JPH09168538A - Ultrasonic endoscopic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent induced noise of a cable for an ultrasonic probe received from a closely paralleled cable for an image-element-drive-signal or for a high- frequency knife and to eliminate consequent artifacts of an ultrasonic image. SOLUTION: This ultrasonic endoscopic equipment consists of an ultrasonic probe, which is inserted into a cavity or a position of a live examinee to collect ultrasonic tomography images, and an insulation transformer at a position of the signal route between the ultrasonic probe and a signal transmission circuit. An insulation transformer 7 consists of a primary electrostatic shield layer 16 to electrostatically shield a primary coil 8-1, which is connected to a signal-transmission circuit 13-1, and a secondary electrostatic shield layer 17 to electrostatically shield a secondary coil 9-1, which is connected to an ultrasonic vibrator 11. The primary electrostatic shield layer 16 is connected to a terminal of the normal electric power side, and the secondary electric shield layer 17 is connected to a terminal of the secondary coil 9-1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic endoscopic apparatus, and more particularly to an ultrasonic endoscopic apparatus capable of suppressing induction noise while maintaining leakage current performance and obtaining a high-quality ultrasonic image. .

[0002]

2. Description of the Related Art In recent years, electromagnetic wave noise radiated from electronic devices has caused problems such as malfunction of other electronic devices, fluctuation of measuring instrument data, and noise in monitor images. For this reason, in various countries, in order to prevent other electronic devices from malfunctioning due to electromagnetic noise emitted from the electronic devices, EMC (Electromagne
As a tic compatibility regulation, a legal regulation on the electric field strength of unnecessary electromagnetic waves emitted from electronic devices has started.

On the other hand, an endoscope apparatus for observing the inside of a body cavity is replaced with a conventional fiberscope, and an electronic image pickup device such as a CCD mounted on the distal end portion of the endoscope converts image information into an electric signal for monitoring. Electronic endoscopes displayed on the screen have become the mainstream. Furthermore, an ultrasonic endoscopic apparatus for the purpose of inserting an ultrasonic probe into a living body through a forceps hole of an endoscope and collecting an ultrasonic tomographic image from the inside of the living body is becoming popular.

Since this ultrasonic endoscope apparatus is a device used in a living body, the patient leakage current is severely restricted by the JIS medical safety standards and the like. Therefore, as shown in FIG. 6, the probe portion provided with the ultrasonic transducer has a structure in which it is insulated from the transmission / reception circuit by a pulse transformer or the like and floated. Normally, a pulse transformer mechanically performs a radial scan of an ultrasonic transducer, so
The structure of the rotary transformer is adopted so that the secondary side and the secondary side can rotate at the scanning speed mutually.

Since the vibrator used in the ultrasonic endoscopic probe is made of a low-capacity ceramic or polymer piezoelectric material, the impedance seen from the device side to the probe side is high, and in vivo Since a weak signal reflected from is handled, it is likely to receive external noise. Therefore, a coaxial cable or a shielded wire has been used for connecting the secondary side of the rotary transformer and the ultrasonic transducer.

Further, in the above-mentioned conventional ultrasonic endoscope apparatus, the cable for the image pickup device drive signal, which is a high-frequency clock signal, is arranged in parallel with the forceps hole through which the cable for the ultrasonic probe is inserted. . Further, in addition to the ultrasonic endoscope, a high-frequency scalpel may be used for excision of an affected area or hemostasis.

[0007]

However, in the above-mentioned conventional ultrasonic endoscope probe, since the primary side and the secondary side are insulated from each other in the portion of the pulse transformer, the secondary side of the pulse transformer is It will float above the ground of the ultrasonic diagnostic equipment, and noise will also enter the shield itself,
If a stationary external noise such as a high frequency clock is picked up, stripe artifacts (pseudo images) are generated on the ultrasonic image, which hinders diagnosis.

The image pickup device drive signal is a high frequency clock signal, and the high frequency knife is also supplied with high frequency power. Therefore, as shown in FIG. 5, due to the induction of these high-frequency signals, they are picked up as noise by the ultrasonic probe having high detection sensitivity, and an artifact (pseudo image) is generated in the ultrasonic image, which hinders diagnosis. There was a problem.

In view of the above problems, an object of the present invention is to prevent inductive noise received by a cable of an ultrasonic probe from an image pickup device drive signal cable and a high frequency female cable which are in close proximity to each other. It is an object of the present invention to provide an ultrasonic endoscopic device in which the artifacts of 1. are removed.

