JPS61103436A - Ultrasonic endoscope 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] The present invention relates to an ultrasonic endoscope apparatus that realizes clear images with little noise.

Technical disadvantages of the invention and its problems] The conventional ultrasonic endoscopic device, as shown in FIG. etc., and transmits the signal transmitted through the signal line 2 connected to the vibrator 1 to the brush contact 3.
．． One end was connected to ground through 4, and the other end was led to a transmission pulse generation circuit 7 through an external reception display device 5 and a diode 6 for noise cut-off.

In an ultrasonic endoscope device using such brush contacts 3 and 4, the received Noise mixes into weak ultrasound signals, which appears as noise when displaying a tomographic image, making the tomographic image unsightly. Some models have a motor housed in the tip and a vibrator attached to its rotating shaft, but they have the same drawbacks as the one shown in Figure 3.

For this reason, there is a conventional example as shown in FIG. 4 that alleviates the -[ writing defect.

That is, a preamplifier 8 is provided on the rotated side shown by the broken line to amplify the ultrasonic signal received by the transducer 1.

Since this amplifier 8 also rotates in synchronization with the rotation of the vibrator 1, a brush contact 9. Brush contact 10°lII for outputting the output signal of the amplifier 8 to the outside: Brush contact 11 for common signal. A brush contact 12 for applying the transmission pulse is required. Note that the noise cutting diode 6 is also provided on the rotating part side. In the ultrasonic endoscope device configured as described above, the received ultrasonic signal is amplified at a glance and then passes through the brush contact 10. Therefore, the noise voltage generated at the brush contact 10 is transferred to the brush contact 3 in FIG. If the noise voltage is equivalent to the noise voltage in Since the current flows through the brush contact 11 installed in the line, the brush noise caused by this DC current causes a problem, which also has the drawback of causing noise to appear in the displayed image.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and provides an ultrasonic mirror device capable of displaying a bright image with low noise without brush noise added to the received ultrasonic signal. The purpose is to

[Summary of the Invention] The present invention is incorporated into the distal end of an endoscope and can be rotated and scanned.
The signal from the ultrasonic transducer is amplified by a preamplifier that rotates in synchronization with this transducer, and the output is transmitted to the outside via a rotary transformer. By configuring a transmission means supplied externally via a rotary transformer,
This is to prevent noise from being generated or mixed in by the brush, and to obtain ultrasonic diagnostic images with an excellent S/N ratio.

[Embodiments of the invention] Hereinafter, the present invention will be specifically explained with reference to the drawings.

FIG. 1 shows a first embodiment of the invention.

In the ultrasonic endoscope device 21 of the first embodiment, an ultrasonic transducer 23 constituting an ultrasonic transidue is disposed at the distal end portion 22 of the endoscope, and the ultrasonic transducer 23 is placed inside the insertion section. The flexible shaft 24 (formed of a spiral tube or the like) inserted through the flexible shaft 24 (specific shape not shown) is rotated and scanned by a rotation driving means such as a motor.

The flexible shaft 24 has a coaxial cable 25 connected at one end to the vibrator 23 in its hollow part.
is inserted through the cable 25, and the other end of this cable 25 is led to the hand-held operating section. Inside this hand control section (Yo Amplifier Unit 2)
6 is installed and rotated integrally with flexible cylinders 1771 and 24.

The other end of the cable 25 connected to the vibrator 23 is connected to the input end of a low noise figure preamplifier 27 in the amplifier unit 26.

The output end of this preamplifier 27 is connected to one end of the rotor coil 29a of the rotary 1 to lance 29 via a low-frequency cut capacitor 28 or a bidirectional high-pass filter (not shown). . One end of the stator coil 29b of the rotary transformer 29 is connected to a high-frequency trap 31 (formed, for example, by a parallel ξ-oscillating circuit of a coil and a capacitor).
is connected to a sine wave oscillator 32 that oscillates at a low frequency sufficiently lower than the operating frequency of the ultrasonic transducer 23 (for example, a frequency of several 10 to several 100 Hz), and this oscillation output is transmitted to the rotary transformer 29 via a high frequency trap 31. The voltage is applied to the stator coil 29b. Also, one end of this stator coil 29b is connected to a reception display device 34 via a high-pass filter 33 formed of a capacitor and a resistor, for example, and the high frequency signal appearing at both ends of this stator coil 29b is transmitted to the reception display device 34. J, which can be transmitted to the side, is turned on. Note that the other end of this stator coil 29b is grounded.

One end of the rotor coil 29a of the rotary transformer 29 is connected via a second high-frequency trap 35 to a rectifier/smoothing circuit 36 composed of a diode and a capacitor, and this smoothed output is connected to the power terminal of the preamplifier 27. It is connected.

Further, the output of the transmission pulse generation circuit 37 is sent to the brush contact 38.
is connected to cable 25 via diode 39, and the common terminal at a3 of amplifier unit 26 is connected to diode 40. It is connected to an external ]mon signal line (return of the transmission pulse generation circuit 37) via a brush contact 41.

-) In Fig. 1, the portion surrounded by a broken line indicates that the portion is rotationally driven by a rotational driving means such as a motor.

The operation of one embodiment configured in this manner will be described below.

The high frequency pulse generated by the transmission pulse generation circuit 37 is transmitted to the brush 38. After 3 diodes, 25 cables
The ultrasonic waves are transmitted and applied to the rotationally driven vibrator 23, and the ultrasonic waves excited by the vibrator 23 are transmitted to the object side.

