Patent Publication Number: US-2020282570-A1

Title: Surgical system with variable entry guide configurations

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/327,322 (filed Jan. 18, 2017)(entitled “Surgical System with Variable Entry Guide Configurations”), which is a U.S. national phase of International Application No. PCT/US2015/044757 (filed Aug. 12, 2015)(entitled “A Surgical System With Variable Entry Guide Configurations”), which designated the U.S. and which claims priority to and the benefit of:
         U.S. Patent Application No. 62/038,096, (filed Aug. 15, 2014)(entitled “Surgical System With Variable Entry Guide Configurations”); and   U.S. Patent Application No. 62/038,106, (filed Aug. 15, 2014)(entitled “Entry Guide Manipulator with a Roll System and An Instrument Manipulator Positioning System”), each of which is incorporated herein by reference in its entirety.       

    
    
     BACKGROUND 
     Field of Invention 
     The present invention relates generally to surgical instruments, and more particularly to positioning of surgical instruments. 
     Description of Related Art 
     Surgical systems, such as those employed for minimally invasive medical procedures, can include large and complex equipment to precisely control and drive relatively small tools or instruments.  FIG. 1A  illustrates an example of a known teleoperated controlled system  100 . System  100 , which may, for example, be part of a da Vinci® Surgical System commercialized by Intuitive Surgical, Inc., includes a patient-side cart  110  having multiple arms  130 . Each arm  130  has a docking port  140  that generally includes a drive system with a mechanical interface for mounting and providing mechanical power for operation of an instrument  150 . Arms  130  can be used during a medical procedure to move and position respective medical instruments  150  for the procedure. 
       FIG. 1B  shows a bottom view of a known instrument  150 . Instrument  150  generally includes a transmission or backend mechanism  152 , a main tube  154  extending from the backend mechanism  152 , and a functional tip  156  at the distal end of main tube  154 . Tip  156  generally includes a medical tool such as scissors, forceps, or a cauterizing instrument that can be used during a medical procedure. Drive cables or tendons  155  are connected to tip  156  and extend through main tube  154  to backend mechanism  152 . Backend mechanism  152  typically provides a mechanical coupling between the drive tendons  155  of instrument  150  and motorized axes of the mechanical interface of a docking port  140 . In particular, gears or disks  153  engage features on the mechanical interface of a docking port  140 . Instruments  150  of system  100  can be interchanged by removing one instrument  150  from a drive system  140  and then installing another instrument  150  in place of the instrument removed. 
     SUMMARY 
     A surgical system includes a single entry port, which may be used in a wide variety of different surgical procedures. The variety of surgical procedures uses various combinations of instruments that enter a patient through the single entry port. The instruments, in one aspect, are grouped into sets of instruments based on the shaft characteristics of the instruments, e.g., standard surgical instruments (graspers, retractors, scissors, cautery, and the like), advanced surgical instruments (staplers, vessel sealers, and the like) that may have a cross section larger than standard surgical instruments or unique cross sections, and camera instruments (visible, infrared, ultrasound, and the like) that also may have a cross section larger than standard surgical instruments or unique cross sections. These instruments can be manually controlled, controlled with computer assistance (fully or cooperatively controlled), or teleoperatively controlled. 
     The different surgeries that can be performed using at least one entry port may be performed on different regions of the body. For example, one surgery may be performed through the mouth of a patient; another surgery may be performed between the ribs of a patient; and other surgeries may be performed through other natural or incision orifices of a patient. Not only is the surgical system configured to use a variety of instruments, but also the surgical system is configured to use a variety of different entry guides, which guide the instruments into the patient toward the surgical site. At least a portion of each instrument is inserted through a corresponding channel in an entry guide. Typically, a different entry guide is used for each different type of surgery. The entry guide selected for a particular surgical procedure may maintain an insufflation seal, if necessary, and entry guide supports the shafts of the instruments at the entry point into the body of the patient. 
     To insert multiple instruments into a patient through a single entry port may require one or more of the shafts of the instruments to bend between where the shaft is connected to the housing of the instrument and the point where the shaft contacts a channel of the entry guide. This bend may be permanently pre-formed in a rigid instrument, such as a camera instrument, or may happen non-permanently when inserting the shaft of an instrument into a channel of the entry guide. If the shaft of the instrument is bent too much, the shaft of the instrument may be damaged and/or the instrument may not perform properly during the surgery. 
     An entry guide manipulator controls the position and orientation of an entry guide. The entry guide includes two or more channels. Each channel receives a surgical instrument and guides the surgical instrument toward the surgical site. Thus, two or more instruments are guided toward the surgical site via a single opening (port) in the body. An entry guide channel may be configured to receive an individual instrument type, such as a camera with an oval cross section. Or, an entry guide channel may be configured to receive many instrument types, such as therapeutic instruments with round cross sections. Various combinations of entry guide channel configurations may be used. The entry guide manipulator also controls the position and orientation of the instruments that extend through the entry guide channels. Thus, in one aspect, each entire instrument is positioned by the entry guide manipulator so that when the instrument&#39;s shaft is inserted in the channel of the entry guide, any bending of the shaft is not permanent and does not inhibit proper operation of the instrument such as for insertion/withdrawal or roll (if applicable). This positioning assures that any bending does not damage the instrument, and that any bending does not affect the correct operation of the instrument. Various entry guide channel arrangements may be used, each arrangement being associated with a different single entry port area in a patient. For example, an entry guide may have a circular cross section with its channels arranged generally equally spaced within the cross section. As a second example, an entry guide may have an oblong cross section with its channels arranged generally in a line. Therefore, in one aspect, for each entry guide with a different channel configuration, each instrument is positioned so that stresses induced by any bend in the shaft remain within a predetermined stress profile for the individual instrument, i.e., the stress on the shaft is controlled such that the shaft does not yield and permanently change shape. Additionally, the stress is maintained so that as the shaft rolls in the entry guide or is inserted and withdrawn through the entry guide, the cycling stress does not fatigue and break the shaft. This cycling stress load is a consideration associated with instrument life. And so, an individual instrument type is placed at a first location for entry into a corresponding channel in a first entry guide configuration, and the individual instrument type is placed at a different, second location for entry into a corresponding channel in a second entry guide configuration. 
     In one aspect, the entry guide manipulator simultaneously positions instrument mount interfaces for the instruments with respect to the channels in an entry guide so that when the shafts of the instruments are inserted into channels in the entry guide, any bending of the instrument shafts does not damage the instruments and does not inhibit operation of the instruments. If an instrument shaft is bent to the point that the shaft does not return to its original shape when withdrawn from the entry guide, the instrument is considered damaged. The entry guide manipulator is configured to make these position adjustments for each entry guide in a family of entry guides, and in one aspect, the position adjustments for the entire instrument is made with little or no user input. 
     In addition, the instrument manipulator positioning system eliminates the need for surgical procedure-specific instruments. In other words, the instrument manipulator positioning system allows use of a common set of instruments with a variety of entry guides by moving the instrument shafts as appropriate for use of each of the entry guides. 
     A surgical system includes an entry guide. In one aspect, the entry guide has a first channel and a second channel. The surgical system also includes a first instrument with a first shaft, and a second instrument with a second shaft. A manipulator in the system is coupled to the first and second instruments. 
     The manipulator includes an instrument manipulator positioning system. The instrument manipulator positioning system is configured to move a first instrument mount interface for the first instrument and to move a second instrument mount interface for the second instrument so that a first shaft of a first instrument is positioned for insertion into the first channel of the entry guide, and so that a second shaft of a second instrument is positioned for insertion into the second channel of the entry guide. Thus, the movement of the two interfaces by the instrument manipulator positioning system effectively aligns the two shafts with the corresponding channels in the entry guide. In one aspect, the first and second instrument mount interfaces are moved before the first and second instruments are mounted on the respective interfaces. While two instruments are used as an example, in one aspect, the instrument manipulator positioning system can position any combination of a desired number of instruments so that shafts of the instruments can be inserted into corresponding channels in an entry guide. 
     As used herein, “align” does not require that a lengthwise axis of a channel and a lengthwise axis of the shaft be coincident. Rather, “align” means that the shaft is in position for entry into the channel without damage, and that the entry may require a non-permanent bend in the shaft. In some instances, however, the lengthwise axis of one or more instrument shafts and one or more corresponding entry guide channels are truly coincident, and so no shaft bending occurs. Thus in a first positioning state of two or more instruments, the instruments are positioned so that their shafts each enter, without bending, corresponding channels of a first entry guide arranged in a first configuration, and in a second positioning state of the two or more instruments, the instruments are positioned so that their shafts each enter, without bending, corresponding channels of a second entry guide arranged in a second configuration. Optionally, in the second positioning state of the two or more instruments, the instruments are positioned so that one or more of the instrument shafts bend as the shafts enter a corresponding channel of the second entry guide arranged in the second configuration. Thus, for various positioning states of the instruments with reference to corresponding entry guide configurations, various combinations of shaft bending or non-bending are made as needed, based on the instrument shafts and the entry guide channel configurations. 
     In one aspect, the instrument manipulator positioning system includes an adjustment gear that is coupled to each of the first instrument mount interface for the first instrument and the second instrument mount interface for the second instrument. In one aspect, movement of the adjustment gear simultaneously moves the first and second instrument mount interfaces into the positions where insertion of the shafts into the first and second channels is possible without damaging the instruments, e.g., the shafts of the first and second instruments are sufficiently aligned with the first and second channels, respectively, when the first and second instruments are mounted on the first and second instrument mount interfaces, respectively. In a further aspect, the instrument manipulator positioning system also includes a manually operated knob coupled to the adjustment gear. A user turns the knob which in turn causes the adjustment gear to rotate and move the instruments coupled to the adjustment gear. Again, the use of two instrument mount interfaces is an example and is not intended to be limiting. In general, the adjustment gear can be coupled to a number of instrument mount interfaces necessary to move instruments into a proper position for use with an entry guide of interest, e.g., four instrument mount interfaces. 
     In yet another aspect, a user manually moves each instrument mount interface of a plurality of instrument mount interfaces, as needed, in a direction perpendicular to a lengthwise axis of an entry guide to a proper location. A pin may be used to lock each instrument mount interface in the desired location. In some situations, not all of the plurality of instrument mount interfaces may need to be moved. The proper location for a particular instrument mount interface can be determined by a location of a through hole in a disk of the instrument manipulator positioning system, for example. Alternatively, the proper location can be determined by allowing the instrument mount interface to move to a location which minimizes any bend in the shaft of the instrument mounted to the instrument mount interface after the shaft is inserted into the entry guide with the lengthwise axis of the entry guide being vertical. 
     In yet another aspect, the instrument manipulator positioning system includes a first plurality of motors and a second plurality of motors. Each plurality of motors is coupled to a different instrument mount interface. Each plurality of motors positions the corresponding instrument mount interface for the instrument so that when the instrument is mounted on the instrument mount interface, the shaft of the instrument is aligned with a channel in an entry guide, e.g., the shaft can be positioned in the channel. 
     In still another aspect, the instrument manipulator positioning system further includes a first gearbox coupled to the first instrument, and a second gearbox coupled to the second instrument. A gear is coupled to the first and second gearboxes. As the gear is moved, the movement of the gear causes the first and second gearboxes to simultaneously move the first and second instrument mount interfaces into the positions where insertion of the shafts into the first and second channels is possible without damaging the instruments. In one aspect the gear is a roll gear, and another aspect the gear is an adjustment gear. 
     In one aspect, the first gearbox includes a gear having a side surface. A pin is coupled to the side surface of the gear. In one aspect, the pin has one degree of freedom. The pin is coupled to the instrument mount interface so that as the pin moves, the first instrument mount interface moves, and consequently a distal end of the shaft is effectively moved in the same arc as the pin. Here, “effectively moved” means that even though the entire instrument may not be mounted to the instrument mount interface when the instrument mount interface moves, when the entire instrument is mounted to the instrument mount interface, the location of the shaft relative to the entry guide has been moved compared to the location of the shaft relative to the entry guide if the instrument had been mounted before the instrument mount interface was moved. 
     In another aspect, the second gearbox includes a gear having a side surface. A pin is coupled to the side surface of the gear. The side surface of the gear of the second gearbox includes a cam. The pin rides on the cam. In one aspect, the pin has one degree of freedom, and in another aspect, the pin has two degrees of freedom. The pin is coupled to the second instrument mount interface so that as the pin moves, the second instrument mount interface moves, and consequently a distal end of the shaft of the second instrument is effectively moved with the same motion as the pin. 
     In yet another aspect, the entry guide includes first identification information and the first instrument includes second identification information. The apparatus includes a control system configured to receive the first identification information and to receive the second identification information. The control system configures the apparatus based on the first identification information, in one aspect. 
     An apparatus includes a first entry guide having a first channel configuration and a second entry guide having a second channel configuration. The first channel configuration is different from the second channel configuration. 
     The apparatus also includes a surgical system. Only one of the first entry guide and the second entry guide is mounted in the surgical system during a surgical procedure. 
     The surgical system includes an instrument having a shaft. An instrument manipulator positioning system is coupled to the instrument. Based on the channel configuration of the entry guide mounted in the surgical system, the instrument manipulator positioning system moves the instrument to a predetermined location to align the shaft with a channel of the entry guide, e.g., positions the shaft to enable insertion of the shaft into the channel of the entry guide. The predetermined location maintains bending stress on the shaft within a predetermined stress profile, in one aspect. 
     Since multiple entry guides with different channel configurations can be used in the surgical system, the instrument manipulator positioning system of the entry guide manipulator is configured to move a plurality of instrument mount interfaces to enable insertion of shafts of a first plurality of instruments into a first entry guide having a first channel configuration. The instrument manipulator positioning system is also configured to move the plurality of instrument mount interfaces to enable insertion of shafts of a second plurality of instruments into a second entry guide having a second channel configuration. The second channel configuration is different from the first channel configuration. The first plurality of instruments can be either the same as or different from the second plurality of instruments. 
     In one aspect, a method includes an instrument manipulator positioning system simultaneously moving a first instrument manipulator and a second instrument manipulator so that if a first instrument is mounted to the first instrument manipulator, a shaft of the first instrument is aligned with a first channel in a first entry guide, and so that if a second instrument is mounted to the second instrument manipulator, a shaft of the second instrument is aligned with a second channel of the first entry guide. The method also includes the instrument manipulator positioning system simultaneously moving the first instrument manipulator and the second instrument manipulator so that if a third instrument is mounted to the first instrument manipulator, a shaft of the third surgical instrument is aligned with a first channel in a second entry guide, and so that if a fourth instrument is mounted to the second instrument manipulator a shaft of the fourth instrument is aligned with a second channel of the second entry guide. A channel configuration of the first entry guide is different from a channel configuration of the second entry guide, and the first entry guide and the second single guide are used at different times. 
     In another aspect, a method includes moving an entry guide having a lengthwise axis so that the lengthwise axis is vertical. Then, a shaft of a surgical device assembly is inserted into a channel of the entry guide, and the entire surgical device assembly is allowed to move to a position of least energy. Finally, the surgical device assembly is locked to a disk. 
     In one aspect, the first entry guide has a circular cross section, and the second entry guide has a non-circular cross section. One or both of the first and second entry guides can include a manual instrument channel. 
     The apparatus also includes a first camera instrument having a first shaft with a first bend at a first location. The first camera instrument is mounted in the surgical system when the first entry guide is mounted in surgical system. A second camera instrument has a second shaft with a second bend at second location. The second camera instrument is mounted in the surgical system when the second entry guide is mounted in the surgical system. The first location is different from the second location. 
     In one aspect, a kit of entry guides includes a plurality of entry guides. Each entry guide includes a plurality of channels. A channel configuration of each entry guide is different from a channel configuration in each of the other entry guides in the plurality of entry guides. Each entry guide in the plurality is separately mountable in a same surgical system. 
     In one aspect, a first guide in the plurality includes a camera channel and a plurality of surgical instrument channels. A second entry guide in the plurality includes a camera channel and a manual instrument channel. 
     In another aspect, a first entry guide in the plurality includes a camera channel and a plurality of surgical instrument channels. A second entry guide in the plurality includes a camera channel and an advanced surgical instrument channel. 
     In still another aspect, a first entry guide includes a circular cross section. A second entry guide includes a non-circular cross section. 
     In still yet another aspect, a first entry guide in the plurality includes a camera channel and a plurality of surgical instrument channels. A second entry guide in the plurality has an oblong-shaped cross section. The oblong shape has a major axis. The second entry guide includes a camera channel having a first lengthwise axis, a first surgical instrument channel having a second lengthwise axis, and a second surgical instrument channel comprising a third lengthwise axis. A lengthwise axis extends from a proximal end of a channel to a distal end of the channel. The first, second, and third lengthwise axes intersect the major axis of the oblong cross section of the second entry guide. 
     In still a further aspect, a first entry guide in the plurality includes a camera channel and a plurality of surgical instrument channels. A second entry guide in the plurality includes a camera channel. The camera channel has an oblong-shaped cross section. The oblong-shaped cross section has a major axis and a minor axis. The second entry guide also includes a first surgical instrument channel having a first lengthwise axis, a second surgical instrument channel having a second lengthwise axis, and a third surgical instrument channel having a third lengthwise axis. The first lengthwise axis and the second lengthwise axis intersect a first line extending from the major axis. The first line includes the major axis. The third lengthwise axis intersects a second line extending from the minor axis. The second line includes the minor axis. The major axis is perpendicular to the minor axis, and so the first line is perpendicular to the second line. 
     The surgical system includes a manipulator system. The manipulator system includes a roll system couplable to first and second surgical device assemblies. The roll system is configured to roll the entire first and second surgical device assemblies as a group. The manipulator system also includes an instrument manipulator positioning system coupled to the roll system and couplable to the first and second surgical device assemblies. The instrument manipulator positioning system is configured to position first and second instrument interface assemblies for the first and second surgical device assemblies to enable insertion of shafts of the first and second surgical device assemblies into different channels of an entry guide. 
     The instrument manipulator positioning system includes an adjustment gear, and the roll system includes a roll ring gear. The manipulator system also includes a drive assembly. The drive assembly is coupled to the roll ring gear and coupled to the adjustment ring gear. The drive assembly is configured to differentially rotate the adjustment gear and the roll ring gear to cause the instrument manipulator positioning system to move the first and second instrument interface mounts for the surgical device assemblies to enable insertion of shafts of the surgical device assemblies into respective channels of an entry guide. 
     In one aspect, the drive assembly is configured to hold the roll ring gear stationary and is configured to turn the adjustment gear while the roll ring gear is held stationary. In another aspect, the drive assembly is configured to hold the adjustment gear stationary and is configured to turn the roll ring gear while the adjustment gear is held stationary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is an illustration of a portion of a prior art surgical system. 
         FIG. 1B  is an illustration of a prior art surgical device assembly. 
         FIG. 2A  is a schematic illustration of an instrument manipulator positioning system and a plurality of surgical device assemblies coupled to the instrument manipulator positioning system. 
         FIG. 2B  is a schematic illustration of an instrument manipulator positioning system and a plurality of instrument manipulators before instruments have been coupled to the plurality of instrument manipulators. 
         FIG. 2C  is a schematic side view that illustrates aspects of a surgical system that includes an entry guide manipulator with an instrument manipulator positioning system. 
         FIG. 2D  illustrates trajectories implemented in the instrument manipulator positioning system of  FIG. 2C . 
         FIG. 2E  is an illustration of a surgical system that includes an entry guide manipulator configured to position instruments so that when the shafts of the instruments enter an entry guide, any bending of the shafts does not damage the instruments. 
         FIGS. 3A and 3B  are more detailed illustrations of the configuration of the surgical device assemblies in  FIG. 2E . 
         FIG. 4A  illustrates a manipulator assembly affixed to an insertion assembly that in turn is attached to a base assembly. 
         FIG. 4B  is a more detailed illustration of the instruments of  FIGS. 2A, 2C, 2E, 3A and 3B . 
         FIG. 5A  is a schematic representation of four base assemblies mounted on the entry guide manipulator. 
         FIG. 5B  is a cross sectional view of a first entry guide that is referred to as a standard entry guide. 
         FIG. 5C  is a cross sectional view of a second entry guide. 
         FIG. 5D  shows the first entry guide overlaid on the second entry guide. 
         FIG. 5E  illustrates the result of the instrument manipulator positioning system in the entry guide manipulator moving the positioning element that is coupled to a surgical instrument. 
         FIG. 5F  illustrates a plurality of, base assemblies having a hexagonal shape that could be mounted on and moved by the entry guide manipulator. 
         FIG. 6A  is an illustration of one implementation of an instrument manipulator positioning system in the entry guide manipulator. 
         FIG. 6B  is a cross-sectional view of an entry guide with at least one canted channel. 
         FIG. 6C  is an illustration of another implementation of an instrument manipulator positioning system in the entry guide manipulator. 
         FIGS. 7A to 7C  are a top, bottom, and oblique views respectively of one aspect of a portion of a base assembly that includes a floating platform. 
         FIG. 7D  is a cut-away illustration of one aspect of a positioning element receptacle assembly. 
         FIGS. 8A, 8B, and 8C  are other examples of the instrument manipulator positioning system of  FIGS. 2A and 2B  that can be included in the entry guide manipulator of  FIG. 2C  and in the entry guide manipulator of  FIG. 2E . 
         FIG. 8D  is yet another example of the instrument manipulator positioning system of  FIGS. 2A and 2B  that can be included in the entry guide manipulator of  FIG. 2C  and in the entry guide manipulator of  FIG. 2E . 
         FIG. 8E  is still another example of the instrument manipulator positioning system of  FIGS. 2A and 2B  that can be included in the entry guide manipulator of  FIG. 2C  and in the entry guide manipulator of  FIG. 2E . 
         FIG. 9  illustrates yet another example of an instrument manipulator positioning system. 
         FIGS. 10A and 10B  are proximal and distal views of a circular motion gearbox in a first set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIGS. 10C and 10D  are proximal and distal views of a linear motion gearbox in the first set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIGS. 11A and 11B  are proximal and distal views of a first gearbox in a second set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIGS. 11C and 11D  are proximal and distal views of a second gearbox in the second set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIGS. 11E and 11F  are proximal views of a third gearbox in the second set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIG. 11G  is a distal view of the third gearbox in the second set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIG. 11H  is a cross-sectional view of the third gearbox in the second set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIGS. 11I and 11J  are proximal and distal views of a fourth gearbox in the second set of gearboxes for the instrument manipulator positioning system of  FIG. 9 . 
         FIG. 11K  is a more detailed illustration of the cam gear of  FIG. 11J . 
         FIGS. 12A to 12D  illustrate one aspect of an entry guide manipulator including an instrument manipulator positioning system. 
         FIGS. 13A to 13D  illustrate an alternative aspect of an entry guide manipulator including an instrument manipulator positioning system. 
         FIGS. 14A to 14J  are illustrations of cross-sections of a family of entry guides that can be used with the systems of  FIGS. 2A, 2C, and 2E . 
         FIG. 15  is a process flow diagram of a method used to determine the range of motion required and the trajectory to be implemented in each of the four gearboxes in  FIG. 9  for the family of entry guides in  FIGS. 14A to 14J . 
         FIG. 16A  is a schematic representation of base assemblies mounted on the entry guide manipulator and the coordinate system used by the instrument manipulator positioning system. 
         FIG. 16B  is a schematic representation of a surgical instrument with a shaft that is entering an entry guide mounted in a cannula, where the shaft is bent against the entry guide. 
         FIG. 16C  is a schematic top view of three surgical instruments mounted as illustrated in  FIGS. 3A and 3B . 
         FIG. 17  illustrates acceptable stress regions for each positioning element and the associated entry guide channel showing the allowable offsets from ideal (minimum stress) instrument shaft positions. 
         FIG. 18A  illustrates the surgical instrument and camera instrument trajectories and ranges of motion of gearboxes in  FIG. 9  for the family of entry guides in  FIGS. 14A to 14J . 
         FIG. 18B  illustrates the seven locations for the instrument manipulator associated with the gearbox of  FIGS. 11A and 11B . 
         FIG. 18C  illustrates the seven locations of the output pin in the slot of  FIG. 11B . 
         FIG. 18D  illustrates the seven locations for the instrument manipulator associated with the gearbox of  FIGS. 11C and 11D . 
         FIG. 18E  illustrates the seven locations of the output pin in the slot of  FIG. 11D . 
         FIG. 18F  illustrates the seven locations for the instrument manipulator associated with the gearbox of  FIGS. 11E to 11H . 
         FIG. 18G  illustrates the seven locations of the output pin in the slot of  FIG. 11G . 
         FIG. 18H  illustrates the seven locations for the instrument manipulator associated with the gearbox of  FIGS. 11I to 11J . 
         FIG. 18I  illustrates the seven locations of the output pin in the slot of  FIG. 11J . 
         FIGS. 19A and 19B  are schematic illustrations of camera instruments having a pre-bent shaft. 
         FIG. 20A  is a schematic illustration of one aspect of a control system in the surgical system of  FIG. 2E . 
         FIG. 20B  is a process flow diagram of one aspect of a method performed by the instrument manipulator positioning system compatibility module of  FIG. 20A . 
         FIGS. 21A and 21B  are side views illustrating a first example of a way to attach base assemblies to a portion of the entry guide manipulator. 
         FIG. 22A  is a side view illustrating a second example of a way to attach base assemblies to a portion of the entry guide manipulator. 
         FIGS. 22B and 22C  are top views of the second example of  FIG. 22A . 
         FIGS. 23A and 23B  are side views illustrating a third example of a way to attach base assemblies to a portion of the entry guide manipulator. 
     
