Patent Description:
A sterile surgical drape has been previously used to cover a surgical manipulator and a plurality of instrument manipulators <NUM> in computer-assisted surgical system <NUM>. The drapes have taken various forms. In each instance, the manipulator and associated supports links are covered with a sterile surgical drape prior to the start of a surgical procedure.

Surgical system <NUM> is a computer assisted surgical system that includes an endoscopic imaging system <NUM>, a surgeon's console <NUM> (master), and a patient side support system <NUM> (slave), all interconnected by wired (electrical or optical) or wireless connections <NUM>. One or more electronic data processors may be variously located in these main components to provide system functionality. Examples are disclosed in <CIT>. Arrow <NUM> shows the distal and proximal directions used in the discussion of <FIG>.

Imaging system <NUM> performs image processing functions on, e.g., captured endoscopic imaging data of the surgical site and/or preoperative or real time image data from other imaging systems external to the patient. Imaging system <NUM> outputs processed image data (e.g., images of the surgical site, as well as relevant control and patient information) to a surgeon at surgeon's console <NUM>. In some aspects, the processed image data is output to an optional external monitor visible to other operating room personnel or to one or more locations remote from the operating room (e.g., a surgeon at another location may monitor the video; live feed video may be used for training; etc.).

Surgeon's console <NUM> includes multiple degrees-of-freedom ("DOF") mechanical input devices ("masters") that allow the surgeon to manipulate the instruments, entry guide(s), and imaging system devices, which are collectively referred to as slaves. These input devices may in some aspects provide haptic feedback from the instruments and surgical device assembly components to the surgeon. Console <NUM> also includes a stereoscopic video output display positioned such that images on the display are generally focused at a distance that corresponds to the surgeon's hands working behind/below the display screen. These aspects are discussed more fully in <CIT>.

Control during insertion of the instruments may be accomplished, for example, by the surgeon moving the instruments presented in the image with one or both of the masters; the surgeon uses the masters to move the instrument in the image side to side and to pull the instrument towards the surgeon. The motion of the masters commands the imaging system and an associated surgical device assembly to steer towards a fixed center point on the output display and to advance inside the patient.

In one aspect, the camera control is designed to give the impression that the masters are fixed to the image so that the image moves in the same direction that the master handles are moved. This design causes the masters to be in the correct location to control the instruments when the surgeon exits from camera control, and consequently this design avoids the need to clutch (disengage), move, and declutch (engage) the masters back into position prior to beginning or resuming instrument control.

Base <NUM> of patient side support system <NUM> supports an arm assembly that includes a passive, uncontrolled setup arm assembly <NUM> and an actively controlled manipulator arm assembly <NUM>. Actively controlled manipulator arm assembly <NUM> is sometimes referred to as entry guide manipulator <NUM>.

In one example, the setup portion includes a first setup link <NUM> and two passive rotational setup joints <NUM> and <NUM>. Rotational setup joints <NUM> and <NUM> allow manual positioning of the coupled setup links <NUM> and <NUM> if the joint brakes for setup joints <NUM> and <NUM> are released. Alternatively, some of these setup joints may be actively controlled, and more or fewer setup joints may be used in various configurations. Setup joints <NUM> and <NUM> and setup links <NUM> and <NUM> allow a person to place entry guide manipulator <NUM> at various positions and orientations in Cartesian x, y, z space. A passive prismatic setup joint (not shown) between link <NUM> of arm assembly <NUM> and base <NUM> may be used for large vertical adjustments <NUM>.

A remote center of motion <NUM> is a location at which yaw, pitch, and roll axes intersect (i.e., the location at which the kinematic chain remains effectively stationary while joints move through their range of motion). Some of these actively controlled joints are manipulators that are associated with controlling DOFs of individual instruments, and others of these actively controlled joints are associated with controlling DOFs of a single assembly of these manipulators. The active joints and links are movable by motors or other actuators and receive movement control signals that are associated with master arm movements at surgeon's console <NUM>.

As shown in <FIG>, a manipulator assembly yaw joint <NUM> is coupled between an end of setup link <NUM> and a first end, e.g., a proximal end, of a first manipulator link <NUM>. Yaw joint <NUM> allows first manipulator link <NUM> to move with reference to link <NUM> in a motion that may be arbitrarily defined as "yaw" around a manipulator assembly yaw axis <NUM>. As shown, the rotational axis of yaw joint <NUM> is aligned with a remote center of motion <NUM>, which is generally the position at which an instrument enters the patient (e.g., at the umbilicus for abdominal surgery).

In one embodiment, setup link <NUM> is rotatable in a horizontal or x, y plane and yaw joint <NUM> is configured to allow first manipulator link <NUM> in entry guide manipulator <NUM> to rotate about yaw axis <NUM>. Setup link <NUM>, yaw joint <NUM>, and first manipulator link <NUM> provide a constantly vertical yaw axis <NUM> for entry guide manipulator <NUM>, as illustrated by the vertical line through yaw joint <NUM> to remote center of motion <NUM>.

A distal end of first manipulator link <NUM> is coupled to a proximal end of a second manipulator link <NUM> by a first actively controlled rotational joint <NUM>. A distal end of second manipulator link <NUM> is coupled to a proximal end of a third manipulator link <NUM> by a second actively controlled rotational joint <NUM>. A distal end of third manipulator link <NUM> is coupled to a distal portion of a fourth manipulator link <NUM> by a third actively controlled rotational joint <NUM>.

In one embodiment, links <NUM>, <NUM>, and <NUM> are coupled together to act as a coupled motion mechanism. Coupled motion mechanisms are well known (e.g., such mechanisms are known as parallel motion linkages when input and output link motions are kept parallel to each other). For example, if rotational joint <NUM> is actively rotated, joints <NUM> and <NUM> are also actively rotated so that link <NUM> moves with a constant relationship to link <NUM>. Therefore, it can be seen that the rotational axes of joints <NUM>, <NUM>, and <NUM> are parallel. When these axes are perpendicular to rotational axis <NUM> of joint <NUM>, links <NUM>, <NUM>, and <NUM> move with reference to link <NUM> in a motion that may be arbitrarily defined as "pitch" around a manipulator assembly pitch axis. The manipulator pitch axis extends into and out of the page in <FIG> at remote center of motion <NUM>, in this aspect. The motion around the manipulator assembly pitch axis is represented by arrow <NUM>. Since links <NUM>, <NUM>, and <NUM> move as a single assembly in this embodiment, first manipulator link <NUM> may be considered an active proximal manipulator link, and second through fourth manipulator links <NUM>, <NUM>, and <NUM> may be considered collectively an active distal manipulator link.

An entry guide manipulator assembly platform <NUM>, sometimes referred to as platform <NUM>, is coupled to a distal end of fourth manipulator link <NUM>. An entry guide manipulator assembly <NUM> is rotatably mounted on platform <NUM>. Entry guide manipulator assembly <NUM> includes an instrument manipulator positioning system.

Entry guide manipulator assembly <NUM> rotates a plurality of instrument manipulators <NUM> as a group around axis <NUM>. Specifically, entry guide manipulator assembly <NUM> rotates as a single unit with reference to platform <NUM> in a motion that may be arbitrarily defined as "roll" around an entry guide manipulator assembly roll axis <NUM>.

Each of a plurality of instrument manipulators <NUM> is coupled to entry guide manipulator assembly <NUM> by a different insertion assembly <NUM>. In one aspect, each insertion assembly <NUM> is a telescoping assembly that moves the corresponding instrument manipulator away from and towards entry guide manipulator assembly <NUM>. In <FIG>, each of the insertion assemblies is in a fully retracted position.

Each of the plurality of instrument manipulator assemblies includes a plurality of motors that drive a plurality of outputs in an output interface of that instrument manipulator. See <CIT>), for one example of an instrument manipulator and a surgical instrument that can be coupled to the instrument manipulator.

In one aspect, a membrane interface that is part of a sterile surgical drape may be placed between the instrument mount interface of an instrument manipulator and the input interface of the transmission unit of a corresponding surgical instrument. See, for example, U. Patent Application Publication No. <CIT> for an example of the membrane interface and sterile surgical drape. In another aspect, a sterile adapter that is part of a sterile surgical drape may be placed between the instrument mount interface of the instrument manipulator and the input interface of the transmission unit of the corresponding surgical instrument. See, for example, U. Patent Application Publication No. <CIT> for an example of a sterile adapter and a sterile surgical drape.

<FIG> illustrate perspective views of an example of a movable and/or detachable cannula mount <NUM> in a retracted position and a deployed position, respectively. Cannula mount <NUM> includes a linear extension <NUM>, i.e., a straight arm, which is movably coupled to a link <NUM> of the manipulator arm, such as an end of fourth manipulator link <NUM> (<FIG>). Cannula mount <NUM> further includes a clamp <NUM> on a distal end of linear extension <NUM>.

In one implementation, linear extension <NUM> is coupled to link <NUM> by a rotational joint <NUM> that allows linear extension <NUM> to move between a stowed position adjacent link <NUM> (<FIG>) and an operational position (<FIG>) that holds the cannula in the correct position so that the remote center of motion is located along the cannula. In one implementation, linear extension <NUM> may be rotated upwards or folded toward link <NUM>, as shown by arrow C (<FIG>), to create more space around the patient and/or to more easily drape the cannula mount when draping the manipulator arm.