The ultrasonic wave reflected from the discontinuous boundary surface of the acoustic impedance of the object excites the vibrator 23, and the high-frequency electric signal generated by the piezoelectric vibration is transmitted via the cable 25 to the preamplifier 27. amplified. This amplified high frequency signal is applied to the rotor coil 29a of the 1-Tally 1 Herance 29 through the J: Uni] Nden 1 No. 28 indicated by the dashed arrow. In this case, since it is blocked by the high frequency trap 35, this high frequency vibration does not flow into the rectifying/smoothing circuit 36 side, and attenuation etc. are prevented from occurring. However, [
1 - rotor coil 29 by tally 1 ~ lance 29
The high frequency signal applied to the rotor:1
1. The IC stator coil 2 is inductively coupled to the IC stator coil 2, etc.
9b, and is sent to the receiving display device 34 via the high-pass filter 33, where the ultrasonic tomographic image is displayed on the display screen.

Further, the high frequency signal transmitted to the stator coil 29b is transmitted to a low frequency sine wave oscillator 3 via a high frequency trap 31.
It is prevented from flowing into the second side.

On the other hand, the low-frequency oscillation output of the oscillator 32 passes through the high-frequency trap 31, passes through the rotary transformer 29 (transmitted to the receiving display device 34 side by m + lx by the high-pass filter 33), and is transmitted to the rotor coil 298. Further, it passes through a high frequency trap 35, becomes a DC smoothed by a rectifier/smoothing circuit 36, and is applied to the power supply terminal of the preamplifier 27 to maintain the preamplifier 27 in an operable state. Although the low-frequency signal induced in the rotor coil 29a passes through the rotary transformer 29 in the opposite direction to the high-frequency signal, the capacitor (or high-pass filter) 28 prevents the low-frequency signal from passing and affects the preamplifier 27 side. do not have. In the figure, the flow of high frequency signals (RF) is shown by broken line arrows, and the flow of low frequency signals (AF) is shown by solid line arrows.

In addition, when the transmission pulse is transmitted via the brush 38 or the brush 41, the noise voltage generated by these brushes 38 and 41 is usually less than the forward voltage of the diode.
It is protected by diodes 39 and 40 and does not affect the received signal.

FIG. 2 shows a second embodiment of the present invention.

In this second embodiment, as is widely used in VTRs, etc., the first
0-Tally transformer 51. A rotary transformer 53 provided with a 211-th tally mill lance 52 is used. A low frequency oscillator 32 is connected to the stator coil 51b of the tenth tally transformer 51, and a Wi power terminal of the preamplifier 27 is connected to the rotor coil 51a via a rectifier/smoothing circuit 36.

Further, the 20th Taritransformer 52 is connected to the reception display device 34 on the stator coil 52b side, and is connected to the output end of the preamplifier 27 on the rotor coil 52a side.

The number is the same as in the first embodiment. In this second embodiment, the rotary transformer 10=s 53 is complicated, but one for a VTR can also be used. In this case, the frequency of the oscillator 32 is not limited as narrowly as in the first embodiment. In addition, 1st. If a short ring is interposed between the 20th tally transformer 51 and 52, more sufficient insulation can be achieved.

Incidentally, as the DC power supply to the amplifier 27, the first
Instead of providing the rotor coil 51a and the stator coil 51b at opposing parts of the 0-tally transformer 51, a light emitting element (or light emitting means) and a photovoltaic force means that generates an electromotive force with light such as a solar cell are provided. You can also do that.

Incidentally, the transmission pulse can also be configured to be transmitted via a rotary transformer without using a brush contact.

[Effects of the Invention] According to the present invention, the 111 of the received signal
, Since the signal is transmitted by a rotary transformer without using brush contacts in the path, noise from the brush contacts does not mix into the received signal, =
A good tomographic image of 11-8/N can be obtained. Also, -El
Since the received signal is amplified and then transmitted through the rotary 1 to the lance, the influence of induced noise that is likely to be mixed in when a rotary transformer is used can be reduced. Furthermore, troubles caused by brush noise in the power supply path of the amplifier, which occur when such an if amplifier is used, can also be eliminated.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the main part of the configuration of the electric system in the first embodiment of the present invention, FIG. 2 is a circuit diagram showing the main part of the structure of the electric system in the second embodiment of the invention, and FIG. The figure is a circuit diagram showing the main parts of the electrical system in a conventional example, and FIG. 4 is a circuit diagram showing the main parts of the electrical system in Haku's conventional example. 21... Ultrasonic endoscope device 23... Ultrasonic transducer 24... Flexible shaft 25... Cable 26... Amplifier unit
127... Preamplifier 28... Capacitor 29... Rotary transformer 31.35... High frequency trap 32... Oscillator 33... High pass filter 34
... Reception display device 36 ... Rectification/smoothing circuit 37 ... Transmission pulse generation circuit 38.41 ... Brush contact 39.40 ... Diode 51 ... Rotary transformer

Claims (2)

[Claims] (1) An ultrasonic transducer that is placed at the tip of the endoscope, is rotated and scanned by a hollow flexible shaft, and has a signal line guided through the inside of the flexible shaft; An amplifier unit is disposed in the endoscope's hand control unit into which signals received by the sonic transducer are input, its rotor coil is connected to the output of the amplifier unit, and its stator coil is connected to the reception input terminal of the ultrasound image display device. a rotary transformer connected to the rotary transformer, an oscillator that applies an alternating current signal with a frequency sufficiently lower than the operating frequency of the ultrasonic transducer to the stator coil of the rotary transformer; Rectifier that selectively rectifies
and a smoothing circuit, using the rotary transformer,
An ultrasonic endoscope apparatus comprising a transmission means for supplying power to the amplifier unit and a transmission means for a received signal. (2) The ultrasonic endoscope apparatus according to claim 1, wherein the ultrasonic transducer receives a transmission pulse for ultrasonic emission through a brush contact and a diode.