US20230355338A1 - Articulating including antagonistic controls for articulation and calibration - Google Patents
Articulating including antagonistic controls for articulation and calibration Download PDFInfo
- Publication number
- US20230355338A1 US20230355338A1 US18/303,253 US202318303253A US2023355338A1 US 20230355338 A1 US20230355338 A1 US 20230355338A1 US 202318303253 A US202318303253 A US 202318303253A US 2023355338 A1 US2023355338 A1 US 2023355338A1
- Authority
- US
- United States
- Prior art keywords
- drive
- driver
- drive input
- articulation
- surgical tool
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003042 antagnostic effect Effects 0.000 title claims description 5
- 238000000034 method Methods 0.000 claims abstract description 44
- 239000012636 effector Substances 0.000 claims description 81
- 230000033001 locomotion Effects 0.000 claims description 55
- 230000006870 function Effects 0.000 claims description 28
- 238000013519 translation Methods 0.000 claims description 21
- 238000004891 communication Methods 0.000 claims description 18
- 238000004519 manufacturing process Methods 0.000 claims description 16
- 238000012937 correction Methods 0.000 claims description 13
- 210000003857 wrist joint Anatomy 0.000 claims description 11
- 230000006835 compression Effects 0.000 claims description 5
- 238000007906 compression Methods 0.000 claims description 5
- 230000001419 dependent effect Effects 0.000 claims description 4
- 238000012886 linear function Methods 0.000 claims description 4
- 210000000707 wrist Anatomy 0.000 description 129
- 230000000875 corresponding effect Effects 0.000 description 52
- 150000001875 compounds Chemical class 0.000 description 29
- 230000008569 process Effects 0.000 description 20
- 230000007246 mechanism Effects 0.000 description 15
- 238000010304 firing Methods 0.000 description 13
- 230000008859 change Effects 0.000 description 12
- 210000002969 egg yolk Anatomy 0.000 description 12
- 230000007935 neutral effect Effects 0.000 description 12
- 230000001276 controlling effect Effects 0.000 description 11
- 230000008878 coupling Effects 0.000 description 11
- 238000010168 coupling process Methods 0.000 description 11
- 238000005859 coupling reaction Methods 0.000 description 11
- 238000005520 cutting process Methods 0.000 description 11
- 230000000007 visual effect Effects 0.000 description 7
- 230000008901 benefit Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000012546 transfer Methods 0.000 description 6
- 238000001356 surgical procedure Methods 0.000 description 5
- 210000000683 abdominal cavity Anatomy 0.000 description 4
- 238000013459 approach Methods 0.000 description 4
- 230000001186 cumulative effect Effects 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000013011 mating Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 238000012806 monitoring device Methods 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000001839 endoscopy Methods 0.000 description 2
- 238000007620 mathematical function Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 235000004443 Ricinus communis Nutrition 0.000 description 1
- 240000000528 Ricinus communis Species 0.000 description 1
- 210000001015 abdomen Anatomy 0.000 description 1
- 210000003815 abdominal wall Anatomy 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000002594 fluoroscopy Methods 0.000 description 1
- 210000000245 forearm Anatomy 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000002357 laparoscopic surgery Methods 0.000 description 1
- 238000002595 magnetic resonance imaging Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 210000000056 organ Anatomy 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000037361 pathway Effects 0.000 description 1
- 230000002980 postoperative effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000004043 responsiveness Effects 0.000 description 1
- 238000002432 robotic surgery Methods 0.000 description 1
- 230000037390 scarring Effects 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 230000001225 therapeutic effect Effects 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
- A61B34/70—Manipulators specially adapted for use in surgery
- A61B34/71—Manipulators operated by drive cable mechanisms
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
- A61B34/30—Surgical robots
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/068—Surgical staplers, e.g. containing multiple staples or clamps
- A61B17/072—Surgical staplers, e.g. containing multiple staples or clamps for applying a row of staples in a single action, e.g. the staples being applied simultaneously
- A61B17/07207—Surgical staplers, e.g. containing multiple staples or clamps for applying a row of staples in a single action, e.g. the staples being applied simultaneously the staples being applied sequentially
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/00234—Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery
- A61B2017/00292—Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery mounted on or guided by flexible, e.g. catheter-like, means
- A61B2017/003—Steerable
- A61B2017/00305—Constructional details of the flexible means
- A61B2017/00314—Separate linked members
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/00234—Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery
- A61B2017/00292—Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery mounted on or guided by flexible, e.g. catheter-like, means
- A61B2017/003—Steerable
- A61B2017/00318—Steering mechanisms
- A61B2017/00323—Cables or rods
- A61B2017/00327—Cables or rods with actuating members moving in opposite directions
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B2017/00681—Aspects not otherwise provided for
- A61B2017/00725—Calibration or performance testing
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/068—Surgical staplers, e.g. containing multiple staples or clamps
- A61B17/072—Surgical staplers, e.g. containing multiple staples or clamps for applying a row of staples in a single action, e.g. the staples being applied simultaneously
- A61B2017/07214—Stapler heads
- A61B2017/07285—Stapler heads characterised by its cutter
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/28—Surgical forceps
- A61B17/29—Forceps for use in minimally invasive surgery
- A61B2017/2901—Details of shaft
- A61B2017/2902—Details of shaft characterized by features of the actuating rod
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/28—Surgical forceps
- A61B17/29—Forceps for use in minimally invasive surgery
- A61B2017/2901—Details of shaft
- A61B2017/2908—Multiple segments connected by articulations
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/28—Surgical forceps
- A61B17/29—Forceps for use in minimally invasive surgery
- A61B17/2909—Handles
- A61B2017/2912—Handles transmission of forces to actuating rod or piston
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/28—Surgical forceps
- A61B17/29—Forceps for use in minimally invasive surgery
- A61B17/2909—Handles
- A61B2017/2912—Handles transmission of forces to actuating rod or piston
- A61B2017/2919—Handles transmission of forces to actuating rod or piston details of linkages or pivot points
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/28—Surgical forceps
- A61B17/29—Forceps for use in minimally invasive surgery
- A61B2017/2926—Details of heads or jaws
- A61B2017/2927—Details of heads or jaws the angular position of the head being adjustable with respect to the shaft
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
- A61B34/30—Surgical robots
- A61B2034/305—Details of wrist mechanisms at distal ends of robotic arms
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
- A61B34/70—Manipulators specially adapted for use in surgery
- A61B34/71—Manipulators operated by drive cable mechanisms
- A61B2034/715—Cable tensioning mechanisms for removing slack
Abstract
A method of homing a drive input of a robotic surgical tool includes recording and storing a home position of the drive input in a memory included in the robotic surgical tool, establishing a slow zone for the drive input encompassing a known angular magnitude away from the home position, storing the slow zone in the memory, rotating the drive input toward the home position, and slowing a rotation speed of the drive input upon reaching the slow zone.
Description
- Minimally invasive surgical (MIS) instruments are often preferred over traditional open surgical devices due to the reduced post-operative recovery time and minimal scarring. The most common MIS procedure may be endoscopy, and the most common form of endoscopy is laparoscopy, in which one or more small incisions are formed in the abdomen of a patient and a trocar is inserted through the incision to form a pathway that provides access to the abdominal cavity. The trocar is used to introduce various instruments and tools into the abdominal cavity, as well as to provide insufflation to elevate the abdominal wall above the organs. The instruments can be used to engage and/or treat tissue in a number of ways to achieve a diagnostic or therapeutic effect.
- Each surgical tool typically includes an end effector arranged at its distal end. Example end effectors include clamps, graspers, scissors, staplers, and needle holders, and are similar to those used in conventional (open) surgery except that the end effector of each tool is separated from its handle by an approximately 12-inch long shaft. A camera or image capture device, such as an endoscope, is also commonly introduced into the abdominal cavity to enable the surgeon to view the surgical field and the operation of the end effectors during operation. The surgeon is able to view the procedure in real-time by means of a visual display in communication with the image capture device.
- Surgical staplers are one type of end effector capable of cutting and simultaneously stapling (fastening) transected tissue. Alternately referred to as an “endocutter,” the surgical stapler includes opposing jaws capable of opening and closing to grasp and release tissue. Once tissue is grasped or clamped between the opposing jaws, the end effector may be “fired” to advance a cutting element or knife distally to transect grasped tissue. As the cutting element advances, staples contained within the end effector are progressively deployed to seal opposing sides of the transected tissue.
- Surgical tools include articulable wrists configured to permit angling of the end effector into a desired orientation. An articulable wrist having a joint that provides a high degree of freedom is needed. Also needed is a system for powering the articulable wrist such that it may move smoothly through tissue, which provides an external load on the wrist, and maintain a position into which it has been articulated when subjected to such external load. Moreover, systems for homing the drive inputs of the surgical are needed that, upon installing the surgical tool in the robotic manipulator, reposition the articulable wrist into an unarticulated orientation such that it may be inserted through a trocar and into the abdominal cavity.
- The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure.
-
FIG. 1 is a block diagram of an example robotic surgical system that may incorporate some or all of the principles of the present disclosure. -
FIG. 2 is an example embodiment of one of the master control consoles ofFIG. 1 . -
FIG. 3 depicts one example of the robotic manipulator ofFIG. 1 , according to one or more embodiments. -
FIG. 4 is an isometric side view of an example surgical tool that may incorporate some or all of the principles of the present disclosure. -
FIG. 5 illustrates potential degrees of freedom in which the wrist ofFIG. 4 may be able to articulate (pivot). -
FIG. 6 is a bottom view of the drive housing ofFIG. 4 , according to one or more embodiments. -
FIGS. 7A and 7B are exposed isometric views of the interior of the drive housing ofFIG. 4 , according to one or more embodiments. -
FIGS. 8A and 8B are exposed isometric views depicting example gear trains within the surgical tool ofFIGS. 7A-7B . -
FIGS. 9A and 9B are exposed bottom views of the surgical tool ofFIG. 4 . -
FIG. 10A illustrates an example articulable wrist that may be utilized in the surgical tool ofFIGS. 9A and 9B , according to one or more embodiments of the disclosure. -
FIG. 10B is an exploded view of the articulable wrist ofFIG. 10A , according to one or more embodiments of the disclosure. -
FIGS. 11A-11C illustrate various example algorithms programmable into the computer system ofFIG. 6 to control operation of the drivers ofFIG. 6 , according to various embodiments of the present disclosure. -
FIG. 12 illustrates a set of graphs showing an example operation of an example homing system, according to one or more embodiments of the disclosure. -
FIG. 13 illustrates to exposed view of an exemplary joint of the wrist inFIGS. 10A-10B . -
FIG. 14 is a schematic of an exemplary method for controlling articulation of the joint ofFIG. 13 , according to one or more embodiments of the disclosure. -
FIGS. 15A and 15B are top exposed views of the wrist ofFIG. 13 illustrating example operation of the method ofFIG. 14 . -
FIG. 16 is a schematic of another exemplary method for controlling articulation of the joint ofFIG. 13 , according to one or more embodiments of the disclosure. -
FIGS. 17A and 17B are plots illustrating an exemplary differential control for actuating the wrist, according to one or more embodiments of the disclosure. -
FIG. 18 illustrates a force versus distance curve of an exemplary closure system, according to one or more embodiments of the disclosure. - The present disclosure is related to robotic surgery and, more particularly, to an articulable wrist or joint used to position an end effector of a surgical tool, to systems for articulating the wrist into a desired position when subject to an external load and maintaining that position when subject to the load, systems for homing the articulable wrist, and systems for ensuring accurate positioning of the wrist.