    
    
     In the drawings, for single digit figure numbers, the first digit in the reference numeral of an element is the number of the figure in which that element first appears. For double-digit figure numbers, the first two digits in the reference numeral of an element is the number of the figure in which that element first appears. 
     DETAILED DESCRIPTION 
     A surgical system, e.g., a teleoperated, computer-assisted surgical system, with a single entry port is used in a wide variety of different surgeries. The variety of surgical procedures uses various combinations of instruments that enter a patient through the single entry port. The instruments, in one aspect, are grouped into sets of instruments based on the shaft characteristics of the instruments, e.g., standard surgical instruments, advanced surgical instruments, and camera instruments. These instruments can be manually controlled, controlled with computer assistance (fully or cooperatively controlled), or teleoperatively controlled. 
     The different surgeries that can be performed using the single entry port may be performed on different regions of the body. For example, one surgery may be performed through the mouth of a patient; another surgery may be performed between the ribs of a patient; and other surgeries may be performed through other orifices of a patient or through an incision in the patient. Not only is the surgical system configured to use a variety of instruments, but also the surgical system is configured to use a variety of different entry guides. Typically, a different entry guide is used for each different type of surgery. The entry guide selected for a particular surgical procedure may maintain an insufflation seal, if necessary, and the entry guide supports the shafts of the instruments at the entry point into the body of the patient. 
     A single entry port means that a single incision in a patient or a single bodily orifice of the patient is used to perform the surgical procedure. While a single entry port surgical system is used as an example, this example is not intended to limit the aspects described below to surgical systems that utilize a single entry port. The aspects described below can be used in any surgical system that inserts multiple instruments into a patient through a single entry guide. For example, if a surgical system utilizes two or more entry ports into a patient, and an entry guide having a plurality of channels is used in any of or all of the two or more entry ports, the aspects described below are directly applicable to such a surgical system. 
       FIG. 2A  is a schematic illustration of a plurality of surgical device assemblies in a surgical system. A first surgical device assembly includes a first instrument manipulator  240 A 1  and a first instrument  260 A 1 . First instrument  260 A 1  is mounted to first instrument manipulator  240 A 1 . First instrument  260 A 1  includes a shaft  262 A 1  that extends in a distal direction from a body of first instrument  260 A 1 . The surgical device assembly including first instrument  260 A 1  is coupled to an instrument manipulator positioning system  231 A by a first longitudinal motion mechanism  233 A 1 . Longitudinal motion mechanism  233 A 1  moves the first surgical device assembly in a proximal direction and in a distal direction. A second surgical device assembly includes a second instrument manipulator  240 A 2  and a second instrument  260 A 2 . Second instrument  260 A 2  is mounted to second instrument manipulator  240 A 2 . Second instrument  260 A 2  includes a shaft  262 A 2  that extends in a distal direction from a body of second instrument  260 A 2 . The second surgical device assembly including second instrument  260 A 2  is coupled to instrument manipulator positioning system  231 A 2  by a second longitudinal motion mechanism  233 A 2 . Longitudinal motion mechanism  233 A 2  moves the second surgical device assembly in a proximal direction and in a distal direction. 
     To insert multiple instruments  260 A 1 ,  260 A 2  into a patient through a single entry port may require one or more of shafts  262 A 1 ,  262 A 2  of instruments  260 A 1 ,  260 A 2  to bend between where the shaft is connected to the body of the instrument and the point where the shaft contacts a channel of the entry guide  270 A. If the shaft of the instrument is bent too much, the shaft of the instrument may be damaged and/or the instrument may not perform properly during the surgery. 
     Thus, in one aspect, each entire instrument  260 A 1 ,  260 A 2  ( FIG. 2A ) is positioned by an instrument manipulator positioning system  231 A, which in some aspects is part of an entry guide manipulator, so that when each shaft  262 A 1 ,  262 A 2  is inserted in a corresponding channel of entry guide  270 A, any bending of the shaft is not permanent and does not inhibit proper operation of the instrument. This assures that any bending does not damage the instrument and that any bending does not affect the correct operation of the instrument. 
     In one aspect, for each entry guide with a different channel configuration, instrument manipulator positioning system  231 A moves at least one instrument mount interface  240 A 1 _IMI for an instrument  260 A 1  so that stresses induced by any bend in shaft  262 A 1  remains within a predetermined stress profile, e.g., the stress on shaft  262 A 1  is controlled such that shaft  262 A 1  does not yield and permanently change shape. Additionally, the stress is maintained so that as shaft  262 A 1  rolls in entry guide  270 A, the cycling stress does not fatigue and break shaft  262 A 1 . This cycling stress load can be a consideration associated with instrument life. 
     In one aspect, each instrument mount interface is configured to couple an instrument to an instrument manipulator and to support that instrument while coupled. For example, a first instrument mount interface  240 A 1 _IMI supports instrument  260 A 1  and couples instrument  260 A 1  to instrument manipulator  240 A 1 , and a second instrument mount interface  240 A 2 _IMI supports instrument  260 A 2  and couples instrument  260 A 2  to instrument manipulator  240 A 2 . 
     For a first entry guide having a first channel configuration, instrument manipulator positioning system  231 A has a first state, and for a second entry guide having a second channel configuration, instrument manipulator positioning system  231 A has a second state. The first channel configuration is different from the second channel configuration. 
     In the first state, instrument manipulator positioning system  231 A moves instrument mount interface  240 A 1 _IMI, by moving longitudinal motion mechanism  233 A 1  and consequently instrument manipulator  240 A 1 , so that when instrument  260 A 1  is mounted on instrument mount interface  240 A 1 _IMI, a distal end  263 A 1  of shaft  262 A 1  is aligned with a corresponding channel in the first channel configuration. 
     In the second state, instrument manipulator positioning system  231 A moves instrument mount interface  240 A 1 _IMI so that when instrument  260 A 1  is mounted on instrument mount interface  240 A 1 _IMI, a distal end  263 A 1  of shaft  262 A 1  is aligned with a corresponding channel in the second channel configuration. If in either the first state or the second state, the shaft is bent upon passing through entry guide  270 A, the shaft is aligned with the corresponding channel in the entry guide prior to passing though entry guide  270 A so that any bending does not damage the instrument and does not inhibit proper operation of the instrument. Here, the corresponding channel in the channel configuration is the channel through which the shaft passes. 
     Thus, in the first state, at least a portion of instrument mount interface  240 A 1 _IMI is at a first location in a plane  286 B ( FIG. 2B ). Plane  286 B is perpendicular to a longitudinal axis  285 A of entry guide  270 A. In the second state, the portion of instrument mount interface  240 A 1 _IMI is moved to a second location in plane  286 B, where the second location is different from the first location. Note that when the portion of instrument mount interface  240 A 1 _IMI moves in plane  286 B, a portion of instrument manipulator  240 A 1  also moves in a plane that is parallel to plane  286 B. 
     Numerous examples are presented below of aspects of instrument manipulator positioning system  231 A that move one or more instrument mount interfaces in a plane that is perpendicular to the longitudinal axis of the entry guide. The movement, in one aspect, is in one dimension of plane  286 B and in other aspects, the movement is in two dimensions of plane  286 B. Each aspect described below of an instrument manipulator positioning system has at least one of the two states described here, and each aspect illustrates a different way to implement the or each of the two states. In addition, instrument manipulator positioning system  231 A can be implemented having manual control of the movement of the instrument mount interfaces or having automatic control of the movement of the instrument mount interfaces. 
     In one aspect, instrument manipulator positioning system  231 A simultaneously moves instrument interface mounts  240 A 1 _IMI,  240 A 2 _IMI for instruments  260 A 1 ,  260 A 2  with respect to the channels in entry guide  270 A, if necessary, so that when shafts  262 A 1 ,  262 A 2  of instruments  260 A 1 ,  260 A 2  are passed through channels of entry guide  270 , any bending of instrument shafts  262 A 1 ,  262 A 2  does not damage the instruments and does not inhibit operation of instruments  260 A 1 ,  260 A 2 . As explained above, in some instance, a shaft of an instrument may pass through a channel of the entry guide without any bending. If an instrument shaft is bent to the point that the shaft does not return to its original shape when withdrawn from entry guide  270 , the instrument is considered damaged. In this aspect, instrument manipulator positioning system  231 A is configured to move each instrument mount interface as required for each entry guide in a family of entry guides, and in one aspect, the adjustment is made with little or no user input. 
     In one aspect, instrument manipulator positioning system  231 A moves instrument mount interfaces  240 A 1 _IMI  240 A 2 _IMI, as needed, before instruments  260 A 1 ,  260 A 2  are mounted on instrument manipulator positioning system  231 A. In one aspect, instrument manipulator positioning system  231 A is one integral system. In another aspect, there is an individual instrument manipulator positioning system  231 A for each instrument. Irrespective of the implementation of system  231 A, the operation is as described herein. 
     As described above, instrument manipulator positioning system  231 A is configured to move a first instrument mount interface  240 A 1 _IMI for first instrument  260 A 1  and to move second instrument mount interface  240 A 1 _IMI for the second instrument  260 A 2  in a plane  286 B so that first shaft  262 A 1  is positioned for insertion into a first channel of entry guide  270 A, and so that second shaft  262 A 2  is positioned for insertion into a second channel of entry guide  270 A. The first and second channels are different channels. Thus, the movement of the two interfaces by instrument manipulator positioning system  231 A effectively aligns the two shafts, e.g., aligns the distal end of the two shafts, with the corresponding channels in entry guide  270 A. 
     As used herein, “align” does not require that a lengthwise axis of a channel and a lengthwise axis of the shaft be coincident. Rather, “align” means that the shaft is in position for entry into the channel without damage and that the entry may require a non-permanent bend in the shaft. In some instances, however, the lengthwise axis of one or more instrument shafts and one or more corresponding entry guide channels are truly coincident, and so no shaft bending occurs. Thus, in a first positioning state of two or more instruments, the instruments are positioned so that their shafts each enter, without bending, corresponding channels of a first entry guide arranged in a first configuration, and in a second positioning state of the two or more instruments, the instruments are positioned so that their shafts each enter, without bending, corresponding channels of a second entry guide arranged in a second configuration. Optionally, in the second positioning state of the two or more instruments, the instruments are positioned so that one or more of the instrument shafts bend as the shafts enter a corresponding channel of the second entry guide arranged in the second configuration. Thus, for various positioning states of the instruments with reference to corresponding entry guide configurations, various combinations of shaft bending or non-bending are made as needed, based on the instrument shafts and the entry guide channel configurations. 
     In one aspect described below, instrument manipulator positioning system  231 A includes an adjustment gear that is coupled to each of the first instrument mount interface for the first instrument and the second mount interface for the second instrument. In one aspect, movement of the adjustment gear simultaneously moves the first and second instrument mount interfaces into the positions where insertion of the shafts into the first and second channels is possible without damaging the instruments, e.g., the shafts of the first and second instruments are aligned with the first and second channels, respectively when the first and second instruments are mounted on the first and second instrument mount interfaces, respectively. In a further aspect, instrument manipulator positioning system  231 A also includes a manually operated knob coupled to the adjustment gear. A user turns the knob which in turn causes the adjustment gear to rotate and move the surgical instruments coupled to the adjustment gear. Alternatively, a user manually moves each instrument mount interface to the proper location and uses a pin to lock the instrument mount interface in that location, for example the instrument manipulator is locked to a disk in instrument manipulator positioning system  231 A. 
     In one aspect, instrument manipulator positioning system  231 A, sometimes referred to as system  231 A, includes a plurality of movable platforms, one for each of a plurality of instruments that are coupled to system  231 A. In one aspect, each moveable platform is connected to a longitudinal motion mechanism, e.g., a first moveable platform is coupled to longitudinal motion mechanism  233 A 1  and a second movable platform is coupled to longitudinal motion mechanism  233 A 2 . Various examples of movable platforms are presented below. 
     Each longitudinal motion mechanism is connected to an instrument manipulator assembly, e.g., longitudinal motion mechanism  233 A 1  is connected to instrument manipulator assembly  240 A 1 , and longitudinal motion mechanism  233 A 2  is connected to instrument manipulator assembly  240 A 2 . Each longitudinal motion mechanism moves the connected instrument manipulator assembly in a proximal direction and in a distal direction, e.g. in a first direction and a second direction along an extended lengthwise axis  285 A of entry guide  270 A. 
     Each instrument manipulator assembly includes an instrument manipulator interface on a distal face of the instrument manipulator assembly, in one aspect. Each instrument manipulator assembly also includes a plurality of motors that drive elements of an instrument attached to the instrument manipulator interface. 
     In one aspect, instrument manipulator positioning system  231 A includes a lateral motion mechanism. The lateral motion mechanism is coupled to each of the movable platforms, i.e., coupled to each of the plurality of instrument manipulator assemblies, e.g., instrument manipulator assembly  240 A 1  and instrument manipulator assembly  240 A 2 . The lateral motion mechanism moves the plurality of instrument manipulator assemblies in plane  286 B, i.e., the lateral motion mechanism moves an instrument manipulator assembly in a plane that is perpendicular to the direction of motion, as represented by arrow  290 , provided by a longitudinal motion mechanism. Various examples of the lateral motion mechanism are described below. Thus, a lateral motion mechanism causes an instrument mount interface to be moved laterally, i.e., in a direction perpendicular to extended lengthwise axis  285 A, sometimes referred to as lengthwise axis  285 A, of entry guide  270 A. In one aspect, the lateral motion is motion in a plane perpendicular to extended lengthwise axis  285 A. 
       FIG. 2C  is a schematic side view that illustrates aspects of a surgical system  200 C that uses aspects of instruments, surgical device assemblies, and manipulation and control systems described herein. The three main components are an endoscopic imaging system  292 , a surgeon&#39;s console  294  (master), and a patient side support system  210 C (slave), all interconnected by wired (electrical or optical) or wireless connections  296 . One or more electronic data processors may be variously located in these main components to provide system functionality. Examples are disclosed in U.S. patent application Ser. No. 11/762,165, which is incorporated by reference herein. 
     Patient side support system  210 C includes an entry guide manipulator  230 C. At least one surgical device assembly is coupled to entry guide manipulator  230 C. Each surgical device assembly includes either a surgical instrument or a camera instrument. For example, in  FIG. 2C , one surgical device assembly includes an instrument  260 C 1  with a shaft  262 C 2  that extends through entry guide  270 C during a surgical procedure. 
     Entry guide manipulator  230 C includes, as described more completely below, an instrument manipulator positioning system  231 C, sometimes referred to as positioning system  231 C or system  231 C. Positioning system  231 C moves a portion of each of the instrument mount interfaces in a plane so that when each of the instruments is coupled to entry guide manipulator  230 C using the instrument mount interfaces, each of the shafts of the instruments is aligned for insertion into one of the channels in entry guide  270 C. Typically, entry guide  270 C includes a plurality of channels. Thus, instrument manipulator positioning system  231 C effectively moves the shafts of the instruments by moving each instrument in a plurality of instruments, as needed, to align each of the shafts for entry into a channel in a particular entry guide channel configuration. 
     Thus, in one aspect, an instrument mount interface is moved so that when an instrument is attached to that instrument mount interface, a shaft of the instrument is properly aligned with a channel in an entry guide used in the surgical procedure. In another aspect, the instrument is mounted on the instrument mount interface, and then the instrument mount interface is moved. The movement of the instrument mount interfaces moves the entire instrument so that the shaft of the instrument is properly aligned with the channel in the entry guide used in the surgical procedure. Consequently, the movement of the instrument mount interface is the same irrespective of whether the instrument is mounted before or after the movement of the instrument mount interface. 
     In one aspect, positioning elements of instrument manipulator positioning system  231 C, e.g., positioning elements of a lateral motion mechanism of system  231 C, move in a plane to simultaneously move the instrument mount interfaces and consequently move each instrument to the appropriate location for entry of that instrument&#39;s shaft into entry guide  270 C. The path of the movement in the plane, sometimes called a trajectory, can be, for example, an arc, a straight line, a meandering combination of arcs, or some combination of curved paths and lines. Thus, the trajectory can have either one degree of freedom or two degrees of freedom. The plane is perpendicular to the lengthwise axis of entry guide  270 C, in one aspect. Thus, in this aspect, each of the trajectories is in a plane perpendicular to the lengthwise axis, sometimes referred to as the longitudinal axis, of entry guide  270 C See  FIG. 2D  for examples of typical trajectories  226 ,  227 ,  228 , and  229 . 
     As a positioning element moves along a trajectory, the instrument mount interface is moved along the same trajectory, and effectively a distal tip of a shaft of an instrument coupled to the instrument mount interface moves along the same trajectory. Thus, motion of the positioning element causes the shaft to be moved to a location where the shaft is aligned with a channel in entry guide  270 C. In this position, the shaft can enter and pass through the channel in entry guide  270 C without damaging the instrument and without inhibiting operation of the instrument. The particular paths implemented in instrument manipulator positioning system  231 C depend at least in part on the types of surgical device assemblies that can be mounted on system  231 C and/or the configuration of channels in entry guide  270 C. 
     As explained more completely below, different entry guides are used in different surgical procedures. An entry guide that enters the body through the ribs typically has a different shape than an entry guide that enters the body through an incision in the abdomen. The different shapes of the entry guides require different layouts of the channels that extend through the entry guides, i.e., different channel configurations. 
     Also, the shapes and/or sizes of the shafts of the instruments may be different for different instruments. An entry guide is used that accommodates the shapes and sizes of the shafts of the instruments used in a particular surgical procedure. The trajectories, such as those illustrated in  FIG. 2D , are designed to accommodate a set of entry guides that can be used with patent side support system  210 C. 
     When an entry guide, such as entry guide  270 C, is mounted on entry guide manipulator  230 C, and an instrument, e.g., instrument  260 C 1 , is mounted on entry guide manipulator  230 C, a control system determines whether shaft  262 C 1  of instrument  260 C 1  can be, or has been, aligned by instrument manipulator positioning system  231 C with a channel in entry guide  270 C. If instrument manipulator positioning system  231 C cannot properly align shaft  262 C 1 , an alarm is activated and the system rejects instrument  260 C 1 . 
     Instrument manipulator positioning system  231 C can properly align shaft  262 C 1  if system  231 C can move the instrument mount interface and consequently the entire surgical device assembly to a location so that when shaft  262 C 1  passes through the corresponding channel in entry guide  270 C, instrument  260 C 1  is not damaged. Typically, instrument  260 C 1  not being damaged means that shaft  262 C 1  is not bent to the point that the shaft is damaged, e.g., permanently bent, and/or that operation of elements passing though shaft  262 C 1  is not hindered during operation of instrument  260 C 1 . 
     In one aspect, at least one of the surgical device assemblies in plurality of surgical device assemblies  280 C includes a shaft with a portion that is rigid, but this rigid portion can be resiliently bent between entry guide  270 C and the proximal end of the shaft. Arrow  290  defines the distal and proximal directions. In one aspect, each surgical device assembly in plurality of surgical device assemblies  280 C is positioned by instrument manipulator positioning system  231 C to maintain the bending stress or stresses on the instrument shaft within a predetermined stress profile. This assures that the instrument shaft and thus the instrument is not damaged by the bending, e.g., the stress on the shaft is controlled such that the shaft does not yield and permanently change shape. Additionally, the stress is maintained so that as the shaft rolls in entry guide  270 C, the cycling stress does not fatigue and break the shaft. 
     The ability to individually position an instrument, and hence its shaft, with respect to a channel in an entry guide by moving an instrument mount interface provides versatility to patient side support system  210 C. For example, this ability allows entry guides with different channel configurations to be used in system  210 C. In addition, the instrument manipulator positioning system eliminates the need for surgical procedure specific instruments. In other words, the instrument manipulator positioning system allows use of a common set of instruments with a variety of entry guides by moving the instrument shafts around, as described herein. 
     Prior to considering entry guide manipulator  230 C with instrument manipulator positioning system  231 C in further detail, other aspects of system  200 C are described. Imaging system  292  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  292  outputs processed image data (e.g., images of the surgical site, as well as relevant control and patient information) to a surgeon at surgeon&#39;s console  294 . 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&#39;s console  294  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  294  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&#39;s hands working behind/below the display screen. These aspects are discussed more fully in U.S. Pat. No. 6,671,581, which is incorporated by reference herein. 
     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. In some aspects the master position may be made proportional to the insertion velocity to avoid using a large master workspace. Alternatively, the surgeon may clutch and declutch the masters to use a ratcheting action for insertion. In some aspects, insertion may be controlled manually (e.g., by hand operated wheels), and automated insertion (e.g., servomotor driven rollers) is then done when the distal end of the surgical device assembly is near the surgical site. Preoperative or real time image data (e.g., MRI, X-ray) of the patient&#39;s anatomical structures and spaces available for insertion trajectories may be used to assist insertion. 
     Patient side support system  210 C includes a floor-mounted base  201 C, or alternately a ceiling mounted base (not shown). Base  201 C may be movable or fixed (e.g., to the floor, ceiling, wall, or other equipment such as an operating table). 
     Base  201 C supports an arm assembly that includes a passive, uncontrolled setup arm assembly  220 C and an actively controlled manipulator arm assembly  230 C. The actively controlled manipulator arm assembly  230 C is referred to as entry guide manipulator  230 C. 
     In one example, the setup portion includes a first setup link  202 C and two passive rotational setup joints  203 C and  205 C. Rotational setup joints  203 C and  205 C allow manual positioning of the coupled setup links  204 C and  206 C if the joint brakes for setup joints  203 C and  205 C 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  203 C and  205 C and setup links  204 C and  206 C allow a person to place entry guide manipulator  230 C at various positions and orientations in Cartesian x, y, z space. A passive prismatic setup joint (not shown) between link  202 C of arm assembly  220 C and base  201 C may be used for large vertical adjustments  212 C. 
     Remote center of motion  246 C is the 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). As described in more detail below, 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&#39;s console  294 . 
     As shown in  FIG. 2C , a manipulator assembly yaw joint  211 C is coupled between an end of setup link  206 C and a first end, e.g., a proximal end, of a first manipulator link  213 C. Yaw joint  211 C allows first manipulator link  213 C to move with reference to link  206 C in a motion that may be arbitrarily defined as “yaw” around a manipulator assembly yaw axis  223 C. As shown, the rotational axis of yaw joint  211 C is aligned with a remote center of motion  246 C, 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  206 C is rotatable in a horizontal or x, y plane and yaw joint  211 C is configured to allow first manipulator link  213 C in entry guide manipulator  230 C to rotate about yaw axis  223 C. Setup link  206 C, yaw joint  211 C, and first manipulator link  213 C provide a constantly vertical yaw axis  223  for entry guide manipulator  230 C, as illustrated by the vertical line through yaw joint  211 C to remote center of motion  246 C. 
     A distal end of first manipulator link  213 C is coupled to a proximal end of a second manipulator link  215 C by a first actively controlled rotational joint  214 C. A distal end of second manipulator link  215 C is coupled to a proximal end of a third manipulator link  217 C by a second actively controlled rotational joint  216 C. A distal end of third manipulator link  217 C is coupled to a distal portion of a fourth manipulator link  219 C by a third actively controlled rotational joint  218 C. 
     In one embodiment, links  215 C,  217 C, and  219 C 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  214 C is actively rotated, then joints  216 C and  218 C are also actively rotated so that link  219 C moves with a constant relationship to link  215 C. Therefore, it can be seen that the rotational axes of joints  214 C,  216 C, and  218 C are parallel. When these axes are perpendicular to rotational axis  223  of joint  211 C, links  215 C,  217 C, and  219 C move with reference to link  213 C 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. 2C  at remote center of motion  246 C in this aspect. The motion around the manipulator assembly pitch axis is represented by arrow  221 C. Since links  215 C,  217 C, and  219 C move as a single assembly in this embodiment, first manipulator link  213 C may be considered an active proximal manipulator link, and second through fourth manipulator links  215 C,  217 C, and  219 C may be considered collectively an active distal manipulator link. 
     An entry guide manipulator assembly platform  232 C, sometimes referred to as platform  232 C, is coupled to a distal end of fourth manipulator link  219 C. An entry guide manipulator assembly  233 C is rotatably mounted on platform  232 C. Entry guide manipulator assembly  233 C includes instrument manipulator positioning system  231 C. 
