U.S. patent application number 10/004399 was filed with the patent office on 2002-07-11 for multi-component telepresence system and method.
This patent application is currently assigned to Intuitive Surgical, Inc.. Invention is credited to Cooper, Thomas G..
Application Number | 20020091374 10/004399 |
Document ID | / |
Family ID | 21869741 |
Filed Date | 2002-07-11 |
United States Patent
Application |
20020091374 |
Kind Code |
A1 |
Cooper, Thomas G. |
July 11, 2002 |
Multi-component telepresence system and method
Abstract
The present invention provides systems and methods for
performing robotically-assisted surgical procedures on a patient.
In particular, a three-component surgical system is provided that
includes a non-sterile drive and control component, a sterilizable
end effector or surgical tool and an intermediate connector
component that includes mechanical elements for coupling the
surgical tool with the drive and control component and for
transferring motion and electrical signals therebetween. The drive
and control component is shielded from the sterile surgical site,
the surgical tool is sterilizable and disposable and the
intermediate connector is sterilizable and reusable. In this
manner, the intermediate connector can be sterilized after a
surgical procedure without damaging the motors or electrical
connections within the drive and control component of the robotic
system.
Inventors: |
Cooper, Thomas G.; (Menlo
Park, CA) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Intuitive Surgical, Inc.
Mountain View
CA
|
Family ID: |
21869741 |
Appl. No.: |
10/004399 |
Filed: |
October 30, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10004399 |
Oct 30, 2001 |
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09406360 |
Sep 28, 1999 |
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6346072 |
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09406360 |
Sep 28, 1999 |
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08975617 |
Nov 21, 1997 |
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6132368 |
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60033321 |
Dec 12, 1996 |
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Current U.S.
Class: |
606/1 |
Current CPC
Class: |
A61B 46/13 20160201;
A61B 2034/305 20160201; A61B 34/76 20160201; A61B 2090/506
20160201; A61B 34/37 20160201; A61B 34/71 20160201; A61B 2090/0814
20160201; A61B 34/35 20160201; A61B 34/30 20160201; A61B 90/361
20160201; A61B 2090/0803 20160201; A61B 2017/00482 20130101 |
Class at
Publication: |
606/1 |
International
Class: |
A61B 017/00 |
Claims
What is claimed is:
1. A method for performing a surgical procedure with a robotic
surgical system comprising: providing a plurality of surgical
instrument assemblies each comprising a wrist unit having a shaft
with a proximal end and a distal wrist, and an instrument coupled
to the distal wrist; connecting the proximal end of the wrist unit
shaft of one of the surgical instrument assemblies to a manipulator
arm; and introducing the instrument of said one of the surgical
instrument assemblies to a treatment site on a patient with the
manipulator arm.
2. The method of claim 1 further comprising removing the instrument
of said one of the surgical instrument assemblies from the
treatment site and disconnecting the proximal end of the wrist unit
shaft of said one of the surgical instrument assemblies from the
manipulator arm.
3. The method of claim 1 further comprising connecting the proximal
end of the wrist unit shaft of another one of the surgical
instrument assemblies to the manipulator arm, and introducing the
instrument of said another one of the surgical instrument
assemblies to the treatment site with the manipulator arm.
4. The method of claim 1 further comprising pivoting the instrument
about the distal wrist of the wrist unit shaft.
5. The method of claim 1 further comprising: shielding the
manipulator arm from the treatment site with a sterile drape;
attaching a sterile adaptor to the manipulator arm through the
sterile drape; and attaching the proximal end of the wrist unit
shaft of said one of the surgical instrument assemblies to the
sterile adaptor.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of, and claims the
benefit of priority from, U.S. patent application Ser. No.
09/406,360 filed on Sep. 28, 1999; which is a continuation of U.S.
patent application Ser. No. 08/975,617 filed Nov. 21, 1997; and
which is a continuation of U.S. Provisional Patent Application No.
60/033,321 filed Dec. 12, 1996, the full disclosures of which are
hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to robotically-assisted surgical
manipulators and more particularly to systems and methods for
performing telerobotic surgical procedures on a patient while
providing the surgeon with the sensation of physical presence at
the surgical site.
[0003] In robotically-assisted or telerobotic surgery, the surgeon
typically operates a master controller to remotely control the
motion of surgical instruments at the surgical site from a location
that may be remote from the patient (e.g., across the operating
room, in a different room or a completely different building from
the patient). The master controller usually includes one or more
hand input devices, such as joysticks, exoskeletal gloves or the
like, which are coupled to the surgical instruments with servo
motors for articulating the instruments at the surgical site. The
servo motors are typically part of an electromechanical device or
surgical manipulator ("the slave") that supports and controls the
surgical instruments that have been introduced directly into an
open surgical site or through trocar sleeves into a body cavity,
such as the patient's abdomen. During the operation, the surgical
manipulator provides mechanical articulation and control of a
variety of surgical instruments, such as tissue graspers, needle
drivers, electrosurgical cautery probes, etc., that each perform
various functions for the surgeon, e.g., holding or driving a
needle, grasping a blood vessel, or dissecting, cauterizing or
coagulating tissue.