-
FIGS. 1-3 illustrate the structure and operation of an example robotic surgical system and associated components thereof. While applicable to robotic surgical systems, it is noted that the principles of the present disclosure may equally or alternatively be applied to non-robotic surgical systems, without departing from the scope of the disclosure. -
FIG. 1 is a block diagram of an example roboticsurgical system 100 that may incorporate some or all of the principles of the present disclosure. As illustrated, thesystem 100 can include at least onemaster control console 102 a and at least onerobotic manipulator 104. Therobotic manipulator 104 may be mechanically and/or electrically coupled to or otherwise include one or morerobotic arms 106. In some embodiments, therobotic manipulator 104 may be mounted to a transport cart (alternately referred to as an “arm cart”) that enables mobility of therobotic manipulator 104 and the associatedrobotic arms 106. Eachrobotic arm 106 may include and otherwise provide a tool driver where one or more surgical instruments ortools 108 may be mounted for performing various surgical tasks on apatient 110. Operation of therobotic arms 106, the corresponding tool drivers, and theassociated tools 108 may be directed by aclinician 112 a (e.g., a surgeon) from themaster control console 102 a. - In some embodiments, a second
master control console 102 b (shown in dashed lines) operated by asecond clinician 112 b may also help direct operation of therobotic arms 106 and thetools 108 in conjunction with thefirst clinician 112 a. In such embodiments, for example, eachclinician 112 a,b may control differentrobotic arms 106 or, in some cases, complete control of therobotic arms 106 may be passed between theclinicians 112 a,b. In some embodiments, additional robotic manipulators having additional robotic arms may be utilized during surgery on apatient 110, and these additional robotic arms may be controlled by one or more of themaster control consoles 102 a,b. - The
robotic manipulator 104 and themaster control consoles 102 a,b may communicate with one another via acommunications link 114, which may be any type of wired or wireless communications link configured to carry suitable types of signals (e.g., electrical, optical, infrared, etc.) according to any communications protocol. The communications link 114 may be an actual physical link or it may be a logical link that uses one or more actual physical links. When the link is a logical link the type of physical link may be a data link, uplink, downlink, fiber optic link, point-to-point link, for example, as is well known in the computer networking art to refer to the communications facilities that connect nodes of a network. Accordingly, theclinicians 112 a,b may be able to remotely control therobotic arms 106 via the communications link 114, thus enabling theclinicians 112 a,b to operate on thepatient 110 remotely. -
FIG. 2 is one example embodiment of themaster control console 102 a that may be used to control operation of therobotic manipulator 104 ofFIG. 1 . As illustrated, themaster control console 102 a can include asupport 202 on which theclinician 112 a,b (FIG. 1 ) can rest his/her forearms while gripping one or moreuser input devices 203, one in each hand. Theuser input devices 203 may comprise, for example, physical controllers such as, but not limited to, a joystick, exoskeletal gloves, a master manipulator, etc., and may be movable in multiple degrees of freedom to control the position, orientation, and operation of the surgical tool(s) 108 (FIG. 1 ). In some embodiments, themaster control console 102 a may further include one ormore foot pedals 204 engageable by theclinician 112 a,b to change the configuration of the surgical system and/or generate additional control signals to control operation of the surgical tool(s) 108. - The
user input devices 203 and/or thefoot pedals 204 may be manipulated while theclinician 112 a,b (FIG. 1 ) views the procedure via avisual display 206. Images displayed on thevisual display 206 may be obtained from an endoscopic camera or “endoscope.” In some embodiments, thevisual display 206 may include or otherwise incorporate a force feedback meter or “force indicator” that provides theclinician 112 a,b with a visual indication of the magnitude of force being assumed by the surgical tool (i.e., a cutting instrument or dynamic clamping member) and in which direction. As will be appreciated, other sensor arrangements may be employed to provide themaster control console 102 a with an indication of other surgical tool metrics, such as whether a staple cartridge has been loaded into an end effector or whether an anvil has been moved to a closed position prior to firing, for example. -
FIG. 3 depicts one example of therobotic manipulator 104 that may be used to operate a plurality ofsurgical tools 108, according to one or more embodiments. As illustrated, therobotic manipulator 104 may include a base 302 that supports a vertically extendingcolumn 304. A plurality of robotic arms 106 (three shown) may be operatively coupled to thecolumn 304 at acarriage 306 that can be selectively adjusted to vary the height of therobotic arms 106 relative to thebase 302, as indicated by the arrow A. - The
robotic arms 106 may comprise manually articulable linkages, alternately referred to as “set-up joints.” In the illustrated embodiment, asurgical tool 108 is mounted tocorresponding tool drivers 308 provided on eachrobotic arm 106. Eachtool driver 308 may include one or more drivers or motors (sometimes referred to as drivers 610 a-f) used to interact with a corresponding one or more drive inputs of thesurgical tools 108, and actuation of the drive inputs causes the associatedsurgical tool 108 to operate. - One of the
surgical tools 108 may comprise animage capture device 310, such as an endoscope, which may include, for example, a laparoscope, an arthroscope, a hysteroscope, or may alternatively include some other imaging modality, such as ultrasound, infrared, fluoroscopy, magnetic resonance imaging, or the like. Theimage capture device 310 has a viewing end located at the distal end of an elongate shaft, which permits the viewing end to be inserted through an entry port into an internal surgical site of a patient's body. Theimage capture device 310 may be communicably coupled to the visual display 206 (FIG. 2 ) and capable of transmitting images in real-time to be displayed on thevisual display 206. - The remaining surgical tools may be communicably coupled to the user input devices held by the
clinician 112 a,b (FIG. 1 ) at themaster control console 102 a (FIG. 2 ). Movement of therobotic arms 106 and associatedsurgical tools 108 may be controlled by theclinician 112 a,b manipulating the user input devices. As described in more detail below, thesurgical tools 108 may include or otherwise incorporate an end effector mounted on a corresponding articulable wrist pivotally mounted on a distal end of an associated elongate shaft. The elongate shaft permits the end effector to be inserted through entry ports into the internal surgical site of a patient's body, and the user input devices also control movement (actuation) of the end effector. - In use, the
robotic manipulator 104 is positioned close to a patient requiring surgery and is then normally caused to remain stationary until a surgical procedure to be performed has been completed. Therobotic manipulator 104 typically has wheels or castors to render it mobile. The lateral and vertical positioning of therobotic arms 106 may be set by theclinician 112 a,b (FIG. 1 ) to facilitate passing the elongate shafts of thesurgical tools 108 and theimage capture device 310 through the entry ports to desired positions relative to the surgical site. When thesurgical tools 108 andimage capture device 310 are so positioned, therobotic arms 106 andcarriage 306 can be locked in position. -
FIG. 4 is an isometric side view of an examplesurgical tool 400 that may incorporate some or all of the principles of the present disclosure. Thesurgical tool 400 may be the same as or similar to the surgical tool(s) 108 ofFIGS. 1 and 3 and, therefore, may be used in conjunction with a robotic surgical system, such as the roboticsurgical system 100 ofFIG. 1 . As illustrated, thesurgical tool 400 includes anelongated shaft 402, anend effector 404, an articulable wrist 406 (alternately referred to as a “wrist joint”) that couples theend effector 404 to the distal end of theshaft 402, and adrive housing 408 coupled to the proximal end of theshaft 402. In applications where thesurgical tool 400 is used in conjunction with a robotic surgical system, thedrive housing 408 can include coupling features that releasably couple thesurgical tool 400 to the robotic surgical system. The principles of the present disclosure, however, are equally applicable to surgical tools that are non-robotic and otherwise capable of manual manipulation. - The terms “proximal” and “distal” are defined herein relative to a robotic surgical system having an interface configured to mechanically and electrically couple the surgical tool 400 (e.g., the drive housing 408) to a robotic manipulator. The term “proximal” refers to the position of an element closer to the robotic manipulator and the term “distal” refers to the position of an element closer to the
end effector 404 and thus further away from the robotic manipulator. Moreover, the use of directional terms such as above, below, upper, lower, upward, downward, left, right, and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward or upper direction being toward the top of the corresponding figure and the downward or lower direction being toward the bottom of the corresponding figure. - The
surgical tool 400 can have any of a variety of configurations capable of performing one or more surgical functions. In the illustrated embodiment, theend effector 404 comprises a surgical stapler, alternately referred to as an “endocutter,” configured to cut and staple (fasten) tissue. As illustrated, theend effector 404 includes opposingjaws jaws jaws end effector 404 between the open and closed positions. - In the illustrated embodiment, the
first jaw 410 may be characterized or otherwise referred to as a “cartridge” jaw, and thesecond jaw 412 may be characterized or otherwise referred to as an “anvil” jaw. More specifically, thefirst jaw 410 may include a frame that houses or supports a staple cartridge, and thesecond jaw 412 is pivotally supported relative to thefirst jaw 410 and defines a surface that operates as an anvil to form staples ejected from the staple cartridge during operation. In use, thesecond jaw 412 is rotatable between an open, unclamped position and a closed, clamped position. In other embodiments, however, thefirst jaw 410 may move (rotate) relative to thesecond jaw 412, without departing from the scope of the disclosure. - The
wrist 406 enables theend effector 404 to articulate (pivot) relative to theshaft 402 and thereby position theend effector 404 at desired orientations and locations relative to a surgical site.FIG. 5 illustrates the potential degrees of freedom in which thewrist 406 may be able to articulate (pivot). Thewrist 406 can have any of a variety of configurations. In general, thewrist 406 comprises a joint configured to allow pivoting movement of theend effector 404 relative to theshaft 402. The degrees of freedom of thewrist 406 are represented by three translational variables (i.e., surge, heave, and sway), and by three rotational variables (i.e., Euler angles or roll, pitch, and yaw). The translational and rotational variables describe the position and orientation of a component of a surgical system (e.g., the end effector 404) with respect to a given reference Cartesian frame. As depicted inFIG. 5 , “surge” refers to forward and backward translational movement, “heave” refers to translational movement up and down, and “sway” refers to translational movement left and right. With regard to the rotational terms, “roll” refers to tilting side to side, “pitch” refers to tilting forward and backward, and “yaw” refers to turning left and right. - The pivoting motion can include pitch movement about a first axis of the wrist 406 (e.g., X-axis), yaw movement about a second axis of the wrist 406 (e.g., Y-axis), and combinations thereof to allow for 360° rotational movement of the
end effector 404 about thewrist 406. In other applications, the pivoting motion can be limited to movement in a single plane, e.g., only pitch movement about the first axis of thewrist 406 or only yaw movement about the second axis of thewrist 406, such that theend effector 404 moves only in a single plane. - Referring again to
FIG. 4 , thesurgical tool 400 may include a plurality of drive members or the like (obscured inFIG. 4 ) that form part of an actuation system configured to facilitate articulation of thewrist 406 and actuation (operation) of the end effector 404 (e.g., clamping, firing, rotation, articulation, energy delivery, etc.). Some drive members may extend to thewrist 406, and selective actuation of these drive members causes theend effector 404 to articulate (pivot) relative to theshaft 402 at thewrist 406. Theend effector 404 is depicted inFIG. 4 in the unarticulated position where a longitudinal axis A2 of theend effector 404 is substantially aligned with the longitudinal axis A1 of theshaft 402, such that theend effector 404 is at a substantially zero angle relative to theshaft 402. In the articulated position, the longitudinal axes A1, A2 would be angularly offset from each other such that theend effector 404 is at a non-zero angle relative to theshaft 402. - Other drive members may extend to the
end effector 404, and selective actuation of those drive members may cause theend effector 404 to actuate (operate). In the illustrated embodiment, actuating theend effector 404 may comprise closing and/or opening thesecond jaw 412 relative to the first jaw 410 (or vice versa), thereby enabling theend effector 404 to grasp (clamp) onto tissue. In addition, once tissue is grasped or clamped between the opposingjaws end effector 404 may further comprise “firing” theend effector 404, which may refer to causing a cutting element or knife (not visible) to advance distally within aslot 414 defined in thesecond jaw 410. As it moves distally, the cutting element may transect any tissue grasped between the opposingjaws second jaw 412. The deployed staples may form multiple rows of staples that seal opposing sides of the transected tissue. - In some embodiments, the
surgical tool 400 may be configured to apply energy to tissue, such as radio frequency (RF) energy. In such cases, actuating theend effector 404 may further include applying energy to tissue grasped or clamped between two opposing jaws to cauterize or seal the captured tissue, following which the tissue may be transected. - In some embodiments, the
surgical tool 400 may further include amanual closure device 416 accessible to a user on the exterior of thedrive housing 408. As illustrated, themanual closure device 416 may comprise a knob that may be grasped by the user. Themanual closure device 416 may be operatively coupled to various gears and/or drive members within thedrive housing 408 to allow a clinician to manually open and close thejaws jaws manual closure device 416. Themanual closure device 416 may be particularly useful to a clinician when thesurgical tool 400 is detached from a surgical robot, since having the capability to open and close thejaws jaws surgical tool 400 is still attached to a surgical robot, the clinician can rotate themanual closure device 416 in an attempt to open theend effector 404. -
FIG. 6 depicts a bottom view of thedrive housing 408, according to one or more embodiments. As illustrated, thedrive housing 408 may include atool mounting portion 602 used to operatively couple thedrive housing 408 to atool driver 604. Thetool driver 604 may be the same as or similar to thetool drivers 308 ofFIG. 3 , and may thus be operable in conjunction with therobotic manipulator 104 ofFIGS. 1 and 3 . Mounting thedrive housing 408 to thetool driver 604 places thedrive housing 408 in communication with acomputer system 606, which may communicate with or otherwise form part of themaster controllers 102 a,b (FIG. 1 ). The computer system 608 monitors and directs operation of thedrive housing 408 via operation of thetool driver 604, thus enabling a user (e.g., theclinicians 112 a,b ofFIG. 1 ) to control operation of thedrive housing 408 by working through themaster controller 102 a,b - The
tool mounting portion 602 includes and otherwise provides an interface that mechanically, magnetically, and/or electrically couples thedrive housing 408 to thetool driver 604. In at least one embodiment, thetool mounting portion 602 couples thedrive housing 408 to thetool driver 604 via a sterile barrier (not shown). As illustrated, the interface of thetool mounting portion 602 can include and support a plurality of inputs, shown asdrive inputs corresponding driver tool driver 604. Each drive input 608 a-f and corresponding driver 610 a-f provide or define one or more matable surface features 612 and 614, respectively, configured to facilitate mating engagement between the opposing surface features 612, 614 such that movement (rotation) of a given driver 610 a-f correspondingly moves (rotates) the associated drive input 608 a-f. - Each driver 610 a-f of the
tool driver 604 may include or otherwise comprise amotor 616 configured to actuate the corresponding driver 610 a-f, and actuation of a given driver 610 a-f correspondingly causes actuation of the mated drive input 608 a-f, which facilitates operation of the mechanics of thedrive housing 408. More specifically, actuation of themotors 616 may cause rotational movement of the corresponding driver 610 a-f, which, in turn, rotates the associated drive input 608 a-f. Eachmotor 616 may be in communication with thecomputer system 606 and, based on input signals provided by a user (e.g., a surgeon), thecomputer system 606 may selectively cause any of themotors 616 to actuate and thereby drive the corresponding driver 610 a-f. - In some embodiments, actuation of the
first drive input 608 a via thefirst driver 610 a may control rotation of theshaft 402 about its longitudinal axis A1. Depending on the rotational direction of thefirst drive input 608 a, theshaft 402 can be rotated clockwise or counter-clockwise, thus correspondingly rotating the end effector 404 (FIG. 4 ) in the same direction. Actuation of the second andthird drive inputs 608 b,c via the second andthird drivers 610 b,c, respectively, may control articulation of theend effector 404 at the wrist 406 (FIG. 4 ). Actuation of the fourth andfifth drive inputs 608 d,e via the fourth andfifth drivers 610 d,e, respectively, may cause an outer portion of the shaft 402 (referred to herein as a “closure tube”) to advance and retract, which closes and opens thejaws 410, 412 (FIG. 4 ). Lastly, actuation of thesixth drive input 608 f via thesixth driver 610 f may cause theend effector 404 to fire, which may entail distal deployment of a cutting element to transect tissue grasped by thejaws first jaw 410. - The
