JPH01185250A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To generate an ultrasonic diagnostic picture image of good quality by extracting a minimum beam width, corresponding to preset two or more focal positions, by simplified constitution and setting a reception fetching range. CONSTITUTION:A minimum width extracting part 1 calculates a minimum beam width of the beam width corresponding to an assigned focal position being found out from a previously created beam width table 4 or by a calculation expression. A data of the minimum beam width is stored in a beam width table 12, further divisions alpha, beta, being the division receiving an ultrasonic reflected wave by the focal positions alpha, beta, gamma, are obtained. The receiving time is determined corresponding to 'from zero to the division alpha' for the focal position alpha, 'from the division ' to the division beta' for the focal position beta and 'a division gamma thereafter' for a focal position gamma. This decreasing an amount of data promptly determining the optimum receiving time, an ultrasonic diagnostic picture image of good quality can be displayed.

Description

[Detailed Description of the Invention] [Summary] An ultrasonic diagnostic apparatus configured to set a receiving range for receiving and displaying reflected waves in correspondence with a focus position for transmitting ultrasound waves, which includes: The purpose of this system is to extract the minimum beam width corresponding to the position using a simple configuration and set the receiving range, and to generate high-quality ultrasound diagnostic images. There is beam width data for one ultrasonic line corresponding to the transmission focus position, equal to the number of positions that can be set for the transmission focus, and when one or more focus positions are specified on a specific line, the beam width data is A minimum width extraction unit that combines beam width data of a specific J line and extracts the narrower beam width, and the reception timing of reflected waves corresponding to each narrower transmission focus position extracted by this minimum width extraction unit. a depth calculation unit that calculates the depth at which the depth is to be switched; and a reception range setting unit that sets a reception time range corresponding to the depth calculated by the depth calculation unit, The configuration is such that a tomographic image is displayed based on reflected wave signals included in the reception time range.

[Industrial application field]

The present invention relates to an ultrasonic diagnostic apparatus configured to set a receiving range for receiving and displaying reflected waves in accordance with a focus position for transmitting ultrasonic waves.

[Conventional technique 4+l: i and the problem to be solved by the invention] In conventional ultrasound diagnostic equipment, the focus when transmitting ultrasonic waves is, for example, a four-stage focus, and the focus positions of these four stages are fixed. In many cases, it is. As the resolution of ultrasonic tomographic images becomes higher, it has become possible to set the transmission focus in six steps, and furthermore, to any focal length. In such an ultrasonic diagnostic apparatus, the reception period (reception time) of the ultrasonic reflected waves is also variable, and the reception of the ultrasonic reflected waves is controlled using a reception control signal of the received signal. For example, even when performing so-called two-step focusing in which the transmission focus is set at the positions indicated by two "△" or "mu" in Figure 7 (a), the two focal points are Δ” position of
The receiving and capturing range of the ultrasonic reflected wave can be changed between the time when the focus is focused on the two positions of ``M'' and the time of ``△'' in the upper row of Figure 7 (b) and the time of Pam in the lower row. It is necessary to display an ultrasonic tomographic image with good resolution by changing the ultrasonic wave at the best focused position by changing it as shown in FIG.

In addition, in Figure 17 (b), "*DS" represents the ultrasonic transmission timing, and ``ISAMP'' is the reception control signal of the ultrasonic reflected wave (to capture the ultrasonic reflected wave when it is at L level). represent. The first stage (second stage) in “I=SAMP” is shown in Figure 7 (
b) represents the reception capture range for the upper (lower) “△” or “Pam”.

Furthermore, if it is possible to set the transmission focus to any position, there is a method to create a table in advance for all combinations of transmission focus positions and find the reception period (reception time) of the reflected ultrasound wave from this table. Conceivable. This poses a problem in that the amount of data for all combinations of transmission focus positions becomes enormous.