[0004] This new method of performing telerobotic surgery through
remote manipulation has, of course, created many new challenges.
One such challenge results from the fact that a portion of the
electromechanical surgical manipulator will be in direct contact
with the surgical instruments, and will also be positioned adjacent
the operation site. Accordingly, the surgical manipulator may
become contaminated during surgery and is typically disposed of or
sterilized between operations. Of course, from a cost perspective,
it would be preferable to sterilize the device. However, the servo
motors, sensors, encoders and electrical connections that are
necessary to robotically control the motors typically cannot be
sterilized using conventional methods, e.g., steam, heat and
pressure or chemicals, because they would be damaged or destroyed
in the sterilization process.
[0005] Yet another challenge with telerobotic surgery systems is
that a surgeon will typically employ a large number of different
surgical instruments during a procedure. Since the number of
instrument holders are limited due to space constraints and cost,
many of these surgical instruments will be attached and detached
from the same instrument holder a number of times during an
operation. In laparoscopic procedures, for example, the number of
entry ports into the patient's abdomen is generally limited during
the operation because of space constraints as well as a desire to
avoid unnecessary incisions in the patient. Thus, a number of
different surgical instruments will typically be introduced through
the same trocar sleeve during the operation. Likewise, in open
surgery, there is typically not enough room around the surgical
site to position more than one or two surgical manipulators, and so
the surgeon's assistant will be compelled to frequently remove
instruments from the holder and exchange them with other surgical
tools.
[0006] What is needed, therefore, are improved telerobotic systems
and methods for remotely controlling surgical instruments at a
surgical site on a patient. These systems and methods should be
configured for easy sterilization so that they can be reused after
the components have been contaminated during an operation. In
addition, these systems and methods should be designed to minimize
instrument exchange time during the surgical procedure.
SUMMARY OF THE INVENTION
[0007] The present invention provides systems and methods for
performing remote, robotically-assisted surgical procedures on a
patient while providing the surgeon with the sensation of physical
presence at the surgical site (i.e., telepresence). In particular,
a three-component surgical system is provided that includes a
non-sterile drive and control component, a sterilizable end
effector or surgical tool and an intermediate connector component
that includes mechanical elements for coupling the surgical tool
with the drive and control component, and for transferring motion
from the drive component to the surgical tool. The drive and
control component is shielded from the sterile surgical site, the
surgical tool is sterilizable and disposable and the intermediate
connector is sterilizable and reusable. In this manner, the
intermediate connector can be sterilized after a surgical procedure
without damaging the motors or electrical connections within the
drive and control component of the robotic system.
[0008] The drive and control component of the present invention
generally includes the drive actuators, e.g., motors, gears or
pulleys, etc., and positioning devices that are necessary to
articulate the surgical tool at the surgical site. In addition, the
drive and control component will usually include the encoders and
electrical connectors required to couple the component to a
servomechanism to form a master/slave telerobotic surgical system.
In a specific configuration of the invention, this component
comprises a manipulator assembly having a drive assembly and a
multiple degree of freedom manipulator arm. The arm and drive
assembly are covered by a sterile drape to effectively shield these
components from the sterile surgical field during the operation. In
this way, the portion of the system including motors, encoders and
fragile electronics does not have to be sterilized because it is
separated from the sterile field surrounding the surgical site.
[0009] The intermediate connector includes a sterile adaptor that
extends through an opening in the sterile drape to couple the
sterile surgical tool with the manipulator arm. The adaptor
includes a plurality of motion and electrical feed-throughs for
articulating the surgical tool, and for sending electrical signals
to and from the tool, e.g., force and torque feedback signals, etc.
In one configuration, the intermediate component includes a scope
adaptor for coupling a viewing scope, such as an endoscope coupled
to a camera mount and a camera, to the manipulator arm. In another
configuration, the intermediate connector includes a surgical
instrument assembly coupled to the sterile adaptor. The surgical
instrument assembly will usually include a surgical tool, which may
comprise a variety of articulated tools with end effectors, such as
jaws, scissors, graspers, needle holders, micro dissectors, staple
appliers, tackers, suction irrigation tools, clip appliers, or
non-articulated tools, such as cutting blades, cautery probes,
irrigators, catheters or suction orifices.