<CIT> discloses a telescopic support for holding a surgical instrument having a curved slidable arm.

A surgical system includes a link of a manipulator arm and a telescoping cannula mount assembly. The link includes a curved end. The telescoping cannula mount assembly is positioned in the curved end of the link. The telescoping cannula mount assembly includes a curved cannula mount arm. In a first state, the curved cannula mount arm is parked within the curved end of the link. In a second state, the curved cannula mount arm extends from the curved end of the link and is locked in an extended position. The telescoping cannula mount assembly is configured to automatically move the curved cannula mount arm from the extended position to the parked position.

The telescoping cannula mount assembly also includes a mechanical arm retraction system. The mechanical arm retraction system couples the curved cannula mount arm to the curved end of the link. The mechanical arm retraction system is configured to automatically move the curved cannula mount arm from the second state to the first state. In one aspect, the curved cannula mount arm includes a bearing assembly that moves linearly along a curved rail that is affixed to the curved end of the link.

The mechanical arm retraction system includes a spring, a segment gear, a pinion gear, and a damper. The damper is coupled to the curved end of the link and is coupled to the curved cannula mount arm. The spring is coupled to the curved end of the link and is coupled to the curved cannula mount arm. The segment gear includes a first end and a second end. The first end of the segment gear is connected to the curved end of the link, and the second end of the segment gear is coupled to the spring. The pinion gear is coupled to the curved cannula mount arm. The pinion gear mates with the segment gear. The damper includes a shaft. The damper is connected to the curved cannula mount arm, and the pinion gear is mounted on the shaft of the damper.

The telescoping cannula mount assembly also includes a curved tray and a rolling loop electrical cable. The curved tray is connected to the curved end of the link. The rolling loop electrical cable includes a first end and a second end. The first end of the rolling loop electrical cable is connected to the curved cannula mount arm, and the second end of the rolling loop electrical cable is connected to the curved tray.

In one aspect, the curved cannula mount arm has a first end and a second end. The second end of the curved cannula mount arm is within the curved end of the link in the first state and in the second state. The telescoping cannula mount assembly also includes a latch and a latching/unlatching system. The latch is on the second end of curved cannula mount arm. When the curved cannula mount arm is in the extended position, the latching/unlatching system engages the latch to lock the curved cannula mount arm in the extended position.

The latching/unlatching system includes an electric actuator and a locking assembly connected to the electric actuator. In the extended position, the locking assembly engages the latch to lock the curved cannula mount arm in the extended position. If the electric actuator is activated, the locking assembly disengages from the latch so that the mechanical arm retraction system can automatically retract the curved cannula mount are into the link.

The telescoping cannula mount assembly also includes an interlock control system. The interlock control system includes an electric actuator bus, a bus dump circuit, and the electric actuator. The bus dump circuit and the electric actuator are connected between the electric actuator bus and a ground.

In one aspect, the curved cannula mount arm includes an arm retraction button and a cannula release button. In this aspect, the curved cannula mount arm has an outer surface and the arm retraction button has a surface. The arm retraction button is mounted in the curved cannula mount arm with the surface of the arm retraction button flush with the outer surface of curved cannula mount arm when the arm retraction button is not depressed. The cannula release button is configured to move linearly into the curved cannula mount arm with respect to the outer surface.

The surgical system also includes a cannula mount assembly. The cannula mount assembly includes a cannula docking assembly configured to dock a cannula, a linkage assembly, a cannula release button assembly having a first end and a second end, and a linear motion assembly. The cannula docking assembly is coupled to the first end of the cannula release button assembly by the linkage assembly. The second end of the cannula release button assembly is coupled to the linear motion assembly. The linear motion assembly is configured to constrain the cannula release button assembly to linear motion in first and second directions.

A method includes automatically configuring a manipulator arm assembly including a curved cannula mount arm for draping by withdrawing the curved cannula mount arm into a curved end of a link of the manipulator arm assembly by a mechanical arm retraction system in the curved end of the link.

Another method includes locking a curved cannula mount arm in an extended position from a curved link of a manipulator arm assembly by engaging a locking assembly coupled to the curved link with a latch on the curved cannula mount arm. This method also includes activating an electrical component coupled to the locking assembly to disengage the locking assembly from the latch. This method further includes inhibiting the activating of the electrical component if a cannula is docked to the curved cannula mount arm.

In general, in the drawings, the first digit of a three digit reference numeral is the figure number in which the element having that reference numeral first appeared. The first two digits of a four digit reference numeral are the figure number in which the element having that reference numeral first appeared.

<FIG> is an illustration of a patient side support system <NUM> in a computer-assisted surgical system that includes a telescoping cannula mount system <NUM>, sometimes referred to as cannula mount system <NUM>, in a curved distal end portion 319D of a fourth link <NUM> in a manipulator arm assembly <NUM>. Telescoping cannula mount system <NUM> is configured to automatically move a curved cannula mount arm <NUM> of telescoping cannula mount system <NUM> from a position extending from fourth link <NUM> to a parked position within fourth link <NUM>.

Arrow <NUM> shows the distal and proximal directions used in the discussion of <FIG>. The proximal and distal directions are an example of a first direction and a second direction opposite to the first direction. The computer-assisted surgical system includes a controller, an imaging system and a surgeon's console-all of which are coupled to patient side support system <NUM>.

In this aspect, some parts of manipulator arm assembly <NUM> are equivalent to corresponding parts in patient side support system <NUM> in <FIG>. In particular, links <NUM>, <NUM>, <NUM>, <NUM>, manipulator arm assembly <NUM>, and plurality of instrument manipulators <NUM> are equivalent to links <NUM>, <NUM>, <NUM>, <NUM>, manipulator arm assembly <NUM>, and plurality of instrument manipulators <NUM>, respectively, with the exceptions described in more detail below. In particular, link <NUM> has a curved distal end portion 319D that includes a telescoping cannula mount system <NUM>, described herein. Thus, the description associated with <FIG> is not repeated here for <FIG>, but is incorporated herein by reference.

Curved cannula mount arm <NUM>, sometimes referred to as arm <NUM> or as cannula mount arm <NUM>, is moveably mounted in telescoping cannula mount system <NUM>. In <FIG>, patient side support system <NUM> is configured for mounting a sterile surgical drape on plurality of instrument manipulators <NUM> and manipulator arm assembly <NUM>. In particular, curved cannula mount arm <NUM> is retracted into curved distal end portion 319D of link <NUM>, e.g., cannula mount arm <NUM> is parked within link <NUM>. This is a first state of cannula mount arm <NUM>, in which cannula mount system <NUM> has no stored potential energy that can be used to move cannula mount arm <NUM>. When cannula mount arm <NUM> is parked, cannula mount arm <NUM> is said to be in a first state.

Manipulator arm assembly <NUM> is covered with a sterile drape, by sliding the drape over all links, starting with plurality of instrument manipulators <NUM>, entry guide manipulator assembly <NUM> and entry guide manipulator assembly platform <NUM>, and sliding to the proximal end of first manipulator link <NUM>. With cannula mount arm <NUM> in the parked position, draping is easier, in particular when passing the drape over links <NUM>, <NUM> and <NUM>, because the effective width of the system at this point is narrower with cannula mount arm <NUM> in the parked position. The drape sleeve for cannula mount arm <NUM> does not have to be positioned about cannula mount arm <NUM> to enable the complete draping of links <NUM> to <NUM>. A cannula mount sterile adapter is mounted on a first end of cannula mount arm <NUM> that protrudes from a distal face of curved distal end portion 319D of link <NUM>. For an example of a cannula sterile adapter suitable for use with cannula mount arm <NUM>, see PCT International Publication No. <CIT>; disclosing "Surgical Cannula Mounts and Related Systems and Methods").

With cannula mount arm <NUM> parked, it allows the person doing the draping to move around curved distal end portion 319D of link <NUM> without worrying about snagging the drape on cannula mount arm <NUM>, and it provides more unencumbered space for that person to work. This is narrower than a system that has a folded linear cannula mount arm during the draping process. (See <FIG>). Moreover, curved cannula mount arm <NUM> permits retracting arm <NUM> further into curved distal end portion 319D of link <NUM> than would be possible if the prior art linear arm were retracted into curved distal end portion 319D of link <NUM>.

In some aspects, to dock a cannula to the first end of cannula mount arm <NUM>, cannula mount arm <NUM> must be in an extended and locked position. To extend cannula mount arm <NUM> from curved distal end portion 319D of link <NUM>, a user grasps the first end of cannula mount arm <NUM> and pulls cannula mount arm <NUM> from the distal end of link <NUM>.

As cannula mount arm <NUM> is pulled from the distal end of link <NUM>, the motion of arm <NUM> stores energy in an arm retraction system within telescoping cannula mount system <NUM>. When cannula mount arm <NUM> locks in the extended position, telescoping cannula mount system <NUM> stores sufficient potential energy to automatically retract cannula mount arm <NUM> back to the parked position.