     Each of plurality of surgical device assemblies  280 C is coupled to entry guide manipulator assembly  233 C by an insertion assembly  235 C. Entry guide manipulator assembly  233 C rotates plurality of surgical device assemblies  280 C as a group around axis  225 C. Specifically, entry guide manipulator assembly  233 C rotates as a single unit with reference to platform  232 C in a motion that may be arbitrarily defined as “roll” around an entry guide manipulator assembly roll axis  225 C. 
     For minimally invasive surgery, the instruments must remain substantially stationary with respect to the location at which the instruments enter the patient&#39;s body, either at an incision or at a natural orifice, to avoid unnecessary tissue damage. Accordingly, the yaw and pitch motions of the instruments should be centered around a single location on manipulator assembly roll axis  225 C that stays relatively stationary in space. This location is referred to as remote center of motion  246 C. 
     For single port surgery, in which all the instruments (including a camera instrument) must enter via a single small incision (e.g., at the umbilicus) or natural orifice, all instruments must move with reference to such a generally stationary remote center of motion  246 C. Therefore, remote center of motion  246 C of entry guide manipulator  230 C is defined by the intersection of manipulator assembly yaw axis  223 C and manipulator assembly pitch axis  221 C. The configuration of links  215 C,  217 C, and  219 C, and the configuration of joints  214 C,  216 C, and  218 C are such that remote center of motion  246 C is located distal of entry guide manipulator assembly  233 C with sufficient distance to allow entry guide manipulator assembly  233 C to move freely with respect to the patient. Manipulator assembly roll axis  225 C also intersects remote center of motion  246 C. 
     Cannula  275 C is removably coupled to a cannula mount, which in one embodiment is coupled to the distal end  219 C_P of fourth manipulator link  219 C. In one implementation, the cannula mount is coupled to link  219 C by a rotational joint that allows the mount to move between a stowed position adjacent link  219 C and an operational position that holds the cannula in the correct position so that remote center of motion  246 C is located along the cannula. During operation, the cannula mount is fixed in position relative to link  219 C according to one aspect. 
     In this description, a cannula is typically used to prevent an instrument or an entry guide from rubbing on patient tissue. Cannulas may be used for both incisions and natural orifices. For situations in which an instrument or an entry guide does not frequently translate or rotate relative to its insertion (longitudinal) axis, a cannula may not be used. For situations that require insufflation, the cannula may include a seal to prevent excess insufflation gas leakage past the instrument or entry guide. Examples of cannula assemblies which support insufflation and procedures requiring insufflation gas at the surgical site may be found in U.S. patent application Ser. No. 12/705,439 (filed Feb. 12, 2010; disclosing “Entry Guide for Multiple Instruments in a Single Port System”), the full disclosure of which is incorporated by reference herein for all purposes. For thoracic surgery that does not require insufflation, the cannula seal may be omitted, and if instruments or entry guide insertion axis movement is minimal, then the cannula itself may be omitted. A rigid entry guide may function as a cannula in some configurations for instruments that are inserted relative to the entry guide. Cannulas and entry guides may be, e.g., steel or extruded plastic. Plastic, which is less expensive than steel, may be suitable for one-time use. 
     The various passive setup joints/links and active joints/links allow positioning of the instrument manipulators to move the instruments and imaging system with a large range of motion when a patient is placed in various positions on a movable table. In some embodiments, a cannula mount may be coupled to the proximal link or first manipulator link  213 C. 
     Certain setup and active joints and links in the manipulator arm may be omitted to reduce the surgical system&#39;s size and shape, or joints and links may be added to increase degrees of freedom. It should be understood that the manipulator arm may include various combinations of links, passive joints, and active joints (redundant DOFs may be provided) to achieve a necessary range of poses for surgery. Furthermore, various instruments alone or surgical device assemblies including entry guides, multiple instruments, and/or multiple entry guides, and instruments coupled to instrument manipulators (e.g., actuator assemblies) via various configurations (e.g., on a proximal face or a distal face of the instrument transmission means or the instrument manipulator), are applicable in aspects of the present disclosure. 
     Each of plurality of surgical device assemblies  280 C includes an instrument manipulator assembly and one of a surgical instrument and a camera assembly. In  FIG. 2C , two of a plurality of surgical device assemblies  280 C are visible, and each of the two visible surgical device assemblies includes an instrument manipulator assembly and an instrument. Each of instrument manipulator assemblies  240 C 1  and  240 C 2  is teleoperated, in one aspect, and so each is sometimes referred to as a teleoperated instrument manipulator assembly. Each of instrument manipulator assemblies  240 C 1 ,  240 C 2  is coupled to entry guide manipulator assembly  233 C by an different insertion assembly, e.g. instrument manipulator assembly  240 C 1  is coupled to entry guide manipulator assembly by insertion assembly  235 C. 
     In one aspect, insertion assembly  235 C is a telescoping assembly that moves the corresponding surgical device assembly away from and towards entry guide manipulator assembly  235 C. In  FIG. 2C , insertion assembly  235 C is in the fully retracted position. 
     Each instrument manipulator assembly  240 C 1 ,  240 C 2  includes a plurality of motors that drive a plurality of outputs in an output interface of instrument manipulator assembly  240 C 1 ,  240 C 1 . Each of instruments  260 C 1 ,  260 C 2  includes a body that houses a transmission unit. The transmission unit includes an input interface including a plurality of inputs. Each of instruments  260 C 1 ,  260 C 2  also includes a shaft  262 C 1 ,  262 C 2  sometimes referred to as a main tube that extends in the distal direction from the body. An end effector  263 C is coupled to a distal end of the shaft. See U.S. Patent Application No. 61/866,115 (filed on 15 Aug. 2013), which is incorporated by reference, for one example of an instrument manipulator assembly and a surgical instrument. 
     Each of instruments  260 C 1 ,  260 C 2  is coupled to the instrument mount interface of a corresponding instrument manipulator assembly  240 C 1 ,  240 C 2  so that a plurality of inputs in an input interface of the transmission unit in instrument  260 C 1 ,  260 C 2  are driven by plurality of outputs in the instrument mount interface of instrument manipulator assembly  240 C 1 ,  240 C 2 . See U.S. Patent Application No. 61/866,115 (filed on 15 Aug. 2013). 
     In one aspect, a membrane interface that is part of a sterile surgical drape may be placed between the instrument mount interface of instrument manipulator assembly  240 C and the input interface of the transmission unit in instrument  260 C. See, for example, U.S. Patent Application Publication No. 2011/0277776 A1 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 instrument manipulator assembly  240 C and the input interface of the transmission unit in instrument  260 C. See, for example, U.S. Patent Application Publication No. 2011/0277775 A1 for an example of a sterile adapter and a sterile surgical drape. 
     In one aspect, one or more instrument manipulator assemblies may be configured to support and actuate a particular type of instrument, such as a camera instrument. As shown in  FIG. 2C , the shafts of plurality of surgical device assemblies  280 C extend distally from a body of the instruments. The shafts extend through a common cannula  275 C placed at the entry port into the patient (e.g., through the body wall or at a natural orifice). In one aspect, an entry guide  270 C is positioned within cannula  275 C, and each instrument shaft extends through a channel in entry guide  270 C, so as to provide additional support for the instrument shafts. 
     The surgeries that can be performed using surgical system  200 C may be performed on different regions of the body. For example, one surgery may be performed through the mouth of a patient. Another surgery may be performed between the ribs of the patient. Other surgeries may be performed through other orifices of the patient or through an incision in the patient. Each different entry into a patient may require a different shape and/or different size of an entry guide. Thus, an appropriate guide  270 C is selected for a particular surgery. 
     An entry guide, which is suitable for abdominal surgery, may not be suitable for surgery through the mouth or between the ribs. The size and shape of an entry guide limits the locations of channels through the entry guide for shafts  262 C 1 ,  262 C 2  of plurality of surgical device assemblies  280 C. Thus, instrument manipulator positioning system  231 C moves each of instrument manipulator assemblies  240 C 1 ,  240 C 2  and corresponding instrument  260 C 1 ,  260 C 2  so that each of shafts  262 C 1 ,  262 C 2  is properly aligned for entry into a different channel of entry guide  270 C. In one aspect, instrument manipulator positioning system  231 C moves each of instrument manipulator assemblies  240 C 1 ,  240 C 2  and corresponding instrument  260 C 1 ,  260 C 2  to align shaft  262 C 1 ,  262 C 2  so that any bend in shaft  262 C 1 ,  262 C 2  between a proximal end of the shaft and a point of contact of the shaft with entry guide  270 C as the shaft passes through entry guide  270 C does not damage the instrument and does not inhibit operation of the instrument. Thus, not only is system  200 C configured to use a variety of instruments, but also system  200 C is configured to use a variety of different entry guides. Various combinations of these different entry guides are provided in kits. 
       FIG. 2D  is an illustration of example paths  226  to  229  along which a different one of plurality of surgical device assemblies  280 C can be moved by instrument manipulator positioning system  231 C. In this example, three of the paths  227  to  229  are curved paths and one of the paths  226  is a linear path. In one aspect, linear path  226  is used for a camera instrument and the three curved paths  227  to  229  are used for surgical instruments. Each entry guide that can be used with system  200 C has a channel positioned so that a surgical device assembly positioned on one of the four paths can pass the shaft of that surgical device assembly through that channel and work correctly for that instrument&#39;s intended purpose. In one aspect, instrument manipulator positioning system  231 C automatically moves each of the entire surgical device assemblies to the appropriate location on the path for the entry guide being used in system  200 C. In another aspect, each of the entire surgical device assemblies is manually moved to the appropriate location on the path for the entry guide being used in system  200 C. 
       FIG. 2E  is an illustration of one implementation  210 E of patient side support system  210 C. In this aspect, patient side support system  210 E is implemented as a patient-side cart  210 E having a passive setup arm  220 E and entry guide manipulator  230 E. Entry guide manipulator  230 E supports a plurality of surgical device assemblies. 
     In one aspect, at least one of the plurality of surgical device assemblies includes an instrument manipulator assembly  240 E, a sterile adapter assembly  250 E, and an instrument  260 E. A main tube, sometimes referred to as a shaft, of instrument  260 E extends through a channel in entry guide  270 E during a surgical procedure. 
     The use of instrument manipulator assembly  240 E and sterile adapter assembly  250 E to couple instrument  260 E to entry guide manipulator  230 E is illustrative only and is not intended to be limiting. Instrument  260 E can be coupled to entry guide manipulator in other ways so that instrument manipulator positioning system  231 E can align shaft  262 E with the corresponding channel in entry guide  270 E for entry of shaft  262 E into that channel. 
     Entry guide  270 E is movably mounted in cannula  275 E. Entry guide  270 E may maintain an insufflation seal, if necessary, and entry guide  270 E supports the shafts of the instruments at the entry into the body of patient  299 . As explained more completely below, a plurality of different entry guides can be mounted and used in patient side support system  210 E. Typically, a different entry guide is used for each different type of surgery. 
     The different surgeries that can be performed using patient side support system  210 E may be performed on different regions of the body. For example, one surgery may be performed through the mouth of patient  299 . Another surgery may be performed between the ribs of patient  299 . Other surgeries may be performed through other orifices of patient  299 . Entry guide  270 E, which is suitable for abdominal surgery, may not be suitable for surgery through the mouth or between the ribs. A different shaped entry guide may be required for surgery through the mouth or between the ribs. 
     Not only is patient side support system  210 E configured to use a variety of instruments, but also system  210 E is configured to use a variety of different entry guides. Various combinations of these different entry guides are provided in kits. 
     When a rib entry guide for a surgery between the ribs is substituted for entry guide  270 E, the channel configuration of the rib entry guide is different from the channel configuration of entry guide  270 E, e.g., the layout of the channels relative to each other is different in the two entry guides. Also, one or more different surgical device assemblies may be mounted on entry guide manipulator  230 E after the surgery using entry guide  270 E is completed and the rib entry guide is mounted in patient side system  201 E. Thus, the positions of the shafts of the surgical device assemblies are unlikely to be properly aligned for insertion into the rib entry guide. To correct this problem, entry guide manipulator  230 E includes an instrument manipulator positioning system  231 E. Instrument manipulator positioning system  231 E simultaneously positions instrument mount interfaces for the surgical device assemblies with respect to the channels in the rib entry guide so that when a surgical device assembly is mounted on each of the instrument mount interfaces each instrument shaft is not damaged as the shaft passes through the corresponding channel in rib entry guide. This is done with little or no user input in some aspects. 
     Returning to the configuration illustrated in  FIG. 2E , the plurality of surgical device assemblies mounted on entry guide manipulator  230 E is spaced closely together. To permit this close packing arrangement and to permit the channels in entry guide  270 E to be close together, in one aspect, the shafts of the instruments are angled from the instrument housings (See  FIG. 4B ) and in some aspects bent against entry guide  270 E as the shafts pass through cannula  275 E. As just described, instrument manipulator positioning system  231 E simultaneously positions each of the entire surgical device assemblies, as needed, with respect to a corresponding channel in entry guide  270 E so that each instrument shaft is not damaged as the shaft passes through the corresponding channel in entry guide  270 E. Again, this is done with little or no user input, in one aspect. 
     In one aspect, instrument manipulator positioning system  231 E limits the number of actuators and sensors required. Instrument manipulator positioning system  231 E is synchronized with a roll system in entry guide manipulator  230 E. The roll system rolls the surgical device assemblies as a group. In one aspect, gearing is used in instrument manipulator positioning system  231 E to align the shafts of the surgical device assemblies for insertion into entry guide  270 E and to maintain the synchronization. 
     To further simplify the design and the size of instrument manipulator positioning system  231 E, in one aspect, the motion of instrument manipulator positioning system  231 E used to align each of the plurality of instrument shafts with respect to the corresponding channels in entry guide  270 E is limited to one degree of freedom in one aspect, and is limited to two degrees of freedom in another aspect. Irrespective of the number of degrees of freedom, the motion is in a plane. In addition, the range of motion of each of the plurality of surgical device assemblies is limited to the extent possible so that the range of motion of the plurality of surgical device assemblies does not compete for space that might otherwise be used for drape management, electronics, and reducing the overall size of system  210 E. 
     Hence, as explained more completely below, entry guide manipulator  230 E positions each entire surgical device assembly so that the shaft of the surgical device assembly is aligned for entry in the corresponding channel of entry guide  270 E for that particular surgical device assembly. If the shaft is bent upon passing through entry guide  270 E, the shaft is aligned so that any bending does not damage the instrument and does not inhibit operation of the instrument. This simultaneous automatic alignment of the instrument shafts is done for each entry guide that is used in system  210 E. 
     In one aspect, a control system automatically checks on the compatibility of the surgical device assemblies mounted on entry guide manipulator  230 E with the channel locations in entry guide  270 E. In some instances, it is necessary to flex, e.g., slightly bend, the shaft of the instrument to insert the shaft in the appropriate channel in entry guide  270 E. If this flex will damage the instrument, an alarm is issued by the control system when the instrument is mounted in system  210 E and the system rejects use of that instrument. When a shaft of an instrument is flexed so that the resulting stresses are outside an allowable stress profile, the shaft may be damaged, e.g., permanently bent, and consequently the tendons that run through the shaft may not operate properly. 
     If the instrument is compatible with the entry guide, the control system checks other elements of the surgical system for compatibility with the entry guide, e.g., drapes, cameras, foot pedal control assemblies, master control assemblies, etc. Finally, the control system makes any needed adjustments in the user interface elements, allowable control modes, type and behavior of control modes, etc. for both the surgeon and patient side assistant based on the entry guide configuration. For example, if the entry guide is used in ear, throat, and nose surgery, the configuration and allowable range of motion of the various instruments would be different from entry guide  270 E that is used for abdominal surgery, and so the control system automatically makes the necessary changes based on the entry guide to be used in the procedure. 
     As explained more completely below, in one aspect, each instrument  260 E is positioned by entry guide manipulator  230 E to maintain the bending stress or stresses on the instrument shaft within a predetermined stress profile. This assures that the bending does not damage the instrument and that the bending does not affect the correct operation of the instrument. For each entry guide with a different channel configuration, entry guide manipulator  230 E positions each instrument so that the bending stress or stresses on the instrument shaft remains within the predetermined stress profile. 
     In  FIG. 2E , elements  202 E,  203 E,  204 E,  205 E,  206 E, and  211 E of passive setup arm  220 E are equivalent to elements  202 C,  203 C,  204 C,  205 C,  206 C, and  211 C of passive setup arm  220 C. Thus, the description of passive setup arm  220 C is applicable to passive setup  220 E, and so is not repeated here. Elements  213 E,  214 E,  215 E,  216 E,  217 E,  218 E and  219 E of entry guide manipulator  230 E are equivalent to elements  213 C,  214 C,  215 C,  216 C,  217 C,  218 C and  219 C of entry guide manipulator  230 C. Thus, the description of elements  213 C,  214 C,  215 C,  216 C,  217 C,  218 C and  219 C of entry guide manipulator  230 C is applicable to elements  213 E,  214 E,  215 E,  216 E,  217 E,  218 E and  219 E of entry guide manipulator  230 E, and so is not repeated here. Similarly, base  201 E is equivalent to base  201 C. 
     Entry guide manipulator  230 E changes the pitch around axis  221 E of the plurality of surgical device assemblies as a group. Entry guide manipulator  230 E changes the yaw around axis  223 E of the plurality of surgical device assemblies as a group. In one aspect, entry guide manipulator  230 E also rolls the plurality of surgical device assemblies as a group about a roll axis  225 E. Roll axis  225 E, in this aspect, is coincident with a longitudinal axis of cannula  275 E. Pitch axis  221 E, yaw axis  223 E, and roll axis  225 E intersect at remote center of motion  246 E. Remote center of motion  246 E is located along cannula  275 E. 
     While it not shown in  FIG. 2E , the surgical system also includes a control system and a master control console equivalent to those described with respect to  FIG. 2C . In  FIG. 2E , the surgery is in the abdomen of patient  299 . However, the surgical system including patient side support system  210 E is used for a wide variety of surgeries. The variety of surgical procedures uses various combinations of instruments. 
     For convenience, the instruments, in one aspect, are grouped into sets of instruments based on the shaft characteristics of the instruments, e.g., standard surgical instrument, advanced surgical instruments, and camera instruments, as explained more completely below. Briefly, the shafts of the advanced surgical instruments have a larger diameter than the diameter of the standard surgical instruments. The grouping of the instruments is for ease of discussion and the names of the groups are not intended to limit the instruments to any specific surgical instruments. In some surgeries, a manual instrument or instruments may be used in conjunction with teleoperated surgical instruments. A manual instrument is an instrument that a person controls using a handle or grip of the instrument itself. 
     The shaft of a camera instrument has a fixed bend. In one aspect, two different camera instruments are provided. One of the camera instruments has the fixed bend at a first location in a shaft of the camera instrument and the other of the camera instruments has the fixed bend in at a second location in a shaft of that camera instrument. The first and second locations are different locations. 
       FIGS. 3A and 3B  are illustrations of a plurality of surgical device assemblies  300  mounted on entry guide manipulator  230 E. As noted above, each of the plurality of surgical device assemblies  300  includes an instrument manipulator assembly  240 _ 1 , a sterile adapter assembly  250 _ 1 , and an instrument  260 _ 1 . In  FIG. 3A , each of the plurality of surgical device assemblies  300  is positioned at an initial position on an insertion assembly  331 . Insertion assembly  331  is an example of a longitudinal motion mechanism. In  FIG. 3B , three of the four surgical device assemblies have been moved distally on the insertion assembly. Arrow  390  defines the distal and proximal directions. Here, the distal direction is towards patient  299 . The proximal direction is away from patient  299 . 
     The proximal end of each insertion assembly in  FIGS. 3A and 3B  is shown as floating. As explained more completely below, in one aspect, the proximal end of each insertion assembly is mounted on a movable platform. The movable platform is coupled to instrument manipulator positioning system  231 E in entry guide manipulator  230 E. The movable platform allows the lateral motion mechanism of entry guide manipulator  230 E to move the movable platform in a plane perpendicular to the longitudinal axis of entry guide  270 , and consequently the entire surgical device assembly, so that the shaft of the instrument attached to the movable platform can be inserted in the corresponding channel of entry guide  270  without damaging the shaft, e.g., without exceeding the limits on the bending stresses. Once the instrument is properly positioned by instrument manipulator positioning system  231 E, the movable platform is locked in place. 
       FIGS. 3A and 3B  illustrate the configuration that is used as an example in the following description. Instrument  260 _ 0  is a camera instrument. Instruments  260 _ 1  to  260 _ 3  are standard or advanced surgical instruments. Instrument  260 _ 1  is referred to as a first surgical instrument, instrument  260 _ 2  as a second surgical instrument, and instrument  260 _ 3  as a third surgical instrument. Thus, the camera instrument is mounted roughly at the twelve o&#39;clock position on a clock; the first surgical instrument is mounted roughly at the three o&#39;clock position, and so on. The first, second, and third surgical instruments may be instruments of the same type, or instruments of different types. The types of the surgical instruments are selected for compatibility with the channel sizes in the entry guide, as explained more completely below. 
     As illustrated in  FIG. 3B , each insertion assembly includes three components. Using insertion assembly  331 _ 1  as an example, insertion assembly  331 _ 1  includes a frame  331 A_ 1 , a mid-carriage  331 B_ 1 , and a distal carriage  331 C_ 1 . Mid-carriage  331 B_ 1  rides on a ball screw in frame  331 A_ 1 . In one aspect, the ball screw has a 6 mm pitch, and so the ball screw is back-drivable. Mid-carriage  331 B_ 1  includes metal belts that drive distal carriage  331 C_ 1 . Distal carriage  331 C_ 1  is attached to surgical device assembly  300  that includes surgical instrument  260 _ 1 . 
     Thus, as described more completely below, when a positioning element in instrument manipulator positioning system  231 E moves the movable platform affixed to the proximal end of frame  331 A_ 1 , insertion assembly  331 _ 1  and the surgical device assembly of plurality of surgical device assemblies  300  including surgical instrument  260 _ 1  and its shaft are all moved as a single unit. Thus, the movement of the positioning element in instrument manipulator positioning system  231 E moves insertion assembly  331 _ 1  and entire surgical device assembly  300  including surgical instrument  260 _ 1  and its shaft along the same trajectory that the positioning element follows. 
     Prior to considering the positioning of the instrument in plurality of surgical device assemblies  300  in further detail, one aspect of a surgical device assembly is described.  FIGS. 4A and 4B  are a more detailed illustration of one aspect of a surgical device assembly in plurality of surgical device assemblies  300 . 
     A base assembly  432  ( FIG. 4A ) is connected to a rotatable base in entry guide manipulator  230 E. Insertion assembly  331  is connected to a floating platform (not visible) in base assembly  432 . There is an opening  433  in the distal end of base assembly  432  in which insertion assembly  331  can move about, as described more completely below. 
     In this example, the housing of base assembly  432  is roughly wedge shaped (pie-shaped) to allow assembly  432  to be closely positioned to similar housings as illustrated in  FIG. 2E . A vertex of the wedge shape of each of the base assemblies of the four surgical device assemblies is arranged around an extended longitudinal axis of cannula  275 E. 
     An instrument manipulator assembly  240  is affixed to insertion assembly  331 . Instrument manipulator assembly  240  is an example of the instrument manipulator assemblies illustrated in  FIGS. 2A to 2C, 2E, 3A, and 3B . Instrument manipulator assembly  240  includes a plurality of drive units. 
     A sterile adapter assembly  250  is mounted on instrument manipulator assembly  240 . Sterile adapter assembly  250  is an example of the sterile adapter assemblies illustrated in  FIGS. 2E, 3A, and 3B . Sterile adapter assembly  250  includes a plurality of intermediate disks. Each intermediate disk is coupled to a drive disk on a drive unit of instrument manipulator assembly  240 . Hence, in this example, the instrument mount interface is provided by a combination of instrument manipulator assembly  240  and sterile adapter assembly  250 . However, the instrument mount interface could alternatively be defined as a distal face of sterile adapter assembly  250  mounted on instrument manipulator assembly  240 . 
     Sterile adapter assembly  250  includes a sterile drape (not shown). Sterile drapes are known and so are not described in further detail. See for example, U.S. Pat. No. 7,666,191 B2, U.S. Pat. No. 7,699,855 B2, U.S. Patent Application Publication No. 2011/0277775 A1, and U.S. Patent Application Publication No. 2011/0277776 A1, all of which are incorporated herein by reference. The sterile drape drapes at least a portion of system  210 E to maintain a sterile field during a surgical procedure while sterile adapter assembly  250 E also facilitates efficient and simple instrument exchange. 
       FIG. 4B  is a more detailed illustration of an example of a surgical instrument  260 . Surgical instrument  260  is an example of the surgical instruments illustrated in  FIGS. 2A, 2C, 2E, 3A, and 3B . Surgical instrument  260 , in this aspect, includes a driven interface assembly  461 , a transmission unit  465 , a main tube  467 , a parallel motion mechanism  468 , a wrist  469 , and an end effector  470 . Wrist  469  is described, for example, in U.S. Patent Application Publication No. 2003/0036478 A1 (disclosing “Surgical Tool Having Positively Positionable Tendon-Activated Multi-Disk Wrist Joint”), which is incorporated herein by reference. Parallel motion mechanism  868  is described, for example, in U.S. Pat. No. 7,942,868 B2 (disclosing “Surgical Instrument With Parallel Motion Mechanism”), which also is incorporated herein by reference. 
