JP3193514B2 - Digital scan converter for ultrasonic diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital scan converter for an ultrasonic diagnostic apparatus, and more particularly, to a digital scan converter for an ultrasonic diagnostic apparatus.
The present invention relates to a digital scan converter of an ultrasonic diagnostic apparatus that generates display data obtained by rotating a tomographic image in a display screen.

[0002]

2. Description of the Related Art FIG. 6 is an overall configuration diagram of a digital scan converter of a conventional ultrasonic diagnostic apparatus. The digital scan converter 51 includes a pre-memory 2, a frame memory 3, an xy generator 4, and an r-θ converter 7.

[0003] The pre-memory 2 converts the data collected by the sector scan into the address (r, θ) corresponding to the distance on the sound ray and the scan angle to the ultrasonic scan data Ds.
(R, θ). The frame memory 3 stores addresses (x, x) corresponding to the horizontal and vertical directions of the display screen.
The display data Dp (x, y) is stored in y). The xy generator 4 outputs an address (x,
y) are continuously generated and output as a write address to the frame memory 3. The r-θ converter 7 is shown in FIG.
As shown in the figure, the address (x,
y) is converted to an address (r, θ) on the pre-memory 2,
Output as a read address of the pre-memory 2. In addition,
This address conversion is such that the center line of the sector is oriented vertically in the display screen.

Next, the operation of the digital scan converter 51 will be described. First, when the doctor applies the probe to the affected part of the patient, the address (r, r,
The ultrasound scan data Ds (r, θ) necessary for displaying a tomographic image is stored corresponding to (θ).

Next, an xy generator 4 continuously generates an address (x, y) and outputs it as a write address to the frame memory 3. r-θ converter 7
Is the address (r, θ) at which the ultrasonic scan data Ds (r, θ) corresponding to the address (x, y) is stored
Is calculated and output as the read address of the pre-memory 2. Therefore, the ultrasound scan data Ds corresponding to the address (x, y) generated by the xy generator 4
(R, θ) is read from the pre-memory 2 and written into the frame memory 3 as display data Dp (x, y).

The display data Dp (x,
y) is read out and displayed by a display device (not shown) in the order of horizontal scanning and vertical scanning of the display screen.

[0007]

In the digital scan converter 51 of the conventional ultrasonic diagnostic apparatus, r-.theta.
The converter 7 performs the address conversion so that the center line of the sector is oriented in the vertical direction of the display screen. Therefore, when the probe is pointed directly below, the direction of the probe matches the direction of the tomographic image, and there is no problem. However, when the probe is tilted, the direction of the probe and the direction of the tomographic image do not match, and there is a problem that the observer is likely to be confused. In order to avoid this, it is only necessary that the tomographic image can be rotated on the display screen. For example, when the probe D is tilted by the angle α as shown in FIG. 8, it is sufficient that a tomographic image Sa obtained by rotating the original tomographic image S1 by the angle α as shown in FIG. 9 can be displayed. Therefore, an object of the present invention is to provide a digital scan converter of an ultrasonic diagnostic apparatus capable of generating display data obtained by rotating a tomographic image on a display screen by an arbitrary angle with a simple configuration.

[0008]

According to the present invention, there is provided a digital scan converter for an ultrasonic diagnostic apparatus, which converts ultrasonic scan data of a sector type or a convex type to generate display data of a tomographic image. In the scan converter, the address (r, θ) consisting of the distance on the sound ray and the scanning angle of the ultrasonic beam
And a pre-memory for storing the ultrasonic scan data Ds (r, θ) corresponding to the display data Ds (r, θ), and the display data Dp corresponding to the addresses (x, y) corresponding to the horizontal and vertical directions of the display screen.
A frame memory for storing (x, y); an xy generator for generating the address (x, y) and outputting the address as a write address to the frame memory;
An offset means for adding an offset amount (−Δx, −Δy) to an address (x, y) generated by a −y generator, and a rotation address (x−Δx, y−Δy) obtained by rotating the offset (x−Δx, y−Δy) by an angle α. x to calculate x ', y')
-Y rotation means and the calculated rotation address (x ',
y ′) is converted to a pre-memory address (r ′, θ ′) and output as a read address of the pre-memory.
θ converter, wherein the xy rotation means comprises:
Cosine output means for outputting [cos α] for the angle α, sine output means for outputting [sin α] for the angle α, and [x-Δx] and [cos α] after offset by the offset means First multiplying means for multiplying, and [y-Δ after offset by the offset means.
y] and [sin α], subtraction means for subtracting the output of the second multiplication means from the output of the first multiplication means and outputting the result as a horizontal rotation address x ′, and the offset means [X-Δ after offset by
x] and [sin α], fourth multiplication means for multiplying [y−Δy] and [cos α] after offset by the offset means,
The present invention is characterized in that it comprises an adding means for adding the output of the multiplying means and the output of the fourth multiplying means and outputting the result as a vertical rotation address y '.

