Insertion device

Abstract

The endoscope (2) as an insertion device comprises: an insertion body (11) that extends along a length axis (a10) and is flexible; a motor (41) disposed in an operating section (20) disposed at the base end of the insertion body (11); a spiral tube (15) disposed at the front end (12) of the insertion body (11); a transmission member (45) inserted into the insertion body (11) and extending outward along the length axis (a10), rotating about the axis by the driving force of the motor (41), and transmitting the rotation to the spiral tube (15); and a detection device (50) that detects the position of a predetermined part of the transmission member (45) along the length axis (a10) of the insertion body (11).

Description

Technical Field

[0001] The present invention relates to an insertion device that uses the driving force of a driving source to rotate a transmission component, thereby rotating a driven component. Background Technology

[0002] Medical endoscopes generally have an insertion section and an operating section located at the base of the insertion section. The insertion section is elongated along its length axis and is inserted into a body cavity. A camera optical system and an illumination optical system, constituting the observation optical system, are located at the front end of the insertion section. When using the endoscope for observation, the front end of the insertion section is inserted towards the area being examined.

[0003] In addition, there is a known endoscope in which a structure is arranged on the outer periphery of the insertion part, the structure is configured to rotate freely about an axis along the length direction of the insertion part, and a spiral protrusion is arranged on the outer peripheral surface of the structure, thereby having an insertion assistance function to assist the insertion of the insertion part into the lumen.

[0004] In an endoscope equipped with this insertion assistance function, for example, the drive source of an electric motor located in the operating section is transmitted to a flexible drive force transmission component, namely a drive shaft, inserted into the insertion section. The drive shaft rotates around its axis by the transmitted drive force, and this rotation is transmitted to the aforementioned structure. The structure receives the rotation of the drive shaft and rotates in both directions around an axis along the length direction of the insertion section. When the spiral protrusion contacts the lumen wall while the structure is rotating, the spiral protrusion moves forward and backward along the lumen wall, or the lumen wall is pulled along the length axis of the insertion section by the spiral protrusion.

[0005] For example, Japanese Patent No. 6165353 discloses an endoscope device with an insertion assistance function, which includes a torque limiting function that stops the rotation of the motor when the drive current of the motor that rotates the structure reaches or exceeds a threshold. Furthermore, in the endoscope device disclosed in Japanese Patent No. 6165353, a detection probe for detecting the bending shape of the insertion part is disposed in the insertion part. The shape of the detection probe is detected by an observation device that is an external device, thereby changing the operation of the aforementioned torque limiting function according to the bending shape of the insertion part.

[0006] However, in the endoscope device disclosed in Japanese Patent No. 6165353, a detection probe needs to be placed inside the insertion part, so the insertion part becomes a large diameter. In addition, an observation device is also required as an external device.

[0007] The present invention was made in view of the above circumstances, and its object is to provide an insertion device that can prevent the insertion part from becoming too large in diameter and can control the bending shape with a simple structure. Summary of the Invention

[0008] Methods for solving problems

[0009] An insertion device according to one aspect of the present invention comprises: a flexible tube extending along a length axis and being flexible; a drive source disposed at the base end of the flexible tube; a driven member disposed at the front end of the flexible tube; a transmission member inserted into the flexible tube, extending outward from the base end of the flexible tube along the length axis of the flexible tube, rotating about the axis by the driving force of the drive source, and transmitting the rotation to the driven member; and a detection device that detects the position of a predetermined portion of the transmission member along the length axis of the flexible tube.

[0010] Another embodiment of the insertion device of the present invention comprises: a flexible tube extending along a length axis and being flexible; a drive source disposed at the base end of the flexible tube; a driven member disposed at the front end of the flexible tube; a transmission member inserted into the flexible tube, extending outward from the base end of the flexible tube along the length axis of the flexible tube, rotating about the axis by the driving force of the drive source, and transmitting the rotation to the driven member; a sheath disposed to cover the outer periphery of the transmission member; and a detection device that detects the relative position of a predetermined portion of the sheath and a predetermined portion of the transmission member along the length axis of the flexible tube. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating an endoscope system according to one aspect of the present invention.

[0012] Figure 2 This diagram illustrates the operating section of the endoscope in an endoscope system.