In one aspect, telescoping cannula mount system <NUM> is used to automatically configure manipulator arm assembly <NUM> for draping by automatically retracting cannula mount arm <NUM> to the parked position within curved distal end portion 319D of link <NUM>. However, as explained more completely below, when cannula mount arm <NUM> is locked in the extended position and a cannula is docked to cannula mount arm <NUM>, a controller of telescoping cannula mount system <NUM> inhibits unlocking of cannula mount arm <NUM> until cannula mount arm <NUM> can be safely retracted back into curved distal end portion 319D of link <NUM>.

The arm retraction system of telescoping cannula mount system <NUM> does not include an electrical motor to retract cannula mount arm <NUM>. The arm retraction system provides an automatic smooth controlled retraction of cannula mount arm <NUM> without extra motors without the extra electronics, and sensors required to safely implement a motorized axis. Thus, there is no possibility that an electrical short, an induced current, or any other source of electrical power can inadvertently cause such an electrical motor to move cannula mount arm <NUM> during a surgical procedure. The arm retraction system is referred to as a mechanical arm retraction system to indicate that the arm retraction system includes only mechanical components and no electrical components such as a motor, electronics or electrical components.

An electrical component, e.g., an electric actuator, in a latching/unlatching system is used to unlatch cannula mount arm <NUM> so that potential energy in the mechanical arm retraction system automatically retracts cannula mount arm <NUM>. As indicated above, the mechanism of mechanical arm retraction system is entirely mechanical and so there is no potential for an electrical problem affecting the operation of mechanical arm retraction system.

However, if the electrical component in the latching/unlatching system were inadvertently fired during a surgical procedure, the mechanical arm retraction system would retract cannula mount arm <NUM>. The normal fault recovery logic in a computer-assisted surgical system would not be able to compensate for such an inadvertent firing of the electrical component in the latching/unlatching system. Thus, in one aspect, the power to trigger this electrical component is shorted to ground during a surgical procedure. Consequently, use of the electrical component in the latching/unlatching system is inhibited during a surgical procedure. Any spurious voltage on the power line to the electrical component is also shorted to ground, and this assures that the electrical component cannot be fired during the surgical procedure, and so cannula mount arm <NUM> cannot be inadvertently retracted from the locked and extended position.

<FIG> are enlarged illustrations of curved distal end portion 319D of fourth link <NUM>. In <FIG>, arrow <NUM> shows the first and second directions used in the discussion of <FIG>. The proximal and distal directions are an example of a first direction and a second direction opposite to the first direction.

In particular, <FIG> is a perspective view of curved distal end portion 319D of fourth link <NUM>, sometimes referred to as link <NUM>, with curved cannula mount arm <NUM> retracted, e.g., parked. In the parked position, telescoping cannula mount system <NUM> has no stored potential energy that can move cannula mount arm <NUM>, and so telescoping cannula mount system <NUM> and cannula mount arm <NUM> are said to be in a zero energy state, which was referred to as the first state above. When cannula mount arm <NUM> is parked in curved distal end portion 319D of fourth link <NUM>, a portion of a first end <NUM>-<NUM> of cannula mount arm <NUM> extends from a distal face of curved distal end portion 319D of link <NUM>.

Cannula sterile adapter <NUM> is shown mounted on first end <NUM>-<NUM> of cannula mount arm <NUM>. In this example, cannula sterile adapter <NUM> includes an aperture <NUM> configured to receive an attachment portion <NUM> of cannula <NUM>. While it not shown in the drawings, cannula sterile adapter <NUM> typically is attached to a surgical drape to facilitate forming a boundary between a sterile region and a non-sterile region.

In this example, cannula <NUM> includes a bowl section <NUM> at a proximal end <NUM> of cannula <NUM>. A tube <NUM> extends in a distal direction from bowl section <NUM>. Attachment portion <NUM> is attached to bowl section <NUM>. Attachment portion <NUM> may include depressions <NUM> on opposite sides of attachment portion <NUM> to assist with mounting cannula <NUM> to a cannula mount assembly (see <FIG> and <FIG>) in the distal end, first end <NUM>-<NUM>, of cannula mount arm <NUM>. Depressions <NUM> are configured to facilitate docking of cannula <NUM> to cannula sterile adapter <NUM> and the cannula mount assembly. For examples of cannula <NUM> suitable for use with cannula mount arm <NUM>, see PCT International Publication No. <CIT>.

To attach cannula <NUM> to cannula mount arm <NUM>, cannula mount arm <NUM> must first be withdrawn from curved distal end portion 319D of distal link <NUM> and locked in an extended position, and then cannula <NUM> can be docked at the distal end of cannula mount arm <NUM>. Since telescoping cannula mount system <NUM> does not include any electrical motors, cannula mount arm <NUM> must be manually withdrawn from curved distal end portion 319D.

Thus, a person grasps first end <NUM>-<NUM> of cannula mount arm <NUM> and pulls cannula mount arm <NUM> from curved distal end portion 319D. The force used to pull cannula mount arm <NUM> from curved distal end portion 319D is stored by telescoping cannula mount system <NUM> as potential energy that can be used later to automatically retract cannula mount arm <NUM>. When cannula mount arm <NUM> is fully extended, cannula mount arm is locked in the extended position, as illustrated in <FIG>. When cannula mount arm <NUM> is locked in the extended position, e.g., locked in a second state of the arm, a cannula arm extended and locked signal is sent to the controller.

Cannula mount arm <NUM> includes a plurality of buttons. In one aspect, the plurality of buttons includes an arm retraction button <NUM>, a cannula release button <NUM>, and a clutch button <NUM>. If cannula <NUM> is not docked on cannula mount arm <NUM>, depressing arm retraction button <NUM> causes cannula mount arm <NUM> to be automatically retracted into curved distal end portion 319D of link <NUM>.

The shape of cannula mount arm <NUM> and the configuration of the plurality of buttons are selected so that when cannula mount arm <NUM> is retracted into curved distal end portion of link <NUM> while draped, it unlikely that drape will be snagged or caught on any of the plurality of buttons or any part of cannula mount arm <NUM>. This prevents a contaminated drape from being pulled inside curved distal end portion 319D of link <NUM> and potentially damaged. Thus, the interior of link <NUM> does not require sterilization before use in another surgical procedure.

In this aspect, a portion of cannula mount arm <NUM> has an oval shape and there are no abrupt changes in shape of cannula mount arm <NUM> on which a surgical drape could be caught. When it is said the cannula mount arm <NUM> has an oval shape, it means that in a cross-sectional view, the outer surface of cannula mount arm <NUM> has an oval shape.

In particular, edges of indentation <NUM> are sloped and curved so that the surgical drape slides over the edges of indentation <NUM> as cannula mount arm <NUM> is retracted. Similarly, a surface of arm retraction button <NUM> is flush with the outer surface of cannula mount arm <NUM>, when not depressed, so that there is no edge of arm retraction button <NUM> to snag the drape as the drape moves across arm retraction button <NUM>.

Cannula release button <NUM> has smooth edges and surfaces so that if the drape falls into indentation <NUM>, the drape moves smoothly around cannula release button <NUM> as cannula mount arm <NUM> retracts. The surface and curvature of clutch button <NUM> is similarly selected so that there are no edges or abrupt surface changes that could snag the drape as cannula mount arm <NUM> retracts.

If cannula <NUM> is not docketed on cannula mount arm <NUM>, the controller inhibits entering a following system mode of operation. In the following system mode of operation, sometimes referred to as following, motion of a slave surgical instrument follows motion of a master tool teleoperatively coupled to the slave surgical instrument.

To mount cannula <NUM> on cannula mount arm <NUM>, both cannula release button <NUM> and clutch button <NUM> are depressed simultaneously and held in the depressed position. Manipulator arm assembly <NUM> is moved, while clutched, to the location of attachment portion <NUM> of cannula <NUM>, and then attachment portion <NUM> is inserted into cannula sterile adapter <NUM> and into the distal end of cannula mount arm <NUM>. Then, cannula release button <NUM> and clutch button <NUM> are released and cannula <NUM> is latched to cannula mount arm <NUM>, which is now no longer clutched, but is now locked in place. In order to facilitate one-person docking, the two buttons <NUM> and <NUM> are positioned to allow operation with one hand, while the second hand can be used to hold cannula <NUM> in the proper orientation for docking.

In one aspect, there are sensors in the cannula mounting system that indicate when a cannula is docked to cannula mount arm <NUM>. When the controller receives a signal that a cannula is docked to cannula mount arm <NUM>, the controller disables the retraction of cannula mount arm <NUM>. The retraction of cannula mount arm <NUM> remains disabled until after cannula <NUM> is undocked from cannula mount arm <NUM>. Specifically, depressing arm retraction button <NUM> after cannula <NUM> is docked results in no action. Similarly, the controller cannot successfully command retraction of cannula mount arm <NUM> until after cannula <NUM> is undocked.

As explained more completely below, cannula release button <NUM> is purely mechanical, and if cannula release button <NUM> is depressed, cannula <NUM> will be free to be pulled out of the cannula mount assembly. The same thing is true in docking cannula <NUM>, if cannula release button <NUM> is depressed, cannula <NUM> can be positioned in the cannula mount assembly. Therefore, clutch button <NUM> does not always have to be pressed to dock cannula <NUM> - for example, if the cannula mount arm <NUM> could be clutched to the exact proper location, then cannula <NUM> could be docked using only cannula release button <NUM>. However, typically, both buttons <NUM> and <NUM> are activated simultaneously, because otherwise, it is hard to tell when cannula <NUM> and the cannula mount assembly are properly aligned.

