JP2005103056A - Inner force sense detector and manipulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inner force sense detector for detecting only distal end force with high sensitivity. <P>SOLUTION: The detector is provided with: an operation part 20 provided on the tip side of an arm part 40 to be inserted to the inside of an inspection subject B; and a driving part 30 provided on the proximal end side of the arm part 40. The arm part 40 is provided with: an inner tube 50 for housing, in its inside, a driving force transmitting mechanism 60 for transmitting driving force from the side of the driving part 30 to the operation part 20; and an inner force sense detection part 100 which is provided coaxially on the distal end side of the inner tube 50 and to which the deformation of an inner tube 50 is transmitted. The inner force sense detection part 100 is provided with: a fixed part 120 fixed to the outer peripheral wall of the inner tube 50; an engaging part 130 arranged at a position separated in the axial direction from the fixed part 120, engaged with the outer peripheral wall of the inner tube 50 in a direction crossing with the axial direction and engaged movably in the axial direction; a connection part 140 for connecting the fixed part 120 and the engaging part 130 integrally; and deformation gauges 151 to 154 for detecting the amount of deformation of the connection part 140. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a force detection device that is attached to a tip of a manipulator or the like and measures a tip force applied to the tip, and a manipulator in which the force detection device is incorporated, and particularly relates to a device that can measure the tip force with high accuracy.

  In laparoscopic surgery such as cholecystectomy, a plurality of small holes are made in the abdomen of a patient (subject), and jigs called trocars are attached to these holes. Then, through these trocars, an endoscope, forceps and the like are inserted from the hole, and the surgeon performs an operation while viewing the image of the endoscope on the monitor. Since such a surgical method does not require laparotomy, the burden on the patient is small, and the number of days until postoperative recovery and discharge is greatly reduced, and therefore, the application field is expected to expand.

  However, for the surgeon, the operation has to be performed with forceps having a low degree of freedom (for example, only opening and closing of the gripper), which requires skill. Therefore, research on a master-slave type medical manipulator in which a working unit (slave unit) having a plurality of degrees of freedom is provided at the distal end of the forceps and the distal end side driving unit (master unit) is operated is advanced. Yes.

  The master-slave type medical manipulator includes a remote type medical manipulator in which the master unit and the slave unit are not integrated, and an integrated type in which the master unit and the slave unit are integrated by an arm. . In the remote type, a slave part having a plurality of arms is arranged on the patient side, and an operation is performed by an operator operating a master part at a remote place. This is a large-scale system and expensive. Furthermore, it includes problems such as being unable to respond quickly to emergencies.

  On the other hand, an integrated medical manipulator is obtained by connecting a master unit and a slave unit via an arm, and a driving force transmission mechanism is provided inside the arm. In such a medical manipulator, it is possible to perform both a simple and reliable large and quick operation, which is an advantage of the conventional forceps, and a fine work and an operation from a difficult angle which are the advantages of the manipulator. . Further, the size is almost the same as that of a general surgical instrument, and it can be used in the environment of a conventional endoscopic operation. For this reason, both cost and safety are superior to remote medical manipulators. In the medical manipulator, the operability is improved and the burden on the operator is reduced by increasing the degree of freedom of operation in both the remote type and the integrated type.

  In such a master-slave type medical manipulator, there is a great expectation that force sense and tactile sense will be detected in order to further improve operability. In other words, the surgeon desires to perform an operation in the same manner as his / her hand from the viewpoint of operability and safety, and for this purpose, detection and presentation of force / tactile sensation is necessary. The force sense / tactile sense includes, for example, a gripping force of the working unit gripper, a tactile sensation of what is gripped by the gripper, a tip force of a force applied to the tip of the working unit, and the like. Among them, the tip force is useful haptic information that achieves both improvement in operability and safety. In other words, if the tip force is known, it is possible to detect how much the thread or the like is being pulled in terms of operability, and in terms of safety, it is possible to detect the degree of contact with an organ or the like.

  However, in the remote medical manipulator, since the master part and the slave part are physically separated, information such as force sense is not fed back to the operator at all. In addition, in an integrated medical manipulator, information such as rough force sense is fed back to the operator, but it is attenuated by the weight of the motor, friction of the trocar, etc., and information such as fine force sense is not fed back. There's a problem. For this reason, in medical manipulators, attempts are being made to feed back force / tactile information to the surgeon.

