JPH0747026B2 - Ultrasound endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is an articulatory field endoscope that is inserted into the inner space of a human body lumen or a machine tube to perform optical observation of the lumen and ultrasonic inspection of the surroundings. More specifically, the present invention relates to a rotation transmission mechanism of a mechanical scanning type ultrasonic endoscope that rotates an ultrasonic transducer at the tip by using a hollow flexible shaft.

[Prior Art] A mechanical scanning ultrasonic endoscope in which an ultrasonic scanning head and an endoscope tip functional component such as an observation optical system are provided at the tip of an insertion portion has been greatly used in recent years, particularly in the medical field. Is coming. The scanning mechanism of this mechanical scanning ultrasonic endoscope has a structure in which the rotation of the motor provided in the operating section is transmitted to the tip by a flexible shaft that passes through the insertion section, and the vibrator at the tip is rotated. The oscillator is adapted to rotate about an axis along the insertion direction. That is, the cross section perpendicular to the insertion direction is rotationally scanned.

In this mechanical scanning ultrasonic endoscope, a forward-looking observation optical system that optically observes the front in the insertion direction, and an ultrasonic mechanism that rotationally scans the cross section perpendicular to the insertion direction 360 ° without missing a full circumference The following structures can be considered as the structure of the type that has.

It inserts an endoscope tip functional component such as an observation optical system into the center of the insertion part, guides it to the tip end face of the insertion part, and provides a hollow rotary shaft around the tip part, and on one side peripheral surface of this shaft. A vibrator is arranged, and a hollow flexible shaft made of multiple coils capable of passing endoscope tip functional components such as an observation optical system inside is connected to the hollow rotating shaft.
This is a structure in which the rotation of the drive source provided in the operation portion is transmitted to the hollow rotary shaft at the tip by this flexible shaft to perform scanning.

[Problems to be Solved by the Invention] However, in this method, it is necessary to use a hollow flexible shaft having a thickness through which an endoscope tip functional component can be inserted at the center. A hollow flexible shaft made of multiple coils generally uses a tightly wound coil in order to firmly transmit rotation. In a tightly wound coil, when bending, a tensile force is applied to the outside of the bend and a compressive force is applied to the inside of the coil. have. FIG. 4 is a principle diagram of a conventional flexible shaft showing the state. A'when bent is greatly reduced compared to the length A in a natural state where it is not bent.

Even if the diameter is small, the amount of compression inside is not so large even when bent, and there is less risk of buckling, but when the diameter is thick, the amount of compression increases and it buckles. This hollow flexible shaft with a thickness that allows the functional components of the endoscope, such as the reservoir and the observation optical system, to pass through the inside easily buckles when bent, and smooth rotation cannot be obtained. there were.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain smooth and stable rotation transmission even when a thick hollow flexible shaft made of multiple coils is used.

[Means for Solving Problems] The ultrasonic endoscope of the present invention is characterized by an ultrasonic scanning head provided at the distal end of an insertion portion together with a functional component of the endoscope distal end such as an observation optical system, At least one of the flexible shafts, wherein the ultrasonic scanning head and the ultrasonic scanning driving unit are connected to each other by a hollow flexible shaft made of multiple coils, There is a coarse winding part.

[Operation] In the present invention, since the rough winding portion is provided on at least a part of the flexible shaft, the compressive force at the time of bending is absorbed by closing the gap between the wires, and the competition between the wires is reduced, so that the bending is suppressed. Even when it does not buckle, it can transmit smooth and stable rotation.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 is an overall configuration diagram of this embodiment, in which the distal end portion 1 and the bending portion are
2, an insertion section 4 including a flexible tube section 3, a bending operation section 5, an air / water / suction operation section 6, an eyepiece section 7, a channel opening 8, and an operation section 10 including an ultrasonic scanning drive section 9, Is composed of a cable 11 through which an illumination light transmission fiber bundle, an electric cable and the like pass, a light source device (not shown), and a connector section 12 for connecting the ultrasonic observation device.

The eyepiece 7 is not always necessary when an image sensor such as a CCD image pickup device is used in the observation optical system.

