JPH07213519A - Ultrasonic tomogram device - Google Patents

Abstract

PURPOSE:To provide an ultrasonic tomogram device that receives a reflected ultrasonic wave from an examined body using a probe and allows an operator to gradually adjust the dynamic range of an image against the reflected signal. CONSTITUTION:A reflected ultrasonic wave from the inside of the body is received using a probe 1 in contact with a examined body, the received signal is sent to an analog image processing circuit 4 via an echo sounder phasing circuit 3, the signal is logarithmic-compressed in the circuit and detected with a detection circuit 6, and the output is multiplexed by a control voltage with a multiplexer 17 in such that an operator uses a slide volume 16 attached on an operation panel 13 to gradually adjust the dynamic range. The output is displayed as an ultrasonic tomogram image on a TV monitor 12 via an A/D converter 10 and DSC 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic tomography device used for medical examination of a living body.

[0002]

2. Description of the Related Art Generally, an ultrasonic tomography apparatus converts an ultrasonic wave reflected signal from a living body into a received signal by an ultrasonic probe contacted with a subject, amplifies this output by a first stage amplifier, and receives the received wave. Received waves are focused by the phasing circuit, input to the digital scan converter through the analog image processing circuit,
It is a device that converts ultrasonic scanning into TV scanning and displays an ultrasonic tomographic image on a television monitor. By the way, in diagnosing a living body with this device, for example, for a circulatory organ such as the heart, an image quality with good followability to its structure and movement is preferred, while for an abdominal organ such as the pancreas, its movement Although it is not so strict to follow, it is demanded that subtle changes in internal organization can be seen well. For this reason,
Generally, an analog image processing circuit is provided with a means for switching the image quality of an ultrasonic image, one of which is switching of a dynamic range.

FIG. 2 is a graph showing various dynamic ranges of an ultrasonic image displayed on a TV. The horizontal axis represents the strength of the ultrasonic signal received by the ultrasonic probe, and its maximum value is 0 dB. The vertical axis represents the gradation of the image when it is displayed on the TV monitor. In the figure, as an example,
There are 64 gradations from 0 to 63. Where -60
A case where an ultrasonic signal from dB to 0 dB is displayed with 64 gradations is called a dynamic range of 60 dB, and
A case where an ultrasonic signal of 50 dB to 0 dB is displayed in 64 gradations is called a dynamic range of 50 dB.
In addition to this, the figure shows that the dynamic range is 40 dB and 30.
The case of dB is also shown.

By switching the dynamic range, the quality of the image on the television monitor can be switched. Generally, when displaying an image of the abdomen or peripheral blood vessels, the dynamic range is widened to make it easier to see subtle tissue changes. On the other hand, in displaying an image of the heart or the like, the dynamic range is narrowed so that the contour of the structure and the inside of the heart chamber can be easily seen.

Next, FIG. 3 shows an example of a block diagram of a circuit system of a conventional ultrasonic tomography apparatus. First, there is the probe 1 that is brought into contact with the subject, which is configured by arranging a plurality of strip-shaped ultrasonic transducers in parallel. This probe 1 is driven by an ultrasonic wave transmission circuit 2 and irradiates an ultrasonic beam to the subject side. Then, the reflected signal of the ultrasonic wave from the subject is received by the probe 1, and its output is input to the ultrasonic wave wave rectifying circuit 3. This wave phasing circuit 3
Is for delaying and combining the ultrasonic reflection signals from the above-mentioned transducers. Then, the output from the wave receiving and phasing circuit 3 is input to the analog image processing circuit 4, where signal processing is performed.

In the signal processing, first, the logarithmic compression circuit 5 receives and compresses all the signals output from the wave receiving and phasing circuit 3, and then the detection circuit 6 detects the signals to obtain a DC signal. Here, gain control is performed by adjusting the DC level, then the amplification degree of the amplifier 7 is changed, and the gain is controlled by the fixed limiter value of the limiter circuit 8 to control the dynamic range. And
The edge enhancement circuit 9 performs edge enhancement processing.

