CONTINUUM ROBOT SYSTEM, METHOD FOR CONTROLLING SAME, AND NON-TRANSITORY STORAGE MEDIUM STORING PROGRAM

A continuum robot system includes: a continuum robot including a bendable body configured to bend via a plurality of linear members and a tensile force detector that detects tensile forces that have occurred in the linear members; a support base including a moving stage to which the continuum robot is attached, and a second drive source that slides the moving stage; and a control apparatus that controls, in a case where the tensile forces of the plurality of linear members are tensile forces in a same direction and at least one of the tensile forces exceeds a predetermined value when the second drive source is driven in a direction in which the bendable body is inserted into a target, the second drive source such that the second drive source is stopped or driven in an opposite direction.

TECHNICAL FIELD

The present invention relates to a continuum robot system, a method for controlling the same, and a non-transitory storage medium storing a program.

BACKGROUND ART

A medical device including a continuum robot is used. PTL 1 discloses a configuration in which a medical tool including a manipulator detects a tensile force that has occurred in a drive wire, and causes a tip flexing part to be in a flexed state along a channel member by controlling an amount by which the drive wire is driven by a drive motor such that the tensile force is in a target control range set in advance. Thus, in a case where the manipulator is inserted through the channel member and sent to a site for use, it is possible to easily perform the insertion operation.

CITATION LIST

Patent Literature

Since an organ that is in a human body and is treated as a target is complex, a distal end of a bendable body of a continuum robot may come into contact with an inner wall of the organ almost from the front when the bendable body of the continuum robot is inserted in the target. When the bendable body comes into contact with the inner wall of the organ, the bendable body may not be released from the contact only by controlling the flexing of the bendable body based on the tensile force as in PTL 1. When such a situation occurs, it is difficult to further insert the bendable body in the target.

SUMMARY OF INVENTION

The present invention has been made in view of the above-described circumstances, and aims at easily releasing a bendable body of a continuum robot from contact when the bendable body of the continuum robot is inserted in a target.

A continuum robot system according to the present invention includes: a continuum robot including a bendable body configured to bend via a plurality of linear members, a first drive source that moves the linear members, and a tensile force detector that detects tensile forces that have occurred in the linear members; a support base including a moving stage to which the continuum robot is attached, and a second drive source that slides the moving stage; and control means that controls, in a case where the tensile forces of the plurality of linear members detected by the tensile force detector are all tensile forces in a same direction and at least one of the tensile forces exceeds a predetermined value when the second drive source is driven in a direction in which the bendable body is inserted into a target, the second drive source such that the second drive source is stopped or driven in an opposite direction.

DESCRIPTION OF EMBODIMENTS

Hereinafter, Examples of the present invention will be described with reference to the drawings. Dimensions, materials, shapes, arrangements, and the like of constituent components described in Examples should be changed as appropriate according to configurations of apparatuses, various conditions, and the like to which the present invention is applied.

Medical System and Medical Device

A medical system1A and a medical device1including a continuum robot will be described with reference toFIGS.1and2.FIG.1is an overall view of the medical system1A.FIG.2is a perspective view illustrating the medical device1and a support base2.

The medical system1A is an example of a continuum robot system and includes the medical device1, the support base2supporting the medical device1, and a control apparatus3that controls the medical device1. In the present Example, the medical system1A includes a monitor4as a display device.

The medical device1includes a catheter unit (bendable unit)100having a catheter11as a bendable body, and a base unit (drive unit, unit for attachment)200. The catheter unit100is detachably attached to the base unit200.

In the present Example, a user of the medical system1A and the medical device1inserts the catheter11into a target, and performs work such as observing the inside of the target, collecting various specimens from the inside of the target, and treating the inside of the target. As one embodiment, the user can insert the catheter11into a patient as the target. Specifically, the user can perform work such as observing, collecting, and resecting a lung tissue by inserting the catheter11into a bronchus through an oral cavity or a nasal cavity.

The catheter11can be used as a guide (sheath) that guides a medical tool for performing the above-described work. Examples of the medical tool (tool) are an endoscope, forceps, an abrasion device, and the like. In addition, the catheter11itself may have a function as the above-described medical tool.

In the present Example, the control apparatus3is an example of control means according to the present invention, and includes a computing device3aand an input device3b. The input device3breceives, from the user, a command and input for operating the catheter11and the support base2. The computing device3aincludes a storage storing a program for controlling the catheter11and the support base2and various kinds of data, a random-access memory, and a central processing unit for executing the program. In addition, the control apparatus3may include an output unit that outputs a signal for displaying an image on the monitor4.

As illustrated inFIG.2, in the present Example, the medical device1is electrically connected to the control apparatus3via the support base2and a cable5coupling the base unit200of the medical device1to the support base2. The medical device1may be directly connected to the control apparatus3via a cable. The medical device1may be wirelessly connected to the control apparatus3. Further, inFIGS.1and2, the control apparatus3is illustrated as an independent constituent component, but may be included in the base unit200or the support base2.

The medical device1is detachably attached to the support base2via the base unit200. More specifically, in the medical device1, an attachment part (connection part)200aof the base unit200is detachably attached to a moving stage (receiving part)2aof the support stage2. Even in a state in which the attachment part200aof the medical device1is detached from the moving stage2a, the connection of the medical device1and the control apparatus3is maintained so that the medical device1can be controlled by the control apparatus3. In the present Example, even in a state in which the attachment part200aof the medical device1is detached from the moving stage2a, the medical device1and the support base2are connected to each other via the cable5.

The user can manually move the medical device1and insert the catheter11into the target in a state in which the medical device1is detached from the support base2(a state in which the medical device1is detached from the moving stage2a).

In addition, in a state in which the catheter11is inserted in the target and the medical device1is attached to the support base2, the user can use the medical device1. Specifically, the medical device1is moved as the moving stage2ais moved in a state in which the medical device1is attached to the moving stage2a. Then, an operation of moving the moving stage2ain a direction in which the catheter11is inserted into the target, and an operation of moving the moving stage2ain a direction in which the catheter11is pulled out of the target are performed. The movement of the moving stage2ais performed by the control apparatus3controlling a moving motor31(seeFIG.3) disposed in the support base2.

The medical device1includes a wire drive section (linear member drive section, line drive section, main body drive section)300for driving the catheter11. In the present Example, the medical device1is a robot catheter device that drives the catheter11by the wire drive section300controlled by the control apparatus3.

The control apparatus3can control the wire drive section300to perform an operation of flexing the catheter11. In the present Example, the wire drive section300is included in the base unit200. More specifically, the base unit200includes a base housing200fhousing the wire drive section300. That is, the base unit200includes the wire drive section300.

In this case, an end at which a tip of the catheter11that is to be inserted into the target is disposed in an extension direction of the catheter11is referred to as a distal end. An end opposite to the distal end in the extension direction of the catheter11is referred to as a proximal end.

The catheter unit100includes a proximal end cover16covering the proximal end side of the catheter11. The proximal end cover16has a tool hole16a. The medical tool can be inserted into the catheter11through the tool hole16a.

As described above, in the present Example, the catheter11has a function as a guide device for guiding the medical tool to a desired position within the target.

For example, in a state in which an endoscope is inserted in the catheter11, the catheter11is inserted to a target position within the target. In this case, at least one of a manual operation by the user, the movement of the moving stage2a, and the driving of the catheter11by the wire drive section300is used. After the catheter11reaches the target position, the endoscope is pulled out of the catheter11through the tool hole16a. Then, work such as inserting the medical tool from the tool hole16aand collecting various specimens from the inside of the target and treating the inside of the target is performed.

As described above, the catheter unit100is configured to be detachably attached to the base unit200. After the medical device1is used, the user detaches the catheter unit100from the base unit200, attaches a new catheter unit100to the base unit200, and can use the medical device1again.

