JPH02289236A - Ultrasonic blood flow imaging device - Google Patents

Abstract

PURPOSE:To realize a TGC function suited for blood flow imaging treatment through relatively simple constitution by providing an index signal output means and a multiplying means to input a multiplying result after an index signal is multiplied by an output signal from a detection part. CONSTITUTION:A probe 2 and an electronic scanning part 3 output an ultrasonic echo signal to a mode B processing part and a phase detecting part 4 of a blood flow imaging processing part, and the electronic scanning part 3 outputs a trigger signal to an index signal output part 10. The phase detecting part 4 detects an ultrasonic echo signal and provides a blood flow Doppler signal to output it to an analogue multiplier 5. An index signal output part 10 starts from fall of a trigger signal and outputs an index signal Aexp (bt), increased in terms of an index with the passage of a time, to an analogue multiplier 5. The analogue multiplier 5 multiplies a blood flow Doppler signal and an index signal and outputs a produce signal. As a result, amplitude is approximately specified regardless of the passage of a time, and a TGC function is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic blood flow imaging device, and more particularly to an ultrasonic blood flow imaging device equipped with a TGC (time gain control) function.

[Prior Art] An example of a conventional ultrasonic blood flow imaging device equipped with a TGC function is shown in FIG.

In this ultrasonic blood flow imaging device 51, the probe 2
And the electronic scanning unit 53 obtains an ultrasonic echo signal, but the ultrasonic echo signal is transmitted to the TGC amplifier 55 whose gain increases as the reception time is slow (the elapsed time after transmission is long).
is amplified.

The ultrasonic echo signal output from the electronic scanning section 53 is output to a B-mode processing section (not shown). The signal is also output to the phase detection section 4 of the illustrated blood flow imaging processing section.

The phase detection unit 4 detects the ultrasound echo signal to obtain a blood flow Doppler signal, and passes the blood flow Doppler signal through a low-pass filter 6.
and output to the color flow mapping calculation section 8 via the buffer 7.

The color flow mapping calculation unit 8 calculates the average velocity V of blood flow.
The 1 variance value σ and the power value P are calculated and output to the image display unit 9.

The image display section 9 performs color flow display on the color monitor based on the average speed V and the like.

Now, FIGS. 4 to 6 show the 7 in the conventional device 51.
00 function is explained.

Ultrasonic echo signals attenuate depending on the distance they pass through the living body, so even if the signals should be at the same level, the level observed will be lower as the signal comes from deeper into the living body. In other words, the input signal level of the TGC amplifier 55 becomes as shown in FIG.

The gain of the TGC amplifier 55 increases as the reception time becomes slower, but this means that signals from deep within the body are amplified with a larger gain, so the relationship between depth and gain is as shown in Figure 5. .

Therefore, the output signal level of the TGC amplifier 55 becomes as shown in FIG. 6, and the attenuation due to depth is compensated for, and the level remains constant regardless of the depth.

[Problems to be Solved by the Invention] In the conventional device 51 described above, the electronic scanning section 53 is provided with the TGC amplifier 55, but the processing is performed at a high frequency and wide band of IMHz to 10 MHz, and the number of channels is extremely large. Therefore, there is a problem that the configuration is complicated.

Furthermore, the characteristics of the TGC amplifier 55 are set to compensate for in-vivo attenuation in B-mode processing, but since the frequency band of blood flow imaging processing is different from the frequency band of B-mode processing, in-vivo attenuation is also different. Therefore, there is a problem that the 700 function is not sufficiently suitable for blood flow imaging processing.

Therefore, an object of the present invention is to provide an ultrasonic blood flow imaging apparatus that realizes 700 functions suitable for blood flow imaging processing with a relatively simple configuration.

[Means for Solving the Problems] The ultrasonic blood flow imaging device of the present invention includes a detection unit that detects an ultrasonic echo signal and a calculation unit that calculates blood flow velocity and the like from the output signal of the detection unit. In an ultrasonic blood flow imaging apparatus, an exponential signal output means outputs an exponential signal that increases exponentially in accordance with the reception time of an ultrasonic echo signal, and a calculation section multiplies the output signal of the detection section by the exponential signal. A feature of the structure is that it is provided with a multiplication means that is manually operated.