tool mounting portion 602 may further include one or more electrical connectors 618 (two shown) configured to mate with corresponding electrical connections 620 (two shown) provided by thetool driver 604 to facilitate communication between thedrive housing 408 and thetool driver 604. Alternately, thedrive housing 408 can wirelessly communicate with thetool driver 604, such as through a near field communication connection. Thedrive housing 408 may further house or otherwise include aninternal computer 622 that may include a memory 624 and/or amicroprocessor 626. The memory 624 may include one or more databases or libraries that store data relating to thedrive housing 408 and, more particularly, to the surgical tool 400 (FIG. 4 ). In some embodiments, the memory 624 may include non-transitory, computer-readable media such as a read-only memory (ROM), which may be PROM, EPROM, EEPROM, or the like. Mating thedrive housing 408 to thetool driver 604 places theinternal computer 622 in communication with thecomputer system 606. - The
computer system 606 may be programmed and otherwise configured to monitor operation of the surgical tool 400 (FIG. 4 ) using various sensors and/or electromechanical devices, collectively referred to herein as “monitoring devices.” Each monitoring device may be designed to monitor one or more operational parameters of thesurgical tool 400 and report measured operational parameters to thecomputer system 606 for processing. Thecomputer system 606, for example, may be in communication with one ormore torque sensors 628 and/or one or morerotary encoders 630, each of which may be characterized as a monitoring device designed to monitor operational parameters of thesurgical tool 400. Thetorque sensors 628, for instance, may be configured to monitor torque, and therotary encoders 630 may be configured to monitor motion (rotational or linear). - The
torque sensors 628 and therotary encoders 630 may be incorporated into themotors 616 of some or all of the drivers 610 a-f, but could alternatively be operatively coupled to one or more of the drive inputs 608 a-f. Thetorque sensors 628 may be configured to measure the real-time torque loading on themotors 616, which corresponds to the torque loading assumed by the drivers 610 a-f and/or the drive inputs 608 a-f. Therotary encoders 630 may measure the rotational motion or output of themotors 616, which corresponds to the rotational motion of the drivers 610 a-f and/or the drive inputs 608 a-f. Monitoring torque loading and rotational motion of themotors 616 may help determine if thesurgical tool 400 is operating in accordance with the commands provided by thecomputer system 606. - Referring to
FIGS. 7A and 7B andFIGS. 8A and 8B , illustrated are exposed isometric views of the interior of thedrive housing 408, according to one or more embodiments. The upper portion of thedrive housing 408 is omitted inFIGS. 7A-7B to allow viewing of the internal working components and parts, and both the upper and lower portions of thedrive housing 408 are omitted inFIGS. 8A-8B to allow viewing of the internal working components and parts. In addition, several component parts that would otherwise be included within thedrive housing 408 are omitted inFIGS. 7A-7B and 8A-8B to simplify the figures and enable discussion of the depicted component parts. - Referring first to
FIG. 7A , afirst drive shaft 702 a is coupled to thefirst drive input 608 a (FIG. 6 ) such that actuation and rotation of thefirst drive input 608 a correspondingly rotates thefirst drive shaft 702 a. Ahelical drive gear 704 is coupled to thefirst drive shaft 702 a and rotates as thefirst drive shaft 702 a rotates. Thehelical drive gear 704 intermeshes with a helical drivengear 706, which is operatively coupled to theshaft 402 and, more particularly, to an inner grounding member orshaft 708 that forms part of theshaft 402. Theinner grounding shaft 708 extends concentrically within an outer portion of theshaft 402 referred to herein as the “closure tube.” Accordingly, actuation of thefirst drive input 608 a drives thefirst drive shaft 702 a and correspondingly drives theinner grounding shaft 708 to rotate theshaft 402 about the longitudinal axis A1. - A
second drive shaft 702 b may be coupled to thesecond drive input 608 b (FIG. 6 ) such that actuation and rotation of thesecond drive input 608 b correspondingly rotates thesecond drive shaft 702 b. In some examples, a drive train or gearing may be provided to adjust the mechanical advantage output from one or more motors of the robotic manipulator (not illustrated). For example, if thesecond driver 610 b (FIG. 6 ) outputs relatively low torque, one or more intermeshed gears may be utilized to increase the torque imparted by thesecond driver 610 b on thedrive shaft 702 b. As best exemplified inFIGS. 8A-8B , aspur gear 709 a is attached and keyed to thesecond drive shaft 702 b such that thespur gear 709 a rotates in unison withdrive shaft 702 b. Also, acompound pinion gear 710 a is rotatably attached to thesecond drive shaft 702 b, such that thecompound pinion gear 710 a is rotatable about and relative to thesecond drive shaft 702 b. As illustrated, thecompound pinion gear 710 a includes afirst pinion gear 711 a and asecond pinion gear 713 a that are rigidly connected together such that they rotate together about thesecond drive shaft 702 b. Thesecond pinion gear 713 a of thecompound pinion gear 710 a intermeshes with a first drivenrack 712 a such that, as thecompound pinion gear 710 a is rotated in a first rotational direction, the first drivenrack 712 a correspondingly translates in a first longitudinal direction; and, as thecompound pinion gear 710 a is rotated in a second rotational direction, the first drivenrack 712 a correspondingly translates in a second longitudinal direction opposite the first longitudinal direction. - In addition, an
idler assembly 715 a (FIGS. 8A-8B ) is provided to transfer rotation of thesecond drive shaft 702 b to thecompound pinion gear 710 a and thereby effectuate translation of the first drivenrack 712 a in the first or second longitudinal direction. In the illustrated example, theidler assembly 715 a is a compound gear having afirst idler 717 a and asecond idler 719 a that is rigidly connected to thefirst idler 717 a such that they rotate together in unison. Here, thefirst idler 717 a meshes with thespur gear 709 a that is keyed to thesecond drive shaft 702 b, and thesecond idler 719 a meshes with thefirst pinion gear 711 a of thecompound pinion gear 710 a to thereby drive the first drivenrack 712 a. Thus, thesecond driver 610 b (FIG. 6 ) rotates thesecond drive input 608 b, which in turn rotates thesecond drive shaft 702 b and thespur gear 709 a connected thereto. Thespur gear 709 a imparts rotation to thefirst idler 717 a of theidler assembly 715 a, which in turn also imparts rotation on thesecond idler 719 a thereof as it is keyed to thefirst idler 717 a. Thesecond idler 719 a of theidler assembly 715 a imparts rotation on thefirst pinion gear 711 a of thecompound pinion gear 710 a, which in turn also imparts rotation on thesecond pinion gear 713 a of thecompound pinion gear 710 a as it is keyed to thefirst pinion gear 711 a. As described above, such rotation of thesecond pinion gear 713 a causes translation of thefirst drive rack 712 a. - The illustrated drive train transferring power between the
second driver 610 b (FIG. 6 ) and the first drivenrack 712 a is configured with a cumulative gear ratio that increases the torque that thecompound pinion gear 710 a exerts on thefirst drive rack 712 a beyond what is initially applied to thedrive input 608 b by thesecond driver 610 b. In particular, because thespur gear 709 a is smaller (i.e., less teeth) than thefirst idler 717 a with which it meshes and because thesecond idler 719 a is smaller (i.e., less teeth) than the first pinion gear 711 with which it meshes, the torque acting on thecompound pinion gear 710 a that drives thefirst drive rack 712 a is significantly larger than the torque initially applied on thesecond drive shaft 702 b via thesecond driver 610 b. - The first driven
rack 712 a includes afirst fork 714 a matable with afirst articulation yoke 716 a. More specifically, thefirst fork 714 a is configured to be received within anannular slot 718 a (FIGS. 7A and 8B ) defined in thefirst articulation yoke 716 a, which allows thefirst articulation yoke 716 a to rotate about the longitudinal axis A1 as theinner grounding shaft 708 rotates. Moreover, engagement between thefirst fork 714 a and theannular slot 718 a allows the first drivenrack 712 a to drive thefirst articulation yoke 716 a along the longitudinal axis A1 (distally or proximally) as acted upon by rotation of thesecond drive shaft 702 b. Thefirst articulation yoke 716 a may be coupled to afirst drive member 720 a, which extends distally to the wrist 406 (FIG. 4 ). As illustrated, thefirst drive member 720 a is arranged within a corresponding slot defined in theinner grounding shaft 708, such that theinner grounding shaft 708 guides thefirst drive member 720 a as they extend distally together to the wrist 406 (FIG. 8 ). Axial movement of thefirst articulation yoke 716 a along the longitudinal axis A1 correspondingly moves thefirst drive member 720 a, which causes thewrist 406 and the end effector 404 (FIG. 4 ) to articulate. - A
third drive shaft 702 c is coupled to thethird drive input 608 c (FIG. 6 ) such that actuation and rotation of thethird drive input 608 c correspondingly rotates thethird drive shaft 702 c. Similar to the description of thesecond drive shaft 702 b coupled to thesecond drive input 608 b, a drive train or gearing may be provided to adjust mechanical advantage and thus vary the torque or speed initially applied by thethird driver 610 c (FIG. 6 ) to thethird drive shaft 702 c. In the illustrated example, aspur gear 709 b is attached and keyed to thethird drive shaft 702 c such that thespur gear 709 b rotates in unison withthird drive shaft 702 c. Acompound pinion gear 710 b is rotatably attached to thethird drive shaft 702 c such that thecompound pinion gear 710 b may rotate about and relative to thethird drive shaft 702 c. As illustrated, thecompound pinion gear 710 b includes afirst pinion gear 711 b and asecond pinion gear 713 b that are rigidly connected together such that they rotate together about thethird drive shaft 702 c. Thesecond pinion gear 713 b of thecompound pinion gear 710 b intermeshes with a second drivenrack 712 b such that rotating thecompound pinion gear 710 b in a first rotational direction correspondingly translates the second drivenrack 712 b in a first longitudinal direction. Rotating thecompound pinion gear 710 b in a second rotational direction correspondingly translates the second drivenrack 712 b in a second longitudinal direction opposite the first longitudinal direction. - In addition, an
idler assembly 715 b is provided to transfer rotation of thethird drive shaft 702 c to thecompound pinion gear 710 b and thereby effectuate translation of the second drivenrack 712 b in the first or second longitudinal direction. In the illustrated example, theidler assembly 715 b is a compound gear having afirst idler 717 b and a second idler 719 b that is rigidly connected to thefirst idler 717 b such that they rotate together in unison. Here, thefirst idler 717 b meshes with thespur gear 709 b that is keyed to thethird drive shaft 702 c, and the second idler 719 b meshes with thefirst pinion gear 711 b of thecompound pinion gear 710 b to thereby drive the second drivenrack 712 b. Thus, thethird driver 610 c (FIG. 6 ) rotates thethird drive input 608 c, which in turn rotates thethird drive shaft 702 c and thespur gear 709 b connected thereto. Thespur gear 709 b imparts rotation to thefirst idler 717 b of theidler assembly 715 b, which in turn also imparts rotation on the second idler 719 b thereof as it is keyed to thefirst idler 717 b. The second idler 719 b of theidler assembly 715 b imparts rotation on thefirst pinion gear 711 b of thecompound pinion gear 710 b, which in turn also imparts rotation on thesecond pinion gear 713 b of thecompound pinion gear 710 b as it is keyed to thefirst pinion gear 711 b. As described above, such rotation of thesecond pinion gear 713 b causes translation of thefirst drive rack 712 b. The illustrated drive train transferring power between thethird driver 610 c and the second drivenrack 712 b is configured with a cumulative gear ratio that results in increased output torque acting on thecompound pinion gear 710 b and thereby exerted on thesecond drive rack 712 b beyond what is initially applied to thethird drive input 608 c by thethird driver 610 c. - The second driven
rack 712 b includes asecond fork 714 b matable with asecond articulation yoke 716 b. More particularly, thesecond fork 714 b is configured to be received within anannular slot 718 b defined in thesecond articulation yoke 716 b, which allows thesecond articulation yoke 716 b to rotate about the longitudinal axis A1 as theinner grounding shaft 708 rotates. Moreover, engagement between thesecond fork 714 b and theannular slot 718 b allows the second drivenrack 712 b to drive thesecond articulation yoke 716 b along the longitudinal axis A1 (distally or proximally) as acted upon by rotation of thethird drive shaft 702 c. Thesecond articulation yoke 716 b may be coupled to asecond drive member 720 b (FIG. 7A ), which extends distally to the wrist 406 (FIG. 4 ). Thesecond drive member 720 b is arranged within a corresponding slot defined in theinner grounding shaft 708, such that theinner grounding shaft 708 guides thesecond drive member 720 b as they extend distally together to the wrist 406 (FIG. 8 ). Axial movement of thesecond articulation yoke 716 b along the longitudinal axis A1 correspondingly moves thesecond drive member 720 b, which causes thewrist 406 and the end effector 404 (FIG. 4 ) to articulate. - Accordingly, axial movement of the first and second articulation yokes 716 a,b, along the longitudinal axis A1 cooperatively actuates the
drive members 720 a,b and, thereby, articulates theend effector 404 as further described herein with reference toFIGS. 9A-9B and 10A-10B . In at least one embodiment, the first and second articulation yokes 716 a,b protagonistically operate such that one of the articulation yokes 716 a,b pulls one of thedrive members 720 a,b proximally while theother articulation yoke 716 a,b pushes theother drive member 720 a,b distally. In some embodiments, however, the first and second articulation yokes 716 a,b may be operated independently without the other being operated (affected), for example, they may operate antagonistically where one reduces the force effect of another. In antagonistic operation, one of thearticulation yolks 716 a,b pulls (or pushes) thedrive member 720 a,b associated therewith proximally (or distally) with a first force while the other one of thearticulation yolks 716 a,b pulls (or pushes) thedrive member 720 a,b associated therewith proximally (or distally) with a second force, where the first force is larger than the second force such that the first force can overcome the second force, as well as the internal losses of the device (i.e., friction) and loads imparted on theend effector 404 via the external environment, thereby ensuring that thearticulation yolk 716 a,b providing the first force moves proximally (or distally) while thearticulation yolk 716 a,b providing the second force moves distally (or proximally). As described below, the computer system 606 (FIG. 6 ) may be configured to control thedrivers 610 b,c (FIG. 6 ) that drive thedrive inputs 608 b-c andinterconnected drive shafts 702 b-c to thereby synchronize actuation of the articulation yokes 716 a,b. - A
fourth drive shaft 702 d (FIG. 7A ) and afifth drive shaft 702 e (FIG. 7B ) may be coupled to the fourth andfifth drive inputs 608 d,e (FIG. 6 ), respectively, such that actuation and rotation of the fourth andfifth drive inputs 608 d,e correspondingly rotates the fourth andfifth drive shafts 702 d,e. Rotation of the fourth andfifth drive shafts 702 d,e may cause a portion of theshaft 402 to advance or retract. More specifically, the outer portion of theshaft 402 may comprise aclosure tube 722 that is axially translated to move thejaws 410, 412 (FIG. 4 ) between open and closed positions. As illustrated, eachdrive shaft 702 d,e has aspur gear 724 attached thereto, and both spur gears 724 are positioned to mesh with aprimary drive gear 725 mounted to aclosure yoke 726. - The
closure yoke 726 is rotatably mounted to theclosure tube 722 but fixed axially thereto. This allows theclosure tube 722 to rotate as theinner grounding shaft 708 rotates, but also allows theclosure yoke 726 to advance or retract theclosure tube 722. A projection 727 (FIG. 8A ) extends from or is otherwise coupled to theclosure yoke 726, and the projection interacts with a camming surface or slot defined within theprimary drive gear 725 to facilitate axial movement of theclosure yoke 726. Accordingly, rotating the spur gears 724 causes theprimary drive gear 725 to rotate, which correspondingly causes theclosure yoke 726 and theinterconnected closure tube 722 to axially translate. - The
primary drive gear 725 may also be operatively coupled to themanual closure device 416 arranged on the exterior of thedrive housing 408. As illustrated, themanual closure device 416 may include adrive gear 728 that intermeshes with a drivengear 729 mounted to theprimary drive gear 725. Consequently, a user can grasp and rotate themanual closure device 416 to correspondingly rotate theprimary drive gear 725 and thereby drive thedrive gear 728 against the drivengear 729 to move the closure yoke 426 distally and proximally to close and open thejaws 410, 412 (FIG. 4 ), as generally described above. In one example, of theprimary drive gear 725 is intermeshed between the spur gears 724 and comprises a central aperture that rotatably mounts theprimary drive gear 725 within the drive housing 408 (FIGS. 7A-7B ) relative to the spur gears 724. A spiral cam slot is defined in theprimary drive gear 725 and the projection 727 (FIG. 8A ) of the closure yoke 726 (FIGS. 7A-7B ) is received therein. Theprimary drive gear 725 is rotatable about an axis extending through the central aperture as acted upon by the spur gears 724. As theprimary drive gear 725 rotates, the projection follows the spiral cam slot, and the curvature of the spiral cam slot urges theinterconnected closure yoke 726 to translate longitudinally relative to theprimary drive gear 725. When theclosure yoke 726 moves distally, the closure tube 722 (FIGS. 7A-7B ) correspondingly moves in the distal direction and causes thejaws 410, 412 (FIG. 4 ) to close. In contrast, when theclosure yoke 726 moves proximally, theclosure tube 722 correspondingly moves in the proximal direction and causes thejaws -
FIGS. 9A and 9B illustrate exposed bottom views of thesurgical tool 400, according to one or more embodiments. Much of the gearing and actuation mechanisms described above are depicted, but the entirety of thedrive housing 408 and theclosure tube 722 of theshaft 402 are omitted inFIGS. 9A-9B to allow viewing of the internal working components and parts utilized to articulate thedrive members 720 a,b and thewrist 406. In addition, several component parts that would otherwise be included within thedrive housing 408 are omitted in these figures to simplify the figures and enable discussion of the depicted component parts. - With reference to
FIG. 9A , theinner grounding shaft 708 extends distally within theshaft 402 and is connected to thewrist 406. Thedrive members 720 a,b extend distally towards thewrist 406 within correspondingslots 802 a,b defined within theinner grounding shaft 708. The correspondingslots 802 a,b may be provided on opposite sides of theinner grounding shaft 708, or may be defined elsewhere about theinner grounding shaft 708 in other examples. As described below, movement of thedrive members 720 a,b articulates thewrist 406. Also, theinner grounding shaft 708 is configured to effect rotation of thewrist 406 about the longitudinal axis A1, even when thewrist 406 is articulated to an angularly offset position relative to the longitudinal axis A1. - In the illustrated example, a locking or grounding recess (obscured from view) is formed into a bottom side of the distal end of the