As illustrated inFIG.2, the medical device1includes an operation section400. In the present Example, the operation section400is included in the catheter unit100and configured to be rotatable. The operation section400is operated by the user to fix the catheter unit100to the base unit200for attachment of the catheter unit100to the base unit200and to release the fixation of the catheter unit100to the base unit200for detachment of the catheter unit100from the base unit200.

In the medical system1A configured as described above, for example, an image captured by the endoscope can be displayed on the monitor4by connecting the endoscope inserted in the catheter11to the monitor4. In addition, information regarding the state of the medical device1and the control of the medical device1can be displayed on the monitor4by connecting the monitor4to the control apparatus3. For example, information regarding the position of the catheter11in the target and navigation of the catheter11in the target can be displayed on the monitor4. The monitor4may be connected to the control apparatus3and the endoscope by wire or wirelessly. Further, the monitor4and the control apparatus3may be connected to each other via the support base2.

Support Base

The support base2will be described with reference toFIG.3.FIG.3is an explanatory diagram of the support base2.

The support base2includes a stay32. The moving motor31including a stepping motor is fixed to a motor holder33attached to the stay32. An end of a lead screw34is connected to a shaft of the moving motor31via a coupling37. The lead screw34is rotatably supported by lead screw stays35and36including bearings not illustrated. The moving stage2ato which the medical device1is fixed via the attachment part200ais connected to the lead screw34. The lead screw34is a so-called feed screw mechanism, and enables the moving stage2ato slide in an arrow direction illustrated in the drawing by converting a rotational motion of the moving motor31into a linear motion. As described above, the moving motor31is a drive source that slides the moving stage2a. The control apparatus3drives the moving motor31and controls movement of the moving stage2a.

Catheter

The catheter11as the bendable body will be described with reference toFIGS.4aand4B.FIGS.4A and4Bare explanatory diagrams of the catheter11.FIG.4Ais a diagram explaining the entire catheter11.FIG.4Bis an enlarged diagram of the catheter11.

The catheter11includes a bending part (bending body, catheter body)12and a bending drive section (catheter drive section)13configured to bend the bending part12. The bending drive section13is configured to receive a drive force of the wire drive section300through a coupling device21described later and bend the bending part12.

The catheter11is extended in the direction in which the catheter11is inserted into the target. The extension direction (longitudinal direction) of the catheter11is the same as an extension direction (longitudinal direction) of the bending part12and extension directions (longitudinal directions) of first to ninth drive wires (W11to W33) described later.

The bending drive section13includes a plurality of drive wires (drive lines, linear members, linear actuators) connected to the bending part12. Specifically, the bending drive section13includes the first drive wire W11, the second drive wire W12, the third drive wire W13, the fourth drive wire W21, the fifth drive wire W22, the sixth drive wire W23, the seventh drive wire W31, the eighth drive wire W32, and the ninth drive wire W33. The first to ninth drive wires (W11to W33) are arranged side by side along a virtual circle having a predetermined radius.

Each of the first to ninth drive wires (W11to W33) includes a part (shaft to be held, rod) Wa to be held. Specifically, the first drive wire W11includes the first part Wa11to be held. The second drive wire W12includes the second part Wa12to be held. The third drive wire W13includes the third part Wa13to be held. The fourth drive wire W21includes the fourth part Wa21to be held. The fifth drive wire W22includes the fifth part Wa22to be held. The sixth drive wire W23includes the sixth part Wa23to be held. The seventh drive wire W31includes the seventh part Wa31to be held. The eighth drive wire W32includes the eighth part Wa32to be held. The ninth drive wire W33includes the ninth part Wa33to be held.

In the present Example, the first to ninth parts (Wa11to Wa33) to be held have the same shape.

Each of the first to ninth drive wires (W11to W33) has a flexible wire body (line body, linear body) Wb. Specifically, the first drive wire W11includes the first wire body Wb11. The second drive wire W12includes the second wire body Wb12. The third drive wire W13includes the third wire body Wb13. The fourth drive wire W21includes the fourth wire body Wb21. The fifth drive wire W22includes the fifth wire body Wb22. The sixth drive wire W23includes the sixth wire body Wb23. The seventh drive wire W31includes the seventh wire body Wb31. The eighth drive wire W32includes the eighth wire body Wb32. The ninth drive wire W33includes the ninth wire body Wb33.

In the present Example, the first to third wire bodies (Wb11to Wb13) have the same shape. The fourth to sixth bodies (Wb21to Wb23) have the same shape. The seventh to ninth bodies (Wb31to Wb33) have the same shape. In the present Example, the first to ninth wire bodies (Wb11to Wb33) have the same shape, except for the lengths.

The first to ninth parts (Wa11to Wa33) to be held are fixed to the first to ninth wire bodies (Wb11to Wb33) at proximal ends of the first to ninth wire bodies (Wb11to Wb33).

The first to ninth drive wires (W11to W33) are inserted into the bending part12through a wire guide17and fixed to the bending part12via the wire guide17.

Any one of the first to ninth drive wires (W11to W33) can be referred to as a drive wire W. In the present Example, the first to ninth drive wires (W11to W33) have the same shape, except for the lengths of the first to ninth wire bodies (Wb11to Wb33).

In the present Example, the bending part12is a tube member that is flexible and has a path Ht for insertion of the medical tool.

A plurality of wire holes are provided in a wall surface of the bending part12for the first to ninth drive wires (W11to W33) to pass through the wire holes. Specifically, the first wire hole Hw11, the second wire hole Hw12, the third wire hole Hw13, the fourth wire hole Hw21, the fifth wire hole Hw22, the sixth wire hole Hw23, the seventh wire hole Hw31, the eighth wire hole Hw32, and the ninth wire hole Hw33are provided in the wall surface of the bending part12. The first to ninth wire holes Hw (Hw11to Hw33) correspond to the first to ninth drive wires (W11to W33), respectively. The numbers after the reference sign Hw indicate the numbers of the corresponding drive wires. For example, the first drive wire W11is inserted into the first wire hole Hw11.

Any one of the first to ninth wire holes (Hw11to Hw33) can be referred to as a wire hole Hw. In the present Example, the first to ninth wire holes (Hw11to Hw33) have the same shape.

The bending part12includes an intermediate region12aand a bending region12b. The bending region12bis disposed at a distal end of the bending part12. In the bending region12b, a first guide ring J1, a second guide ring J2, and a third guide ring J3are disposed. The bending region12bis a region in which the magnitude and direction of flexing of the bending part12can be controlled by the bending drive section13moving the first guide ring J1, the second guide ring J2, and the third guide ring J3. InFIG.4B, an illustration of a portion of the bending part12that covers the first to third guide rings (J1to J3) is omitted.

The medical tool is guided to the tip of the catheter11by the path Ht and the first to third guide rings (J1to J3).

Each of the first to ninth drive wires (W11to W33) extends through the intermediate region12aand is fixed to any one of the first to third guide rings (J1to J3).

Specifically, the first drive wire W11, the second drive wire W12, and the third drive wire W13are fixed to the first guide ring J1. The fourth drive wire W21, the fifth drive wire W22, and the sixth drive wire W23penetrate through the first guide ring J1and are fixed to the second guide ring J2. The seventh drive wire W31, the eighth drive wire W32, and the ninth drive wire W33penetrate through the first guide ring J1and the second guide ring J2and are fixed to the third guide ring J3.

The medical device1can bend the bending part12toward a direction intersecting the extension direction of the catheter11by causing the wire drive section300to drive the bending drive section13. Specifically, the medical device1can bend the bending region12bof the bending part12in the direction intersecting the extension direction of the bending part12via the first to the third guide rings (J1to J3) by moving each of the first to ninth drive wires (W11to W33) in the extension direction of the bending part12.

The user can insert the catheter11to a target part within the target by using any one of the movement of the medical device1by hand or the moving stage2aand bending of the bending part12.

