JPH0663044A - Intracelom ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To provide an intracelom ultrasonic diagnostic device which is strong against a noise and other disturbance from an electronic endscope and eliminates the remarkable improvement of the device. CONSTITUTION:Noise components generated in both of a coaxial cable 6 for which a vibrator 1 is connected and a dummy coaxial cable 8 for which a dummy vibrator 7 is connected are offset or reduced by a differential amplifier 14 and by a reflected echo signal being a signal component received by the ultrasonic vibrator 1, S/N is improved. Also, by the constitution for which the dummy vibrator 7 and the coaxial cable 8 are added, the improvement of S/N can be realized and the remarkable improvement of the device is not required. In such a manner, an ultrasonic tomographic image whose S/N is satisfactory can be obtained and the diagnostic capability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intracorporeal ultrasonic diagnostic apparatus which is inserted into a body cavity to obtain an ultrasonic diagnostic image in the body and diagnoses the ultrasonic image.

[0002]

2. Description of the Related Art A conventional ultrasonic diagnostic apparatus is shown in FIG.
This will be described with reference to FIG.

Reference numeral 91 is an ultrasonic transducer that emits ultrasonic waves to the subject and receives reflected echoes from the subject. This ultrasonic transducer 91 is provided with a coaxial cable 92.
It is connected to the. The coaxial cable 92 is the limiter circuit 9
3 is connected to the amplifier 94. Then, the amplifier 94 is connected to the observation device 96 via the slip ring 95.
Connected to.

Further, the coaxial cable 92 is connected to the limiter circuit 93, connected to a pulsar 97 via a slip ring 95, and connected to the observation device 96 via the pulsar 97. .

A flexible shaft 98 for transmitting a rotational movement is arranged on the outer circumference of the coaxial cable 92. The flexible shaft 98 is grounded at both ends of the coaxial cable 92, and a blade 99 for lowering the GND impedance is provided on the coaxial cable 9.
The two rear ends are commonly grounded.

Further, the motor 100 transmits the rotary motion to the flexible shaft 98, while the motor 100
The encoder 101 connected to is configured to transmit its rotational position to the observation device 96.

With the above structure, the motor 100 rotates,
The flexible shaft 98, the coaxial cable 92, the vibrator 91, and the head amplifier 102 including the limiter circuit 93 and the amplifier 94 are rotated.

At the same time, the position signal detected by the encoder 101 is transmitted to the observation device 96. Observation position 96
Then, the transmission trigger is transmitted to the pulsar 97 by synchronizing with the position signal. The pulser 97 generates a pulse of several hundred volts. Then, this pulse passes through the slip ring 95 and is applied to the vibrator 91. The oscillator 91 emits an ultrasonic beam according to the applied pulse.

Then, the transducer 91 receives the reflected echo signal returned from the subject. This reflected echo signal is sent to the limiter circuit 93 via the coaxial cable 92, further amplified by the amplifier 94, and transmitted to the observation device 11 via the slip ring 95. In the observation device 96, a radial scan type tomographic image is constructed based on the received reflection echo signal.

The ultrasonic diagnostic apparatus having the above structure is used to obtain a tomographic image by inserting the probe into the body cavity by reducing the diameter of the probe. A probe including the transducer 91 and the coaxial cable 92 is often used by being inserted into a forceps channel of an electronic endoscope, guided into a body cavity, and used.

[0011]

In the apparatus having the above construction, the oscillator 91 and the coaxial cable 92 are inserted along the insertion portion of the electronic endoscope, so that the CCD drive clock of the electronic endoscope is radiated. Then, the clock is the coaxial cable 9
It jumped into 2 and appeared as noise. Blade 9
Even if the capacitive coupling was decreased by 9, no great effect was obtained. In addition, the insertion of the blade 99 increases the diameter of the insertion portion, which makes it impossible to insert the blade 99 into the forceps opening of the electronic endoscope.

As a method of solving the above-mentioned drawback, the scanning of the ultrasonic probe is interrupted when the CCD clock of the electronic endoscope is operating, and the ultrasonic probe is scanned while the CCD clock is interrupted. I have the idea to do However, it has not been realized because of the drawback that the scanning speed is decreased and the apparatus is greatly improved.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ultrasonic diagnostic apparatus that is resistant to noise from an electronic endoscope and other disturbances and does not require a significant improvement of the apparatus. There is.

[0014]

An intracorporeal ultrasonic diagnostic apparatus according to the present invention includes an insertion portion to be inserted into a body cavity, and an ultrasonic transducer provided at the tip of the insertion portion for transmitting and receiving ultrasonic waves. A coaxial cable connected to the ultrasonic transducer, a dummy cable having substantially the same impedance as the coaxial cable, and a differential amplifier circuit that differentially amplifies a signal received by the coaxial cable and the dummy cable. There is.

[0015]

[Operation] According to the configuration of the present invention, noise components generated in both the coaxial cable and the dummy cable due to noise from the electronic endoscope and other disturbances are canceled or reduced by the differential amplifier circuit, S of the signal received by the acoustic transducer
/ N ratio is improved. Further, it is possible to realize the improvement of the S / N ratio only by adding the dummy cable, and it is not necessary to make a great improvement of the device.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 is an overall configuration diagram of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention.

The intracorporeal ultrasonic diagnostic apparatus 20 shown in FIG.
An elongated probe 2 provided with an ultrasonic transducer 1 at its tip, a drive unit 4 that rotationally drives the probe 2, a pulse unit 5 that drives the ultrasonic transducer 1, and an ultrasonic tomographic image are constructed and driven. The observation device 3 for controlling the unit 4 and the pulse unit 5 is provided. The pulse unit 5 is connected to the observation device 3 via a signal line 3a having a connector 5a at its end.
It is connected to the.