Next, the output from the analog image processing circuit 4 is input to the A / D converter 10 and digitized, and its output is DSC (digital scan converter) 1.
1, is converted into a TV coordinate system, converted into an analog signal again, and then displayed as an ultrasonic tomographic image of the subject on the television monitor 12.

Here, the operation panel 13 is provided with operation keys necessary for driving the entire apparatus. In this example, the gain control signal A for adjusting the DC level in the detection circuit 6 is used. And the operation key 15 for adjusting the dynamic range control signal B for changing the amplification degree of the amplifier 7.
It has and.

Next, the operation of the conventional dynamic range control will be described with reference to FIG. First, of the outputs of the wave rectifying circuit 3, the signal level to be displayed as an image is generally 40 to 60 dB, whereas the TV monitor 12 has 64 gradations and about 36 dB, so the wave phasing is performed. The output of the circuit 3 is compressed by the logarithmic compression circuit 5, detected, and then sent to the DSC 11 via the amplifier 7 and the limiter circuit 8. Here, the graph in FIG. 4 shows the output V _b (a) of the logarithmic compression circuit 5, the output V _c (b) of the detection circuit 6, and the analog image processing circuit 4 of the output V _a of the wave receiving and phasing circuit 3. The final output V _d (c) is shown. Also, the signal level that you actually want to display, that is, the dynamic range is
It is about 40 dB in the circulatory system and about 60 dB in the abdomen, but FIG.
In the graph of, 60 dB is shown.

First, by the logarithmic compression circuit 5 of 90 dB,
All signals of the received wave phasing signal are received, and then detected by the detection circuit 6 into a DC signal. Here, gain control is performed by adjusting the DC level. That is, as shown in the graph (b), the signal level is moved up and down,
The minimum level of the display signal is set to 0V. That is, the brightness becomes zero on the television monitor 12. Next, the dynamic range is controlled as shown in graph (c) by changing the amplification degree of the amplifier 7 and controlling it with a fixed limiter value. And the maximum level of the display signal is 1V
And set this to the maximum brightness of the television monitor 12.

By switching the dynamic range as described above, the image quality of the image displayed on the television monitor 12 can be changed.

[0012]

However, in the above-mentioned conventional ultrasonic tomography apparatus, the amplification degree of the amplifier 7 for controlling the dynamic range is determined by the operator using the constants of several kinds of resistors prepared in advance on the operation panel 13. It was changed by selecting with the operation key 15. For this reason,
The dynamic range that can be set is limited to several types, and there is a possibility that the optimum dynamic range may not be set when displaying an image.

The present invention has been made in order to solve the above problems, and provides an ultrasonic tomography apparatus which enables an operator to set an optimum dynamic range for an image in any case. The purpose is to

[0014]

In order to achieve this object, in the present invention, the dynamic range can be switched steplessly with respect to a reflected signal received by a probe that transmits and receives ultrasonic waves in the subject. Provide adjustable means.
A multiplier is used to switch the dynamic range so that stepless adjustment can be performed.

[0015]

In the ultrasonic tomography apparatus thus constructed, a multiplier is used in place of the amplifier, and the detection output and the control voltage are multiplied to control the dynamic range. The control voltage is controlled by the operator himself. The dynamic range can be set infinitely by adjusting the encoder or slide volume provided above. Therefore, the operator himself / herself can select the optimum image quality for the images of the circulatory organ, the abdomen, the peripheral blood vessels, and the like by an extremely simple operation.

[0016]

1 is a block diagram showing an embodiment of a circuit system of an ultrasonic tomography apparatus according to the present invention.

