JPS58175548A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention provides super 1ttIL diagnosis i! [Technical background of the invention and its problems] Figure 1 shows a block diagram of a conventional ultrasonic diagnostic device (d9 = electronic scan ultrasound 2 diagnostic fill). The symbol O shown in the figure is an ultrasound system, which emits ultrasound beams from ultrasound transducers arranged in the subject area, and also shifts the ultrasound transducers that emit two sounds #L one by one. ) It linearly scans the inside of the subject with an ultrasonic beam and receives echoes reflected from the subject's contents.
2 shows balsa, super fR glove 1, 0II
A pulse signal is applied to the sonic vibrator (Ii) to excite the sonic vibrator (06 is a transmitting abrasive circuit), and each ultrasonic vibrator is controlled so that the ultrasonic beam converges on a certain focus. In order to excite with a certain delay time, pulse t2
An excitation signal is output to the ultra-f wave globe 1 after a certain delay time t%.
04 is a receiving delay circuit, and 06 is an adder, which focuses the echo signal received by each ultrasonic transducer using a receiving delay line.
Add 19 received echo signals to each ultra-f transducer t
It is. 6 is a band pass filter with a value of 69.7
The recorder shown by 08 performs log compression and inspection on the echo signal that has passed through the bandpass filter 6 and outputs a video signal.
ILw! For example, a super-1m fault association is displayed.

By the way, with respect to the transmission spectrum shown in Figure 2), the reception spectrum shifts to the lower frequency side as the reflection position of the ultrasonic beam becomes deeper, as shown in M2 diagram (Z?)((')(4). This f'L is due to the fact that the higher the ultrasonic frequency, the greater the in-vivo attenuation of the ultrasonic wave.Also, the degree of in-vivo attenuation of the ultrasonic wave increases when the reflection position of the ultrasound beam is the same. However, it differs depending on the patient. For example, even if the test site is the same, in an obese person, the in-vivo attenuation is greater than in a lean person with a thin fat layer. As a filter, depending on the depth of the area to be examined and the patient's physique, it is necessary to use a filter that is higher than the limit allowed by the α ratio, as shown by the broken line in Figure 2 (vI) 1). It is desirable to set the center frequency of the filter appropriately so that frequency information can be obtained.Moreover, when the area to be examined is deep, the center frequency of the bandpass filter can be set lower to improve the S/LV ratio. 0 Also, when the filter band is widened, the pulse train becomes narrower, mainly improving distance resolution. However, when the band is wide, signals in bands with few signal components are also obtained, so In addition, if the band of the filter is widened on the low frequency side, the echo signal on the low frequency side will have poor resolution, so the filter ratio will deteriorate. However, the bandpass filter 6 in the conventional ultrat[# cutoff vc@ shown in FIG. It is possible to apply a filter using a frequency and a fixed band, but it is not possible to change the center frequency and band according to the depth of the examined part and the type of AT. In the conventional super-diagnosis system, users such as doctors are unable to make accurate diagnoses by observing the correct onset of L9 depending on the patient and the disease. Ta.

[Purpose of the invention]

This invention was made in view of the above circumstances,
It is an object of the present invention to provide a bandpass filter whose center frequency and bandwidth can be varied depending on the part to be examined.

[Summary of the invention]

The outline of the present invention for achieving the above object is to process an echo signal received by an ultrasonic probe and passed through a bandpass filter, and display 2 all 1! [Ultrasonic diagnosis i to display Il! At the same time, a bandpass filter section that can change the center frequency and a
a center frequency adjuster that changes the function of a function generator for varying the center frequency according to the reflection depth of the ultrasonic wave;
It is equipped with an in-band regulator that changes the in-band range and t% mold.

[Embodiment of the Invention] FIGS. 3 and 4 are block diagrams showing an embodiment of the present invention.

As shown in Fig. 3, the ultra t#1 diagnostic device, which is an embodiment of the present invention, differs from the conventional ultrasonic diagnostic device shown in Fig. 1 in terms of center frequency and bandwidth. a width pass filter 12 whose width is variable;
0, which includes a triangular wave generator 9, a center frequency adjuster 10, and a middle band adjuster 11.
.

As shown in FIG. 4, the bandpass filter 12 includes a plurality of unit bandpass filters 12-1. ...12-21
1 Do not connect in series, unit bandpass filter 12-1
In the device shown in FIG. 6, ) 1 pass filter 12-M
The bypass filters 12-1 and 12-4 each include a low-pass filter 12-1# and a field effect transistor FET-TR1, which connects the capacitor 0 and -1111 to ground, as shown in FIG. By changing the internal resistance of the field effect transistor FET-TR1 by changing the gate voltage, it is possible to determine the low frequency range to be cut off), and the p-pass filter 12-IB is , the internal resistance of the capacitor C2 and the field effect transistor FET-TR, whose one end is grounded, is changed by changing the gate voltage to cut off the high iI4#IL.
It is now 15 that can determine the number area. The unit bandpass filter 12-1 includes a low-pass filter 12-IB and bypass filters 12-1 and 4 having a predetermined band centered around a predetermined center frequency.
Triangular wave generator 9Fi, operational amplifier OP1 of WJl, resistors R1, R, second operational amplifier OPl, and capacitor Cs
and a switch y, the second operational amplifier OP3 is
When the switch drive pulse turns the rainbow switch y off, the capacitor C3 is charged with electric charge, and when the switch y is turned on, the electric charge accumulated in the capacitor Cs is discharged, generating a triangular wave. OBEA is an amplifier 111i whose output is inverted by the PIFi resistor R8°R8.

