Source: https://patents.google.com/patent/US9757203B2/en
Timestamp: 2019-07-23 09:55:39
Document Index: 707398151

Matched Legal Cases: ['Application No. 61', 'art 22', 'art 24', 'art 22', 'art 22', 'art 24', 'art 22', 'art 22', 'art 54', 'art 56', 'art 24', 'art 56', 'art 56', 'art 54', 'art 56', 'art 54', 'art 56', 'art 56', 'art 22', 'art 24', 'art 24', 'art 24', 'Application No. 13796945', 'Application No. 201380027983']

US9757203B2 - Manipulator arm-to-patient collision avoidance using a null-space - Google Patents
US9757203B2
US9757203B2 US15/351,254 US201615351254A US9757203B2 US 9757203 B2 US9757203 B2 US 9757203B2 US 201615351254 A US201615351254 A US 201615351254A US 9757203 B2 US9757203 B2 US 9757203B2
US15/351,254
US20170056117A1 (en
2016-11-14 Application filed by Intuitive Surgical Operations Inc filed Critical Intuitive Surgical Operations Inc
2017-03-02 Publication of US20170056117A1 publication Critical patent/US20170056117A1/en
2017-09-12 Publication of US9757203B2 publication Critical patent/US9757203B2/en
This application is a divisional of U.S. application Ser. No. 13/906,713, filed May 31, 2013, which is a Non-Provisional of and claims the benefit of priority from U.S. Provisional Patent Application No. 61/654,755, filed on Jun. 1, 2012, and entitled “Manipulator Arm-to-Patient Collision Avoidance Using a Null-Space,” the full disclosure of each of which is incorporated herein by reference in its entirety.
FIG. 7 shows an example system having multiple manipulator arms and an obstacle surface modeled an as to extend through the remote center of the each of the manipulator arms.
FIGS. 13-14 are simplified block diagrams representing methods in accordance with many embodiments,
Despite the many advantages of a robotic surgical system having multiple highly configurable manipulators, since the manipulators include a relatively large number of joints and links between the base and instrument, movement of the manipulator arms can be particularly complex. As the range of configurations and range of motion of the manipulator arm increases no does the likelihood of arm-to-patient collisions between a portion of the manipulator arm proximal of the distal end effector and an outer surface of the patient. For example, the considerable range of motion of a manipulator arm having a distal tool that pivots about a remote center adjacent a minimally invasive aperture, as described herein, can allow a feature of the manipulator arm or a distal link of the manipulator arm itself to contact and/or collide with an outer surface of the patient. Since it can be difficult for a user to predict when such contact might occur due to the complexity of the movement of the manipulator arm, the present invention avoids such arm-to-patient collisions by calculating an avoidance movement of the manipulator arm and driving the joints to effect the avoidance movement while maintaining the desired state of a distal portion or tool of the manipulator arm.
Referring now to the drawings, in which like reference numerals represent like parts throughout the several views, FIG. 1A is an overhead view illustration of a Minimally Invasive Robotic Surgical (MIRS) system 10, in accordance with many embodiments, for use in performing a minimally invasive diagnostic or surgical procedure on a Patient 12 who is lying down on an Operating table 14. The system can include a Surgeon's Console 16 for use by a surgeon 18 during the procedure. One or more Assistants 20 may also participate in the procedure. The MIRS system 10 can further include a Patient Side Cart 22 (surgical robot and an Electronics Cart 24. The Patient Side Cart 22 can manipulate at least one removably coupled tool assembly 26 (hereinafter simply referred to as a “tool”) through a minimally invasive incision in the body of the Patient 12 while the surgeon 18 views the surgical site through the Console 16. An image of the surgical site can be obtained by an endoscope 28, such as a stereoscopic endoscope, which can be manipulated by the Patient Side Cart 22 so as to orient the endoscope 28. The Electronics Cart 24 can he used to process the images of the surgical site for subsequent display to the surgeon 18 through the Surgeon's Console 16. The number of surgical tools 26 used at one time will generally depend on the diagnostic or surgical procedure and the space constraints within the operating room among other factors. If it is necessary to change one or more of the tools 26 being used during a procedure, an Assistant 20 may remove the tool 26 from the Patient Side Cart 22, and replace it with another tool 26 from a tray 30 in the operating room,