First, the probe 1 has a structure in which a large number of strip-shaped ultrasonic transducers are arranged side by side. However, the probe 1 is driven by the ultrasonic wave transmission circuit 2 to contact an object to be inspected. Irradiate an ultrasonic beam. Then, the probe 1 also receives the reflected signal of the ultrasonic wave from the subject, and its output is input to the ultrasonic wave wave rectifying circuit 3. In this wave receiving and phasing circuit 3, the reflected signals of the ultrasonic waves from the respective vibrators are delayed and combined. Then, the output from the wave receiving and phasing circuit 3 is input to the analog image processing circuit 4, where signal processing is performed.

In the analog image processing circuit 4, first,
The logarithmic compression circuit 5 receives and compresses all the signals output from the wave receiving and phasing circuit 3, and then the detection circuit 6 detects them.
DC signal. Then, here, the gain control is performed by adjusting the DC level, and then the amplification degree of the multiplier 17 is changed, and the gain is controlled by the fixed limiter value of the limiter circuit 8, whereby the dynamic range is increased. To control. Finally, the edge enhancement circuit 9 performs edge enhancement processing.

Next, the output from the analog image processing circuit 4 is digitized by the A / D converter 10, and the output is D
It is input to an SC (digital scan converter) 11, converted into a display coordinate system, converted into an analog form, and then displayed on a television monitor 12 as a tomographic image of the subject.

Here, the operation panel 13 is provided with operation keys necessary for driving the entire apparatus. Especially, in this embodiment, a gain control signal for adjusting the DC level in the detection circuit 6 is provided. Slide potentiometers 14 and 16 for steplessly adjusting A and the dynamic range control signal B for changing the amplification degree of the multiplier 17 are provided. In the present embodiment, the gain control signal A and the dynamic range control signal B are adjusted by the slide volume, but in addition to this, an encoder or the like that can be adjusted steplessly or in multiple steps is used. Alternatively, a plurality of them may be used in combination so that the depth can be adjusted according to the depth of the diagnosis site.

As described above, according to this embodiment,
A slide volume 14 provided on the operation panel 13,
The operator can adjust 16 infinitely while looking at the image displayed on the television monitor 12 to freely set the dynamic range to be displayed, among the reflected signals of the ultrasonic waves received by the probe 1. it can.

[0022]

As described above, in the ultrasonic tomography apparatus according to the present invention, the operator can adjust the encoder, the slide volume, etc. provided on the operation panel,
Since the dynamic range of the image can be set steplessly,
With an extremely simple operation, the operator himself can
With respect to images of the abdomen or peripheral blood vessels, it is possible to obtain the optimum image quality corresponding to each.

[Brief description of drawings]

FIG. 1 is a block diagram of a circuit system of an ultrasonic tomography apparatus according to the present invention.

FIG. 2 is a graph showing a dynamic range of a display image.

FIG. 3 is a block diagram of a circuit system of a conventional ultrasonic tomography apparatus.

FIG. 4 is a diagram illustrating conventional dynamic range control.

[Explanation of symbols]

1 Probe 2 Wave Sending Circuit 3 Wave Receiving Phaser 4 Analog Image Processing Circuit 5 Logarithmic Compression Circuit 6 Detection Circuit 7 Amplifying Circuit (Op Amp) 8 Limiter Circuit 9 Edge Enhancement Circuit 10 A / D Converter 11 DSC (Digital Scan) 12) TV monitor 13 Operation panel 14 Gain control slide volume 15 Dynamic range control operation key 16 Dynamic range control slide volume 17 Multiplier A Gain control signal B Dynamic range control signal

Claims (2)

[Claims] 1. An ultrasonic tomographic apparatus for controlling a probe to transmit / receive ultrasonic waves into / from a subject, wherein the dynamic range is continuously switched with respect to the reflected signal of the ultrasonic wave received by the probe. An ultrasonic tomography apparatus, characterized in that it is provided with a means for adjusting. 2. The ultrasonic tomography apparatus according to claim 1, wherein a multiplier is used for switching the dynamic range.