inner grounding shaft 708, and the grounding recess defines a pair of lockingtabs 804 a,b configured to interlock with other componentry of thewrist 406. Here, abase 806 of thewrist 406 is integrally secured within the grounding recess of theinner grounding shaft 708 via the lockingtabs 804 a,b such that theinner grounding shaft 708 carries thewrist 406 as it rotates about the longitudinal axis A1 upon actuation of thefirst drive input 608 a. In addition, theslots 802 a,b extend through the grounding recess and the lockingtabs 804 a,b, with lower boundary of theslots 802 a,b being defined by an upper surface of thebase 806, as described below. - The
wrist 406 further includes anarticulation member 808 to which theend effector 404 may be mounted. Thearticulation member 808 is coupled to thebase 806 and thedrive members 720 a,b, such that movement of thedrive members 720 a,b articulates thearticulation member 808 relative to thebase 806. Thus, thewrist 406 and theend effector 404 extending distally therefrom may be angularly offset via movement of thedrive members 720 a,b. - In
FIG. 9B theinner grounding shaft 708 has been removed. As illustrated, thedrive members 720 a,b are interconnected at their distal ends via a third link member, described herein with reference toFIG. 10B and referred to herein as a “distal link.” Thus, thedrive members 720 a,b and the distal link together comprise a linkage configured to articulate thearticulation member 808 relative to the base 806 in a plane parallel to the longitudinal axis A1. With this configuration, thedrive members 720 a,b translate antagonistically within their correspondingslots 802 a,b (FIG. 9A ) along the longitudinal axis A1, such that as thefirst drive member 720 a moves distally thesecond drive member 702 b moves proximally, and vice versa. More specifically, distal movement of thefirst drive member 720 a acts on thearticulation member 808 and causes thearticulation member 808 to rotate clockwise and thereby push thesecond drive member 720 b proximally. Thus, thefirst drive member 720 a moves distally as thesecond drive member 720 b moves proximally, thereby causing thewrist 406 to articulate in the plane such that it is angularly offset at a non-zero angle relative to theinner grounding shaft 708. As mentioned above, thewrist 406 is also configured to rotate with theinner grounding shaft 708 about the longitudinal axis A1, and thereby rotate the plane in which thearticulation member 808 articulates (360° about the longitudinal axis A1). -
FIG. 10A illustrates a bottom view of thewrist 406, according to one or more embodiments. As illustrated, thebase 806 is attached to theinner grounding shaft 708 and arranged within theclosure tube 722. Here, theclosure tube 722 includes adistal clevis 1002 having a pair ofapertures 1004. In addition, aclosure link 1006 having a pair ofpins base 806 and theinner grounding shaft 708 are arranged within theclosure tube 722, thefirst pin 1008 of theclosure link 1006 is received within one of theapertures 1004 in thedistal clevis 1002. Theclosure link 1006 is utilized to transmit closure action around the articulation joint. For example, theclosure link 1006 may transmit the closure load or translation of theclosure tube 722 to a closure ring (not illustrated) that may be coupled to thesecond pin 1010 of theclosure link 1006, which pulls or pushes the upper jaw (anvil) open or closed. Also, thearticulation member 808 is able to rotate about an articulation axis A3 that, in the illustrated example, is shown extending through thesecond pin 1010 of theclosure link 1006. -
FIG. 10B illustrates an exploded isometric view of thewrist 406 ofFIG. 10A . As mentioned, the groundingmember 708 includes a grounding recess configured to rigidly secure the base 806 thereto. As illustrated, theinner grounding shaft 708 includes a pair ofgrounding recesses inner grounding shaft 708. As shown, the grounding recesses 1012, 1014 define or provide the lockingtabs 804 a,b configured to engage thebase 806 and inhibit relative rotation there-between. In the illustrated example, thebase 806 includes a pair ofnotches tabs 804 a,b, and the pair ofnotches 1016 a,b define aproximal locking flange 1018 configured to be received within thegrounding recess 1014 when assembled. When thebase 806 is assembled on theinner grounding shaft 708, with lockingtabs 804 a,b extending into thenotches 1016 a,b and theproximal locking flange 1018 extending into thegrounding recess 1014, thebase 806 will rotate together with theinner grounding shaft 708 as described above. - Also, the
slots 802 a,b are illustrated extending longitudinally along theinner grounding shaft 708. Theslots 802 a,b are each defined or bounded by anupper surface 1020 of theinner grounding shaft 708 and alower surface 1022 of theinner grounding shaft 708. In the illustrated example, theupper surfaces 1020 are substantially continuous along the length of theinner grounding shaft 708, but thelower surfaces 1022 are discontinuous or broken due to the grounding recesses 1012, 1014. As illustrated, thelower surfaces 1022 are absent along distal portions of theinner grounding shaft 708 corresponding with thegrounding recess 1012, and thegrounding recess 1014 interposes proximal portions of thelower surfaces 1022 and a distal portion of thelower surfaces 1022 extending along the lockingtabs 804 a,b. - The
base 806, however, includeslower surfaces 1024 that define or bound portions of theslots 802 a,b at locations corresponding with the grounding recesses 1012, 1014. As illustrated, thelower surfaces 1024 of the base 806 extend along theproximal locking flange 1018 of thebase 806, but are discontinuous and broken via thenotches 1016 a,b, and then extend distally therefrom. Thus, when thebase 806 is assembled on theinner grounding shaft 708, theslots 802 a,b are bounded by the upper andlower surface inner grounding shaft 708 along proximal portions thereof and along the lockingtabs 804 a,b; whereas, theslots 802 a,b are bounded by theupper surface 1020 of theinner grounding shaft 708 and thelower surface 1024 of the base 806 at locations along theinner grounding shaft 708 that correspond with the grounding recesses 1012, 1014. - The
base 806 has anupper portion 1026 and alower portion 1028. As illustrated, thelower surfaces 1024 define an upper surface of thelower portion 1028 of thebase 806 and thereby partition theupper portion 1026 from thelower portion 1028. The base 806 also includes anarticulation portion 1030 located at a distal end of thebase 806. Thearticulation portion 1030 is configured to receive thearticulation member 808 and permit rotation of thearticulation member 808 relative to thebase 806. As illustrated, thearticulation portion 1030 includes anextension member 1032 distally extending from theupper portion 1026 of thebase 806, and apivot shaft 1034 oriented on the articulation axis A3 for receiving thearticulation member 808. As shown, thepivot shaft 1034 extends downward from theupper portion 1026 towards thelower portion 1028. In addition, thearticulation portion 1030 includes arecess 1036 formed into thelower portion 1028 at the distal end of thebase 806, which is configured to receive thearticulation member 808 and permit rotation thereof within therecess 1036. As illustrated, thepivot shaft 1034 extends downward into therecess 1036 and adistal face 1038 of thelower portion 1028 includes a curvature that corresponds with a curvature of thearticulation member 808, as described below. - In addition, a
recess 1040 is formed into a distal end of theextension member 1032 for receiving the distal link interconnecting thedrive members 720 a,b as described below. Therecess 1040 is defined by a slidingsurface 1042 on which the distal link may slide and an upperdistal face 1044 of theextension member 1032 on which the distal link may articulate or pivot, and the upperdistal face 1044 may include a curvature that corresponds with a curvature of the distal link. Also in the illustrated example, a lowerdistal face 1046 of theextension member 1032 includes a curvature that corresponds with a curvature of thearticulation member 808. - The
articulation member 808 includes an endeffector mounting portion 1050 at a distal end thereof and acoupling portion 1052 proximally extending from the endeffector mounting portion 1050. The endeffector mounting portion 1050 is configured to receive an end effector, for example, theend effector 404 of thesurgical tool 400 illustrated inFIG. 4 . Thecoupling portion 1052 is configured to be received and rotatably coupled within therecess 1036 in the distal end of thebase 806, such that it may articulate relative to the base 806 when actuated by thedrive members 720 a,b. - The
articulation member 808 includes anaperture 1054 extending through thecoupling portion 1052. Theaperture 1054 is configured to receive thepivot shaft 1034 of thebase 806 and therefore is oriented along the articulation axis A3 when thearticulation member 808 is assembled on thebase 806. When thebase 806 and thearticulation member 808 are assembled together with thepivot shaft 1034 extending through theaperture 1054, thecoupling portion 1052 of thearticulation member 808 is disposed within therecess 1036 defined in thelower portion 1028 thebase 806 such that thearticulation member 808 may rotate about the articulation axis A3 relative to thebase 806. Here, aproximal face 1056 of thecoupling portion 1052 abuts thedistal face 1038 of thebase 806 and thus includes a curvature that corresponds with the curvature of thedistal face 1038 of thelower portion 1028 as described above. Also, aproximal face 1058 of the endeffector mounting portion 1050 abuts the lowerdistal face 1046 of theextension member 1032 when thearticulation member 808 is assembled on thebase 806. Thus, theproximal face 1058 includes a curvature that corresponds with the curvature of the lowerdistal face 1046 of theextension member 1032 and, in some examples, the curvature of theproximal face 1058 is defined by a radius equal to the swept distance that theextension member 1032 extends beyond the articulation axis A3 (i.e., distance between the articulation axis A3 and the lower distal face 1046). - The
articulation member 808 includes a pair ofdrive pins 1060 a,b configured to be engaged by thedrive members 720 a,b. Here, the drive pins 1060 a,b extend upward from anupper surface 1062 of thecoupling portion 1052. When thebase 806 and thearticulation member 808 are assembled together, with thecoupling portion 1052 rotatably disposed within therecess 1036 and with thepivot shaft 1034 extending through theaperture 1054, theupper surface 1062 of thecoupling portion 1052 is substantially aligned or planar with thelower surfaces 1024 of the base 806 such that thedrive members 720 a,b may slide unobstructed thereon. Also, the drive pins 1060 a,b extend upward from theupper surface 1062 of the coupling portion 1052 a sufficient distance such that they may be engaged by thedrive members 720 a,b when riding in theslots 802 a,b. - In the illustrated example, the drive pins 1060 a,b extend upward from the
upper surface 1062 and each terminate at apin end 1064 a,b. Here, the pin ends 1064 a,b are cylindrical members extending upward from the drive pins 1060 a,b and have a reduced diameter from the drive pins 1060 a,b from which they coaxially extend. The pin ends 1064 a,b each define asurface 1066 that is substantially aligned or planar with anupper surface 1068 of the base 806 extending onto theextension member 1032 thereof. Thus, when thebase 806 and thearticulation member 808 are assembled together, the drive pins 1060 a,b extend upward from the slidingsurface 1042 and the pin ends 1064 a,b extend upward from the drive pins 1060 a,b such that thesurfaces 1066 of the pin ends 1064 a,b are oriented parallel with theupper surface 1068 of thebase 806. In other examples, however, the drive pins 1060 a,b and/or the pin ends 1064 a,b may extend upward at different heights, and in some examples the drive pins 1060 a,b do not include pin ends 1064 a,b such that the drive pins 1060 a,b are cylinder shaped members having a uniform diameter. -
FIG. 10B also illustrates thedrive members 720 a,b, each of which provides adistal end articulation member 808. Adrive pin aperture 1072 is provided at thedistal end 1070 a,b of eachdrive member 720 a,b and is configured to receive the drive pins 1060 a,b of thearticulation member 808 when thearticulation member 808 is assembled on thebase 806 and to allow the drive pins 1060 a,b to translate laterally within the correspondingaperture 1072 when thedrive members 720 a,b are actuated to articulate thewrist 406. Thedrive pin apertures 1072 may have various geometries, for example, rectangular or square shape geometries. In the illustrated example, thedrive pin apertures 1072 have a generally rectangular shape with rounded corners, which allows relative translation of the drive pins 1060 a,b during articulation. Regardless of their shape, thedrive pin apertures 1072 are sized to receive the drive pins 1060 a,b or at least a portion of the drive pins 1060 a,b. - Also, the distal ends 1070 a,b of the
drive members 720 a,b are constrained together via adistal link 1074. As mentioned above, thedrive members 720 a,b and thedistal link 1074 together comprise a linkage that articulates thearticulation member 808. Thedistal link 1074 includes a pair ofwings drive members 720 a,b, and eachwing 1076 a,b includes anaperture 1078 configured to receive one of the drive pins 1060 a,b or a portion thereof. In the illustrated example, theapertures 1078 are circular shaped holes configured to receive the pin ends 1064 a,b of the drive pins 1060 a,b. In examples where the drive pins 1060 a,b do not include reduced diameter pin ends 1064 a,b, theapertures 1078 may be circular shaped holes sized to receive the drive pins 1060 a,b. Theapertures 1078 may have various other shapes, however. In some examples, theapertures 1078 are shaped to correspond with thedrive pin apertures 1072 of thedrive members 720 a,b. In addition, thedistal link 1074 includes abridge portion 1080 interconnecting thewings 1076 a,b, and thebridge portion 1080 includes aninterior pivot surface 1082 configured to engage and pivot on the upperdistal face 1044 of the extension member 1032 (of the base 806). Here, thepivot surface 1082 includes a curvature that corresponds with the curvature of the upperdistal face 1044. - When assembled, the drive pins 1060 a,b couple the
drive members 720 a,b to thedistal link 1074. For example, thedrive members 720 a,b extend distally in theslots 802 a,b along thelower surfaces coupling portion 1052 of thearticulation member 808, with the lower portions of the drive pins 1060 a,b extending upward into theapertures 1072 in thedrive members 720 a,b. Also, thedistal link 1074 is arranged in therecess 1042 of thebase 806, with thebridge portion 1080 disposed on the slidingsurface 1042 and thepivot surface 1082 abutting the upperdistal face 1044, such that the pin ends 1064 a,b of the drive pins 1060 a,b extend upward through theapertures 1078 of thedistal link 1074. Translation of thedrive members 720 a,b pushes and pulls on the drive pins 1060 a,b of thearticulation member 808, thereby rotating thearticulation member 808 about the articulation axis A3. Thus, thearticulation member 808 may be rotated about the articulation axis A3, which thereby articulates thewrist 406, via activation of thedrivers 610 b,c (FIG. 6 ) that engage thedrive inputs 608 b,c (FIG. 6 ). - Referring again to
FIGS. 7A and 7B , asixth drive shaft 702 f is coupled to thesixth drive input 608 f (FIG. 6 ) such that actuation and rotation of thesixth drive input 608 f correspondingly rotates thesixth drive shaft 702 f. Rotating thesixth drive shaft 702 f may advance and retract a firing rod (not shown) that extends through theshaft 402 to the end effector 404 (FIG. 4 ). The distal end of the firing rod is operatively coupled to the cutting element (knife) such that axial movement of the firing rod correspondingly moves the cutting element distally or proximally to transect tissue grasped between thejaws 410, 412 (FIG. 4 ). In some embodiments, distal movement of the firing rod also deploys the staples, as described above. - A
spur gear 730 is coupled to thesixth drive shaft 702 f such that rotation of thesixth drive shaft 702 f correspondingly rotates thespur gear 730. Thespur gear 730 intermeshes with asecond spur gear 732, which is attached to a firsttransfer drive shaft 734. A third spur gear (not visible) is coupled to the firsttransfer drive shaft 734 and intermeshes with afourth spur gear 736, which is attached to a secondtransfer drive shaft 738. Finally, an output pinion gear 740 (FIG. 7A ) is coupled to the secondtransfer drive shaft 738 and intermeshes with arack gear 742 of a firingmember 744 such that rotation of theoutput pinion gear 740 causes axial translation of the firingmember 744. The firingmember 744 may be coupled to the firing rod (not shown) discussed above. Accordingly, rotation of thesixth drive shaft 702 f will drive the firingmember 744 in axial translation, which correspondingly drives the firing rod in the same direction to advance and retract the cutting element at the end effector 404 (FIG. 4 ). - As described above, the tool driver 604 (
FIG. 6 ) includes one or more drivers 610 a-f (FIG. 6 ) configured to actuate corresponding drive inputs 608 a-f (FIG. 6 ), and each driver 610 a-f may be powered by a corresponding motor 616 (FIG. 6 ). Mating engagement between the drivers 610 a-f and the corresponding drive inputs 608 a-f allow the drivers 610 a-f to be activated to impart rotation to the corresponding drive shafts 702 a-f extending from the drive inputs 608 a-f. As mentioned, thewrist 406 is articulated by driving the second andthird drive inputs 608 b,c, which may be individually driven, one at a time, via the second andthird drivers 610 b,c. To increase available torque, however, thedrive inputs 608 b,c may be antagonistically driven by bothdrivers 610 b,c at the same time. - While controlling articulation of the
wrist 406 with thedrivers 610 b,c increases potential torque to accomplish a desired articulation of thewrist 406, simultaneously operating thedrivers 610 b,c presents potential for over-constrained mechanisms, thereby impairing operation of thesurgical tool 400. Thus, the roboticsurgical system 100 may include the computer system 600 (FIG. 6 ) configured to control and synchronize operation of thedrivers 610 b,c (or any two or more of the drivers 610 a-f ofFIG. 6 ) such that they operate as a single input (i.e., function as a single driver) more efficiently. This may help prevent over-constraining drive components coupled thereto, such as thedrive inputs 608 b,c (FIG. 6 ), thedrive shafts 702 b,c (FIGS. 7A-7B ), the articulation yokes 716 a,b (FIGS. 7A-7B ), etc. -
FIGS. 11A-11C illustrate various example algorithms programmable into the computer system 600 ofFIG. 6 to control operation of the second andthird drivers 610 b,c (FIG. 6 ), according to various embodiments of the present disclosure. Each algorithm identifies and operates a “master motor,” corresponding to one of thedrivers 610 b,c, and a “slave motor,” corresponding to the other of thedrivers 610 b,c. As discussed above, the second andthird drivers 610 b,c are operatively coupled to thedrive inputs 608 b,c (FIG. 6 ) to cause rotation of thecorresponding drive shafts 702 b,c. The algorithms described herein may comprise software code instructions programmed into the computer system 600 to help prevent mechanical binding of the internal drive mechanisms within thedrive housing 408 that are coupled to thedrivers 610 b,c. - It should be noted that while the example algorithms are described herein with respect to operation of the