[0010] In a preferred configuration, the surgical instrument
assembly will further include a wrist unit for removably coupling
the surgical tool to the adaptor on the manipulator assembly. The
wrist unit comprises an elongate shaft with a distal wrist coupled
to the surgical tool for providing articulation of the tool about
the distal wrist. During a surgical procedure, the telerobotic
system will usually include a variety of surgical instrument
assemblies, each having a wrist unit with a different surgical tool
attached. The wrist units can be quickly and easily coupled and
decoupled from the manipulator assemblies to facilitate instrument
exchange during the procedure. In an exemplary embodiment, the
wrist unit is reposable, and it includes a mechanism for counting
the number of times the wrist unit is used to inhibit further use
of the unit.
[0011] The manipulator assembly provides a plurality of degrees of
freedom to the wrist unit and surgical tool including pitch and yaw
movement of the tool about the wrist, rotation about the wrist
shaft axis, axial movement and articulation of the end effector on
the surgical tool. In addition, the manipulator assembly preferably
provides pitch and yaw motion of the wrist unit and the surgical
tool about axes perpendicular to the wrist shaft. The motors of the
drive assembly are located proximally from the arm and the
intermediate component, which facilitates cleaning, decreases the
cost of manufacturing the assembly and decreases the inertia of the
surgical tool and wrist unit. In a preferred configuration, the
manipulator assembly will include a remote center positioning
device, such as a parallelogram linkage, for constraining motion of
the wrist unit and/or surgical tool about a desired fixed center of
rotation. This fixed center of rotation may be located on the wrist
unit shaft, at the distal wrist, or in endoscopic procedures,
coincident with the entry incision within the patient's body.
[0012] In an exemplary embodiment, the three-component surgical
manipulator of the present invention is part of a telerobotic
system in which the surgeon manipulates input control devices and
views the operation via a displayed image from a location remote
from the patient. The system includes a servomechanism coupled to
one or more manipulator assemblies to control the wrist units and
surgical tools in response to the surgeon's manipulation of the
input control devices. Position, force, and tactile feedback
sensors (not shown) may also be employed to transmit position,
force, and tactile sensations from the surgical tools back to the
surgeon's hands as he/she operates the telerobotic system. A
monitor is coupled to the viewing scope such that the displayed
image of the surgical site is provided adjacent the surgeon's
hands. The image is preferably oriented so that the surgeon feels
that he or she is actually looking directly at the operating site.
This configuration provides the surgeon with telepresence, or the
perception that the input control devices are integral with the
surgical tools.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic view of an operating room,
illustrating a telerobotic surgical system and method according to
the present invention.
[0014] FIG. 2 is an enlarged view of the operating room of FIG. 1
illustrating a pair of mounting joints coupled to an operating
table according to the present invention.
[0015] FIG. 3A is a perspective view of a robotic surgical
manipulator according to the present invention that is partially
covered by a sterile drape.
[0016] FIG. 3B is a perspective view of the robotic surgical
manipulator without the sterile drape to illustrate a multiple
degree of freedom arm coupling a driving assembly with a wrist unit
and a surgical tool.
[0017] FIG. 4 illustrates the robotic surgical manipulator of FIGS.
3A-3B incorporating a camera and endoscope for viewing the surgical
site.
[0018] FIG. 5 is a partial view of the robotic manipulator of FIGS.
3A-3B, illustrating mechanical and electrical couplings between the
arm and the wrist unit.
[0019] FIG. 6 is a partially cut-away sectional view of a forearm
and a carriage of the manipulator of FIGS. 3a and 3B.
[0020] FIG. 7 is a perspective view of the wrist unit according to
the present invention.
[0021] FIG. 8 is a side cross-sectional view of a portion of the
robotic manipulator, illustrating the arm and the drive
assembly.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0022] The present invention provides a multi-component system and
method for performing robotically-assisted surgical procedures on a
patient, particularly including open surgical procedures,
neurosurgical procedures, such as stereotaxy, and endoscopic
procedures, such as laparoscopy, arthroscopy, thoracoscopy and the
like. The system and method of the present invention is
particularly useful as part of a telerobotic surgical system that
allows the surgeon to manipulate the surgical instruments through a
servomechanism from a remote location from the patient. To that
end, the manipulator apparatus or slave of the present invention
will usually be driven by a kinematically-equivalent master to form
a telepresence system with force reflection. A description of a
suitable slave-master system can be found in co-pending patent
application Ser. No. 08/517,053, filed Aug. 21, 1995 (Attorney
Docket No. 287-004810), the complete disclosure of which is
incorporated herein by reference.
