JP2000271122A - Ultrasonic probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the electrification with static electricity by forming conductive films as the earth potential on the outer surface of an insulating coating constituting at least the outermost layer of a cable connected to an ultrasonic resonator. SOLUTION: The core 30 of a cable 25 is coated with an insulating layer 31, and a shield wire 32 is attached to the outer surface of the insulating layer 31. The shield wire 32 is coated with an insulating coating 33. Conductive films 34, 35 made of carbon coatings, etc., are formed respectively on the outer surfaces of the insulating layer 31 and the insulating coating 33 of the cable 25. Both conductive films 34, 35 are retained as the earth potential, preventing generation of electrostatic noise by the electrification with static electricity in the insulating coating 33 and the insulating layer 31 caused by sliding friction generated in the operation of this ultrasonic probe 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe which is inserted into a body cavity or the like and performs an ultrasonic inspection by rotating an ultrasonic vibrator. The present invention relates to an ultrasonic probe which prevents the ultrasonic probe from being damaged.

[0002]

2. Description of the Related Art There are two types of ultrasonic inspection apparatuses, one in which an ultrasonic signal is transmitted from the outside of the body epidermis to the inside of the body, and the other in which the body is guided into the body cavity so that the diseased part or the like is located close to the inner wall of the body cavity. Some of them are configured to transmit and receive ultrasonic waves. An ultrasonic endoscope is a typical example of an ultrasonic inspection apparatus to be inserted into a body, and an ultrasonic probe having a small diameter is formed separately from the endoscope, and this ultrasonic probe is used for treatment of the endoscope. There is also an ultrasonic probe inserted into the body through an instrument insertion channel as a guide means, that is, an endoscopically inserted ultrasonic probe.

[0003] In any case, in the ultrasonic inspection device inserted into the body cavity, while the ultrasonic transducer is driven to rotate.
Transmit ultrasonic pulse toward the body at every predetermined angle,
There is one configured to perform so-called mechanical radial ultrasonic scanning in which a reflected echo from a tomographic part in the body is acquired. In performing mechanical radial ultrasonic scanning, there is a configuration in which an ultrasonic transducer is rotationally driven by remote control. This operation is generally performed using a control cable. The control cable has a structure in which a flexible shaft is inserted into a flexible sleeve, an ultrasonic vibrator is connected to the distal end of the flexible shaft, and driving means such as a motor is connected to a proximal end. It is. When the flexible shaft is rotationally driven around the axis in the sleeve by the driving means, the rotation is transmitted to the tip, and the ultrasonic vibrator is rotated. A cable is connected to apply a drive signal to the ultrasonic vibrator and take out a reflected echo signal received by the ultrasonic vibrator to the outside. This cable is designed to be connected to the ultrasonic observation device via a rotary connector or the like on the way, and the ultrasonic observation device processes ultrasonic signals from an ultrasonic transmission / reception circuit or a scan converter. A circuit for generating an ultrasonic image and the like are provided.

[0004] Ultrasonic reception signals are extremely weak signals. Therefore, when transmitting these weak ultrasonic reception signals to an ultrasonic observation apparatus, the image quality of an ultrasonic image is extremely low even if a small amount of noise is captured. Significant effects occur. Regardless of an ultrasonic endoscope or an ultrasonic probe inserted transendoscopically, in the case of an electronic endoscope using a solid-state imaging device as an observation means of the endoscope, the insertion portion A cable for transmitting and receiving signals to and from the solid-state imaging device mounted at the end of the device is connected. The solid-state imaging device is driven via this cable, and a video signal from the solid-state imaging device is transmitted to the processor. Therefore, since the cable connected to the solid-state imaging device is inserted into the insertion portion together with the cable connected to the ultrasonic vibrator, signals such as clock pulses transmitted to the solid-state imaging device are transmitted from the ultrasonic vibrator. It may be a noise source for the ultrasonic reception signal. From the above, it is general to take measures against noise by electromagnetically shielding the cable connected to the ultrasonic transducer.