The probe 2 includes an ultrasonic oscillator 1, a coaxial cable 6 connected to the ultrasonic oscillator 1, an ultrasonic oscillator 7 as a dummy load, and the ultrasonic oscillator 7.
The dummy coaxial cable 8 is connected to the flexible shaft 9, the flexible shaft 9 and the blade 10.

The ultrasonic oscillator 1 oscillates an ultrasonic wave and receives a reflected echo signal returned from the subject. The ultrasonic oscillator 1 is connected to the non-inverting input terminal of the differential amplifier 12 via the limiter circuit 11 connected to the coaxial cable 6.

The ultrasonic oscillator 7 has the same or substantially the same impedance as the ultrasonic oscillator 1.
Through the limiter circuit 13 connected to the coaxial cable 8,
It is connected to the inverting input terminal of the differential amplifier 12.

The output terminal of the differential amplifier 12 is connected to the ultrasonic diagnostic apparatus 3 via the buffer 14 and the slip ring 15, and further via the pulse unit 5.
The reflected echo signal differentially amplified by the differential amplifier 12 is input to the ultrasonic diagnostic apparatus 3.
The limiter circuits 11 and 13, the differential amplifier 12, and the buffer 14 form a head amplifier 16 in the drive unit 4.

The coaxial cable 6 is connected to the limiter circuit 11 and the slip ring 1 is also connected.
5 is also connected to the pulser 19 in the pulse unit 5. The pulsar 19 is connected to the observation device 3 and generates a drive pulse at the timing of the transmission trigger signal output by the observation device 3. The drive pulse is supplied to the ultrasonic oscillator 1, and the ultrasonic oscillator 1 emits ultrasonic waves.

The motor 17 provided in the drive unit 15 is connected to the probe 2, the head amplifier 16 and the encoder 18, and has a rotatable structure. Further, the encoder 18 is connected to the observation device 3 and outputs the detected rotational position of the motor 17 as a signal.

A flexible shaft 9 which is a rotation transmission mechanism is arranged around the coaxial cables 6 and 8, and a blade 10 is arranged on the outer periphery of the flexible shaft 9. Flexible shaft 9, blade 10
Has its rear end grounded, and the coaxial cables 6 and 8 and the head amplifier 16 are also commonly connected.

The operation of this embodiment will be described. When power is supplied to the motor 17 from the observation device 3, the motor 17
The head amplifier 16 and the probe 2, which are connected to, perform rotational movement.

At the same time, the encoder 18 detects the current rotational position of the vibrator 1 and transmits a position signal to the observation device 3. The observation device 3 synchronizes with the position signal, and the pulsar 19
The transmission trigger signal is output to.

The pulsar 19 generates a drive pulse of hundreds of tens of volts in synchronization with the transmission trigger signal. The drive pulse passes through the slip ring 15 and the coaxial cable 6 and is applied to the vibrator 1. When a high-voltage drive pulse is applied, the vibrator 1 emits an ultrasonic wave, and the echo reflected by the subject returns. The transducer 1 receives the echo, converts it into an electric signal, and transmits it as a reflected echo signal through the coaxial cable 6. The transmitted reflected echo signal passes through the limiter circuit 11 and is input to the non-inverting terminal of the differential amplifier 12.

On the other hand, the vibrator 7 constituting the dummy cable
Does not perform transmission / reception, but picks up only noise (disturbance) on the ultrasonic probe 2. The disturbance includes a CCD driving pulse for the electronic endoscope. This noise is input to the inverting terminal of the differential amplifier 12 through the limiter circuit 13.

The differential amplifier 12 eliminates the disturbance on the coaxial cables 6 and 8 by performing differential amplification, and amplifies only the reflected echo signal received by the vibrator 1. The signal from which the noise is removed passes through the buffer 14 and the slip ring 15, and is transmitted to the observation device 3 via the pulse unit 5.

As described above, the transmission and reception are repeated in synchronization with the rotation of the motor 17, and the tomographic image of the radial scan is displayed on the monitor of the ultrasonic observation apparatus 3.

With the above configuration, noise does not appear even when used in combination with a device such as an electronic endoscope that causes a disturbance, a tomographic image with a good S / N ratio can be obtained, and diagnosis is hindered. It can be used without becoming. Further, the S / N ratio can be improved and realized only by adding the dummy vibrator 7 and the coaxial cable 8 and performing differential amplification, and the apparatus need not be significantly improved.

FIG. 2 is an overall configuration diagram of an ultrasonic diagnostic apparatus according to the second embodiment of the present invention.

The apparatus 50 of the second embodiment shown in FIG. 2 has substantially the same structure as the apparatus of the first embodiment shown in FIG. 1, and only different parts will be described. The other configurations and operations similar to those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

A slip ring 15 is interposed between the coaxial cables 6 and 8 and the head amplifier 16.
The electrical connection is the same as in the first embodiment, and the coaxial cables 6 and 8 are
Are connected to the differential amplifier 12 via limiter circuits 11 and 13 of the head amplifier 16, respectively. The signal differentially amplified by the differential amplifier 12 is sent to the observation device 3 via the buffer 14 and the pulse unit 5. The drive pulse output from the pulser 19 is applied to the vibrator 1 through the head amplifier 16, the slip ring 15, and the coaxial cable 6.