  As a method for obtaining the tip force in a medical manipulator, a method is known in which a strain sensor is directly attached to the arm to which the working unit is connected, and the strain amount of the arm that is distorted by the tip force is detected (for example, Patent Documents). 1). This is generally used as a method for obtaining the tip force applied to the working part of a conventional robot arm.

On the other hand, an operation device such as a forceps or a scalpel is arranged in a mantle inserted into a body cavity, and a force sensor is installed between the mantle and the operation device (see, for example, Patent Document 2). When the tip of the operating device receives a load force, a force acts between the mantle and the operating device, and the tip force is obtained by detecting the force with a force sensor. In this method, since it is physically separated from the manipulator, the sterilization cleaning property and the electrical safety can be improved as compared with the conventional method, and there is almost no influence of the transmission mechanism.
JP-A-8-224246 JP 2002-159509 A

  However, the above-described medical manipulator has the following problems. In other words, if a strain sensor is attached directly near the tip of the arm, the strain sensor itself enters the body cavity with the surface exposed, so it must have a structure suitable for cleaning and sterilization necessary for medical equipment. There is. In addition, since the strain sensor is energized, it is necessary to consider electrical safety for the patient.

  In addition, since the driving force transmission mechanism is provided in the arm, the arm may be affected by the stress on the arm generated by the operation of the driving force transmission mechanism. That is, when a wire is used for drive transmission, the wire tension changes each time the working unit is operated, and an axial force is applied to the arm. At this time, if the force detection unit is directly installed on the arm, an axial force due to a change in the tension of the wire is detected, and it is difficult to separate it from the tip force that is the object of detection.

  On the other hand, when an operation device such as a forceps or a scalpel is placed in the mantle inserted into the body cavity and a force sensor is installed between the mantle and the operation device, the force actually detected is not a direct force. In addition, the force applied by the controller to the trocar supported by the elastic part such as the abdomen is measured, so the tip force cannot be detected with high accuracy, and there is a subtle difference in force sense necessary for surgery, etc. Cannot be detected. Further, in this method, two or more force sensors to be installed between the mantle and the manipulator are required, and the distance between them is also required to some extent. For this reason, it is difficult to take a compact configuration.

  Therefore, in the present invention, there is provided a force detection device and a manipulator that can detect only the tip force with high sensitivity, are excellent in sterilization cleaning property and electrical safety, and can eliminate the influence from the driving force transmission mechanism. The purpose is to provide.

  In order to solve the above problems and achieve the object, the force detection device and manipulator of the present invention are configured as follows.

(1) An arm portion whose distal end is inserted into the subject, a working portion provided on the distal end side of the arm portion, and a drive portion provided on the proximal end side of the arm portion, the arm The portion is provided inside the inner tube that houses a driving force transmission mechanism that transmits the driving force from the driving unit side to the working unit, and is coaxially provided on the distal end side of the inner tube, and the inner tube is deformed. The force sense detecting unit is disposed at a position that is fixed to the outer peripheral wall of the inner tube and spaced apart in the axial direction with respect to the fixed portion. An engaging portion that is locked in a direction intersecting the axial direction with respect to the outer peripheral wall of the inner tube and is movably locked in the axial direction, the fixing portion, and the engaging portion. A connecting portion that is integrally connected; and a deformation amount detector that detects a deformation amount of the connecting portion. Force detecting apparatus according to claim.

(2) The arm includes an arm portion whose distal end is inserted into the subject, a working portion provided on the distal end side of the arm portion, and a drive portion provided on the proximal end side of the arm portion, The portion is provided inside the inner tube that houses a driving force transmission mechanism that transmits the driving force from the driving unit side to the working unit, and is coaxially provided on the distal end side of the inner tube, and the inner tube is deformed. The force sense detecting unit is disposed at a position that is fixed to the outer peripheral wall of the inner tube and spaced apart in the axial direction with respect to the fixed portion. An engaging portion that is locked in a direction intersecting the axial direction with respect to the outer peripheral wall of the inner tube and is movably locked in the axial direction, the fixing portion, and the engaging portion. A connecting portion that is integrally connected, and a pressure detector that detects a pressure that the engaging portion receives from the inner tube; Characterized in that it comprises.