Base Unit

The base unit200and the wire drive section300will be described with reference toFIG.5AandFIG.5B.

FIGS.5A and5Bare explanatory diagrams of the base unit200and the wire drive section300.FIG.5Ais a side view illustrating an inner structure of the base unit200.FIG.5Bis a perspective view illustrating coupling of the wire drive section300, the coupling device21, and the bending drive section13.

The wire drive section300includes a plurality of drive sources (motors). In the present Example, the wire drive section300includes a first drive source M11, a second drive source M12, a third drive source M13, a fourth drive source M21, a fifth drive source M22, a sixth drive source M23, a seventh drive source M31, an eighth drive source M32, and a ninth drive source M33.

Any one of the first to ninth drive sources (M11to M33) can be referred to as a drive source M. In the present Example, the first to ninth drive sources (M11to M33) have the same configuration.

The base unit200includes the coupling device21. The coupling device21is connected to the wire drive section300. The coupling device21includes a plurality of coupling parts. In the present Example, the coupling device21includes a first coupling part21c11, a second coupling part21c12, a third coupling part21c13, a fourth coupling part21c21, a fifth coupling part21c22, a sixth coupling part21c23, a seventh coupling part21c31, an eighth coupling part21c32, and a ninth coupling part21c33.

Any one of the first to ninth coupling parts (21c11to21c33) can be referred to as a coupling part21c. In the present Example, the first to ninth coupling parts (21c11to21c33) have the same configuration.

Each of the plurality of coupling parts is connected to a respective one of the plurality of drive sources and driven by a respective one of the plurality of drive sources. Specifically, the first coupling part21c11is connected to the first drive source M11and driven by the first drive source M11. The second coupling part21c12is connected to the second drive source M12and driven by the second drive source M12. The third coupling part21c13is connected to the third drive source M13and driven by the third drive source M13. The fourth coupling part21c21is connected to the fourth drive source M21and driven by the fourth drive source M21. The fifth coupling part21c22is connected to the fifth drive source M22and driven by the fifth drive source M22. The sixth coupling part21c23is connected to the sixth drive source M23and driven by the sixth drive source M23. The seventh coupling part21c31is connected to the seventh drive source M31and driven by the seventh drive source M31. The eighth coupling part21c32is connected to the eighth drive source M32and driven by the eighth drive source M32. The ninth coupling part21c33is connected to the ninth drive source M33and driven by the ninth drive source M33.

As illustrated inFIG.5B, the bending drive section13including the first to ninth drive wires (W11to W33) of the catheter11is coupled to the coupling device21. The bending drive section13receives a drive force of the wire drive section300through the coupling device21and bends the bending part12.

The drive wire W is coupled to the coupling part21cvia the part Wa to be held. Each of the plurality of drive wires is coupled to a respective one of the plurality of coupling parts.

Specifically, the first part Wa11that is to be held and is included in the first drive wire W11is coupled to the first coupling part21c11. The second part Wal2that is to be held and is included in the second drive wire W12is coupled to the second coupling part21c12. The third part Wa13that is to be held and is included in the third drive wire W13is coupled to the third coupling part21c13. The fourth part Wa21that is to be held and is included in the fourth drive wire W21is coupled to the fourth coupling part21c21. The fifth part Wa22that is to be held and is included in the fifth drive wire W22is coupled to the fifth coupling part21c22. The sixth part Wa23that is to be held and is included in the sixth drive wire W23is coupled to the sixth coupling part21c23. The seventh part Wa31that is to be held and is included in the seventh drive wire W31is coupled to the seventh coupling part21c31. The eighth part Wa32that is to be held and is included in the eighth drive wire W32is coupled to the eighth coupling part21c32. The ninth part Wa33that is to be held and is included in the ninth drive wire W33is coupled to the ninth coupling part21c33.

The base unit200includes a base frame25. The base frame25has a plurality of insertion holes through which the first to ninth drive wires (W11to W33) extend. The base frame25has the first insertion hole25a11, the second insertion hole25a12, the third insertion hole25a13, the fourth insertion hole25a21, the fifth insertion hole25a22, the sixth insertion hole25a23, the seventh insertion hole25a31, the eighth insertion hole25a32, and the ninth insertion hole25a33. The first to ninth insertion holes (25a11to25a33) correspond to the first to ninth drive wires (W11to W33), respectively. The numbers after the reference sign25aindicate the numbers of the corresponding drive wires. For example, the first drive wire W11is inserted into the first insertion hole25al1.

Any one of the first to ninth insertion holes (25a11to25a33) can be referred to as an insertion hole25a. In the present Example, the first to ninth insertion holes (25a11to25a33) have the same shape.

The first to ninth drive wires (W11to W33) engage with the corresponding first to ninth insertion holes (25a11to25a33) and the corresponding first to ninth coupling parts (21c11to21c33), respectively.

The base frame25includes a key receiving part (key hole, base side key, main body side key)22that receives a key shaft included in the catheter unit100. The catheter unit100is attached to the base unit200in a correct phase since the key shaft15engages with the key receiving part22.

In addition, the base frame25includes a connection shaft26. As illustrated inFIG.9, a connection groove400athat engages with the connection shaft26is disposed on the inner side of the operation section400. When the catheter unit100is attached to the base unit200, the connection shaft26engages with the connection groove400avia an entrance port400aland moves along the connection groove400aaccording to the rotational position (see a locking direction R1and an unlocking direction R2) of the operation section400.

Coupling of Driving Sources to Drive Wires

The coupling of the wire drive section300, the coupling device21, and the bending drive section13will be described with reference toFIGS.6A and6B.FIGS.6A and6Bare explanatory diagrams of the wire drive section300, the coupling device21, and the bending drive section13.FIG.6Ais a perspective view of the drive source M, the coupling part21c, and the drive wire W.FIG.6Bis an enlarged view of the coupling part21cand the drive wire W.

In the present Example, configurations in which the first to ninth drive wires (W11to W33) are coupled to the first to ninth coupling parts (21c11to21c33), respectively, are the same. In addition, configurations in which the first to ninth coupling parts (21c11to21c33) are connected to the first to ninth drive sources (M11to M33), respectively, are the same. Therefore, in the following description, a single drive wire W, a single coupling part21c, and a single drive source M are used to explain a configuration in which the single drive wire W, the single coupling part21c, and the single drive source M are connected to each other.

As illustrated inFIG.6A, the drive source M includes an output shaft Ma that is a motor shaft, and a motor body Mb that rotates the output shaft Ma in a rotation direction Rm. A spiral groove is disposed on a surface of the output shaft Ma. The output shaft Ma has a so-called screw shape. The motor body Mb is fixed to a motor flame200b.

The coupling part21cincludes a tractor21ctconnected to the output shaft Ma, and a tractor support shaft21cssupporting the tractor21ct. The tractor support shaft21csis connected to a coupling base21cbvia a force sensor21cf. The force sensor21cffunctions as a tensile force detector and outputs, to the control apparatus3, an electric signal that is a detected value according to a tensile force that has occurred in the drive wire W. The force sensor21cfwill be described later in detail.

The coupling part21cincludes a plate spring21chas a holding part for holding the part Wa that is to be held and is included in the drive wire W. The drive wire W extends through the insertion hole25aand engages with the coupling part21c. More specifically, the part Wa to be held engages with the plate spring21ch. As described later, the plate screw21chcan be in a state (fixing state) in which the plate screw21chsandwiches and fixes the part Wa to be held and a state (releasing state) in which the plate screw21chreleases the part Wa to be held.

The coupling part21cincludes a pressing member21cp. The pressing member21cpincludes a gear part21cgengaging with an internal gear29described later, and a cam21ccas a pressing part for pressing the plate spring21ch.