In the above structure, the motor 17 rotates the probe 2 and transmits the position signal of the encoder 18 to the observation device 3. On the other hand, the observation device 3 emits a transmission trigger in synchronization with the position signal, and the pulsar 19 emits a driving pulse in response to the transmission trigger. The drive pulse passes through the head amplifier 16, the slip ring 15, and is guided to the vibrator 1.

In the second embodiment, since the head amplifier 16 can be installed separately from the rotary system such as the motor 17, the influence of noise in the rotary system can be reduced. The rest of the configuration, functions and effects are the same as those of the first embodiment, and the explanation is omitted.

FIG. 3 is a block diagram of an ultrasonic probe according to the third embodiment of the present invention.

The apparatus shown in FIG. 3 has a probe 51 whose dummy load is different from that of the probe shown in FIG. The difference of this probe 51 is that it has a capacitor 52 instead of the dummy vibrator 7. This probe 51 uses a chip-shaped capacitor 52,
The probe 2 can be made smaller than the probe 2 of the first embodiment in which two oscillators are provided. It is also inexpensive. Since the impedances are approximately the same, the noise removal effect is also large.

FIG. 4 is a block diagram of an ultrasonic probe according to the fourth embodiment of the present invention.

The probe 53 shown in FIG. 4 differs from the probe of the third embodiment shown in FIG. 3 in that there is no dummy load and the coaxial cable 8 is open. Other configurations and operations similar to those of the third embodiment are designated by the same reference numerals and description thereof will be omitted.

The fourth embodiment is capable of being further miniaturized as compared with the third embodiment. In addition to being inexpensive,
When a vibrator with high-frequency impedance is used as the vibrator 1, even if the tip of the dummy is opened,
Since the oscillator 1 has almost the same impedance as when it is connected as a load and receives the same level of noise,
The noise removal effect is also great.

FIG. 5 relates to a fifth embodiment of the present invention and shows a mounting structure of the probe tip shown in FIG.

A housing 22 is provided at the tip of the probe shown in FIG. At the rear end of this housing 22,
The flexible shaft 9 is connected. A damper material 23 made of tungsten is disposed at the tip of the housing 22, and the periphery of the damper material 23 is covered with an insulating material 24.

The vibrator 1 is placed on the insulating material 24, and the electrode 25 located between the vibrator 1 and the insulating material 24 is the + side electrode, while the vibrator 1 The electrode 26 on the upper side of is a negative electrode. The electrode 26 is
The housing 22 is connected by a conductive adhesive (hereinafter abbreviated as conductive CE) 27, and the housing 22 and the shield line 28 of the coaxial cable 6 are connected by a conductive CE 27. In this way, the electrode 26 is connected to the shield line 28 and is at the GND potential. On the other hand, the core wire 29 of the coaxial cable 6 is connected to the electrode 25 by the conductive CE 27.

Further, the circumference of the core wire 30 is completely shielded by GND by the housing 22 and the conductive CE 27. Further, the dummy cable 8 is juxtaposed to the coaxial cable 6 with its tip open, and its surroundings are shielded by GND.

In the fifth embodiment, the vibrator 1, which is the load at the tip, is shielded, and noise is less likely to be received from the vibrator 1. As for the portion that receives noise, the proportion of the coaxial cable is higher than that of the vibrator 1. However, in this embodiment, the noise on the coaxial cables 6 and 8 is reduced by taking the differential as described above. Is removed, and an image with a good S / N ratio can be obtained, which is effective for diagnosis.

FIG. 6 relates to a sixth embodiment of the present invention and shows another example of the probe tip mounting structure shown in FIG.

The probe shown in FIG. 6 is different from the probe shown in FIG. 5 in that the dummy end of the coaxial cable 8 is removed and the shield line 31 is grounded to the housing 22 via the conductive CE 27. Is.

By grounding as described above, the impedance at the receiving end and the tip of the coaxial cable, which is more noise resistant than that of the fifth embodiment, is more advantageous.

FIG. 7 is a block diagram of a probe according to a seventh embodiment of the present invention. The probe shown in FIG. 7 differs from the probe of the fourth embodiment shown in FIG. 4 in that the dummy cable 8 is removed and the coaxial cable 6 is replaced by the two-core shielded wire 3
3 is used. The two-core shielded wire 33 connects the vibrator 1 to one of the core wires and opens the other of the core wires on the tip side. The other end of the core wire is used as a dummy, and its rear end is connected in the same manner as the probe of FIG.

In the probe of the sixth embodiment, the probe diameter is smaller than that in which two coaxial cables are provided side by side.
The insertability can be improved and it can be applied to a small body cavity, which is effective for diagnosis.

FIG. 8 relates to an eighth embodiment of the present invention and shows a mounting structure of the probe tip shown in FIG. This embodiment is the sixth
The probe of the embodiment has a two-core shielded wire 33 in place of the coaxial cables 6 and 8, and the other core wire 32 is released while the shielded wire 31 is provided.
Is grounded to the housing 22 through the conductive CE 27. Other configurations and operations similar to those of the sixth embodiment are designated by the same reference numerals, and description thereof will be omitted. The effects of this embodiment are similar to those of the seventh embodiment shown in FIG.

FIG. 9 relates to a ninth embodiment of the present invention, and FIG. 9 is an electric circuit diagram of a head amplifier to which a probe is connected.

First, the outline of the configuration shown in FIG. 9 will be described.
The probe 59 of this embodiment shown in FIG.
And a coaxial cable W1 connected to this oscillator Tr1,
It has a dummy coaxial cable W2 whose one end is released. The head amplifier 54 is connected to the probe 59.

