JP2000316854A - Ultrasonic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of an ultrasonic image by setting a delay time corresponding to a focus position to the signal applied to or received by each of multiple parallel piezoelectric transducers of a probe, and determining the delay time based on the position of the transducers. SOLUTION: An ultrasonic transmission/reception section 2 is constituted of a transmission focus means 10, a transmitting means 11, a reception focus means 12 and a first-stage amplifying means 13, and a transmission/reception signal for each piezoelectric transducer is generated by the transmission focus means 10 based on the delay time information (focus data) by a memory means 9. An ultrasonic beam is generated by the reception focus means 12 from the delay-processed reception signal based on the delay time information and is outputted to an image processing means 3. The delay time for each piezoelectric transducer at the time of transmission and reception is calculated by a focus calculating means 8 based on the specified focus condition according to a measurement start instruction from an operation input means 7 and is stored in a memory means 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic apparatus, and more particularly, to an ultrasonic apparatus which is effective when applied to correction of a focus shift by an acoustic lens and an acoustic matching layer (matching layer) arranged on a transmitting surface side of a probe. It is about technology.

[0002]

2. Description of the Related Art A conventional ultrasonic apparatus supplies a multi-channel probe in which a number of transducers (transducer elements) are arranged, and a transmission signal for driving each transducer. In order to electrically focus the received signal from the vibrator, delay processing (phasing) according to the distance from the focal point (received wave focus point) is performed, and the phase of the received signal is adjusted. An ultrasonic transmission / reception unit that generates an ultrasonic beam having directivity in a predetermined direction by adding the subsequent reception signals, and corrects the reception signal strength depending on the reflection depth and emphasizes the contour of the ultrasonic image. An image processing circuit for performing image processing such as contour enhancement, and an ultrasonic beam sequentially scanned in a tomographic plane is collected to form an image (ultrasonic image) for one frame, and the ultrasonic image is used as a signal for a display device. Digital scan converter and table A display device based on a signal use to display the ultrasound image on a display screen, was composed of an operation input unit for inputting such measurement mode and measurement conditions.

[0003] An ultrasonic transmitting / receiving section includes a focus data storage means for storing a delay time for focusing an ultrasonic wave at a preset focus position as data (focus data), and a focus data storage section based on measurement conditions. Focus calculating means for reading and setting the delay time from the storage means, and transmitting and generating a transmission signal (transmission focus signal) in accordance with the delay time set by the focus calculating means and supplying the transmission signal to the vibrator Means, a reception phasing means for providing a delay time set by the focus calculation means to the reception signal output from each transducer, and a reception signal after the reception phasing is added, and a desired position is added. And an adding means for extracting the reflected wave.

In a conventional ultrasonic apparatus, from the viewpoint of securing real-time display and improving the image quality of an ultrasonic image, a so-called dynamic focus in which a delay time at the time of reception is varied and a focal point is moved deeper with time. A measurement technique referred to as "common" has been performed. However, the delay time given to the received signal is performed by switching the delay line in the analog phasing type ultrasonic device, and is stored in a memory or the like for storing the received signal after sampling in the digital phasing type ultrasonic device. This is performed by the time difference read from the means and the interpolation processing.

In the ultrasonic apparatus using the dynamic focus, the delay time given to each transducer in each scanning direction (raster) of the ultrasonic beam is different, and each transducer is also provided at each reception focus point in the same raster. The delay time to give was different. For this reason, in order to store the focus data corresponding to all the reception focus points in the focus data storage means having a limited capacity, the conventional ultrasonic apparatus uses about five reception focus points per raster. The focus data is stored, and the data at the reception focus point during that time is calculated and used from the data at the preceding and following reception focus points by interpolation.

On the other hand, a conventional probe has a structure in which a number of strip-shaped micro-vibrators are arranged on a sound absorbing material called a backing material. Each vibrator had a structure in which a piezoelectric element, a first acoustic matching layer, a second acoustic matching layer, and an acoustic lens layer were stacked from the side closest to the backing material. For this reason, the ultrasonic wave transmitted from the piezoelectric element toward the transmitting surface side of the probe is transmitted to the measurement target via the first and second acoustic matching layers and acoustic lens layers, which are made of different materials. Was to be done. Therefore, the ultrasonic waves transmitted from the piezoelectric elements have different sound velocities until they reach the measurement target. It is known that ultrasonic waves are refracted at the boundary surface when propagating through these layers. Therefore, in the conventional ultrasonic apparatus, the delay time in consideration of the change in the sound speed of the ultrasonic wave in the first and second acoustic matching layers and the acoustic lens layer and the refraction accompanying the change are stored in the focus data storage means as focus data. Was.