[0023] Referring to the drawings in detail, wherein like numerals
indicate like elements, a telerobotic surgical system 2 is
illustrated according to the present invention. As shown in FIG. 1,
telerobotic system 2 generally includes one or more surgical
manipulator assemblies 4 mounted to or near an operating table O,
and a control assembly 6 for allowing the surgeon S to view the
surgical site and to control the manipulator assemblies 4. The
system 2 will also include one or more viewing scope assemblies 19
and a plurality of surgical instrument assemblies 20 adapted for
being removably coupled to manipulator assemblies 4 (discussed in
detail below). Telerobotic system 2 usually includes at least two
manipulator assemblies 4 and preferably three manipulator
assemblies 4. Of course, the exact number of manipulator assemblies
4 will depend on the surgical procedure and the space constraints
within the operating room among other factors. As discussed in
detail below, one of the assemblies 4 will typically operate a
viewing scope assembly 19 (in endoscopic procedures) for viewing
the surgical site, while the other manipulator assemblies 4 operate
surgical instruments 20 for performing various procedures on the
patient P.
[0024] Control assembly 6 may be located at a surgeon's console C
which is usually located in the same room as operating table O so
that the surgeon may speak to his/her assistant(s) A and directly
monitor the operating procedure. However, it will be understood
that the surgeon S can be located in a different room or a
completely different building from the patient P. Control assembly
6 generally includes a support 8, a monitor 10 for displaying an
image of the surgical site to the surgeon S, and one or more
controller(s) 12 for controlling manipulator assemblies 4.
Controller(s) 12 may include a variety of input devices, such as
joysticks, gloves, trigger-guns, hand-operated controllers, voice
recognition devices or the like. Preferably, controller(s) 12 will
be provided with the same degrees of freedom as the associated
surgical instrument assemblies 20 to provide the surgeon with
telepresence, or the perception that the controller(s) 12 are
integral with the instruments 20 so that the surgeon has a strong
sense of directly controlling instruments 20. Position, force, and
tactile feedback sensors (not shown) may also be employed on
instrument assemblies 20 to transmit position, force, and tactile
sensations from the surgical instrument back to the surgeon's hands
as he/she operates the telerobotic system. One suitable system and
method for providing telepresence to the operator is described in
co-pending patent application Ser. No. 08/517,053, filed Aug. 21,
1995, (Attorney Docket No. 0287S-004810), which has previously been
incorporated herein by reference.
[0025] Monitor 10 will be suitably coupled to the viewing scope
assembly 19 such that an image of the surgical site is provided
adjacent the surgeon's hands on surgeon console 6. Preferably,
monitor 10 will display an inverted image on a display 18 that is
oriented so that the surgeon feels that he or she is actually
looking directly down onto the operating site. To that end, an
image of the surgical instruments 20 appears to be located
substantially where the operator's hands are located even though
the observation points (i.e., the endoscope or viewing camera) may
not be from the point of view of the image. In addition, the
real-time image is preferably transformed into a perspective image
such that the operator can manipulate the end effector and the hand
control as if viewing the workspace in substantially true presence.
By true presence, it is meant that the presentation of an image is
a true perspective image simulating the viewpoint of an operator
that is physically manipulating the surgical instruments 20. Thus,
a controller (not shown) transforms the coordinates of the surgical
instruments 20 to a perceived position so that the perspective
image is the image that one would see if the camera or endoscope
was located directly behind the surgical instruments 20. A suitable
coordinate transformation system for providing this virtual image
is described in patent application Ser. No. 08/239,086, filed May
5, 1994, (Attorney Docket No. 0287S-003300), the complete
disclosure of which is incorporated herein by reference.
[0026] As shown in FIG. 1, a servomechanism 16 is provided for
transferring the mechanical motion of controllers 12 to manipulator
assemblies 4. Servomechanism 16 may be separate from, or integral
with manipulator assemblies 4. Servomechanism 16 will usually
provide force and torque feedback from the surgical instruments 20
to the hand-operated controllers 12. In addition, servomechanism 16
will include a safety monitoring controller (not shown) that may
freeze or at least inhibit all robot motion in response to
recognized conditions (e.g., exertion of excessive force on the
patient, "running away" of the manipulator assemblies 4, etc.). The
servomechanism preferably has a servo bandwidth with a 3 dB cut off
frequency of at least 10 Hz so that the system can quickly and
accurately respond to the rapid hand motions used by the surgeon.
To operate effectively with this system, manipulator assemblies 4
have a relatively low inertia and the drive motors 170 (see FIG. 8)
have relatively low ratio gear or pulley couplings. Any suitable
conventional or specialized servomechanism may be used in the
practice of the present invention, with those incorporating force
and torque feedback being particularly preferred for telepresence
operation of the system.