Further, FIG. 9 shows details of the head amplifier 54. A drive pulse from a pulser (not shown) is input to the head amplifier 54. This pulse is supplied to the oscillator T1 of the probe 59 connected to the head amplifier 56 via the diode D3.

The head amplifier 54 differentially removes noise components received by the oscillator Tr1 and the coaxial cable W1 and the dummy coaxial cable W2, and outputs a reflected echo signal having a good S / N ratio. Is. Head amplifier 5
4 is a limiter circuit 55a, 55b, a differential amplifier 56,
And a buffer 57.

The coaxial cable W1 is connected to the limiter circuit 55a via the coupling capacitor C1 and the cathode of the diode D3. On the other hand, the dummy coaxial cable W2 is connected to the limiter circuit 55 via the coupling capacitor C3.
connected to b.

The cathode of the diode D3 is connected to the positive electrode of the oscillator Tr1 via the coaxial cable W2. A resistor R5 whose one end is grounded is connected to the cathode of the diode D3. This resistor R5
Is for stabilizing the potential of the oscillator Tr1.
The capacitor C1 is connected to the limiter circuit 55 in the subsequent stage.
This is for preventing the current flowing from a from flowing through the resistor R5.

A pulser (not shown) is connected to the anode of the diode D3.

The limiter circuit 55a has a resistor R1, one end of which is connected to a power source of voltage V, diodes D1 and D2,
And resistors R2 and R3. In the limiter circuit 55b, a current I (current flowing in the resistor R2) flows from R1 → D1 → R2, and I = (V−0.6) / (2R1−R2). (However,
The voltage drop of the diode D1 is 0.6V). When the cathode side potential of the diode D1 changes, the current I changes, and the current flowing through the resistor R3 also changes.

With the above structure, the cathode potential of the diode D1 appears at the cathode of the diode D2 and transmits a signal. Conversely, when the potential of the cathode of the diode D1 becomes larger than V-2R1 (V-0.6) / (2R1 + R2), the signal is clipped and the diode D2
Is not output to the cathode of. Therefore, the pulser waveform near 100 V is clipped, and the received (reflected echo) signal is transmitted to the differential amplifier 56 in the subsequent stage. Diode D
The signal transmitted to the cathode of 2 is terminated and matched by the resistor R4 having the other end of the capacitor C2 whose one end is grounded.

In this way, the reflected echo signal (received signal) of the oscillator Tr1 is input to the base of the transistor Q1 of the differential amplifier 56.

The limiter circuit 55b is composed of a resistor R6, diodes D4 and D5, and resistors R7 and R8, one end of which is connected to the power source of the voltage V via the switching unit 55c. The disturbance (noise) of the coaxial cable W2 is also input to the transistor Q2 via the limiter circuit 55b at the same time as the reflected echo signal of the oscillator Tr1. The switching unit 55c connects the power source of the voltage V to one end of the resistor R6, while it is also grounded by switching.

Here, the point different from the input stage of the reflected echo signal is that the resistor R9 connected to the other end of the capacitor C9 whose one end is grounded is a variable resistor.
By adjusting the terminating resistor R9, the noise received by the coaxial cable W1 and the noise received by the dummy coaxial cable W2 are set to the same level, and the noise of the coaxial cable W2 is transferred to the transistor of the differential amplifier 56 at the next stage. I am inputting to the base of Q2.

A differential amplifier 56 is formed by grounding the emitters of the transistors Q1 and Q2. The differential amplifier 56 includes, in addition to the transistors Q1 and Q2, a transistor Q3, resistors R10 to R19, and capacitors C5 to C7. Transistor Q that forms a buffer 57 by extracting a signal from the collector of transistor Q2
The signal is output by the emitter follower of Q4. The buffer 57 is composed of resistors R20 to R24 and a capacitor C8 in addition to the transistors Q4 and Q5.
From the emitter of the transistor Q5, the observation device 3 is connected via the capacitor C8 and the resistor R24 connected in series.
The reflected echo signal is output to.

The feature of this head amplifier 54 is that the power source applied to the resistor R6 of the limiter circuit 55b can be turned on and off.

The head amplifier 54 of this embodiment is effective in removing noise by differential amplification. This is premised on that the coaxial cable W1 and the coaxial cable W2 carry the same level of noise. For example, when the dummy coaxial cable W2 is separated from the coaxial cable W1 and an attempt is made to catch the noise, the noise may be removed or the noise may be increased. In the device of the present embodiment, in the case as described above, that is, when the noise increases or the noise removal effect is not so great, the dummy reception signal is separated and the reflected echo signal from the oscillator Tr1 is simply amplified. In some cases, noise can be effectively removed in some cases, and the choice is widened.

FIG. 10 relates to a tenth embodiment of the present invention, and FIG. 10 is an electric circuit diagram of a head amplifier to which a probe is connected. The device of the tenth embodiment shown in FIG. 10 has buffers U1 and U2 in addition to the configuration of the differential amplifier 56 of the ninth embodiment shown in FIG. Other configurations and operations similar to those of the ninth embodiment are designated by the same reference numerals, and description thereof will be omitted.

The differential amplifier 56A shown in FIG. 10 has bases of the transistors Q1 and Q2 and limiter circuits 55a and 5a.
The buffers U1 and U2 are provided between the output and the output of 5b. In this embodiment, the input impedance of the transistors Q1 and Q2 can be ignored, and the variable width of the resistor R9 can be widened.

11 and 12 relate to the eleventh embodiment of the present invention. FIG. 11 is a block diagram of a head amplifier of a probe and a driving unit, and FIG. 12 is a signal waveform diagram of the device shown in FIG.