<FIG> are cutaway illustrations of curved distal end portion 319D of link <NUM> to show cannula mount system <NUM> that includes mechanical arm retraction system <NUM> and a latching/unlatching system <NUM>. Mechanical arm retraction system <NUM> includes a constant force spring <NUM>-<NUM>, a pinion gear <NUM> coupled to a rotary damper <NUM> (<FIG>), and a curved segment gear <NUM>. Latching/unlatching system <NUM> includes a solenoid <NUM> and a locking assembly <NUM>. Solenoid <NUM> is an example of an electric actuator. In view of this disclosure, electric actuators other than a solenoid can be included in latching/unlatching system <NUM>.

When latch <NUM> is released by latching/unlatching system <NUM>, constant force spring <NUM>-<NUM> pulls cannula mount arm <NUM> in the second direction (the proximal direction in <FIG>), i.e., automatically retracts cannula mount arm <NUM> into curved distal end portion 319D of link <NUM>. However, the speed of the retraction is limited by rotary damper <NUM>, sometimes referred to as damper <NUM>. Pinion gear <NUM> rides on curved segment gear <NUM> and is coupled to cannula mount arm <NUM> by rotary damper <NUM>. Thus, as cannula mount arm <NUM> is moved in the second direction, pinion gear <NUM> rotates, but the speed of the rotation is limited by rotary damper <NUM>. This limits the speed that pinion gear <NUM> can move along curved segment gear <NUM>. Consequently, cannula mount arm <NUM> is automatically retracted into curved distal end portion 319D of link <NUM> in a controlled manner, without use of any electric motor, electronics, or sensors.

An anchor bracket <NUM> is rigidly affixed to the distal end of curved distal end portion 319D. A first end, e.g., a distal end, of curved segment gear <NUM> is fixedly attached to anchor bracket <NUM>. In this example, curved segment gear <NUM> is a curved rectangularshaped arm with a first curved surface <NUM>-<NUM> and a second curved surface <NUM>-<NUM> opposite and removed from first curved surface <NUM>-<NUM>. First curved surface <NUM>-<NUM> has a smaller radius of curvature than second curved surface <NUM>-<NUM>. Second curved surface <NUM>-<NUM> includes gear teeth <NUM> in this example. See <FIG> and <FIG> for a more detailed illustration of curved segment gear <NUM>.

In another aspect, the gear teeth of curved segment gear <NUM> could be on first curved surface <NUM>-<NUM> or on one of the other sides of curved segment gear <NUM>. Thus, the configuration of curved segment gear <NUM> in the drawings is optional and is not intended to be limiting to the specific configuration illustrated.

A spring assembly <NUM> includes a spring assembly bracket <NUM>-<NUM>, a spool assembly <NUM>-<NUM>, and a constant force spring <NUM>-<NUM>. A first end, e.g., a distal end, of spring assembly bracket <NUM>-<NUM> is fixedly attached to a second end, e.g., a proximal end, of curved segment gear <NUM>. Spool assembly <NUM>-<NUM> is mounted on a second end, e.g., a proximal end, of spring assembly bracket <NUM>-<NUM>. Constant force spring <NUM>-<NUM>, sometimes referred to as spring <NUM>-<NUM>, is a metal spring. A second end of spring <NUM>-<NUM> is coiled onto spool assembly <NUM>-<NUM> so that spring <NUM>-<NUM> winds and unwinds around spool assembly <NUM>-<NUM>. A first end of spring <NUM>-<NUM> is anchored to a second end <NUM>-<NUM>, e.g., a proximal end, of cannula mount arm <NUM>. Thus, as cannula mount arm <NUM> is withdrawn from curved distal end portion 319D, spring <NUM>-<NUM> is unwound from spool assembly <NUM>-<NUM>, and so stores potential energy.

Second end <NUM>-<NUM>, e.g., the proximal end, of cannula mount arm <NUM> includes a latch <NUM>. In one aspect, latch <NUM> is mounted on second end <NUM>-<NUM> of cannula mount arm <NUM>. In this aspect, latch <NUM> includes an inclined ramp that leads to a socket. (See <FIG>).

The electric actuator, e.g., solenoid <NUM>, in latching/unlatching system <NUM> is mounted on anchor bracket <NUM>. In this example, solenoid <NUM> is mounted on a second end of anchor bracket <NUM>, where the first end of anchor bracket <NUM> is attached to curved distal end portion 319D. The solenoid plunger is connected to a locking assembly <NUM> in latching/unlatching system <NUM>.

Locking assembly <NUM> engages latch <NUM> when cannula mount arm <NUM> is moved to the fully extended position as illustrated in <FIG>. To disengage locking assembly <NUM> from latch <NUM> so that spring <NUM>-<NUM> can retract curved cannula mount arm <NUM> into curved distal end portion 319D of link, solenoid <NUM> is activated, e.g., fired. As explained more completely below, when cannula mount arm <NUM> is locked in the extended position and cannula <NUM> is docked on cannula mount arm <NUM>, firing of solenoid <NUM> is inhibited, and so cannula mount arm <NUM> cannot be retracted when a cannula is docked to arm <NUM>.

<FIG> and <FIG> are opposing perspective side view of portions of telescoping cannula mount system <NUM>. <FIG> shows that in this aspect, first end of spring <NUM>-<NUM> is fixedly attached to second end <NUM>-<NUM> of cannula mount arm <NUM> at point <NUM>. Thus, <FIG> shows the first end of spring <NUM>-<NUM> both attached and unattached.

<FIG> also shows more clearly gear teeth <NUM> on second curved surface <NUM>-<NUM> of curved segment gear <NUM>. Curved segment gear <NUM> is attached to a curved rail <NUM> (<FIG>). A plurality of bearing blocks, which are attached to cannula mount arm <NUM>, ride on curved rail <NUM>. A curved rail and associated bearing blocks suitable for use in telescoping cannula mount system <NUM> are commercially available from THK America, Inc. , <NUM> East Commerce Drive, Schaumburg, IL.

Pinion gear <NUM> (<FIG> and <FIG>) is attached to a rotating shaft of damper <NUM> (<FIG>). The teeth on pinion gear <NUM> mesh with gear teeth <NUM> of curved segment gear <NUM>. Damper <NUM> is affixed to second end <NUM>-<NUM> of cannula mount arm <NUM>. Damper <NUM> provides no damping when cannula mount arm <NUM> is manually withdrawn, i.e., extended, from curved distal end portion 319D. Damper <NUM> provides damping as spring <NUM>-<NUM> automatically retracts cannula mount arm <NUM> into curved distal end portion 319D. The amount of damping is selected so that cannula mount arm does not suddenly snap back into curved distal end portion 319D, but retracts with a controlled safe speed with low impact at the end of travel.

<FIG> shows locking assembly <NUM> in more detail. A circuit board <NUM> (<FIG>) is attached to second end <NUM>-<NUM> of cannula mount arm <NUM>. Circuit board <NUM> is coupled to a latch sensor that is described below (see latch sensor <NUM> (<FIG>)), and to all other sensors and switches on cannula mount arm <NUM>. To provide power to the latch sensor and to transfer signals from the circuit board <NUM> back to the controller, ribbon cables <NUM> are connected to circuit board <NUM>. Ribbon cables <NUM> are an example of a rolling loop electrical cable. The use of more than one ribbon cable is optional. In some applications, a single ribbon cable could be used.

In this aspect, ribbon cables <NUM> are stacked beneath a cross-curve spring, i.e., are coupled to a spring. The cross-curve spring prevents ribbon cables <NUM> from buckling as the rolling loop formed by ribbon cables <NUM> deploys when cannula mount arm <NUM> moves into and out of curved distal end portion 319D. Thus, the electrical cable is coupled to a spring to prevent the electrical cable from buckling as the rolling loop formed by the electrical cable deploys The rolling loop formed by ribbon cables <NUM> is placed between two concentric trays <NUM> and <NUM>.

In one aspect, ribbon cables <NUM> include a first plurality of ribbon cables and a second plurality of ribbon cables. The first plurality of ribbon cables carry signals to and from cannula mount system <NUM> and provide power to cannula mount system <NUM>. The second plurality of ribbon cables form a ground bond between cannula mount arm <NUM> and link <NUM>.

First ends of the first plurality of ribbon cables are attached to first connectors <NUM> that mate with first circuit board <NUM> of cannula mount arm <NUM>. Second ends of the first plurality of ribbon cables are attached to a second circuit board within link <NUM> (the second circuit board is not shown). In one aspect, the second plurality of ribbon cables, e.g., two ribbon cables, is stacked beneath the first plurality of ribbons cables. The second plurality of ribbon cables is used as a ground bond between stationary link <NUM> and moving cannula mount arm <NUM>. The second plurality of ribbon cables runs between connectors <NUM> and <NUM>. Connector <NUM> is connected to cannula mount arm <NUM> and connector <NUM> is connected of second curved tray <NUM>. Curved tray <NUM> is coupled to anchor bracket <NUM>, and so is coupled to curved distal end portion 319D of link <NUM>.