(3) The force detection device according to (1), wherein the connecting portion is formed of two sets of parallel plate structures, and the deformation amount detector is attached to each plate. And

(4) The force detection device according to (1), wherein the deformation detectors are at least one pair in two axial directions orthogonal to the axial direction of the inner tube and orthogonal to each other in the connecting portion. It is characterized by being installed.

(5) The force detection device according to (1) or (2), wherein a gap is formed between an inner wall portion of the engaging portion and an outer wall portion of the inner tube. And

(6) In the force detection device described in (1) or (2) above, the inner wall portion of the engaging portion and the outer wall portion of the inner tube are tapered from the central axis side to the outer peripheral side. It is in contact with the shape.

(7) The force sense detection device according to (1) or (2), wherein the force sense detection unit is formed of an insulating material.

(8) The force detection device according to (1) or (2), wherein the fixing portion and the engagement portion of the force detection portion are formed of an insulating material, and the connection portion is a metal material. It is formed by.

(9) An arm portion whose distal end is inserted into the subject, a working portion provided on the distal end side of the arm portion, and a drive portion provided on the proximal end side of the arm portion, the arm The portion is provided inside the inner tube that houses a driving force transmission mechanism that transmits the driving force from the driving unit side to the working unit, and is coaxially provided on the distal end side of the inner tube, and the inner tube is deformed. The force sense detecting unit is disposed at a position that is fixed to the outer peripheral wall of the inner tube and spaced apart in the axial direction with respect to the fixed portion. An engaging portion that is locked in a direction intersecting the axial direction with respect to the outer peripheral wall of the inner tube and is movably locked in the axial direction, the fixing portion, and the engaging portion. A connecting portion to be connected, a deformation amount detector for detecting the deformation amount of the connecting portion, and the deformation amount detector Based on the amount of deformation is characterized in that it comprises a presentation unit that presents the external force acting on the pipe above.

(10) The arm includes an arm portion whose distal end is inserted into the subject, a working portion provided on the distal end side of the arm portion, and a drive portion provided on the proximal end side of the arm portion. The portion is provided inside the inner tube that houses a driving force transmission mechanism that transmits the driving force from the driving unit side to the working unit, and is coaxially provided on the distal end side of the inner tube, and the inner tube is deformed. The force sense detecting unit is disposed at a position that is fixed to the outer peripheral wall of the inner tube and spaced apart in the axial direction with respect to the fixed portion. An engaging portion that is locked in a direction intersecting the axial direction with respect to the outer peripheral wall of the inner tube and is movably locked in the axial direction, the fixing portion, and the engaging portion. A connecting portion to be connected, a pressure detector for detecting the pressure received by the engaging portion from the inner tube, and Based on the detected pressure change in the force detector, characterized in that it comprises a presentation unit that presents the external force acting on the pipe above.

  According to the present invention, only the tip force can be detected with high sensitivity, and it is excellent in sterilization cleaning property and electrical safety, and the influence from the driving force transmission mechanism can be eliminated.

  FIG. 1 is a perspective view showing a master-slave type medical manipulator 10 incorporating a force sense detecting unit 100 according to the first embodiment of the present invention, and FIG. 2 is an enlarged view of the distal end side of the medical manipulator 10. FIG.

The medical manipulator 10 is inserted into the body cavity of the subject B to perform work,
A driving unit 30 for an operator to operate the working unit 20 and an arm unit 40 that connects the working unit 20 and the driving unit 30 are provided.

  The arm unit 40 is provided in the inner tube 50, the inner tube 50, a driving force transmission mechanism 60 for transmitting the driving force in the driving unit 30 to the working unit 20, and a distal end side of the arm unit 40. And a force detection unit 100 detachably attached to the outer periphery. 1 indicates a trocar stabbed into the abdominal wall Ba of the subject B.

  The drive unit 30 includes a holding unit 31 where the operator holds the arm unit 40, operating handles 32 and 33 which are attached to the holding unit 31 and perform operations for operating the working unit 20, and the operating handles 32, A driving unit 34 that generates a driving force based on the operation 33 and a force sensor 35 for detecting a force received by the surgeon via the arm unit 40 are provided. The holding unit 31 is provided with a presentation unit 36 such as a warning lamp. In addition to the warning lamp, the presentation unit 36 may be any other device that can be sensed by the operator, such as a meter or a speaker.