drivers 610 b,c to cause rotation of thedrive shafts 702 b,c, one or more of the algorithms may be utilized with respect to any other of the drivers 610 a-f (FIG. 6 ). For example, one or more of the algorithms may alternatively (or in addition thereto) be configured to control the fifth andsixth drivers 610 e,f operatively coupled to the fifth andsixth drive shafts 702 e,d to cause clamping of thejaws 410, 412 (FIG. 4 ). - In
FIG. 11A , afirst algorithm 1100 a may be configured to control the position of the “master motor” using feedback to achieve a device target set by theclinician 112 a. More specifically, thefirst algorithm 1100 a may be configured to directly control the slave current based on the master current. Here, the target slave current is equal to the actual master current output to the “master motor.” In the illustrated example, thesecond driver 610 b is designated as the “master motor” and thethird driver 610 c is designated as the “slave motor.” Theclinician 112 a may pinch or manipulate theuser input device 203 to effect articulation of thewrist 406 into a desired orientation or wrist angle. Thus, the clinician 112 inputs a desired orientation or wrist angle for thewrist 406 into the computer system 600 (FIG. 6 ) via manipulation of theuser input device 203. Similarly, theclinician 112 a may pinch or manipulate theuser input device 203 to effect movement of either or both of thejaws 410, 412 (FIG. 4 ) into a desired orientation or closure angle, and thereby input a desired orientation or closure angle for thejaws computer system 606. By applying thealgorithm 1100 a, thecomputer system 606 then converts the desired orientation or wrist agle of the wrist 406 (and/or the desired orientation or closure angle of thejaws effector 404 position target, etc.) into a master motor position target using a formula for the mechanism moving or positioning the wrist 406 (and/or thejaws -
- In these formulae, the “pinRadius” is the distance between a central axis of the pivot shaft 1034 (of the base 806) and the central axis of one of the
pins wrist 406 articulates, wherein “gearRadius” is the radius of thesecond pinion gear compound pinion gear spur gear idler assembly first pinion gear - Via the
algorithm 1100 a, the computer system 606 (FIG. 6 ) may continuously monitor the actual position (e.g., angular position) of the “master motor” relative to the master motor position target, and then subtracts a master motor actual position from the master motor target position to yield a master position error. Based on thealgorithm 1100 a, thecomputer system 606 may then supply voltage to the “master motor” through a master or primary control loop depending on the master position error, a change in the master position error, and/or an accumulation of the master position error over time. Meanwhile, the master position error of the master control loop is fed to a secondary or slave control loop for the “slave motor.” - In some embodiments, the
algorithm 1100 a may utilize a lookup table to convert the master position error into a slave motor target current, and a feedback controller of the slave control loop monitors a slave motor actual current and modulates voltage supplied to the “slave motor” to achieve the slave motor target current. In doing so, the “master motor” works to achieve the target motor position (corresponding with the desired orientation or wrist angle of thewrist 406 and/or desired closure angle of thejaws 410, 412), with the “slave motor” operating in concert by helping push or pull internal drive components in the same direction as urged by the “master motor” rather than acting against or pushing such internal drive components in an opposite direction from that urged by the “master motor.” For example, as thesecond driver 610 b causes rotation of thedrive shaft 702 b to distally translate thefirst drive member 720 a and thereby articulate thewrist 406, thethird driver 610 c will assist achieving such desired articulation by causing thethird drive shaft 702 c to rotate and thereby move thesecond drive member 720 b proximally. Thus, both thedrivers 610 b,c may work in concert to complementarily cause articulation of the wrist 406 (i.e., protagonistically), rather than just one of thedrivers 610 b,c operating independently with one of thedrivers 610 b,c possibly off-setting the force output by the other (i.e., antagonistically). -
FIG. 11B is a schematic diagram of anotheralgorithm 1100 b that may be programmed into thecomputer system 606 ofFIG. 6 . Thesecond algorithm 1100 b may be configured to control the slave current based on a proportion of the master current. Here, the target slave current is equal to a proportion of the actual master current output to the “master motor.” -
FIG. 11C is a schematic diagram of athird algorithm 1100 c that may be programmed into thecomputer system 606 ofFIG. 6 . Thethird algorithm 1100 c may be configured to control the slave current based on both a proportion of the master current and direction changes sensed in the “master motor.” More specifically, the “master motor” direction changes are sensed as the master current changes between a positive or negative values (and vice versa), and each such direction change generates a decaying current spike that is added to the proportion of the actual master current output to the “master motor.” Using exponentially decaying current spikes generated after each direction change of the “master motor,” in addition to the proportional master current, helps the “slave motor” catch up to the “master motor.” - As described herein, the drivers 610 a-f of
FIG. 6 are configured to mate with corresponding drive inputs 608 a-f (FIG. 6 ) to cause rotation of associated drive shafts 702 a-f (FIGS. 7A-7B ) connected thereto, which results in various movements of the end effector 404 (FIG. 4 ) and/or the wrist 406 (FIG. 4 ). Each drive input 608 a-f may have a neutral or unarticulated position where they do not impart a corresponding movement to theend effector 404 and/or thewrist 406, but the drive inputs 608 a-f can sometimes be moved from the neutral position before thetool 400 is coupled to the tool driver 604 (FIG. 6 ). In some cases, for example, the drive inputs 608 a-f may have been previously actuated out of their neutral positions to cause movement in theend effector 404 and/or thewrist 406 during prior use. In other cases, or in addition thereto, one or more of the drive inputs 608 a-f may be rotated out of their neutral positions during sterilization or cleaning. - However, it is important to be able to quickly and accurately return the drive inputs 608 a-f to the neutral positions during or prior to use. In order to ensure that the drivers 610 a-f do not command the drive inputs 608 a-f to positions that may cause damage to the
surgical tool 400, systems may be provided for accurately “homing” thesurgical tool 400 or one or more sub-systems of thesurgical tool 400. For example, the drive inputs 608 a-f may have home positions corresponding with known positions of theend effector 404 and/or thewrist 406, and homing thesurgical tool 400 may relate the angular position of the drivers 610 a-f and, by extension the drive inputs 608 a-f coupled thereto, to the known positions of theend effector 404 and/or thewrist 406. Not only may this relationship be utilized to inhibit over-actuation (or over-rotation) of the drive inputs 608 a-f that may otherwise cause damage to thesurgical tool 400, but this relationship may be utilized to establish the actual position theend effector 404 and/or thewrist 406 in space. - Conventional homing systems often utilize mechanical limit switches and closely monitor torque output by the drivers 610 a-f to find the home position for the drive inputs 608 a-f. To do this however, the drivers 610 a-f must be rotated slowly so as to be able to detect torque spikes prior to hitting a hard stop and potentially breaking components associated with the limit switches. This can add a significant amount of time to a homing sequence, especially when utilizing surgical tools having high gear ratios.
- According to embodiments of the present disclosure, the robotic surgical system 100 (
FIG. 1 ) may include a homing system configured to quickly return (or home) the drive inputs 608 a-f to their neutral positions. The surgical tool 400 (FIG. 4 ) may be manufactured to be installed on the sterile barrier of the robotic manipulator so that the rotational position of the drive inputs 608 a-f are known. For example, the drive inputs 608 a-f may each be keyed to couple to their corresponding driver 610 a-f when in a certain rotational position. This permits the homing system to identify the relative rotational (angular) position of the drive inputs 608 a-f when thesurgical tool 400 is coupled to the tool driver 604 (FIG. 6 ) and associate that relative rotational position of the drive inputs 608 a-f with a specific cumulative motor position of the driver 610 a-f that is known by the homing system. - During manufacture, the
surgical tool 400 is calibrated to determine the absolute rotational value at which each of the drive inputs 608 a-f is in its home position (e.g., 180°), and these known calibrated home positions are stored in a memory of thesurgical tool 400 and accessible by thesurgical system 100 when thesurgical tool 400 is coupled to the tool driver 604 (FIG. 6 ). A window or “slow zone,” which is a range of rotational positions surrounding the known calibrated home positions at which the drive inputs 608 a-f may be in the home position (e.g., 180°±40°), may be built around the known calibrated home positions and similarly stored in a memory of the surgical tool 400 (e.g. thecomputer system 606 ofFIG. 6 ). The homing system may communicate with the rotary encoders 630 (FIG. 6 ) to determine the angular and/or rotational position of each drive input 608 a-f. When the drive inputs 608 a-f are being rotated near the corresponding “slow zones” based on the absolute motor position of the drivers 610 a-f as measured by the correspondingrotary encoders 630, the homing system may be programmed to decrease the speed at which the drivers 610 a-f rotate the drive inputs 608 a-f. -
FIG. 12 illustrates top, middle, and bottom graphs that illustrate operation of an example homing system configured to intelligently adjust the homing speed of the surgical tool 400 (FIG. 4 ) based on the rotational position of the drivers 610 a-f and/or the drive inputs 608 a-f operatively coupled thereto, according to one or more embodiments. In the illustrated example, thesurgical tool 400 was manufactured such that the home position of one of the drive inputs 608 a-f occurs at an absolute angular position of 180° and thesurgical tool 400 was calibrated to determine that the drive input 608 a-f may be rotated (clockwise or counter-clockwise) six (6) full revolutions from that home position until a limit is reached. The neutral position of the drive input 608 a-f is located at the midpoint of the total range. Positions of the sub-system before the neutral position will be negative; whereas, positions of the sub-system after the neutral position will be positive. Thesurgical tool 400 in this example has a gear ratio such that three (3) rotations of one of the drive inputs 608 a-f results in one (1) rotation of theend effector 404. This information may be stored in thesurgical tool 400, such as in the computer system 606 (FIG. 6 ) or the memory 624 (FIG. 6 ) of the internal computer 622 (FIG. 6 ). Mating thedrive housing 408 to thetool driver 604 places theinternal computer 622 in communication with thecomputer system 606. Also, a “slow zone” of 80° was designed to encompass that absolute angular position of the drive input 608 a-f, thereby providing a buffer of 40° ranging before and after the absolute angular position of 180° (e.g., 180°±40°) which may correspond with the drive input 608 a-f being in a home position, and this information was also stored in thesurgical tool 400. - In
FIG. 12 , the top graph illustrates the angular position of theend effector 404 in degrees versus the relative sub-system position in degrees. Thesurgical tool 400 in this example begins the homing procedure in the maximum six (6) full revolutions from the home position. This graph shows that the sub-system starts at the negative extreme of its position, moves towards the neutral position, and continues in that direction until reaching its positive extreme. - The middle graph in
FIG. 12 illustrates the absolute angular measurement of the rotational position of one of the drive inputs 608 a-f in degrees versus the relative sub-system position in degrees. This graph illustrates the absolute angular position of one of the drive inputs 608 a-f returning to 0° after reaching 360° because it shows the absolute position, rather than incremental position, of the drive inputs 608 a-f. This graph also illustrates the potential neutral position occurring at an absolute angular position of 180° that is keyed to a known relative sub-system position, and how the drivers 610 a-f may rotate the drive inputs 608 a-f six (6) full revolutions until the actual neutral position is reached. Moreover, this graph shows the “slow zone” of 80° built around the absolute angular position of one of the drive inputs 608 a-f, and how the “slow zones” are keyed to a known cumulative position of the driver 610 a-f. - The bottom graph in
FIG. 12 illustrates how the homing system may adjust the speed at which the drivers 610 a-f drive the drive inputs 608 a-f based on the relative sub-system position in degrees. Here, the bottom graph illustrates the drivers 610 a-f rotating the drive inputs 608 a-f at a first speed when the drive inputs 608 a-f are not rotationally oriented within the “slow zones” and then stepping down the speed to a second speed that is less than the first speed when the drive inputs 608 a-f are rotationally oriented within the “slow zones.” -
FIG. 13 illustrates an articulating joint 1300 for helping facilitate articulation of thewrist 406, according to one or more embodiments of the present disclosure. As described above, thewrist 406 may be articulated within a plane by antagonistically actuating a linkage assembly. More specifically, thewrist 406 may be rotated clockwise by pushing thefirst drive member 720 a while simultaneously pulling thesecond drive member 720 b, and thewrist 406 may be rotated counter-clockwise by pulling thefirst drive member 720 a while simultaneously pushing thesecond drive member 720 b. Accordingly, the joint 1300 may be rotated via antagonistic translation of the first andsecond drive members 720 a,b and, as previously described, thedrive members 720 a,b are actuated by operation of the second andthird drive inputs 608 b,c (FIG. 4 ), respectively, which in turn are driven by the second andthird drivers 610 b,c (FIG. 4 ), respectively. - During a surgical procedure, however, the
end effector 404 and thewrist 406 may be disposed within a body cavity and potentially abutting patient tissue. In such cases, the articulating joint 1300 may potentially need to move adjacent tissue. Thus, to move thewrist 406 into a desired orientation, the roboticsurgical system 100 may be configured such that the second andthird drivers 610 b,c (FIG. 4 ) cause thedrive members 720 a,b to translate with force sufficient to overcome any external load applied by tissue during a procedure, and to hold or maintain that desired orientation even when subjected to such an external load. -
FIG. 14 is a schematic diagram of anexample control scheme 1400 that may be used to control articulation of thewrist 406 via the joint 1300 ofFIG. 13 , according to one or more embodiments. In the illustrated example, thecontrol scheme 1400 utilizes an algorithm that allows for smooth and continuous articulation of the articulation joint 1300, locks the articulation joint 1300 so that it is cannot be moved by an external load, and actively works against any external load as the articulation joint 1300 is being articulated into a desired angle. - In the illustrated example, the
control scheme 1400 begins at astarting point 1402. Thecontrol scheme 1400 first determines whether the mechanism articulating the joint 1300 is properly homed, as atnode 1404. If the joint 1300 is not properly homed, thecontrol scheme 1400 initiates a homing sequence or homing process, as at 1406. During the homing process of 1406, the joint 1300 is homed by eliminating any slack in the joint 1300 mechanism by antagonistically articulating (i.e., pulling and pushing, respectively) thedrive members 720 a,b equally to a prescribed torque or current for thecorresponding driver 610 b,c; articulating the joint 1300 (clockwise or counter-clockwise) and recording the angle limits to find the home positions for bothdrivers 610 b,c; and articulating the joint 1300 to where thedrivers 610 b,c are in their home positions with thedrive members 720 a,b being under tension and compression, respectively. - If the joint 1300 is properly homed, the
clinician 112 a can direct or command the robot to articulate the joint 1300 to a desired articulation angle. More specifically, if thecontrol scheme 1400 determines that the mechanism of the joint 1300 is properly homed, an articulation command input may be provided to thecontrol scheme 1400, as at 1408. The articulation command input may be indicative of the articulation angle of the joint 1300 desired by theclinician 112 a. Thecontrol scheme 1400 proceeds by comparing a new articulation command of the joint 1300 (i.e., “newArticulationAngleCommand”) to an old articulation command of the joint 1300 (i.e., “oldArticulationCommand”, as at 1410. Here, thecontrol scheme 1400 may determine whether the new articulation command of the joint 1300 is less than, greater than, or equal to the old articulation command of the joint 1300. Depending on the relative values of the new and old articulation commands, thecontrol scheme 1400 initiates a separate articulation process, depicted herein as articulation processes 1412 a, 1412 b, and 1412 c. - Also, the relative values of the new and old articulation commands are indicative of whether the
clinician 112 a wants to move thewrist 406 or not. For example, theclinician 112 a may want to articulate the joint 1300 in a clockwise motion or in a counter-clockwise motion or maintain the joint 1300 in a particular position. If theclinician 112 a commands the joint 1300 to articulate thewrist 406 in a clockwise motion, thecontrol scheme 1400 initiates the first articulation process, as at 1412 a. If theclinician 112 a commands the joint 1300 to articulate thewrist 406 in a counter-clockwise motion, thecontrol scheme 1400 initiates the second articulation process, as at 1412 b. If theclinician 112 a does not command the joint 1300 to articulate thewrist 406, meaning thewrist 406 is to maintain its position, thecontrol scheme 1400 initiates the third articulation process, as at 1412 c. - In the illustrated example, the