[0027] Referring to FIG. 7, surgical instrument assemblies 20 each
include a wrist unit 22 and a surgical tool 24 removably attached
to wrist unit 22. As discussed in detail below, each wrist unit 22
generally includes an elongate shaft 56 having a proximal cap 58
and a distal wrist 60 pivotally coupled to surgical tool 24. Each
wrist unit 22 is substantially the same, and will have different or
the same surgical tools 24 attached thereto, depending on the
requirements of the surgical procedure. Alternatively, wrist units
22 may have specialized wrists 60 designed for individual surgical
tools 24 so that the wrist units 22 may be used with conventional
tools 24. As shown in FIG. 1, the instrument assemblies 20 are
usually assembled onto a table T or other suitable support adjacent
the operating table O. According to a method of the present
invention (described below), wrist units 22 and their associated
surgical tools 24 can be quickly exchanged during the surgical
procedure by coupling and decoupling wrist unit shafts 56 from
manipulator assemblies 4.
[0028] Referring to FIG. 2, each manipulator assembly 4 is
preferably mounted to operating table O by a mounting joint 30.
Mounting joints 30 provide a number of degrees of freedom
(preferably at least 5) to assemblies 4, and they include a brake
(not shown) so that assemblies 4 can be fixed at a suitable
position and orientation relative to the patient. Joints 30 are
mounted to a receptacle 32 for mounting joints 30 to operating
table O, and for connecting each manipulator assembly 4 to
servomechanism 16. In addition, receptacle 32 may connect joints 30
to other systems, such as an RF electrical power source, a
suction-irrigation system, etc. Receptacle 32 includes a mounting
arm 34 that is slidably disposed along an outer rail 36 of
operating table O. Of course, manipulator assemblies 4 may be
positioned over the operating table O with other mechanisms. For
example, the system may incorporate a support system (coupled to
the ceiling or a wall of the operating room) that moves and holds
one or more manipulator assemblies 4 over the patient.
[0029] Referring now to FIGS. 3-8, manipulator assembly 4 will be
described in further detail. Manipulator assembly 4 is a
three-component apparatus that includes a non-sterile drive and
control component, a sterilizable end effector or surgical tool
(i.e., surgical instrument assembly 20) and an intermediate
connector component. The intermediate connector includes mechanical
elements for coupling the surgical tool 24 with the drive and
control component, and for transferring motion from the drive
component to the surgical tool 24. As shown in FIG. 3B, the drive
and control component generally includes a drive assembly 40 and a
multiple degree of freedom robotic arm 42 coupled to a mounting
bracket 44, which is adapted for mounting onto mounting joints 30
(FIG. 2). Preferably, drive assembly 40 and robotic arm 42 are
pivotally coupled to bracket 44 about an X-axis, which extends
through a remote center of spherical rotation 45 (see FIG. 8,
discussed in further detail below). Manipulator assembly 4 further
includes a forearm assembly 46 fixed to a distal end 48 of arm 42,
and a wrist unit adaptor 52 coupled to forearm assembly 46 for
mounting wrist unit 22 and surgical tool 24 to manipulator assembly
4.
[0030] For endoscopic procedures, manipulator assembly 4
additionally includes a cannula adaptor 64 attached to a lower
portion of forearm 46 for mounting a cannula 66 to manipulator
assembly 4. Alternatively, cannula 66 may be an integral cannula
(not shown) that is built into forearm assembly 46 (i.e.,
non-removable). Cannula 66 may include a force sensing element (not
shown), such as a strain gauge or force-sensing resistor, mounted
to an annular bearing within cannula 66. The force sensing bearing
supports surgical tool 24 during surgery, allowing the tool to
rotate and move axially through the central bore of the bearing. In
addition, the bearing transmits lateral forces exerted by the
surgical tool 24 to the force sensing element, which is connected
to servomechanism 16 for transmitting these forces to controller(s)
12. In this manner, forces acting on surgical tools 24 can be
detected without disturbances from forces acting on cannula 66,
such as the tissue surrounding the surgical incision, or by gravity
and inertial forces acting on manipulator assembly 4. This
facilitates the use of manipulator assembly in a robotic system
because the surgeon will directly sense the forces acting against
the surgical tool 24.
[0031] As shown in FIG. 3A, manipulator assembly 4 further includes
a sterile drape 70 sized to cover substantially the entire
manipulator assembly 4. Drape 70 has a pair of holes 72, 74 sized
and arranged so that wrist unit adaptor 52 and cannula adaptor 64
may extend through holes 72, 74 to mount wrist unit 22 and cannula
66 to manipulator assembly 4. Sterile drape 70 comprises a material
configured to effectively shield manipulator assembly 4 from the
surgical site so that most of the components of assembly 4 (i.e.,
arm 42, drive assembly 40 and forearm assembly 46) do not have to
be sterilized prior to, or following the surgical procedure.