  FIG. 2 is a side view showing the working unit 20, the inner tube 50, and the force sense detecting unit 100 with a part cut away. A screw portion 51 and a locking portion 52 are provided at the tip of the inner tube 50.

  The force sense detection unit 100 is provided to detect a tip force that is an external force applied to the working unit 20 and present it to the operator, and includes an outer tube 110 made of an insulating material. The outer tube 110 includes a fixing portion 120 that is screwed onto the screw portion 51 of the inner tube 50 on the inner wall surface side thereof, and an engagement portion 130 that engages with the locking portion 52 of the inner tube 50. The fixing portion 120 and the engaging portion 130 are integrally connected, and a connecting portion 140 is provided that is formed apart from the outer wall surface of the inner tube 50 by a predetermined distance. The inner peripheral surface of the engaging portion 130 and the outer peripheral surface of the locking portion 52 are in contact with each other, and only the movement in the direction intersecting the axial direction among the movements of the locking portion 52 is described later. Is transmitted to the engaging portion 130. In FIG. 2, 131 indicates a through hole.

  The connecting portion 140 is formed in a cylindrical shape, and as shown in FIG. 3, flat plates 141 to 144 (143 is not shown) are formed by forming four horizontal U-shaped slits S. ing. Since the flat plate 141 and the flat plate 143, and the flat plate 142 and the flat plate 144 are arranged in parallel to each other and opposed to each other, two sets of parallel flat plate structures are formed. On the inner wall surface side of each flat plate 141 to 144, four strain gauges 151 to 154 arranged every 90 degrees along the circumferential direction are provided, and are arranged at opposing positions of the parallel plate structure, respectively. . That is, the tip force applied to the force sense detection unit 100 can be detected by being decomposed in two axial directions orthogonal to the axial direction.

  The strain gauges 151 to 154 are covered with a coating agent 155 and have water resistance and heat resistance. The lead wire 157 connected to the strain gauges 151 to 154 passes through a through hole 131 provided in the engaging portion 130 and is guided to the driving portion 30 while being covered with a cover (not shown).

  In the medical manipulator 10 configured as described above, the distal force is detected at the same time as performing an operation or the like as follows. That is, the trocar T is inserted into the abdominal wall Ba of the subject B, and the working unit 20 and the arm unit 40 of the medical manipulator are inserted from the trocar T. Then, the working unit 20 is positioned on the affected part, and the surgeon operates the drive unit 30 to perform an operation or the like. At this time, a tip force including a reaction force from an organ is applied to the working unit 20. This tip force slightly deforms the inner tube 50. Accompanying this deformation, the engagement portion 52 of the inner tube 50 is transmitted to the engaging portion 130 of the force sense detecting portion 100, and the connecting portion 140 is deformed. The amount of deformation is detected by the strain gauges 151 to 154, the tip force (force and direction) is calculated, and the warning lamp of the presentation unit 36 is turned on when the tip force approaches the allowable force of the organ or surgical thread. .

  When the deformation of the inner tube 50 is transmitted to the force sense detecting unit 100, the engaging part 130 is locked in the radial direction with respect to the locking part 52 and is not restricted in the axial direction. Of the deformation of the tube 50, only the deformation in the radial direction is transmitted to the engaging portion 130. Therefore, the deformation in the axial direction of the inner tube 50 due to the operation of the driving force transmission mechanism 60 is not transmitted to the engaging portion 130, and the strain gauges 151 to 154 detect only the tip force acting on the inner tube 50. Is possible. Therefore, the influence of the force applied in the axial direction of the arm portion 40 by the driving force transmission mechanism 60 can be eliminated.

  In addition, as described above, since the slit 140 is formed in the connecting portion 140, the connecting portion 140 is easily deformed when a tip force is applied, and the detection sensitivity can be improved. Furthermore, since it has a parallel plate structure, it is possible to detect the tip force by decomposing it in two axial directions.

  Furthermore, the force applied directly to the tip is fed back to the surgeon via the arm 40, and the force detected by the force sensor 100 and the force sensor 35 is compared. To the surgeon. Thereby, the deficient force sense information can be compensated and the operability of the medical manipulator can be improved.