[Effect: Ultrasonic echo signals attenuate exponentially with the distance they pass through the living body. In other words, the later the reception time of the ultrasonic echo signal is, the smaller the output signal of the detection section becomes exponentially.

On the other hand, the exponential signal output by the exponential signal output means becomes exponentially larger as the reception time becomes slower, contrary to the ultrasonic echo signal.

Therefore, by multiplying the output signal of the detection section and the above-mentioned index signal by the multiplication means, the attenuation of the above-mentioned quantity j signal can be compensated for.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples shown in the drawings. Note that this invention is not limited to this.

FIG. 1 shows an ultrasonic blood flow imaging apparatus 1 according to an embodiment of the present invention.

The probe 2 and the electronic scanning unit 3 obtain ultrasonic echo signals and output the ultrasonic echo signals to a B-mode processing unit (not shown) and a phase detection unit 4 of the blood flow imaging processing unit (not shown).

Further, the electronic scanning section 3 outputs a trigger signal that is the starting point of the reception time of the ultrasonic echo signal to the index signal output section 10. This trigger signal is illustrated in FIG. 2(a).

The phase detection unit 4 detects the ultrasound echo signal to obtain a blood flow Doppler signal, and converts the blood flow Doppler signal into an analog multiplier 5.
Output to 5. The blood flow Doppler signal is illustrated in FIG. 2(b). As can be understood from the figure, the amplitude decreases exponentially as time t passes.

The exponential signal output unit 10 outputs an exponential signal Δexp[bt] that starts from the falling edge of the trigger signal and increases exponentially as time t passes, to the analog multipliers 5, 5. The exponential signal Aexp[bt] is illustrated in FIG. 2(C). Constants A and b can be set arbitrarily.

The analog multiplier 5.5 multiplies the blood flow Doppler signal and the index signal and outputs a product signal. The product signal is illustrated in FIG. 2(d). As can be understood from the figure, the amplitude remains approximately constant regardless of the passage of time t. That is,
TGC function is obtained.

The product signal is outputted to a color flow mapping calculation unit 8 via a low-pass filter 6 and a buffer 7.

The color flow mapping calculation unit 8 calculates the average velocity V of blood flow.
The 1 variance value σ and the power value P are calculated and output to the image display unit 9.

The image display section 9 performs color flow display on the color monitor based on the average speed V and the like.

In the above ultrasonic blood flow imaging device 1, since the blood flow Doppler signal has a frequency from DC to about 100 kHz and has a narrow band, it is possible to use analog multipliers with very general specifications for the analog multipliers 5, 5. I can do it. Further, two channels are sufficient for the analog multiplier 5.5. Therefore, the configuration becomes simple.

Also, since the exponential signal can be set independently of B mode,
There is an advantage that a TGC function with characteristics optimal for blood flow imaging processing can be obtained.

[Effects of the Invention] According to the ultrasonic blood flow imaging apparatus of the present invention, a TGC function optimal for color flow processing can be obtained with a relatively simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an ultrasonic blood flow imaging device according to an embodiment of the present invention, FIGS. 2(a) to (d) are signal waveform diagrams of each part of the device shown in FIG. 1, and FIG. 3 is a conventional Figure 4 is a block diagram of an example of an ultrasonic blood flow imaging device, Figure 4 is a characteristic diagram of the depth of the observation point and the input signal level of the TGC amplifier, Figure 5
The figure is a correlation diagram of the depth and the gain of the TGC amplifier, and FIG. 6 is a characteristic diagram of the depth and the output signal level of the TGC amplifier. (Explanation of symbols) 1... Ultrasonic blood flow imaging device 3... Electronic scanning section 4... Phase detection section 5... Analog multiplier 8... Color flow mapping calculation section 10... Exponential signal output section.

Claims (1)

[Scope of Claims] 1. An ultrasonic blood flow imaging apparatus comprising a detection unit that detects an ultrasonic echo signal and a calculation unit that calculates blood flow velocity etc. from the output signal of the detection unit, comprising: The present invention is characterized by comprising an exponential signal output means for outputting an exponential signal that increases exponentially in accordance with the reception time of the detection section, and a multiplication means for multiplying the output signal of the detection section by the exponential signal and inputting the signal to the calculation section. Ultrasonic blood flow imaging device.