JPH0443211Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention writes echo signal data obtained by transmitting and receiving ultrasonic waves into an image memory, compresses and converts the echo signal data when reading it out.
The present invention relates to an ultrasonic diagnostic apparatus that performs nonlinear quantization of decompression transform.

(b) Prior art and its problems Generally, in an ultrasonic diagnostic apparatus having an image display function, echo signal data obtained by transmitting and receiving ultrasonic waves by a transducer is temporarily stored in an image memory, and then, Echo signal data stored in the image memory is read out in synchronization with TV scanning and displayed as a diagnostic image on a CRT monitor.

By the way, it is not a good idea to store echo signal data obtained by transmitting and receiving ultrasonic waves in an image memory as it is because the storage capacity becomes large. Therefore, some conventional ultrasonic diagnostic apparatuses of this type are configured to perform nonlinear quantization on echo signal data. That is, a compression conversion circuit is provided at the data input stage of the image memory, and a decompression conversion circuit is provided at the data output stage of the image memory, and after the echo signal data is compressed and converted by the compression conversion circuit, it is stored in the image memory. When reading the echo signal data from the image memory, the echo signal data compressed by the decompression conversion circuit is decompressed and restored to the original echo signal data, and then output to the CRT monitor. There is.

On the other hand, echo signal data obtained by transmitting and receiving ultrasonic waves has a biased distribution, as shown by the solid line and broken line distribution curves in FIG. however,
Conventional devices do not take this point into consideration, and the echo signal data is uniquely compressed and decompressed using a single conversion curve. For this reason, depending on the diagnostic site, echo signal data with a dense intensity level distribution may be roughly compressed and converted, and as a result, the diagnostic image may be displayed coarsely and become difficult to view.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to make it possible to obtain an appropriate diagnostic image according to the region to be diagnosed.

(c) Means for solving the problem In order to achieve the above object, the present invention provides an image memory that stores echo signal data obtained by transmitting and receiving ultrasonic waves, and a selection switch for various body position display marks. In an ultrasonic diagnostic apparatus equipped with a code generator that generates a body position display code according to the operation, a compression conversion circuit in which a plurality of compression conversion curves corresponding to the diagnosis target area are stored in the data input stage of the image memory. A decompression conversion circuit storing a plurality of decompression conversion curves corresponding to the compression conversion curves is provided in each data output stage of the image memory, and
A code generator is commonly connected to the compression conversion circuit and the decompression conversion circuit, and the body position display code from the code generator is given as a selection signal for the compression conversion curve and the decompression conversion curve.

(d) Effect When you operate the selection switch of the body position display mark,
The code generator generates a body position display code corresponding to the selection switch, and this code is sent to the compression conversion circuit as a compression conversion curve selection signal, and to the decompression conversion circuit as a decompression conversion curve selection signal. Each is given as a selection signal. As a result, an appropriate compression conversion curve corresponding to the diagnosis site is selected from among the plurality of compression conversion curves stored in the compression conversion circuit. At the same time, a decompression conversion curve corresponding to the compression conversion curve is selected from a plurality of decompression conversion curves stored in the decompression conversion circuit. Therefore, the echo signal data is subjected to appropriate nonlinear quantization depending on the diagnostic site.

(E) Embodiments The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 is a block diagram showing an embodiment of the ultrasonic diagnostic apparatus of the present invention. In the figure, numeral 1 is an ultrasonic diagnostic device, and 2 is an A/D that digitizes echo signals output from a transducer (not shown).
Transducer 4 is an image memory that stores echo signal data. A compression conversion circuit 6 is provided at the data input stage of the image memory 4, and a decompression conversion circuit 8 is provided at the data output stage of the image memory 4. As shown in FIG. 2, the compression conversion circuit 6 generates a plurality of compression conversion curves depending on the part to be diagnosed.
s ₁ and s ₂ are stored, and the decompression conversion circuit ₈ , as shown in _FIG . It consists of a ROM that stores ₁ and _t2 .

10 is a D/A converter that converts the image data passed through the decompression conversion circuit 8 into analog data, and 12 is a CRT monitor that displays echo signal data as a diagnostic image. Further, 14 is a selection switch operation for selecting various body position display marks as shown in FIG. 4, and 16 is a code generator that generates a body position display code in response to the operation of the selection switch 14. A generator 16 is commonly connected to the compression conversion circuit 6 and the decompression conversion circuit 8. 18 is a CPU that controls writing and reading of echo signal data into and from the image memory 4.

In the ultrasonic diagnostic apparatus 1 having such a configuration, when one of the selection switches 14 corresponding to the region to be diagnosed is operated, a body position display code is uttered from the code generator 16 in response to this operation, and this body position display The code is given to the compression conversion circuit 6 as a selection signal for a compression conversion curve (for example, s ₁ ), and to the decompression conversion circuit 8 as a selection signal for a decompression conversion curve (for example, t ₁ ). It will be done. As a result, a compression conversion curve s 1 and a decompression conversion curve _{t 1} adapted to the region to be diagnosed are set in the compression conversion circuit 6 and the decompression conversion circuit 8, respectively.

Therefore, the echo signal obtained by transmitting and receiving ultrasonic waves is digitized by the A/D converter 2 and then input to the compression conversion circuit 6. The compression conversion circuit 6 compresses and converts the input echo signal data based on the already selected compression conversion curve _s1 .
That is, data conversion is performed by narrowing the quantization step where the intensity level distribution of the echo signal data is dense, and widening the quantization step at other locations where the intensity level distribution is coarse. Therefore, the storage capacity is smaller than when the echo signal data is stored as is in the image memory 4. The echo signal data compressed and stored in the image memory 6 is read out by the CPU 18 at a predetermined timing synchronized with TV scanning, and the read echo signal data is inverted in the decompression conversion circuit 10. It is decompressed and transformed based on the compression transformation curve t ₁ and restored to the echo signal data before the compression transformation. After the restored echo signal data is converted into analog data by the D/A converter 10, it is displayed on the CRT monitor 12 as a diagnostic image.

(F) Effect As described above, according to the present invention, since the compression conversion curve and the decompression curve are selected in conjunction with the selection switch, it is possible to obtain an appropriate diagnostic image according to the region to be diagnosed. It has excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the ultrasonic diagnostic device of the present invention, Fig. 2 is a characteristic diagram showing a compression conversion curve, Fig. 3 is a characteristic diagram showing an inverse compression conversion curve, and Fig. 4 is a body position diagram. FIG. 5, which is an explanatory diagram of the display marks, is a histogram showing the distribution of intensity levels of digitized echo signal data. 1... Ultrasound diagnostic device, 4... Image memory, 6
...Compression conversion circuit, 8...Decompression conversion circuit, 16
...Code generator.

Claims (1)

[Claim for Utility Model Registration] An image memory that stores echo signal data obtained by transmitting and receiving ultrasonic waves, and a code generator that generates body position display codes in accordance with the operation of selection switches for various body position display marks. In the ultrasonic diagnostic cutting apparatus, a compression conversion circuit in which a plurality of compression conversion curves corresponding to a diagnosis target region are stored in a data input stage of the image memory, and a compression conversion circuit storing a plurality of compression conversion curves according to a diagnosis target region in a data output stage of the image memory. A decompression conversion circuit storing a plurality of decompression conversion curves corresponding to 1. An ultrasonic diagnostic apparatus characterized in that an ultrasonic diagnostic code is provided as a selection signal for a compression conversion curve and a decompression conversion curve.