  In addition, it can be attached or detached by a screw by the fixing part 120 of the force sense detecting part 100. That is, a relatively inexpensive force sensor 100 is provided for an expensive manipulator body (working unit 20, driving unit 30, arm unit 40, and driving force transmission unit 60) that can withstand sterilization cleaning and the like and is used repeatedly. It can be made disposable. For this reason, there is an advantage in terms of cost and the like as compared with a medical manipulator of a type in which a force sense detection unit is fixed to the arm unit.

  Further, by using an insulating material such as plastic as the force detection unit 100, the electrical insulation of the strain gauges 151 to 154 can be sufficiently secured.

  As described above, according to the medical manipulator 10 according to the first embodiment of the present invention, only the direction intersecting the axial direction among the forces acting on the distal end side of the arm unit 40 is detected by the force sense detecting unit 100. Therefore, it is possible to eliminate the influence of the driving force transmission mechanism 60 and the like, and to detect only the tip force that the surgeon wants to know, preventing the breakage of the thread and preventing the organ from being damaged. be able to. In addition, since the strain gauges 151 to 154 of the force detection unit 100 are not exposed to the outside, electrical safety can be ensured. Furthermore, since it is detachable, it can be used as a disposable.

  In addition, although the medical manipulator 10 mentioned above was demonstrated by the integral type, you may apply to a remote type. In this case, the driving unit 30 is operated by a robot arm or the like from a position where the operator is separated.

  FIG. 5 is a side view showing a part of the periphery of the force detection unit 200 according to the second embodiment of the present invention. 5 that are the same as those in FIG. 2 are assigned the same reference numerals, and detailed descriptions thereof are omitted.

  The force sense detection unit 200 includes an outer tube 210. The outer tube 210 includes a fixing portion 220 that is screwed to the screw portion 51 of the inner tube 50 on the inner wall surface side thereof, and an engaging portion 230 that engages with the locking portion 52 of the inner tube 50. The fixing portion 220 and the engaging portion 230 are connected by fitting, and a connecting portion 240 formed to be separated from the outer wall surface of the inner tube 50 by a predetermined distance is provided. The inner peripheral surface of the engaging portion 230 and the outer peripheral surface of the locking portion 52 are in contact with each other, and only the movement in the direction intersecting the axial direction of the movement of the locking portion 52 is described later. Is transmitted to the engaging portion 230.

  The connecting portion 240 is formed in a cylindrical shape, and four strain gauges 251 to 254 (252 and 254 are not shown) are provided on the inner wall surface side every 90 degrees along the circumferential direction. Yes. That is, the tip force applied to the force sense detection unit 200 can be detected by being decomposed in two axial directions orthogonal to the axial direction.

  The strain gauges 251 to 254 are covered with a coating agent 255 and have water resistance and heat resistance. The lead wire 256 connected to the strain gauges 251 to 254 passes through a through hole 231 provided in the engaging portion 230 and is guided to the drive portion 30 while being covered by a cover (not shown).

  The fixing part 220 and the engaging part 230 are made of an insulating material, and the connecting part 240 is made of a metal material having a lower rigidity than other members such as the fixing part 220 and the engaging part 230.

  Also in the medical manipulator 10 using the force sense detection unit 200 according to the second embodiment, the same effects as the medical manipulator 10 using the force sense detection unit 100 according to the first embodiment described above. Can be obtained. Further, by using only the connecting portion 240 as a non-insulator metal material, the amount of deflection when receiving a tip force is large and the detection accuracy is improved while ensuring sufficient electrical safety as a medical device. There is a merit that you can. In addition, there is an advantage that processing is easy compared to an insulating material such as plastic.

  FIG. 6 is a side view showing a part of the periphery of the force detection unit 300 according to the third embodiment of the present invention. 6, the same functional parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The force sense detection unit 300 includes an outer tube 310. The outer tube 310 includes a fixing portion 320 that is screwed to the screw portion 51 of the inner tube 50 on the inner wall surface side thereof, and an engaging portion 330 that engages with the locking portion 52 of the inner tube 50. The fixing part 320 and the engaging part 330 are integrally connected, and a connecting part 340 is formed so as to be separated from the outer wall surface of the inner tube 50 by a predetermined distance. Note that the inner peripheral surface of the engaging portion 330 and the outer peripheral surface of the locking portion 52 are in contact with each other, and only pressure in the direction intersecting the axial direction of the movement of the locking portion 52 is described later. Is transmitted to the engaging portion 330.