control scheme 1400 initiates thefirst articulation process 1412 a if it determines at thedecision node 1410 that the new articulation command is less than the old articulation command, meaning that the joint 1300 is to move clockwise. Here, thefirst articulation process 1412 a puts thesecond driver 610 b associated with thefirst drive member 720 a in its position mode and actuates thethird driver 610 c into a commanded angle at a prescribed speed limit, and thefirst articulation process 1412 a simultaneously puts thethird driver 610 c associated with thesecond drive member 720 b in torque (or current) mode to apply a prescribed torque (or current) to thethird driver 610 c so that it pulls thesecond drive member 720 b with a constant force. - In the illustrated example, the
control scheme 1400 initiates thesecond articulation process 1412 b if it determines at thedecision node 1410 that the new articulation command is greater than the old articulation command, meaning that the joint 1300 is to move counter-clockwise. Here, thesecond articulation process 1412 b puts thesecond driver 610 b associated with thefirst drive member 720 a in torque (or current) mode to apply a prescribed torque (or current) to thesecond driver 610 b so that it pulls thefirst drive member 720 a with a constant force, and thesecond articulation process 1412 b simultaneously puts thethird driver 610 c in its position mode and actuates thethird driver 610 c into a commanded angle at a prescribed speed limit. - In the illustrated example, the
control scheme 1400 initiates thethird articulation process 1412 c if it determines at thedecision node 1410 that the new articulation command equal to the old articulation command, meaning that there is no change in articulation command is the joint 1300 is to remain stationary. Here, thethird articulation process 1412 c waits for whichever of the second orthird drivers 610 b,c that is in position mode to move into its commanded angle and then puts both the second andthird drivers 610 b,c into position mode to hold or maintain the joint 1300 at that position which corresponds with the desired articulation angle of thewrist 406. - In addition, the
third articulation process 1412 c may adjust the final commanded angles or position of one of the second orthird driver 610 b,c that follows movement of the other of the second orthird driver 610 b,c, so that the final pre-tensioning in thedrive members 720 a,b would be equal to the original pre-tensioning in thedrive members 720 a,b, as the amount of torque applied by each of thedrive members 720 a,b to the joint 1300 varies depending on the angle of the joint 1300. In particular, say thewrist 406 of the articulation sub-system is initially homed by moving the second andthird drivers 610 b,c, so that there is a certain amount of pre-tensioning in thedrive members 720 a,b, and then thesecond driver 610 b is moved in response to a new articulation command input by theclinician 112 a. As thesecond driver 610 b is moved, thereby pulling thedrive member 720 a corresponding therewith, the other motor (i.e., thethird driver 610 c) may either be disabled (i.e., goes limp) or be put in current mode with minimal current applied to it. Here, as thesecond driver 610 b is moved to achieve its final destination where the joint 1300 is moved into an angular position corresponding with the articulation command, thethird driver 610 c is put into position mode and is set to a target position, and the target position is changed as a function of the articulation command so that the tensioning of thedrive members 720 a,b would equal the amount of pre-tensioning initially applied to thedrive members 720 a,b. Thus, the angular distance between the second andthird drivers 610 b,c may change as a function of the articulation angle of the joint 1300. For example, if the second andthird drivers 610 b,c are fifty degrees (50°) apart initially to have a pre-tensioning torque of 0.1 Nm, and then the joint 1300 is articulated to an angle of ten degrees (10°), the second andthird drivers 610 b,c would be moved so that they're sixty degrees (60°) apart to have equal pre-tensioning in thedrive members 720 a,b. -
FIGS. 15A and 15B illustrate example operation of thecontrol scheme 1400 ofFIG. 14 . In particular,FIG. 15A illustrates application of thefirst articulation process 1412 a in controlling thedrivers 610 b,c to articulate the joint 1300 in a clockwise direction, andFIG. 15B illustrates application of thesecond articulation process 1412 b in controlling thedrivers 610 b,c to articulate the joint 1300 in a counter-clockwise direction. InFIG. 15A , thecontrol scheme 1400 has placed thesecond driver 610 b in position mode, where thecontrol scheme 1400 polices (monitors) motion of thesecond driver 610 b that translates thefirst drive member 720 a, and where thecontrol scheme 1400 allows thethird driver 610 c that controls thesecond drive member 720 b to pull at a limited motor torque. In addition, thecontrol scheme 1400 has placed thethird driver 610 c in torque (or current) mode where thethird driver 610 c applies constant pulling (or pushing) to force to thesecond drive member 720 b. - In
FIG. 15B , thecontrol scheme 1400 has placed thethird driver 610 c in position mode, where thecontrol scheme 1400 polices (monitors) motion of thethird driver 610 c that causes translation (movement) of thesecond drive member 720 b, and where thecontrol scheme 1400 allows thesecond driver 610 b that controls thefirst drive member 720 a to pull at a limited motor speed. In addition, thecontrol scheme 1400 has placed thesecond driver 610 b in torque (or current) mode where thesecond driver 610 b applies constant pulling (or pushing) to force to thefirst drive member 720 a. - It is often desirable to articulate the joint 1300 as quickly as possible to thereby enhance responsiveness of the surgical tool 400 (
FIG. 4 ). However, there are physical limits to the amount that the joint 1300 may articulate and, when articulating the joint 1300 at high speeds, the internal components of thesurgical tool 400 may be damaged if the joint 1300 is articulated to its limits at elevated speeds. For example, impact resulting from the joint 1300 hitting its limits at high speed may break the drive pins 1060 a,b (FIG. 10B ) of the articulation member 808 (FIGS. 9A-9B and 10A-10B ) and/or thedrive members 720 a,b. Thus, systems and methods are disclosed herein for controlling the joint 1300 and preventing it from hitting its physical limits at elevated speeds, and thereby minimizing or avoiding impact on the underlying mechanisms that articulate the joint 1300 and thewrist 406. -
FIG. 16 is a schematic diagram of an alternate example control method orscheme 1600 for quickly controlling articulation of thewrist 406 while simultaneously preventing the joint 1300 ofFIG. 13 to hit its physical limits at high speed, according to one or more embodiments. In the illustrated example, thecontrol scheme 1600 allows thedrivers 610 b,c that cause translation (motion) of thedrive members 720 a,b, and thereby articulation of the joint 1300, to move at maximum speed when an instantaneous angle of the joint 1300, which is estimated or measured based on feedback as to the position of thedrivers 610 b,c, is within defined safe limits. When the instantaneous angle of the joint 1300 is determined to be outside of the defined safe limits, thecontrol scheme 1600 slows the speed of thedrivers 610 b,c as the joint 1300 articulates at angles approaching the physical limits of the joint 1300. - The joint 1300 has a known range of articulation that defines the amount by which the
wrist 406 may angle from its unarticulated position when it extends straight along the longitudinal axis A1 of theshaft 402. For example, the joint 1300 may be configured to articulate clockwise or counter-clockwise sixty degrees (60°) relative to the longitudinal axis A1 (FIG. 4 ) before hitting its physical limits. Thus, in this example, the range of articulation of the joint 1300 would be plus or minus sixty degrees (±60°) from the longitudinal axis A1, such that the joint 1300 has a physical limit at sixty degrees (60°) in either direction from the longitudinal axis A1, and thereby providing the joint 1300 with a total of one hundred and twenty degrees (120°) of articulation. A safe limit may be defined at any point within the range of articulation. For example, a safe limit may be defined at plus or minus fifty-five degrees (±55°) from the longitudinal axis A1, such that the joint 1300 has a safety limit at fifty-five degrees (55°) in either direction from the longitudinal axis A1, and thereby providing the joint 1300 with a range of one hundred and ten degrees (110°) of articulation between the safety limits. - In this example, the
control scheme 1600 operates thedrivers 610 b,c at a first speed when the joint 1300 is articulated at an instantaneous angle ∠A less than plus or minus fifty-five degrees (∠A<±55°) from the longitudinal axis A1, and then decreases the speed of thedrivers 610 b,c when the instantaneous angle ∠A of the joint 1300 is greater than or equal to fifty-five degrees (∠A 55°). Thus, thecontrol scheme 1600 slows thedrivers 610 b,c when the instantaneous angle ∠A of the joint 1300 approaches or is near the physical limits (e.g., ±60°∠A≤±55° and speeds up thedrivers 610 b,c when the instantaneous angle ∠A of the joint 1300 is within the safety limits (e.g., ∠A is between −55° and 55°). - When the
control scheme 1600 determines that the instantaneous angle ∠A of the joint 1300 is beyond the safety limits (e.g., −60°∠A≥−55° or 55°≤∠A≤60°), thecontrol scheme 1600 slows thedrivers 610 b,c. In one example, thecontrol scheme 1600 slows thedrivers 610 b,c to a second speed that is less than the first speed at which thedrivers 610 b,c operate when the instantaneous angle ∠A of the joint 1300 is within the safety limits. In other examples, however, thecontrol scheme 1600 continuously decreases the speed of thedrivers 610 b,c as the joint 1300 approaches the physical limits, such that thecontrol method 1600 operates thedrivers 610 b,c at a range decreasing speeds when the instantaneous angle ∠A of the joint 1300 is beyond the safety limits. For example, thecontrol scheme 1600 may slow thedrivers 610 b,c when the instantaneous angle LA of the joint 1300 at the safety limit, and then further slow thedrivers 610 b,c as the instantaneous angle ∠A of the joint 1300 further approaches the physical limit. - Thus, after initializing the
control scheme 1600, as represented by astarting point 1602 inFIG. 16 , thecontrol scheme 1600 is configured to receive a commanded articulation angle indicative of the angle into which the joint 1300 is to be articulated, as at 1604. More specifically, thecontrol scheme 1600 includes an input from theclinician 112 a that represents the angle into which theclinician 112 a desires to move thewrist 406. Upon receiving the commanded articulation angle input via theinput 1604, thecontrol scheme 1600 initiates a process to adjust the commanded articulation angle based on a speed control algorithm, as at 1606. - Upon initialization of the process, the
control scheme 1600 receivesfeedback 1608 indicative of the position of thedrivers 610 b,c, as at 1608. Then, thecontrol scheme 1600 uses the feedback information to estimate the current angle at which the joint 1300 is articulated, as at 1610. Then, thecontrol scheme 1600 makes a determination as to whether the articulation angle of the joint 1300 is close to a physical limit of the joint 1300, as at 1612. If the articulation angle of the joint 1300 is not close to, or within a range preceding a limit, thecontrol scheme 1600 initiates an instruction to not change the commanded articulation angle (i.e., to maintain commanded articulation angle) of the joint 1300, as at 1614. Thecontrol scheme 1600 may end at this point, as represented by a stoppingpoint 1616. Various other systems or control schemes may be initiated after thestopping point 1616. For example, the stoppingpoint 1616 of thecontrol scheme 1600 may correspond with thestarting point 1402 of thecontrol scheme 1400 detailed above. Thus, roboticsurgical system 100 may be configured to run thecontrol scheme 1600 and thecontrol scheme 1400 in succession. - If the articulation angle of the joint 1300 is close to (or within a range preceding a limit), the
control scheme 1600 initiates an instruction causing the joint 1300 to move at a prescribed or allowable speed before reaching the stoppingpoint 1616, as at 1618. Thus, the instruction will cause thedrivers 610 b,c to rapidly move the joint 1300 into the desired articulation angle or to the physical limit of the joint 1300 to the extent that the desired articulation angle is within the permissible range of motion of the joint 1300. In the illustrated example, the instruction at 1618 continuously compares the current commanded articulation angle to the previous commanded articulation angle to determine when motor positions of thedrivers 610 b,c are nearing the physical limits of the joint 1300. The instruction may calculate the allowable speed(s) at which thedrivers 610 b,c operate to articulate the joint 1300 based on how close the joint 1300 is to its physical limits, or based on where the joint 1300 is within a safe zone immediately preceding a physical limit of the joint 1300. - The
control scheme 1600 may be configured to vary the speed of the motors 130 a,b as the joint 1300 articulates between its physical limits based on the proximity of the joint 1300 to its physical limits. For example, the instruction at 1618 may scale the speed of thedrivers 610 b,c (e.g., linearly or non-linearly) from a maximum speed to a minimum speed as the joint 1300 approaches a physical limit. In one example, the instruction commands thedrivers 610 b,c to operate at a command speed equal to the difference between the current commanded articulation angle and the previous commanded articulation angle, divided by the time step between those two measurements (i.e., CommandSpeed (CurrentCommandedArticulationAngle−PreviousCommandedArticulationAngle)/TimeStep). If the command speed is less than the allowable speed calculated by thecontrol scheme 1600, then theinstruction 1618 need not change the commanded articulation angle. But, if the command speed is greater than or equal to the allowable speed calculated by thecontrol scheme 1600, then theinstruction 1618 changes the commanded articulation angle so that the command speed would equal the allowable speed. - The robotic
surgical system 100 ofFIG. 1 may be configured to cause the surgical tool 400 (FIG. 4 ) to accurately respond as directed by theclinician 112 a (FIG. 1 ). However, various conditions may exist (or come into existence during use) that impair or inhibit thesurgical tool 400 from accurately responding to input from theclinician 112 a. For example, accuracy of thesurgical tool 400 may be affected by conditions such as mechanical wear, frictional changes, user abuse, service damage, etc., and these conditions may change during use. To ensure operation of thesurgical tool 400 correlates to commands input by theclinician 112 a (i.e., positional accuracy), the roboticsurgical system 100 may include a robust error detection system to compensate for various conditions that may change during use of thesurgical tool 400. Such error detection systems may be useful for ensuring accuracy of various functions of thesurgical tool 400, including homing sequences, articulation of thewrist 406, closure and/or grasping of thejaws surgical tool 400 by detecting errors in position of thesurgical tool 400 based on positional values recorded on thesurgical tool 400 during manufacture. - In some embodiments, the
surgical tool 400 may include physical features (or stops) that limit the various motions of the end effector 404 (FIG. 4 ) and/or the wrist 406 (FIG. 4 ) to a predefined range of motion. These features may be set or calibrated into thesurgical tool 400 during its manufacture to correspond to various movements or positions of theend effector 404 and/or thewrist 406. For example, the features may be set during manufacture to correlate to a fully advanced position of theend effector 404, a fully articulated position of thewrist 406, a home position of thewrist 406, or any other desired position. - As mentioned above, the
surgical tool 400 may include an internal computer 622 (FIG. 4 ) that may include a memory 624 (FIG. 4 ), and the position at which the physical features are set may be stored in the memory 624 and utilized as a target to determine whether it is operating accurately. For example, thesurgical tool 400 may be calibrated during manufacture to determine how many rotations of a given drive input 608 a-f (FIG. 6 ) is needed to move theend effector 404 and/or thewrist 406 into a desired position and to determine the specific angle at which the drive inputs 608 a-f are oriented when in the desired position, and this information may be stored in the memory 624. In addition, eachsurgical tool 400 may be calibrated during its manufacture to measure the torque assumed on the drive inputs 608 a-f as they are fully rotated from the home position in each direction, and this torque information may be recorded in the memory 624. Also, where two or more of the drive inputs 608 a-f are utilized to move theend effector 404 and/or thewrist 406, the relative position of the drive inputs 608 a-f may be recorded in the memory 624. With any or all of this information stored in the memory, the accuracy control system may provide feed specific to the particularsurgical tool 400 that is engaged in the robotic manipulator. - In various examples, the accuracy control system may be utilized for homing one or more of the drive inputs 608 a-f (
FIG. 6 ). In examples where two or more of the drive inputs 608 a-f are actuated to cause a particular movement of the surgical tool 400 (FIG. 4 ), the actual angular position of the drive inputs 608 a-f when in the home position and the relative position of (i.e., the angular difference between) the drive inputs 608 a-f when in the home position are stored in the onboard memory 624 (FIG. 6 ) of thesurgical tool 400 during manufacture. Then, when thesurgical tool 400 is installed on the robotic manipulator, the accuracy control system reads the position of one of the drive inputs 608 a-f as it rotates in the “home” direction, simultaneously calculating the position of the associated drive input(s) 608 a-f via the relative position data stored in the memory 624, until all of the associated drive inputs 608 a-f reach, within some error, the position recorded in the memory. - In examples where just one of the drive inputs 608 a-f is used to cause a particular movement of the
surgical tool 400, the home position of the particular one of the drive inputs 608 a-f is stored in the memory 624 (FIG. 6 ) and the accuracy control system may determine whether the particular drive input 608 a-f is in the “home position” as the corresponding driver 610 a-f (FIG. 6 ) rotates it in the “home” direction by comparing the actual angular position the drive input 608 a-f to the “home” position stored in the memory when thesurgical tool 400 is mounted in the robotic manipulator. In these examples, if the particular driver 610 a-f rotates the corresponding drive input 608 a-f less than 360°, the accuracy control system may establish the home position of the drive input 608 a-f when thesurgical tool 400 is installed on the robotic manipulator. In some examples, if the travel of any of the drive inputs 608 a-f is greater than 360°, the “home” position recorded in the memory 624 could be utilized as a confirmation check in combination with other homing control schemes as described herein. Thus, the accuracy control system may check whether the drive inputs 608 a-f are in their home position(s) based on information stored in the onboard memory 624. - In some examples, the accuracy control system may be expanded to cross-check other non-home positions of the drive inputs 608 a-f. For example, the accuracy control system may be utilized for accurately rotating one or more of the drive inputs 608 a-f (