As described later, the cam21cccan move with respect to the plate spring21ch. As the cam21ccmoves, the state of the plate spring21chis switched between the fixing state and the releasing state.

As illustrated inFIG.6A, the coupling part21cis supported by a first bearing B1, a second bearing B2, and a third bearing B3. The first bearing B1is supported by a first bearing frame200cof the base unit200. The second bearing B2is supported by a second bearing frame200dof the base unit200. The third bearing B3is supported by a third bearing frame200eof the base unit200.

Therefore, when the output shaft Ma rotates in the rotation direction Rm, the rotation of the coupling part21caround the output shaft Ma is restricted. The first bearing B1, the second bearing B2, and the third bearing B3are provided for the first to ninth coupling parts (21c11to21c33).

Since the rotation of the coupling part21caround the output shaft Ma is restricted, when the output shaft Ma rotates, a force along the rotational axis direction of the output shaft Ma acts on the tractor21ctdue to the spiral groove of the output shaft Ma. As a result, the coupling part21cmoves along the rotational axis direction of the output shaft Ma (Dc direction). As the coupling part21cmoves, the drive wire W moves and the bending part12bends. That is, the output shaft Ma and the tractor21ctforms a so-called feed screw that converts a rotational motion transmitted from the drive source M into a linear motion by the screw.

The control apparatus3independently controls each of the first to ninth drive sources (M11to M33). That is, any drive source among the first to ninth drive sources (M11to M33) can independently operate or stop regardless of whether or not the other drive sources are in a stopped state. In other words, the control apparatus3can independently control each of the first to ninth drive wires (W11to W33). As a result, each of the first to third guide rings (J1to J3) can be independently controlled and the bending region12bof the bending part12can be flexed in any direction.

Specifically, the third guide ring J3is disposed at the proximal end of the bending part12. The seventh to ninth drive wires (W31to W33) are connected to the third guide ring J3, and the seventh to ninth drive sources (M31to M33are connected to the three drive wires. That is, by controlling the seventh to ninth drive sources (M31to M33), the orientation of the third guide ring J3can be changed to any direction, and the bending region12bbends into an arc along the third guide ring J3. Similarly, by controlling the fourth to sixth drive sources (M21to M23), the orientation of the second guide ring J2can be changed to any direction via the fourth to sixth drive wires (W21to W23). Similarly, by controlling the first to third drive sources (M11to M13), the orientation of the first guide ring J1can be changed to any direction via the first to third drive wires (W11to W13).

As described above, since each of the three guide rings (J1to J3) can be independently oriented in any direction, the bending region12bcan be in a complex shape. Therefore, the catheter11can be inserted into and moved in a long and thin organ having a complex shape, such as the bronchus and a digestive organ inside the patient's body.

Force Sensor

The force sensor21cfwill be described with reference toFIG.7.FIG.7is an explanatory diagram of the force sensor21cf.

As illustrated inFIGS.6A and6B, the force sensor21cfthat detects a tensile force that has occurred in the drive wire W is disposed in the coupling part21cof the base unit200. Since this tensile force occurs when the catheter11comes into contact with the inner wall of the organ, it is possible to determine whether or not the catheter11is smoothly moving in the organ.

As illustrated inFIG.7, the force sensor21cfincludes a strain-generating body21cland a strain gauge21csgattached to the strain-generating body21cl, and the strain gauge21csgdetects a slight elastic deformation of the strain-generating body21clcaused by the occurrence of a tensile force in the drive wire W.

The strain-generating body21clis a square-shaped metal component with an opening in the middle of the strain-generating body21cl. The tensile force that has occurred in the drive wire W causes upper and lower horizontal walls21cl1and21c12of the strain-generating body21clto move in arrow directions in the drawing. For example, when the horizontal wall21cl1moves rightward in the drawing, the horizontal wall21c12moves leftward. Vertical walls21c13and21c14of the strain-generating body21clslightly elastically deform due to positional shifts of the horizontal walls21cl1and21cl2. The elastic deformations are detected by the strain gauge21csgattached to the vertical walls21c13and21cl4. In the Example, two strain gauges21csg1and21csg2are attached. The strain gauge21csgdeforms according to the expansion and contraction of an attachment target object and measures an amount of strain of the target object by changing a resistance value of the strain gauge21csg.

These strain gauges21csg1and21csg2and resistors R3and R4form a wheatstone bridge circuit21cwincluding the strain gauges21csg1and21csg2, and the wheatstone bridge circuit21cwis configured to convert a small change in a resistance value of the strain gauge21csginto a voltage. A voltage is applied between input terminals21cw1and21cw2of the wheatstone bridge circuit21cw, and a differential amplifier21cdamplifies the difference in electric potential between output terminals21cw3and21cw4and outputs the output voltage to the control apparatus3. The difference in electric potential between the output terminals21cw3and21cw4corresponds to the tensile force that has occurred in the drive wire W, and thus the control apparatus3can detect, based on the output voltage of the differential amplifier21cd, the tensile force that has occurred in the drive wire W. Although the wheatstone bridge circuit21cwincludes the two strain gauges21csg1and21csg2, one or more of four resistors forming the wheatstone bridge circuit21cwmay be a strain gauge.

Fixation and Release of Fixation of Bending Drive Section

A configuration for fixing the bending drive section13to the coupling device21and a configuration for releasing the fixation of the bending drive section13by the coupling device21will be described with reference toFIGS.8A,8B,9,10,11,12,13, and14.

FIGS.8A and8Bare diagrams explaining the coupling of the catheter unit100and the base unit200.FIG.8Ais a cross-sectional view of the catheter unit100and the base unit200.FIG.8Ais a cross-sectional view of the catheter unit100and the base unit200taken along a rotational axis400r.FIG.8Bis a cross-sectional view of the base unit200.FIG.8Bis a cross-sectional view of a portion of the coupling part21cof the base unit200taken along a direction orthogonal to the rotational axis400r.

FIG.9is an exploded view explaining the coupling of the catheter unit100and the base unit200.

FIGS.10,11,12,13, and14are diagrams explaining the fixation of the drive wire W by the coupling part21c.

As illustrated inFIGS.8A and9, the base unit200includes a joint (intermediate member, second transmission member)28and the internal gear29as a moving gear (interlocking gear, transmission member, first transmission member) that interlocks with the operation section400via the joint28.

The joint28includes a plurality of transmission parts28c. The internal gear29includes a plurality of transmission receiving parts29c. The plurality of transmission parts28cengage with the plurality of transmission receiving parts29c. When the joint28rotates, the rotation of the joint28is transmitted to the internal gear29.

When the catheter unit100is attached to the base unit200, an engagement part400jincluded in the operation section400engages with a joint engagement part28jof the joint28. When the operation section400rotates, the rotation of the operation section400is transmitted to the joint28. The operation section400, the joint28, and the internal gear29rotate in the same direction.

The internal gear29includes a plurality of tooth parts for switching between a state in which the first to ninth coupling parts (21c11to21c33) fix the first to ninth drive wires (W11to W33), respectively, and a state in which the first to ninth coupling parts (21c11to21c33) release the first to ninth drive wires (W11to W33), respectively. Each of the plurality of tooth parts (acting parts, switching gear parts) of the internal gear29engages with a respective one of the gear parts21cgof the pressing members21cpincluded in the first to ninth coupling parts (21cl1to21c33).

Specifically, in the present Example, the internal gear29includes a first tooth part29g11, a second tooth part29g12, a third tooth part29g13, a fourth tooth part29g21, a fifth tooth part29g22, a sixth tooth part29g23, a seventh tooth part29g31, an eighth tooth part29g32, and a ninth tooth part29g33. Each of the first to ninth tooth parts (29g11to29g33) is formed with a gap between the tooth parts.