[0005]

When a shielded cable as described above is used as a cable for transmitting an ultrasonic reception signal, the capture of disturbance noise is suppressed. However, even if a shielded cable is used, generation of noise cannot be completely prevented. In particular, compared to mechanical linear scanning performed by moving the ultrasonic transducer linearly, there is a tendency that the degree of noise generation is greater when performing mechanical radial scanning that rotationally drives the ultrasonic transducer. .

In view of the above points, the present inventors have conducted intensive studies and as a result, have found that when rotating an ultrasonic vibrator, electrostatic noise due to static electricity is generated. Was completed. In other words, in order to rotate and drive the ultrasonic vibrator by remote operation, the ultrasonic vibrator is connected to the tip of the flexible shaft, and this flexible shaft is generally formed by winding a metal wire in a tight coil shape. However, the cable is inserted inside the cable, but the cable is inserted with a certain amount of extra length to the flexible shaft to prevent the cable from being disconnected due to excessive pulling force. General. When the flexible shaft is rotated, the cable naturally follows the rotation, but slides with the flexible shaft by an amount corresponding to the extra length of the cable.

[0007] The outermost layer of the cable is an insulating coating,
Static electricity generated by sliding of the cover of the cable, which is an insulator, with the flexible shaft made of metal becomes a noise source for the cable. In other words, the static electricity that has accumulated due to the sliding of the insulating coating on the flexible shaft is discharged at a certain moment, but there is a possibility that the static noise generated at the time of discharging the static electricity is taken in at the time of signal transmission. In addition, the cable is composed of at least a core wire and a shielded wire, but has a structure in which an insulating layer is interposed between the core wire and the shielded wire by inserting the core wire into an insulating tube or the like. Sometimes
When the cable slides on the flexible shaft, a force in the direction of twisting the cable itself acts, so that relative sliding occurs between the shield wire and the insulating layer. Therefore, static electricity is also generated by relative sliding between the shield wire and the insulating layer. However, no countermeasure has been taken against static electricity due to relative sliding between the shield wire and the insulating layer.

The present invention has been made in view of the above points, and an object of the present invention is to prevent static electricity from being accumulated in a cable connected to an ultrasonic vibrator, and to reduce noise caused by the static electricity. To prevent the occurrence of

[0009]

In order to achieve the above-mentioned object, the present invention provides a flexible shaft in which a metal wire is wound in the form of a tight coil in a sleeve, and an ultrasonic vibration is applied to the tip of the flexible shaft. And an ultrasonic probe, wherein the ultrasonic transducer is rotatably driven by rotating the flexible shaft around an axis in the sleeve, and the ultrasonic probe is provided in the flexible shaft. It is characterized in that a cable connected to the vibrator is inserted, and a conductive film having a ground potential is formed on the outer peripheral surface of the insulating coating constituting at least the outermost layer of the cable.

[0010] The cable may include one or more core wires and one or more core wires.
Or, it is composed of a plurality of shielded wires and an insulating layer interposed between these core wires and the shielded wire. It is desirable to provide a conductive film having a ground potential from the viewpoint of preventing generation of static electricity and improving the shielding function. Here, the conductive film can be formed by means of winding a metal foil or coating the surface. For example, by applying carbon coating, a thin conductive film can be easily formed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. Here, as an example of a system for performing an ultrasonic inspection by inserting it into a body cavity, there is one shown in FIG. 1, for example. In the figure, 1 is an ultrasonic probe, 2 is an ultrasonic operation unit, and 3 is a cord detachably connected to an ultrasonic observation device (not shown). The ultrasonic probe 1
For example, it is inserted through a treatment tool insertion channel 6 provided in the insertion section 5 of the endoscope 4, and the ultrasonic operation unit 2 is connected to a treatment tool introduction section 8 provided in the main body operation section 7 of the endoscope 4. It is fixed.