  Four pressure-sensitive sensors 331 to 334 (332 and 334 are not shown) disposed at 90 degrees along the circumferential direction are provided at the contact portion of the engaging portion 330 with the locking portion 52. . The pressure sensitive sensors 331 to 334 are composed of a piezoelectric element, a pressure sensitive film, or the like. These pressure sensors 331 to 334 can detect and detect the tip force applied to the force detection unit 300 in two axial directions orthogonal to the axial direction. The pressure sensitive sensors 331 to 334 are covered with a packing 335 and have water resistance. The lead wire 336 connected to the pressure sensitive sensors 331 to 334 is covered by a cover (not shown) and guided to the driving unit 30. Further, the pressure sensors 331 to 334 may be arranged like a belt between the engaging portion 330 and the locking portion 52.

  According to the medical manipulator 10 using the force sense detection unit 300 according to the third embodiment, when a tip force is applied, a force is applied between the engagement portion 330 and the locking portion 52, and pressure sensitive. The pressure is detected by the sensors 331 to 334. Since the pressure-sensitive sensors 331 to 334 are distributed pressure sensors composed of a piezoelectric element, a pressure-sensitive film, and the like, the tip force can be detected with high accuracy, and the first embodiment described above is applied. An effect similar to that of the medical manipulator 10 using the force sense detection unit 100 can be obtained.

  FIG. 7 is a side view showing a part of the periphery of the force sense detection unit 400 according to the fourth embodiment of the present invention. In FIG. 7, the same functional parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The force sense detection unit 400 includes a fixing unit 420 that is screwed into the threaded portion 51 of the inner tube 50 on its inner wall surface side, and an engaging unit 430 that engages with the locking unit 52 of the inner tube 50. In addition, the fixing portion 420 and the engaging portion 430 are connected by fitting, and the connecting portion 440 is formed to be separated from the outer wall surface of the inner tube 50 by a predetermined distance. The inner peripheral surface of the engaging portion 430 and the outer peripheral surface of the locking portion 52 are in contact with each other, and only the movement in the direction intersecting the axial direction of the movement of the locking portion 52 is described later. Is transmitted to the engaging portion 430.

  Similar to the connection part 140 described above, the connection part 440 is formed of two sets of parallel flat plate structures, and four strain gauges 451 to 454 (452 and 454 are provided on the inner wall surface side of each flat plate 441 to 444, respectively. (Not shown) is provided. That is, the tip force applied to the force sense detection unit 400 can be detected by being decomposed in two axial directions orthogonal to the axial direction.

  The strain gauges 451 to 454 are covered with a coating agent 455 and have water resistance and heat resistance. The lead wire 456 connected to the strain gauges 451 to 454 passes through a through hole 431 provided in the engaging portion 430 and is guided to the driving portion 30 while being covered with a cover (not shown).

  As for the portion 55 covered with the connecting portion 440 in the inner tube 50, two sets of horizontal U-shaped slits S are formed, so that two parallel plate structures are formed.

  Also in the medical manipulator 10 using the force detection unit 400 according to the fourth embodiment, the same effects as those of the medical manipulator 10 using the force detection unit 100 according to the first embodiment described above. As a result, the deformation of the portion 55 of the inner tube 50 is facilitated, and the deformation of the connecting portion 440 associated therewith is enlarged, so that the measurement sensitivity can be increased as a result.

  FIG. 8 is a side view showing a part of the periphery of the force sense detecting unit 500 according to the fifth embodiment of the present invention. In FIG. 8, the same functional parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The force sense detection unit 500 includes an outer tube 510 made of an insulating material. The outer tube 510 has a fixing portion 520 that is screwed into the threaded portion 51 of the inner tube 50 on its inner wall surface side, and an engaging portion 530 that engages with the locking portion 52 of the inner tube 50. The fixing portion 520 and the engaging portion 530 are integrally connected, and a connecting portion 540 is provided that is formed apart from the outer wall surface of the inner tube 50 by a predetermined distance. Note that the inner peripheral surface of the engaging portion 530 and the outer peripheral surface of the locking portion 52 are in contact with each other, and only the movement in the direction intersecting the axial direction of the movement of the locking portion 52 is described later. Is transmitted to the engaging portion 530. In FIG. 8, reference numeral 531 denotes a through hole.