[0007]

SUMMARY OF THE INVENTION As a result of studying the above prior art, the present inventor has found the following problems.

[0008] The ultrasonic apparatus has features such as excellent soft tissue delineation performance that is difficult to be imaged by general X-ray imaging and the ability to avoid radiation exposure such as X-rays. It is widely applied to organs, urology, obstetrics and gynecology, etc., and further higher image quality is desired.

As a method of improving image quality, for example, in an ultrasonic apparatus using dynamic focus, it is conceivable to increase the number of focusing points, that is, the number of focusing points to be moved deeper with time. That is, by increasing the number of focus data in consideration of the refraction of the ultrasonic wave in the first and second acoustic matching layers and the acoustic lens layer, the intensity of the ultrasonic wave reflected at the desired reception focus point (the reception intensity) ) Can be considered to improve sensitivity and resolution.

However, in order to increase the number of reception focus points in the conventional ultrasonic apparatus, it is necessary to provide focus data for all the transducers per reception focus point. There is a problem that enormous storage capacity is required to secure them.
In addition, there is a problem that the manufacturing cost of the ultrasonic device is increased.

As another method of increasing the reception focus point in the conventional ultrasonic device, the amount of refraction and the speed of sound at each boundary surface are calculated in real time together with the movement of the focus point of the reception, and based on the obtained amount of refraction and sound speed. In this case, a method of determining the delay time given to each transducer by using the method can be considered. It is well known that the amount of refraction at each interface follows Snell's law.

However, in order to calculate the amount of refraction at each interface, a higher-order higher-order equation having terms such as trigonometric functions derived by Snell's law must be solved.
Even when calculation is performed using a relatively high-performance computer called a workstation, a calculation time of about one minute is required for one reception focus point, which is one of the features of the ultrasonic apparatus. There was a problem that real-time measurement could not be realized.

It is an object of the present invention to provide an ultrasonic apparatus capable of improving the quality of an ultrasonic image.

Another object of the present invention is to provide a technique capable of improving the resolution of an ultrasonic image.

Another object of the present invention is to provide a technique capable of calculating the delay time of each transducer corresponding to all the reception focus points at a high speed.

Another object of the present invention is to provide a technique capable of improving diagnostic efficiency.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0018]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

(1) A probe having a plurality of transducers arranged side by side and delay setting means for setting a delay time according to a focus position for a signal applied to each transducer or received by each transducer according to a focus position. In an ultrasonic apparatus that forms an ultrasonic image of a measurement target from a received signal in which the delay time is set, the delay setting unit calculates a delay time to be set for each transducer based on the position of the transducer. A delay operation means is provided.

(2) In the ultrasonic apparatus according to the above (1), the delay calculating means stores a delay physical parameter optimized for each focus position;
Calculating means for calculating a delay time set for each transducer based on the selected delay physical parameter.

(3) In the ultrasonic apparatus according to (2), the delay physical parameter is a variable of a focus position of the probe and a position of the transducer is a variable of delay time. Function, wherein the storage means includes first storage means for storing the delay time of the focus position, and second storage means for storing a delay physical parameter specified by the focus position.

(4) In the ultrasonic apparatus according to any one of (1) to (3), the delay function using the position of the vibrator as a variable is located on the wave transmitting side of the piezoelectric element. This is a function obtained by approximating a function for each focus point in consideration of a change in the refraction and the speed of sound of the ultrasonic wave caused by the disposed thin film layer.