The center Jtd mantissa key unit 10 connects - to the input terminal of the first operational amplifier OP1 and connects the reference voltage V to the other end.
It is equipped with a variable resistor Rs for applying cct, and a variable resistor R4 which connects the voltage to the input terminal of the second operational amplifier OP and applies a reference voltage Vccf to the other end, and the resistance value of the variable resistor R8. [By varying K, the DC level of the output triangular wave can be determined, and by varying the resistance value of variable resistor R4, the slope of the output triangular wave can be determined. There is.

The in-band adjuster 11 is constructed as shown in FIG.
．． . . . 12 - This is a changeover switch for switching each output and inputting it to the receiver 7. In addition, each part other than the above-mentioned configuration in the ultra-ftfL diagnostic device and each device 1Ilt are the same as those in the conventional ultra-tm diagnostic device. Since it is the same as that, detailed explanation will be omitted.

Next, the operation of the above component devices will be explained.O First, the center n□11+ frequency setting of the unit band pass filter 12-1 will be described. It is synchronized with the sound wave emission and the switch SF is turned OFF.
The time elapsed after switching to the F state corresponds to the depth ' from the body surface of the subject to the ultrasonic reflection point. Toe 9, 5th
In the figure, the echo received by the ultra-ta probe 1 at the next time t0 after turning off the switch y is the body surface OL of the subject! The wave reflected by II is a wave, and the switch 1tOF
The echo received by the ultra-ti probe 1 at time t1゜1 after F K l is x cI from the body surface of the subject.
It is a supersonic wave reflected by a, y at. therefore,
The center frequency of the unit bandpass filter for each echo reflected at each depth within the object is the bypass filter 1.
2-1, 4! : Field effect transistor FET-TR1, FET-TR in low-pass filter 12-IB
, which is determined by the gate voltage. Therefore, when the switch SIP''fr is set to OFF, the gate voltage of Maα increases as shown in FIG. sea urchins increased;
When the switch sr f: is turned on, the charge accumulated in the capacitor C1 is discharged, and a triangular wave is generated as a whole, and the center frequency of the filter is determined by each gate voltage value at each point in time (0). In this method, the center frequency changes over time.Furthermore, by changing the resistance value of the variable resistor R4, the slope 1 of the triangular wave is changed as shown in FIG. Rs.
o By changing the resistance value, the DC level shown by k in FIG. 5 can be changed, and by this adjustment, the center frequency can be freely adjusted according to the depth of the area to be examined. In this embodiment, the center frequency 9 temporal change Fi is a straight line, but it goes without saying that it may be an exponential function.

Next, to set the power in the band of the band pass filter 12, switch the band adjuster 11 to obtain the desired band. 9 steps can be taken to connect it to the

Although one embodiment of the present invention has been described above in detail, the present invention is not limited to the above embodiment, and can be implemented with various modifications within the scope of the gist of the invention.

In addition, the unit band passphr in the embodiment l1Ir
, J iJ RCy ilta, but this may be changed to tLc fikl. In that case, the triangular wave generator is LC
It is necessary to use a predetermined function generator that can vary the impedance t RT in the filter.

〔Effect of the invention〕

According to this invention, the center frequency of the bandpass filter can be changed according to the depth of the diagnostic site within the subject, and the range in which the center frequency changes can be changed by simple operation of the variable resistor. , it can also be fine-tuned. Furthermore, the band of the bandpass filter can be widened or narrowed by a simple switching operation. Therefore, for deep parts inside the subject, the center frequency of the bandpass filter should be lowered to extract components with less bio-attenuation, reduce noise components in other regions, and increase the SiW ratio. It is possible to obtain good ultra-f wavelength clarity. In addition, if you raise the center frequency of the bandpass filter for shallow areas, since there are enough high frequency components in the shallow area, you can receive the ^w4'HL component with good resolution, and receive the low frequency components with poor resolution. By reducing the component, a good two-tone [iligRt- can be obtained. Even if they are at the same depth within the subject, the tW characteristics may differ19.If the biological attenuation is low or the reflected echo is strong, the variable range of the center frequency of the bandpass filter should be shifted higher19.
, resolution can be increased and good superconcentration can be obtained. In addition, by changing the band distribution of the reflected echo of the diagnostic site by one band within the band of the bass filter,
Improvements in ψ ratio and resolution can be obtained as shown in FIG. By appropriately varying the center frequency and band of the bandpass filter according to the C1C10 attenuation characteristics, it is possible to obtain a good ultra-tawt for the patient and to perform accurate medical diagnosis.

[Brief explanation of drawings]

1st I! i! A block diagram showing the ultra-fat diagnostic device of Jti, FIG. 2 (4 (b) 9) is an explanatory diagram showing the transmission and reception spectrum of ultrasound, FIG. Figure 5 is an explanatory diagram showing the relationship between the switch state, gate voltage (FET-0N resistance value), and depth of the diagnostic site. ...Triangular wave generator, 10...Center frequency adjuster, 11...Bandwidth adjuster, 12...
Bandpass filter, 12-1.12-s...R
C Dynamic Filter (Unit Band Pass Filter) 0 Filter Figure 3 12-IS /12-1 WON

Claims (1)

[Claims] In an ultrasonic diagnostic apparatus that processes an echo signal that has passed through a band-pass filter after being received by an ultra-f wrinkle group μm and displays an ultrasonic wave w1 on a display 11, a band-pass filter that can change the center frequency is used. a center frequency adjuster that changes the function of a function generator for varying the center frequency according to the reflection depth of the ultra-fl emitted from the ultra-f wave probe; and a mid-band adjuster that changes the mid-band. % to be equipped with
Ultrasound diagnostic equipment for mold.