FIG. 1 is a detailed side sectional view of the insertion portion of this embodiment.
As shown in FIG. 2 which is an arrow view of FIG. 1 in the central portion, the objective lens 13 of the observation optical system opened at the tip end face, the illumination window 14 of the illumination optical system, the air / water feeding nozzle 15, Endoscope functional components such as the suction port 16 are provided, and are connected to the operation unit side through the central portion of the insertion unit. Around this, there is a hollow rotary shaft 18 supported by a bearing 17, and on its peripheral surface, a vibrator 19 is provided so as to emit an ultrasonic beam perpendicular to the rotary shaft direction, and an ultrasonic scanning head 42 Is formed. The oscillator is preferably a polymer oscillator that does not require a damper material in order to reduce the diameter of the rotating shaft. To the rear end side of the rotary shaft 18, there is connected a hollow flexible shaft 20 made of a multiple coil through which endoscope functional components such as an observation optical system can be passed.
The rear end of 20 is connected to the ultrasonic drive unit 9 of the operation unit 10. The flexible shaft 20 is composed of triple coils, the second coil 21 is a coarse winding and is made of a wire thicker than the cable 22 of the vibrator 19, and the coil is wound in the space between the wires. The cable 22 of the vibrator is inserted along the direction. Further, the coil 21 is wound in a direction in which its diameter shrinks when a rotational force is applied. The innermost first coil 23 is wound in the opposite direction to the second coil 21, and the outer third coil 24 is wound in the same direction as the second coil 21. In addition, the windings are wound by changing the winding pitch, and the first coil 23 is rotated outward by the rotation and the second coil 23 is wound.
The 21 expands or contracts inward and competes with each other to allow solid rotation transmission without play. Further, the third coil 24 fits nicely with the second coil. First and third weight coils 23,2
4 is preferably made of a thinner wire than the coil 21 of the second weight in terms of flexibility.

In the flexible shaft 20 having such a structure, the portion corresponding to the curved portion 2 of the insertion portion 4 is not closely wound even in the first and third heavy coils 23 and 24, and the space between the adjacent strands is not. A rough winding portion 41 having an empty space is formed. The rough winding portion may be provided at a plurality of positions in the portion where the bending of the insertion portion 4 is large, or may be roughly wound over the entire length.

Reference numeral 25 denotes a distal end block a for holding the functional components of the endoscope distal end and the bearing 17, which has an injection port 42 for injecting an oil 36, which will be described later, and is sealed with a sealing screw 43.
Reference numeral 26 denotes a base of the tip portion 1, which is a tip block b that holds a bearing 27 that supports the rotary shaft 18. The tip block b26 is provided with a water injection port 30 for injecting an ultrasonic transmission medium 29 such as degassed water into the balloon 28, and a discharge port 31 for discharging air or degassed water. Reference numeral 32 is a water supply tube connecting the water injection port 30 and the operation unit side, and 33 is a drainage tube connecting the discharge port 31 and the operation unit side.

Reference numeral 34 is an angle detector that detects the rotation of the rotating shaft. A magnetic type or an optical type is preferable.

The circumference of the rotary shaft 18 is filled with oil 36 which communicates with the inner space of a guide tube 35 which guards the flexible shaft 20 and which also serves as an ultrasonic transmission medium. Reference numeral 37 is an aperture window made of a good ultrasonic transmission material that covers the ultrasonic scanning aperture.

Reference numeral 38 is a bending tube of the bending portion 2, and 39 is a bending rubber that covers the bending portion 2. Further, 40 is a wire for bending the bending tube 38 by remote operation of the bending operation section 5.

In the present device having the above-described structure, even when the bending portion 2 is bent and the flexible shaft 20 is bent, buckling occurs because the coarse winding space absorbs the competition of the wires due to the compressive force. Transmits rotation without incident. FIG. 3 is a principle diagram showing this state.

In the above embodiment, a triple shaft is used, and a flexible shaft having a structure in which a vibrator cable is routed in the space of the second coil is used. However, the vibrator cable is separately provided, and only for transmitting the rotational force. Double coil, inside 1
The heavy coil is wound in a direction in which the diameter expands when a rotational force is applied, and the outer second coil is wound in a direction in which the coil is contracted, and at least a part of the coil, for example, a curved part such as a curved part. It is also possible to use a coarsely wound portion located at.

[Effects of the Invention] In the present invention, since the coarse winding portion is provided on at least a part of the hollow flexible shaft made of multiple coils, the compressive force at the time of bending can be absorbed by the gap between the wires, and There is less competition between them, so smooth and stable rotation can be transmitted without buckling during bending, and smooth and stable ultrasonic scanning becomes possible.

[Brief description of drawings]

FIG. 1 is a detailed side sectional view of the insertion portion of this embodiment. FIG. 2 is a view on arrow A of FIG. FIG. 3 is a principle view showing a state of the flexible shaft of this embodiment when it is bent. FIG. 4 is a principle view showing a state in which a conventional flexible shaft is bent. FIG. 5 is an overall configuration diagram of this embodiment. 18 …… Rotary shaft 20 …… Flexible shaft 41 …… Rough winding part

Claims (1)

[Claims] 1. An ultrasonic scanning head provided at the distal end of an insertion portion together with a functional component of an endoscope distal end such as an observation optical system, and an ultrasonic scanning drive portion provided at an operating portion on the near side, A sonic scanning head and the ultrasonic scanning drive section are connected by a hollow flexible shaft made of multiple coils, and at least a part of the flexible shaft is provided with a coarse winding section in which all overlapping layers are coarsely wound. Ultrasound endoscope characterized by.