In the ultrasonic apparatus described in (1) to (4) above, the physical parameters of the probe are used as variables of the focus position, and the physical parameters of the probe, which are variable values of the focus position, are specified. By setting the function to be performed as a delay function, the increase in the number of data due to an increase in the focus position can be made only by the physical parameters of the probe, so that the number of focus positions can be more easily increased. . As a result, the resolution of the ultrasonic image can be improved, so that the image quality of the ultrasonic image can be improved. Also, since the image quality of the ultrasonic image can be improved,
Diagnosis efficiency can be improved.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) of the invention.

In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 is a view for explaining a schematic configuration of an ultrasonic apparatus according to an embodiment of the present invention, wherein 1 is a probe, 2 is an ultrasonic transmitting / receiving section, 3 is an image processing means, Is a digital scan converter (DSC), 5 is an image display unit, 6 is a control circuit, 7 is an operation input unit, 8 is a focus calculation unit, 9 is a focus data storage unit, 10 is a transmission focus unit, and 11 is a transmission unit. Means, 12 is a reception focusing means, and 13 is a first stage amplifying means.

In FIG. 1, a probe 1 generates an ultrasonic wave according to a drive signal, transmits the ultrasonic wave to a measurement object, receives an ultrasonic wave reflected in the measurement object, and receives the ultrasonic wave. This is a known probe that outputs an electric signal corresponding to a sound pressure as a received signal, and is, for example, a linear scanning probe.

The ultrasonic transmission / reception unit 2 is a known ultrasonic transmission / reception unit including a transmission focus unit 10, a transmission unit 11, a reception focus unit 12, and a first-stage amplification unit 13, and a driving unit for driving a probe. A signal is supplied, and an ultrasonic beam having directivity in a predetermined direction is generated from a received signal output from the probe 1.

The transmission focus means 10 is a known transmission focus means for generating a transmission signal for each transducer based on the delay time information (focus data) supplied from the focus data storage means 9. Also, the wave transmitting means 1
Reference numeral 1 denotes a known transmitting unit that generates a drive signal that is a high-voltage signal for driving the probe based on the transmitted signal generated by the transmission focusing unit 10.

The first-stage amplifier 13 is a well-known amplifier for amplifying a weak signal from the probe 1.

The reception focusing means 12 includes a well-known reception phasing means (not shown) for giving a predetermined amount of delay to the reception signals from the respective vibrators, and a delay processing which is a reception signal after the reception phasing. A known adding means (not shown) for detecting only an ultrasonic wave coming from a desired direction as an ultrasonic beam by adding later received signals. The receiving focus unit of the present embodiment generates an ultrasonic beam from the received signal subjected to the delay processing based on the delay time information from the focus data storage unit 9 and outputs the ultrasonic beam to the image processing unit 3.

The image processing means 3 corrects the received signal strength depending on the depth of the ultrasonic wave transmitted to the subject, so-called gray scale correction for correcting the relationship between the received signal strength and the brightness at the time of display, And a well-known image processing means 3 for performing image processing such as contour enhancement (enhancement) for enhancing the contour of the image.

The DSC 4 converts the corrected ultrasonic beam, which is a signal output from the image processing means 3, into a digital signal, for example, and converts it into an ultrasonic image having a display cycle of the image display means 5. A well-known DS that combines a sound wave image with display information such as measurement conditions and display magnification to generate a display image
C, which converts the display image into the input format of the image display means 5 and outputs it.

The image display means 5 is a well-known display device such as a television monitor or a liquid crystal display device using a CRT, and displays a measured ultrasonic image.

The control means 6 is, for example, based on information such as the measurement conditions and the type of the probe input from the operation input means 7 provided as an operation panel of the apparatus. Is a well-known control means for controlling the operation of.

The focus calculation means 8 calculates the delay time of each transducer at the time of transmission / reception at any time based on the probe type and the focus position information at the time of transmission / reception indicated by the control means 6 which is the focus condition. An arithmetic unit that performs an arithmetic operation. For example, an external storage device such as a magnetic disk device, an optical disk device, or a semiconductor memory called a memory connected to the information processing device included in the ultrasonic device according to the present embodiment; This can be realized by a program operating on the processing device. However, the details of the focus calculation means 8 will be described later. Note that the focus condition in the specification of the present application refers to a transmission signal and a reception signal for transmitting and receiving ultrasonic waves as if the shape of the front surface of the transducer, which is the transmission and reception surface of the probe, is formed as if it were concave. Required when calculating the time difference given to the wave signal, for example,
Information such as a probe type, a scanning method, and focus position information (including the number of focus points) at the time of transmission / reception.