  The connecting portion 540 is formed in a cylindrical shape, and four strain gauges 551 to 554 (552 and 554 are not shown) are provided on the inner wall surface side every 90 degrees along the circumferential direction. Are arranged at opposite positions of the parallel plate structure. That is, the tip force applied to the force sense detecting unit 500 can be detected by being decomposed in two axial directions orthogonal to the axial direction.

  The strain gauges 551 to 554 are covered with a coating agent 555 and have water resistance and heat resistance. Note that the lead wire 556 connected to the strain gauges 551 to 554 passes through the through hole 531 provided in the engaging portion 530, is covered with a cover (not shown), and is guided to the driving portion 30.

  In the force sense detecting unit 500 according to the fifth embodiment, the contact surface between the engaging portion 530 and the locking portion 52 is formed in a tapered shape inclined from the central axis side to the outer peripheral side. When the inner peripheral surface of the engaging portion 530 and the outer peripheral surface of the locking portion 52 are parallel, there may be a case where there is a processing error or the like, which may not be brought into contact, which affects the detection sensitivity. By forming in a taper shape, when an axial force is applied to the outer tube 510, the engaging portion 530 and the engaging portion 52 are surely brought into contact with each other, and the detection sensitivity can be reliably maintained.

  FIG. 9 is a side view showing a part of the periphery of the force detection unit 600 according to the sixth embodiment of the present invention. 9, the same functional parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The force sense detection unit 600 includes an outer tube 610 made of an insulating material. The outer tube 610 includes a fixing portion 620 that is screwed to the screw portion 51 of the inner tube 50 on the inner wall surface side thereof, and an engaging portion 630 that engages with the locking portion 52 of the inner tube 50. The fixing portion 620 and the engaging portion 630 are integrally connected, and a connecting portion 640 is provided that is formed apart from the outer wall surface of the inner tube 50 by a predetermined distance. Note that the inner peripheral surface of the engaging portion 630 and the outer peripheral surface of the locking portion 52 are in contact with each other, and only the movement in the direction intersecting the axial direction of the movement of the locking portion 52 is described later. Is transmitted to the engaging portion 630. In FIG. 9, reference numeral 631 denotes a through hole.

  The connecting portion 640 is formed in a cylindrical shape, and four strain gauges 651 to 654 (652 and 654 are not shown) are provided on the inner wall surface side every 90 degrees along the circumferential direction. Are arranged at opposite positions of the parallel plate structure. That is, the tip force applied to the force sense detection unit 600 can be detected by being decomposed in two axial directions orthogonal to the axial direction.

  The strain gauges 651 to 654 are covered with a coating agent 655 and have water resistance and heat resistance. The lead wire 657 connected to the strain gauges 651 to 654 passes through a through hole 631 provided in the engaging portion 630 and is guided to the driving portion 30 while being covered with a cover (not shown).

  In the force sense detection unit 600 according to the fifth embodiment, a gap G having a certain size is formed between the engagement unit 630 and the locking unit 52. For this reason, when the tip force is small, the deformation amount of the inner tube 50 is small, so that the deformation is not transmitted to the force sense detection unit 600 and is not detected by the strain gauges 651 to 655. For this reason, it is applicable when only a large tip force is detected.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  According to the present invention, by transmitting only the deformation intersecting the axial direction of the deformation of the inner tube to the outer tube, it is possible to detect only the tip force with high sensitivity, as well as sterilization washing and electrical safety. Thus, a force detection device and a manipulator capable of eliminating the influence from the driving force transmission mechanism can be obtained.

The perspective view which shows the medical manipulator with which the force sense detection part which concerns on the 1st Embodiment of this invention was integrated. The side view which shows the same force sensation detection part and a work part partially cut off. The perspective view which shows typically the connection part integrated in the same force sense detection part. The perspective view which shows typically the connection part integrated in the same force sense detection part. The side view which partially cuts and shows the force sense detection part and working part which concern on the 2nd Embodiment of this invention. The side view which partially cuts and shows the force sense detection part and working part which concern on the 3rd Embodiment of this invention. The side view which partially cuts and shows the force sense detection part and working part which concern on the 4th Embodiment of this invention. The side view which partially cuts and shows the force sense detection part and working part which concern on the 5th Embodiment of this invention. The side view which partially cuts and shows the force sense detection part and working part which concern on the 6th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Medical manipulator, 20 ... Working part, 30 ... Drive part, 40 ... Arm part, 50 ... Inner tube, 60 ... Driving force transmission mechanism, 100, 200, 300, 400, 500, 600 ... Force sense detection part, Strain gauges 151-154, 251-254, 451-454, 551-554, 651-654, pressure sensors 331-334.