In the device shown in FIG. 11, the limiters 11 and 13 are connected to the probe 59 shown in FIG.
4, connected to the differential amplifier 12 via a variable amplifier 35. The output of the differential amplifier 12 is output to the observing device 3 as a reflected echo signal, and is also input to a gate 36 that constitutes an automatic adjustment circuit unit that minimizes noise. The automatic adjustment circuit unit includes a detection circuit 37, an integration circuit 38, a one-line delay 39, a comparison circuit 40, a controller 41, and a controller 41, in addition to the differential amplifier 12 for inputting the reflected echo signal to the inverting terminal and the gate circuit 36. This is a loop including the variable amplifier 35.

The gate circuit 36 receives the input signal from among the input signals.
It gates the part that is slow in time, cuts it out, and outputs it. As a result, there is almost no signal component, that is, only the portion corresponding to the noise component is obtained. The detection circuit 37 performs full-wave rectification on the output of the gate and outputs it. The integrating circuit 38 integrates the detect signal output from the detecting circuit 37 and converts it into a direct current.

The comparison circuit 40 outputs the output of the integration circuit 38 and
The output of the integrating circuit 38 is compared with the output of the 1-line delay 39 which delays the output. This comparison circuit 38
Is output to the controller 41.

The comparison circuit 40 compares the integrated value of one line before and the present integrated value, and based on the result, the controller 41 changes the gain of the variable amplifier 35 according to the increase or decrease of the noise component. It is supposed to do.

The vibrator Tr1 is supplied with the drive pulse output from the pulsar 12 at the timing of the transmission trigger (Tx trigger).

FIG. 12 shows the operation of the apparatus shown in FIG. 12 (a) and 12 (a ') show the reflected echo signal of the oscillator Tr1. 12B and 12B 'are noise signals from the coaxial cable W2 amplified by the variable amplifier 35, and FIGS. 12C and 12C' are differential outputs of the differential amplifier 12. FIG. 12D shows a gate output obtained by cutting out a signal at a time (a gate period shown in FIG. 12C) in which a distant signal does not return. This cutout is
This is performed by the gate circuit 36. Incidentally, FIG. 12 (a)
The signals shown in (b) and (c) are as shown in FIGS.
This is a signal one line before the signal shown in (c ').

The signal obtained by detecting the gate output signal shown in FIG. 12 (d) by the detection circuit 37 is the detect signal shown in FIG. 12 (e). This detect signal is applied to the integrating circuit 3
The signal of the level of V1 shown in FIG.

Next, from the result of the comparison circuit 40 comparing the noise detection infinity and the integral value V1 for the first time, the controller 41 determines that the noise is reduced, and the noise variable amplifier 35 is changed. And increase the degree of amplification. Then, as shown in FIG. 12 (f '), the integrated value V2
Becomes smaller. Therefore, the variable amplifier 3 is further repeated.
Increase the amplification factor of 5. Then, at some point V1 <V2
The controller 41 reduces the amplification factor of the variable amplifier 35 at this point. That is, the controller 4
1 controls the gain of the variable amplifier 35 so that the integrated value V, which is a noise component, is minimized.

In this embodiment, the controller 41 optimally controls so as to remove noise, so that manual adjustment is unnecessary. Further, in this embodiment, even if the noise component changes, the noise component can be automatically adjusted.

13 and 14 relate to the twelfth embodiment of the present invention, and FIG. 13 is a diagram for explaining the concept of this embodiment,
FIG. 14 is a circuit diagram of a head amplifier to which a probe is connected and a pulser. FIG. 13A is a configuration diagram of a probe in which the matching coil L is loaded on the vibrator Tr. This probe has a vibrator Tr, a coaxial cable W connecting the vibrator Tr, and a coil L connected in parallel to the vibrator Tr via the coaxial cable W. still,
The dummy cable is not shown.

With the above structure, the capacity of the transmission system can be canceled by the coil L, and power can be efficiently sent to the vibrator Tr. Further, in the above configuration, the oscillator Tr
It is effective that the electric charge charged in the oscillator can be discharged through the coil L and can be driven at a half wavelength of the resonance frequency of the oscillator Tr. See FIG. 13 (b). 13B and 13D, the horizontal axis represents the frequency f of the received signal and the vertical axis represents the impedance Z. 13A and 13C, the horizontal axis represents time t and the vertical axis represents the voltage V of the received signal.

However, when the impedance Z is measured,
As shown in FIG. 13B, the self-resonance of the coil L causes self-resonance at a certain arbitrary position, and the impedance changes drastically.

Therefore, when the coil L is removed as shown in FIG. 13B, the impedance becomes stable as shown in FIG. 13C. On the other hand, the pulsar waveform is inferior in efficiency to that of the above configuration because the oscillator Tr is charged with electric charges and is driven only by the rising edge as shown in FIG.

On the other hand, on the other hand, when it is considered that noise is removed by the differential amplifier in the subsequent stage, the coaxial cable W
, And it is necessary to match the impedance of the dummy cable. Therefore, there is a demand that the impedance should not be changed drastically as shown in FIG.

In consideration of the above points, FIG. 14 shows a configuration in which the advantages of both are taken advantage of but no defects are generated.

The apparatus of the twelfth embodiment shown in FIG. 14 has substantially the same structure as the apparatus shown in FIG.
9, a head amplifier 54B, and a pulsar 89. The head amplifier 54B has substantially the same configuration as the head amplifier 54 shown in FIG. 9, and only different points will be described below. In FIG. 14, the head amplifier 54B
The stage after the transistors Q1 and Q2 is represented as a differential amplifier U3. The operation is similar to the configuration of FIG. A resistor R30 is connected in parallel between the dummy coaxial cable W2 and the capacitor C3. Further, one end of the resistor R6 is directly connected to the power source of the voltage V.