     Driven interface assembly  461  includes a plurality of driven disks. Each driven disk is coupled to a corresponding intermediate disk in sterile adapter assembly  250  when surgical instrument  260  is mounted in sterile adapter  250 , as illustrated in  FIGS. 2D, 3A, and 3B . 
     Mechanical components (e.g., gears, levers, gimbals, cables etc.) in transmission unit  465  transfer forces from the driven disks to cables, wires, and/or cable, wire, and hypotube combinations that run through main tube  467  to control movement of parallel motion mechanism  468 , wrist  469 , and end effector  470 . Main tube  467  has a bearing  471  at the proximal end of main tube  467 . 
     Main tube  467  is substantially rigid, which means that main tube  467  can be bent slightly between transmission unit  465  and entry guide  270 E. This bending allows the channels in entry guide  270 E to be spaced closer together than the size of the base assemblies would otherwise allow. The bending is resilient so that main tube  467  assumes its straight shape when surgical instrument  260 E is withdrawn from entry guide  270 E (the main tube may be formed with a permanent bend as in the camera instrument). The allowable stress profile, mentioned above, is a stress profile such that the bending remains resilient and main tube  467  is not permanently deformed by the bending stresses. 
     Instrument manipulator assembly  240  ( FIG. 4A ) includes a radio-frequency identification (RFID) reader  445  in a distal end of instrument manipulator assembly  240 . Surgical instrument  260  has an RFID tag  455  mounted on a proximal end surface of instrument  260 . When surgical instrument  260  is mounted in sterile adapter assembly  250 , RFID tag  455  is positioned under RFID reader  445 . After surgical instrument  260  is mounted in sterile adapter assembly  250 , the control system receives the information from RFID reader  445  and uses the information in identifying surgical instrument  260  to determine the compatibility of surgical instrument  260  with entry guide  270 E. 
       FIG. 5A  is a schematic representation of four base assemblies  432 _ 0 ,  432 _ 1 ,  432 _ 2 , and  432 _ 3  mounted on entry guide manipulator  230 E.  FIG. 5A  shows that four wedge-shaped assemblies  432 _ 0 ,  432 _ 1 ,  432 _ 2 , and  432 _ 3  form a circle  501 . Center  501 C of circle  501  is on the extended longitudinal axis of cannula  275 E. 
     The use of wedge-shaped base assemblies is illustrative only and is not intended to be limiting. The base assemblies could have a square shape, a rectangular shape, or other shape so long as the base assemblies can be mounted on entry guide manipulator  230 E and then moved as a group in roll, pitch, and yaw by entry guide manipulator  230 E. For example, in  FIG. 5F , base assemblies having a hexagonal shape as shown in a configuration  590  that could be mounted on and moved by entry guide manipulator  230 E. 
       FIG. 5B  is a cross sectional view of a first entry guide  570 S that is referred to as a standard entry guide  570 S. Entry guide  570 S is movably, e.g., rotatably, mounted in a cannula  580 . Entry guide  570 S has four lumens that are referred to as channels. The channels extend from a proximal end of entry guide  570 S to a distal end of entry guide  570 S, e.g., the channels extend from a first end to a second end of the entry guide. This is true for each of the channels of an entry guide described herein. In one aspect, entry guide  570 S is entry guide  270 E and cannula  580  is cannula  275 E. 
     In this aspect, one of the surgical device assemblies includes an endoscope and a camera. This instrument is referred to as a camera instrument. The camera instrument has a pre-bent shaft. The bend in the shaft remains between the distal part of transmission unit  465  and the proximal end of entry guide  270 E, e.g., the bend does not enter entry guide  270 E. The cross-section of the portion of the camera shaft that goes through entry guide  270 E and cannula  275 E is an oblong shape, in one aspect. Alternatively, the cross-section of the portion of the camera shaft that goes through entry guide  270 E and cannula  275 E could have a circular shape. 
     Thus, standard entry guide has a camera channel  571 S with an oblong cross section, and three surgical instrument channels  572 S 1 ,  572 S 2 ,  572 S 3  that are circular in cross section. In this aspect, each of the three surgical instrument channels  572 S 1 ,  572 S 2 ,  572 S 3  is the same size, e.g., has the same diameter. The diameter is selected such that a sheathed shaft of a surgical instrument can be passed through the channel. Surgical instrument channels  572 S 1 ,  572 S 2 ,  572 S 3  are referred to as standard surgical instrument channels. 
     In  FIG. 5A , a channel in standard entry guide  570 S that is associated with a particular base assembly  432 _ 0 ,  432 _ 1 ,  432 _ 2 , and  432 _ 3  is shown as a dotted line. A channel being associated with a base assembly means that the shaft of the surgical instrument mounted on that base assembly is inserted through the channel. For example, surgical instrument  260 _ 2  is mounted on base assembly  432 _ 2  and shaft  467  passes through channel  572 S 2 . Thus, both base assembly  432 _ 2  and surgical instrument  260 _ 2  are associated with channel  572 S 2 . 
       FIG. 5C  is a cross sectional view of a second entry guide  570 MS. Entry guide  570 MS is positioned in a cannula  581 . Entry guide  570 MS also has four lumens that are referred to as channels. Entry guide  570 MS has an outer diameter that is larger than the outer diameter of standard entry guide  570 S. 
     Entry guide  570 MS has an oblong camera channel  571 MS, and two standard circular surgical instrument channels  572 MS 1  and  572 MS 3 . In this aspect, entry guide  570 MS also includes a manual instrument channel  573 MS. In one aspect, a manually controlled surgical instrument is passed through channel  573 MS. In another aspect, a teleoperated surgical instrument is passed through channel  573 MS. 
     In  FIG. 5D , an x-axis  590  and a y-axis  591  have an origin at a center of entry guide  570 MS. Entry guide  570 S, which is represented by dashed lines, is overlaid on entry guide  570 MS with its center also at the origin. The center of entry guide  570 MS in  FIG. 5D  represents a longitudinal axis of entry guide  570 MS. 
     Assuming that entry guide  570 MS is being used and the positioning elements for the surgical instruments attached to base assemblies  432 _ 1  and  432 _ 3  are in the standard positions as shown in  FIG. 5A , the shafts of surgical instruments  260 _ 1  and  260 _ 3  ( FIG. 3A ) are not properly positioned for insertion through channels  572 MS 1  and  572 MS 3 . Instead, the shafts of surgical instruments  260 _ 1  and  260 _ 3  are positioned to pass though channels  57251  and  572 S 3  in standard entry guide  570 S. Similarly, camera instrument  260 _ 0  is positioned for channel  571 S and not channel  571 MS. 
     In one aspect, instrument manipulator positioning system  231 E in entry guide manipulator  230 E moves a first positioning element that is associated with surgical instrument  260 _ 1  to a position indicated by arrow  581 . Specifically, the movement of the positioning element is coupled to surgical instrument  260 _ 1 , and so moves the shaft of surgical instrument  260 _ 1  to the appropriate position to enable insertion of the shaft into channel  572 MS 1  without damaging the shaft. 
     Similarly, instrument manipulator positioning system  231 E in entry guide manipulator  230 E moves a second positioning element that is associated with surgical instrument  260 _ 3  to a position indicated by arrow  583 . The instrument manipulator positioning system in entry guide manipulator  230 E also moves a third positioning element that is associated with camera instrument  260 _ 0  to a position indicated by arrow  580 . In the new positions, the shafts of the surgical instruments and the shaft of the camera instrument are positioned to enable insertion through the corresponding channels in entry guide  570 MS. In one aspect, all of the positioning elements are simultaneously moved to the correct location. In one aspect, the positioning elements are included in the lateral motion mechanism of system  231 E. 
     In  FIG. 5E , the dotted lines represent a position of insertion assembly  531  and a surgical device assembly  500  with a shaft  567  configured for a first entry guide, e.g., entry guide  570 S. If shaft  567  is withdrawn from entry guide  570 S and a second entry guide such as entry guide  570 MS is placed in the system, the position of shaft  567  as shown by the dotted line is not correct for entry into the corresponding channel in the second entry guide (See  FIG. 5D ). 
     The solids lines in  FIG. 5E  illustrate the result of instrument manipulator positioning system  550  in entry guide manipulator  530  moving positioning element  549  that is coupled to surgical device assembly  500 . In particular, insertion assembly  531  is mounted on a floating platform  532 A that is connected to positioning element  549 . As positioning element  549  is moved by instrument manipulator positioning system  550 , floating platform  532 A is moved, which in turn moves entire surgical device assembly  500  including shaft  567 . 
     Thus, to reposition surgical device assembly  500  for entry guide  570 MS, instrument manipulator positioning system  550  moves positioning element  549  that in turn moves floating platform  532 A so that insertion assembly  531  and entire surgical device assembly  500  including shaft  567  are moved from the position represented by the dotted lines to the position shown in  FIG. 5E  by the solid lines. In one aspect, positioning element  549  is moved by manually turning a knob. In another aspect, positioning element  549  is moved using a servomotor. 
     Only one surgical device assembly  500  and its associated base assembly  532  are shown in  FIG. 5E . However, this is representative of each of the four base assemblies in one aspect, and so the description is applicable to each of the total number of base assemblies, e.g., four base assemblies, or in some aspects is applicable to a number of base assemblies smaller than the total number of base assemblies. Also, the use of an insertion assembly to couple the surgical device assembly to the associated base assembly is illustrative only, and is not intended to be limiting. In another aspect, the surgical device assembly is coupled directly to the base assembly. 
       FIG. 5E  also illustrates circular bending of shaft  567 . In circular bending, the bend in shaft  567  is an arc of a circle. When shaft  567  is circularly bent, the circular bend introduces the minimum stress over the length of the bend of all of the possible bends, as discussed more completely below. 
       FIG. 6A  is an illustration of one implementation of an instrument manipulator positioning system  640 A in entry guide manipulator  530 . Only one surgical device assembly  500  and its associated base assembly  532  are shown in  FIG. 6A . However, this is representative of each of the total number of base assemblies in one aspect, and so the description is applicable to each of four base assemblies, or in some aspects is applicable to a number of base assemblies smaller than the total number of base assemblies. 
     Floating platform  600 A, e.g., a moveable platform, in base assembly  532  is connected to insertion assembly  531 . Thus, as indicated above, movement of floating platform  600 A moves the location of shaft  567 . A positioning element  610  in lateral motion mechanism of instrument manipulator positioning system  640 A is coupled to floating platform  600 A. In this example, positioning element  610  and floating platform  600 A can be moved in four degrees of freedom, e.g., along a first axis  601 , along a second axis  602 , in pitch  603 , and in yaw  604 . First axis  601  and second axis  602  are in a plane that is perpendicular to a longitudinal axis of the entry guide, as previously shown. 
     In one aspect, platform  600 A is suspended on a rail system so that positioning element  610  can move floating platform  600 A and hence insertion assembly  531  in directions  601 ,  602 . Platform  600 A also is movably suspended on a support  620  that allows changing the pitch of positioning element  610  and platform  600 A, e.g., the rail system is mounted on support  620 . Support  620  can also rotate about anchor  630  to change the yaw of positioning element  610  and platform  600 A. 
     As indicated above, patient side support system  210 E is used with a wide variety of entry guides. The particular entry guide used typically depends on the surgery being performed. In some instances, a channel in an entry guide may not extend straight through the entry guide. In this case, the instrument shafts exiting the entry guide are not all parallel to the longitudinal axis of the entry guide, but rather the instrument shafts are splayed. The entry guide has one or more channels that are at an angle to the longitudinal axis of the entry guide, e.g., the channel is canted. For this entry guide, pitch and/or yaw of positioning element  610  can be changed to insert shaft  567  into the chanted channel. 
       FIG. 6B  is a cross-sectional view of an entry guide  670  with at least one canted channel  670 C, e.g., channel  670 C is at an angle to longitudinal axis  690 . Longitudinal axis  690  extends from distal end  670 D of entry guide  670  to the proximal end  670 P of entry guide  670 . Lengthwise axis  670 CL of channel  670 C is angled relative to longitudinal axis  690 . Entry guide  670  may have more than the two channels visible in  FIG. 6B . 
     In one aspect, channel  670 C is a manual channel. The angle of the manual channel is selected to facilitate aiming a manual instrument, e.g., a stapler, at the center of the surgical site. 
       FIG. 6C  illustrates an example of an instrument manipulator positioning system  640 C that moves insertion assembly  531  and consequently shaft  567  in two perpendicular directions  601 ,  602 , i.e., in two degrees of freedom, in a plane perpendicular to a longitudinal axis of the entry guide. Insertion assembly  531  extends through an opening  653  in a second floating platform  600 C. The proximal end of insertion assembly  531  is mounted to a first floating platform  600 B. Platform  600 B rides on a first set of rails  663 . Set of rails  663  is mounted on platform  600 C. A servomotor  660  is connected to platform  600 B by a first positioning element, in this aspect, by a lead screw  661  and a nut. 
     Platform  610 C rides on a second set of rails  652 . A servomotor  650  is connected to platform  600 B by a second positioning element, in this aspect, by a lead screw  651  and a nut. Servomotor  650  moves platform  600 C and consequently insertion assembly  531  in direction  601 . Servomotor  660  moves platform  600 B and consequently insertion assembly  531  in direction  602 . To add the ability to change the pitch and yaw, set of rails  652  is mounted on support that has the two degrees of freedom. The configuration of positioning mechanism  640 C is illustrative only and is not intended to be limiting to the specific elements illustrated. 
       FIGS. 7A to 7C  are a top, bottom, and oblique views respectively of one aspect of a portion of a base assembly  732  that includes a floating platform  700 . Base assembly  732  is representative of one aspect of base assembly  432 . In  FIGS. 7A to 7C , only components necessary to understand this aspect of floating platform  700  are included. 
     Floating platform  700  includes a first platform  700 A and a second platform  700 B. First platform  700 A has legs  700 L 1 ,  700 L 2  ( FIG. 7B ). Leg  700 L 1  has an outer side surface  700 L 1 S that lies in a plane that is perpendicular to a plane including an inner side surface  700 L 2 S of leg  700 L 2 . Axis  790  is along outer side surface  700 L 1 S, while axis  791  is along inner side surface  700 L 2 S. 
     Outer side surface  700 L 1 S of leg  700 L 1  is coupled to a first set of precision linear rails  752 . Set of rails  752  is affixed to an inner side surface of base assembly  732 . In  FIGS. 7B and 7C , only the distal rail in set  752  is visible. A proximal rail also is affixed to base assembly  732 . Sets of bearings  701  are mounted on outer side surface  700 L 1 S of leg  700 L 1 . Sets of bearings  701  are preloaded and ride on set of rails  752 . 
     A side surface of second platform  700 B is coupled to inner side surface  700 L 2 S of leg  700 L 2 . A proximal portion  700 B 1  of second platform  700 B extends over a proximal end surface of leg  700 L 2 . Another side surface of second platform  700 B is affixed to a portion of insertion assembly  731 . In one aspect, insertion assembly  731  includes a frame, a mid-carriage, and a distal carriage. The portion of insertion assembly  731  illustrated in  FIGS. 7A to 7C  is the frame. The mid-carriage rides on a ball screw  713  in the frame. In one aspect, ball screw  713  has a 6 mm pitch, and so ball screw  713  is back-drivable. The mid-carriage includes metal belts that drive the distal carriage. The distal carriage is attached to the surgical device assembly. 
     A second set of precision linear rails  763  is affixed to inner side surface  700 L 2 S of leg  700 L 2 . Second set of rails  763  is perpendicular to first set of rails  752 . In  FIGS. 7B and 7C , only the distal rail in set  763  is visible. A proximal rail also is affixed to inner side surface  700 L 2 S of leg  700 L 2 . Sets of bearings  702  are mounted on a side surface of platform  700 B. Sets of bearings  702  are preloaded and ride on set of rails  763 . 
     Proximal portion  700 B 1  of second platform  700 B includes a positioning element receptacle  710  that is positioned in a circular opening  715  in proximal end surface of base assembly housing  732 . As explained more completely below, a unit that includes the positioning element is mounted on housing  732  so that the positioning element, e.g., a pin, mates with positioning element receptacle  710 . In one aspect, both the pin and positioning element receptacle  710  are made of strong steel and are precisely machined to minimize backlash in the coupling of the pin in positioning element receptacle  710 . In one aspect, second platform  700 B is made of stainless steel, for example, Nitronic 60, thirty percent cold worked. However, any strong steel that operates well, e.g., does not exhibit galling or cold welding, with other steels can be used. 
       FIG. 7D  is a cut-away illustration of one aspect of positioning element receptacle  710 . A positioning element receptacle assembly  714  is mounted on proximal portion  700 B 1  of second platform  700 B. Positioning element receptacle assembly  714  includes a housing  714 H, positioning element receptacle  710 , and two bearings  711 ,  712 . Positioning element receptacle  710  is a hollow cylinder, which is open at the proximal end and open at the distal end, in this aspect. Bearing  711  is positioned between housing  714 H and positioning element receptacle  710  adjacent a proximal end of positioning element receptacle  710 . Bearing  712  is positioned between housing  714 H and positioning element receptacle  710  adjacent a distal end of positioning element receptacle  710 . Bearings  711  and  712  allow positioning element receptacle  710  to rotate relative to housing  714 H, and hence relative to second platform  700 B. The use of bearings  711  and  712  is illustrative only and is not intended to be limiting. In one aspect, bearings are not included in positioning element receptacle assembly  714 . 
     Platform  700  floats on sets of rails  752  and  763 . When the positioning element is mated with positioning receptacle  710 , movement of the positioning element moves floating platform  700  along one or both of axes  790 ,  791 . Instrument manipulator positioning system  231 E in entry guide manipulator  230 E controls the location of insertion assembly  731  by moving the positioning element to a particular location. 
       FIG. 8A  is a first example of an instrument manipulator positioning system  840 A that can be included in entry guide manipulator  230 E and coupled to floating platform  700 . Instrument manipulator positioning system  840 A includes an adjustment disk  841 A that is coupled to a fixed disk  870 A. When adjustment disk  841 A and fixed disk  870 A move synchronously together, rotation of fixed disk  870 A rolls plurality of surgical device assemblies  300  as a group, as previously described. Specifically, adjustment disk  841 A moves in synchronization with fixed disk  870 A so that rotation of fixed disk  870 A rolls the surgical device assemblies coupled to adjustment disk  841 A. 
     However, to position a shaft of an instrument for insertion into a particular entry guide, adjustment disk  841 A is first decoupled from fixed disk  870 A so that rotation of adjustment disk  841 A is not transferred to fixed disk  870 A. For a given set of entry guides, a location of the positioning element is known for the channel in each entry guide. In this example, for the given set of entry guides, the positioning element can moved to any one of five locations P 0  to P 5 , which are known. The displacements needed to move the positioning element from one location to the next are programmed in instrument manipulator positioning system  840 A. In this example, an adjustment cam  843 A defines the location of positioning element for each of five locations P 0  to P 5 . 
     A cam follower  842 A is mounted to ride on adjustment cam  843 A and in a fixed slot  844 A. Fixed slot  844 A limits the range of motion of cam follower  842 A, and so limits the motion of the positioning element. In one aspect, two types of motions are possible using cam follower  842 A—linear motion along a line and circular motion along an arc. 
     For motion along a line, cam follow  842 A includes a rod such that one end of the rod rides in adjustment cam  843 A and a second end of the rod extends, for example, into positioning element receptacle  710 . Thus, as adjustment disk  841 A rotates, the rod moves in fixed slot  844 A, which in turn moves moving platform  700  and the distal end of an instrument coupled to insertion assembly  731  along a line in a plane. 
     For motion along an arc, a link rod  845  ( FIG. 8B ) connects cam follower  842 A to a rotary disk  846 B. Positioning element  849 B is affixed to a side surface of rotary disk  846 B. As adjustment disk  841 A is rotated, a pin in the cam follower  842 A follows adjustment cam  843 A and acts like a slider crank to drive rotary disk  846 B. Output pin  894 B, the positioning element, is mounted on a side surface of disk  846 B. Thus, as rotary disk  846 B rotates, output pin  849 B moves along a constant radius arc. In one aspect, output pin  849 B is mounted in positioning element receptacle  710 , and so the shaft of the instrument coupled to floating platform  700  moves along a constant radius arc. 
     In one aspect ( FIG. 8C ), positioning element  849 C is mounted on a side of secondary disk  847 . Secondary disk  847  is geared from rotary disk  846 C. Thus, output pin  849 C follows an arc that is different from the arc followed by output pin  849 B. 
     While in  FIG. 8A  only a single fixed slot, single cam follower and single adjustment cam are shown, adjustment disk  841 A can include a fixed slot, a cam follower, and an adjustment cam for each of plurality of surgical device assemblies  300  or a fixed slot, a cam follower, and an adjustment cam for each of less than all of plurality of surgical device assemblies  300 . 
       FIG. 8D  illustrates another example of an instrument manipulator positioning system  840 D that can be included in entry guide manipulator  230 E and coupled to floating platform  700 . Instrument manipulator positioning system  840 D includes a fixed disk  870 D. Plurality of surgical device assemblies  300  is coupled to fixed disk  870 D in entry guide manipulator  230 E so that rotation of fixed disk  870 D rolls plurality of surgical device assemblies  300 , as a group. Note that in this aspect, an adjustment disk is not used, because the surgical device assemblies are moved manually to the correct location. 
     To position a shaft of an instrument for insertion into a particular entry guide, a user manually moves floating platform  700  until positioning element receptacle  710  aligns with one of five locations P 0  to P 5 , which are through holes in fixed disk  870 D. In one aspect, the outer surface of the entry guide adjacent a channel includes a number between 0 and 5 so that the operator knows which of the five locations P 0  to P 5  to select. 
     When positioning element receptacle  710  is aligned with the correct location in fixed disk  870 D, a pin is inserted through positioning element receptacle  710  into the hole in fixed disk  870 D to lock floating platform in place. In one aspect, a ball lock pin is used to lock floating platform  700  to fixed disk  870 D. While in  FIG. 8D  only a single set of locations are illustrated, fixed disk  870 D can include a set of locations for each of plurality of surgical device assemblies  300  or for each of less than all of plurality of surgical device assemblies  300 . 
       FIG. 8E  illustrates another example of an instrument manipulator positioning system  840 E that can be included in entry guide manipulator  230 E and coupled to floating platform  700 . Instrument manipulator positioning system  840 E includes an adjustment path  843 E in fixed disk  870 E. Plurality of surgical device assemblies  300  is coupled to fixed disk  870 E in entry guide manipulator  230 E so that rotation of fixed disk  870 E rolls plurality of surgical device assemblies  300 , as a group. 
     For a given set of entry guides, acceptable locations of positioning element receptacle  710  are known for a channel in each entry guide. In this example, for the given set of entry guides, the acceptable locations are along adjustment path  843 E in fixed disk  870 E. 
     However, to move a shaft of an instrument for insertion into a particular entry guide, entry guide  270 E is moved so that the longitudinal axis of entry guide  270 E is vertical. Next, a surgical instrument having a shaft is mounted onto an instrument manipulator to form a surgical device assembly, and the shaft of the surgical device assembly is inserted into a channel of entry guide  270 E. If the shaft is bent, the instrument manipulator would move along adjustment path  843 E to a position of least energy, e.g., the instrument manipulator would move to where the shaft is bent the least, and so the bend in the shaft is minimized. After the surgical device assembly has moved to the position of least energy, floating platform  700  is locked to adjustment path  843 E at that location. In one aspect, a ball lock pin is used to lock floating platform  700  to a location of adjustment path  843 E of fixed disk  870 E. While in  FIG. 8E  only a single adjustment path  843 E is illustrated, fixed disk  870 E can include a set of adjustment paths, one path each of plurality of surgical device assemblies  300  or one path for each of less than all of plurality of surgical device assemblies  300 . 
       FIG. 9  illustrates another aspect of an instrument manipulator positioning system  940  that is included in entry guide manipulator  230 E. Instrument manipulator positioning system  940  includes a lateral motion mechanism. The lateral motion mechanism includes an adjustment gear  941 , sometimes referred to as a drive gear or an adjustment ring gear, and a plurality of gearboxes  942 _ 0 ,  942 _ 1 ,  942 _ 2 ,  942 _ 3 . As described more completely below, each of gearboxes  942 _ 0 ,  942 _ 1 ,  942 _ 2 ,  942 _ 3  has an input spur gear, which engages adjustment gear  941 , and an output pin. The output pin is the positioning element described above. Each positioning element mates with a positioning element receptacle in a floating platform, e.g., positioning element receptacle  710  in floating platform  700 . 
     Each of gearboxes  942 _ 0 ,  942 _ 1 ,  942 _ 2 ,  942 _ 3  is installed with a release pin  943 _ 0 ,  943 _ 1 ,  943 _ 2 ,  943 _ 3 . The release pin locks each gearbox during installation, which ensures that the gearboxes are properly synchronized. In  FIG. 9 , release pin  943 _ 1  has been removed from gearbox  942 _ 1 . 
     In one aspect, turning adjustment gear  941  causes each of gearboxes  942 _ 0 ,  942 _ 1 ,  942 _ 2 ,  942 _ 3  to move the positioning element so that the floating platform coupled to the positioning element moves on a specific trajectory. As described previously, an insertion assembly is attached to the floating platform and a surgical device assembly is attached to the insertion assembly. Thus, as the positioning element moves the floating platform on the specific trajectory, the distal end of the surgical instrument shaft follows that specific trajectory. 
     In  FIG. 9 , gearboxes  942 _ 0 ,  942 _ 1 ,  942 _ 2 ,  942 _ 3  are representative of a set of gearboxes. In  FIGS. 10A to 10D , a first set of gearboxes is illustrated. In  FIGS. 11A to 11K , a second set of gearboxes is illustrated. The combination of gearboxes in a set is illustrative only and is not intended to be limiting. As explained more completely below, the particular combination of gearboxes used in a set of gearboxes for  FIG. 9  is determined by the entry guides and instruments used with patient side support system  210 E. 
     Also, the use of four gearbox sets is illustrative only and is not intended to be limiting. In view of this disclosure, a set of gearboxes can include any number of gearboxes, e.g., one for each manipulator assembly  240  that is to be automatically positioned. With a set of four gearboxes, each of the four manipulator assemblies in  FIGS. 3A and 3B  is automatically positioned. However, as explained above, some aspects may include more than four manipulator assemblies (see  FIG. 5F ) in a system, and so if all the manipulator assemblies are automatically positioned, the set of gearboxes can include more than four gearboxes in such a system. Similarly, if less than all of the manipulator assemblies were automatically positioned, the number of gearboxes in a set would be less than the total number of manipulator assemblies.  FIG. 9  is not repeated for each of the possible combinations of gearboxes in a set, because in view of this disclosure, one knowledgeable in the field can select gearboxes for the number of manipulator assemblies that are automatically positioned to accommodate different instruments and/or guide tubes, e.g., the number of gearboxes in a set can vary from one up to the total number of manipulator assemblies in the system. 