The ultrasonic probe 1 and the ultrasonic operation unit 2 have the configuration shown in FIG. The ultrasonic probe 1 is provided with a distal end cap 11 connected to the distal end of a flexible sleeve 10, and an ultrasonic vibrator 13 mounted on a rotating substrate 12 is disposed in the distal end cap 11. The rotating substrate 12 is provided with a flexible shaft 14 connected thereto.
Has a length substantially corresponding to the total length of The base end of the flexible shaft 14 is connected to the connector 1
The connector 15 protrudes from the base end of the sleeve 10 by a predetermined length.

The ultrasonic operation unit 2 includes a treatment instrument introduction unit 8
And a casing 17 connected to the attaching portion 16. The casing 17 includes a connector 1 for the ultrasonic probe 1.
A rotating shaft 18 to which the connecting member 5 is detachably connected is provided. A pair of pulleys 19 and 20 are mounted on the rotating shaft 18, a motor 22 is connected to one pulley 19 via a transmission belt 21, and an encoder is connected to the other pulley 20 via a transmission belt 23. 24 are connected. Accordingly, when the motor 22 is rotated, the rotation shaft 18 rotates, and this rotation is transmitted to the connector 15, and the flexible shaft 14 rotates around the axis in the sleeve 10, so that the ultrasonic wave mounted on the rotating substrate 12 is Vibrator 13
The ultrasonic transducer 13 is driven to rotate, and each time it rotates by a predetermined angle, an ultrasonic wave is transmitted from the ultrasonic transducer 13 and a reflected echo from the body tissue is received. This is mechanical radial scanning.

Accordingly, a drive signal is input to the ultrasonic transducer 13 at every predetermined angle detected by the encoder 24, and an ultrasonic pulse is transmitted. Further, the reflected echo from the tomographic part of the body tissue is taken into the ultrasonic transducer 13,
This received signal is transmitted to the ultrasonic observation device. For this purpose, a cable 25 is connected to the ultrasonic vibrator 13, and the cable 25 is inserted inside the flexible shaft 14. The base end of the cable 25 is detachably connected to the rotating shaft 18 via the connection connector 15.
Therefore, the rotating shaft 18 functions as a rotation transmission unit and also as a signal transmission path. The rotating shaft 18 is connected to a rotary connector 26, and the rotary connector 2
A cable 27 drawn from the cord 3 is connected to 6. Accordingly, the cable 27 on the cord 3 side is fixed in the rotation direction, is connected to the ultrasonic vibrator 13, and is connected to the cable 25 rotating with the ultrasonic vibrator 13 and the rotary connector 26 so as to be relatively rotatable.

The ultrasonic probe 1 is inserted through a treatment instrument insertion channel 6 of the endoscope 4, and the treatment instrument insertion channel 6 is provided on an insertion portion 5 inserted into a curved path in a body cavity. Therefore, when the ultrasonic probe 1 is guided into the body cavity, the ultrasonic probe 1 follows the treatment instrument insertion channel 6 and bends in an arbitrary direction. Flexible shaft 1
Reference numeral 4 denotes a cable between the inner diameter of the sleeve 10 and the outer diameter of the flexible shaft 14, and the inner diameter of the flexible shaft 14 and the outer diameter of the cable 25. A predetermined diameter difference is provided between them. The total length of the ultrasonic probe 1 is longer than the treatment instrument insertion channel 6, and usually has a length of 2 m or more.

As described above, the flexible shaft 14 is provided with a predetermined extra length in the sleeve 10 so that the flexible shaft 14 can be smoothly rotated. An extra length is provided so that when the ultrasonic probe 1 is operated in a bent state, tension is applied to the cable 25 to prevent a situation such as disconnection. Since the flexible shaft 14 rotates around the axis inside the sleeve 10, the flexible shaft 14 comes into contact with or separates from the inner surface of the sleeve 10 during the rotation, so that the flexible shaft 14 vibrates,
The cable and the cable 25 inserted therein with an extra length slide inside each other.