[0009]

In the digital scan converter of the ultrasonic diagnostic apparatus according to the present invention, the display position of the tomographic image is translated by adding the offset amount (-.DELTA.x, -.DELTA.y) to the address (x, y). (X-Δx, y-Δy)
Is rotated by an angle α, and the obtained rotation address (x ′,
y ′) is converted into a read address (r, θ) of the pre-memory by the r-θ converter. If this is shown in a specific example, the addresses (X, X) on the frame memory 3 shown in FIG.
When data is written to (Y), the address (X, Y) is set to the offset amount (-Δx, -Δ) as shown in FIG.
y), and rotated by an angle α about the xy origin as shown in FIG. 5C, and the obtained rotation address (X ′, Y ′) is converted into the r-θ converter explained in FIG. 7 and converted into the pre-memory 2 as shown in FIG.
The upper address (R ', Θ') is obtained. If the data of this address (R ′, Θ ′) is read from the pre-memory 2 and written to the address (X, Y) of the frame memory 3, the tomographic image can be rotated on the display screen. In FIG. 5, the address (X, Y) and the address (R,
In order to make it easy to understand the correspondence with the tomographic image in (i), the sectors and their center lines are shown.

In general, a coordinate P (x, y) obtained by rotating a coordinate P (x, y) counterclockwise by an angle α is represented by Q (x ',
y ′) is represented by x ′ = x · cos α−y · sin α (1) y ′ = x · sin α + y · cos α (2) The xy rotation means is obtained by the above equation (1) and (2)
The rotation address (x ', y') is obtained by the equation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. It should be noted that the present invention is not limited by this. FIG. 1 is an overall configuration diagram of a digital scan converter of an ultrasonic diagnostic apparatus according to the present invention. The digital scan converter 1 includes a pre-memory 2, a frame memory 3, and an xy generator 4.
, Offset circuit 5, xy rotation circuit 6, r-θ
And a converter 7.

The pre-memory 2 converts the data collected by the sector scan into the address (r, θ) corresponding to the distance on the sound ray and the scan angle to the ultrasonic scan data Ds.
(R, θ). The frame memory 3 stores addresses (x, x) corresponding to the horizontal and vertical directions of the display screen.
The display data Dp (x, y) is stored in y). The xy generator 4 outputs an address (x,
y) are continuously generated and output as a write address to the frame memory 3. The offset circuit 5 has an xy
The offset amount (−Δx, −Δy) is added to the address (x, y) generated by the generator 4. xy rotation circuit 6
Calculates the rotation address (x ′, y ′) obtained by rotating (x−Δx, y−Δy) after the offset by the angle α.
The r-θ converter 7 converts the address (x, y) on the frame memory 3 into the address (r) on the pre-memory 2 in such a manner that the center line of the sector is oriented vertically in the display screen as shown in FIG. , Θ), and outputs it as a read address of the pre-memory 2.

FIG. 2 is an internal block diagram of the offset circuit 5 and the xy rotation circuit 6. In the offset circuit 5,
The adders 11 a and 11 b add the offset amount (−Δ) to the address (x, y) transmitted from the xy generator 4.
(x, −Δy), and (x−Δx,
y−Δy) to the xy rotation circuit 6.

The xy rotation circuit 6 includes a cosine calculator 21
a, 21b, sine calculators 22a, 22b, multipliers 23a, 23b, 23c, 23d, a subtractor 24, and an adder 25. Cosine calculator 21
a and 21b are [c] with respect to the angle α input from the doctor.
osα] is calculated. Note that these cosine calculators 21
a and 21b may be the same cosine calculator.
Alternatively, a table may be used. Sine calculators 22a, 22
2b is [sin] with respect to the angle α input from the doctor.
α] is calculated. Note that these sine calculators 22a, 22
2b may be the same sine operation unit. Alternatively, a table may be used. The multiplier 23a calculates [x-Δx] · [cosα] by multiplying [x-Δx] and [cosα] after the offset corresponding to the horizontal direction. The multiplier 23b outputs [x−
Δx] is multiplied by [sin α] to obtain [x−Δx] ·
[Sin α] is calculated. The multiplier 23c calculates [y-Δy] · [sinα] by multiplying [y−Δy] after offset corresponding to the vertical direction and [sinα].
The multiplier 23d multiplies [y−Δy] after the offset corresponding to the vertical direction by [cos α], and obtains [y−Δ
y] · [cos α] is calculated. The subtractor 24 calculates [y−Δy] · [s] calculated by the multiplier 23c from [x−Δx] · [cos α] calculated by the multiplier 23a.
inα], and outputs the result as the horizontal rotation address x ′. The adder 25 adds [x−Δx] · [sin α] calculated by the multiplier 23b and [y−Δy] · [cos α] calculated by the multiplier 23d to obtain a vertical rotation address y Output as'.

Next, the operation of the digital scan converter 1 will be described. First, when the doctor applies the probe to the affected part of the patient, the pre-memory 2 stores the address (r, θ).
, Ultrasonic scan data Ds necessary for displaying a tomographic image is stored. At this time, as shown in FIG. 3, when the probe D is tilted, the doctor inputs the tilt into the xy rotation circuit 6 as the clockwise angle α.