The first tooth part29g11engages with the gear part21cgof the first coupling part21c11. The second tooth part29g12engages with the gear part21cgof the second coupling part21c12. The third tooth part29g13engages with the gear part21cgof the third coupling part21c13. The fourth tooth part29g21engages with the gear part21cgof the fourth coupling part21c21. The fifth tooth part29g22engages with the gear part21cgof the fifth coupling part21c22. The sixth tooth part29g23engages with the gear part21cgof the sixth coupling part21c23. The seventh tooth part29g31engages with the gear part21cgof the seventh coupling part21c31. The eighth tooth part29g32engages with the gear part21cgof the eighth coupling part21c32. The ninth tooth part29g33engages with the gear part21cgof the ninth coupling part21c33.

Any one of the first to ninth tooth parts (29g11to29g33) can be referred to as a tooth part29g. In the present Example, the first to ninth tooth parts (29g11to29g33) have the same configuration.

In the present Example, configurations in which the first to ninth coupling parts (21c11to21c33) are coupled to the first to ninth drive wires (W11to W33), respectively, are the same. In addition, configurations in which the first to ninth tooth parts (29g11to29g33) are connected to the first to ninth coupling parts (21c11to21c33), respectively, are the same. Therefore, in the following description, a single drive wire W, a single coupling part21c, and a single tooth part29gare used to explain a configuration in which the single drive wire W, the single coupling part21c, and the single tooth part29gare connected to each other.

In each of the first to ninth coupling parts (21c11to21c33), as the gear part21cgis moved by the internal gear29, the pressing member21cprotates and the cam21ccmoves to a pressing position and a retracted position where the cam21ccis retracted from the pressing position.

The internal gear29rotates as the operation section400is rotated. Each of the first to ninth coupling parts (21c11to21c33) operates as the internal gear29rotates. As described above, the first to ninth coupling parts (21c11to21c33) can be operated by the operation of rotating the single operation section400.

In a state in which the catheter unit100is attached to the base unit200, the operation section400can move to a fixation position and a detachment position. In addition, as described later, in a state in which the catheter unit100is attached to the base unit200, the operation section400can move to a release position. The release position is located between the fixation position and the detachment position in a rotation direction of the operation section400. In a state in which the operation section400is present at the detachment position, the catheter unit100is attached to the base unit200(temporarily attached state).

In the temporarily attached state, the drive wire W is not fixed (locked) to the coupling part21c. This state is referred to as an unlocking state of the coupling part21c. A state in which the drive wire W is fixed (locked) to the coupling part21cis referred to as a locking state of the coupling part21c.

An operation of fixing the drive wire W to the coupling part21cwill be described with reference toFIGS.10,11,12,13, and14.

After the temporarily attached state, that is, after the catheter unit100is attached to the base unit200, and before the operation section400is operated, the catheter unit100is enabled to be detached from the base unit200. A state in which the catheter unit100is enabled to be detached from the base unit200is referred to as a detachment-enabled state.

FIG.10is a diagram illustrating states of the internal gear29and the coupling part21cin the detachment-enabled state. The plate spring21chof the coupling part21cincludes a part21chafixed to the coupling base21cb, and a part21chbthat is to be pressed and comes into contact with the cam21ccof the pressing member21cp. The plate spring21chincludes a first portion21chd1and a second portion21chd2. When the catheter unit100is attached to the base unit200, the part Wa to be held is inserted into a gap between the first portion21chd1and the second portion21chd2.

The cam21ccincludes a holding surface21ccaand a pressing surface21ccb. The holding surface21ccais closer to the center21cpcof rotation of the pressing member21cpthan the pressing surface21ccbin a rotation radius direction of the pressing member21cp.

As illustrated inFIG.10, in the detachment-enabled state (state in which the operation section400is present at the detachment position), the plate spring21chis held at a position where the part21chbto be pressed is in contact with the holding surface21cca. In addition, a tooth Za1of the internal gear29and a tooth Zb1of the gear part21cgare stopped in a state in which a clearance La occurs between the tooth Za1and the tooth Zb1.

A direction in which the operation section400moves from the detachment position to the release position and the fixation position in the rotation direction of the operation section400is referred to as a locking direction (fixation direction). A direction in which the operation section400moves from the fixation position to the release position and the detachment position in the rotation direction of the operation section400is referred to as an unlocking direction. The operation section400rotates from the release position in the unlocking direction and moves to the detachment position. The operation section400rotates from the release position in the locking direction and moves to the fixation position.

In the temporarily attached state, the coupling part21cis in the unlocking state, and the fixation of the drive wire W by the coupling part21cis released.

When the coupling part21cis in the unlocking state, the cam21ccis located at the retracted position where the cam21ccis retracted from the pressing position described later. In this case, the fixation of the part Wa, which is to be held, by the plate spring21chis released. A force with which the first portion21chd1and the second portion21chd2tighten the part Wa to be held when the coupling part21cis in the unlocking state is less than a force with which the first portion21chd1and the second portion21chd2tighten the part Wa to be held when the coupling part21cis in the locking state.

In a case where the catheter unit is moved in a detachment direction Dd with respect to the base unit200in a state in which the coupling part21cis in the unlocking state, the part Wa to be held can be pulled out of the gap between the first portion21chd1and the second portion21chd2.

FIG.11is a diagram illustrating states of the internal gear29and the coupling part21cwhen the operation section400is rotated from the detachment position in the locking direction.FIG.11is a diagram illustrating states of the internal gear29and the coupling part21cin a state in which the operation section400is present at the release position.

When the operation section400is rotated in the locking direction in a state (FIG.10) in which the operation section400is present at the detachment position, the internal gear29rotates clockwise. Then, the operation section400is located at the release position.

Even when the operation section400is rotated, the key shaft15engages with the key receiving part22, and thus the rotation of the entire catheter unit100(excluding the operation section400) with respect to the base unit200is restricted. That is, the operation section400can rotate with respect to the catheter unit100and the base unit200in a state in which the entire catheter unit100(excluding the operation section400) and the base unit200are stopped.

As the internal gear29rotates clockwise, the clearance between the tooth Za1of the internal gear29and the tooth Zb1of the gear part21cgdecreases from the clearance La to a clearance Lb.

A tooth Zb2of the gear part21cgis disposed at a position where a clearance Lz between the tooth Zb2and an addendum circle (dotted line) of the tooth part29gof the internal gear29is present. Therefore, the internal gear29can rotate without interfering with the tooth Zb2. Meanwhile, the coupling part21cis kept in the same state (unlocking state) as the state illustrated inFIG.10.

When the operation section400is rotated from the state illustrated inFIG.11in the locking direction, the internal gear29further rotates clockwise. The states of the internal gear29and the coupling part21cat that time are illustrated inFIG.12.

FIG.12is a diagram illustrating the states of the internal gear29and the coupling part21cwhen the operation section400is rotated from the release position in the locking direction.

As illustrated inFIG.12, when the operation section400is rotated from the release position in the locking direction, the tooth Za1of the internal gear29and the tooth Zb1of the gear part21cgcome into contact with each other. Meanwhile, the coupling part21cis in the same state as the state illustrated inFIGS.10and11and is kept in the unlocking state.

FIG.13is a diagram illustrating a state in which the pressing member21cprotates as the operation section400rotates in the locking direction.

As illustrated inFIG.13, when the operation section400is further rotated from the state illustrated inFIG.12in the locking direction, the internal gear29further rotates clockwise.

The internal gear29rotates the gear part21cgclockwise as the internal gear29moves from the state illustrated inFIG.12to the state illustrated inFIG.13. When the gear part21cgrotates, the holding surface21ccais separated from the part21chbto be pressed and the pressing surface21ccbapproaches the part21chbto be pressed. Then, the first portion21chd1and the second portion21chd2start sandwiching the part Wa to be held.