Furthermore, in order to determine the reception time of the ultrasonic reflected wave, a method can be considered in which, when arbitrary focus positions are set, a division is made in the middle of these focus positions, and the reception capture range is determined in accordance with this. For example, as shown in Figure 8 (a), the two focus positions are 4 cm and 1 cm from the body surface.
If 2cm is set, the time range is divided at a position of 8cm between these, and the ultrasound is first focused and transmitted at a position 4cm from the body surface, and the ultrasound reflected wave is transmitted up to 3cm from the body surface. Figure 7"')
Set the receiving range of 'SAMP'.

Second, the ultrasonic waves are focused and transmitted at a position 12 cm from the body surface, and the reflected ultrasonic waves are received in a time range corresponding to 8 cm or more from the body surface.
” Set the reception capture range.

However, as shown in Figure 8 (b), at a position 8 cm from the body surface, as shown by diagonal lines in the figure, when the focus position is 12 cm, the ultrasound beam width is narrower and converges at the part where the ultrasound beam is converged. exists. For this reason, if the receiving range is divided in the middle of the focus point, the minimum ultrasound beam width cannot be obtained, resulting in a problem that the image quality of the ultrasound tomographic image deteriorates.

An object of the present invention is to extract the minimum beam width corresponding to a plurality of set focus positions using a simple configuration, set a receiving range, and generate a high-quality ultrasound diagnostic image.

[Means for solving problems]

Means for solving the problem will be explained with reference to FIG.

In FIG. 1, the minimum width extraction unit 1 extracts the minimum beam width corresponding to the input focus position from a beam width table 4.
Alternatively, it can be extracted by calculation.

The depth calculation unit 2 calculates the depth corresponding to the minimum beam width extracted by the minimum width extraction unit 1.

The reception range setting section 3 sets a reception time range in accordance with the depth calculated by the depth calculation section 2.

[Effect]

As shown in FIG. 1, in the present invention, the minimum width extraction unit 1 selects the minimum beam width corresponding to the input (designated) focus position by referring to a beam width table 4 prepared in advance. Alternatively, the depth calculation section 2 calculates the depth corresponding to the found minimum beam width, and the reception range setting section 3 focuses on each focus position according to the calculated depth. A receiving range is set for receiving the ultrasound transmitted by the receiver, and an ultrasound tomographic image is displayed based on the reflected ultrasound waves within the set receiving range.

Therefore, it is possible to calculate the receiving range corresponding to the minimum beam width at the designated focus position using a simple configuration and obtain a high-quality ultrasound tomographic image.

〔Example〕

Next, the configuration and operation of one embodiment of the present invention will be explained in detail using FIGS. 1 to 6.

In FIG. 1, the minimum width extraction unit 1 extracts the minimum beam width corresponding to the input focus position from a beam width table 4.
Or it can be found by calculation. this is,
This means finding the minimum beam width from among the designated focus positions from a beam width table 4 (a table in which beam widths for various focus positions are stored in advance), which will be described later. Also, this minimum beam width is the fifth
It may also be found out by calculation, as illustrated.

The depth calculation unit 2 calculates the depth corresponding to the found minimum beam width, that is, the distance (depth) from the ultrasound probe 11 to the position of the minimum beam width.

The reception range setting unit 3 sets a reception time range in accordance with the calculated depth.

The beam width table 4 is a table in which the beam width corresponding to the focus position (beam width corresponding to the depth) is determined in advance through experiments and stored in the table. The beam width is set to a value that is a predetermined value smaller than the intensity of the central ultrasonic wave when the ultrasonic wave is transmitted, for example, by 20 dB (details will be explained using FIG. 2).

Next, creation of the beam width table 4 will be explained in detail using FIG. 2.

FIG. 2(a) shows the relationship between depth (capture setting section) and beam width when setting at various focus positions.

This relationship is determined through experiments and the like. For example, in the leftmost one, when the ultrasonic probe 11 focuses on the focus position (1) and transmits the ultrasonic wave, the beam width at the position where the intensity is lower than the center intensity by 20 dB is determined as shown in the figure. Similarly, focus position (2) or nl
Find out sequentially.

FIG. 2(b) shows the beam width table 4.

In the figure, the horizontal direction represents what corresponds to each focus position (1) to n), and the vertical direction represents the capture setting section (1) to ml.