The focus data storage means 9 includes, for example,
Each of the main memory and an external storage device such as a magnetic disk device or a magneto-optical disk device mounted on the information processing apparatus constituting the ultrasonic apparatus according to the present embodiment. Stores the delay time for each transducer. However, the delay time stored in the focus data storage means 9 is different from the storage of the delay time in the conventional ultrasonic apparatus, and only the delay time satisfying the focus condition specified by the operation input means 7 can be stored. Sufficient capacity is enough.

Next, an operation for obtaining a tomographic image (B-mode image) with the ultrasonic apparatus according to the present embodiment will be described with reference to FIG. However, for the sake of simplicity, a description will be given of a dynamic focus operation in which the transmission is performed at a fixed focus and the reception is performed at 16 reception focus points per raster.

The operation start of the ultrasonic apparatus according to the present embodiment is a measurement start instruction from the operation input means 7, and the control means 6 instructs each means based on a preset procedure by the measurement start instruction. Is output.

First, the focus calculation means 8 calculates the focus condition based on the focus condition input (instructed) from the control means 6.
The delay time of each transducer at the time of transmission / reception is calculated, and the obtained delay time is output to the focus data storage means 9 and stored.

When the calculation of the delay time by the focus calculation means 8 is completed, the transmission focus means 10 generates an ultrasonic signal of the designated transmission frequency, and delays the ultrasonic signal with the delay for each transducer. The signal given the time is supplied to the transmission means 11 as a transmission signal. The delay time at this time is based on the delay time information read from the focus data storage means 9, and this delay time information is based on the acoustic lens disposed on the wave transmitting surface, which is the front surface of the vibrator, and the first and second acoustic lenses. The refraction at the boundary of the acoustic matching layer and the change in the speed of sound at each layer are also taken into consideration.

In the transmitting means 11, the transmitting focus means 1
A high-voltage signal (drive signal), which is a drive voltage of the transducer, is generated from the transmission signal supplied from 0 and supplied to each transducer of the probe 1.

Each transducer of the probe 1 to which the drive signal is supplied transmits an ultrasonic wave according to the drive signal. At this time, in the probe of the present embodiment, a strip in which layers made of different materials such as an acoustic lens, a first acoustic matching layer, a second acoustic matching layer, and a piezoelectric element are sequentially stacked from the transmitting surface side. The vibrators have a structure in which the transducers are juxtaposed in the longitudinal direction of the probe. Therefore, the ultrasonic wave generated by the piezoelectric element is transmitted into the measurement target after propagating through the second acoustic matching layer, the first acoustic matching layer, and the acoustic lens. That is, at the interface between the layers, refraction in accordance with Snell's law is repeated, and then transmitted into the object to be measured.

In the present embodiment, as described above, the transmission signal output from the transmission focusing means 10 is given a delay time in consideration of refraction at the boundary surface of each layer. The transmitted ultrasonic wave is accurately focused at a preset focus point position.

The reflected wave reflected in the object to be measured is received by the probe 1 and output to the first-stage amplifier 13 as a received signal. At this time, the reflected wave received by the probe 1 propagates through the acoustic lens, the first acoustic matching layer, and the second acoustic matching layer in the reverse order of the time of transmission, and then returns to the piezoelectric element. Is converted into a received signal. Therefore, as in the case of transmitting a wave, the reflected wave reaches the piezoelectric element after being refracted at the boundary surface of each layer.

The received signal amplified by the first stage amplifying means 13 is subjected to delay processing by each of the receiving phasing means of the receiving focus means 12, and then added and output to the image processing means 3. In the present embodiment, similarly to the time of transmission, the delay time of each wave phasing unit is based on the delay information read from the focus data storage unit 9 and includes an acoustic lens,
The delay time takes into account the refraction at each boundary surface between the first and second acoustic matching layers. Therefore, it is possible to accurately correct the phase shift of the received signal due to the refraction of the reflected wave in the path from the reception focus point to each piezoelectric element.