Then, a tooth Za3of the internal gear29moves to a position where the tooth Za3is separated from a tooth Zb3of the gear part21cgwhile the part21chbto be pressed is pressed by a corner part21ccb1disposed at an end of the pressing surface21ccb. In this case, the part Wa to be held is sandwiched by the first portion21chd1and the second portion21chd2.

When the tooth Za3of the internal gear29is separated from the tooth Zb3of the gear part21cg, the transmission of a drive force from the internal gear29to the gear part21cgends. In this case, the cam21ccis in a state in which the corner part21ccb1receives a reaction force from the plate spring21ch.

The reaction force of the plate spring21chthat acts on the corner part21ccb1acts on a position separate from the center21cpcof the rotation of the pressing member21cpin a radial direction of the rotation of the pressing member21cp, and the pressing member21cprotates clockwise. In this case, the pressing member21cprotates in the same direction as a direction in which the pressing member21cpis rotated by the internal gear29rotating clockwise.

FIG.14is a diagram illustrating states of the internal gear29and the coupling part21cin a state in which the operation section400is present at the fixation position.

As illustrated inFIG.14, the pressing member21cpreceives the reaction force of the plate spring21chand further rotates from the state illustrated inFIG.13.

As illustrated inFIG.14, the pressing member21cpstops in a state in which the pressing surface21ccbof the cam21ccand the part21chbthat is to be pressed and is included in the plate spring21chare in surface contact with each other. That is, the pressing surface21ccband the surface of the part21chbto be pressed are arranged side by side on the same plane.

In this case, the coupling part21cis in the locking state. When the coupling part21cis in the locking state, the cam21ccof the pressing member21cpis located at the pressing position, and the pressing surface21ccbpresses the part21chbto be pressed.

When the coupling part21cis in the locking state, the part Wa to be held is sandwiched by the first portion21chd1and the second portion21chd2. That is, the plate spring21chis pressed by the cam21ccand the part Wa to be held is tightened by the plate spring21ch. As a result, the part Wa to be held is fixed by the plate spring21ch.

After the catheter unit100is attached to the base unit200in the above-described manner, when the operation section400is moved to the fixation position, the catheter unit100enters a fully attached state.

In the present Example, at a position where the first portion21chd1and the second portion21chd2are separated from each other, the plate spring21chpresses the part Wa to be held. Further, a flexed part21chcconnecting the first portion21chd1and the second portion21chd2is disposed between the first portion21chd1and the second portion21chd2. The flexed part21chcis disposed with a gap G between the flexed part21chcand the part Wa to be held. In this manner, the first portion21chd1and the second portion21chd2can stably fix the part Wa to be held.

When the coupling part21cis in the locking state, pulling the part Wa to be held from between the first portion21chd1and the second portion21chd2is restricted.

The tooth Za3of the internal gear29and a tooth Zb4of the gear part21cgare stopped at positions between which a clearance Lc occurs.

To release the fixation of the drive wire W to the coupling part21c, the operation section400at the fixation position is rotated in the release direction. In this case, the internal gear29rotates counterclockwise from the state illustrated inFIG.14. When the internal gear29rotates counterclockwise, the tooth Za3of the internal gear29comes into contact with the tooth Zb4of the gear part21cg, and the pressing member21cpis rotated counterclockwise.

As the internal gear29is rotated counterclockwise, the fixation of the drive wire W by the coupling part21cis released. The operations of the internal gear29and the operation of the pressing member21cpin this case are opposite to the operations described above. That is, the fixation of the drive wire W by the coupling part21cis released by an operation opposite to the above-described operation for fixing the drive wire W by the coupling part21c.

The above-described operation is performed by the first to ninth coupling parts (21c11to21c33). That is, in a process of moving the operation section400from the detachment position to the fixation position, the first to ninth coupling parts (21c11to21c33) change from the unlocking state to the locking state due to the movement (rotation) of the operation section400. In a process of moving the operation section400from the fixation position to the detachment position, the first to ninth coupling parts (21c11to21c33) change from the locking state to the unlocking state due to the movement (rotation) of the operation section400. As described above, it is possible to switch between the unlocking state and the locking state of the first to ninth coupling parts (21c11to21c33) by the operation of rotating the single operation section400.

That is, it is not necessary that an operation section for switching between the unlocking state and the locking state be provided for each of the plurality of coupling parts21cand operated by the user. Therefore, the user can easily attach and detach the catheter unit100to and from the base unit200.

A state in which each of the first to ninth drive wires (W11to W33) is fixed by each of the first to ninth coupling parts (21c11to21c33) is referred to as a first state. A state in which the fixation of each of the first to ninth drive wires (W11to W33) by each of the first to ninth coupling parts (21c11to21c33) is released is referred to as a second state.

The first state and the second state are switched in coordination with the movement of the operation section400. That is, the first state and the second state are switched in coordination with the movement of the operation section400between the detachment position and the fixation position.

The internal gear29is configured to operate in coordination with the operation section400. In the present Example, the joint28functions as a transmission member for interlocking the operation section400with the internal gear29. The internal gear29and the joint28function as an interlocking part that interlocks with the operation section400such that the first state and the second state are switched in coordination with the movement of the operation section400.

Specifically, the internal gear29and the joint28move, in coordination with the movement of the operation section400, the part (part21chbto be pressed) of the plate spring21chwith respect to the part Wa to be held in a state in which the catheter unit100is attached to the base unit200. The locking state and the unlocking state of the coupling part21care switched by the movement of the part21chbto be held.

Insertion of Catheter into Human Body

The medical device1is assumed to be inserted into the target, for example, the bronchus or the like. The catheter11is inserted into a long narrow space and moved in the long narrow space. To insert the catheter11into the target, there are a method in which the user holds the medical device1to insert the catheter11and a method in which the medical device1is attached to the moving stage2aof the support base2and the moving motor31within the support base2is driven to slide the moving stage2a.

The shape of the organ such as the bronchus is complex and it is necessary to smoothly move the catheter11without applying an unnecessary force to the inner wall of the organ.

As control for smoothly moving the catheter11, Follow The Leader control is provided. The Follow The Leader control is to cause the succeeding second guide ring J2and the succeeding first guide ring J1to pass through a path through which the third guide ring J3at the most distal end side of the catheter11has passed during the insertion in the target. The Follow The Leader control is implemented by transferring the control of the third guide ring J3at the head to the control of the succeeding second guide ring J2and the control of the succeeding first guide ring J1at different times. The different times are determined based on the speed at which the catheter11is inserted and spacing between the guide rings J1to J3. The catheter11can be smoothly moved by the Follow The Leader control even in a case where the path is a long and thin path having a complex shape, such as the bronchus. The third guide ring J3that is on the most distal end side of the catheter11is operated by the user using the input device3bof the control apparatus3.

Meanwhile, the bronchus or the like is not necessarily an ideal arc-shaped path, and the inner diameter of the path is not fixed. In addition, when the user operates the catheter11using the input device3b, the number of human errors cannot be reduced to zero. Therefore, in a state in which the catheter11is inserted in the target, the catheter11may come into contact with the inner wall of the organ and it may become difficult to move the catheter11. In this state, a tensile force occurs in the drive wire W and can be detected by the force sensor21cf. In a case where the tensile force detected by the force sensor21cfexceeds a predetermined value, control is performed to move the drive wire W and change a bent shape of the catheter11such that the tensile force becomes equal to or less than the predetermined value, that is, the tensile force is reduced. This control is generally referred to as back drive control, but is referred to as back drive control of the drive source M in the present Example. By the back drive control of the drive source M, the catheter11can have a shape along the path within the target, and can be smoothly moved without applying an excessive force to the inner wall of the organ.

The catheter11is inserted into the target while the Follow The Leader control and the back drive control described above are used. Both the Follow The Leader control and the back drive control are performed on the drive source M that changes the bent shape of the catheter11.