Thus, telescoping cannula mount system <NUM> includes a first curved tray <NUM> and a second curved tray <NUM>. Second curved tray <NUM> is connected to the curved distal end portion 319D of link <NUM>. First curved tray <NUM> is connected to the proximal end of cannula mount arm <NUM>.

Rolling loop ribbon cables <NUM> are anchored between a first end <NUM>-<NUM>-a distal end-of second curved tray <NUM> and a first end-a distal end- of first curved tray <NUM>. A first portion of ribbon cables <NUM>, e.g., a first leg, follows the curve of first curved tray <NUM> and then ribbon cables <NUM> have a shape resembling a letter "U" on its side. The U-shape forms a transition to a second portion of ribbon cables <NUM>, e.g., a second leg that follows the curve of second curved tray <NUM>. Thus, ribbon cables <NUM> form an open loop with both legs of the loop being curved and the length of each leg changing as cannula mount arm <NUM> is withdrawn and as cannula mount arm <NUM> is retracted.

<FIG> and <FIG> are more detailed illustrations of locking assembly <NUM> and latch <NUM>. In this aspect, locking assembly <NUM> includes a first link <NUM>-<NUM>, a second link <NUM>-<NUM>, a latch link <NUM>-<NUM>, a spring <NUM>-<NUM>, a cam follower <NUM>-<NUM>, and a latch flag <NUM>-<NUM>.

First link <NUM>-<NUM> has a Y-shaped body. A second end of first link <NUM>-<NUM>, which forms the base leg of the Y-shape, is rotatably mounted on a first pin <NUM> extending from anchor bracket <NUM>. Thus, first link <NUM>-<NUM> is grounded to anchor bracket <NUM>. A pin <NUM> extends between two legs at a first end of first link <NUM>-<NUM>-the two legs forming the uprights of the Y-shape.

A plunger <NUM>-<NUM> of solenoid <NUM> is connected to pin <NUM>. In this aspect, solenoid <NUM> is a linear motion solenoid, and plunger has a slot in one end. The slot rides on pin <NUM>. A spring <NUM>-<NUM> around plunger <NUM>-<NUM> returns plunger <NUM>-<NUM> to the extended position after solenoid <NUM> is activated and then deactivated. Spring <NUM>-<NUM> and spring <NUM>-<NUM> work in the same direction, thus the forces of these two springs are additive.

A second end of second link <NUM>-<NUM> is rotatably mounted on pin <NUM>, i.e., second link <NUM>-<NUM> is rotatably connected to first link <NUM>-<NUM>. A first end of second link <NUM>-<NUM> is rotatably connected to a second end <NUM>-<NUM> of latch link <NUM>-<NUM>.

Latch link <NUM>-<NUM> is mounted on a second pin <NUM> that extends from anchor bracket <NUM> between first end <NUM>-<NUM> and second end <NUM>-<NUM>. Second pin <NUM> functions as a fulcrum (pivot point) for latch link <NUM>-<NUM>. Latch link <NUM>-<NUM> is grounded to anchor bracket <NUM> by second pin <NUM>. Cam follower <NUM>-<NUM> is affixed to a first side of a first end <NUM>-<NUM> of latch link <NUM>-<NUM>. Latch flag <NUM>-<NUM> is affixed to a second side of the first end <NUM>-<NUM> of latch link <NUM>-<NUM>. In this aspect, the first side and the second side of latch link <NUM>-<NUM> intersect to form one edge of latch link <NUM>-<NUM> that extends from the first end to the second end.

Thus, in this aspect, latch link <NUM>-<NUM> is implemented as a V-shaped lever with a first leg that extends from the pivot point to first end <NUM>-<NUM> and a second leg that extends from the pivot point to second end <NUM>-<NUM>. The first leg is longer than the second leg in this aspect.

In this example, latch link <NUM>-<NUM> is a Class <NUM> lever because the fulcrum is between the effort (the force supplied by solenoid <NUM>) and the load (cam follower <NUM>-<NUM> and latch flag <NUM>-<NUM>). While in this example, latch link <NUM>-<NUM> is implemented as a Class <NUM> lever, this is illustrative only and is not intended to be limiting. In other aspects, a Class <NUM> lever or a Class <NUM> lever could be used. For a Class <NUM> lever, the load is between the fulcrum and the effort, and for a Class <NUM> lever, the effort is between the fulcrum and the load.

A first end of spring <NUM>-<NUM> is connected to latch link <NUM>-<NUM> between first end <NUM>-<NUM> and the pivot point. A second end of spring <NUM>-<NUM> is connected to a third pin <NUM> extending from anchor bracket <NUM>. Spring <NUM>-<NUM> provides a force on the first leg of latch link <NUM>-<NUM> that pulls cam follower <NUM>-<NUM> into latch socket <NUM>-<NUM>.

For the configuration illustrated in <FIG>, cannula mount arm <NUM> is fully extended and latched in the extended position, as shown in <FIG> and <FIG>. To arrive at this position, cam follower <NUM>-<NUM> moves up inclined ramp <NUM>-<NUM> (<FIG>) of latch <NUM> as cannula mount arm <NUM> is withdrawn.

The forces on the first leg of latch link <NUM>-<NUM> provided by springs <NUM>-<NUM> and <NUM>-<NUM> maintains cam follower <NUM>-<NUM> on inclined ramp <NUM>-<NUM>. When cam follower <NUM>-<NUM> reaches the high end of inclined ramp <NUM>-<NUM> and cannula mount arm <NUM> is withdrawn further, springs <NUM>-<NUM> and <NUM>-<NUM> pull and hold cam follower <NUM>-<NUM> in socket <NUM>-<NUM> of latch <NUM>. As cam follower <NUM>-<NUM> is pulled into socket <NUM>-<NUM>, latch flag <NUM>-<NUM> is positioned in latch sensor <NUM>. In this aspect, latch sensor <NUM> includes a pair of photo-interrupt switches so that if latch flag <NUM>-<NUM> is positioned in latch sensor <NUM>, a light beam in each of the pair of photo-interrupt switches is broken. Breaking the light beams changes the state of the photo-interrupt switches, which is used to determine when cannula mount arm <NUM> is latched in the extended position. In this aspect, the pair of photo-interrupt switches is used for safety redundancy. If such redundancy is not needed, a single photo-interrupt switch could be used.

The use of a pair of photo-interrupt switches as a latch sensor is illustrative only and is not intended to be limiting. In other aspects, a capacitance switch or an inductive switch could be used. Alternatively, the latch mechanism could depress a switch that provides the cannula arm extended and locked signal.

When cannula mount arm <NUM> is locked in the extended position, to retract cannula mount arm <NUM> into curved distal end portion 391D, solenoid <NUM> is activated, sometime referred as being fired, either by depressing button <NUM> (<FIG>) or by the controller issuing a retract cannula mount arm command. When solenoid <NUM> is activated, solenoid <NUM> pulls plunger <NUM>-<NUM> linearly into the solenoid body, e.g., plunger <NUM>-<NUM> is moved proximally by activation of solenoid <NUM>. The force from a linear solenoid is highly non-uniform, with the greatest force being applied at the fully retracted (most proximal) and the force dropping off rapidly as the plunger extends (in the distal direction). The geometry of links <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> is designed to compensate for this nonlinearity of force, and to allow the solenoid to effectively lift cam follower <NUM>-<NUM> clear of latch <NUM>.

The motion of plunger <NUM>-<NUM> causes second link <NUM>-<NUM> to exert a force in a first direction-downward-on second end <NUM>-<NUM> of latch link <NUM>-<NUM>. The force in the first direction on second end <NUM>-<NUM> of latch link <NUM>-<NUM> causes latch link <NUM>-<NUM> to pivot about pin <NUM>, which moves first end <NUM>-<NUM> of latch link <NUM>-<NUM> in a second direction, opposite to the first direction-upward-and extends spring <NUM>-<NUM>. The motion of first end <NUM>-<NUM> of latch link <NUM>-<NUM> moves cam follower <NUM>-<NUM> out of socket <NUM>-<NUM> and above the highest point on inclined ramp <NUM>-<NUM>. Similarly, latch flag <NUM>-<NUM> is moved out of latch sensor <NUM>. Since cam follower <NUM>-<NUM> is no longer seated in latch <NUM>, spring <NUM>-<NUM> automatically retracts cannula mount arm <NUM> into curved distal end portion 319D. The speed of the retraction is controlled by damper <NUM> as pinion gear <NUM> moves along gear teeth <NUM> on curved segment gear <NUM>.

<FIG> is process flow diagram of acts used to control retraction of cannula mount arm <NUM>. The linear flow in <FIG> is used for ease of understanding only and is not intended to be limiting. The various processes in <FIG> might be performed in an order other than that illustrated by the linear flow, and could be perform simultaneously rather than sequentially.

Initially, a user accesses a user interface that includes a CONFIGURE FOR DRAPING <NUM> option. The user interface is generated by a controller in the computer-assisted surgical system that includes patient side support system <NUM>. It should be appreciated that the controller can be made up of one unit, or multiple different units. When the controller is divided up among different units, the units may be centralized in one location or distributed across the computer assisted surgical system. Also, the different units of the controller may be given names that characterize the acts controlled by that unit of the controller.