[0010]

In order to solve the above problems, the present invention has the following arrangement. That is, the invention according to claim 1 includes an ultrasonic probe which is inserted into a body cavity or a living body to collect an ultrasonic tomographic image from the inside of the living body, and an insulating transformer which is interposed in a signal path between the ultrasonic probe and the transmission / reception circuit. In the provided ultrasonic endoscope apparatus, the insulation transformer includes a first electrostatic shield layer that electrostatically shields a primary coil connected to the transmission / reception circuit, and a secondary coil connected to the ultrasonic probe. And a second electrostatic shield layer that electrostatically shields the first electrostatic shield layer, the first electrostatic shield layer being connected to a reference voltage side terminal of the primary coil, and the second electrostatic shield layer being The ultrasonic endoscope apparatus is characterized in that it is connected to one end of a secondary coil.

According to a second aspect of the present invention, in the ultrasonic endoscope apparatus according to the first aspect, the insulating transformer is
The main point is that it is a rotary transformer.

According to a third aspect of the present invention, in the ultrasonic endoscope apparatus according to the first or second aspect, the first and second electrostatic shield layers are mutually interposed by a dielectric material. The point is that they are insulated.

With the above-described structure, the ultrasonic endoscope apparatus of the present invention is equivalent to that the primary side and the secondary side of the insulating transformer are grounded to a common ground in terms of high frequency, and the entire ultrasonic probe is used. It is possible to stabilize the ground potential of and to prevent high frequency noise from the image sensor drive signal cable, the high frequency female cable, and the like.

Further, by interposing a dielectric material between the first and second electrostatic shield layers, the electrostatic capacitance formed between the primary side and the secondary side of the insulating transformer is the dielectric of the dielectric. As the distance between shields and the area are the same, the capacitance increases as the permittivity increases. When the electrostatic capacitance becomes large, the frequency band in which the ground potential between the primary side and the secondary side can be equivalently shared can be expanded to a low band (the cutoff frequency can be lowered), and a wider frequency band can be obtained. In, a stable ground can be supplied.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part showing a first embodiment of an ultrasonic endoscope apparatus according to the present invention, showing a small-diameter ultrasonic probe provided with a flat plate opposed rotary transformer. In the following drawings including FIG. 1, the dimensional ratio of each part is not constant and is partially exaggerated in order to explain the configuration of the invention.

In FIG. 1, a small-diameter ultrasonic probe which is inserted into a body cavity through an endoscopic forceps hole and collects an ultrasonic tomographic image from the body cavity includes a hand operation section 1, a guiding center section 2, and an insertion section 3.
Consists of A drive shaft 6 supported by a bearing 5 protrudes leftward from a drive device 4 arranged on the right side of the hand-held operation unit 1, loosely penetrates a stator 8 of a rotary transformer 7, and a rotor 9 is fitted therein. . Further, the drive shaft 6 is axially supported by the bearing 5 and is fixed at one end thereof to one end of a flexible and long rotation transmission member 10.

An ultrasonic transducer 11 is provided at the other end of the rotation transmitting member 10 so that the ultrasonic transducer 11 can be radially scanned by the rotational force of the driving device 4. The ultrasonic transducer 11 and the rotation transmitting member 10 are covered with an outer coating 12 having flexibility and insulation, so that contact between the living body and the rotating portion is prevented. The space between the ultrasonic transducer 11 and the outer coating 12 is filled with an acoustic transmission medium (not shown).

The rotary transformer 7 is a flat plate type rotary transformer. Each of the rotary transformers 7 is made of ferrite and is formed into a disk shape. , The stator 8 and the rotor 9 are provided with grooves 8 on each of the facing magnetic coupling surfaces.
-1, 9-1 are provided, and coils 8-2, 9-2 are formed by wire rods having insulating coatings in the grooves 8-1, 9-1, respectively.
Is wound once or several times.

A drive pulse signal is supplied from the ultrasonic diagnostic apparatus 13 to the stator 8 via the external signal line 14.
The drive pulse signal transmitted to the rotor 9 by the magnetic coupling of the rotary transformer 7 causes the ultrasonic transducer 11 to generate an ultrasonic wave through the internal signal line 15 wired in the rotation transmitting member 10. The reflected wave of the ultrasonic wave from the living body is converted into an electric signal by the ultrasonic vibrator 11, and is input to the ultrasonic diagnostic apparatus main body 13 via a route opposite to the drive pulse signal, and an ultrasonic image is formed.