FIG. 6 ) to effectuate a desired movement or position of the surgical tool 400 (FIG. 4 ) by comparing the actual or instantaneous position of thesurgical tool 400 achieved during operation to a set value stored in the memory 624 (FIG. 6 ). In these examples, thesurgical tool 400 is calibrated during manufacture, with the position of the end effector 404 (FIG. 4 ) and/or the wrist 406 (FIG. 4 ) being correlated with the position of the various drive inputs 608 a-f and the torque applied thereto via the corresponding drivers 610 a-f (FIG. 6 ), and such calibration information is stored in the memory 624 of thesurgical tool 400. For example, rotational positions and/or torques of any of the drive inputs 608 a-f corresponding with a fully advanced position of the end effector 404 (e.g., fully expandedjaws 410, 412), fully angled position of thewrist 406, and/or a home position of theend effector 404 and/or thewrist 406, etc. may be recorded in the memory 624. This stored information provides a target that is specific or unique to the particularsurgical tool 400 installed in the robotic manipulator. If the robotic surgical system 100 (FIG. 1 ) drives one or more of the drivers 610 a-f to a particular position and the actually achieved position of theend effector 404 and/or thewrist 406 of thesurgical tool 400 does not correlate with the position information stored in the memory 624, the accuracy control system will report an error in position. - In some examples, the accuracy control system is incorporated with two or more of the drive inputs 608 a-f (
FIG. 6 ). For example, the accuracy control system may be utilized with thedrive inputs 608 b,c that control the wrist 406 (FIG. 4 ) and/or with thedrive inputs 608 d,e that control thejaws 410, 412 (FIG. 4 ). In these examples, during manufacture of thesurgical tool 400 the absolute angular positions of two or more of the drive inputs 608 a-f when thesurgical tool 400 is at a set desired position (i.e., the desired position of theend effector 404 and/or the wrist 406) are read and stored in the memory 624 (FIG. 6 ), and also the relative angular position between the drive inputs 608 a-f corresponding with the set position of the surgical tool 400 (i.e., the angular difference between the drive inputs 608 a-f) is recorded in the memory 624. The absolute angle of the drive inputs 608 a-f corresponds to a globally consistent angle that is consistent over time and over robot-power cycles. For example, a graphical arrow may be provided on the drive input 608 a-f such that it may be determined that, when such graphical arrow is aligned with a corresponding graphical arrow on thetool driver 604 of the robot, the angle of the drive input 608 a-f is “absolute zero.” When thesurgical tool 400 is installed in a robotic manipulator and theclinician 112 a inputs a command to move thesurgical tool 400 to a desired position, if the actual position of the drive inputs 608 a-f corresponding with the clinician's 112 a desired movement does not match the positional information stored in the memory 624, the accuracy control system would report an error. - In other examples, the accuracy control system is incorporated with just one of the drive inputs 608 a-f. In these examples, the absolute position of one of the drive inputs 608 a-f corresponding with a set desired position of the
surgical tool 400 would be stored in its memory 624 during manufacture or calibration and, during use, the accuracy control system could check whether thesurgical tool 400 is in the desired position. - In some examples, the accuracy control system may be configured to detect a closure error of the
jaws 410, 412 (FIG. 4 ) where the actual positions of the drive inputs 608 a-f (FIG. 6 ) corresponding with thejaws jaws jaws jaws jaws surgical tool 400 and, if they change by a specified amount (or more), the accuracy control system may be configured report a wear error. - The robotic surgical system 100 (
FIG. 1 ) may further include or incorporate a control scheme that moves thedrive members 720 a,b synchronously, meaning that, thesecond driver 610 b (FIG. 6 ) of the tool driver 604 (FIG. 6 ) causes translation of thefirst drive member 720 a and thethird driver 610 c causes an equal and opposite translation of thesecond drive member 720 b. For example, a left-hand articulation of the wrist 406 (FIG. 4 ) is accomplished by moving thefirst drive member 720 a proximally a distance “x” while moving thesecond drive member 720 b distally a distance “−x”. The roboticsurgical system 100 commands thedrivers 610 b,c (that engage thedrive inputs 608 b,c) to rotate into motor positions necessary to cause translation of thedrive members 720 a,b distances of “x” and “−x”, respectively. Thus, driver position commands R3 and R4 may be calculated to synchronously translate thedrive members 720 a,b based on an input from theclinician 112 a (i.e., articulationAngleCommanded). The driver position commands R3, R4 may be calculated using the following equations: -
- This control scheme translates input from the
clinician 112 a (i.e., articulationAngleCommanded) into rotation of thedrivers 610 b,c. In this control scheme, the values “x” and “−x” are not directly calculated, as the input from theclinician 112 a is the desired angle to move thewrist 406 and, from that input, the control scheme outputs the rotary input or control of thedriver 610 b,c (i.e., the driver position commands R3, R4). To calculate “x”, the formula would be x=R3*GearRatio*2*π*gearRadius, and “−x” may be similarly calculated. The forgoing formulae include mathematical representations of the psychical components of thesurgical tool 400, where pinRadius is the distance from the center of thepivot shaft 1034 to the center of the drive pins 1060 a,1060 b, GearRatio is the ratio created from thespur gear 709 a,b through theidler assembly 715 a,b (i.e., the compound gear) to thecompound pinion gear 710 a,b, and gearRadius is the radius of thesecond pinion gear 713 a,b (of thecompound pinion gear 710 a,b) that interacts with thedrive rack 712 a,b. - This synchronous control scheme, however, may not accurately articulate the
wrist 406 into the desired articulation angle commanded by theclinician 112 a. For example, friction resulting from wear may cause thewrist 406 to articulate only 40° degrees despite theclinician 112 a having input a desired articulation angle of 45°. In addition to decreasing accuracy of articulation, this synchronous control scheme may incur decreased mechanical advantage as thewrist 406 articulates at increasing angles over time. - Thus, the robotic
surgical system 100 may include improved control schemes configured to enhance articulation of thewrist 406. In some examples, the roboticsurgical system 100 includes a differential control scheme for controlling movement of thedrive members 720 a,b to more accurately articulate thewrist 406 into the desired wrist position input by theclinician 112 a. In various examples, the differential control scheme may also increase the maximum angles to which thewrist 406 may articulate and increase the mechanical advantage of the wrist 406 (i.e., the force at which it may articulate). - The differential control scheme is a passive control that calculates the driver position commands R3, R4 by which the
drive members 720 a,b are moved utilizing the formulae described above and modified by a constant α or a mathematical function. For example, the differential control scheme accomplishes a left-hand articulation of thewrist 406 by moving thefirst drive member 720 a a distance “x” via the first motor command R3 while moving thesecond drive member 720 b a distance “−x-α” via the second motor command R4. Thus, one side of the articulation system may move more (or less) than the other side. In this example described, if the geometry were perfect and there were no friction the constant α would increase the tension in the system. If the constant α is a constant then the increase in tension would be applied only when the articulationAngleCammanded is greater (or lesser) than 0. However, the constant α may be described as increasing or decreasing as a function of the articulationAngleCommanded, and, as described below, the constant α may be an empirically determined value and/or based on a mathematical function. - In some examples, the constant α may be empirically determined. In these examples, the constant α may be empirically determined during testing, manufacture, and/or calibration of the
surgical tool 400 and, therefore, the constant α may be unique to eachsurgical tool 400. Here, the constant α may act as a correction factor for the gear/linkage mechanism controlling thewrist 406, between a nominal condition and an actual condition for which friction and wear (e.g., stretch of thedrive members 720 a,b) is accounted. In one example, each of thesurgical tools 400 during manufacture is placed in a testing apparatus that senses articulation angle of thewrist 406 while rotating thedrive inputs 608 b,c. The value of the constant α may be adjusted to minimize error between the actual measured articulation angle of thewrist 406 and the expected articulation angle of thewrist 406, and then the value of the constant α may be saved on the memory of thesurgical tool 400 to be utilized by the roboticsurgical system 100 during an operation. When the actual measured articulation angle of thewrist 406 is minimized, the value of the constant α would be flashed to thesurgical tool 400 so that the roboticsurgical system 100 may use it. - In other examples, the constant α may be a value that is modified by a function. In these examples, the constant α may be assigned a value or a value may be empirically determined as described above. Regardless, the constant α may be modified by various functions of the desired angle input by the
clinician 112 a (i.e., articulationAngleCommanded), such as linear functions, sinusoidal functions, exponential functions, polynomial functions, or any combination thereof. Thus, driver position commands R3, R4 are calculated to translate thedrive members 720 a,b a distance (i.e., “x” or “−x”) based on input from theclinician 112 a (i.e., articulationAngleCommanded) minus a correction factor, where the correction factor deducted from the distance is a function of the articulationAngleCommanded multiplied by the constant α. - In one example, the correction factor is a sinusoidal function modifying the constant α. Here, the constant α is a value multiplied by the sin of the desired angle input by the
clinician 112 a (i.e., articulationAngleCommanded), such that the driver position commands R3, R4 are calculated with the following equations. - If articulationAngleCommanded is >0:
-
- If articulationAngleCommanded is <0:
-
- In another example, the correction factor is a linear function of the constant α. Here, the constant α is a value multiplied by a linear factor m (i.e., the slope) multiplied by the desired angle input by the
clinician 112 a (i.e., articulationAngleCommanded) plus b (i.e., the intercept), such that the driver position commands R3, R4 are calculated with the following equations. - If articulationAngleCommanded is >0:
-
- If articulationAngleCommanded is <0:
-
- In other examples, the correction factor is a polynomial function of the constant α. For example, a polynomial function (where a, b, and c are constants) could be as follows.
- If articulationAngleCommanded is >0:
-
- If articulationAngleCommanded is <0:
-
- In other examples, the correction factor is an exponential function of the constant α. For example, an exponential function (where e is a constant) could be as follows.
- If articulationAngleCommanded is >0:
-
- If articulationAngleCommanded is <0:
-
-
FIGS. 17A and 17B are graphical representations illustrating the actual angular position output versus the desired angular input for each of thedrive inputs 608 b,c (FIG. 6 ) utilizing the foregoing equations, according to one or more embodiments. In particular,FIG. 17A plots the actual angular position obtained for thesecond drive input 608 b for each desired angular position input by theclinician 112 a (i.e., articulationAngleCommanded) under the current control scheme, the sinusoidal control scheme, and the linear control scheme. Similarly,FIG. 17B plots the actual angular position obtained for thethird drive input 608 c for each desired angular position input by theclinician 112 a (i.e., articulationAngleCommanded) under the current control scheme, the sinusoidal control scheme, and the linear control scheme. Thus, as theend effector 404 moves to the right (from center) the angular displacement of the right drive input increases at a greater rate than the left drive input, and when theend effector 404 moves to the left (from center) the angular displacement of the left drive input increases at a greater rate than the right drive input. - The surgical tool 400 (
FIG. 4 ) described and illustrated herein is configured as a “rotary surgical tool” because it includes rotary drive inputs 608 a-f (FIG. 6 ) that are each rotated by a corresponding driver 610 a-f (FIG. 6 ) on the robotic manipulator. In other examples, however, thesurgical tool 400 may be differently configured such that it may be actuated by drivers configured to impart different types of mechanical energy. For example, thesurgical tool 400 may be configured as a linear drive tool having one or more linear drive inputs as described in U.S. Patent Application Publication No. 2018/0168745, the contents of which are hereby incorporated by reference. In some examples, thesurgical tool 400 may include a combination of both rotary and linear drive inputs. - In some embodiments, the robotic surgical system 100 (
FIG. 1 ) may include a closure control system configured to optimize the closure stroke of the closure tube 722 (FIGS. 7A-7B and 8A-8B ). The closure control system may monitor the stroke distance and the force applied to theclosure tube 722 during closure of thejaws closure tube 722 has translated too far (i.e., over travel) along longitudinal axis A1 (FIGS. 4, 6, and 7A-7B ). Thus, the closure control system may limit actuation of the drive inputs (e.g., the fourth andfifth drive inputs 608 d,e ofFIG. 6 ) to translate theclosure tube 722 the minimum stroke distance required to close thejaws surgical tool 400 by limiting application of high forces as needed. For example, increased force will typically be applied to theclosure tube 722 when manipulating thicker tissue; whereas, lesser amounts of force will be applied when manipulating tissue having less thickness. In addition, theclosure tube 722 will not be subjected to an over-closure event during closure of thejaws closure tube 722 as the mechanism is less sensitive to mechanical variation and/or tolerance. Thus, instead of the mechanism translating theclosure tube 722 to the maximum possible needed (depending on tissue variation and/or mechanical variation), the mechanism need only translate the closure tube 722 a sufficient amount to achieve an inflection point. -
FIG. 18 illustrates a force-distance graph of an exemplary closure control system, according to one or more embodiments. In this example, the closure control system is configured to extend the closure tube 722 (FIGS. 7A-7B and 8A-8B ) by actuating the corresponding drivers (e.g., the fourth andfifth driver 610 d,e ofFIG. 6 ) corresponding with the appropriate drive inputs (e.g., the fourth andfifth drivers inputs 608 d,e ofFIG. 6 ). The current required to drive the drivers is recorded and equated to a force utilizing constants stored in the memory 624 (FIG. 6 ) of thesurgical tool 400. Also, the angular position of the drivers is recorded and equated to a travel amount via mechanism dependent constants stored in the memory 624. As theclosure tube 722 is being closed, the closure control system calculates the derivative of force versus distance and utilizes a low-pass filter to remove spikes in the curve that are caused by noise. Then, when the filtered force versus distance derivative exceeds a mechanism-dependent threshold stored in the memory of thesurgical tool 400, the closure control system will stop further travel of theclosure tube 722 and/or other closure mechanisms, and report that thesurgical tool 400 is fully clamped. Upon receiving a report that thesurgical tool 400 is fully clamped, the robotic surgical system 100 (FIG. 1 ) may direct thesurgical tool 400 to fire and thereby transect and apply staples to the tissue clamped therein. - Embodiments disclosed herein include:
- A. A surgical tool includes a drive housing, a shaft that extends from the drive housing, a wrist arranged at an end of the shaft, and a linkage assembly actuatable to articulate the wrist in a plane and including a first drive member extending within the shaft from the drive housing and being operatively connected to the wrist, and a second drive member extending within the shaft from the drive housing and being operatively connected to the wrist. Wherein actuation of the first and second drive members in opposite axial directions within the shaft causes the wrist to articulate in the plane.
- B. A method of homing a rotatable drive input of a robotic surgical tool includes recording a home position of the drive input in a memory of the robotic surgical tool, establishing a slow zone encompassing a known angular magnitude away from the home position, and rotating the drive input toward the home position, and slowing a rotation speed of the drive input upon reaching the slow zone.
- C. A system for controlling articulation of a joint in a surgical tool driven by a robotic manipulator, the surgical tool having first and second drive members operatively coupled to the joint and arranged to translate in opposite directions when actuated by respective first and second drivers of the robotic manipulator, wherein, upon receiving a command to rotate the joint in a first rotational direction, the first driver actuates and thereby pushes the first drive member distally and, simultaneously, the second driver actuates and thereby pulls the second drive member proximally, thereby rotating the joint in the first rotational direction, wherein, upon receiving a command to rotate the joint in a second rotational direction opposite the first rotational direction, the second driver actuates and thereby pushes the second drive member distally and, simultaneously, the first driver actuates and thereby pulls the first drive member proximally, thereby rotating the joint in the second rotational direction.
- D. A system for controlling antagonistic translation of a pair of drive members in a surgical tool, the surgical tool being mountable to a robotic manipulator having a first driver operable to translate the first drive member and a second driver operable to translate the second drive member, wherein, upon receiving a desired articulation angle input, the system determines a first driver position command and a second driver position command at which the first and second drivers will cause translation of the first and second drive members, respectively, to achieve the desired articulation angle input, wherein the first driver command causes the first drive member to translate a distance in a proximal direction and the second driver command causes the second drive member to translate the distance in a distal direction, and wherein the distance is modified by a correction factor.