The received signal input to the image processing means 3 is
After receiving signal strength correction, gray scale correction, contour emphasis, etc., according to the depth of the receiving focus point, the signal is output to the DSC 4. The received signal input to the DSC 4 is first converted into a digital signal and then sequentially stored in a memory. When one tomographic image can be collected, the tomographic image is output to the image display means 5. The image is displayed on the display screen as an ultrasonic tomographic image. (Focus Principle) FIG. 2 is a diagram for explaining the relationship between the focus position in the ultrasonic device and the position of each transducer.
First, based on FIG. 2, the acoustic lens arranged on the wave transmitting surface of the probe 1 and the second case in which the refraction at the boundary surface between the first and second acoustic matching layers and the change in sound speed in each layer do not occur. The focus position at the r-th raster position and the delay time given to each transducer will be described. However, in the following description, the number of transducers used for transmitting and receiving ultrasonic waves is seven.
The case of two linear scanning transducers will be described.
It is needless to say that the present invention is not limited to this, and other scanning type probes such as a convex type may be used. Also, it goes without saying that ultrasonic waves may be transmitted and received by all transducers, such as a sector-type probe. Furthermore, it is needless to say that the present invention can be applied at the time of transmission.

As is apparent from FIG. 2, for example, in the case of the third focus position indicated by A3 on the raster 32, the r-th vibrator 31 to which the reflected wave reaches the earliest.
And the (r-3) th and the (r +) th where the reflected wave arrives the latest
With respect to the third vibrator 31, when the sound speed in the measurement target is v, a time difference of the following equation 1 occurs. Here, a3 is a distance from the focus position A3 to the front surface of the r-th vibrator, and R3 is a distance from the r-th vibrator to the (r + 3) -th vibrator.

[0049]

(Equation 1) Here, when the distance between the respective vibrators called the vibrator pitch is changed, the distance R3 changes. Therefore, when the focus position and the sound velocity are fixed, the time difference with respect to the R-th vibrator to which the reflected wave arrives first becomes a function of the vibrator pitch. That is, the delay time of each transducer can be expressed as a function of the transducer pitch. The function of the delay time given to each transducer at this time is as follows, where the distance R3 from the r-th transducer 31 to the (r + 3) -th transducer 31 in Equation 1 is replaced by a transducer pitch × 3. The function is represented by Expression 2.

[0050]

(Equation 2) Therefore, in the present embodiment, as shown in FIG. 3, the delay time given to each transducer when the refraction of the ultrasonic wave and the change in the speed of sound by the acoustic lens and the first and second acoustic matching layers are considered. among the function, in particular, the function g _n at the n-th focus position, a function for the same n-th focus position, as shown in equation 2 is not considered refraction and sound velocity change of the ultrasound, low-stage- The load on the calculation of the delay time is reduced by substituting the function f (x (n)) of the oscillator pitch, which is a low-order equation. Also,
By setting a variable associated with a change in the focus position as information having a small data amount called a transducer pitch, it is possible to minimize the data amount associated with an increase in the focus position. However, x (n) in the function f (x (n)) of the present embodiment indicates the transducer pitch corresponding to the n-th focus position.

Next, a procedure for calculating the function f (x (n)) according to the present embodiment will be described with reference to FIG. The transducer pitch x (n) calculated according to the following procedure is used offline for ultrasonic measurement by the ultrasonic apparatus of the present embodiment.
It is set in advance. The number of reception focus points in the present embodiment is N.

First, as shown in FIG. 3, when considering the refraction of ultrasonic waves and the change in sound speed due to the acoustic lens and the first and second acoustic matching layers, each vibrator at the n-th focus position is moved. A function g _n indicating the delay time to be given is calculated.

Next, a function f () of each transducer at the n-th focus position and the delay time when the refraction of the ultrasonic wave and the change in the speed of sound by the acoustic lens and the first and second acoustic matching layers are not considered. With the vibrator pitch of x (n)) as a variable, the function g _n is fitted or optimized as shown by the arrow.