The stator 8 and the rotor 9 of the rotary transformer 7 have a thickness of several μm, though not particularly limited, because electrostatic shield layers are formed on the surfaces of the stator 8 and the rotor 9 which face each other.
The electrostatic shield films 16 and 17 having a thickness of several tens of μm are attached. The electrostatic shield films 16 and 17 are made of a material in which a dielectric layer 18 and a metal layer 19 are laminated. The dielectric material forming the dielectric layer 18 is preferably a dielectric material that can secure a certain level of strength even if it is thin and has a good surface slip property, such as mylar, polyimide, and Teflon. The metal forming the metal layer 19 is preferably copper or aluminum, which has high electric conductivity and rich malleability.

The electrostatic shield films 16 and 17 are attached to the stator 8 and the rotor 9 with their dielectric surfaces facing each other. And coil 8-2 and coil 9-2
The ground side of each is the electrostatic shield film 1
6 and 17 are connected to the metal layer 18.

FIG. 2 is a circuit diagram (a) of a main part of the ultrasonic endoscope apparatus shown in FIG. 1 and its equivalent circuit (b). FIG.
In (a), the transmission / reception circuit 13-1 included in the ultrasonic endoscope apparatus main body 13 and the stator coil 8-1 that is the primary side of the rotary transformer 7 are connected by a coaxial cable 14. The rotor coil 9-1 on the secondary side of the rotary transformer 7 and the ultrasonic transducer 11 are connected by a coaxial cable 15.

The electrostatic shield film 16 of the stator coil 8-1 is connected to the ground side of the stator coil, and the electrostatic shield film 17 of the rotor coil 9-1 is connected to the ground side of the rotor coil. . Since the dielectric layer is provided between the electrostatic shield films 16 and 17, a capacitance 30 shown by a broken line exists between the electrostatic shield films 16 and 17. That is, the rotary transformer 7
Of the primary side and the secondary side of the
Since they are connected by 0, this high frequency equivalent circuit is shown in FIG.

Therefore, the ground potential on the secondary side of the rotary transformer, which is insulated in terms of direct current or alternating current (of the commercial power supply), becomes equipotential to the primary side in terms of high frequency, and is stable with respect to the system ground. Little change due to external noise. In addition, unnecessary electromagnetic waves are not emitted due to fluctuations in the ground potential.

Next, a second embodiment will be described with reference to FIG. The figure is a cross-sectional view of a main part showing a second embodiment of the ultrasonic endoscope apparatus according to the present invention, and shows a small-diameter ultrasonic probe provided with a coaxial cylindrical rotary transformer. In FIG. 3, the same components as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals, and duplicated description will be omitted.

The difference between the second embodiment and the first embodiment is that the shape of the rotary transformer 7 is different. That is, the rotary transformer 7 shown in FIG. 3 is a coaxial cylindrical type, and the rotor 29 and the stator 28 have different shapes. The shapes and the functions of the electrostatic shield films 26 and 27 are different according to the different shapes of the rotary transformers, but the material and function thereof are the same as those of the first embodiment. When the rotary transformer is a cylindrical coaxial type, the inner cylinder may be the rotor and the outer cylinder may be the stator as shown in FIG. 3, but conversely, the inner cylinder may be the stator and the outer cylinder may be the rotor. it can.

In the above embodiments, the rotary probe is used as the insulating transformer for mechanically performing the radial scanning of the ultrasonic probe. However, in an ultrasonic diagnostic apparatus that does not mechanically perform the radial scanning. The present invention can also be applied to a fixed pulse transformer such as a pulse transformer for a circuit board or a screw type embedded pulse transformer.

FIG. 4 is a perspective view and a sectional view of essential parts for explaining an embodiment in which the present invention is applied to an ultrasonic diagnostic apparatus having a fixed pulse transformer as an insulating transformer.

FIG. 4A is a perspective view showing the structure of a pulse transformer using a V-shaped core (or a U-shaped core), and FIG. 4B is a vertical sectional view of the same. . FIG. 4 (a)
At, the primary coil 41 is wound on the left side of the core 40,
The primary-side electrostatic shield layer 42 is provided thereon.
A secondary coil 43 is wound on the right side of the core, and a secondary side electrostatic shield layer 44 is provided thereon. And
The primary side electrostatic shield layer 42 is connected to the reference voltage terminal side 41 a of the primary coil 41 and is connected to the secondary side electrostatic shield layer 44.
Is connected to one terminal 43a of the secondary coil 43.