However, in a case where the moving motor31within the support base2is driven to slide the moving stage2a, and the catheter11is inserted into the target, it may be difficult to insert the catheter11due to the movement. For example, it is conceivable that a state in which the distal end that is the tip of the catheter11comes into contact with the inner wall of the organ from a substantially front side is caused by the movement of the catheter11by the moving motor31in the insertion direction. In this state, the moving motor31needs to be driven in an opposite direction (direction in which the moving stage2ais slid in a direction in which the catheter11is pulled out) to release the catheter11from the contact and reduce the tensile that has occurred in the drive wire W without controlling the drive source M to change the bent shape of the catheter11.

In the present Example, in a case where the catheter11comes into contact with the inner wall of the organ in a state in which the moving motor31within the support base2is driven, and it is estimated that it is difficult to further insert the catheter11, this situation is eliminated by controlling the moving motor31. Specifically, in a case where the moving stage2ais slid by driving the moving motor31, and the catheter11is inserted in the target, when tensile forces detected by force sensors (hereinafter denoted by21cf31to21cf33for convenience) connected to the seventh to ninth drive wires W31to W33connected to the third guide ring J3on the most distal end side are all tensile forces in the same direction and at least one of the tensile forces detected by the force sensors21cf31to21cf33exceeds the predetermined value, the moving motor31is driven in the opposite direction to slide the moving stage2ain the direction in which the catheter11is pulled out. It is determined whether or not the tensile forces in the drive wires W31to W33extending to the most distal end side of the catheter11are all tensile forces in the same direction and whether or not any one of the tensile forces exceeds the predetermined value. This is due to the fact that, in a case where the tensile forces detected by the force sensors21cf31to21cf33are all tensile forces in the same direction and at least one of the tensile forces detected by the force sensors21cf31to21cf33exceeds the predetermined value, it is estimated that the catheter11comes into contact with the inner wall of the organ and that it is difficult to further insert the catheter11. This control is referred to as back drive control of the moving motor31in the present Example.

A control process to be performed by the control apparatus3for releasing from contact will be described with reference toFIG.15.FIG.15is a flowchart illustrating the control process to be performed by the control apparatus3for releasing from contact.

In step S101, the control apparatus3determines whether or not the moving motor31is being driven in the direction in which the catheter11is inserted into the target. In a case where the moving motor31is being driven in the direction in which the catheter11is inserted (YES in step S101), the process proceeds to step S102. In a case where the moving motor31is not being driven in the direction in which the catheter11is inserted (NO in step S101), the determination in step S101is repeated.

In step S102, the control apparatus3determines whether or not all of values detected by the force sensors21cf31to21cf33connected to the seventh to ninth drive wires W31to W33connected to the third guide ring J3on the most distal end side have the same sign, that is, whether or not tensile forces detected by the force sensors21cf31to21cf33are all tensile forces in the same direction. In a case where all of the values detected by the force sensors21cf31to21cf33have the same sign (YES in step S102), the process proceeds to step S103. In a case where not all of the values detected by the force sensors21cf31to21cf33have the same sign (No in step S102), the process returns to step S101.

In step S103, the control apparatus3determines whether or not at least one of the values detected by the force sensors21cf31to21cf33exceeds the predetermined value, that is, whether or not at least one of the tensile forces determined to be in the same direction in step S102exceeds the predetermined value. In a case where at least one of the values detected by the force sensors21cf31to21cf33exceeds the predetermined value (YES in step S103), the process proceeds to step S104. In a case where the values detected by the force sensors21cf31to21cf33do not exceed the predetermined value (NO in step S103), the process returns to step S101.

In step S104, since it is estimated that the catheter11comes into contact with the inner wall of the organ and that it is difficult to further insert the catheter11, the control apparatus3performs the back drive control of the moving motor31and thereafter ends the process. As described above, the back drive control of the moving motor31is control for driving the moving motor31in the opposite direction to slide the moving stage2ain the direction in which the catheter11is pulled out, and details of the back drive control of the moving motor31will be described with reference toFIG.16.

Next, the back drive control of the moving motor31in step S104illustrated inFIG.15will be described with reference toFIG.16.FIG.16is a flowchart illustrating a process of the back drive control of the moving motor31.

In step S201, the control apparatus3drives the moving motor31in the opposite direction. Therefore, it is possible to release the catheter11from the contact by sliding the moving stage2ain which the catheter11is pulled out.

In step S202, the control apparatus3performs the back drive control of the drive source M on the drive source M within the base unit200. As described above, the back drive control of the drive source M is control to detect, by the force sensor21cf, a tensile force that has occurred in the drive wire W, and move the drive wire W to change a bent shape of the catheter11such that, in a case where the tensile force detected by the force sensor21fcexceeds the predetermined value, the tensile force becomes equal to or less than the predetermined value, that is, the tensile force is reduced. Therefore, it is possible to change the shape of the catheter11to a shape along the path within the target, and smoothly move the catheter11without applying an excessive force to the inner wall of the organ.

In step S203, the control apparatus3determines whether or not the value detected by the force sensor21cfand having exceeded the predetermined value in step S103illustrated inFIG.15has become equal to or less than the predetermined value. In a case where the value detected by the force sensor21cfhas become equal to or less than the predetermined value (YES in step S203), the process proceeds to step S204. In a case where the value detected by the force sensor21cfhas not become equal to or less than the predetermined value (NO in step S203), the determination in step S203is repeated. As described above, in a case where the value detected by the force sensor21cfand having exceeded the predetermined value in step S103illustrated inFIG.15exceeds the predetermined value, the value detected by the force sensor21cfis continuously monitored, and the moving motor31and the drive source M are continuously driven until the value detected by the force sensor21cfbecomes equal to or less than the predetermined value.

In step S204, the control apparatus3stops driving the moving motor31and the drive source M and ends the process.

As described above, in a case where the catheter11comes into contact with the inner wall of the organ and it is estimated that it is difficult to further insert the catheter11, it is possible to release the catheter11from the contact by driving the moving motor31in the opposite direction to slide the moving stage2ain the direction in which the catheter11is pulled out. Then, by performing the back drive control of the drive source M at that time, it is possible to change the shape of the catheter11to a shape along the path within the target and to smoothly move the catheter11without applying an excessive force to the inner wall of the organ.

Next, Example 2 will be described. Basic configurations and processing operations of the medical system1A and the medical device1are similar to those described in Example 1. Constituent elements common to Example 1 are denoted by the same reference signs, description thereof is omitted, and differences from Example 1 will be mainly described.

As described in Example 1, the Follow The Leader control is provided as control for smoothly moving the catheter11. The Follow The Leader control is performed such that as the catheter11is inserted into the target, the succeeding parts pass through the same path as a path through which the preceding part has passed.

That is, every time the catheter11is moved by the moving motor31, a bent shape of the preceding part is stored. Then, when the catheter11is further moved, the succeeding parts reproduce the bent shape of the preceding part stored at an insertion position. The insertion position where the catheter11is inserted in the target is an amount by which the moving stage2aon which the medical device1is placed is slid. The amount by which the moving stage2ais slid is an amount by which the moving motor31is driven. The amount by which the moving motor31is driven can be calculated by counting the number of drive pulses of the moving motor31or providing an encoder or the like and detecting a rotation amount of the moving motor31. In addition, the bent shape of the catheter11is determined based on an amount by which the drive wire W is moved. The amount by which the drive wire W is moved is an amount by which the drive source M is driven. The amount by which the drive source M is driven can be detected by an encoder disposed in the drive source M. Storing the amount by which the drive source M is driven for each insertion position of the catheter11means storing a bent shape of the catheter11in time series. As the insertion position of the catheter11is advanced by the moving motor31, the succeeding parts (second guide ring J2and first guide ring J1) reach the stored insertion position. The succeeding parts can reproduce the bent shape of the preceding part at the same insertion position by reading amounts by which the drive sources M are driven for the preceding parts (the third guide ring J3for the second guide ring J2, and the second guide ring J2for the first guide ring J1) and that have been stored together with the insertion position, and driving the drive sources M by the same amounts as the read drive amounts. By continuously performing this, the Follow The Leader control is implemented.