More specifically, when the refraction of the ultrasonic wave and the change in the speed of sound due to the acoustic lens and the first and second acoustic matching layers are considered, each of the first to N-th focus positions has The given delay time Tn is calculated. next,
The function f in the case where the refraction of ultrasonic waves and the change in sound speed due to the acoustic lens and the first and second acoustic matching layers are not considered.
With respect to (x (n)), the vibrator pitch is used as a variable for each of the first to Nth focus positions to approximate the plot point of the delay time Tn and the vibrator. At this time, the transducer pitch x (n) is converted to a function f (x
(N)).

In the present embodiment, the case where the refraction of ultrasonic waves and the change in sound speed due to the acoustic lens and the first and second acoustic matching layers are considered is considered, and the position of each transducer at each focus position is determined. Delay time Tn given to each oscillator
As a variable corresponding to the focus position of the function g _n, as a variable has been decided to use a vibrator pitch which is a physical parameter of the probe, which corresponds to the focus position of the function g _n in the approximation formula, for example, a linear scan Needless to say, the pitch may be the transducer pitch or the line address in the case of the probe of the type, and the pitch of the transducer or the radius of curvature of the wave transmitting surface may be in the case of the probe of the convex scanning type. Moreover,
As is clear from FIG. 2 and Expression 1, it goes without saying that the sound speed used at the time of measurement may be a variable corresponding to the focus position of the function g _n in the approximate expression.

(Focus Calculation Means) FIG. 4 is a diagram for explaining a schematic configuration of the focus calculation means of the present embodiment. Hereinafter, the delay in the focus calculation means 8 of the present embodiment will be described based on FIG. The procedure for deriving time information will be described. In FIG. 4, a ROM 41 stores, for example, a transducer pitch x (n) corresponding to each focus position in a function of a delay time in which a physical parameter of the probe is optimized for each focus position at the time of input / output waves. Is a well-known storage unit that stores table data that stores
This can be realized by using an external storage device such as a magnetic disk device, an optical disk device, or a nonvolatile memory using a semiconductor. However, the transducer pitch x corresponding to each focus position stored in the ROM 41
(N) differs depending on the probe type, and stores table data storing transducer pitches x (n) corresponding to respective focus positions for probes usable in the ultrasonic device. . However, the ROM 41 is not limited to an external storage device that is always connected to the information processing device that configures the ultrasonic device. For example, the ROM 41 uses a semiconductor arranged in a probe used in the ultrasonic device. Needless to say, the data may be stored as table data in a storage unit using a nonvolatile memory or the like.

The calculating means 42 is a well-known calculating means for calculating the delay time given to each transducer based on the transducer pitch x (n) given from the ROM 41, and constitutes, for example, the ultrasonic apparatus. This can be realized by a program that operates on the information processing device.

Next, FIG. 5 shows an operation flow for explaining the procedure for specifying the approximate expression in the focus calculating means of the present embodiment. Hereinafter, based on FIG. 5, the focus calculating means 8 of the present embodiment will be described. Will be described.

The start of this flow, that is, the start of the operation of the focus calculation means 8 is the focus position information (focus point number information) from the control means 6.

First, a search is made based on the focus position information input from the control means 6, and the ROM 41 reads the transducer pitch x (0) corresponding to the 0th focus position n = 0.
To identify. Next, the calculating means 42 applies the vibrator pitch x (0) to the expression shown in Expression 2 to obtain an approximate expression f (x (0)) corresponding to the 0th reception focus position. Next, the approximate expression f (x (0)) is output to the focus data storage unit 9 as delay time information, and stored in the focus data storage unit 9.

The ROM 41 which outputs the approximate expression f (x (0)) corresponding to the 0th focus position to the arithmetic means 42
Then adds 1 to the focus position n = 0,
It is determined whether the result, that is, the operation result of (n + 1) is equal to N (step 52).

In the determination at step 52, 0 + 1 (n
= N + 1) is equal to N, the process ends.

On the other hand, in the determination at step 52, 0+
If 1 is not equal to N, the ROM 41 sets 0 + 1 = 1 (n = n + 1) obtained by adding 1 as the focus position, returns to step 51, and corresponds to the first focus position n = 1. The oscillator pitch x (1) is specified. Next, the calculating means 42 applies the transducer pitch x (1) to the expression shown in Expression 2 to obtain an approximate expression f (x (1)) corresponding to the first reception focus position. Next, the approximate expression f (x (1)) is output as delay time information (step 51).