     In one aspect, two types of gearboxes are used in a first set of gearboxes. A first gearbox moves the positioning element on a circular trajectory. A second gearbox moves the positioning element on a linear trajectory. In this aspect, a linear trajectory gearbox  942 _ 0 _ 1  ( FIGS. 10C and 10D ) is used for gearbox  942 _ 0  ( FIG. 9 ), while a circular trajectory gearbox  942  ( FIGS. 10A and 10B ) is used for each of gearboxes  942 _ 1 ,  942 _ 2 ,  942 _ 3  ( FIG. 9 ). This combination of gearboxes is illustrative only and is not intended to be limiting. As explained more completely below, the particular combination of gearboxes used in  FIG. 9  is determined by the entry guides and instruments used with patient side support system  210 E. 
       FIG. 10A  is a proximal view of a gearbox  942 . In this aspect, gearbox  942  represents each of gearboxes  942 _ 1 ,  942 _ 2 , and  942 _ 3  in  FIG. 9 , which have a circular trajectory.  FIG. 10B  is a distal view of gearbox  942 . In  FIGS. 10A and 10B , parts of the gearbox housing have been removed. 
     Gearbox  942  has a housing that supports a gear train including an input gear  1001 _A and an output gear  1002 _A. Above, input gear  1001 _A was referred to as an input spur gear. 
     An output pin  1049 _B, e.g., a positioning element, is mounted on a distal side surface  1002 S_B of output gear  1002 _A. In this aspect, output pin  1049 _B is mounted on output gear  1002 _A offset from the center of rotation of output gear  1002 _A. Thus, the trajectory of output pin  1049 _B and consequently, the shaft of the surgical instrument, is a constant radius arc. In one aspect, output pin  1049 _B is a stainless steel pin, for example, Nitronic 60, thirty percent cold worked. However, any strong steel that operates well, i.e., does not exhibit galling or cold welding, with other steels can be used. 
     Output pin  1049 _B extends distally from surface  1002 S_B through an opening  1044 _B in a distal side  1032 S_B of the housing. A shape of opening  1044 _B is selected to control the range of motion of output pin  1049 _B. Thus, opening  1044 _B is a motion stop for output pin  1049 _B. 
       FIG. 10C  is a proximal view of gearbox  942 _ 0 _ 1 , which is a linear trajectory gearbox. Gearbox  942 _ 0 _ 1  is an example of gearbox  942 _ 0  ( FIG. 9 ).  FIG. 10D  is a distal view of gearbox  942 _ 0 _ 1 . In  FIGS. 10C and 10D , the gearbox housing is transparent so that the elements inside the housing can be seen. 
     Gearbox  942 _ 0 _ 1  has a housing that supports a gear train including an input gear  1001 _C and a cam gear  1002 _C. Cam gear  1002 _C includes an adjustment cam  1043  that is a slot machined into cam gear  1002 _C from distal surface  1002 S_D ( FIG. 10D ). Thus, adjustment cam  1043  is sometimes referred to as cam slot  1043 . 
     A proximal end of an output pin  1049 _D, e.g., a proximal end of a positioning element, rides in adjustment cam  1043 . Output pin  1049 _D is mounted in a carriage  1005  that rides on a pair on linear rails  1052 . Linear rails  1052  are mounted on an inner distal surface of the housing. In one aspect, output pin  1049 _D is a stainless steel pin, for example, Nitronic 60, thirty percent cold worked. However, any strong steel that operates well, i.e., does not exhibit galling or cold welding, with other steels can be used. 
     Output pin  1049 _D extends distally through a fixed slot  1044 _D in a distal side  1032 S_D of the housing. The size of fixed slot  1044 _D is selected to control the range of motion of output pin  1049 _D. Thus, fixed slot  1044 _D is a motion stop for output pin  1049 _D. 
     As input gear  1001 _C drives cam gear  1002 _C, adjustment cam  1043  moves output pin  1049 _D. Normally, there would be a fair amount of friction between output pin  1049 _D and cam slot  1043  as cam gear  1002 _C rotates. However, in one aspect, a pair of bearings is mounted on output pin  1049 _D where output pin  1049 _D sits in cam slot  1043  so that gearbox  942 _ 0 _ 1  transmits the pin motion through bearing rolling action rather than sliding motion. 
     In gearbox  942 _ 0 _ 1 , the position of output pin  1049 _D is guided by the profile of adjustment cam  1043 _D. However, carriage  1005  and linear rails  1052  restrict the movement of output pin  1049 _D to motion on a straight line. This configuration has the benefit of being reversible, which makes the ordering of the output pin positions more flexible. 
     In another aspect, a second set of gearboxes includes four different gearboxes as illustrated in  FIGS. 11A to 11K .  FIG. 11A  is a proximal view of gearbox  942 _ 0 _ 2 , which is a linear trajectory gearbox. Gearbox  942 _ 0 _ 2  is an example of  942 _ 0  ( FIG. 9 ). Gearbox  942 _ 0 _ 2  is a first gearbox in the second set of gearboxes, and typically is used to position a camera instrument.  FIG. 11B  is a distal view of gearbox  942 _ 0 _ 2 . In  FIGS. 11A and 11B , the gearbox housing is transparent so that the elements inside the housing can be seen. In  FIG. 11A , release pin  943 _ 0 _ 2  has been removed from gearbox  942 _ 0 _ 2 , and so is not shown. 
     Gearbox  942 _ 0 _ 2  has a housing that supports a gear train including an input gear  1101 _A and a cam gear  1102 _A. Cam gear  1102 _A includes an adjustment cam  1143 _B that is a slot machined into cam gear  1102 _A from distal surface  1102 DS_B ( FIG. 11B ). Thus, adjustment cam  1143 _B is sometimes referred to as cam slot  1143 _B. 
     A proximal end of an output pin  1149 _B is coupled to a cam follower, e.g., a proximal end of a positioning element is coupled to a cam follower, which rides in adjustment cam  1143 _B. Output pin  1149 _B extends distally through a fixed slot  1144 _B in a distal side  1132 DS_B of the housing. The size of fixed slot  1144 _B is selected based on the range of motion of output pin  1149 _B. The width of fixed slot  1144 _B is wide enough to accommodate the part of output pin output pin  1149 _B that rolls on an edge surface of the slot plus a tolerance. 
     In this aspect, a stop pin  1103 _A extends in a proximal direction from proximal surface  1102 PS_A of cam gear  1102 _A. Stop pin  1103 _A rides in a slot  1104 _A in an interior surface of a proximal side  1132 PS_A of the housing. Stop pin  1103 _A in combination with slot  1104 _A limits the range of rotation of cam gear  1102 _A, and so the combination is a range of motion stop. 
     As input gear  1101 _A rotates cam gear  1102 _A, adjustment cam  1143 _B moves output pin  1149 _B in slot  1144 _B. The position of output pin  1149 _B is guided by the profile of adjustment cam  1143 _D. However, slot  1144 _B restrains the movement of output pin  1149 _B to motion on a straight line. See  FIG. 18C . 
       FIG. 11C  is a proximal view of gearbox  942 _ 1 _ 2 , which is a first two degree-of-freedom trajectory gearbox. Gearbox  942 _ 1 _ 2  is an example of  942 _ 1  ( FIG. 9 ). 
     Gearbox  942 _ 1 _ 2  is a second gearbox in the second set of gearboxes.  FIG. 11D  is a distal view of gearbox  942 _ 0 _ 2 . In  FIGS. 11C and 11D , the gearbox housing is transparent so that the elements inside the housing can be seen. In  FIG. 11C , release pin  943 _ 1 _ 2  has been removed from gearbox  942 _ 1 _ 2 , and so is not shown. 
     Gearbox  942 _ 1 _ 2  has a housing that supports a gear train including an input gear  1101 _C and a cam gear  1102 _C. Cam gear  1102 _C includes an adjustment cam  1143 _D that is a slot machined into cam gear  1102 _C from distal surface  1102 DS_D ( FIG. 11B ). Thus, adjustment cam  1143 _D is sometimes referred to as cam slot  1143 _D. 
     A proximal end of an output pin  1149 _D is coupled to a cam follower, e.g., a proximal end of a positioning element is coupled to a cam follower, which rides in adjustment cam  1143 _D. Output pin  1149 _D extends distally through a fixed slot  1144 _D in a distal side  1132 DS_D of the housing. The size of fixed slot  1144 _D is selected based on the range of motion of output pin  1149 _D. The width of fixed slot  1144 _D is wide enough to accommodate the part of output pin output pin  1149 _D that rolls on an edge surface of the slot plus a tolerance. 
     In this aspect, a stop pin  1103 _C extends in a proximal direction from proximal surface  1102 PS_C of cam gear  1102 _C. Stop pin  1103 _C rides in a slot  1104 _C in an interior surface of a proximal side  1132 PS_C of the housing. Stop pin  1103 _C in combination with slot  1104 _C limits the range of rotation of cam gear  1102 _C, and so the combination is a range of motion stop. 
     As input gear  1101 _C rotates cam gear  1102 _C, adjustment cam  1143 _D moves output pin  1149 _D in slot  1144 _D. The position of output pin  1149 _D is guided by the profile of adjustment cam  1143 _D. However, slot  1144 _D restrains the movement of output pin  1149 _D to motion on a combination of two arcs. Output pin  1149 _D has two degrees of freedom. See  FIG. 18E . 
       FIGS. 11E and 11F  are proximal views of gearbox  942 _ 2 _ 2 , which is a second two degree-of-freedom trajectory gearbox. Gearbox  942 _ 2 _ 2  is an example of  942 _ 2  ( FIG. 9 ). Gearbox  942 _ 2 _ 2  is a third gearbox in the second set of gearboxes.  FIG. 11G  is a distal view of gearbox  942 _ 2 _ 2 .  FIG. 11H  is a cross-sectional view of gearbox  942 _ 2 _ 2 . In  FIGS. 11E, 11F , and  11 G, the gearbox housing is transparent so that the elements inside the housing can be seen. 
     Gearbox  942 _ 2 _ 2  has a housing that supports a gear train including an input gear  1101 _E and a cam gear  1102 _E. Cam gear  1102 _E includes an adjustment cam  1143 _G that is a slot machined into cam gear  1102 _E from distal surface  1102 DS_G ( FIG. 11B ). Thus, adjustment cam  1143 _G is sometimes referred to as cam slot  1143 _G. 
     In  FIG. 11E , release pin  943 _ 2 _ 2  is shown inserted in gearbox  942 _ 2 _ 2 . As described previously, each release pin, e.g., release pin  943 _ 2 _ 2 , locks its gearbox during installation, which ensures that the gearbox is properly synchronized with adjustment gear  941 . In  FIG. 11F , release pin  943 _ 2 _ 2  has been removed from gearbox  942 _ 2 _ 2 . 
     A proximal end of an output pin  1149 _G is coupled to a cam follower, e.g., a proximal end of a positioning element is coupled to a cam follower, which rides in adjustment cam  1143 _G. Output pin  1149 _G extends distally through a fixed slot  1144 _G in a distal side  1132 DS_G of the housing. The size of fixed slot  1144 _G is selected based on the range of motion of output pin  1149 _G. The width of fixed slot  1144 _G is wide enough to accommodate the part of output pin  1149 _G that rolls on an edge surface of the slot plus a tolerance. 
     In this aspect, a stop pin  1103 _E extends in a proximal direction from proximal surface  1102 PS_E of cam gear  1102 _E. Stop pin  1103 _E rides in a slot  1104 _E in an interior surface of a proximal side  1132 PS_E of the housing. Stop pin  1103 _E in combination with slot  1104 _E limits the range of rotation of cam gear  1102 _A, and so the combination is a range of motion stop. 
     As input gear  1101 _E rotates cam gear  1102 _E, adjustment cam  1143 _G moves output pin  1149 _G in slot  1144 _G. The position of output pin  1149 _G is guided by the profile of adjustment cam  1143 _G. However, slot  1144 _G restrains the movement of output pin  1149 _G to motion on a combination of a line and an arc. Output pin  1149 _G has two degrees of freedom. See  FIG. 18G . 
     Each of the other gearboxes in the second set, i.e., gearboxes  942 _ 0 _ 2 ,  942 _ 1 _ 2 , and  942 _ 3 _ 2  has a cross-sectional view similar to the cross sectional view for gearbox  942 _ 2 _ 2  in  FIG. 11H . Thus, a cross-sectional view of each gearboxes  942 _ 0 _ 2 ,  942 _ 1 _ 2 , and  942 _ 3 _ 2  would not add any additional information, and so is not presented. As shown in  FIG. 11H , in this aspect, output pin  1149 _G is coupled to a cam follower  1160  by a bushing  1161 . Cam follower  1160  rides in cam slot  1104 _E. In this aspect, no bearings are used to support output pin  1149 _G, because output pin  1149 _G is supported by bearings  711  and  712  in positioning element receptacle assembly  714  ( FIG. 7D ). In this aspect, the housing of gearbox  942 _ 2 _ 2  includes a base  1170 _G and a lid  1171 _G. 
       FIG. 11I  is a proximal view of gearbox  942 _ 3 _ 2 , which is a third two degree-of-freedom trajectory gearbox. Gearbox  942 _ 3 _ 2  is an example of  942 _ 3  ( FIG. 9 ). 
     Gearbox  942 _ 3 _ 2  is a fourth gearbox in the second set of gearboxes.  FIG. 11J  is a distal view of gearbox  942 _ 3 _ 2 . In  FIGS. 11I and 11J , the gearbox housing is transparent so that the elements inside the housing can be seen. In  FIG. 11I , release pin  943 _ 3 _ 2  has been removed from gearbox  942 _ 3 _ 2 , and so is not shown. 
     Gearbox  942 _ 3 _ 2  has a housing that supports a gear train including a reversing idler gear,  1108 _I, an input gear  1101 _I and a cam gear  1102 _I. Reversing idler gear  1108 _I rides on adjustment gear  941 , and drives cam gear  1102 _I. Reversing idler gear  1108 _I is used, in this aspect, to assure that the manipulator positioning system does not enter an unstable state. Cam gear  1102 _I includes an adjustment cam  1143 _J that is a slot machined into cam gear  1102 _I from distal surface  1102 DS_J ( FIG. 11J ). Thus, adjustment cam  1143 _J is sometimes referred to as cam slot  1143 _J. 
     A proximal end of an output pin  1149 _J is coupled to a cam follower, e.g., a proximal end of a positioning element is coupled to a cam follower, which rides in adjustment cam  1143 _J. Output pin  1149 _J extends distally through a fixed slot  1144 _J in a distal side  1132 DS_J of the housing. The size of fixed slot  1144 _J is selected based on the range of motion of output pin  1149 _J. The width of fixed slot  1144 _J is wide enough to accommodate the part of output pin output pin  1149 _J that rolls on an edge surface of the slot plus a tolerance. 
     In this aspect, a stop pin  1103 _I extends in a proximal direction from proximal surface  1102 PS_I of cam gear  1102 _I. Stop pin  1103 _I rides in a slot  1104 _I in an interior surface of a proximal side  1132 PS_I of the housing. Stop pin  1103 _I in combination with slot  1104 _I limits the range of rotation of cam gear  1102 _I, and so the combination is a range of motion stop. 
     As input gear  1101 _I rotates cam gear  1102 _I, adjustment cam  1143 _J moves output pin  1149 _J in slot  1144 _J. The position of output pin  1149 _J is guided by the profile of adjustment cam  1143 _J. However, slot  1144 _J restrains the movement of output pin  1149 _J to motion on a combination of two arcs. Output pin  1149 _J has two degrees of freedom. See  FIG. 18I . 
       FIG. 11K  is a more detailed diagram of cam gear  1102 _I. In one aspect, output pin  1149 _J is moved to one of seven positions by rotation of cam gear  1102 _I. The seven positions of output pin  1149 _J are represented by dotted lines  1149 _J_ 1  to  1149 _J_ 7  in cam slot  1143 _J. The lighter colored lines in  FIG. 11K  are working lines and are not essential. 
     At each location where output pin  1149 _J stops in cam slot  1143 _J, the cam surface is flat, i.e., the flat surface of the cam is perpendicular to a radial line through the center of cam gear  1102 _I. This prevents back driving of cam gear  1102 _I. In some situations, surgical device assemblies  300  may be positioned such that the weight of a surgical device assembly transfers a force to the corresponding output pin for that assembly. The flat spots at the stop locations of output pin  1149 _J assures that the only force transferred by the pin to cam gear  1102 _I is a radial force through the center of cam gear  1102 _I, and so back driving of cam gear  1102 _I is not a problem. Cam gear  1102 _I is also representative of the cam gears in each of the other gearboxes in the second set although the cam surfaces are not the same in each gearbox. 
     Another feature of cam gear  1102 _I is that output pin  1149 _J is moved to the appropriate stop position, as shown in  FIG. 11K , by even increments of rotation of cam gear  1102 . In this example, cam gear  1102 _I is rotated ninety degrees to move output pin  1149 _J from location  1149 _J_ 1 —the draping position—to location  1149 _J_ 2  and then cam gear  1102 _I is rotated forty-five degrees to move output pin  1149 _J to each subsequent stop location, i.e., locations  1149 _J_ 3  to  1149 _J_ 7 . Stop locations  1149 _J_ 2  to  1149 _J_ 7  are not at even increments in  FIG. 11K  because while cam gear  1102 _I rotates in even increments, output pin  1149 _J is constrained to move in cam slot  1143 _J. 
     In one aspect, each of the gearboxes in the second set of gearboxes is constructed using the same materials. The base is made from 2024-T4 aluminum. The lid is made from 6061-T6 aluminum. All of the gears including the cam gear are made from 2024-T4 aluminum. In one aspect, each of the output pins is a stainless steel pin, for example, Nitronic 60, thirty percent cold worked, or 416 stainless steel. However, any strong steel that operates well, i.e., does not exhibit galling or cold welding, with other steels can be used. The materials mentioned here are illustrative only and are not intended to be limiting. Other equivalent metals and/or plastics could also be used. 
     In one aspect, a roll system and an instrument manipulator positioning system are both contained in entry guide manipulator  230 E. The roll system includes a roll ring gear that is used to roll plurality of surgical device assemblies  300  ( FIG. 3B ). Adjustment ring gear  941  of instrument manipulator positioning system  940  interfaces with an input gear in each gearbox, e.g., gearboxes  942 _ 0  to  942 _ 3 . 
     The output pin in each of the gearboxes is moved, for example, in one of two ways. The roll ring gear is held stationary, and the adjustment ring gear is rotated, or the adjustment ring gear is held stationary and the roll ring gear rotated. In general however, proper positioning can be obtained if one of the two gears is moved differentially with respect to the other gear, e.g., the two gears are moved with different angular velocity. 
       FIGS. 12A to 12D  illustrate an example of an entry guide manipulator in which the roll ring gear is held stationary and the adjustment ring gear is rotated to move simultaneously each of the surgical device assemblies so that its instrument shaft is in the appropriate position for passing through a channel in an entry guide with damaging the surgical instrument.  FIGS. 13A to 13D  illustrate an example of an entry guide manipulator in which the adjustment ring gear is held stationary and the roll ring gear is rotated to move simultaneously each of the surgical device assemblies so that its instrument shaft is in the appropriate position for passing through a channel in an entry guide without damaging the surgical instrument. In both examples, during normal operations, the rotation of the roll ring gear and adjustment ring gear is synchronous, which means that that the two ring gears rotate together at the same angular velocity. 
     These examples are illustrative only and are not intended to be limiting. In view of this disclosure, other methods that move the roll ring gear and the adjustment ring gear asynchronously, e.g., move the two gears differentially, can be used to move the surgical device assemblies to the appropriate positions to enable passing their shafts through an entry guide, e.g., the two ring gears could be rotated at different angular velocities. 
       FIG. 12A  is a schematic diagram of another aspect of an entry guide manipulator  230 D with a roll system  1210  and an instrument manipulator positioning system  1220 . Roll system  1210  rolls all of the surgical instruments assemblies coupled to entry guide manipulator  230 D as a group. Instrument manipulator positioning system  1220  simultaneously moves all or some of the surgical instruments assemblies coupled to entry guide manipulator  230 D, as needed, to align the shafts of the surgical device assemblies with different channels in an entry guide so that the shafts can enter and pass through the entry guide without exceeding the stress limits on the shafts if the shafts are bent upon entry to the entry guide. 
     A drive assembly  1290  is coupled to roll system  1210  and to instrument manipulator positioning system  1220 . A surgical device assembly  1230  is coupled to manipulator position system  1220 . While it not shown in  FIG. 12A , surgical device assembly  1230  is also coupled to roll system  1210 . 
     Roll system  1210  includes a roll ring gear  1270 . Roll system  1210  includes other components, but these components are not shown in the drawings to facilitate the description of drive assembly  1290 . Instrument manipulator positioning system  1220  includes an adjustment ring gear  1241  and a gearbox  942 D. Gearbox  942 D includes a positioning element. Surgical device assembly  1230  is coupled to the positioning element in gearbox  942 D, for example as described above, so that when the positioning element moves the shaft of the instrument also is moved. When gearbox  942 D moves the positioning element, the position the shaft of surgical device assembly  1230  moves in a plane, which in one aspect is a lateral plane that is perpendicular to a longitudinal axis of the entry guide. 
     In  FIG. 12A , only a single gearbox  942 D is shown for ease of discussion. However, adjustment ring gear  1241  engages a plurality of gearboxes in manner equivalent to that illustrated in  FIG. 9  and each gearbox is couplable to a surgical device assembly. Surgical device assembly  1230  is equivalent to a surgical device in the plurality of surgical device assemblies  300  described above, and so that description is not repeated here. 
     Drive assembly  1290  includes a roll motor assembly  1291  that is coupled to roll ring gear  1270  and to adjustment ring gear  1241 . Adjustment ring gear  1241  is sometimes referred to as an adjustment gear. In a roll operation, roll motor assembly  1291  drives roll ring gear  1270  and adjustment ring gear  1241  so that the rotation of the two gears is synchronized. 
     A brake  1292  and a clutch  1295  are coupled to roll ring gear  1270 . An adjustment gear drive assembly  1293  is coupled to adjustment ring gear  1241 . In this aspect, when clutch  1295  is disengaged by moving a knob  1294  with a linear motion, adjustment gear drive assembly  1293  can then be manually operated by turning knob  1294 . 
     In a manipulator position adjustment process, knob  1294  disengages clutch  1295 , and brake  1292  prevents roll ring gear  1270  from turning. Turning knob  1294  causes adjustment gear drive assembly  1293  to rotate adjustment ring gear  1241 . Because roll ring gear  1270  is held stationary, gearbox  942 D does not move. However, the rotation of adjustment gear drive assembly  1293  moves the positioning element in gearbox  942 D, as described above, which in turn changes the position of the shaft of surgical device assembly  1230 . The differential motion between roll ring gear  1270  and adjustment ring gear  1241  controls the movement of the positioning element in gearbox  942 D. 
       FIG. 12B  illustrates one configuration with roll ring gear  1270  and adjustment ring gear  1241  mounted in a housing  1232  of entry guide manipulator  230 D. In one aspect, adjustment ring gear  1241  can be either adjustment disk  841  or adjustment gear  941 . 
     Roll ring gear  1270  rotates inside housing  1232  on a four-point contact bearing, in one aspect. Adjustment ring gear  1241  is free to rotate on roll ring gear  1270 , and is driven by output gear  1202  ( FIG. 12C ) in a planetary gear differential mechanism  1250 .  FIG. 12C  is a cross sectional view of one aspect of planetary gear differential mechanism  1250 , while  FIG. 12D  is a bottom view of planetary gear differential mechanism  1250 . Planetary gear differential mechanism  1250  is an example of an implementation of clutch  1295  and adjustment gear drive assembly  1293 . 
     Motion of adjustment ring gear  1241  relative to roll ring gear  1270  is controlled by a user through a single manual knob  1294  located on housing  1232 . Knob  1294  is mounted on a spline shaft  1218 . 
     To drive adjustment ring gear  1241 , the user pulls knob  1294  against knob preload spring  1219  to disengage knob  1294  from lock  1213  and then rotates knob  1294 . When used this way, roll ring gear  1270  is disengaged from knob  1294  by clutch  1295  and brake  1292  prevents motion of roll ring gear  1270  (which effectively locks sun gear  1217 ), and the rotation of knob  1294  rotates planet carrier  1215 . The rotation of planet carrier  1215  rotates planet gears  1216  that in turn drives ring gear  1214 . Ring gear  1214  drives output gear  1202 . The teeth on output gear  1202  mesh with teeth on the perimeter of adjustment ring gear  1241 . Thus, the engagement of knob  1294  locks roll ring gear  1270 , and the rotation of knob  1294  rotates adjustment ring gear  1241 . The rotation of adjustment ring gear  1241  moves the positioning elements as described above. Gears  1201  and  1220  are idler gears configured to assist in proper operation of the structure. 
     The gear ratios of all components in planetary gear differential mechanism  1250  are selected to ensure that adjustment ring gear  1241  and roll ring gear  1270  are synchronized when the knob  1294  is locked and clutch  1295  is engaged. The gear ratios are also selected to get an adequate relationship between the knob rotation and adjustment disk rotation. In one aspect, positions on knob  1294  corresponding to positions of the positioning elements are communicated to the user as a ball-detent click, and the positions may have some over-center feel as well. 
     In this aspect, manual control of adjustment ring gear  1241  is used. In another aspect, knob  1294  is eliminated and spline shaft  1218  is coupled to a shaft of a servomotor or to a solenoid. The servomotor is configured to push or pull against preload spring  1219  to lock roll ring gear  1270  and engage adjustment ring gear  1241 , as described above for manual operation. 
       FIG. 13A  is a schematic diagram of another aspect of an entry guide manipulator  230 E with a roll system  1310  and an instrument manipulator positioning system  1320 . Roll system  1310  rolls all of the instruments assemblies coupled to system  1310  as a group. Instrument manipulator positioning system  1320  simultaneously positions all or some of the instruments assemblies coupled to system  1310  to enable insertion of shafts of the surgical device assemblies into different channels in an entry guide without damaging the instruments. 
     A drive assembly  1390  is coupled to roll system  1310  and to instrument manipulator positioning system  1320 . A surgical device assembly  1330  is coupled to manipulator position system  1320 . While it not shown in  FIG. 13A , surgical device assembly  1330  is also coupled to roll system  1310 . 
     Roll system  1310  includes a roll ring gear  1370 . Instrument manipulator positioning system  1320  includes an adjustment ring gear  1341  and a gearbox  942 D. Gearbox  942 D includes a positioning element. Surgical device assembly  1330  is coupled to the positioning element in gearbox  942 D, for example as described above. When gearbox  942 D moves the positioning element, the position of the shaft of surgical device assembly  1330  moves in a plane, which in one aspect is a lateral plane. The lateral plane is perpendicular to the axis of rotation of entry guide manipulator  230 E. 
     In  FIG. 13A , only a single gearbox  942 D is shown for ease of discussion. However, adjustment ring gear  1341  engages a plurality of gearboxes in manner equivalent to that illustrated in  FIG. 9  and each gearbox is couplable to a surgical device assembly. Surgical device assembly  1330  is equivalent to surgical device assembly  300  described above, and so that description is not repeated here. 
     In this aspect, drive assembly  1390  includes a roll motor assembly  1391 , a clutch  1392 , and a brake  1393 . Roll motor assembly  1391  is directly coupled to roll ring gear  1370  and is directly coupled to adjustment ring gear  1341  through clutch  1392 , when clutch  1392  is engaged. When clutch  1392  is dis-engaged, roll motor assembly  1391  is not coupled to adjustment ring gear  1341 . 
     Brake  1393  is directly coupled to adjustment ring gear  1341 . When brake  1393  is engaged, brake  1393  prevents adjustment ring gear  1341  from turning. When brake  1393  is disengaged, adjustment ring gear  1341  can rotate. 
     In one aspect, clutch  1392  and brake  1393  are implemented as electromagnetic components. Clutch  1392  is implemented so that when power is applied to clutch  1392 , clutch  1392  is released, i.e., dis-engaged, and when there is no power applied, clutch  1392  is engaged. Brake  1393  is implemented so that when power is applied, brake  1393  is released, and where there is no power brake is engaged. 
     Entry guide manipulator  230 E, in one aspect, has at least three modes of operation: a roll mode, a fault mode, and an instrument manipulator positioning system adjustment mode. In the roll mode, the surgical device assemblies coupled to roll system  1310  are rolled as a group. In the fault mode, both roll system  1310  and instrument manipulator positioning system  1320  are disabled. In the instrument manipulator positioning system adjustment mode, each surgical device assembly coupled to system  1320  is individually moved so that its instrument shaft is in the appropriate position for passing through an entry guide without exceeding the stress limits for that shaft. Table 1 is an example of how the control system powers clutch  1392  and brake  1393  in each mode of operation. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Mode 
                 Brake 1393 
                 Clutch 1392 
               