Meanwhile, when the moving motor31is driven in the opposite direction to slide the moving stage2ain the direction in which the catheter11is pulled out, it is necessary to smoothly move the catheter11. In this case, when the drive source M is driven by the same amount as the amount by which the drive source M has been driven at the past same insertion position, it is possible to reproduce a bent shape of the catheter11at that time. Therefore, the shape of each of the parts of the catheter11can be changed to a bent shape that enables the part to pass through the same path as a path through which a part among the parts of the catheter11has already passed, and it is possible to smoothly pull the catheter11out of the inside of the target. This is referred to as Follow The Leader control for reverse rotation.

In Example 2, as illustrated inFIG.15, the control apparatus3performs a control process for releasing from contact. In this case, the Follow The Leader control for reverse rotation is performed when the back drive control of the moving motor31in step S104is performed. That is, a bent shape of the catheter11is controlled to be the same as a bent shape at the same insertion position stored in a memory that is a storage unit.

First, the Follow The Leader control for reverse rotation will be described with reference toFIGS.17and18.

FIG.17is a flowchart illustrating a data acquisition process for the Follow The Leader control.

In step S301, the control apparatus3determines whether or not the moving motor31is being driven. In a case where the moving motor31is being driven (YES in step S301), the process proceeds to step S302. In a case where the moving motor31is not being driven (NO in step S301), the determination in step S301is repeated.

In step S302, the control apparatus3stores, to the memory, an amount by which the moving motor31is driven and that is information indicating the insertion position of the catheter11.

In step S303, the control apparatus3stores, to the memory, an amount by which the drive source M is driven and that is information indicating a bent shape of the catheter11, in association with the amount by which the moving motor31is driven and that has been stored in step S302. Then, the process returns to step S301again.

By performing the data acquisition process each time the moving motor31is driven, data in which an insertion position of the catheter11is associated with a bent shape of the catheter11is accumulated in the memory. The data is also used for the Follow The Leader control, and thus is constantly in operation while the medical device1is in use.

FIG.18is a flowchart illustrating a process of the Follow The Leader control for reverse rotation.

In step S401, the control apparatus3determines whether or not the moving motor31is being driven in the opposite direction. In a case where the moving motor31is being driven in the opposite direction (YES in step S401), the process proceeds to step S402. In a case where the moving motor31is not being driven in the opposite direction (NO in step S401), the determination in step S401is repeated.

In step S402, the control apparatus3searches for, from the memory, the same drive amount as an amount by which the moving motor31is driven in the opposite direction in step S401, that is, past data of the same insertion position.

In step S403, the control apparatus3reads an amount by which the drive source M is driven and that is associated with the amount by which the moving motor31is driven and that has been searched in step S401.

In step S404, the control apparatus3drives the drive source M by the same amount as the amount by which the drive source M is driven and that has been read in step S403. Then, the process returns to step S401again, and the same control is repeated for a time period for which the moving motor31is continuously driven in the opposite direction.

Next, the back drive control of the moving motor31in step S104illustrated inFIG.15will be described with reference toFIG.19.FIG.19is a flowchart illustrating a process of the back drive control of the moving motor31.

In step S501, the control apparatus3drives the moving motor31in the opposite direction. Therefore, it is possible to slide the moving stage2ain the direction in which the catheter11is pulled out, and release the catheter11from contact.

In step S502, the control apparatus3performs the Follow The Leader control for reverse rotation on the drive source M within the base unit200. The Follow The Leader control for reverse rotation is described above with reference toFIGS.17and18. Therefore, it is possible to deform each of the parts of the catheter11into a bent shape that enables the part to pass through the same path as a path through which a part among the parts has already passed, and it is possible to smoothly pull the catheter11out of the inside of the target.

In step S503, the control apparatus3determines whether or not the value detected by the force sensor21cfand having exceeded the predetermined value in step S103illustrated inFIG.15has become equal to or less than the predetermined value. In a case where the value detected by the force sensor21cfhas become equal to or less than the predetermined value (YES in step S503), the process proceeds to step S504. In a case where the value detected by the force sensor21cfhas not become equal to or less than the predetermined value (NO in step S503), the process proceeds to step S505.

In step S505, the control apparatus3determines whether or not the amount by which the moving motor31is driven has become equal to or greater than a predetermined value. In a case where the amount by which the moving motor31is driven has become equal to or greater than the predetermined value (YES in step S505), the process proceeds to step S504. In a case where the amount by which the moving motor31is driven has not become equal to or greater than the predetermined value (NO in step S505), the process returns to step S503. For example, the patient may move or the like, and the shape of the path within the target may change. In this case, the catheter11may have a bent shape before the change by performing the Follow The Leader control for reverse rotation, a tensile force that has occurred in the drive wire W may not be reduced, and the moving motor31may be continuously driven in the opposite direction. Therefore, after the back drive control of the moving motor31is started, in a case where the value detected by the force sensor21cfdoes not become equal to or less than the predetermined value (NO in step S503), the control apparatus3determines whether or not the amount by which the moving motor31is driven has become equal to or greater than the predetermined value as in this step. In a case where the amount by which the moving motor31is driven has become equal to or greater than the predetermined value, the control apparatus3determines that the shape of the path within the target has changed for some reason, the bent shape of the catheter11is not along the shape of the path, and the tensile force that has occurred in the drive wire W is not reduced, and the process proceeds to step S504.

In step S504, the control apparatus3stops driving the moving motor31and the drive source M and ends the process.

As described above, in a case where the catheter11comes into contact with the inner wall of the organ and it is estimated that it is difficult to further insert the catheter11, the moving motor31is driven in the opposite direction to slide the moving stage2ain a direction in which the catheter11is pulled out and thus the catheter11can be easily released from the contact. Then, by performing the Follow The Leader control for reverse rotation at that time, each of the parts of the catheter11can be deformed into a bent shape that enables the part to pass through the same path as a path through which a part among the parts of the catheter11has already passed. Therefore, the catheter11can be smoothly pulled out of the inside of the target.

FIG.20illustrates an example of a hardware configuration for implementing the control means of the present invention. As the hardware configuration for implementing the control means of the present invention, a CPU2701, a memory2702, a storage device2703, an input device2704, and an output device2705are provided and connected to each other via a bus2706.

The CPU2701executes a program stored in the storage device2703. As a result, the processes in the flowcharts described above are performed. As the CPU2701executes the program, functions of acquisition means, notification means, and control prohibition means according to the present invention are implemented. The memory2702temporarily stores the program and data read by the CPU2701from the storage device2703. In addition, the memory2702is also used as a region for the CPU2701to execute various programs. The storage device2703stores an operating system (OS), various programs, and various data. The input device2704is a functional unit that receives input from the user, and for example, a keyboard and a mouse are used. The output device2705outputs information input by the input device2704and results of executing the programs by the CPU2701.

Although the present invention is described above together with the embodiments, the above-described embodiments are merely examples of implementation of the present invention, and the technical scope of the present invention should not be construed to be limited by these embodiments. That is, the present invention can be implemented in various forms without departing from the technical idea thereof or the main features thereof.

Other Embodiments

The present invention can be implemented by supplying a program that implements one or more of the functions described in the embodiments to a system or an apparatus via a network or a storage medium, and reading and executing the program by one or more processors in a computer of the system or the apparatus. In addition, the present invention can also be implemented by a circuit (for example, an ASIC) that implements one or more of the functions.

According to the present invention, it is possible to easily release a bendable body of a continuum robot from contact when the bendable body of the continuum robot is inserted in a target.