[0032] As shown in FIG. 3A, wrist unit adaptor 52 and cannula
adaptor 64 extend through holes 72, 74 of drape 70 so that forearm
assembly 46 and the remainder of manipulator assembly 4 remain
shielded from the patient during the procedure. Wrist unit adaptor
52 and cannula adaptor 64 are preferably manufactured as reusable
components that will be sterilized because these components extend
into the sterile field of the surgical site. Wrist unit and cannula
adapters 52, 64 may be sterilized by normal methods, i.e., steam,
heat and pressure, chemicals and the like. Referring again to FIG.
3B, wrist unit adaptor 52 includes an opening 80 for receiving
shaft 56 of wrist unit 22. As discussed in detail below, shaft 56
can be laterally urged through opening 80 and snap-fit into adaptor
52 such that the non-exposed portion of wrist unit adaptor 52
remains sterile (i.e., remains on the sterile side of drape 70
opposite the sterile field). Wrist unit adaptor 52 may also include
a latch (not shown) for securing wrist unit 22 therein. Similarly,
cannula adaptor 64 includes an opening 82 for snap fitting cannula
66 thereto such that the non-exposed portion of adaptor 64 remains
sterile during the surgical procedure.
[0033] As shown in FIG. 4, wrist unit adaptor 52 may also be
configured to receive a viewing scope 100 for viewing the surgical
site. For endoscopic procedures, viewing scope 100 can be a
conventional endoscope, which typically includes a rigid, elongated
tube 102 containing a lens system (not shown) and a camera mount
104 at the proximal end of the tube 102. A small video camera 106
is preferably attached to the camera mount 104 and connected to
video monitor 10 to provide a video image of the procedure.
Preferably, the scope 100 has a distal end (not shown) configured
to allow lateral or angled viewing relative to tube 102. The
viewing scope may also have a guidable tip that can be deflected or
rotated by manipulating an actuator on a proximal end of tube 102.
This type of scope is commercially available from Baxter Healthcare
Corp. of Deerfield, Ill., or Origin Medsystems, Inc. of Menlo Park,
Calif.
[0034] As shown in FIG. 4, viewing scope 100 further includes a
scope adaptor 110 for coupling viewing scope 100 to wrist unit
adaptor 52. Scope adaptor 110 is sterilizable, ETO and
autoclavable, and it includes a plurality of motion feed-throughs
(not shown) for transferring motion from drive assembly 40 to scope
100. In the preferred configuration, the motion includes pitch and
yaw motion, rotation about the Z-axis, and movement along the
Z-axis.
[0035] Referring now to FIGS. 5 and 6, forearm assembly 46 will be
described in further detail. As shown in FIG. 5, forearm assembly
46 includes a housing 120 fixed to arm 42 and a movable carriage
122 slidably coupled to housing 120. Carriage 122 slidably mounts
wrist unit adaptor 52 to housing 120 for moving wrist unit adaptor
52 and wrist unit 20 in the Z-direction. In addition, carriage 122
defines a number of openings 123 for transferring motion and
electrical signals from forearm assembly 46 to wrist unit adaptor
52. As shown in FIG. 6, a plurality of rotatable shafts 124 are
mounted within housing 120 for transferring motion from arm 42
through openings 123 to wrist unit adaptor 52 and wrist unit 22.
Rotating shafts 124 preferably provide at least four degrees of
freedom to wrist unit 22, including yaw and pitch motion of
surgical tool 62 about wrist 60 of wrist unit 22, rotation of wrist
unit 22 about the Z-axis and actuation of tool 62. Of course, the
system may be configured to provide more or less degrees of
freedom, if desired. Actuation of tool 62 may include a variety of
motions, such as opening and closing jaws, graspers or scissors,
applying clips or staples and the like. Motion of wrist unit 22 and
tool 62 in the Z direction is provided by a pair of carriage cable
drives 126 extending between rotatable pulleys 128, 129 on either
end of forearm housing 120. Cable drives 126 function to move
carriage 122 and wrist unit 22 in the Z direction relative to
forearm housing 120.
[0036] As shown in FIG. 6, distal end 48 of arm 42 includes a
coupling assembly 130 having a plurality of motion feed-throughs
132 for transferring motion from arm 42 to forearm assembly 46. In
addition, coupling assembly 130 includes a number of electrical
connectors (not shown) for transferring electrical signals from arm
42 to wrist unit 22. Similarly, wrist unit adaptor 52 includes a
plurality of motion feed-throughs (not shown) and electrical
connections (not shown) for transferring motion, and for sending
and receiving electrical signals to and from wrist unit 22 (e.g.,
for sending and receiving force and torque feedback signals from
the surgical site to controllers 12). The components on either side
of coupling assembly 130 and wrist unit adaptor 52 have a finite
range of motion. Usually, this range of motion will be at least 1
revolution and preferably greater than 1 revolution. These ranges
of motion are aligned with each other when the forearm assembly 46
is mechanically coupled to the coupling assembly 130 and when wrist
unit adaptor 52 is mechanically coupled to the forearm 46.