Claims (10)

An inner pipe,
A coaxial force sensor is provided on the distal end side of the inner tube, and a force detection unit that transmits the deformation of the inner tube.
The force sense detection unit is fixed to the outer peripheral wall of the inner tube,
It is arranged at a position spaced apart in the axial direction with respect to the fixed portion, and is locked with respect to the outer peripheral wall of the inner tube with respect to the direction intersecting the axial direction, and movably locked in the axial direction. Engaged portions;
A connecting portion that integrally connects the fixed portion and the engaging portion;
A force detection device comprising: a deformation amount detector for detecting a deformation amount of the connecting portion. An inner pipe,
A coaxial force sensor is provided on the distal end side of the inner tube, and a force detection unit that transmits the deformation of the inner tube.
The force sense detection unit is fixed to the outer peripheral wall of the inner tube,
It is arranged at a position spaced apart in the axial direction with respect to the fixed portion, and is locked with respect to the outer peripheral wall of the inner tube with respect to the direction intersecting the axial direction, and movably locked in the axial direction. Engaged portions;
A connecting portion that integrally connects the fixed portion and the engaging portion;
A force detection device comprising: a pressure detector that detects a pressure received by the engagement portion from the inner tube.   The force detection device according to claim 1, wherein the connecting portion is formed of two sets of parallel plate structures, and the deformation amount detector is attached to each plate.   2. The force sensor according to claim 1, wherein the deformation detector is attached at least one pair in two axial directions orthogonal to each other and orthogonal to the axial direction of the inner pipe in the connecting portion. .   The force sense detecting device according to claim 1, wherein a gap is formed between an inner wall portion of the engaging portion and an outer wall portion of the inner tube.   The force sense detecting device according to claim 1 or 2, wherein the inner wall portion of the engaging portion and the outer wall portion of the inner tube are in contact with each other in a tapered shape inclined from the central axis side to the outer peripheral side.   The force sense detection device according to claim 1, wherein the force sense detection unit is formed of an insulating material.   The force sense detecting device according to claim 1 or 2, wherein the fixing part and the engaging part of the force sense detecting part are made of an insulating material, and the connecting part is made of a metal material. An arm part whose distal end is inserted into the subject;
A working part provided on the tip side of the arm part;
A drive portion provided on the base end side of the arm portion,
The arm portion includes an inner pipe that houses a driving force transmission mechanism that transmits a driving force from the driving portion side to the working portion.
A coaxial force sensor is provided on the distal end side of the inner tube, and a force detection unit that transmits the deformation of the inner tube.
The force sense detection unit is fixed to the outer peripheral wall of the inner tube,
It is arranged at a position spaced apart in the axial direction with respect to the fixed portion, and is locked with respect to the outer peripheral wall of the inner tube with respect to the direction intersecting the axial direction, and movably locked in the axial direction. Engaged portions;
A connecting portion for connecting the fixing portion and the engaging portion;
A deformation amount detector for detecting the deformation amount of the connecting portion;
A manipulator comprising: a presentation unit for presenting an external force acting on the inner tube based on a deformation amount detected by the deformation amount detector. An arm part whose distal end is inserted into the subject;
A working part provided on the tip side of the arm part;
A drive portion provided on the base end side of the arm portion,
The arm portion includes an inner pipe that houses a driving force transmission mechanism that transmits a driving force from the driving portion side to the working portion.
A coaxial force sensor is provided on the distal end side of the inner tube, and a force detection unit that transmits the deformation of the inner tube.
The force sense detection unit is fixed to the outer peripheral wall of the inner tube,
It is arranged at a position spaced apart in the axial direction with respect to the fixed portion, and is locked with respect to the outer peripheral wall of the inner tube with respect to the direction intersecting the axial direction, and movably locked in the axial direction. Engaged portions;
A connecting portion for connecting the fixing portion and the engaging portion;
A pressure detector for detecting the pressure received by the engagement portion from the inner tube;
A manipulator comprising: a presentation unit for presenting an external force acting on the inner tube based on a pressure change detected by the pressure detector.

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