FIG. 4C is a perspective view showing the structure of a pulse transformer using an EI type core, and FIG. 4D is a sectional view of the same. First, the secondary coil 53 is wound around the center of the E-shaped core 50a, and the secondary side electrostatic shield layer 54, an insulating layer made of a dielectric film (not shown),
The secondary side electrostatic shield layer 52 and the primary coil 51 are sequentially wound, and the I-type core 50b is adhered to form a pulse transformer. Although not shown, the primary side electrostatic shield layer 52 is connected to the reference voltage terminal side of the primary coil 51, and the secondary side electrostatic shield layer 54 is connected to one terminal of the secondary coil 53. ing.

The capacitance between the primary-side electrostatic shield layer and the secondary-side electrostatic shield layer is as shown in FIGS. 4 (a) and 4 (b). The pulse transformer using the EI type core shown in FIGS. 4C and 4D is larger than the pulse transformer using the core), so that the ground level can be stabilized in a wider frequency band. It is preferable in terms.

[0032]

As described above, according to the present invention, the first electrostatic shield layer for electrostatically shielding the primary coil connected to the transmission / reception circuit, and the secondary coil connected to the ultrasonic vibrator. And a second electrostatic shield layer for electrostatically shielding the first electrostatic shield layer connected to the reference voltage side terminal of the primary coil and the second electrostatic shield layer connected to the secondary coil. Since it is connected to one end, the high-frequency ground is shared between the primary side and the secondary side of the insulation transformer without increasing the patient leakage current. There is an effect that it is possible to provide an ultrasonic endoscopic device in which the induced noise received by the cable of the ultrasonic probe is prevented, and the artifacts of the ultrasonic image caused by this are removed.

Further, it is possible to reduce unnecessary electromagnetic waves generated by the ultrasonic probe itself and to prevent interference with other devices.

Further, by interposing a dielectric between the first and second electrostatic shield layers, it is possible to stabilize the ground level in a wider frequency band.

[Brief description of the drawings]

FIG. 1 is a sectional view of essential parts showing a first embodiment (a flat plate opposed rotary transformer) of an ultrasonic diagnostic apparatus according to the present invention.

FIG. 2 is a circuit diagram (a) of an essential part of the first embodiment and an equivalent circuit diagram (b) thereof.

FIG. 3 is a sectional view of essential parts showing a second embodiment (coaxial cylindrical rotary transformer) of the ultrasonic diagnostic apparatus according to the present invention.

4A and 4B are a perspective view and a longitudinal sectional view of a main portion showing another embodiment of the ultrasonic diagnostic apparatus according to the present invention.

FIG. 5 is a diagram illustrating a problem with a conventional ultrasonic endoscope apparatus.

FIG. 6 is a circuit diagram of a main part of a conventional ultrasonic endoscope apparatus.

[Explanation of symbols]

7 Rotary Transformer 8 Stator 8-1 Coil 9 Rotor 9-1 Coil 11 Ultrasonic Transducer 13 Ultrasonic Diagnostic Device Main Body 13-1 Transmitter / Receiver Circuit 14 External Signal Line 15 Internal Signal Line 16, 17 Electrostatic Shield Layer 18 Insulation Layer 19 Metal layer

Claims (3)

[Claims] 1. An ultrasonic wave including an ultrasonic probe that is inserted into a body cavity or a living body to collect an ultrasonic tomographic image from the inside of the living body, and an insulating transformer that is interposed in a signal path between the ultrasonic probe and a transmission / reception circuit. In the endoscope apparatus, the insulation transformer electrostatically shields a first electrostatic shield layer that electrostatically shields a primary coil connected to the transmission / reception circuit and a secondary coil connected to the ultrasonic probe. A second electrostatic shield layer, the first electrostatic shield layer is connected to a reference voltage side terminal of the primary coil, and the second electrostatic shield layer is connected to the second electrostatic shield layer.
An ultrasonic endoscopic device characterized by being connected to one end of a secondary coil. 2. The ultrasonic endoscope apparatus according to claim 1, wherein the insulating transformer is a rotary transformer. 3. The first and second electrostatic shield layers,
The ultrasonic endoscope apparatus according to claim 1, wherein the ultrasonic endoscope apparatuses are insulated from each other through a dielectric material.