[0037] Referring to FIG. 7, wrist unit 22 will now be described in
further detail. As shown, wrist unit 22 includes a hollow shaft 56
having a cap 58 attached to its proximal end and a wrist 60
attached to its distal end. Wrist 60 includes a coupling (not
shown) for removably coupling a variety of surgical tools 62 to
shaft 56. Shaft 56 is rotatably coupled to cap 58 for providing
rotation of shaft 56 and tool 62 about the longitudinal axis of
shaft 56 (i.e., the Z axis). Cap 58 houses a mechanism (not shown)
for transferring motion from wrist unit adaptor 52 to drive cables
(not shown) within shaft 56. The drive cables are suitably coupled
to drive pulleys within shaft 56 to pivot tool 62 about wrist 60,
and to actuate end effectors 140 on tool 62. Wrist 60 may also be
operated by other mechanisms, such as differential gears,
push-rods, or the like.
[0038] Tool 62 is removably coupled to wrist 60 of wrist unit 22.
Tool 62 will preferably include an end effector 65 having a tactile
sensor array (not shown) for providing tactile feedback to the
surgeon. Tool 62 may include a variety of articulated tools, such
as jaws, scissors, graspers, needle holders, micro dissectors,
staple appliers, tackers, suction irrigation tools, clip appliers,
that have end effectors driven by wire links, eccentric cams,
push-rods or other mechanisms. In addition, tool 62 may comprise a
non-articulated instrument, such as cutting blades, probes,
irrigators, catheters or suction orifices. Alternatively, tool 62
may comprise an electrosurgical probe for ablating, resecting,
cutting or coagulating tissue. In the latter embodiment, wrist unit
22 will include a conductive element, such as a proximal banana
plug coupled to a lead wire or rod extending through shaft 56 to
tool 62.
[0039] Referring to FIGS. 4 and 8, a specific configuration of the
drive and control component of the present invention (i.e., the
robotic arm 42 and drive assembly 40) will be described in further
detail. As discussed above, arm 42 and drive assembly 40 are
rotatably coupled about a pair of pins 150 extending from mounting
bracket 44. Arm 42 preferably comprises an elongate, substantially
rigid body 152 with a distal end 48 coupled to forearm assembly 48
and a proximal end 154 pivotally coupled to drive assembly 40 and
bracket 44 for rotation about pitch and yaw or the X and Y axes
(note that the Y axis is perpendicular to the page and extends
through point 45, see FIG. 8). Of course, arm 40 may have other
configurations, such as an elbow arm (similar to the human arm),
prismatic arm (straight extendable) or the like. A stationary yaw
motor 156 is mounted to mounting bracket 44 for rotating arm 42 and
drive assembly 40 about the X-axis. Drive assembly 40 also includes
a pitch motor 158 coupled to arm 42 for rotating arm about the Y
axis. A pair of substantially rigid linkage elements 160, 162
extend from bracket 44 to robotic arm 42 to pivotally couple arm 42
to bracket 44 about Y-axis. One of the linkage elements 160 is
pivotally coupled to arm 42, and the other linkage element 162 is
pivotally coupled to a third linkage element 164 extending parallel
to arm 42. Preferably, robotic arm 42 is a channel shaped rigid
element that at least partially houses the third linkage element
164. The linkage elements 160, 162 and 164 and arm 42 form a
parallelogram linkage in which the members are connected together
in a parallelogram for relative movement only in the plane formed
by the members.
[0040] The Z-axis of wrist unit 22 held at the distal end 48 of arm
42 intersects the x axis of the parallelogram linkage described
above. Wrist unit 22 has a remote center of spherical rotation
about the position indicated by the numeral 45 in FIG. 8. Thus, the
distal end of wrist unit 22 can be rotated about its own axis or
the X and Y axes while the remote center of rotation 45 remains at
the same location. A more complete description of a remote center
positioning device can be found in co-pending application Ser. No.
08/504,301, filed Jul. 20, 1995 (Attorney Work Docket 287-002940),
the complete disclosure of which is incorporated herein by
reference. It should be noted that arm 42 and drive assembly 40 may
be used with a broad range of positioning devices other than that
described above and shown in FIG. 8, such as a stereotaxic
positioner, a fixed gimbal or the like.
[0041] Referring again to FIG. 8, drive assembly 40 further
includes a plurality of drive motors 170 coupled to arm 42 for
rotation therewith. Pitch and yaw motors 156, 158 control the
motion of arm 42 (and drive motors 170) about the X and Y axes and
drive motors 170 control the motion of wrist unit 22 and surgical
tool 24. Preferably, at least five drive motors 170 are coupled to
arm 42 for providing at least five degrees of freedom to wrist unit
24. Drive motors 170 will preferably include encoders (not shown)
for responding to servomechanism 16 and force sensors (not shown)
for transmitting force and torque feedback to the surgeon S. As
discussed above, the five degrees of freedom preferably include
movement of carriage 122 and wrist unit 22 in the Z-direction,
rotation of wrist unit 22 about the Z-axis, pitch and yaw rotation
of surgical tool 62 around wrist 60 and actuation of tool 62.