               
                   
               
             
            
               
                 Roll 
                 Energized = released 
                 Not-energized = engaged 
               
               
                 Fault 
                 Not-energized = engaged 
                 Not-energized = engaged 
               
               
                 Adjustment 
                 Not-energized = engaged 
                 Energized = released 
               
               
                   
               
            
           
         
       
     
     Returning to  FIG. 13A , in the roll mode, brake  1393  is released and clutch  1392  is engaged. Thus, roll motor assembly  1391  drives roll ring gear  1370  and adjustment ring gear  1341  so that the rotation of the two ring gears is synchronous. 
     In the fault mode, power is cut to both clutch  1392  and brake  1393 . Thus, both brake  1393  and clutch  1392  are engaged. Brake  1393  prevents adjustment ring gear  1341  from rotating. Since roll ring gear  1370  is connected to adjustment ring gear  1341  through engaged clutch  1392 , roll ring gear  1370  is also prevented from rotating by brake  1393 . Thus, in the fault mode, any motion of either ring gear is inhibited. 
     In the adjustment mode, clutch  1392  is released, and brake  1393  is engaged. Thus, adjustment ring gear  1341  is preventing from rotating, while roll motor assembly  1391  rotates roll ring gear  1370 . Roll ring gear  1370  is rotated until the difference in position between adjustment ring gear  1341  and roll ring gear  1370  is such that the instrument shafts are properly positioned. 
     In the prior example of  FIGS. 12A to 12D , the gearboxes were held stationary, and motion of adjustment ring gear  1241  turned the input gears of the gearboxes to position the output pins. Here, the gearboxes are rotated relative to adjustment ring gear  1341  and this motion turns the gears in the gearbox so that that the output pins, the positioning elements, are moved to the correct location. 
       FIGS. 13B to 13D  are more detailed illustrations of one aspect of implementing entry guide manipulator  230 E of  FIG. 13A .  FIG. 13B  is an illustration of entry guide manipulator  230 E with the cover removed. Gearboxes  942 _ 1 ,  942 _ 2  (see  FIG. 9 ), base assemblies  732 _ 1 ,  732 _ 3  (see  FIGS. 7A to 7C ), and insertion assemblies  731 _ 1 ,  731 - 3  (see  FIGS. 7A to 7C ) are visible in  FIG. 13B . The outer gear teeth of adjustment ring gear  1341  and the gear teeth of roll ring gear  1370  are also visible in  FIG. 13B . The outer diameter of adjustment ring gear  1341  is the same as the outer diameter as roll ring  1370 . Digital potentiometer  1350  measures the absolute position of roll ring gear  2370  with respect to a mechanical ground of entry guide manipulator  230 E. 
       FIG. 13C  is a cut away illustration that shows the interface between adjustment ring gear  1341  and input gear  1001  of gearbox  942 _ 1 . The gear teeth of input gear  1001  engage the inner gear teeth of adjustment ring gear  1341 . 
       FIG. 13D  is a cut away illustration of a drive assembly  1390  for roll gear assembly  1310  and instrument manipulator positioning system  1320 . Motor assembly  1391 , clutch  1392 , brake  1393 , and a second potentiometer  1351  are mounted in a housing  1394  of drive assembly  1390 . As used herein, a clutch connects and disconnects one shaft to and from another shaft, and a brake connects and disconnects a shaft to and from ground. 
     Motor output gear  1317  drives roll gear train  1371 , and roll gear train  1371  drives roll ring gear  1370 . Roll gear train  1371  includes a roll input gear  1372  and a roll output gear  1373 . Roll input gear  1372  and a roll output gear  1373  spin together. 
     Adjustment gear train  1360  is coupled to roll gear train  1371  by clutch  1392 . Sometimes adjustment gear train  1360  is referred to as instrument manipulator positioning system gear train  1360 . Adjustment gear train  1360  drives adjustment ring gear  1341 . Adjustment gear train  1360  includes an adjustment input gear  1361  and an adjustment output gear  1362 . Adjustment input gear  1361  and adjustment output gear  1362  spin together. 
     The ratios of the gears in roll gear train  1371  and in adjustment gear train  1360  are the same. Thus, when both gear trains  1371  and  1360  are driven by motor  1391 , roll ring gear  1370  and adjustment ring gear  1341  rotate synchronously, e.g., roll ring gear  1370  and adjustment ring gear  1341  spin one to one. 
     In this example, roll motor assembly  1391  is a compact high torque slotless brushless direct current motor  1312  with a shaft  1313 . Roll motor assembly  1391  includes a hall sensor assembly  1314  and an encoder  1315 . Motor shaft  1313  is coupled to a harmonic gear drive  1316 . Harmonic gear drive  1316  is coupled to a motor output gear  1317 . 
     As is known to those knowledgeable in the field, harmonic gear drive  1316  includes three components: a wave generator, a flexspline, and a circular spline. Harmonic gear drive  1316  has zero backlash, high positional accuracy relative to other gearing technologies, and a high torque-to-weight ratio relative to other gearing technologies. 
     Motor output gear  1317  drives roll input gear  1372  in a roll system gear train  1371 . Roll input gear  1372  is mounted on a pair of bearings. The pair of bearings is mounted on shaft  1331  of clutch  1392 . A hub  1335  of clutch  1392  is affixed to roll input gear  1372  in roll system gear train  1371 . 
     Shaft  1331  of clutch  1392  is rotatably mounted in housing  1394  using a bearing on each end of shaft  1331 . Adjustment input gear  1361  of instrument manipulator positioning system gear train  1360  is fixedly mounted on shaft  1331  so that as shaft  1331  spins, adjustment input gear  1361  rotates. 
     Hub  1335  of clutch  1392  is mounted on shaft  1331  through a hub on roll input gear  1372 . Armature  1334  contains permanent magnets and is connected mechanically to hub  1335  by leaf springs so that armature  1334 , hub  1335 , and roll input gear  1372  rotate as a unit about shaft  1331 . 
     Rotor  1333  is mounted on shaft  1331  so that when rotor  1331  spins, shaft  1331  spins also. When there is no power applied to electromagnetic coil  1332 , permanent magnet armature  1334  also attaches to rotor  1333  and so adjustment input gear  1361  rotates synchronously with roll input gear  1372  when brake  1393  is not engaged. 
     When power is applied to electromagnetic coil  1332 , the current flow through electromagnetic coil  1332  creates a magnetic field that magnetizes rotor  1333  so that there is no longer any magnetic attachment between rotor  1333  and armature  1334 . The leaf springs connecting armature  1334  and hub  1335  pull the armature  1334  upward and separate the armature  1334  from the rotor  1333 . Thus, armature  1334  and rotor  1333  are disconnected and shaft  1331  is no longer coupled to roll input gear  1372 . This allows roll input gear  1372  to rotate without rotating adjustment input gear  1361  as clutch  1392  is disengaged. 
     Roll input gear  1372  drives roll output gear  1373  of roll system gear train  1371 . Roll output gear  1373  is mounted on a pair of bearings. The pair of bearings is mounted on shaft  1322  of brake  1393 . Roll output gear  1373  is engaged with roll ring gear  1370 . 
     Shaft  1322  of brake  1393  is rotatably mounted in housing  1394  using a bearing on each end of shaft  1322 . Adjustment output gear  1362  of instrument manipulator positioning system gear train  1360  is fixedly mounted on shaft  1322  so that when shaft  1331  is free to spin, adjustment output gear  1362  rotates. Adjustment output gear  1362  is driven by adjustment input gear  1361  of instrument manipulator positioning system gear train  1360 . 
     A hub  1324  of brake  1393  is mounted on shaft  1322  adjacent a body  1323  that includes an electromagnetic coil and permanent magnets. Body  1323  is affixed to drive housing  1394 . An armature  1325  is connected to hub  1324  by leaf springs. When the electromagnetic coil in body  1323  is not energized, armature  1325  is affixed to body  1323  by the magnetic lines of flux of permanent magnets in body  1323 . Thus, in this state, shaft  1322  is connected to housing  1394 , e.g., shaft  1322  is connected to ground. Thus, shaft  1322  cannot spin and so adjustment output gear  1362  of instrument manipulator positioning system gear train  1360  is held in position and cannot rotate. When power is applied to the electromagnetic coil in body  1323 , a magnetic field is generated that cancels the magnetic field of the permanent magnets in body  1323 , and leaf springs connecting hub  1324  and armature  1325  pull armature  1325  upward and separate armature  1325  from body  1323 . Thus, shaft  1322  is free to spin, i.e., brake  1393  is released. 
     Roll output gear  1373  of roll system gear train  1371  drives roll ring gear  1370 . Adjustment output gear  1362  of instrument manipulator positioning system gear train  1360  drives adjustment ring gear  1341 . One end of brake shaft  1322  is coupled to a second digital potentiometer  1351  that is mounted on drive housing  1394 . Digital potentiometer  1351  measures the absolute position of adjustment ring gear  1341  with respect to the mechanical ground. 
     Thus, first digital potentiometer  1350  ( FIG. 13B ) measures the absolute position of roll ring gear  1370  with respect to the mechanical ground, while second digital potentiometer  1351  measures the absolute position of adjustment ring gear  1341  with respect to the same mechanical ground. In the roll mode (see Table 1) when roll ring gear  1370  and adjustment ring gear  1341  rotate synchronously, first digital potentiometer  1350  and second digital potentiometer  1351  both turn. In the adjustment mode, adjustment ring gear  1341  is braked and so second digital potentiometer  1351  does not turn. However, first digital potentiometer  1350  does turn and is incremented. The configuration of the surgical device assemblies is determined by the difference between first digital potentiometer and second digital potentiometer in the adjustment mode, i.e., by the relative position of roll ring gear  1370  to adjustment ring gear  1341 . 
     As described above, patient side support system  210 E is used for a variety of surgical procedures that use various combinations of instruments. Also as described above, the instruments in one aspect are grouped into sets of instruments based on the shaft characteristics of the instruments, e.g., standard surgical instrument, advanced surgical instruments, and camera instruments. Also, in some surgeries, a manual instrument or instruments may be used in conjunction with the teleoperated surgical instruments. 
     In one aspect, each standard surgical instrument has a shaft with a specified outer diameter, e.g., a 6 mm (0.237 in) outer diameter. The outer diameter of the shaft of an advanced surgical instrument is larger than the outer diameter of the shaft of the standard surgical instrument. In one aspect, advanced surgical instruments have shafts with outer diameters of 8 mm (0.315 in) and 12 mm (0.473 in). Examples of advanced surgical instruments include a stapler and a vessel sealer. 
     System  210 E has the flexibility to accommodate a specific combination of these instruments for a particular procedure, as well as a camera instrument. In one aspect, a number of different entry guides are used in system  210 E. Each different entry guide includes a different configuration of channels, as described more completely below. The channels include standard instrument channels, advanced instrument channels, camera channels, and manual channels in one aspect. In another aspect, manual channels are not included and can be eliminated or replaced with a standard instrument channel or an advanced instrument channel. The standard instrument channels are sometimes referred to as standard surgical instrument channels. The advanced instrument channels are sometimes referred to as advanced surgical instrument channels. 
     The selection of entry guides and cannula sizes for system  210 E was based on clinical needs, system feasibility, logistics, and manufacturability. The instrument channels in the entry guides were sized to include a sheath mounted on the surgical instrument. The sheath prevents tissue or entry guide features from catching on the instrument joints. 
     In one aspect, the minimum spacing between channels in an entry guide was selected to provide a minimum webbing thickness based on manufacturability, e.g., a minimum thickness between adjacent channels of 0.046 inches (1.17 mm). Similarly, the minimum outer wall thickness of the entry guide was selected based on manufacturability, e.g., a minimum outer wall thickness of 0.035 inches (0.89 mm). The diameter of the entry guide channel for manual instruments was made as large as possible while maintaining the minimum outer wall thickness and minimum thickness between adjacent channels. 
       FIGS. 14A to 14J  are illustrations of cross-sections of a family of entry guides that can be used with system  210 E. The inclusion of ten entry guides in the family is illustrative only and is not intended to be limiting. The number of entry guides in the family depends, for example, on the number of different types of surgical instruments used in a surgical procedure and the number of surgical procedures that require different shaped entry guides and/or different types and numbers of surgical instruments. In one aspect, each entry guide in the family includes the characteristics just described. The family of entry guides can be grouped into kits of two or more entry guides. Each entry guide includes a plurality of channels. A channel is defined by an interior wall or by interior walls of the entry guide. 
     As indicated above, each entry guide is inserted in a cannula. Each cannula has a common wall thickness. The wall of the cannula is made as thin as possible to minimize incision size, but thick enough to support the working loads. In addition, the thickness of the wall is large enough that the distal end of the cannula does not have a knife edge. The entry guides were selected to minimize the number of different sized cannulas required. For entry guides with a circular cross section, two cannula sizes were selected, e.g., cannulas with an inner diameter of about 25 mm (0.986 in) and about 31 mm (1.222 in). For entry guides with a non-circular cross section, the smallest circular cannula size is reported that permits that non-circular entry guide to roll about the longitudinal axis of entry guide manipulator  230  assuming that roll is allowed. However, typically non-circular entry guides and cannulas do not roll. 
     Hence, the ten entry guides presented in  FIGS. 14A to 14J  require at a minimum three cannula sizes. A standard 25 mm inner diameter cannula is used with standard entry guide  701 . A 31 mm inner diameter cannula is used with the other circular cross section entry guides. Both the 25 mm cannula and the 31 mm cannula have two sizes—a short length and a long length—for accommodating different patient anatomies. The non-circular cross section cannulas would require a cannula with a 36 mm (1.420 in) inner diameter if roll was possible in the procedure. A non-circular entry guide placed between ribs typically would not be rolled. 
     The positions of instrument channels in the various non-circular cross section entry guides were adjusted (inward) from hugging the outer perimeter of the entry guide to fit within limitations of the instrument manipulator positioning system, as described more completely below. Four unique non-circular cross section entry guides are included in the family of entry guides, one in a horizontal configuration for transoral surgery, one in a cross arm configuration for transoral surgery, and two in a vertical configuration for intercostal surgery. 
     Entry guide  1401  ( FIG. 14A ) is referred to as a standard entry guide and is the same as entry guide  571 S. Entry guide  1401  has a circular cross section. Entry guide  1401  includes four channels. The four channels are a camera channel  1401 C and three standard surgical instrument channels  1401 S 1 ,  1401 S 2 ,  1401 S 3 . Camera channel  1401 C has an oblong cross section. Herein, an oblong channel refers to a channel having an oblong cross section. Standard surgical instrument channels  1401 S 1 ,  1401 S 2 ,  1401 S 3  have a circular cross section. Herein, a circular channel refers to a channel having a circular cross section. In this aspect, each of the three circular standard surgical instrument channels  1401 S 1 ,  1401 S 2 ,  1401 S 3  is the same size, i.e., has the same diameter, e.g., 0.310 inches (7.9 mm). 
     Entry guide  1402  ( FIG. 14B ) is a first example of an advanced instrument entry guide. Entry guide  1402  has a circular cross section. Entry guide  1402  includes four channels. The four channels are an oblong camera channel  1402 C, a first circular advanced surgical instrument channel  1402 A 1 , a circular standard surgical instrument channels  1402 S 2 , and a second circular advanced surgical instrument channel  1402 A 3 . In this aspect, first and second circular advanced instrument channels  1402 A 1 ,  1402 A 3  have a same diameter, e.g., 0.428 inches (10.9 mm). 
     Entry guide  1403  ( FIG. 14C ) is a second example of an advanced instrument entry guide. Entry guide  1403  has a circular cross section. Entry guide  1403  includes four channels. The four channels are an oblong camera channel  1403 C, a first circular standard instrument channel  1403 S 1 , a circular advanced surgical instrument channel  1403 A 2 , and a second circular standard surgical instrument channels  1403 S 3 . In this aspect, first and second circular standard surgical instrument channels  1403 S 1 ,  1403 S 3  have a same diameter, e.g., 0.310 inches (7.9 mm). In one aspect, circular advanced surgical instrument channel  1403 A 2  is sized for a stapler, and has, for example, a diameter of 0.595 inches (15.1 mm). 
     Entry guide  1404  ( FIG. 14D ) is a first example of a manual port entry guide. Entry guide  1404  has a circular cross section. Entry guide  1404  includes four channels. The four channels are an oblong camera channel  1404 C, a first circular standard instrument channel  1404 S 1 , a circular manual channel  1404 M, and a second circular standard surgical instrument channels  1404 S 3 . In this aspect, first and second circular standard surgical instrument channels  1404 S 1 ,  1404 S 3  have a same diameter, e.g., 0.310 inches (7.9 mm). In one aspect, circular manual channel  1404 M has a diameter of 0.671 inches (17 mm). 
     Entry guide  1405  ( FIG. 14E ) is a second example of a manual port entry guide. Entry guide  1405  has a circular cross section. Entry guide  1405  includes four channels. The four channels are an oblong camera channel  1405 C, a first circular advanced instrument channel  1405 A 1 , a circular manual channel  1405 M, and a second circular advanced surgical instrument channels  1405 A 3 . In this aspect, first and second circular advanced surgical instrument channels  1405 A 1 ,  1405 A 3  have a same diameter, e.g., 0.428 inches (10.9 mm). In one aspect, circular manual channel  1405 M has a diameter of 0.472 inches (12 mm). 
     Entry guide  1406  ( FIG. 14F ) is a third example of a manual port entry guide. Entry guide  1406  has a circular cross section. Entry guide  1406  includes five channels. The five channels are an oblong camera channel  1406 C, three circular standard instrument channels  1406 S 1 ,  1406 S 2 ,  1406 S 3 , and a circular manual channel  1406 M. In this aspect, each of the three circular standard surgical instrument channels  1406 S 1 ,  1406 S 2 ,  1405 S 3  is the same size, i.e., has the same diameter, e.g., 0.310 inches (7.9 mm). In one aspect, circular manual channel  1406 M has a diameter of 0.505 inches (12.8 mm). 
     Entry guide  1407  ( FIG. 14G ) is a first example of a transoral entry guide, i.e., entry guide  1407  is used in minimally invasive transoral surgery. Entry guide  1407  can also be used in minimally invasive thoracic surgery. Entry guide  1407  has a non-circular cross section, e.g., an oblong cross section. The oblong cross section of entry guide  1407  has a major axis  1490  and a minor axis  1491 . Major axis  1490  is perpendicular to minor axis  1491 . Entry guide  1407  includes three channels. The three channels are an oblong camera channel  1407 C and two circular standard instrument channels  1407 S 1 ,  1407 S 3 . In this aspect, first and second circular standard surgical instrument channels  1407 S 1 ,  1407 S 3  have a same diameter, e.g., 0.310 inches (7.9 mm). First circular standard surgical instrument channel  1407 S 1  has a lengthwise axis  1481 . The oblong cross section of camera channel  1407 C has a major axis  1482 , and second circular standard surgical instrument channel  1407 S 2  has a lengthwise  1483 . Major axis  1482  is coincident with major axis  1490  of the oblong cross section of entry guide  1407 . Lengthwise axis  1481  and lengthwise axis  1483  intersect major axis  1490 . First and second circular standard surgical instrument channels  1407 S 1 ,  1407 S 3  have mirror symmetry about a minor axis  1491  of the oblong cross section of entry guide  1407 . 
     Entry guide  1408  ( FIG. 14H ) is a second example of a transoral entry guide. Entry guide  1408  has a modified triangle cross section. The cross section is a non-circular cross section and is referred to as a modified triangle cross section because the vertices of the triangle shape are rounded and one side of the triangle has a small arc in the center. Entry guide  1408  includes four channels. The four channels are an oblong camera channel  1408 C and three circular standard instrument channels  1408 S 1 ,  1408 S 2 ,  1408 S 3 . In this aspect, the three circular standard surgical instrument channels  1408 S 1 ,  1408 S 2 ,  1408 S 3  have a same diameter, e.g., 0.310 inches (7.9 mm). 
     First circular standard surgical instrument channel  1408 S 1  has a lengthwise axis  1485 . The oblong cross section of camera channel  1408 C has a major axis  1486  and a minor axis  1487 . Third circular standard surgical instrument channel  1408 S 3  has a lengthwise axis  1488 . Second circular standard surgical instrument channel  1408 S 2  has a lengthwise axis  1489 . 
     Lengthwise axes  1485 ,  1488  intersect a line  1490  that includes major axis  1486 . Line  1490  is referred to as a major axis  1490  of a cross section of entry guide  1408 . Lengthwise axis  1489  intersects a straight line  1491  that includes minor axis  1487 . Line  1491  is referred to as a minor axis  1490  of a cross section of entry guide  1408 . Major axis  1490  and minor axis  1491  intersect at length wise axis of oblong camera channel  1408 C. Entry guide  1408  has mirror symmetry about minor axis  1491 . 
     Entry guide  1409  ( FIG. 14I ) is a first example of a thoracic entry guide. Entry guide  1409  has a non-circular cross section that is a cross section with two parallel sides connected by two arcs, e.g., an oblong-like cross section. Entry guide  1409  includes three channels. The three channels are an oblong camera channel  1409 C and two circular standard instrument channels  1409 S 1 ,  1409 S 3 . In this aspect, the two circular standard surgical instrument channels  1409 S 1 ,  1409 S 3  have a same diameter, e.g., 0.310 inches (7.9 mm). 
     Entry guide  1410  ( FIG. 14J ) is a second example of a thoracic entry guide. Entry guide  1410  has a non-circular cross section that is an oblong-like cross section. Entry guide  1410  includes three channels. The three channels are an oblong camera channel  1410 C and two circular advanced surgical instrument channels  1410 A 1 ,  1410 A 3 . In this aspect, the two circular advanced surgical instrument channels  1410 A 1 ,  1410 A 3  have a same diameter, e.g., 0.428 inches (10.9 mm). 
     Table 2 is a summary of the information presented above for entry guides  1401  to  1410 . The sizes presented are illustrative only and are not intended to limit the entry guides to the specific dimensions presented. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                   
                 Entry Guide 
                   