On the other hand, the pulsar 89 includes amplifiers U4, U5,
FET (charge effect transistor) Q6, Q7, resistor R3
1, R32, capacitor C4, transformer T1, diode D
7 and an output coil L1. The pulsar 89 inputs the transmission trigger from the observing device to the amplifiers U4 and U5 and supplies the drive pulse to the vibrator Tr1 via the head amplifier 54B.

The coil L1 is connected in parallel to the output of the pulsar 89 to form a discharge system and the output is damped.
The coil L1 which is the output stage of the pulsar 89 and the oscillator Tr1
In between, a diode D6 is connected in reverse direction in parallel with the diode D3 connected in series.

Then, the pulser 89 applies the drive pulse to the oscillator Tr1 through the diodes D3 and D6.
On the other hand, regarding the received signal from the oscillator Tr1, the diodes D3 and D6 have high impedance (the signal is turned off for signals of 0.6 V or less), and the output coil L1 is cut off from the oscillator Tr1. Can be regarded as Therefore, the influence of the output coil L1 cannot be seen from the probe side, and the impedance of the probe including the oscillator Tr1 and the coaxial cable W1 becomes stable.

In the eleventh embodiment, the influence of the output coil L1 can be ignored from the probe side, and the impedances of the oscillator Tr1 and the coaxial cable W1 and the dummy coaxial cable W2 are stable and approximate to each other. The differential effect of differential amplification can be improved. On the other hand, in the present embodiment, the output coil L1 serves to drive the oscillator Tr1 efficiently.

FIG. 15 is a circuit diagram of a head amplifier and a pulser to which a probe according to the thirteenth embodiment of the present invention is connected. The apparatus shown in FIG. 15 has a plurality of output coils and is configured to switch the coils according to the type of probe. Other configurations and operations similar to those of the eleventh embodiment are designated by the same reference numerals, and description thereof will be omitted. Only the different points will be described below.

The output coil L matching the probe composed of the oscillator Tr1 and the coaxial cable W1 is provided on the pulsar side, but the coil L needs to be changed when the oscillator Tr1 changes. Therefore, probe detection U6
Is used to detect the transducer Tr1 of the probe and the coaxial cable W1 and switch the plurality of coils L provided in the pulsar 89A.

The pulsar 89A shown in FIG. 15 has a plurality of, for example, output coils L2 to L4 provided in parallel at the output stage instead of the output coil L1 of the pulsar 89 shown in FIG. The output coils L2 to L4 are switches SW1 to SW1, respectively.
They are connected in parallel via SW3. Switch SW1〜
SW3 is switched by the switch switching circuit 21. This switch switching circuit 21
Is a probe detector U6 provided near the probe.
The coil is selected according to the detection signal of.

In this embodiment, the matching coil L automatically changes even if the probe is changed to a different frequency.
A proper coil is selected, and the vibrator Tr1 can be efficiently driven.

FIG. 16 is a circuit diagram according to the fourteenth embodiment of the present invention. The device shown in FIG. 16 has a filter in addition to the configuration of the device shown in FIG. The noise cut filter 46 has an output coil L1 of the pulsar 89.
And the diodes D3 and D6 of the head amplifier 54B. Other configurations and operations, such as the head amplifier 54B, are the same as those in the twelfth embodiment, and the same reference numerals are given and the description thereof is omitted.

Since the pulsar 89 and the head amplifier are separated from each other, and there is a disturbance from them, as shown by the alternate long and short dash line in FIG. 16, noise may wrap around to the head amplifier side, and the noise countermeasure effect is remarkable. Sometimes it doesn't climb. As a countermeasure against this, in the present embodiment, a noise cut filter 46 is provided at the input end of the drive pulse of the head amplifier 54B so that the disturbance riding between the pulsar 89 and the head amplifier 54B is not spilled to the head amplifier side. Is. In this embodiment, the pulsar 89 and the head amplifier 54B are used.
The disturbance riding between and can be effectively removed.

FIG. 17 is a circuit diagram according to the fifteenth embodiment of the present invention. The head amplifier of the device shown in FIG. 17 inputs a drive pulse to the oscillator Tr1 via an amplifier U10 and a diode D10, and also supplies a drive pulse to a dummy coaxial cable W2 via an amplifier U11 and a diode D11. It is designed to be entered.

In the present embodiment, the drive pulse is input also to the dummy side, the ringing of the pulse generated at the time of transmission is also generated on the dummy side, and differential noise is removed or reduced by the differential. .

18 (a) and 18 (b) are block diagrams of an apparatus according to the sixteenth embodiment of the present invention.

The apparatus shown in FIG. 18 has the same structure and operation as those of the apparatus shown in FIG. The patient circuit of the observation device 3 is connected to the pulse unit 5 via a connection cable 43. Further, the pulse unit 5 is connected to the drive unit 4 and the oscillator 1 via a connection cable 42.

The common GND of the patient circuit is shown in FIG.
As shown in (a), except for the pulse unit 5, a shield structure is adopted to reduce the impedance.

In the device shown in FIG. 18 (a), the impedance reduction in the pulse unit 5 was insufficient. The high impedance has contributed to noise generation in the pulse unit 5. Therefore, in the device of this embodiment shown in FIG. 18B, the casing of the pulse unit 5 has a shield structure to further reduce the impedance and eliminate the cause of noise generation. In addition, the pulse unit 5,
The outermost periphery of the drive unit 4 is insulated from the patient circuit by, for example, a mold.