When the user selects CONFIGURE FOR DRAPING <NUM> option, the controller configures patient side support system <NUM> to facilitate draping patient side support system <NUM>. Here, only the acts related to controlling cannula mount arm <NUM> are considered in the configuring patient side support system <NUM> for draping.

In an ARM RETRACTED check process <NUM>, the controller determines whether cannula mount arm <NUM> is parked within curved distal end portion 319D of link <NUM>. If the signal from latch sensor <NUM> indicates cannula mount arm <NUM> is retracted in curved distal end portion 319D of link <NUM>, ARM RETRACTED check process <NUM> transfers to an INHIBIT FOLLOWING process <NUM>. Conversely, if the signal from latch sensor <NUM> indicates cannula mount arm <NUM> is not retracted in curved distal end portion 319D of link <NUM>, ARM RETRACTED check process <NUM> transfers to a RETRACT ARM process <NUM>. Note that a surgical system including patient side support system <NUM> typically has several features that are monitored to determine whether following is permitted or is inhibited. In <FIG>, only the actions associated with cannula mount system <NUM> are considered with respect to the inhibiting and permitting of following.

In RETRACT ARM process <NUM>, the controller first enables solenoid <NUM> and then activates solenoid <NUM>. As described above, when activated, solenoid <NUM> causes locking assembly <NUM> to lift cam follower <NUM>-<NUM> out of latch <NUM>, and consequently spring <NUM>-<NUM> automatically retracts cannula mount arm <NUM> into curved distal end portion 319D of link <NUM>. RETRACT ARM process <NUM> transfers to INHIBIT FOLLOWING process <NUM>. Thus, in this aspect, mechanical arm retraction system <NUM> is used to automatically change the shape of manipulator arm assembly <NUM> for draping.

When cannula mount arm <NUM> is parked in curved distal end portion 319D of link <NUM>, cannula <NUM> is not docked on cannula mount arm <NUM>. When cannula <NUM> is not docked, following is inhibited. Thus, in INHIBIT FOLLOWING process <NUM> following is inhibited based on a cannula not being docked. INHIBIT FOLLOWING process <NUM> transfers to ARM EXTENDED AND LOCKED check process <NUM>.

ARM EXTENDED AND LOCKED check process <NUM> determines whether cannula mount arm <NUM> has been withdrawn from curved distal end portion 319D of link <NUM> and is locked in the extended position. If the signal from latch sensor <NUM> indicates cannula mount arm <NUM> is not latched in the extended position, ARM EXTENDED AND LOCKED check process <NUM> takes no action. Conversely, if the signal from latch sensor <NUM> indicates cannula mount arm <NUM> is latched in the extended position, ARM EXTENDED AND LOCKED check process <NUM> transfers to a CANNULA DOCKED check process <NUM>. ARM EXTENDED AND LOCKED check process <NUM> should not be interpreted as requiring polling to determine whether cannula mount arm <NUM> is latched in the extended position. In one aspect, an event handler is used to detect an event that is fired when the signal from latch sensor <NUM> indicates cannula mount arm <NUM> is latched in the extended position.

Once cannula mount arm <NUM> is latched in the extended position, two events are of interest-a cannula is docked or a command to retract cannula mount arm <NUM> is issued. Thus, CANNULA DOCKED check process <NUM> determines whether a cannula has been mounted on extended cannula mount arm <NUM>. If a signal is not received that a cannula is docked on cannula mount arm <NUM>, CANNULA DOCKED check process <NUM> transfers to RETRACT ARM COMMAND check process <NUM>. Conversely, if a signal is received that a cannula is docked on cannula mount arm <NUM>, CANNULA DOCKED check process <NUM> transfers to FOLLOWING INHIBITED check process <NUM>.

RETRACT ARM COMMAND check process <NUM> determines whether a command to retract cannula mount arm <NUM> into curved distal end portion 319D has been received. A command to retract cannula mount arm <NUM> can be generated by the user depressing arm retraction button <NUM> or by the controller issuing the command. As indicated above, cannula mount arm <NUM> can only be automatically retracted when a cannula is not docked on cannula mount arm <NUM>. This condition is satisfied when processing transfers to RETRACT ARM COMMAND check process <NUM>. Thus, if RETRACT ARM COMMAND check process <NUM> receives a command to retract cannula mount arm <NUM>, RETRACT ARM COMMAND check process <NUM> transfers to RETRACT ARM process <NUM>, and otherwise returns to CANNULA DOCKED check process <NUM>.

The loop between RETRACT ARM process <NUM> and CANNULA DOCKED check process <NUM> should not be interpreted as requiring polling to determine whether a cannula was docked and whether a command to retract cannula mount arm <NUM> was received. In one aspect, an event handler is used to detect the appropriate conditions and to fire an appropriate event indicating the conditions detected.

After a cannula is first docked to cannula mount arm <NUM>, the inhibition of following due to a cannula not being docked is removed, and then the next event of interest is undocking of the cannula. As described previously, cannula mount arm <NUM> cannot be retracted so long as cannula <NUM> is docked on arm <NUM>.

Thus, FOLLOWING INHIBITED check process <NUM> determines whether following is inhibited because a cannula is not docked on cannula mount arm <NUM>. If a cannula is docked on cannula mount arm <NUM>, FOLLOWING INHIBITED check process <NUM> transfers to PERMIT FOLLOWING process <NUM>, which removes the inhabitation of following by cannula mount system <NUM>. If there is no cannula docked on cannula mount arm <NUM>, FOLLOWING INHIBITED check process <NUM> returns to CANNULA DOCKED check process <NUM>.

Note that even if cannula mount system <NUM> permits following, the controller may still inhibit following due to other conditions in the surgical system. PERMIT FOLLOWING process <NUM> considers only the state of cannula mount system <NUM> in determining whether to permit following and does not consider other factors that may be used to determine when the surgical system is actually permitted to enter following by the controller.

The loop between CANNULA DOCKED check process <NUM> and FOLLOWING INHIBITED check process <NUM> also should not be interpreted as requiring polling to determine whether a cannula was docked. In one aspect, an event handler is used to detect the appropriate conditions and to fire an appropriate event indicating the conditions detected.

Note that as long as a cannula is docked, a retract arm command is not acted upon, and so cannula mount arm <NUM> cannot be inadvertently retracted. During a surgical procedure, parts of one or more surgical instruments extend through cannula <NUM> into a patient. If cannula mount arm <NUM> were retracted while a cannula was docked, the inadvertent motion of the surgical instruments might harm the patient, and so the interlock on retraction is used to prevent retraction so long as a cannula is docked to arm <NUM>.

<FIG> is a block diagram of an interlock control system <NUM> that implements an interlock that prevents retraction of cannula mount arm <NUM> when a cannula is mounted on cannula mount arm <NUM>. An arm retraction controller <NUM>, sometimes referred to as controller <NUM> receives system status information <NUM> that includes whether a cannula is docked on cannula mount arm <NUM>. A voltage control line <NUM> is connected between arm retraction controller <NUM> and a solenoid driver <NUM>. A switch with current limiter circuit <NUM> is positioned between a supply voltage V+ (<NUM> volts in one aspect) and solenoid driver <NUM>. Solenoid driver <NUM> is an example of an electric actuator driver. A solenoid bus <NUM> connects solenoid driver <NUM> to solenoid <NUM> and to a bus dump circuit <NUM>. Solenoid bus <NUM> is an example of an electric actuator bus. Both solenoid <NUM> and bus dump circuit <NUM> are also connected to ground. An enable/disable line <NUM> connects arm retraction controller <NUM> to bus dump circuit <NUM>.

When status information <NUM> indicates that a cannula is not mounted on cannula mount arm <NUM> and includes an arm retraction command, arm retraction controller <NUM> first generates a disable signal on enable/disable line <NUM> to bus dump circuit <NUM>. The disable signal causes bus dump circuit <NUM> to open a connection, in bus dump circuit <NUM>, between solenoid bus <NUM> and ground. Thus, when the disable signal is on enable/disable line <NUM>, bus dump circuit <NUM> does not connect solenoid bus <NUM> to ground.

After the disable signal is activated on enable/disable line <NUM>, arm retraction controller <NUM> provides a pulse width modulation duty cycle signal on voltage control line <NUM> to solenoid driver <NUM>. The switch in switch with current limiter circuit <NUM> is normally closed and so supply voltage V+ is provided to solenoid driver <NUM>. In response to the pulse width modulation duty cycle on voltage control line <NUM>, solenoid driver <NUM> drives a series of pulses on solenoid bus <NUM>, which activates solenoid <NUM>. As described above, when solenoid <NUM> is activated, mechanical arm retraction system <NUM> is enabled and automatically retracts cannula mount arm <NUM>.

After a brief time (less than the watchdog time, but long enough to unlatch cannula mount arm <NUM>) controller <NUM> removes the pulse width modulation duty cycle signal on voltage control line <NUM> to solenoid driver <NUM>. In response, solenoid driver <NUM> stops driving pulses on solenoid bus <NUM>, which deactivates solenoid <NUM>.