FIG. 1B diagrammatically illustrates a robotic surgery system 50 (such as MIRS system 10 of FIG. 1A). As discussed above, a Surgeon's Console 52 (such as Surgeon's Console 16 in FIG. 1A) can be used by a surgeon to control a Patient Side Cart (Surgical Robot) 54 (such as Patent Side Cart 22 in FIG. 1A) during a minimally invasive procedure. The Patient Side Cart 54 can use an imaging device, such as a stereoscopic endoscope, to capture images of the procedure site and output the captured images to an Electronics Cart 56 (such as the Electronics Cart 24 in FIG. 1A). As discussed above, the Electronics Cart 56 can process the captured images in a variety of ways prior to any subsequent display. For example, the Electronics Cart 56 can overlay the captured images with a virtual control interface prior to displaying the combined images to the surgeon via the Surgeon's Console 52. The Patient Side Cart 54 can output the captured images for processing outside the Electronics Cart 56. For example, the Patient Side Cart 54 can output the captured images to a processor 58, which can he used to process the captured images. The images can also be processed by a combination the Electronics Cart 56 and the processor 58, which can be coupled together so as to process the captured images jointly, sequentially, and/or combinations thereof. One or more separate displays 60 can also be coupled with the processor 58 and/or the Electronics Cart 56 for local and/or remote display of images, such as images of the procedure site, or other related images.
FIG. 2 is a perspective view of the Surgeon's Console 16. The Surgeon's Console 16 includes a left eye display 32 and a right eye display 34 for presenting the Surgeon 18 with a coordinated stereo view of the surgical site that enables depth perception. The Console 16 further includes one or more input control devices 36, which in turn cause the Patient Side Cart 22 own in FIG. 1A) to manipulate one or more tools. The input control devices 36 can provide the same degrees of freedom as their associated tools 26 (shown in FIG. 1A) so as to provide the surgeon with telepresence, or the perception that the input control devices 36 are integral with the tools 26 so that the surgeon has a strong sense of directly controlling the tools 26. To this end, position, force, and tactile feedback sensors (not shown) may be employed to transmit position, force, and tactile sensations from the tools 26 back to the surgeon's hands through the input control devices 36.
FIG. 3 is a perspective view of the Electronics Cart 24. The Electronics Cart 24 can be coupled with the endoscope 28 and can include a processor to process captured images for subsequent display, such as to a surgeon on the Surgeon's Console, or on another suitable display located locally and/or remotely. For example, where a stereoscopic endoscope is used, the Electronics Cart 24 can process the captured images so as to present the surgeon with coordinated stereo images of the surgical site. Such coordination can include alignment between the opposing images and can include adjusting the stereo working distance of the stereoscopic endoscope. As another example, image processing can include the use of previously determined camera calibration parameters so as to compensate for imaging errors of the image capture device, such as optical aberrations,
In certain embodiments, such as shown for example in FIG. 5A, an example manipulator arm includes a proximal revolute joint J1 that rotates about a first joint axis so as to revolve the manipulator arm distal of the joint about the joint axis. In some embodiments, revolute joint J1 is mounted directly to the base, while in other embodiments, joint J1 may be mounted to one or more movable linkages or joints. The joints of the manipulator, in combination, have redundant degrees of freedom such that the joints of the manipulator arm can be driven into a range of differing configurations for a given end effector position. For example, the manipulator arm of FIGS. 5A-5D may be maneuvered into differing configurations while the distal member 511 (such as a cannula through which the tool 512 or instrument shaft extends) supported within the instrument holder 510 maintains a particular state and may include a given position or velocity of the end effector. Distal member 511 is typically a cannula through which the tool shaft 512 extends, and the instrument holder 510 is typically a carriage (shown as a brick-like structure that translates on a spar) to which the instrument attaches before extending through the cannula 511 into the body of the patient through the minimally invasive aperture:
In certain embodiments, the system defines an “avoidance geometry” 700 that includes one or more reference points, segments, or volumes that correspond to the components or features of the manipulator arm. For example, the distal end of linkage 510, often called the “spar” linkage, that joins with instrument cannula 511 generally protrudes towards the patient when the tool is positioned within the surgical workspace. This feature, sometimes known as the “spar knuckle” is of concern as it could potentially contact or collide with the outer patient surface as the instrument cannula 511 rotates around its remote center RC. To avoid such collisions, therefore, the system defines the “avoidance geometry “and determines its proximity to the patient surface, typically using joint sensors from which the position or velocity of the “avoidance geometry” can be determined. Embodiments may also use proximity sensors mounted on the driven linkages or slaves that can locally sense a proximity of a patient surface. In an example embodiment, the avoidance geometry 700 includes a reference corresponding to the “spar knuckle” 702, but may include additional references corresponding to other features of the manipulator arm, such as portion 704 near the instrument wrist or a distal portion of linkage 504, that could potentially collide with a patient surface during a surgical procedure.