                   
               
               
                   
                 OD or 
               
               
                 Entry Guide Configurations 
                 Maximum 
                 Manual 
                 Cannula 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Channel 
                 Dimension 
                 Lumen 
                 Main 
                 2 nd  axis 
               
               
                 Name 
                 Descriptions 
                 (mm) 
                 (mm) 
                 (mm) 
                 (mm) 
               
               
                   
               
               
                 Standard 1401 
                 Camera, 
                 25.0 
                 — 
                 26.4 
                 — 
               
               
                   
                 Standard 
               
               
                 Four Lumen: 
                 Camera, 
                 31.0 
                 — 
                 32.4 
                 — 
               
               
                 Advanced Vessel 
                 Vessel 
               
               
                 Sealer 1402 
                 Sealer 
               
               
                   
                 Standard 
               
               
                 Four Lumen: 
                 Camera 
                 31.0 
                 — 
                 32.4 
                 — 
               
               
                 Advanced Vessel 
                 Stapler 
               
               
                 Sealer 1403 
                 Standard 
               
               
                 Four Lumen: 
                 Camera 
                 31.0 
                 17.0 
                 32.4 
                 — 
               
               
                 Manual 1404 
                 Manual 
               
               
                   
                 Standard 
               
               
                 Four Lumen: 
                 Camera, 
                 31.0 
                 12.0 
                 32.4 
                 — 
               
               
                 Vessel Sealer 
                 Vessel 
               
               
                 with 
                 Sealer 
               
               
                 Manual 1405 
                 Manual 
               
               
                 Five Lumen: 
                 Camera 
                 31.0 
                  12.8. 
                 32.4 
                 — 
               
               
                 Manual 1406 
                 Manual 
               
               
                   
                 Standard 
               
               
                 Three Lumen: 
                 Camera 
                 35.4 
                 — 
                 36.8 
                 14 
               
               
                 Horizontal 1407 
                 Standard 
               
               
                 Four Lumen: 
                 Camera 
                 35.4 
                   
                 36.8 
                 23.0 
               
               
                 Horizontal: 1408 
                 Standard 
               
               
                 Three Lumen: 
                 Camera 
                 32.5 
                 — 
                 33.9 
                 19.7 
               
               
                 Vertical 1409 
                 Standard 
               
               
                 Three Lumen: 
                 Camera 
                 36.0 
                 — 
                 37.4 
                 19.7 
               
               
                 Vertical 
                 Vessel 
               
               
                 Vessel 
                 Sealer 
               
               
                 Sealer 1410 
               
               
                   
               
            
           
         
       
     
     The ten entry guide configurations with the three cannulas were analyzed to determine the range of motion required and the trajectory to be implemented in each of the four gearboxes.  FIG. 15  is a process flow diagram of a method used to perform the analysis. 
     In SELECT FAMILY OF ENTRY GUIDES  1501 , a family of entry guides is selected. This process is equivalent to the considerations described above with respect to  FIGS. 14A to 14J , and so is not repeated here. In general terms, the selection of entry guides in the family and the cannula sizes was based on clinical needs, system feasibility, logistics, and manufacturability. The clinical needs included the surgical instruments needed for the various surgical procedures that can be carried out by the minimally invasive surgical system. In the above examples, the family includes entry guides for standard surgical instruments, advanced surgical instruments, manual surgical instruments, camera instruments, and combinations of these instruments. In addition, the entry guides are selected to facilitate using as few different cannula sizes as possible in one aspect. The entry guide channel configurations are laid out according to logistics in use of the surgical instruments and manufacturability of the entry guides. 
     After a family of entry guides has been selected, MODEL FIXED ENTRY GUIDE PARAMETERS process  1502  process is performed. Some of the entry guide parameters can be directly derived from the shape and size of the entry guide, without consideration of the instrument manipulator positioning system or the surgical device assembly. For example, a camera instrument channel is always centered on the Y-axis and the center of the camera instrument channel is positioned as far as possible from the longitudinal axis of the entry guide. This provides the most room for the other surgical instrument channels and manual instrument channel(s), and results in an intuitive arrangement of the surgical instruments relative to the camera for the surgeon. Similarly, the channels for the shafts of the first and third surgical device assemblies are typically positioned symmetrically about the camera channel, at the perimeter of the entry guide, and as close as possible to the camera channel. This provides the most room for the manual channel and more flexibility for placing the channel for the shaft of another surgical device assembly mounted on the base assembly. 
     Upon completion of MODEL FIXED ENTRY GUIDE PARAMETERS process  1502 , stress regions are drawn around each instrument lumen position showing the allowable offset between the actual and ideal (minimum stress) instrument positions in STRESS REGION process  1503 . The boundary of each stress region is a line of isostress. Any point interior to the boundary has less stress than the stress on the isostress boundary. 
     Thus, minimum stress positions are first determined. In one aspect, the minimum stress position is chosen as the location where the bend in the shaft is a circular bend. With one end of the shaft fixed in place and another part of the shaft having approximately two point contact with the entry guide, the shaft follows a circular arc. The stress is being applied by a pure moment. This circular bending was taken as minimizing the stress in the shaft over the bending length, e.g. over a six inch (152.2 mm) length. In Table 3, the ideal positions for the positioning elements and hence the surgical instrument shafts are given as (x, y) coordinates. The direction of x and y is defined at the location of each positioning element in the base assembly. The values of the (x, y) coordinates (in inches) in Table 3 provide the nominal location for each instrument insertion assembly.  FIG. 16A  is  FIG. 5A  redrawn with the (x, y) coordinate systems added. As is known to those of skill in the art, the coordinates in Table 3 can be converted to millimeters by multiplying each coordinate by 25.4. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                   
                 Positioning 
                 Positioning 
                 Positioning 
                 Positioning 
               
               
                   
                 Element in Base 
                 Element in Base 
                 Element in Base 
                 Element in Base 
               
               
                 Entry Guide 
                 Assembly 432_0 
                 Assembly 432_1 
                 Assembly 432_2 
                 Assembly 432_3 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Ref. No. 
                 X 
                 Y 
                 X 
                 Y 
                 X 
                 Y 
                 X 
                 Y 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 1401 
                 0.000 
                 0.245 
                 0.288 
                 −0.094 
                 0.000 
                 −0.303 
                 −0.288 
                 0.094 
               
               
                 1402 
                 0.000 
                 0.363 
                 0.361 
                 0.000 
                 0.000 
                 −0.353 
                 −0.361 
                 0.000 
               
               
                 1403 
                 0.000 
                 0.363 
                 0.406 
                 0.110 
                 0.000 
                 −0.250 
                 −0.406 
                 −0.110 
               
               
                 1404 
                 0.000 
                 0.363 
                 0.406 
                 0.110 
                 — 
                 — 
                 −0.406 
                 −0.110 
               
               
                 1405 
                 0.000 
                 0.363 
                 0.361 
                 0.000 
                 — 
                 — 
                 −0.361 
                 0.000 
               
               
                 1406 
                 0.000 
                 0.363 
                 0.420 
                 0.110 
                 −0.286  
                 −0.308 
                 −0.420 
                 −0.110 
               
               
                 1407 
                 0.000 
                 0.000 
                 0.506 
                 0.000 
                 0.000 
                 −0.414 
                 −0.506 
                 0.000 
               
               
                 1408 
                 0.000 
                 0.000 
                 0.506 
                 0.000 
                 0.000 
                 −0.414 
                 −0.506 
                 0.000 
               
               
                 1409 
                 0.000 
                 0.393 
                 0.156 
                 0.000 
                 0.000 
                 −0.451 
                 −0.156 
                 0.000 
               
               
                 1410 
                 0.000 
                 0.461 
                 0.111 
                 0.000 
                 0.000 
                 −0.453 
                 −0.111 
                 0.000 
               
               
                   
               
            
           
         
       
     
     Transoral and thoracic entry guides  1407  to  1410  only use two of the three instrument manipulators, but positions are specified for positioning elements in all three base assemblies. This is done to avoid collisions and to provide a gap for a sterile drape. Typically, when only two manipulator assemblies and associated surgical instruments are used with an entry guide, base assembly  432 _ 1  and base assembly  432 _ 2  are used to position the two manipulator assemblies. 
     To facilitate placing the channels in the entry guide closer together to minimize the cannula diameter, the shafts of the surgical instruments are angled from the instrument housings (See  FIG. 4B ) and bent against the entry guide as they pass through the cannula. This makes up for space lost to the shaft bearings and lost to the wall thickness of the instrument housing.  FIG. 16B  illustrates a surgical instrument  1660  with a shaft  1667  that is entering an entry guide  1670  mounted in a cannula. Shaft  1667  is bent against entry guide  1670 . Surgical instrument  460  is an example of surgical instrument  1660 .  FIG. 16C  is a schematic top view of three surgical instruments  1660 _ 1 ,  1660 _ 2 ,  1660 _ 3  mounted as illustrated in  FIGS. 3A and 3B  for surgical instruments  260 _ 1 ,  260 _ 2 ,  260 _ 3 . 
     With one end of shaft  1667  fixed at the instrument housing and another point on shaft  1667  having approximately two point contact with a wall of the channel in entry guide  1670  ( FIG. 16B ), shaft  1667  follows a circular arc as depicted in  FIG. 16B . The amount of bending or angle θ needed is a function of a distance L of the bottom of the instrument housing to the top of entry guide  1670 , and the relative distances of the channel from adjacent instrument housing and lumens. Angle θ is the shaft exit angle from the housing. Distance δ is distance from a center of shaft  1667  to an outer diameter of a bearing B ( FIG. 16C ) mounted at the proximal end of shaft  1667 . Distance h is a housing theoretical sharp dimension that is used to show the derived location of the instrument housing relative to the channel. Distance G is a minimum distance that is maintained between adjacent instrument housings. 
     The circular bending assumptions minimize the stress in the shaft over the bending length assuming the worst-case insertion depth L. However, other bending can be achieved as needed to provide additional offset between the instrument housing and the entry guide lumen. This S-bending increases the shaft stress as a function of its magnitude and direction (either perpendicular or in-line to the circular bend). As used herein, an S-shaped bend, e.g., S-bending, is created when a moment and a force are applied simultaneously to the shaft. To understand how much S-bending can be tolerated, for a given shaft material, a region bounded by an isostress boundary is plotted around the ideal instrument location. The positioning element can be offset as needed to insert the shaft into the channel so long as the stress on the shaft remains on or within the isostress boundary. If the positioning element is moved from the ideal position, extra shaft bending is imposed on the instrument shaft, but the stresses associated with the extra shaft bending are within acceptable stress levels so long as the position of the positioning element, and hence the instrument shaft, remains within the isostress boundary. 
     In one aspect, the shaft material for the standard surgical instruments was stainless steel, e.g., a precipitation hardened stainless steel such as 17-4 or 17-7 stainless steel condition H 1050 . However, for the advanced surgical instruments, a different material is used. To tolerate the increased bend angle on a larger shaft, it is necessary to select a different material for the shafts of the vessel sealer and stapler instruments. 
     The advanced surgical instruments have high strength plastic shafts to allow for bending through the cannulas. In one aspect, the shafts are made from a polyether ether ketone (PEEK) plastic. PEEK plastic is an organic polymer thermoplastic. In one aspect, a PEEK plastic with a flexural modulus of 11.8 GPa (1,711 ksi) is selected for the shafts of the advanced surgical instruments. The tensile fatigue of this PEEK plastic at 10 7  cycles is a tensile strength of about 14,500 psi. A PEEK plastic having these characteristics is manufactured by Victrex® Manufacturing Limited as PEEK 450GL30. (VICTREX is a registered trademark of Victrex Manufacturing Limited of Lancashire FY5 4QD, United Kingdom.) Alternative grades of PEEK with higher stiffness are available. The alternative grades of PEEK have a modulus of elasticity of 45 GPa and 22 GPa. These grades might be required for some advanced surgical instruments to prevent shaft buckling under high cable tension. 
     In  FIG. 17 , stress regions, sometimes called stress profiles, bounded by lines of isostress, i.e., bounded by isostress boundaries are presented for each positioning element and the associated entry guide channel showing the allowable offsets from ideal (minimum stress) instrument shaft positions. Each region has a shape that is roughly a cross section of an American football shape, i.e., a cross section of an oblate spheroid shape. The stress on the shaft of an instrument is acceptable if the shaft is positioned at a location within the isostress boundary. Thus, the stress regions in  FIG. 17  are regions of acceptable stress associated with bending of a shaft of an instrument. The reference numeral for each stress profile points at the ideal position based on the information in Table 3, which is at the center of the stress profile. A first portion of the reference numeral is the reference numeral of corresponding channel in  FIGS. 14A to 14J  and this is followed with a _P to indicate that the reference numeral refers to a position. For example,  1408 S 0 _P is the ideal position for the camera instrument shaft when inserted in channel  1408 S 0  in entry guide  1408 . 
       FIG. 17  shows that the ideal locations of the camera instrument shaft with respect to channels  1401 S 0 _P to  1410 S 0 _P fall on a straight line, which is the positive portion of the y-axis of the entry guide manipulator coordinate system. An isostress boundary is not determined for the camera instrument shaft, because as described above, the camera instrument is pre-bent and so the shaft is not subjected to bending as in passes through an entry guide. 
     The stress profiles for the instrument shafts controlled by the positioning element associated with base assembly  432 _ 1  are primarily along the x-axis to the right of the y-axis, e.g., the stress profiles having centers  1401 S 1 _P to  1410 S 1 _P as illustrated in  FIG. 17 . In  FIG. 17 , the stress profiles for the instrument shafts controlled by the positioning element associated with base assembly  432 _ 2  are below the x-axis, e.g., the stress profiles having centers  1401 S 2 _P to  1410 S 3 _P,  1406 S 2 _P, and  1408 S 2 _P to  1410 S 2 _P, in this aspect. 
     The stress profiles for the instrument shafts controlled by the positioning element associated with base assembly  432 _ 3  are not presented in  FIG. 17 . The reason is that for each (x, y) value defining a boundary of a stress profile the instrument shafts controlled by the positioning element associated with base assembly  432 _ 1 , the corresponding value on a boundary of a stress profile of an the instrument shaft controlled by the positioning element associated with base assembly  432 _ 3  is (−x, −y). Therefore, when a first trajectory is determined for the positioning element associated with base assembly  432 _ 1 , a second trajectory for the positioning element associated with base assembly  432 _ 3  is the negative of the first trajectory. Accordingly, analysis of the stress data associated with positions  1401 S 1 _P to  1410 S 1 _P is sufficient to determine the same information of the positioning element associated with base assembly  432 _ 3 . 
     The stress regions generated in STRESS REGION process  1503  are used in SELECT POSITIONS process  1504 . Initially in process  1504 , a decision needs to be made on whether to use a linear trajectory gearbox ( FIGS. 10C, 10D ) or a circular trajectory gearbox ( FIGS. 10A, 10B ). 
     Thus, the endpoints of a preliminary trajectory are defined to limit the overall range of motion required. For the positioning element associated with the camera instrument, the range of motion is from position  1701  to  1702  in the (x, y) coordinate system. For the positioning element associated with the first surgical instrument that is coupled to the floating platform in base assembly  432 _ 1 , the range of motion is from position  1703  to  1704  in the (x, y) coordinate system. Finally, the positioning element associated with the second surgical instrument coupled to the floating platform in base assembly  432 _ 2 , the range of motion is from position  1705  to  1706  in the (x, y) coordinate system. 
     After the ranges of motion are defined, the trajectories and the positions that make up the trajectories are selected. For the camera instrument, a linear trajectory is required. Thus, a linear trajectory gearbox is selected for the camera instrument. For the first surgical instrument, the stress profiles in  FIG. 17  show that a straight line drawn between point  1703  and  1704  intersects all the stress profiles. Therefore, the stress on the first surgical instrument shaft is within a stress profile for each of the channels for points along the x-axis between points  1703  and  1704 . Thus, a linear trajectory gearbox is selected for the first and third surgical instruments. 
     For the second surgical instrument, a straight line between points  1705  and  1706  does not intersect all of the stress profiles and so a linear trajectory is not acceptable. To determine the circular trajectory, an iterative process is used to find a constant radius arc that includes points  1705  and  1706  and that intersects all the stress profiles. Constant radius arc  1710  that includes points  1705  and  1706  and intersects all the stress profiles is selected as the trajectory for the second surgical instrument. 
     Next, a set of positions are created on each trajectory for the positioning element. Each selected position is on a boundary or within a stress profile. While the selected positions assure that the stress on the instrument shaft is acceptable, there is the possibility that when adjacent instruments are moved to the selected positions, the instrument housings collide. Thus, the relationships of the instruments housings at the selected positions are analyzed to assure that the positions do not result in any collisions. 
     At each actual position, corresponding instrument housing is drawn based on the layout of  FIG. 16C . To avoid over defining the problem, a subset of entry guides in the family of entry guides is empirically selected. Adjacent surgical instrument housings for each entry guide configuration are paired, and the gap between the housing is measured. If there is a collision, the gap between the housings is set at predetermined gap G, e.g., 0.100 inches (2.54 mm) and the selected positions are adjusted to obtain this spacing. If there is not a collision, the gap between the instrument housing is saved for a final verification of the trajectories. This process is repeated for each entry guide in the subset of entry guides. The predetermined gap is also used to define the offsets for the camera-positioning element. For the positions that are not limited by the clearance with an adjacent instrument housing, positions are selected according to convenient properties, such as being evenly spaced along the trajectory or where instrument shaft stress is minimized. 
     The square boxes along the x-axis in  FIG. 17  represent the positions on the linear trajectory of the first surgical instrument. The positions for a linear trajectory are not as critical because, as described above, the positioning element is not constrained to moving in a single direction. In one aspect, the linear trajectory uses some of the points more than once as the trajectory moves back and forth along the trajectory based on the design of the linear gearbox. The square boxes along arc  1710  in  FIG. 17  represent the positions on the circular trajectory of the second surgical instrument. 
       FIG. 18A  illustrates the surgical instrument and camera instrument trajectories and ranges of motion of the output pins of gearboxes  1842 _ 0 ,  1842 _ 1 ,  1842 _ 2  for the family of entry guides in  FIGS. 14A to 14J . The plot is oriented looking down the cannula, with each gearbox position labeled. The trajectory of the output pin of gearbox  1842 _ 3  (not shown) is not drawn because it is taken as the negative of the trajectory and range of motion of gearbox  1842 _ 1 . As shown, the trajectory of the output pin of gearbox  1842 _ 3  is circular and the other trajectories of the other three gearboxes are linear. Table 4 give values associated with the reference numbers in  FIG. 18  for entry guides  1401  to  1410 . 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                 Reference No. 
                 Dimension (inches) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 1801 
                 0.461 
                 (11.69 mm) 
               
               
                   
                 1802 
                 0.245 
                 (6.21 mm) 
               
               
                   
                 1803 
                 0.208 
                 (5.07 mm) 
               
               
                   
                 1804 
                 0.454 
                 (11.51 mm) 
               
               
                   
                 1805 
                 0.250 
                 (6.34 mm) 
               
               
                   
                 1806 
                 0.454 
                 (11.51 mm) 
               
               
                   
                 1807 
                 0.040 
                 (1.01 mm) 
               
               
                   
                 1808 
                 0.177 
                 (4.49 mm) 
               
               
                   
                   
               
            
           
         
       
     
     To reduce the range of motion of the camera instrument, in one aspect, two camera instruments are used in the surgical system, e.g., surgical system  200 C. The first camera instrument is used with all entry guides except entry guides  1407  and  1408 . The second camera instrument is used only for entry guides  1407  and  1408 . The difference between the two cameras is the location of the shaft bend.  FIGS. 19A and 19B  are schematic illustrations of camera instruments  1960 A and  1960 B. Camera instrument  260 _ 0  is an example of either camera instrument  1960 A or camera instrument  1960 B. 
     Lines  1900 A and  1900 B represent planes  1900 A and  1900 B, respectively that are perpendicular to the page. Plane  1900 A bisects a first pair of drive disks of camera instrument  1960 A that provide motion to the distal articulating joints of camera instrument  1960 A. The location of the start of the bend in shaft  1967 A is defined by the distance from the start of the bend in the shaft to plane  1900 A. For the first camera instrument, the distance is X1, e.g., 1.739 inches (44.10 mm). Plane  1900 B bisects a first pair of drive disks of camera instrument  1960 B that provide motion to the distal articulating joints of camera instrument  1960 B. For the second camera instrument, the distance is X2, e.g., 1.833 inches (46.48 mm). 
     The use of the two camera instruments reduces the range of motion required by the linear gearbox associated with the camera instrument to the range presented in  FIG. 18  instead of the range of motion of 0.0 to 0.461 inches (0.0 to 11.69 mm) shown in  FIG. 17 . In another aspect, only a single camera instrument is used. 
     The range of motion of the gearboxes for the three surgical instruments is 0.246 inches (6.24 mm) in the radial direction and 0.217 inches (5.50 mm) in the lateral direction. The camera gearbox has a range of motion of 0.216 inches (5.48 mm) in the radial direction. Hence, the combined ranges of motion required by all the instruments are 0.246 inches (6.24 mm) in the radial direction and 0.217 inches (5.50 mm) in the lateral direction. 
     The order of the entry guides as moved by the positioning system in entry guide manipulator is defined by circular gearbox positions for the second surgical instrument. In Table 5, the relative positions are specified as a function of the output gear angle in the circular gearbox. 
     