FIG. 3 shows the structure of the cable 25 inserted into the flexible shaft 14. Cable 25
A core wire 30 is arranged at the center position of the wire, and the periphery of the core wire 30 is covered with an insulating layer 31. A shield wire 32 is attached to the outer peripheral portion of the insulating layer 31 by knitting in a mesh shape or the like.
Is covered with an insulating coating 33. This is the basic configuration of the cable 25. When the core wire 30 and the shield wire 32 are connected to both electrodes of the ultrasonic vibrator 13 made of a piezoelectric element and a predetermined voltage is applied between these electrodes, the ultrasonic wave When transmission is performed and the ultrasonic vibrator 13 vibrates due to the reflected echo, a voltage is generated in the ultrasonic vibrator 13, and this voltage signal is extracted from the core wire 30.

Here, conductive films 34 and 35 made of carbon coating or the like are formed on the outer surface of the insulating layer 31 and the outer surface of the insulating coating 33, respectively. Both of the conductive films 34 and 35 are set to the ground potential. These conductive films 34 and 35 can be formed, for example, by means such as dipping. Therefore, the conductive films 34 and 35 are easily formed as extremely thin films, and the diameter of the cable 25 as a whole does not become particularly large.

On the outer periphery of the insulating layer 31, there is provided a shield wire 32 formed by knitting or the like independently of the insulating layer 31, and the shield wire 32 is formed of metal. . Thus, the conductive film 34 is held such that the shield wire 32 does not directly contact the insulating layer 31 made of an electric insulator. Further, the insulating coating 33 is a flexible shaft 14 in which a metal wire is wound in a tight coil shape.
The conductive film 35 is laminated on the outer periphery of the insulating coating 33 in order to prevent the insulating coating 33 from directly contacting the flexible shaft 14 made of metal because it is inserted into the inside.

When the ultrasonic transducer 13 is rotationally driven to perform mechanical radial scanning, the flexible shaft 14 is rotated around the axis. At this time, the entire ultrasonic probe 1 vibrates. As a result, sliding occurs between the outer peripheral surface of the cable 25 and the inner surface of the flexible shaft 14. However, since the conductive film 35 is formed on the surface of the cable 25,
The sliding is performed between conductors, and the conductive film 35 is kept at the ground potential. Therefore, there is no possibility that static electricity will be stored in either of the two sliding members. Also, since the insulating layer 31 and the shielded wire 32 are not in a fixed relationship but are substantially formed by attaching the shielded wire 32 to the insulating layer 31, when the cable 25 is twisted by the vibration of the cable 25. Then, relative movement occurs between the insulating layer 31 and the shield wire 32, and they slide with each other. However, the conductive film 34 is also formed on the outer surface of the insulating layer 31,
Since this conductive film 34 is also grounded, the shield wire 3
2 can be reliably prevented from generating static electricity due to sliding contact with the insulating layer 31 directly.

Further, a conductive film 3 is formed on the outer surface of the insulating layer 31.
3, and a conductive film 35 is formed on the outer surface of the insulating coating 32. Since the conductive film 35 is fixed between them,
Even if the cable 25 is vibrated or twisted, there is no relative sliding, and no static electricity is generated. As described above, since the core wire 30 is covered by the conductive films 34 and 35 in addition to the shield wire 32, it is possible to more reliably prevent disturbance noise from being taken in.

As a result, the cable 25 inserted into the flexible shaft 14 has a two-layer thin film conductive film 34,
By simply forming 35, that is, without substantially increasing the diameter of the cable 25, it is possible to almost completely prevent noise from being generated in the ultrasonic reflected signal, which is a weak signal transmitted through the cable 25. . Therefore, the S / N ratio when generating the ultrasonic image signal based on the reflected echo signal is improved, and when the ultrasonic image is displayed on the monitor, the image becomes extremely clear, and the inspection and diagnosis can be performed accurately. Can be done.