- Each of embodiments A, B, C, and D may have one or more of the following additional elements in any combination: Element 1: wherein the wrist includes a base and an articulation member that is rotatable relative to the base when acted upon by the first and second drive members. Element 2: wherein the base includes a pivot shaft that is disposed within an aperture of the articulation member, the pivot shaft defining an articulation axis about which the articulation member rotates. Element 3: wherein the first drive member is coupled to a first drive pin of the articulation member and the second drive member is coupled to a second drive pin of the articulation member. Element 4: wherein the linkage assembly further includes a distal link that couples distal ends of the first and second drive members at the wrist. Element 5: wherein the first drive pin of the articulation member is disposed within a first aperture of the distal link and the second drive pin of the articulation member is disposed within a second aperture of the distal link. Element 6: wherein the base is connected to an inner grounding shaft that extends proximally within the shaft. Element 7: wherein the first and second drive members are arranged within a first and second slot, respectively, defined within the inner grounding member. Element 8: wherein at least a portion of the first and second slots are defined between an upper surface of the inner grounding member and a lower surface of the base. Element 9: further comprising a first drive shaft rotatably mounted within the drive housing and operatively coupled to the first drive member such that rotation of the first drive shaft causes axial movement of the first drive member, and a second drive shaft rotatably mounted within the drive housing and operatively coupled to the second drive member such that rotation of the second drive shaft causes axial movement of the second drive member. Element 10: wherein the first drive shaft is operatively coupled to the first drive member via a first gear arrangement having a gear ratio greater than or less than 1:1, and the second drive shaft is operatively coupled to the second drive member via a second gear arrangement having a gear ratio greater than or less than 1:1. Element 11: further comprising a first articulation yolk arranged around the inner grounding shaft and operatively coupled to a proximal end of the first drive member and a second articulation yolk arranged around the inner grounding shaft and operatively coupled to a proximal end of the second drive member, wherein axial translation of the first and second articulation yolks causes axial translation of the first and second drive members, respectively. Element 12: wherein the first and second articulation yolks are arranged around the inner grounding shaft such that they rotate with the inner grounding shaft. Element 13: wherein the first drive shaft is operatively coupled to the first drive member via a first drive rack having a first yolk engageable with a first articulation yolk operatively coupled to a proximal end of the first drive member, and wherein the second drive shaft is operatively coupled to the second drive member via a second drive rack having a second yolk engageable with a second articulation yolk operatively coupled to a proximal end of the second drive member.
- Element 14: further comprising measuring a rotational position of the drive input with a rotary encoder. Element 15: further comprising detecting a torque spike with one or more torque sensors when the drive input reaches the home position.
- Element 16: wherein the first and second drivers of the robotic manipulator maintain equal tension or compression in the first and second drive members until commanded to rotate the joint in either the first or second rotational direction. Element 17: wherein the tension or compression applied by the first and second motors is dependent upon an articulation angle of the joint.
- Element 18: wherein the correction factor is an empirically determined constant of the surgical tool. Element 19: wherein the correction factor is a product of a constant and a function, and wherein the function is selected from the group consisting of a linear function, a sinusoidal function, an exponential function, a polynomial function, and any combination thereof.
- By way of non-limiting example, exemplary combinations applicable to A, B, C, and D include:
Element 1 withElement 2;Element 1 withElement 3;Element 3 with Element 4; Element 4 with Element 5;Element 1 with Element 6; Element 6 with Element 7; Element 7 with Element 8; Element 9 with Element 10; Element 7 with Element 11; Element 11 with Element 12; Element 10 with Element 13; and Element 16 with Element 17. - Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.
- As used herein, the phrase “at least one of” preceding a series of items, with the terms “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C.
Claims (20)
1. A method of homing a drive input of a robotic surgical tool, comprising:
recording and storing a home position of the drive input in a memory included in the robotic surgical tool;
establishing a slow zone for the drive input encompassing a known angular magnitude away from the home position;
storing the slow zone in the memory;
rotating the drive input toward the home position; and
slowing a rotation speed of the drive input upon reaching the slow zone.
2. The method of claim 1 , wherein rotating the drive input toward the home position includes:
mounting the robotic surgical tool to a tool driver of a robotic manipulator, the tool driver including a driver matable with the drive input, and a motor that drives the driver in rotation to thereby rotate the drive input;
sending an input signal to the motor to operate the driver and thereby rotate the drive input; and
measuring rotational motion of the motor with a rotary encoder communicably coupled to the motor and thereby determining an angular position of the drive input.
3. The method of claim 1 , further comprising detecting a torque spike with one or more torque sensors when the drive input reaches the home position.
4. The method of claim 1 , wherein recording and storing the home position of the drive input in the memory comprises:
calibrating the robotic surgical tool during manufacture of the robotic surgical tool and thereby determining an absolute angular position at which the drive input reaches the home position; and
storing the absolute angular position in the memory as the home position.
5. The method of claim 1 , wherein the drive input requires rotation of two or more full revolutions prior to reaching the home position, the method further comprising
establishing the slow zone for each full revolution of the drive input; and
slowing the rotation speed of the drive input upon reaching each slow zone.
6. The method of claim 1 , wherein slowing the rotation speed of the drive input upon reaching the slow zone comprises:
rotating the drive input at a first speed when the drive input is not rotationally oriented within the slow zone; and
rotating the drive input at second speed slower than the first speed when the drive input is rotationally oriented within each slow zone.
7. A homing system for a robotic surgical tool including a drive housing and a drive input rotatably mounted to the drive housing, the homing system comprising:
a memory included in an internal computer forming part of the drive housing, the memory having stored therein:
a home position of the drive input; and
a slow zone established for the drive input that encompasses a known angular magnitude away from the home position; and
a computer system in communication with the memory and in further communication with a motor operable to rotate the drive input and a rotary encoder operable to determine an angular position of the drive input,
wherein the computer system causes the motor to reduce a rotation speed of the drive input upon reaching the slow zone.
8. The homing system of claim 7 , further comprising one or more torque sensors operatively coupled to the motor and in communication with the computer system, wherein the one or more torque sensors detect a torque spike when the drive input reaches the home position.
9. The homing system of claim 7 , wherein the home position of the drive input is 180° and the slow zone comprises a buffer of 40° ranging before and after the absolute angular position of 180°.
10. The homing system of claim 7 , wherein the drive input requires rotation of two or more full revolutions prior to reaching the home position, and wherein the slow zone comprises a corresponding slow zone for each full revolution of the drive input.
11. The homing system of claim 10 , wherein computer system is programmed to slow the rotation speed of the drive input upon reaching each slow zone.
12. The homing system of claim 7 , wherein the drive input is rotated at a first speed when the drive input is not rotationally oriented within the slow zone, and wherein the drive input is rotated at second speed slower than the first speed when the drive input is rotationally oriented within each slow zone.
13. A robotic surgical tool, comprising
a drive housing having first and second drive inputs rotatably coupled thereto, the drive housing being mountable to a tool driver of a robotic manipulator, and the tool driver including first and second drivers matable with the first and second drive inputs;
a shaft extending from the drive housing and terminating at an end effector;
a wrist joint interposing the shaft and the end effector;
a first drive member extending from the drive housing and terminating at the wrist joint, the first drive member being operatively coupled to the first drive input such that actuation of the first driver moves the first drive member along the shaft; and
a second drive member extending from the drive housing and terminating at the wrist joint, the second drive member being operatively coupled to the second drive input such that actuation of the second driver moves the second drive member along the shaft,
wherein the wrist joint is rotated a first rotational direction by actuating the first driver and thereby pushing the first drive member distally while simultaneously actuating the second driver and thereby pulling the second drive member proximally, and
wherein the wrist joint is rotated a second rotational direction by actuating the first driver and thereby pulling the first drive member proximally while simultaneously actuating the second driver and thereby pushing the second drive member distally.
14. The robotic surgical tool of claim 13 , wherein the first and second drivers maintain equal tension or compression in the first and second drive members until commanded to rotate the wrist joint in either the first or second rotational directions.
15. The robotic surgical tool of claim 14 , wherein the tension or compression applied by the first and second drivers is dependent upon an articulation angle of the joint.
16. The robotic surgical tool of claim 13 , wherein the wrist joint includes physical limits past which the wrist joint cannot physically rotate, the homing system further comprising:
a computer system in communication with first and second motors arranged to drive the first and second drivers, respectively,
wherein the computer system is programmed to operate the first and second motors at a first speed when an instantaneous angle of the wrist joint is within a defined safe limit away from the physical limits, and
wherein the computer system is programmed to operate the first and second motors at a second speed lower than the first speed when the instantaneous angle of the wrist joint is outside the defined safe limit and near the physical limits.
17. The robotic surgical tool of claim 16 , wherein the first and second motors decelerate at a constant speed when transitioning between the first and second speeds.
18. A system for controlling antagonistic translation of a pair of drive members in a surgical tool, the surgical tool being mountable to a robotic manipulator having a first driver operable to translate the first drive member and a second driver operable to translate the second drive member,
wherein, upon receiving a desired articulation angle input, the system determines a first driver position command and a second driver position command at which the first and second drivers will cause translation of the first and second drive members, respectively, to achieve the desired articulation angle input,
wherein the first driver command causes the first drive member to translate a distance in a proximal direction and the second driver command causes the second drive member to translate the distance in a distal direction, and
wherein the distance is modified by a correction factor.
19. The system of claim 18 , wherein the correction factor is an empirically determined constant of the surgical tool.
20. The system of claim 18 , wherein the correction factor is a product of a constant and a function, and wherein the function is selected from the group consisting of a linear function, a sinusoidal function, an exponential function, a polynomial function, and any combination thereof.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US18/303,253 US20230355338A1 (en) | 2019-08-28 | 2023-04-19 | Articulating including antagonistic controls for articulation and calibration |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16/553,725 US11666404B2 (en) | 2019-08-28 | 2019-08-28 | Articulating including antagonistic controls for articulation and calibration |
US18/303,253 US20230355338A1 (en) | 2019-08-28 | 2023-04-19 | Articulating including antagonistic controls for articulation and calibration |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/553,725 Division US11666404B2 (en) | 2019-08-28 | 2019-08-28 | Articulating including antagonistic controls for articulation and calibration |
Publications (1)
Publication Number | Publication Date |
---|---|
US20230355338A1 true US20230355338A1 (en) | 2023-11-09 |
Family
ID=72193511
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/553,725 Active 2040-07-22 US11666404B2 (en) | 2019-08-28 | 2019-08-28 | Articulating including antagonistic controls for articulation and calibration |
US18/303,253 Pending US20230355338A1 (en) | 2019-08-28 | 2023-04-19 | Articulating including antagonistic controls for articulation and calibration |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/553,725 Active 2040-07-22 US11666404B2 (en) | 2019-08-28 | 2019-08-28 | Articulating including antagonistic controls for articulation and calibration |
Country Status (4)
Country | Link |
---|---|
US (2) | US11666404B2 (en) |
EP (1) | EP4021332A2 (en) |
CN (1) | CN114340543A (en) |
WO (1) | WO2021038360A2 (en) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140005640A1 (en) | 2012-06-28 | 2014-01-02 | Ethicon Endo-Surgery, Inc. | Surgical end effector jaw and electrode configurations |
US11701190B2 (en) | 2019-03-15 | 2023-07-18 | Cilag Gmbh International | Selectable variable response of shaft motion of surgical robotic systems |
US11666401B2 (en) | 2019-03-15 | 2023-06-06 | Cilag Gmbh International | Input controls for robotic surgery |
US11607278B2 (en) | 2019-06-27 | 2023-03-21 | Cilag Gmbh International | Cooperative robotic surgical systems |
US11723729B2 (en) | 2019-06-27 | 2023-08-15 | Cilag Gmbh International | Robotic surgical assembly coupling safety mechanisms |
US11612445B2 (en) | 2019-06-27 | 2023-03-28 | Cilag Gmbh International | Cooperative operation of robotic arms |
GB2597084A (en) * | 2020-07-14 | 2022-01-19 | Cmr Surgical Ltd | Geared instruments |
WO2022033693A1 (en) * | 2020-08-13 | 2022-02-17 | Abb Schweiz Ag | Method of controlling industrial actuator, control system, and industrial actuator system |
US11813746B2 (en) | 2020-12-30 | 2023-11-14 | Cilag Gmbh International | Dual driving pinion crosscheck |
EP4304509A2 (en) * | 2021-03-11 | 2024-01-17 | Covidien LP | Surgical robotic system for realignment of wristed instruments |
US20230001579A1 (en) | 2021-06-30 | 2023-01-05 | Cilag Gmbh International | Grasping work determination and indications thereof |
US11931026B2 (en) | 2021-06-30 | 2024-03-19 | Cilag Gmbh International | Staple cartridge replacement |
US20230051938A1 (en) * | 2021-08-16 | 2023-02-16 | Cilag Gmbh International | Adjustable power transmission mechanism for powered surgical stapler |
US20230404577A1 (en) | 2022-06-15 | 2023-12-21 | Cilag Gmbh International | Impact mechanism for grasp clamp fire |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8876820B2 (en) * | 2004-10-20 | 2014-11-04 | Atricure, Inc. | Surgical clamp |
US20130165945A9 (en) | 2007-08-14 | 2013-06-27 | Hansen Medical, Inc. | Methods and devices for controlling a shapeable instrument |
US9101379B2 (en) | 2010-11-12 | 2015-08-11 | Intuitive Surgical Operations, Inc. | Tension control in actuation of multi-joint medical instruments |
US9693774B2 (en) | 2014-06-25 | 2017-07-04 | Ethicon Llc | Pivotable articulation joint unlocking feature for surgical stapler |
US10405932B2 (en) | 2016-12-20 | 2019-09-10 | Ethicon Llc | Robotic endocutter drivetrain with bailout and manual opening |
US10258418B2 (en) | 2017-06-29 | 2019-04-16 | Ethicon Llc | System for controlling articulation forces |
US11026712B2 (en) | 2017-10-30 | 2021-06-08 | Cilag Gmbh International | Surgical instruments comprising a shifting mechanism |
US11020112B2 (en) * | 2017-12-19 | 2021-06-01 | Ethicon Llc | Surgical tools configured for interchangeable use with different controller interfaces |
-
2019
- 2019-08-28 US US16/553,725 patent/US11666404B2/en active Active
-
2020
- 2020-08-14 CN CN202080060509.9A patent/CN114340543A/en active Pending
- 2020-08-14 WO PCT/IB2020/057695 patent/WO2021038360A2/en unknown
- 2020-08-14 EP EP20760919.9A patent/EP4021332A2/en active Pending
-
2023
- 2023-04-19 US US18/303,253 patent/US20230355338A1/en active Pending
Also Published As
Publication number | Publication date |
---|---|
WO2021038360A3 (en) | 2021-04-22 |
EP4021332A2 (en) | 2022-07-06 |
US11666404B2 (en) | 2023-06-06 |
WO2021038360A2 (en) | 2021-03-04 |
US20210059777A1 (en) | 2021-03-04 |
CN114340543A (en) | 2022-04-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20230355338A1 (en) | Articulating including antagonistic controls for articulation and calibration | |
US11382704B2 (en) | Closure mechanism for surgical tool | |
US11793519B2 (en) | Methods and systems for detecting staple cartridge misfire or failure | |
US20230157687A1 (en) | Methods and systems for controlling staple firing | |
CN109996504B (en) | Manual release assembly for robotic surgical tool | |
CN109890315B (en) | Constant force spring assembly for robotic surgical tool | |
US20240108432A1 (en) | Manual knife bailout monitoring using inductive coupling | |
US11937892B2 (en) | Variable jaw closure of a robotic surgical system | |
US20220346891A1 (en) | Robotic surgical system with articulation lockout | |
US20220346898A1 (en) | Multi-zone jaw closure of a robotic surgical system | |
US20230338051A1 (en) | Unclamp lockout mechanism for a surgical tool | |
WO2024069559A1 (en) | Adapting tissue treatment motion parameters based on situational parameters |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STPP | Information on status: patent application and granting procedure in general |
Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION |