception signal for each frequency. An ultrasonic diagnostic apparatus comprising: an image synthesizing means for controlling the synthesizing of ultrasonic images on an image memory based on each received signal received by the receiving means.