Here, the cables connected to the ultrasonic vibrator 13 have various structures such as the cable 40 shown in FIG. 4 and the cable 50 shown in FIG. 5 in addition to the cable shown in FIG. Is used. Cable 40 shown in FIG.
Is a core wire 4 connected to two electrodes of the ultrasonic transducer 13.
1a, 41b, and these two core wires 41a, 41b are inserted into the insulating layers 42a, 42b, and these are further inserted into the second insulating layer 43, and the second insulating layer 43
A shield wire 44 is provided on the outer periphery of the second insulating layer 43, and a conductive film 45 is formed on the outer periphery of the second insulating layer 43. Further, an insulating coating 46 is provided on the outer periphery of the shield wire 44, and a conductive film 47 is also laminated on the outer surface of the insulating coating 46. This configuration is used when an ultrasonic transducer having a large surface area is used. That is, the core wires 41a and 41b are connected to both electrodes of the ultrasonic vibrator 13, so that a potential difference generated between both electrodes can be increased. Therefore, in this configuration, the shield wire 44
Indicates an electromagnetic shielding function.

The cable 50 shown in FIG. 5 is a shield-reinforced cable, and is particularly effectively used when used in an environment where large noise is generated. That is, the first insulating layer 52, the first shielded wire 53, the second insulating layer 54, and the second insulating layer 52 are provided outside the core wire 51 provided on the most central side.
Of the first insulation layer 52 and the first shield wire 53, the second insulation layer 54 and the second shield wire 55 And the conductive film 5 on the outside of the insulating coating 56, respectively.
7, 58, 59 are formed. In this case, the core wire 51 and the first shield wire 53 are respectively connected to the ultrasonic vibrator 13.
Are connected to both electrodes. In addition, the second shield wire 55 is for exerting an electromagnetic shield function. Since there is almost no possibility of sliding between the first insulating layer 52 and the first shield line 53, the conductive film 57 may be omitted.

[0025]

According to the present invention, since the conductive film having the ground potential is formed on the outer peripheral surface of the insulating coating on at least the outer peripheral side of the cable, the ultrasonic vibrator can be used without increasing the cable diameter. While improving the electromagnetic shielding function of the connected cable, it can also prevent static electricity from accumulating on the cable itself, thereby significantly reducing the noise of the ultrasonic reflected echo signal, which is a weak signal transmitted via the cable. As a result, there is an effect that an ultrasonic image obtained by processing the ultrasonic reflection signal can be made extremely clear.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an ultrasonic inspection apparatus including an ultrasonic probe according to an embodiment of the present invention.

FIG. 2 is a sectional view of an ultrasonic probe and its ultrasonic operation unit.

FIG. 3 is an explanatory diagram of a configuration of a cable for an ultrasonic probe according to the first embodiment.

FIG. 4 is an explanatory diagram illustrating a configuration of a cable for an ultrasonic probe according to a second embodiment.

FIG. 5 is an explanatory diagram illustrating a configuration of a cable for an ultrasonic probe according to a third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Ultrasonic operation unit 10 Sleeve 11 Tip cap 13 Ultrasonic transducer 14 Flexible shaft 25, 40, 50 Cable 30, 41a, 41
b, 51 core wire 31, 42a, 42b, 43, 52, 54 insulating layer 32, 44, 53, 55 shielded wire 33, 46, 56 insulating coating 34, 35, 45, 47, 57 to 59 conductive film

Claims (3)

[Claims] 1. A flexible shaft in which a metal wire is wound in a tightly coiled state is inserted into a sleeve, and an ultrasonic vibrator is connected to a tip of the flexible shaft and provided.
By rotating the flexible shaft around an axis in the sleeve, in an ultrasonic probe configured to rotationally drive the ultrasonic vibrator, a cable connected to the ultrasonic vibrator is inserted through the flexible shaft. An ultrasonic probe characterized in that a conductive film having a ground potential is formed on an outer peripheral surface of an insulating coating constituting at least an outermost layer of the cable. 2. The cable according to claim 1, wherein the cable includes one or more core wires and one or more core wires.
Or, a structure in which an insulating layer is interposed between the plurality of shielded wires and these core wires and the shielded wires, and a conductive film having a ground potential is provided on the outer peripheral surface of the insulating layer. The ultrasonic probe according to claim 1, wherein 3. The ultrasonic probe according to claim 1, wherein said conductive film is made of carbon coating.