By creating the beam width table 4 in advance through experiments or the like as described above, it becomes possible to easily determine the beam width corresponding to the specified focus position.

Next, the operation of the configuration shown in FIG. 1 is performed according to the order shown in FIG.
This will be explained in detail using FIG. 4.

In FIG. 3, ■ indicates a state in which the focus position is set. This is, for example, the focus position A in Figure 4.
and B.

■ in the figure indicates a state in which beam width data is generated. This can be done by reading the beam width data corresponding to the focus position set in (■) in the figure from the beam width table 4 in Figure 2 (b), or by calculating the focus position as described later using Figure 5. This means calculating the corresponding beam width data.

In the figure, ■ indicates a state in which the beam widths are compared and the one with the minimum width is extracted. This means that among the beam widths read out or calculated at (■) in the figure, the one with the smallest width (the one with the smallest width corresponding to the set capture section) is extracted.

For example, in Figure 4 (a), the section from the body surface to point P (capture setting section) is extracted with the beam width for focus position A as the minimum width, and the section after point P is the beam width for focus position B. Take out as the minimum width.

In the figure, ■ indicates a state in which the depth at the time of reception is calculated.

This means calculating the depth (distance from the ultrasonic probe 11 to the minimum width object) at the time of reception of the object with the minimum width taken out in the figure (■).

For example, as shown in Fig. 4, for focus position A, the depth (distance) Ll from the body surface (depth zero) to point P, for focus position B, depth Lp and so on. calculate.

In the figure, ■ indicates a state in which the reception time corresponding to the transmission focus is determined. This is based on the depth of the minimum width calculated in (■) in the figure, and the time required to receive the ultrasonic reflected wave corresponding to this depth, for example, as shown in Figure 7 (b) already mentioned.
*SAMP" means to determine the time that is the reception acquisition range. For example, as shown in Figure 4 (b),
For the focus position A, the time T required to receive the ultrasonic reception wave reflected from the point "from depth zero to depth"
. -Lp, and for the focus position B, a time TLp- for receiving the ultrasonic reception wave reflected from a point "below the depth" is determined.

By the above procedure, when the ultrasonic waves are focused at the focus position A as shown in FIG. 4 (b), for example, the ultrasonic waves are The reception time is determined so that the ultrasound reflected waves can be received, and when the ultrasound is focused at the focus position B, the ultrasound from the position W (depth, subsequent position) shown using the two-dot chain line in the figure is determined. It becomes possible to determine the reception time so that the acoustic wave reflected wave can be received.

■ in the figure indicates a state in which a tomographic image is displayed. This means that a tomographic image is generated and displayed on the display based on the ultrasonic reflected waves during the reception time determined by the procedure indicated by ``■'' in the figure.

FIG. 5 and FIG. 6 show explanatory diagrams for extracting the minimum beam width by calculation. - When determining the beam width of a single-plate probe for boat fishing, it can be obtained from the lines ① and ② in Figure 6. Here, in the figure, a represents the radius, r represents the focal length, and λ represents the wavelength. Therefore, when calculating the beam width at distance X, may (Q, 5 λχ/a, laχ/r-a l )
......It can be obtained using the simple formula (1).

In Figure 5, α, β, and T represent the focus positions, and the division α (β) indicates the beam width when focused at focus position α (β), and the beam width when focused at focus position β (γ). represents the depth (intake setting section) that is larger than the beam width at the time.

FIG. 5(a) schematically represents the beam width calculated by the calculation formula when the focus positions α, β, and γ are specified. In the figure, the solid line represents the beam width at each depth when the ultrasonic wave is transmitted while focusing on the focus position α, the one-dot chain line on the focus position β, and the two-dot chain line on the focus position γ.

FIG. 5(b) shows the values of the minimum beam width stored when the focus positions α, β, and T are specified. The following will be explained in order.

First, the specified focus position α closest to the body surface
When the ultrasonic wave is transmitted by focusing on the focus position α, the beam width is calculated using a calculation formula in correspondence with the depth, and the beam width is calculated from the top to the bottom in the illustrated beam width table 12. and store everything.