       
         
           
               
               
             
               
                   
                 TABLE 5 
               
             
            
               
                   
                   
               
               
                   
                 Entry Guide Ref. No. 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 706 
                 703, 704 
                 701 
                 702, 705 
                 707, 708 
                 709, 710 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Output 
                 0° 
                 77° 
                 117° 
                 133.9° 
                 150.8° 
                 161° 
               
               
                 Gear 
               
               
                 Angle in 
               
               
                 Gearbox 
               
               
                   
               
            
           
         
       
     
     In the above analysis, the bending stress associated with a shaft of an instrument was determined only for the instrument designed to be inserted in a particular channel of the entry guide. For example, a standard surgical instrument with a smaller diameter shaft was not considered to be inserted in one of the larger diameter channels designed for an advanced surgical instrument. 
     However, in another aspect, it was assumed that a bushing would be inserted in a larger diameter channel so that a standard surgical instrument could be passed through the channel designed, for example, for an advanced surgical instrument. Thus, the stress analysis was repeated for a set of guide tubes where a standard surgical instrument is allowed to be used with a guide tube channel designed, for example, for an advanced surgical instrument. Also, the analysis assured that instrument collisions were not a problem. Finally, the analysis in addition to the constraints imposed by the different channel locations in the entry guides also specified a draping position for each of the instrument manipulators. In particular, the instrument manipulators were moved apart so that draping was facilitated. The result of this analysis was the second set of gearboxes that are illustrated in  FIGS. 11A to 11K . 
     The analysis of the entry guides in combination with the draping position found that each instrument manipulator, e.g., each surgical device assembly, must be moved to one of seven locations to accommodate the set of entry guides of interest. The first location is the draping location, and the other six locations are based on the combination of entry guide and surgical device assembly being used. 
       FIG. 18B  illustrates the seven locations for the instrument manipulator associated with gearbox  942 _ 0 _ 2  ( FIGS. 11A and 11B ).  FIG. 18C  illustrates the seven locations of output pin  1149 _B in slot  1144 _B ( FIG. 11B ). In  FIGS. 18B to 18I , the coordinate systems are relative to the manipulator assembly and not to any world coordinate system. TABLE 6A presents values in inches for each of the dimensions shown in  FIG. 18B . TABLE 6B presents values in inches for each of the dimensions shown in  FIG. 18C . The numbers in parentheses in TABLES 6A and 6B are in millimeters. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 6A 
               
               
                   
                   
               
             
            
               
                   
                 MX0_1 
                 0.1880 (4.77) 
                 MY0_1 
                 0.0000 (0.00) 
               
               
                   
                 MX0_2 
                 −0.0920 (−2.33) 
                 MY0_2 
                 0.0000 (0.00) 
               
               
                   
                 MX0_3 
                 0.1265 (3.21) 
                 MY0_3 
                 0.0000 (0.00) 
               
               
                   
                 MX0_4 
                 0.1265 (3.21) 
                 MY0_4 
                 0.0000 (0.00) 
               
               
                   
                 MX0_5 
                 0.0091 (0.23) 
                 MY0_5 
                 0.0000 (0.00) 
               
               
                   
                 MX0_6 
                 0.1568 (3.98) 
                 MY0_5 
                 0.0000 (0.00) 
               
               
                   
                 MX0_7 
                 0.2250 (5.71) 
                 MY0_7 
                 0.0000 (0.00) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 6B 
               
               
                   
                   
               
             
            
               
                   
                 SX0_1 
                 0.048 (1.22) 
                 SY0_1 
                  0.00 (0.00) 
               
               
                   
                 SX0_2 
                 −0.232 (−5.88) 
                 SY0_2 
                 0.000 (0.00) 
               
               
                   
                 SX0_3 
                 −0.014 (−0.36) 
                 SY0_3 
                 0.000 (0.00) 
               
               
                   
                 SX0_4 
                 −0.014 (−0.36) 
                 SY0_4 
                 0.000 (0.00) 
               
               
                   
                 SX0_5 
                 −0.131 (−3.32) 
                 SY0_5 
                 0.000 (0.00) 
               
               
                   
                 SX0_6 
                 0.017 (0.43) 
                 SY0_5 
                 0.000 (0.00) 
               
               
                   
                 SX0_7 
                 0.085 (2.16) 
                 SY0_7 
                 0.000 (0.00) 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 18D  illustrates the seven locations for the instrument manipulator associated with gearbox  942 _ 1 _ 2  ( FIGS. 11C and 11D .)  FIG. 18E  illustrates the seven locations of output pin  1149 _D in slot  1144 _D ( FIG. 11D ). TABLE 7A presents values in inches for each of the dimensions shown in  FIG. 18D . TABLE 7B presents values in inches for each of the dimensions shown in  FIG. 18E . The numbers in parentheses in TABLES 7A and 7B are in millimeters. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 7A 
               
               
                   
                   
               
             
            
               
                   
                 MX1_1 
                 0.160 (4.06) 
                 MY1_1 
                 −0.042 (−1.07) 
               
               
                   
                 MX1_2 
                 0.235 (5.96) 
                 MY1_2 
                 −0.069 (−1.75) 
               
               
                   
                 MX1_3 
                 0.160 (4.06) 
                 MY1_3 
                 −0.042 (−1.07) 
               
               
                   
                 MX1_4 
                 0.076 (1.93) 
                 MY1_4 
                 0.070 (1.78) 
               
               
                   
                 MX1_5 
                 0.076 (1.93) 
                 MY1_5 
                 0.070 (1.78) 
               
               
                   
                 MX1_6 
                 0.076 (1.93) 
                 MY1_5 
                 0.069 (1.75) 
               
               
                   
                 MX1_7 
                 0.076 (1.93) 
                 MY1_7 
                  0.069 (−1.75) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 7B 
               
               
                   
                   
               
             
            
               
                   
                 SX1_1 
                 0.010 (0.25) 
                 SY1_1 
                 −0.042 (−1.07) 
               
               
                   
                 SX1_2 
                 0.085 (2.16) 
                 SY1_2 
                 −0.069 (−1.75) 
               
               
                   
                 SX1_3 
                 0.010 (0.25) 
                 SY1_3 
                 −0.042 (−1.07) 
               
               
                   
                 SX1_4 
                 −0.074 (−1.88) 
                 SY1_4 
                 0.070 (1.78) 
               
               
                   
                 SX1_5 
                 −0.074 (−1.88) 
                 SY1_5 
                 0.070 (1.78) 
               
               
                   
                 SX1_6 
                 −0.197 (−5.00) 
                 SY1_5 
                 0.091 (2.31) 
               
               
                   
                 SX1_7 
                 −0.261 (−6.62) 
                 SY1_7 
                 0.089 (2.26) 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 18F  illustrates the seven locations for the instrument manipulator associated with gearbox  942 _ 2 _ 2  ( FIGS. 11E to 11H ).  FIG. 18G  illustrates the seven locations of output pin  1149 _G in slot  1144 _G ( FIG. 11G ). TABLE 8A presents values in inches for each of the dimensions shown in  FIG. 18F . TABLE 8B presents values in inches for each of the dimensions shown in  FIG. 18G . The numbers in parentheses in TABLES 8A and 8B are in millimeters. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 8A 
               
               
                   
                   
               
             
            
               
                   
                 MX2_1 
                 0.165 (4.18) 
                 MY2_1 
                 −0.012 (−0.30) 
               
               
                   
                 MX2_2 
                 0.014 (0.36) 
                 MY2_2 
                 0.000 (0.00) 
               
               
                   
                 MX2_3 
                 0.024 (0.61) 
                 MY2_3 
                 0.000 (0.00) 
               
               
                   
                 MX2_4 
                 0.084 (2.13) 
                 MY2_4 
                 0.000 
               
               
                   
                 MX2_5 
                 0.094 (2.38) 
                 MY2_5 
                 0.000 (0.00) 
               
               
                   
                 MX2_6 
                 0.198 (5.02) 
                 MY2_5 
                 −0.022 (−0.56) 
               
               
                   
                 MX2_7 
                 0.198 (5.02) 
                 MY2_7 
                 −0.022 (−0.56) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 8B 
               
               
                   
                   
               
             
            
               
                   
                 SX2_1 
                 0.015 (0.38) 
                 SY2_1 
                 −0.012 (−0.30) 
               
               
                   
                 SX2_2 
                 −0.136 (−3.45) 
                 SY2_2 
                 0.000 (0.00) 
               
               
                   
                 SX2_3 
                 −0.126 (−3.20) 
                 SY2_3 
                 0.042 (1.07) 
               
               
                   
                 SX2_4 
                 −0.066 (−1.67) 
                 SY2_4 
                 0.070 (1.78) 
               
               
                   
                 SX2_5 
                 −0.056 (142)   
                 SY2_5 
                 0.070 (1.78) 
               
               
                   
                 SX2_6 
                 0.048 (122)  
                 SY2_5 
                 −0.022 (−0.56) 
               
               
                   
                 SX2_7 
                 0.048 (122)  
                 SY2_7 
                 −0.022 (−0.56) 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 18H  illustrates the seven locations for the instrument manipulator associated with gearbox  942 _ 3 _ 2  ( FIGS. 11I to 11J ).  FIG. 18I  illustrates the seven locations of output pin  1149 _J in slot  1144 _J ( FIG. 11J ). TABLE 9A presents values in inches for each of the dimensions shown in  FIG. 18D . TABLE 9B presents values in inches for each of the dimensions shown in  FIG. 18E . The numbers in parenthesis in TABLES 9A and 9B are in millimeters. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 9A 
               
               
                   
                   
               
             
            
               
                   
                 MX3_1 
                 0.160 (4.06) 
                 MY3_1 
                 0.042 (1.07) 
               
               
                   
                 MX3_2 
                 0.235 (5.96) 
                 MY3_2 
                 0.069 (1.75) 
               
               
                   
                 MX3_3 
                 0.160 (4.06) 
                 MY3_3 
                 0.042 (1.07) 
               
               
                   
                 MX3_4 
                 0.076 (1.93) 
                 MY3_4 
                 −0.070 (−1.78) 
               
               
                   
                 MX3_5 
                 0.076 (1.93) 
                 MY3_5 
                 −0.070 (−1.78) 
               
               
                   
                 MX3_6 
                 −0.047 (−1.19) 
                 MY3_5 
                 −0.091 (−2.31) 
               
               
                   
                 MX3_7 
                 −0.111 (−2.81) 
                 MY3_7 
                 −0.089 (−2.26) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 9B 
               
               
                   
                   
               
             
            
               
                   
                 SX3_1 
                 0.010 (0.25) 
                 SY3_1 
                 0.042 (1.07) 
               
               
                   
                 SX3_2 
                 0.085 (2.16) 
                 SY3_2 
                  0.069 (−1.75) 
               
               
                   
                 SX3_3 
                 0.010 (0.25) 
                 SY3_3 
                 0.042 (107)  
               
               
                   
                 SX3_4 
                 −0.074 (−1.88) 
                 SY3_4 
                 −0.070 (−1.78) 
               
               
                   
                 SX3_5 
                 −0.074 (−1.88) 
                 SY3_5 
                 −0.070 (−1.78) 
               
               
                   
                 SX3_6 
                 −0.197 (−5.00) 
                 SY3_5 
                 −0.091 (−2.31) 
               
               
                   
                 SX3_7 
                 −0.261 (−6.62) 
                 SY3_7 
                 −0.089 (−2.26) 
               
               
                   
                   
               
            
           
         
       
     
     In one aspect, a control system  2000  ( FIG. 20A ) of the surgical system includes an instrument manipulator positioning system compatibility module  2010 . Control system  2000  also has compatibility and configuration data  2015  that is stored in a memory and a system management module  2025 . 
     In  FIG. 20A , control system  2000  and system management module  2025  are illustrated as elements in a single location. This is for ease of description and is not intended to be limiting. Typically, control system  2000  and the system management module  2025  are distributed throughout the surgical system and interconnected so that the various components can communicate as necessary. Also, those knowledgeable in the field understand that a module can be implemented in hardware, firmware, stored computer code that is executed on a processor, or any combination of the three. 
     In one aspect, instrument manipulator positioning system compatibility module  2010  performs method  2050  ( FIG. 20B ). Prior to considering method  2050  in further detail, it is helpful to understand some of the surgical instrument and entry guide inputs  2001 . When sterile adapter assembly  250  is mounted on manipulator assembly  240  ( FIG. 4A ) a switch is activated that sends a signal to system management module  2025  and to compatibility and configuration data  2015  indicating mounting of sterile adapter  2025 . In response to this signal, control system  2000  activates drive motors in manipulator assembly  240  to mate drive disks in manipulator assembly  240  with intermediate disks in sterile adapter  250 . 
     When surgical instrument  260  is mounted in sterile adapter assembly  250 , a second switch is activated that sends a signal to system management module  2025  and to compatibility and configuration data  2015  indicating mounting of surgical instrument  260 . In response to this signal, control system  2000  activates the drive motors in manipulator assembly  240  to mate the intermediate disks in sterile adapter assembly  250  with driven disks in driven interface assembly  461  of surgical instrument  260 . Controls system  2000  also activates the RFID reader  445  in manipulator assembly  240  to read the RFID tag  455  on surgical instrument  260 . The identification information read from RFID tag is supplied to system management module  2025  and to compatibility and configuration data  2015 . 
     Thus, as each surgical instrument is mounted on system  210 C, a signal indicating the mounting and information about the surgical instrument are provided to SYSTEM READY check process  2051 . Also, identification information of cannula  275 E and entry guide  270 E are supplied to SYSTEM READY check process  2051 . In one aspect, RFID tags on cannula  275 E and entry guide  270 E are scanned by an RFID reader connected to control system  2090  to obtain the identification information. In another aspect, a user enters the identification information of cannula  275 E and entry guide  270 E via a user interface provided by control system  2000 , e.g., a user interface on the surgeon&#39;s control console. Also, the identification information could be obtained via color, physical features such as pins on the mount paint, magnetic rings, etc. 
     If a user tries to use system  200 C prior to SYSTEM READY check process  2051  receiving the information from the surgical instruments and from the cannula and entry guide, SYSTEM READY check process  2051  activates a first warning signal  2003  to system management module  2025 . In response to first active warning signal  2003 , system management module  2025  generates a warning to the user. For example, a message is presented on display screens indicating that one or more components have not been registered with control system  2000  and that system operation is inhibited until successful registration. In addition to the visual message, an audio message or alarm may be generated. 
     When all the surgical instruments, the cannula, and the entry guide have been registered with control system  2000 , SYSTEM READY check process  2051  transfers processing to COMPATIBLE check process  2052 . COMPATIBLE check process  2052  retrieves information from stored compatibility and configuration data  2015  that is associated with the entry guide mounted in system  200 C. COMPATIBLE check process  2052  first checks that the entry guide is in the family of entry guides associated with the instrument manipulator positioning system in entry guide manipulator  230 . If the entry guide is not in the family, check process  2052  sends a second active warning signal  2003  to control system  2000  that in turn notifies the user that the entry guide is not appropriate for use in system  200 C. 
     If the entry guide is in the family, check process  2052  determines whether the mounted surgical instruments and camera instrument are compatible with the mounted entry guide, and if the surgical instruments are compatible whether the surgical instruments are mounted in the correct locations. If either of these checks is not true, check process  2052  sends a third active warning signal  2003  to control system  2000  that in turn notifies the user of the problem with the surgical instrument configuration. 
     In one aspect, check process  2052  determines whether other elements installed on system  200 C, such as, drapes, foot pedal control assemblies, master control assemblies, etc. are compatible based on the entry guide configuration and causes a warning message to be sent if an incompatibility is detected. 
     When check process  2052  determines that the various elements installed on system  200 C are compatible, processing transfers to CONFIGURE SYSTEM process  2053 . In one aspect, CONFIGURE SYSTEM process  2053  automatically activates the instrument manipulator positioning system and moves the adjustment disk to the appropriate position so that each of the instrument shafts are positioned for insertion into the entry guide. In another aspect, CONFIGURE SYSTEM process  2053  sends a first active configuration message signal  2004  to system management module  2025 . In response to signal  2004 , system management module  2025  sends a command to a display module to inform the user to manually move the adjustment disk to the correct position. 
     In one aspect, CONFIGURE SYSTEM process  2053  also retrieves configuration data from compatibility and configuration data  2015  and sends the data to system management module  2025  to configure system  200 C for operation with the entry guide. For example, system management module  2025  uses the configuration data to adjust its user interface for a specific type of surgery given the type of entry guide installed. Module  2025  can use the configuration data to adjust user interface elements, allowable control modes, type and behavior of control modes, design of visible interface elements, audible tones, and any other aspect of the user interface for either the surgeon or patient side assistant, based on the entry guide configuration. Upon completion of CONFIGURE SYSTEM process  2053 , ENABLE FULL OPERATION process  2054  sends an active enable signal  2005  to system management module  2025  to indicate that system  200 C is properly configured to perform surgery with the entry guide mounted in system  200 C. 
       FIGS. 21A and 21B  are illustrations of a side view of base assemblies  2132 _ 0  and  2132 _ 1  mounted to a portion  2130  of entry guide manipulator  230 . In one aspect, an insertion assembly with an attached surgical device assembly is connected to a floating platform in each of base assemblies  2132 _ 0  and  2132 _ 1 , but the insertion assembly with the attached surgical device assembly is not shown in  FIGS. 21A and 21B . 
     Base assembly  2132 _ 0  is connected to portion  2130  by a hinge assembly  2133 _ 0 . A plane including a longitudinal axis of hinge assembly  2133 _ 0  is perpendicular to a plane including the longitudinal axis of entry guide manipulator  230 . Similarly, base assembly  2132 _ 1  is connected to portion  2130  by a hinge assembly  2133 _ 1 . Each of the other two base assemblies that are not visible in  FIG. 21A  is similarly connected to portion  2130 . In  FIG. 21B , base assemblies  2132 _ 0  and  2132 _ 1  have been pivoted to allow access to base assemblies  2132 _ 0  and  2132 _ 1  for maintenance or other actions. Base assemblies  2132 _ 2  and  2132 _ 3  are visible in  FIG. 21B . 
       FIG. 22A  is a side view of base assemblies  2232 _ 0  and  2232 _ 1  mounted to a portion  2230  of entry guide manipulator  230 .  FIGS. 22B and 22C  are top views of base assemblies  2232 _ 0 ,  2232 _ 1 ,  2232 _ 2 , and  2232 _ 2  mounted to portion  2230 . In one aspect, an insertion assembly with an attached surgical device assembly is connected to a floating platform in each of base assemblies  2232 _ 0 ,  2232 _ 1 , and  2232 _ 2 , but the insertion assembly with the attached surgical device assembly is not shown in  FIGS. 22A to 22C . 
     Base assembly  2232 _ 0  is connected to portion  2230  by a hinge assembly  2233 _ 0 . Hinge assembly  2233 _ 0  extends distally from entry guide manipulator  230 . Similarly, base assembly  2232 _ 1  is connected to portion  2230  by a hinge assembly  2233 _ 1 . Each of the other two base assemblies  2232 _ 2 , and  2232 _ 2  is similarly connected to portion  2230  by hinge  2233 _ 2  and hinge  2233 _ 3 , respectively. In  FIG. 22C , base assembly  2232 _ 1  has been pivoted to allow access to base assembly  2232 _ 1  for maintenance or other actions. 
       FIGS. 23A and 23B  are illustrations of a side view of base assemblies  2332 _ 0  and  2332 _ 1  mounted to a portion  2330  of entry guide manipulator  230 . In one aspect, an insertion assembly with an attached surgical device assembly is connected to a floating platform in each of base assemblies  2332 _ 0  and  2332 _ 1 , but the insertion assembly with the attached surgical device assembly is not shown in  FIGS. 23A and 23B . 
     Base assembly  2332 _ 0  is connected to portion  2330  by a set of rails. Similarly, base assembly  2332 _ 1  is connected to portion  2330  by a set of rails. Each of the other two base assemblies that are not visible in  FIG. 23A  is similarly connected to portion  2330 . In  FIG. 23B , base assembly  2332 _ 1  has been slid out on set of rails  2333 _ 1  to allow access to base assembly  2332 _ 1  for maintenance or other actions. Base assembly  2332 _ 2  is visible in  FIG. 23B . 
     In some of the above examples, the terms “proximal” or “proximally” are used in a general way to describe an object or element which is closer to a manipulator arm base along a kinematic chain of system movement or farther away from a remote center of motion (or a surgical site) along the kinematic chain of system movement. Similarly, the terms “distal” or “distally” are used in a general way to describe an object or element which is farther away from the manipulator arm base along the kinematic chain of system movement or closer to the remote center of motion (or a surgical site) along the kinematic chain of system movement. 
     As used herein, “first,” “second,” “third,” “fourth,” etc. are adjectives used to distinguish between different components or elements. Thus, “first,” “second,” “third,” “fourth,” etc. are not intended to imply any ordering of the components or elements, or any particular number of different types of elements, e.g., three elements of the same type can be denoted as first, second, and third 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 spirit and 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&#39;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&#39;s or feature&#39;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. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 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.