JPH04128711U - ultrasound imaging device - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to realize an ultrasonic imaging device that reduces the required amount of delay lines. [Configuration] A variable delay line group 12 that is inserted into each channel and changes the delay amount according to a received continuous dynamic focus control signal and a phase error correction signal, and a received signal that is input from the variable delay line group 12 when a strobe signal is input. Phase comparator circuit 17 that calculates the phase error by
and a PA that outputs a phase error correction signal to the variable delay line group 12 based on the phase error signal from the phase comparator circuit 17.
It includes a C control section 18 and a controller 13 that generates a dynamic focus control signal and also generates a strobe signal when the sound ray faces forward.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention is an ultrasonic imaging system with an array transceiver that performs phase conjugate transmission and reception. Regarding the location.

0002

[Conventional technology]

Ultrasonic imaging equipment emits ultrasound signals from an ultrasound probe into the subject. , an ultrasound probe receives signals reflected from tissues or lesions within the subject, and then A device that displays tomographic images formed by reflected signals on a CRT for diagnostic purposes. be. By the way, the ultrasound signal propagates inside the subject, is reflected by a reflector, and returns to the body. In the process of propagating the waves and receiving them by the ultrasonic probe, the waves inside the body, which is the propagating medium, Since each tissue is not homogeneous, there is a phase difference between each sound wave when it reaches the ultrasound probe. A phenomenon called the phase cancellation effect occurs, which distorts the image produced by the received ultrasound waves. live. Due to this effect, the delay distribution of reflected waves within the aperture plane of the ultrasonic probe is reduced according to theory. It won't become a problem. For this reason, the aperture is enlarged to improve resolution and improve image quality. Even if you try to do so, it won't get any better.

0003 To solve this problem, there is a method of performing phase conjugate transmission and reception. Phase conjugate transmission and reception Communication involves selecting two received signals from among the received signals and calculating the phase difference between the channels. , determine the amount of phase correction by finding the non-ideal component contained therein, and then calculate the phase correction. A method of correcting the phase of the received signal based on the amount (hereinafter referred to as PAC (Phase Aberr) (Correction). As the two received signals , how to select two signals from each adjacent element of an ultrasonic element, and how to organize all received signals. There is a method of performing PAC processing by comparing the phase-added signal and one channel of each channel. be.

0004 Whichever method you choose, conventional phased array type transmitter/receiver Stick to the door array, and therefore balance swinging the sound ray and doing PAC. In order to achieve this goal, the operating conditions were subject to various restrictions.

FIG. 2 is a diagram showing an example of a circuit that performs conventional PAC processing. In the figure, the element array 1 is composed of 64 elements EL ₀ to EL ₆₃ . 2 is a main delay line group consisting of 64 variable delay lines connected to each element. 3 is a PAC delay line group consisting of 64 variable delay lines that correct the phase of the output signal of each delay line constituting the main delay line group 2; 4 is a PAC delay line group 3 of each element EL ₀ to _{EL 63} ; This is an adder that inputs and adds the outputs of the 64 channels of received signals together with the main delay line group 2 and the PAC delay line group 3. The phased and summed signals are input to the phase detector 5. Although the phase detector 5 and the integrator 6 are provided for each of the 64 element circuits, only the Kth circuit of the element EL _K will be described here. The phase detector 5 receives the received signal output from the main delay line 2 _K that delays the signal from the element EL _K , and performs phase detection using the output of the adder 4 as a reference signal.

[0006]This phase detection output is input to the delay line 3 _K of the PAC delay line group 3 to change the amount of delay and correct the phase error.

[0007]

[Problem that the idea aims to solve]

By the way, with such a conventional phased array type ultrasound imaging device, The PAC processing to be performed is to stick to a phased array and perform electronic beam scanning. In an attempt to balance the demands of PAC and PAC, he accepted various restrictive conditions. That is, when appropriate elements in element array 1 are extracted and compared, required for all individual elements (or channels) to direct sound rays in all directions. In addition to requiring a variable length delay line, it also requires a separate delay line for the PAC. When trying to measure the phase error, the PAC diode is connected to each channel as shown in Figure 2. A lay line was also required, and in the end all channels had a main delay line and a delay for PAC. delay lines and many delay lines. Ta.

[0008] This invention was made in view of the above points, and its purpose is to The object of the present invention is to realize an ultrasonic imaging device with reduced requirements.

[0009]

[Means to solve the problem]

The present invention to solve the above problems has a phased array type probe and a receiver. In ultrasound imaging equipment that performs continuous wave dynamic focusing, each channel The received continuous dynamic focus control signal and phase error correction signal are a variable delay line group that changes the amount of delay depending on the signal; and a variable delay line group that changes the amount of delay depending on the signal. The output signal of each channel is input, and when the strobe signal is input, the input signal is A phase comparison circuit that calculates the phase error based on the phase comparison circuit and a phase error output of the phase comparison circuit. A signal that changes the amount of delay of each delay line constituting the variable delay line group. a PAC control section that outputs a signal, and a dynamic four-way The focus position is continuously changed according to the depth of the echo source by sending a focus control signal. At the same time, when the sound ray faces the front, a strobe signal is generated and the phase comparison circuit is The device is characterized in that it includes a controller for inputting data to the channel.

0010

[Effect]

The received signal received by the element array passes through a group of variable delay lines to Input to phase comparison circuit. In the phase comparator circuit, the control is performed when the sound ray faces forward. The phase error is detected by comparing the phase of the received signal using the strobe signal input generated by the controller. Calculates the amount of correction and sends it to each constituent derailleur of the variable delay line group via the PAC control unit. input to the dynamic focus control signal from the controller. Change the amount of leyline delay.