[0042] As shown, cables 172 extend from each motor 170 around a
motor drive pulley 174, an idler pulley 176 within arm 42 and along
a relatively large pot capstan 178 to minimize the effect of
friction torque on cables 172. The cables 172 each extend around
another idler pulley 180 at distal end 48 of arm 42, around a
coupling drive pulley 182 and back to the motor 170. The cables 172
will preferably be tensioned at the motor drive pulley 174 and
anchored there as well as at the coupling drive pulley 182. As
shown in FIG. 8, coupling drive pulley 182 is connected to a
plurality of smaller pulleys 184 within coupling assembly 130 via a
plurality of cables 186 for transferring motion from the motors 170
to wrist unit adaptor 52.
[0043] A method for performing a surgical procedure on a patient
according to the present invention will now be described with
reference to FIGS. 1-9. As shown in FIG. 2, mounting joints 30 are
attached to receptacle 32, which is attached to the operating table
O by sliding mounting arm 34 along rail 36. Each manipulator
assembly 4 is then attached to its respective mounting joint 30 and
articulated into the proper position and orientation relative to
the patient P. Receptacles 32 are then coupled to servomechanism 16
and other systems that may be required during the surgical
procedure, such as an RF power supply, a suction/irrigation system,
etc. Sterile drapes 70 are placed over the manipulator assemblies 4
before, during or after the patient has been anesthetized (FIG.
3A). To prepare for the surgical procedure, manipulator assemblies
4 may or may not be chemically cleaned prior to covering them with
drapes 70. Wrist unit adapters 52, cannula adapters 64 and scope
adapters 110 are snapped onto forearm assemblies 46 of manipulator
assemblies 4 (see FIGS. 3B and 5). The number and relative
positions of scope adapters 110 and wrist unit adapters 52 will, of
course, depend on the individual surgical procedure (e.g., cannula
adapters 64 may not be required for open surgical procedures).
[0044] During the surgical procedure, surgical instrument
assemblies 20 are coupled to their respective manipulator
assemblies 4 by laterally urging each respective wrist unit shaft
56 through opening 80 of wrist unit adaptor 52. Each wrist unit 22
will have suitable identification means (not shown) to quickly and
easily indicate what type of tool 24 is connected to the wrist unit
22. When the surgeon wishes to change surgical tools 24, he or she
manipulates controller(s) 12 so that carriage 122 moves to a top or
proximal position of travel along forearm assembly 46 (see FIG.
3B). In this position, surgical tool 24 is within cannula 66 or
during open procedures, removed from the surgical site. The
assistant(s) A then pulls upward on wrist cap 58 to release the
latch (not shown), thereby allowing wrist unit 22 to slide further
upwards and out of cannula 66. The assistant(s) A may then pull
wrist unit 22 laterally to decouple it from wrist unit adaptor 52.
When wrist unit 22 is no longer coupled to adaptor 52, the control
mechanism understands that the system in is "tool change mode", and
drives carriage 122 to the proximal position if it hasn't already
been moved there by the surgeon.
[0045] To couple another surgical instrument assembly 20 to
manipulator assembly 4, the assistant(s) A grabs another assembly
20 from table T, laterally urges wrist unit shaft 56 into opening
80 of wrist unit adaptor 52, and then moves wrist unit 22 downward
so that surgical tool 62 resides within cannula 66 (see FIGS. 1 and
3B). This downward movement of wrist unit 22 automatically mates
the electrical couplings and motion feed-throughs (not shown)
within wrist cap 58 and wrist unit adaptor 52. The system may
include a control mechanism configured to lock carriage 122 travel
at the top or proximal position, e.g., by actuating a brake (not
shown), until the couplings are mated and wrist unit 22 is no
longer being moved downward. At this point, the surgeon S may
continue the surgical procedure.
[0046] The system and method of the present invention preferably
includes a mechanism for counting the number of times wrist unit 22
is decoupled and coupled from wrist unit adaptor 52. In this
manner, the manufacturer may limit the number of times wrist unit
22 can be used. In a specific configuration, an integrated circuit
chip (not shown) is housed within wrist cap 58. The circuit chip
counts the number of times wrist unit 22 is coupled to wrist unit
adaptor 52, e.g., 20 times, and a warning shows up on the surgeon's
console C. The control system then downgrades the performance of
the system by reducing the load it can deliver or increasing
apparent backlash.
* * * * *