[0013] Figure 3 This diagram illustrates the drive unit located within the drive source storage section of the operation unit.

[0014] Figure 4A This diagram illustrates the positional relationship between the magnet and the base end face of the driving force bearing part when the flexible tube is in a straight state.

[0015] Figure 4B This diagram illustrates the positional relationship between the magnet and the base end face of the driving force bearing part when the flexible tube is bent.

[0016] Figure 4C It is a diagram illustrating the positional relationship between the magnet and the base end face of the driving force bearing part when the flexible tube is bent to an angle larger than a predetermined angle.

[0017] Figure 4DThis diagram illustrates the positional relationship between the magnets arranged within the multiple detection ranges of the detection device and the base surface of the driving force bearing part.

[0018] Figure 5 This is a diagram illustrating other structural examples of the insertion device. Detailed Implementation

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0020] Furthermore, in the figures used in the following description, the scale may vary for each component in order to make each component identifiable on the drawing. That is, the present invention is not limited to the number of components, shapes, size ratios, and relative positions of the components shown in these figures.

[0021] In this embodiment, the insertion device is Figure 1 The endoscope system 1 shown is an endoscope 2 and a control system 3. The control system 3 has multiple units 4, 5, 6, 7, and 8 that are connected to the endoscope 2.

[0022] In this embodiment, an endoscope 2 is used to describe the insertion device, but the technology can also be applied to catheters, other insertion devices inserted into the living body, etc., instead of the endoscope 2.

[0023] The control system 3 consists of a light source unit 4, a processor 5, a monitor 6, a controller 7, and an input unit 8. The light source unit 4 provides a light source that emits illumination light. The processor 5 processes the images. The monitor 6 displays the images. The controller 7 functions as an actuator and as a decision-making unit. The controller 7, with these functions, controls the entire endoscope system 1.

[0024] In this embodiment, the input unit 8 is a foot switch. The foot switch 8 is equipped with, for example, a forward switch F and a backward switch B. The forward switch F and the backward switch B are indicator units. The signal output from the indicator unit of the foot switch 8 is input to the controller 7. In the controller 7, the drive unit 40, described later, installed on the endoscope 2, is controlled based on the signal output from the indicator unit.

[0025] In addition, the input unit 8 is not limited to a foot switch, but can also be a keyboard, hand switch, etc.

[0026] The controller 7 is not limited to a dedicated device; for example, it can also utilize a general-purpose processing device such as a personal computer equipped with any program.

[0027] Figure 1 , Figure 2The endoscope 2 shown has an insertion section 10, an operating section 20, and a universal cable 30. The insertion section 10 is elongated and inserted into the lumen of the object. The operating section 20 is disposed at the base end of the insertion section 10. The universal cable 30 extends from the operating section 20.

[0028] The endoscope 2 includes a drive unit 40 that extends from the operation section 20 to the insertion section 10. Furthermore, the endoscope 2 is connected to the control system 3 via a universal cable 30.

[0029] An image signal cable 31 and an illumination optical system 32, including an optical fiber bundle, are inserted into the insertion section 10, operation section 20, and universal cable 30 of the endoscope 2. Reference numeral 32a indicates the light guide connector of the illumination optical system 32, and reference numeral 33 indicates the cable 33 extending from the drive unit 40. The image signal cable 31 and the cable 33 are connected to the processor 5 and controller 7 respectively via the light source 4. Alternatively, the cable 33 can be disposed outside the universal cable 30.

[0030] The insertion part 10 has an insertion part body 11 that is elongated relative to the length axis a10, which is the axis in the length direction, and a spiral tube 15. The spiral tube 15 has spiral ribs 16 formed on the outer periphery of the cylindrical member and is disposed on the outer peripheral surface of the front end side of the flexible tube 14. Alternatively, the spiral tube 15 may be configured to be detachable from the insertion part body 11 and formed as an independent structure different from the insertion part 10.

[0031] The insertion body 11 has, in sequence from the front end side, a rigid front end 12, a bent part 13, and a flexible tube 14. The flexible tube 14 is flexible enough to bend along the lumen.

[0032] The operating unit 20 has a grip 21 for the user to hold. The bending part 13, in conjunction with the operation of the knobs 22 and 23 provided on the grip 21, can be bent in directions corresponding to the four directions (up, down, left, and right) in the viewing image displayed on the monitor 6. The structure of the bending part 13 is known, and its detailed description is omitted.

[0033] The bent portion 13 bends downwards or upwards by rotating the first knob 22 clockwise or counterclockwise. On the other hand, the bent portion 13 bends to the right or left by rotating the second knob 23 clockwise or counterclockwise.

[0034] The front end 12 is provided with an observation optics unit (not shown), a cleaning nozzle (not shown), and a channel front opening (not shown). The observation optics unit is connected to the image signal cable 31. Liquid or gas is ejected from the cleaning nozzle. The channel front opening is an opening on the front side of the channel (not shown) for inserting a treatment tool such as pliers.

[0035] Reference numeral 24 is an anti-bending component. The anti-bending component 24 supports the base end of the flexible tube 14 and prevents bending at the boundary between the operating part 20 and the insertion part 10.

[0036] In addition to knobs 22 and 23, the handle 21 is also equipped with switches 25 assigned various indicators. One or more switches 25 are provided. Switches 25 may include not only electrical switches but also mechanical switches such as suction buttons and air / water supply buttons. Reference numeral 26 is the drive source storage section. The drive source storage section 26 is located at a predetermined position on the handle 21. Although not shown in the figure, a channel base opening is provided on the base end side of the drive source storage section 26.

[0037] The spiral tube 15 is located on the outer circumferential surface near the front end of the flexible tube 14, closer to the base end than the bend 13. The spiral tube 15 rotates clockwise or counterclockwise about the length axis a10 of the insertion part 10.

[0038] When the spiral tube 15 is configured to be detachable from the insertion body 11, it is detachably mounted to the aforementioned position of the flexible tube 14 from the front end side of the insertion body 11 via the front end portion 12 and the bend portion 13.

[0039] The driving force of the drive unit 40 is transmitted to the spiral tube 15, the spiral tube 15 rotates relative to the insertion part body 11, and the auxiliary insertion part 10 is inserted or pulled out relative to the lumen.

[0040] Reference Figure 1 , Figure 3 The drive unit 40 will be described.

[0041] The drive unit 40 mainly includes an electric motor (hereinafter referred to as the motor) 41 and a transmission component 45. The motor 41 is the drive source. The output shaft 41a of the motor 41 rotates clockwise and counterclockwise. The driving force of the motor 41 is transmitted to the gear section 42 and the driving force receiving section 44, and then to the transmission component 45. The gear section 42 has at least one gear that meshes with the motor gear 41b fixedly mounted on the output shaft 41a.

[0042] The gear unit 42 and the motor 41 are held by the housing 43. The housing 43 is fixed to a frame (not shown) provided within the drive source storage unit 26.

[0043] The driving force receiving part 44 is a cylindrical component with an axial through hole 44h. Teeth that mesh with the gear of the gear part 42 are provided on the outer peripheral surface of the driving force receiving part 44. The driving force receiving part 44 is a non-moving component. Specifically, the driving force receiving part 44 is disposed within the recess 27c of the partition member 27 fixedly disposed within the holding part 21. The driving force receiving part 44 disposed within the recess 27c is held so as not to slide along the length axis a10, but to rotate clockwise or counterclockwise around the length axis a10. That is, the driving force receiving part 44 rotates within the holding part 21 in a manner that does not change its position in the direction of the length axis a10.

[0044] The transmission component 45 includes a drive shaft 46 and a rotating component 47. The drive shaft 46 is a stranded wire formed by twisting together multiple wires. The drive shaft 46 has predetermined elasticity, flexibility, and torque transmission characteristics. The rotating component 47 is a rigid rod-shaped component.

[0045] The transmission member 45 integrally forms the base end of the drive shaft 46 and the front end of the rotating member 47. In the transmission member 45, the shaft of the drive shaft 46 and the shaft of the rotating member 47 are coaxial.

[0046] The drive shaft 46 is inserted through the flexible tube 14 along the length axis a10 of the insertion part 10. A drive force output part 48 is fixedly provided at the end of the front end side of the drive shaft 46. The drive force output part 48 is connected to the transmission part 17 provided in the spiral tube 15.

[0047] The base end of the drive shaft 46 extends from the base end of the flexible tube 14 along the length axis a10 of the insertion portion 10, passes within the anti-bend member 24 of the operating portion 20, and is guided into the grip portion 21. The rotating member 47 is connected to the drive shaft 46 near the anti-bend member 24 within the grip portion 21.

[0048] like Figure 1 , Figure 4A As shown, the rotating component 47 extends along the length axis a10 within the holding portion 21 of the operating portion 20. The rotating component 47 passes through the axial through hole 44h of the driving force receiving portion 44 and protrudes a predetermined distance L from the base end face 44f of the driving force receiving portion 44 along the length axis a10.

[0049] Figure 4A The designation 47m indicates that the magnet is fixedly mounted on the base end face of the rotating component 47.

[0050] The middle section of the rotating member 47 is the rotation transmission section 47a. The rotation of the driving force receiving section 44 is transmitted from the through hole transmission section 44a, which is provided in the axial through hole 44h, to the rotation transmission section 47a, causing the rotating member 47 to rotate. Moreover, the rotating member 47 is configured to slide freely along the axial direction within the axial through hole 44h of the rotation transmission section 47a.

[0051] A protective sleeve 49 is provided on the outer peripheral surface of the drive shaft 46 to protect the drive shaft 46. The protective sleeve 49 is formed of a resin material that is electrically insulating, wear-resistant, and flexible. The base end of the protective sleeve 49 is fixed to the front end of the anti-bend member 24. The front end of the protective sleeve 49 is fixed to a predetermined position on the front end of the flexible tube 14.

[0052] Reference numeral 50 indicates a detection device. In this embodiment, the detection device 50 is a magnetic sensor 51. The magnetic sensor 51 is fixed to the partition member 27. The magnetic sensor 51 detects whether a magnet 47m moving along the length axis a10 is within the detection range a51 indicated by the dashed line of the magnetic sensor 51. When the magnetic sensor 51 detects the magnet 47m within the detection range a51, it transmits a detection signal to the controller 7 via the signal line 51L.

[0053] In flexible tube 14 Figure 4A In the straight state shown, the magnet 47m is confined within the detection range a51 of the magnetic sensor 51. When the magnet 47m is within the detection range a51, the magnetic sensor 51 outputs a detection signal to the controller 7. The detection sensitivity of the magnetic sensor 51 can be adjusted by changing the size (thickness, etc.) of the magnet 47m.

[0054] Furthermore, in this embodiment, the gear section 42 is a gear system with multiple gears arranged in a specific order. The driving force of the motor 41 is transmitted in the following sequence: motor gear 41b, gear system, driving force receiving section 44, and transmission member 45. By appropriately setting the gear ratio of the multiple gears in the gear system, the transmission member 45 is driven with a specified torque and a specified speed.

[0055] Furthermore, depending on the type of motor 41 and the control method of the motor 41, a gear system may not be required. That is, depending on the type of motor 41 or the control method, a gear system with multiple gears may not be used, and the driving force of the motor 41 may be transmitted to a single gear or directly to the driving force receiving part 44 to drive the transmission part 45.

[0056] The function of the endoscope system 1 shown above will be explained.

[0057] The surgeon inserts the endoscope's insertion body 11 into the lumen through the inlet. During the insertion of the insertion body 11, the surgeon operates the foot switch 8 as needed.

[0058] When the surgeon operates the forward switch F, the controller 7 activates the magnetic sensor 51. During the detection process of the magnet 47m set on the rotating component 47, the magnetic sensor 51 outputs a detection signal to the controller 7. Upon receiving the detection signal from the magnetic sensor 51, the controller 7 determines that motor drive has started and controls the drive motor 41.

[0059] Therefore, the output shaft 41a of the motor 41 rotates in a predetermined direction. This rotation of the output shaft 41a is transmitted from the motor gear 41b to the gear section 42, and from the subsequent gear of the gear train (see reference 41b) in the gear section 42... Figure 3 The denomination 42e) is transmitted to the driving force receiving part 44, which rotates.

[0060] As the driving force receiving part 44 rotates, the rotating part 47 rotates, and the rotating part 47 and the driving shaft 46 rotate. The rotation of the driving shaft 46 is transmitted to the transmission part 17, which is connected to the driving force output part 48 provided on the shaft 46. As a result, the helical tube 15 rotates about the length axis a10 of the insertion part 10 in a predetermined direction.

[0061] As the spiral tube 15 rotates, the rib 16 also rotates about the length axis a10. When the rotating rib 16 contacts the inner wall surface of the lumen, the inner wall surface is pulled towards the base end of the insertion part 10 by the rib 16. In other words, the front end portion 12 of the insertion part 10 moves towards the depth of the lumen.

[0062] As the spiral tube 15 rotates and the insertion part 10 is inserted into the depth of the lumen, the flexible tube 14 of the insertion part body 11 bends along the bending state of the lumen.

[0063] When the flexible tube 14 is in a straight state Figure 4B When the gradual angle change shown is transformed into a bending state, the transmission component 45 is slightly pulled into the flexible tube 14 as indicated by arrow Y4B. At this time, the magnet 47m, which is fixedly mounted on the rotating component 47, also moves from the position shown by the dashed line along the length axis a10 towards the position shown by the solid line on the base end face 44f side of the driving force receiving part 44.

[0064] When the moved magnet 47m is within the detection range a51 of the magnetic sensor 51, the magnetic sensor 51 continuously outputs a detection signal to the controller 7. During the period when the detection signal from the magnetic sensor 51 is input to the controller 7, the controller 7 determines that the bending state of the flexible tube 14 is within the specified range and allows the spiral tube 15 to continue rotating.

[0065] On the other hand, when the flexible tube 14 is as follows Figure 4C As shown Figure 4BWhen the cumulative value of the bending angle of the bent portion exceeds a predetermined value and the bending becomes complex, the transmission component 45 is pulled significantly into the flexible tube 14 as indicated by arrow Y4C. At this time, the magnet 47m moves along the length axis a10 toward the base end face 44f of the driving force bearing part 44 and moves out of the detection range a51 of the magnetic sensor 51, stopping the output of the detection signal from the magnetic sensor 51 to the controller 7.

[0066] When the output of the detection signal from the magnetic sensor 51 to the controller 7 stops, the controller 7, which determines that the motor drive has stopped, switches to control that stops the motor 41.

[0067] In this embodiment, when the magnet 47m, which is fixedly mounted on the rotating component 47 of the transmission component 45 as described above, is pulled along the length axis a10 to the base end face 44f side of the driving force bearing part 44 and detaches from the detection range a51 of the magnetic sensor 51, the controller 7 determines that the cumulative value of the bending angle of the flexible tube 14 exceeds the predetermined value and bends in a complex manner, and activates the torque limiting function to stop the rotation of the spiral tube 15.

[0068] Furthermore, when the surgeon operates the back switch B, the controller 7 prevents the magnetic sensor 51 from activating and instead causes the output shaft 41a of the motor 41 to rotate in the opposite direction to when the forward switch F is operated.

[0069] As described above, the rotation of the output shaft 41a is transmitted from the motor gear 41b to the gear section 42, the subsequent gear 42e of the gear train, the driving force receiving section 44, the rotating component 47, and the drive shaft 46. Moreover, the rotation of the drive shaft 46 is transmitted from the driving force output section 48 to the transmitted section 17 as described above.

[0070] As a result, the spiral tube 15 rotates about the length axis a10 of the insertion part 10 in the opposite direction to when the forward switch F was operated. At this time, the rib 16 also rotates with the spiral tube 15. Furthermore, while the spiral tube 15 is rotating, when the rib 16 is in contact with the inner wall surface of the cavity, the inner wall surface is wrapped around the rib 16 and pulled towards the front end of the insertion part 10. In other words, the front end 12 of the insertion part 10 moves in the opposite direction within the cavity, that is, from the depth towards the entrance of the cavity.

[0071] The endoscope 1, which has a spiral tube 15 disposed on the side of the bend 13 of the flexible tube 14 of the insertion body 11, has a torque limiting function. The torque limiting function is provided with: a magnetic sensor 51, which is fixedly disposed in the holding part 21 of the operation part 20; and a magnet 47m, which is fixedly disposed in the holding part 21 and slides freely along the length axis a10 direction of the transmission member 45.

[0072] With the forward switch F activated, when the magnet 47m is within the detection range a51 of the magnetic sensor 51, the magnetic sensor 51 outputs a detection signal to the controller 7. Upon receiving the detection signal, the controller 7 controls the drive of the motor 41. While the motor 41 is being driven, when the magnet 47m moves out of the detection range a51 of the magnetic sensor 51, the controller stops outputting the detection signal to the controller 7, stops driving the motor 41, and the rotation of the helical tube 15 stops.

[0073] In this embodiment, the torque limiting function of the endoscope 1 is achieved by incorporating a magnetic sensor 51 and a magnet 47m of a transmission member 45 that is fixedly mounted within the holding part 21 of the operating part 20 and slidably moves along the length axis a10. Therefore, it is unnecessary to install a sensor and signal line for the torque limiting function within the insertion part body 11. Consequently, the undesirable situation of the outer diameter of the insertion part body 11 being too large is eliminated. As a result, it is possible to achieve a smaller diameter for the insertion part body 11, which is equipped with the helical tube 15.

[0074] Furthermore, when the bending state of the flexible tube 14 changes, the amount by which the transmission member 45 is pulled in changes. When the controller 7 stops outputting the detection signal because the magnet 47m fixed at the base end is pulled into the flexible tube 14 and disengages from the detection range a51 of the magnetic sensor 51, regardless of the bending shape of the insertion body 11, it determines that the bending state of the flexible tube 14 exceeds the specified range and activates the torque limiting function.

[0075] In other words, when the magnet 47m, which is fixedly installed on the pull-in transmission member 45, is within the detection range a51 of the magnetic sensor 51, regardless of the bending shape of the insertion part body 11, the driving force of the motor 41 is transmitted from the transmission member 45 to the spiral tube 15 to make the spiral tube 15 rotate, thereby maintaining good insertion performance.

[0076] Furthermore, in the above-described embodiment, when the magnet 47m is within the detection range a51 of the magnetic sensor 51, a detection signal is output from the magnetic sensor 51 to the controller 7 to control the motor 41.

[0077] Figure 4D The magnetic sensor 51A shown has multiple detection ranges a1, a2, and a3 along its length axis a10. The magnetic sensor 51A outputs detection signals to the controller 7, which differ according to each detection range a1, a2, and a3. The controller 7 controls the drive current of the motor 41 with a preset current value based on each input detection signal.

[0078] Specifically, when the flexible tube 14 is in a straight state, the magnet 47m, shown by the solid line, is located within the first detection range a1. As described above, when the forward switch F is operated and the magnetic sensor 51A becomes active, a first detection signal is output from the magnetic sensor 51A to the controller 7. Upon receiving the first detection signal, the controller 7 determines that the motor is being driven and supplies a predetermined first drive current to the motor 41 to drive the motor 41.

[0079] When the flexible tube 14 bends, as shown by the dashed line, the magnet 47m moves along the length axis a10 into the second detection range a2. At this time, a second detection signal is output from the magnetic sensor 51A to the controller 7. Upon receiving the second detection signal, the controller 7 determines that the driving force of the motor 41 has changed and supplies a predetermined second driving current to the motor 41 to control the motor 41. The current value of the second driving current is preset to be higher than the current value of the first driving current.

[0080] As the flexible tube 14 bends further, as shown by the double-dotted line, the magnet 47m moves along the length axis a10 into the third detection range a3. At this time, the magnetic sensor 51A outputs a third detection signal to the controller 7. Upon receiving the third detection signal, the controller 7 determines that the driving force of the motor 41 has changed, and supplies the motor 41 with a third driving current that is pre-set to be higher than the second driving current to control the motor 41.

[0081] Furthermore, when the magnet 47m deviates from the third detection range a3 of the magnetic sensor 51A to the base end face 44f side of the driving force bearing part 44, the output of the detection signal from the magnetic sensor 51A to the controller 7 stops. As a result, as described above, the controller 7 switches from controlling the drive of the motor 41 to controlling the motor 41 to stop it.

[0082] The controller 7 receives various detection signals from the magnetic sensor 51A and outputs a predetermined drive current corresponding to the bending state of the flexible tube 14 to the motor 41 to control the motor 41. As a result, regardless of the bending shape of the flexible tube 14, the spiral tube 15 rotates by receiving the optimal drive current matching the bending state of the flexible tube 14, and stops rotating when the bending state exceeds a specified range.

[0083] Furthermore, the detection range of the magnetic sensor 51A is not limited to three locations; it can be three or more locations or two locations. Additionally, the detection device 50 is not limited to the magnetic sensors 51 and 51A; it can also be a transmissive or reflective optical sensor. Furthermore, the detection device 50 is not limited to a non-contact sensor; it can also be a contact switch such as a limit switch with a microswitch.

[0084] like Figure 5As shown, a coil sheath 49c is provided on the outer peripheral surface of the drive shaft 46 instead of a sheath 49. The coil sheath 49c is formed of a non-magnetic body that has wear resistance and elasticity to protect the drive shaft 46.

[0085] The front end of the coil sheath 49c is fixed to a predetermined position on the front end of the flexible tube 14. The base end of the coil sheath 49c is fixed to the front end of the anti-bending member 24. The length of the central axis c49c of the elastic coil sheath 49c increases with the amount of bending when the flexible tube 14 bends.

[0086] The drive shaft 46 is a stranded wire formed by twisting multiple wires together as described above. When the flexible tube 14 bends, the length of the drive shaft 46, which is a stranded wire, remains almost unchanged. Furthermore, when the flexible tube 14 is straight, the shaft center axis c46 and the sheath center axis c49c are approximately aligned with the length axis a10.

[0087] A magnet 46m is fixedly installed near the connection between the drive shaft 45 and the rotating component 47. Reference numeral 51B is a magnetic sensor. The magnetic sensor 51B has the function of detecting the movement distance of the magnet 46m in a non-contact manner.

[0088] The magnetic sensor 51B has three detection ranges. The first detection range is from point O to point A, the second detection range is from point A to point B, and the third detection range is from point B to point C. Furthermore, the detection range is not limited to three; it can be more or less than three. As described above, the detection sensitivity of the magnetic sensor 51B can be adjusted by changing the size of the magnet 46m.

[0089] In this embodiment, when the flexible tube 14 is in a straight state, the magnet 46m is located at the base end of the coil sheath 49c and is within the first detection range. When the flexible tube 14 changes from a straight state to a bent state, the length of the sheath's central axis c49c becomes longer than the length of the shaft's central axis c46. As a result, the magnet 46m, fixed to the drive shaft 46, is pulled into the coil sheath 49c along the length axis a10 as shown by the dashed line. The amount by which the magnet 46m is pulled in, i.e., the distance moved, is detected by the magnetic sensor 51B and output to the controller 7.

[0090] The magnetic sensor 51B outputs a first detection signal when the magnet 46m is within a first detection range along the length axis a10, a second detection signal when it is within a second detection range, and a third detection signal when it is within a third detection range. Then, when it exceeds point C, the output of the detection signal stops.

[0091] In this embodiment, when the flexible tube 14 is in a straight state, the magnet 46m is located at the base end of the coil sheath 49c between point O and point A.

[0092] When the forward switch F is operated, the magnetic sensor 51B becomes operational via the controller 7. When the magnetic sensor 51B is operational, it outputs a first detection signal to the controller 7 when the magnet 46m is within a first detection range. Conversely, it outputs a second detection signal to the controller 7 when the magnet 46m is within a second detection range.

[0093] Upon receiving the detection signal, the controller 7 determines that the movement distance detection has started and the motor drive has started. The controller 7 supplies the drive current corresponding to the detection signal, i.e., the first drive current or the second drive current, to the motor 41 to drive the motor 41.

[0094] When the coil sheath 49c bends, as shown by arrow Y5, the magnet 46m is pulled into the coil sheath 49c. The distance the magnet 46m moves in the direction of the length axis a10 is measured by the magnetic sensor 51B.

[0095] The magnetic sensor 51B outputs a first detection signal to the controller 7 until the magnet 46m passes point A, then outputs a second detection signal to the controller 7 until the magnet 46m passes point B, and finally outputs a third detection signal to the controller 7 until the magnet 46m passes point C.

[0096] When different detection signals are input to the controller 7 in the motor driving state, it is determined that the driving force of the motor 41 has changed, and the controller 7 controls the motor 41 by supplying a different driving current than the driving current supplied to the motor 41 in the driving state.

[0097] Furthermore, when the magnet 46m exceeds point C, the magnetic sensor 51B stops outputting the detection signal from the magnetic sensor 51B to the controller 7. As a result, the controller 7 switches from controlling the drive motor 41 to controlling the motor 41 to stop it.

[0098] According to this structure, the controller 7 receives the detection signal output from the magnetic sensor 51B to determine the relative position of the coil sheath 49c and the magnet 46m. Regardless of the bending state of the flexible tube 14, it outputs the optimal drive current to the motor 41 to control the motor 41. As a result, regardless of the bending shape of the flexible tube 14, the solenoid 15 rotates with the optimal drive current in match to the bending state of the coil sheath 49c. Furthermore, the solenoid 15 stops rotating when the magnet 46m exceeds point C, when the bending shape of the coil sheath 49c is deformed to an angle exceeding a specified range, or when the flexible tube 14 is complexly bent.

[0099] Other structures are the same as those in the above embodiments, and the same components are labeled with the same reference numerals and the descriptions are omitted.

[0100] This invention is not limited to the embodiments described above, and various modifications or applications can be made without departing from the spirit of the invention.

Claims

1. An insertion device, characterized in that, have: A flexible tube that extends along its length axis and is flexible; A driving source is disposed at the base end of the flexible tube; A driven component is disposed at the front end of the flexible tube; A transmission component, which is inserted into the flexible tube, extends outward from the base end of the flexible tube along the length axis of the flexible tube, rotates about the axis by the driving force of the drive source, and transmits the rotation to the driven component; as well as A detection device that detects the position of a predetermined part of the transmission component along the length axis of the flexible tube; The transmission component includes stranded wire, which twists wires together to have predetermined elasticity, flexibility, and torque transmission properties.

2. The insertion device according to claim 1, characterized in that, The insertion device includes a determination unit that determines the bending state of the flexible tube based on the detection result of the detection device.

3. The insertion device according to claim 2, characterized in that, When the detection device detects that the position of the predetermined part of the transmission component relative to the stationary component along the length axis is a predetermined position, the detection device outputs a detection signal to the determination unit, wherein the stationary component is disposed on the base end side of the flexible tube.

4. The insertion device according to claim 3, characterized in that, The predetermined location of the transmission component is the base end of the transmission component along the length axis.

5. The insertion device according to claim 4, characterized in that, The detection device detects when the base end of the transmission component approaches a predetermined distance toward the stationary component disposed at the base end of the flexible tube.

6. The insertion device according to claim 1, characterized in that, An endoscope is constructed by configuring an operating part at the base end of the flexible tube.

7. An insertion device, characterized in that, have: A flexible tube that extends along its length axis and is flexible; A driving source is disposed at the base end of the flexible tube; A driven component is disposed at the front end of the flexible tube; A transmission component, which is inserted into the flexible tube, extends outward from the base end of the flexible tube along the length axis of the flexible tube, rotates about the axis by the driving force of the drive source, and transmits the rotation to the driven component; A sheath, configured to cover the outer periphery of the transmission component; as well as A detection device that detects the relative positions of a predetermined part of the sheath and a predetermined part of the transmission component along the length axis of the flexible tube. The transmission component twists the wires together to achieve predetermined elasticity, flexibility, and torque transmission.

8. The insertion device according to claim 7, characterized in that, The insertion device includes a determination unit that determines the bending state of the flexible tube based on the detection result of the detection device.

9. The insertion device according to claim 7, characterized in that, The sheath is a wound coil disposed on the outer peripheral side of the transmission component.

10. The insertion device according to claim 9, characterized in that, The detection device detects the relative position of the sheath and the transmission component at predetermined locations along the length axis.

11. The insertion device according to claim 10, characterized in that, The detection device detects the relative movement distance along the length axis when a predetermined part of the transmission component is pulled into the sheath.

12. The insertion device according to claim 7, characterized in that, The front ends of the transmission component and the sheath are respectively fixed to the flexible tube.

13. The insertion device according to claim 7, characterized in that, The position of the base end side of the sheath along the length axis is fixed relative to the flexible tube. The position of the base end of the transmission component along the length axis can be displaced relative to the flexible tube.

14. The insertion device according to claim 13, characterized in that, The insertion device has a detection device that detects the position of the base end side of the transmission member along the length axis.

15. The insertion device according to claim 7, characterized in that, An endoscope is constructed by configuring an operating part at the base end of the flexible tube.

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