When a disable signal is generated on enable/disable line <NUM> by arm retraction controller <NUM>, watchdog timer <NUM> is started. When watchdog timer <NUM> times out, the disable signal on enable/disable line to bus dump circuit <NUM> is changed to an enable signal. The enable signal causes bus dump circuit <NUM> to close a connection between solenoid bus <NUM> and ground in bus dump circuit <NUM>. Thus, when the enable signal is on enable/disable line <NUM>, bus dump circuit <NUM> connects solenoid bus <NUM> to ground.

Hence, bus dump circuit <NUM> operates as switch between solenoid bus <NUM> and ground, and the state of the switch-open or closed-is controlled by the signal on enable/disable line <NUM>. Normally, bus dump circuit <NUM> is always shorting solenoid bus <NUM> to ground so that solenoid <NUM> cannot be fired. This only changes when both a cannula not mounted signal and an arm retraction command are present at the same time in status information <NUM>.

As shown in <FIG>, bus dump circuit <NUM> and solenoid <NUM> are connected in parallel between solenoid bus <NUM> and ground. The resistance in bus dump circuit <NUM> between solenoid bus <NUM> and ground is significantly lower than the resistance in solenoid <NUM> between solenoid bus <NUM> and ground. Thus, when bus dump circuit <NUM> is enabled, a large majority of the current flows from solenoid bus <NUM> through bus dump circuit <NUM> to ground. The remaining current that flows through solenoid <NUM> is insufficient to fire solenoid <NUM>. Consequently, any voltage on solenoid bus <NUM> does not fire solenoid <NUM> when bus dump circuit <NUM> is enabled.

The logic in arm retraction controller <NUM> permits arm retraction controller <NUM> to generate a command on voltage control line <NUM> to fire solenoid <NUM> when both a cannula not mounted signal and an arm retraction command are present in status information <NUM>, as just described. However, it is possible that arm retraction controller <NUM> generates a spurious command on voltage control line <NUM> to fire solenoid <NUM>, or that there is a short between a power source-either in solenoid driver <NUM> or in the cabling-and solenoid bus <NUM>. In each of these cases, bus dump circuit <NUM> is configured to connect solenoid bus <NUM> to ground, and so the spurious voltage does not fire solenoid <NUM>.

If solenoid driver <NUM> unintentionally drives a voltage on solenoid bus <NUM> and thereby creates a large current through solenoid driver <NUM> and bus dump circuit <NUM>, the current limiter circuit in switch with current limiter circuit <NUM> automatically opens the switch in circuit <NUM>. Thus, when switch with current limiter circuit <NUM> detects an abnormal current draw, switch with current limiter circuit <NUM> disconnects the power to solenoid driver <NUM>. This assures that the power supply, the circuitry in solenoid driver <NUM>, and the circuitry in bus dump circuit <NUM> are not damaged by an excessive current draw.

If the switch in switch with current limiter circuit <NUM> fails open, solenoid <NUM> cannot be fired. This is a safe condition. If the switch in switch with current limiter circuit <NUM> fails closed, e.g., is shorted, this could defeat the safety system. Thus, each time the computer-assisted surgical system is powered on, the switch in switch with current limiter circuit <NUM> is tested to assure that the switch is not shorted.

If the switch in bus dump circuit <NUM> fails closed, e.g., shorted, this is a safe condition. If the switch in bus dump circuit <NUM> fails open, this could defeat the safety system. Thus, each time computer-assisted surgical system is powered on, the switch bus dump circuit <NUM> is tested to assure that the switch has not failed open.

In the event bus dump circuit <NUM> receives neither an enable command nor a disable command (possibly because of a broken connection on enable/disable line <NUM> or a failure in controller <NUM>), bus dump circuit <NUM> automatically enables itself. This is another safeguard to insure that cannula mount arm <NUM> cannot be inadvertently retracted.

In one aspect, arm retraction controller <NUM> is implemented using a field programmable gate array circuit. In this aspect, bus dump circuit <NUM> is implemented using a metal-oxide-semiconductor field-effect transistor with the gate connected to enable/disable line <NUM>.

<FIG> is a cut away drawing of first end <NUM>-<NUM> of cannula mount arm <NUM> to show a cannula mount assembly. The cannula mount assembly includes a cannula docking assembly <NUM>, a linkage assembly <NUM>, a cannula release button assembly <NUM>, and a linear motion assembly <NUM>. This cannula mount assembly can be implemented in cannula mount arms other than those illustrated in the drawings.

Cannula docking assembly <NUM> is coupled to a first end of cannula release button assembly <NUM> by linkage assembly <NUM>. A second end of cannula release button assembly <NUM> is coupled to linear motion assembly <NUM>. Linear motion assembly <NUM> constrains cannula release button assembly <NUM> to linear motion in third and fourth directions-down and up with respect to the outer surface of first end <NUM>-<NUM> of cannula mount arm <NUM>-as represented by arrow <NUM>. The range of motion of cannula release button assembly <NUM> along linear motion assembly <NUM> in the third direction is limited by a portion of cannula release button assembly <NUM> contacting a first hard stop within the housing of first end <NUM>-<NUM> of cannula mount arm <NUM>.

When a force is applied on cannula release button <NUM>, i.e., cannula release button <NUM> is depressed, cannula release button assembly <NUM> moves linearly in the third direction-down in this example-along linear motion assembly <NUM>. Linkage assembly <NUM> converts the linear motion of cannula release button assembly <NUM> in the third direction to linear motion, in the second direction, e.g., in the proximal direction, of a moveable block <NUM> (<FIG>) within cannula docking assembly <NUM>, and in so doing compresses a spring <NUM> in moveable block <NUM>. In one aspect, spring <NUM> is implemented using two springs.

Here, the second direction-in this example, in the proximal direction-is a direction that is different from the fourth direction that is opposite the third direction, e.g., the up direction is different from the proximal direction. In <FIG> the third direction is a down direction and the fourth direction is an up direction as represented by arrow <NUM>. The first direction is a distal direction and the second direction is a proximal direction as represent by arrow <NUM>. Thus, as stated, the second direction is different from the fourth direction that is opposite to the third direction and is different from the third direction.

Similarly, when the downward force on cannula release button <NUM> is released, spring <NUM> in cannula docking assembly <NUM> moves moveable block <NUM> linearly in the first direction-in the distal direction in this example-to a position where spring <NUM> has a minimum potential energy. Linkage assembly <NUM> coverts the linear motion of moveable block <NUM> in the first direction to linear motion of cannula release button assembly <NUM> in the fourth direction. Here, the first direction is in a direction that is different from the direction opposite the fourth direction. As pointed out above, the fourth direction is up in <FIG>, and the direction opposite the fourth direction is the third direction (down), which is different from the first direction (distal direction). Cannula release button assembly <NUM> is moved in the fourth direction by the force of spring <NUM> and held in a location such that cannula release button <NUM> is in its undepressed position, as illustrated in <FIG>, <FIG>, and <FIG>.

Cannula release button assembly <NUM> includes a frame <NUM>, cannula release button <NUM>, and rail <NUM>. Frame <NUM> includes a first end <NUM>-<NUM> and a second end <NUM>-<NUM>. A linear slide <NUM> of linear motion assembly <NUM> is affixed to second end <NUM>-<NUM> of frame <NUM>. Linear slide <NUM> is constrained to slide along rail <NUM> of linear motion assembly <NUM>. Rail <NUM> is mounted in first end <NUM>-<NUM> of frame <NUM>. Cannula release button <NUM> is mounted on frame <NUM> adjacent linear slide <NUM>.

Linkage assembly <NUM> includes a first link <NUM>, a second link <NUM>, and a cam follower <NUM>. A first end <NUM>-<NUM> of second link <NUM> is rotatably mounted on a pin extending from a housing <NUM> of cannula docking assembly <NUM>. Thus, second link <NUM> is grounded to housing <NUM> of cannula docking assembly <NUM>. Cam follower <NUM> is mounted on a second end <NUM>-<NUM> of second link <NUM>. Cam follower <NUM> rides within rail <NUM> in first end <NUM>-<NUM> of frame <NUM> of cannula release button assembly <NUM>. Cam follower <NUM> is constrained within rail <NUM> so that cam follower <NUM> can move in the first and second directions, but not in the third and fourth directions.

A second end <NUM>-<NUM> of first link <NUM> is rotatably connected to a pin mounted in second link <NUM>. The pin is located between first end <NUM>-<NUM> of second link <NUM> and second end <NUM>-<NUM> of second link <NUM>. A first end <NUM>-<NUM> of first link <NUM> is rotatably connected to a pin in moveable block <NUM> (<FIG>).

When cannula release button <NUM> is depressed, second link <NUM> functions as a lever with a fulcrum provided by the pin extending from housing <NUM>. The effort is applied to second end <NUM>-<NUM> and the load is located between the fulcrum and second end <NUM>-<NUM>. In this example, when cannula release button <NUM> is depressed, second link <NUM> is a Class <NUM> lever because the load is between the fulcrum and the effort.

When cannula release button is released, second link <NUM> still functions as a lever with a fulcrum provided by the pin extending from housing <NUM>. The load is at the second end <NUM>-<NUM> and the effort is located between the fulcrum and second end <NUM>-<NUM>. In this example, when cannula release button <NUM> is released, second link <NUM> is a Class <NUM> lever because the effort is between the fulcrum and the load. Thus, second link <NUM> functions as both a Class <NUM> lever and a Class <NUM> lever. The class of lever is dependent on the direction that cannula release button <NUM> moves.