FIG. 19 is a configuration diagram according to the 16th embodiment of the present invention. The device shown in FIG. 19 includes a patient GND having a shield structure inside a casing 44 accommodating the pulsar 4.
Grounding case 45 is internally provided, and the pulsar 4 serving as a patient circuit and filters FL1 and FL having different characteristics are provided therein.
2 and switches SW5 and SW6 are provided. The reflected echo signal from the oscillator passes through either the filter FL1 or the filter FL2 via the switches SW5 and SW6, and the echo output passing through is input to the observation device 3. There is.

The case 44 and the grounding case 45 are insulated from each other to prevent accidents due to high voltage.

In the above configuration, the grounding case 45 is provided,
The impedance of the patient GND is lowered. Further, the S / N ratio is improved by filters, for example, filters FL1 and FL2 that cut noise of the electronic endoscope.
The housing 44 may be a mold or may be made of metal as long as it can withstand the pressure with the patient circuit, and may be grounded to the ground in the case of metal.

FIG. 20 shows an ultrasonic diagnostic apparatus 60 according to the 17th embodiment of the present invention. FIG. 21 is a waveform diagram for explaining the operation of the device shown in FIG. Ultrasonic diagnostic equipment 60
Is an ultrasonic probe 61, an observation device 62, a CRT 6
3 and 3.

The probe 6 at the tip of the ultrasonic probe 61.
An ultrasonic transducer 65 is provided in the unit 4. The ultrasonic oscillator 65 is connected to a motor 67 via a flexible shaft 66, and the oscillator 67 is connected by the motor 67.
5 is rotationally driven.

Further, the rotation axis of the motor 67 is 1: 1.
The encoder 68 is connected at a rotation ratio of. From the encoder 68, pulse signals of A phase and B phase, which are rotation angle detection signals, are output to the transmission circuit 69.

The ultrasonic transducer 65 is connected to the transmission circuit 69 and the signal separation circuit 71 by a signal line 70 incorporated in the flexible shaft 66 via a slip ring or the like (not shown). An ultrasonic wave reception signal is input to the signal separation circuit 61 via a signal line 70.
The signal separation circuit 71 includes an A / D converter 72 and a memory 7.
3, via the D / A converter 74, is connected to the non-inverting terminal of the differential amplifier 75. Further, the signal separation circuit 71 is connected to the inverting terminal of the differential amplifier 75 via the signal line 76.

The differential amplifier 75 is an A / D converter 77.
It is connected to a digital scanning converter (hereinafter abbreviated as DSC) 78 via. D.
S. The CRT63 is connected to the C78, and the CRT63
D. S. The ultrasonic tomographic image constructed by C78 is displayed.

The above D. S. The C 78 controls the rotation of the motor 67 via the motor / servo circuit 79, and
It also controls the transmission timing.

In the above configuration, the reception signal received by the ultrasonic transducer 65 is input to the signal separation circuit 71 through the signal line 70. As shown in FIG. 21, the signal separation circuit 71 does not output the received signals 80A and 81A when the transmission circuit 69 outputs the drive pulse to the ultrasonic transducer 75 and the ultrasonic transducer 65. Received signal 80
B and 81B are amplified and then separated.

Further, the signal separation circuit 71 is adapted to analyze and compare the frequencies and phases of the noise components of the separated reception signals 80A, 81A and 80B, 81B. Then, the signal separation circuit 71 corrects the reception signals 80B and 81B so as to match the frequencies and phases of the noise components of the reception signals 80A and 81A including the reflected echo signals.

Received signals 80A, 8 including reflected echo signals
1A is converted into a digital signal by the A / D converter 72 and stored in the memory 73. The stored digital signal is converted into an analog signal by the D / A converter 74 at the timing when the signal obtained by correcting the received signals 80B and 81B enters the differential amplifier 75, and is input to the differential amplifier 75. .

The differential amplifier 75 differentially amplifies the two signals, removes external noise components, and then outputs only the reflected echo signal to the A / D converter 77. The reflected echo signal is converted into a digital signal by the A / D converter 77. D.
S. The input signal is converted into a television signal in C78, and an ultrasonic tomographic image with a good S / N ratio is displayed on the CRT 63.

In this embodiment, S from which extraneous noise has been removed
An ultrasonic tomographic image with a good / N ratio can be displayed, and even when used in combination with an electronic endoscope, a better ultrasonic diagnosis can be performed with a clear image.

22 and 23 are operation explanatory diagrams according to the eighteenth embodiment of the present invention. The configuration of the device of this embodiment is the same as that of the seventeenth embodiment, and the illustration and description thereof will be omitted and different operations will be described.

The reception signal received by the ultrasonic transducer 65 is input to the signal separation circuit 71 through the signal line 70. The signal separation circuit 71, after amplifying the received signal,
As shown in FIG. 2, the received signal is the received signal 82 in the diagnostic area.
A and the non-diagnostic area received signal 82B are separated.

The diagnostic area is, as shown in FIG.
It corresponds to the display range 84 of the ultrasonic image 83 of RT63.
The signal separating circuit 71 separates the received signals 82A, 8 separated.
The frequency and phase of the noise component of 2B are analyzed and compared, and the reception signal 82B of the non-diagnosis region is corrected so as to match the frequency and phase of the noise component of the reception signal 82A of the diagnosis region. Further, the received signal 82B is corrected by the signal separation circuit 71 so as to remove the reflected echo signal component.
Other configurations and effects are similar to those of the seventeenth embodiment,
The description is omitted.