Second, the second closest focus position β from the body surface is taken out, and the beam width corresponding to the depth is similarly calculated from the point of depth corresponding to the focus position α using a calculation formula. This calculated beam width and beam width table 12
The newly calculated beam width is compared with the beam width already stored in , and the newly calculated beam width is stored in such a manner that it is replaced only when it is smaller.

At this time, write down the illustrated delimiter α to be replaced by t
Shishite(.

Third, the focus position γ that is third closest to the body surface is taken out, and the beam width corresponding to the depth is similarly calculated from the depth point corresponding to the focus position β using a calculation formula. This calculated beam width and beam width table 12
The beam width is compared with the beam width already stored in , and the beam width is stored in such a manner that it is replaced only when it is smaller. At this time, the illustrated delimiter β that is to be reduced and replaced is memorized.

Through the above procedure, the minimum beam width data is stored in the beam width table 12, as shown in FIG.
In addition, a break α and a break β, which are the breaks at which the ultrasonic reflected waves due to the focus positions α, β, and T are received, are determined.

Then, for the focus position α, “separation α from zero
”, for focus position β, the reception time corresponding to “separation α to separator β”, and for focus position γ, “after separator γ” is determined, thereby reducing the amount of data and quickly optimizing. This makes it possible to determine the reception time and display high-quality ultrasound tomographic images.In particular, when calculating the beam width, only the beam width corresponding to the depth beyond the previously calculated focus position is calculated. , it is sufficient to store the calculated beam width in the beam width table 12 in such a manner that it is replaced only when the calculated beam width becomes smaller than the beam width stored in the beam width table 12. Even if the number of beam width calculations increases, there is an advantage that the number of beam width calculations does not increase so much.

〔Effect of the invention〕

As explained above, according to the present invention, the minimum beam width among the beam widths corresponding to a designated focus position is found from the beam width cheaple 4 created in advance or calculated by a calculation formula, and this finding is performed. Since the reception time is determined according to the minimum beam width determined or the calculated minimum beam width, the receiving range of ultrasound reflected waves to obtain high image quality can be determined by simple processing. be able to. Furthermore, even if the minimum beam width is calculated by calculation, it is only necessary to recalculate the beam widths for the focus position and beyond where the beam width was calculated last time, and store the smaller ones sequentially in a manner that replaces them in the beam width table. Even if the number of focus stages increases, the number of calculations for calculating the beam width does not increase so much, and the receiving range of the ultrasonic reflected waves can be quickly determined.

[Brief explanation of the drawing]

Part 1 is a configuration diagram of one embodiment of the present invention, Fig. 2 is an explanatory diagram for creating a beam width table, Fig. 3 is a flowchart to explain the operation of the present invention, Fig. 4 is an explanatory diagram for extracting the minimum beam width, and Fig. 5 ,
FIG. 6 is a diagram illustrating extraction of the minimum beam width by calculation, FIG. 7 is a diagram illustrating the operation of the prior art, and FIG. 8 is a diagram illustrating problems in the prior art. In the figure, 1 represents a minimum width extraction section, 2 a depth calculation section, 3 a reception range setting section, and 4 a beam width table. 11: Superhuman treatment 4 tense child 1
1N Su Homare Homare Homare 1111 -m-, --J Tetsu Yuki C (≧ △ M

Claims (1)

[Claims] There is beam width data for one ultrasonic line corresponding to only one transmission focus position specified on one ultrasonic line, and the beam width data for one ultrasonic line corresponds to the number of positions where the transmission focus can be set. A minimum width extraction unit (1) that combines beam width data of a specific line from the beam width data when one or more focus positions are specified on a line and extracts the narrower beam width; A depth calculation unit (2) that calculates the depth at which the reception timing of the reflected wave corresponding to each narrower transmission focus position extracted by the extraction unit (1) is switched; and a reception range setting section (3) that sets a reception time range corresponding to the calculated depth, and based on the signal of the reflected wave included in the reception time range set by the reception range setting section (3). An ultrasonic diagnostic device configured to display a tomographic image.