Thus, a force supplied by a user to depress cannula button <NUM> moves frame <NUM>, and consequently linear slide <NUM> moves along rail <NUM>. As frame <NUM> moves down, cam follower <NUM> moves in the second direction. As second end <NUM>-<NUM> of link <NUM> moves in the second direction, link <NUM> pivots about the pin in housing <NUM>. This motion moves first link <NUM> in the second direction and in third direction. The motion of link <NUM> moves moveable block <NUM> in the second direction, which compresses spring <NUM> in cannula docking assembly <NUM>, which releases a pair of clamping arms <NUM> in cannula docking assembly <NUM> so that pair of clamping arms <NUM> can be opened.

When the force on cannula button <NUM> is released, spring <NUM> expands and moves moveable block <NUM> in the first direction, which closes the pair of clamping arms <NUM>. As moveable block <NUM> moves in the first direction, first end <NUM>-<NUM> of first link <NUM> is moved in the first direction. The motion of first link <NUM> in the first direction causes second link <NUM> to pivot about the pin in housing <NUM>. Hence, second end <NUM>-<NUM> of second link <NUM> moves in the first direction and in the fourth direction as a result of moveable block <NUM> moving in the first direction. The motion of second end <NUM>-<NUM> of link <NUM> is transferred to frame <NUM> of assembly <NUM>, which linearly moves cannula release button <NUM> in the fourth direction until the motion of slide <NUM> is stopped by a second hard stop within the housing of first end <NUM>-<NUM> of cannula mount arm <NUM>.

The parts of cannula docking assembly <NUM> needed to understand the operation of cannula release button <NUM> are shown in more detail in <FIG>. Cannula docking assembly <NUM> includes a pair of clamping arms <NUM> to engage cannula <NUM>. For example, when attachment portion <NUM> of cannula <NUM> is inserted into aperture <NUM> of cannula docking assembly <NUM>, tips of clamping arms <NUM> latch to depressions of cannula sterile adapter <NUM> that in turn are compressed by clamping arms <NUM> into depressions <NUM> of attachment portion <NUM> to dock cannula <NUM> to cannula docking assembly <NUM>.

While it is not shown in <FIG> and <FIG>, each of clamping arms <NUM> pivots about a pin to facilitate mounting and releasing cannula <NUM>. Clamping arms <NUM> are actuated by moveable block <NUM> that engages and moves clamping arms <NUM> into a closed (latched) position to dock cannula <NUM>. For example, moveable block <NUM> includes a cam surface that engages each of clamping arms <NUM> to cause clamping arms <NUM> to pivot to the closed position.

Spring <NUM> biases moveable block <NUM> to the position that closes each of clamping arms <NUM>. Spring <NUM> is positioned between a mounting block <NUM> and moveable block <NUM>.

Cannula docking assembly <NUM> includes a sensor to detect the position of moveable block <NUM> to infer whether clamping arms <NUM> are in a locked or released position, as determined by the position of the cam surface on block <NUM> relative to clamping arms <NUM>. The sensor, for example, may be a switch that moveable block <NUM> contacts as moveable block <NUM> is actuated back and forth to actuate clamping arms <NUM>. Output from the sensor is transmitted to the controller of the computer-assisted surgical system to provide feedback, for example, whether clamping arms <NUM> are in a locked or released position. More details on a moveable block, clamping arms, and springs suitable for use in cannula docking assembly <NUM> are presented in PCT International Publication No. <CIT>.

Much of the previous discussion, including discussion associated with <FIG>, <FIG>, <FIG>, <FIG>, etc. refer to a patient side support system <NUM> with a manipulator arm assembly <NUM> having four links <NUM>, <NUM>, <NUM>, <NUM> coupled by rotary joints. A telescoping cannula mount system <NUM> comprises a curved cannula mount arm <NUM> that can be extended from or parked within a curved distal end portion 319D of the fourth link <NUM>.

Other designs of patient side support systems, manipulator arm assemblies, and shapes of telescoping cannula arm systems are contemplated and can be utilized in various embodiments. As some specific examples, <FIG> shows a schematic of a patient side support system <NUM> that may be implemented with any appropriate number of links and active or passive joints (seven links <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, six rotary joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and no prismatic joints are shown in <FIG>). A telescoping cannula mount system <NUM> comprises a cannula mount arm <NUM> that can be extended from or parked within a distal end portion 1219D of the link <NUM>. A cannula <NUM> can be mounted to the cannula mount arm <NUM>, and an instrument can be <NUM> extended through the cannula <NUM> to perform operations, as shown in <FIG>.

Parts of patient side support system <NUM> are analogous to corresponding parts in patient side support systems <NUM> and <NUM>. For example, in various embodiments, links <NUM>, <NUM>, <NUM>, <NUM> are analogous to links <NUM>, <NUM>, <NUM>, <NUM> of patient side support systems <NUM> and links <NUM>, <NUM>, <NUM>, <NUM> patient side support systems <NUM>. Thus, the description associated with the earlier figures is not repeated here for Fig. 1x2.

The cannula mount system <NUM> is shown as curved in <FIG> for convenience, and can be any appropriate shape with any number of linear and nonlinear segments in various embodiments. <FIG> shows some example telescoping cannula mount systems with different linear shapes that can be used with the patient side support system of <FIG>. Cannula mount arm <NUM> extends and retracts along the main axis of the link <NUM>, as shown by the dotted-line arrow <NUM>. Cannula mount arm <NUM> extends and retracts along an axis perpendicular to the main axis of <NUM>, as shown by the dotted-line arrow <NUM>. Cannula mount arm <NUM> extends and retracts along an axis angled with respect to the main axis of link <NUM>, as shown by the dotted-line arrow <NUM>.

Although a controller is described above, it is to be appreciated that such a controller may be implemented in practice by any number of modules and each module may include any combination of components. Each module and each component may include hardware, software that is executed on a processor, and firmware, or any combination of the three. Also, the functions and acts of controller, as described herein, may be performed by one module, or divided up among different modules or even among different components of a module. When divided up among different modules or components, the modules or components may be centralized in one location or distributed across the computer-assisted surgical system for distributed processing purposes. Thus, references to the controller should not be interpreted as requiring a single physical entity as in some aspects the controller is distributed across the computer-assisted surgical system.

As used herein, "first," "second," "third, " etc. are adjectives used to distinguish between different components or elements. Thus, "first," "second," and "third" are not intended to imply any ordering of the components or elements or to imply any total number of components or elements.

The above description and the accompanying drawings that illustrate aspects and embodiments of the present inventions should not be taken as limiting-the claims define the protected inventions. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the scope of this description and the claims. In some instances, well-known circuits, structures, and techniques have not been shown or described in detail to avoid obscuring the invention.

Further, this description's terminology is not intended to limit the invention. For example, spatially relative terms-such as "beneath", "below", "lower", "above", "upper", "proximal", "distal", and the like-may be used to describe one element's or feature's relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e., locations) and orientations (i.e., rotational placements) of the device in use or operation in addition to the position and orientation shown in the figures. For example, if the device in the figures were turned over, elements described as "below" or "beneath" other elements or features would then be "above" or "over" the other elements or features. Thus, the exemplary term "below" can encompass both positions and orientations of above and below. Likewise, descriptions of movement along and around various axes include various special device positions and orientations.

The singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context indicates otherwise. The terms "comprises", "comprising", "includes", and the like specify the presence of stated features, steps, operations, elements, and/or components but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups. Components described as coupled may be electrically or mechanically directly coupled, or they may be indirectly coupled via one or more intermediate components.

All examples and illustrative references are non-limiting and should not be used to limit the claims to specific implementations and embodiments described herein and their equivalents. Any headings are solely for formatting and should not be used to limit the subject matter in any way, because text under one heading may cross reference or apply to text under one or more headings. Finally, in view of this disclosure, particular features described in relation to one aspect or embodiment may be applied to other disclosed aspects or embodiments of the invention, even though not specifically shown in the drawings or described in the text.

Embodiments described above illustrate but do not limit the disclosure. It should also be understood that numerous modifications and variations are possible in accordance with the principles of the present disclosure. For example, in many aspects the devices described herein are used as single-port devices; i.e., all components necessary to complete a surgical procedure enter the body via a single entry port. In some aspects, however, multiple devices and ports may be used.

Claim 1:
A surgical system (<NUM>) comprising:
a curved link (<NUM>) of a manipulator arm (<NUM>), the curved link (<NUM>) having an end (319D);
a telescoping cannula mount assembly (<NUM>) positioned in the end (319D) of the curved link (<NUM>), the telescoping cannula mount assembly (<NUM>) including a curved cannula mount arm (<NUM>);
wherein:
in a first state, the curved cannula mount arm (<NUM>) is parked within the end (319D) of the curved link (<NUM>);
in a second state, the curved cannula mount arm (<NUM>) is locked in an extended position from the end (319D) of the curved link (319D);
the curved cannula mount arm (<NUM>) is configured to be manually moved from the first state to the second state; and
a force used to move the curved cannula mount arm (<NUM>) from the first state to the second state is stored as potential energy in a mechanical arm retraction system (<NUM>).