FIG. 24 is a block diagram showing a modification of the seventeenth and eighteenth embodiments. Only the different points will be described below.

The apparatus shown in FIG. 24 is the same as the apparatus shown in FIG. 20, except for the signal separation circuit 71, the A / D converters 72 and 77, and the memory 7.
3, instead of the D / A converter 74 and the differential amplifier 77,
It has an amplifier 85, an A / D converter 86, a memory 87, and a subtractor 88.

As shown in FIG. 24, the amplifier circuit 85 is
It is connected to the subtractor 88 via the / D converter 86 and the memory 87. The output of the A / D converter 86 is connected to the subtractor 88. The subtractor 88 uses the D. S. C
It is connected to 78. Other configurations are the same as those in the seventeenth and eighteenth embodiments, and description thereof will be omitted.

In the above structure, the reception signal received by the ultrasonic transducer 65 is input to the amplification circuit 85 through the signal line 70. The amplifier circuit 85 amplifies the received signal and then outputs the signal to the A / D converter 86. In the A / D converter 86, the input signal is converted into a digital signal in time series, so that the two signal components 80A, 81A and 80B, 81B as shown in FIG. 22 or as shown in FIG. It can be separated into two signal components 82A and 82B. Two signals 80A, 80B (or signals 82A, 8
2B), one signal is temporarily stored in the memory 87, and the other signal enters the subtractor 88 at the timing.
At the same time, it is input to the subtractor 88. The subtractor 88 subtracts the two signals, and the subtracted signal is the D.I. S. It is output to C78. The other operations are the same as those in the seventeenth and eighteenth embodiments, and the description thereof will be omitted.

In this modification, the same effect as in the seventeenth and eighteenth embodiments is obtained, and since the subtraction of two signals is performed digitally, the precision of the subtraction process can be improved. In addition, since the D / A converter is unnecessary, the circuit configuration can be simplified.

[0125]

According to the present invention, noise caused by disturbance, for example, noise of the electronic endoscope when the electronic endoscope and the ultrasonic probe are used in combination by the dummy cable and the differential amplification. Even if emitted by the probe,
In addition to the effect of removing noise, there is an effect that an ultrasonic tomographic image having a good S / N ratio can be obtained without requiring a significant improvement of the apparatus, and the diagnostic ability can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an intracavity ultrasonic diagnostic apparatus according to a first embodiment.

FIG. 2 is an overall configuration diagram of an intracavity ultrasonic diagnostic apparatus according to a second embodiment.

FIG. 3 is a configuration diagram of an ultrasonic probe according to a third embodiment.

FIG. 4 is a configuration diagram of an ultrasonic probe according to a fourth embodiment.

FIG. 5 is a view showing a mounting structure of the probe tip shown in FIG. 4 according to a fifth embodiment.

FIG. 6 is a view showing another example of the mounting structure of the probe tip shown in FIG. 4 according to the sixth embodiment.

FIG. 7 is a configuration diagram of a probe according to a seventh embodiment.

FIG. 8 is a diagram showing a mounting structure of the probe tip shown in FIG. 7 according to an eighth embodiment.

FIG. 9 is an electric circuit diagram of a head amplifier to which a probe is connected according to the ninth embodiment.

FIG. 10 is an electric circuit diagram of a head amplifier to which a probe is connected according to the tenth embodiment.

11 and 12 relate to the eleventh embodiment, and FIG. 11 is a block diagram of a head amplifier of a probe and a driving unit.

12 is a waveform diagram of signals of the device shown in FIG.

13 and 14 relate to the twelfth embodiment, and FIG. 13 is a diagram for explaining the concept of the present embodiment.

FIG. 14 is a head amplifier to which a probe is connected,
And pulsar circuit diagram.

FIG. 15 is a circuit diagram of a head amplifier and a pulser to which a probe is connected according to the thirteenth embodiment.

FIG. 16 is a circuit diagram according to a fourteenth embodiment.

FIG. 17 is a circuit diagram according to a fifteenth embodiment.

FIG. 18 (b) is a block diagram of an apparatus according to the sixteenth embodiment.

FIG. 19 is a configuration diagram according to the sixteenth embodiment.

FIG. 20 is a configuration diagram of an ultrasonic diagnostic apparatus according to a seventeenth embodiment.

21 is a waveform diagram for explaining the operation of the device shown in FIG.

22 and 23 relate to the eighteenth embodiment, and FIG. 22 is a waveform diagram for explaining the operation.

FIG. 23 is a diagram of a monitor screen for explaining the operation.

FIG. 24 is a configuration diagram according to a modification of the seventeenth and eighteenth embodiments.

FIG. 25 is a configuration diagram of a conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 1 ... Ultrasonic transducer 2 ... Probe 3 ... Observation apparatus 4 ... Drive unit 5 ... Pulse unit 6 ... Coaxial cable 7 ... Dummy transducer 8 ... Dummy coaxial cable 12 ... Differential amplifier 19 ... Pulsar 20 ... Extracorporeal cavity Sound diagnostic equipment

Claims (1)

[Claims] 1. An insertion portion to be inserted into a body cavity, an ultrasonic transducer provided at a tip portion of the insertion portion for transmitting and receiving ultrasonic waves, a coaxial cable connected to the ultrasonic transducer, An intracorporeal ultrasonic diagnostic apparatus comprising: a dummy cable having substantially the same impedance as a coaxial cable; and a differential amplifier circuit that differentially amplifies signals received by the coaxial cable and the dummy cable.