[0011]

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing only a receiving section of an apparatus according to an embodiment of the present invention. The transmitter is omitted because it is the same as a general device. In the figure, parts equivalent to those in FIG. 2 are given the same reference numerals. In the figure, 11 is a first-stage amplifier group that amplifies the received signal of each channel formed by each element E ₀ to _{E 63} of the element array 1, and 12 is a first-stage amplifier group that amplifies each output signal of the first-stage amplifier group 11 for the purpose of dynamic focusing. A variable delay line group provides a delay amount, and the focus position is changed by changing the delay amount according to the depth of the echo source in response to a dynamic focus control signal from the controller 13.

[0013] 14 is a controller 13 for transmitting signals from each channel of the variable delay line group 12. The main beam former performs phasing and addition according to the commands of the cross point switch 15 and It consists of a main delay line 16, and a cross point is controlled by a controller 13. The switch 15 is appropriately switched to form a desired sound ray.

[0014] 17 is the output of the variable delay line group 12 of each channel when the sound ray faces the front. Phase that calculates the amount of phase correction between the average value of the signal and the signals of its neighboring channels This is a comparison circuit. The sound ray for phase comparison in the phase comparison circuit 17 faces the front. The signal of each channel when the signal is turned is input to the phase comparison circuit 17 at that time. It is identified by the strobe signal from the controller 13.

[0015] 18 is a variable delay line group 1 based on the amount of phase correction of the output of the phase comparison circuit 17; This is a PAC control unit that performs control to determine the amount of delay for each channel of No. 2. variable de The delay line group 12 is controlled by the dynamic focus control signal described above. It is controlled by the PAC control unit 18 for phase correction.

[0016] Next, the operation of the embodiment configured as described above will be explained. in element array 1 The received ultrasonic waves are converted into electrical signals, amplified by the first stage amplifier group 11, and then It passes through the variable delay line group 12. The variable delay line group 12 is a controller The depth of the echo source is controlled by 13 dynamic focus control signals. The delay amount of each channel is changed so as to change the focal position accordingly. variable de The output of the delay line group 12 is input to the main beam former 14, and the cross point The signals are phased and summed by the switch 15 and the main delay line 16 and output to the subsequent circuit. be done.

[0017] On the other hand, the output signal of the variable delay line group 12 is also input to the phase comparison circuit 17. Ru. The phase comparator circuit 17 converts the input channel signals into At the time when the strobe signal issued by the controller 13 is input, the parallel Measure the average value of the signals of all channels at that time and the signal of the channel near the front. The phase error is determined by comparing the phases. This phase error data is stored in the PAC control section 18. is input into the variable delay line group 12 and changes the amount of delay given to each delay line of the variable delay line group 12. the signals in the channels forming the sound rays in the vicinity of the front-facing sound rays. Ru. The above correction data can also be used to correct and scan sound rays at other azimuth angles. have them do it.

[0018] The PAC processing according to the above embodiment is based on the following empirical rule. That is, the PAC Correction data means that a group of data obtained for a certain sound ray also applies to sound rays in the vicinity of that sound ray. It is considered to be valid without any major errors. That is, a certain sound with respect to azimuth space This is because the line data does not change dramatically with respect to the data of adjacent sound rays. Therefore, Measure and correct only one sound ray when facing the front, and apply it to all other sound rays. Even if the above correction data for the front sound ray is applied, the sound rays near the front sound ray cannot be corrected. is sufficient. In this sense, the amount of data collection for phase difference correction is significantly reduced. can be set.

[0019] As explained above, according to this embodiment, a sound ray is shaken, and the waved sound ray is In contrast to the conventional method in which PAC processing is performed on each Since it performs PAC processing, there is no need to pass through the main beamformer. The camera can perform PAC processing in near real-time with only one page. become.

[0020] If depth resolution is added to the correction data, continuous dynamic focusing of received waves can be achieved. It also helps correct errors in dregs. In this way, the average sound speed of the target water or living body can be adjusted depending on the temperature, etc. You will be able to keep up with the changes as they change. Also, from this, the flatness of the object You can also measure the average temperature.

[0021] If there is no error in the reception continuous dynamic focus, the reception compensation Of the correction data for normal use, those related to a certain desired depth are also applied to the transmitting side. You can also make corrections from the side so that the beam becomes sharp at the destination point.

[0022]

[Effect of the idea]

As explained in detail above, according to the present invention, only one main beamformer is required; In addition, it is no longer necessary to provide a main delay line for each channel as in the past, making it easier to implement. The practical effects are great.

[Brief explanation of drawings]

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

FIG. 2 is a circuit diagram of a device that performs conventional PAC processing.

[Explanation of symbols]

1 element array 12 Variable delay line group 13 Controller 14 Main beamformer 17 Phase comparison circuit 18 PAC control section

Claims (1)

[Scope of utility model registration request] [Claim 1] In an ultrasonic imaging device having a phased array probe and performing continuous dynamic focus of received waves, the probe is inserted into each channel to determine the amount of delay using a continuous dynamic focus control signal of received waves and a phase error correction signal. a variable delay line group (12) that changes the
A phase comparison circuit (17) receives the output signal of each channel of the variable delay line group (12) and calculates a phase error based on the input signal when a strobe signal is input; a PAC control unit (1) that outputs a signal that changes the amount of delay of each delay line constituting the variable delay line group (12);
8) and sends a dynamic focus control signal to the variable delay line group (12) to continuously change the focus position according to the depth of the echo source, and generates a strobe signal when the sound ray faces forward. and a controller (13) for inputting the signal to the phase comparison circuit (17).