As described above, the ROM 41 sequentially adds 1 to the focus position n until the focus position n reaches the number N of focus points, obtains approximate expressions for all focus positions, and outputs the approximate expressions to the focus data storage means 9.

When the operator performs ultrasonic scanning using the apparatus, the focus information (approximate expression) calculated in the above-described procedure and stored in the focus data storage means 9 is read, and the focus information corresponding to the corresponding focus point is read. The delay time is calculated, and an appropriate focus corresponding to the focus point is formed.

As described above, in the ultrasonic device according to the present embodiment, the influence of the acoustic lens and the first and second acoustic matching layers is reduced by the strict delay time based on Snell's law, by the higher and higher order. Using a function optimized with the sound velocity directly related to the propagation time and propagation path of the ultrasonic wave between each transducer and the focus position and the transducer pitch, which is a physical parameter of the probe, without solving the equation This makes it possible to correct the effects of the acoustic lens and the first and second acoustic matching layers, so that the calculation load of the delay time can be greatly reduced. Therefore, it is possible to reduce the time required to calculate the delay time given to each transducer, and thus it is possible to perform real-time measurement even when the probe type or the measurement condition is changed. As a result, it is not necessary to hold the delay data corresponding to all the probe types and the measurement conditions, so that it is possible to easily increase the focus position with an increase in the amount of delay data, and to increase the height of the ultrasonic image. Image quality can be improved.

However, the ultrasonic apparatus according to the present embodiment employs an analog phasing type ultrasonic apparatus in which a delay time given to a received signal is switched by switching a delay line (not shown) connected from each transducer to a signal line. However, the present invention is not limited to this, and it is possible to convert a received signal output from the probe 1 into a digital signal and store the converted received signal temporarily in a memory or the like. It is needless to say that the present invention can be applied to a digital phasing type ultrasonic apparatus that performs a delay process based on a read time difference from the information storage unit and the interpolation process.

As described above, the invention made by the present inventor is:
Although specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the present invention, and it is needless to say that various modifications can be made without departing from the gist of the present invention. .

[0069]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) The image quality of an ultrasonic image can be improved.

(2) The resolution of an ultrasonic image can be improved.

(3) The delay time for each transducer corresponding to all the reception focus points can be calculated at high speed.

(4) The diagnostic efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a schematic configuration of an ultrasonic apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a relationship between a focus position and each transducer position in the ultrasonic apparatus.

FIG. 3 is a diagram for explaining a relationship between a transducer position at each reception focus point and a delay time given to each transducer in the ultrasonic apparatus according to the present embodiment.

FIG. 4 is a diagram for explaining a schematic configuration of a focus calculation unit according to the present embodiment.

FIG. 5 is an operation flow for describing a procedure for specifying an approximate expression in a focus calculation unit according to the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Ultrasonic transmission / reception part, 3 ... Image processing circuit,
4 Digital scan converter (DSC), 5 Image display unit, 6 Control circuit, 7 Operation input unit, 8 Focus calculation circuit, 9 Focus data storage circuit, 10 Transmission focus circuit, 11 Transmission wave Circuit 12, receiving wave focus circuit 13, initial stage amplifier circuit 31, oscillator 32,
Raster, 41 ROM, 42 arithmetic means.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2G047 AC13 BA03 BC13 DA02 DB04 DB05 EA01 EA07 EA09 EA12 GB02 GB16 GB17 GB25 GB29 GF18 GF19 GF22 GG09 GG16 GG21 GG39 GG41 GH01 GH04 GH07 GH17 GJ00 EE01 BB01 EE13 GB04 GB05 GB22 GB24 GB27 HH24 HH25 HH37 JB03 JB13 JB17 JC08 JC16 KK03 KK31 LL04 LL05

Claims (1)

[Claims] A probe having a plurality of transducers arranged in parallel, and delay setting means for setting a delay time according to a focus position for a signal applied to each transducer or received by each transducer, An ultrasonic apparatus for forming an ultrasonic image of a measurement target from a received signal in which the delay time is set, wherein the delay setting means calculates a delay time to be set for each transducer based on a position of the transducer. An ultrasonic apparatus comprising a calculating means.