Next, the xy generator 4 continuously generates an address (x, y) and outputs it as a write address to the frame memory 3. The offset circuit 5
Address (x, y) generated by xy generator 4
, An external offset amount (−Δx, −Δy) is added.

The xy rotation circuit 6 calculates (x
-Δx, y-Δy) is rotated by an angle α (counterclockwise) about the xy origin (x ′, y ′).
y ′) is calculated. Specifically, the subtractor 24 calculates [y−Δy] · [s] calculated by the multiplier 23c from [x−Δx] · [cos α] calculated by the multiplier 23a.
inα], and outputs the result as the horizontal rotation address x ′. The adder 25 adds [x−Δx] · [sin α] calculated by the multiplier 23b and [y−Δy] · [cos α] calculated by the multiplier 23d, and performs vertical rotation. Output as address y '.

The r-.theta. Converter 7 calculates the address (r ', .theta.') At which the ultrasonic scan data Ds corresponding to the rotation address (x ', y') is stored, and reads the read address of the pre-memory 2. Output as

As described above, the display data of the tomographic image Sa obtained by rotating the tomographic image S1 clockwise by the angle α is written in the frame memory 3 as described above with reference to FIG. Display data Dp of frame memory 3
(X, y) is read out by a display device (not shown) in the order of horizontal scanning and vertical scanning on the display screen and displayed. Thus, as shown in FIG. 4, a tomographic image Sa rotated in accordance with the inclination of the probe D is displayed.

In the above embodiment, the offset circuit 5 of the digital scan converter and the xy rotation circuit 6
Are constructed in hardware, but may be constructed in software using a program that realizes an operation such as an adder or a multiplier. In the present invention, the sector system and the convex system are equivalent, and the present invention can be applied to the convex system as described above. Further, the tomographic image may be rotated in conjunction with a probe angle detector.

[0021]

According to the digital scan converter of the ultrasonic diagnostic apparatus of the present invention, a tomographic image can be rotated and displayed by the angle α with a simple configuration. Thus, the direction of the probe and the direction of the tomographic image can be matched. Conversely, the direction of the tomographic image can be selected independently of the direction of the probe.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a digital scan converter of an ultrasonic diagnostic apparatus according to one embodiment of the present invention.

FIG. 2 is an internal block diagram of an offset circuit and an xy rotation circuit.

FIG. 3 is a conceptual diagram when imaging is performed with a probe tilted.

FIG. 4 is a conceptual diagram of a tomographic image displayed by the apparatus of FIG.

FIG. 5 is a diagram illustrating the principle of address translation according to the present invention.

FIG. 6 is an overall configuration diagram of a digital scan converter of a conventional ultrasonic diagnostic apparatus.

FIG. 7 is a conceptual diagram when imaging is performed with the probe tilted.

8 is a conceptual diagram of a tomographic image displayed by the device of FIG.

FIG. 9 is a diagram illustrating the principle of conventional address translation.

[Explanation of symbols]

 1,51 digital scan converter 2 pre-memory 3 frame memory 4 xy generator 5 offset circuit 6 xy rotation circuit 7 r-θ converter 11a, 11b adder 21a, 21b cosine calculator 22a, 22b sine calculator 23a, 23b , 23c, 23d Multiplier 24 Subtractor 25 Adder

Claims (1)

(57) [Claims] 1. A digital scan converter of an ultrasonic diagnostic apparatus for converting ultrasonic scan data of a sector system or a convex system to generate display data of a tomographic image, comprising a distance on a sound ray and a scan angle of an ultrasonic beam. The ultrasonic scan data Ds (r, r) corresponding to the address (r, θ)
θ), a frame memory for storing display data Dp (x, y) corresponding to addresses (x, y) corresponding to the horizontal and vertical directions of the display screen, and the address (x, y). ) And outputs it as a write address to the frame memory, and an address (x,
an offset means for adding an offset amount (−Δx, −Δy) to y), and x for calculating a rotation address (x ′, y ′) obtained by rotating (x−Δx, y−Δy) after the offset by an angle α. -Y rotation means and the calculated rotation address (x ', y') is stored in the pre-memory address (r ', θ')
And an r-θ converter that outputs the result as a read address of the pre-memory. The xy rotation means outputs cosine output means for outputting [cos α] with respect to the angle α, [Sin
α], first multiplication means for multiplying [x−Δx] and [cos α] after offset by the offset means, [y−Δy] and [y−Δy] after offset by the offset means. sinα], and a second multiplying means for multiplying the second
Subtraction means for subtracting the output of the multiplication means and outputting the result as a horizontal rotation address x '; third multiplication means for multiplying [x-Δx] and [sinα] after offset by the offset means; Fourth multiplying means for multiplying [y-Δy] and [cosα] after offset, and addition for adding the outputs of the third multiplying means and the fourth multiplying means and outputting the result as a vertical rotation address y ' And a digital scan converter of the ultrasonic diagnostic apparatus.