In accordance with many embodiments, avoidance movement may be calculated according to a number of differing methods, which can include determining “nearest points” between the manipulator arm and the patient surface The nearest points can be determined either using calculations based on knowing the manipulator positions or states via joint sensors or can be approximated using other suitable means, such as an external sensor, video, sonar, capacitive, a touch sensor, or the like.
In an example embodiment, the system includes a controller in which a commanded position and velocity of a feature in the work-space, denoted here as its Cartesian space, are inputs. The feature may be any feature on the manipulator or off the manipulator which can be used as a control frame to he articulated using control inputs. An example of a feature on the manipulator, used in various examples described herein, would be the tool-tip. Another example of a feature on the manipulator would be a physical feature which is not on the tool-tip, but is a part of the manipulator, such as a pin or a painted pattern. An example of a feature off the manipulator would be a reference point in empty space which is exactly a certain distance and angle away from the tool-tip. Another example of a feature off the manipulator would be a target tissue whose position relative to the manipulator can be established. In all these cases, the end effector is associated with an imaginary control frame which is to be articulated using control inputs. However, in the following, the “end effector” and the “tool tip” are used synonymously. Although generally, there is no closed form relationship which maps a desired Cartesian space end effector position to an equivalent joint-space position, there is generally a closed form relationship between the Cartesian space end effector and joint-space velocities. The kinematic Jacobian is the matrix of partial derivatives of Cartesian space position elements of the end effector with respect to joint space position elements. In this way, the kinematic Jacobian captures the kinematic relationship between the end effector and the joints. In other words, the kinematic Jacobian captures the effect of joint motion on the end effector. The kinematic Jacobian (J) can be used to map joint-space velocities (dq/dt) to Cartesian space end effector velocities (dx/dt) using the relationship below:
dx/dt=dx des /dt+kΔx (1)
dq/dt=J # dx/dt (2)
q i =q i−1 +dq/dt Δt (3)
The pseudo-inverse of the Jacobian (J) directly maps the desired tool tip motion (and, in some cases, a remote center of pivotal tool motion) into the joint velocity space. If the manipulator being used has more useful joint axes than tool tip degrees of freedom (up to six), (and when a remote center of tool motion is in use, the manipulator should have an additional 3 joint axes for the 3 degrees of freedom associated with location of the remote center), then the manipulator is said to be redundant. A redundant manipulator's Jacobian includes a “null-space” having a dimension of at least one. In this context, the “null-space” of the Jacobian (N(J)) is the space of joint velocities which instantaneously achieves no tool tip motion (and when a remote center is used, no movement of the pivotal point location); and “null-motion” is the combination, trajectory, or path of joint positions which also produces no instantaneous movement of the tool tip and/or location of the remote center. Incorporating or injecting the calculated null-space velocities into the control system of the manipulator to achieve the desired reconfiguration of the manipulator including any reconfigurations described herein) changes above equation (2) to:
dq/dt=dq perp /dt dq null /dt (4)
dq prep /dt=dx/dt (5)
The joint velocity according to Equation (4) has two components: the first being the null-perpendicular-space component, the “purest” joint velocity (shortest vector length) which produces the desired tool tip motion (and when the remote center is used, the desired remote center motion); and the second being the null-space component. Equations (2) and (5) show that without a null-space component, the same equation is achieved. Equation (6) starts with a traditional form for the null-space component on the left, and on the far right side, shows the form used in an example system, wherein (Vn) is the set of orthonormal basis vectors for the null-space, and (α) are the coefficients for blending those basis vectors. In some embodiments, a is determined by control parameters, variables or setting, such as by use of knobs or other control means, to shape or control the motion within the null-space as desired,
a manipulator arm comprising a proximal portion coupled to the base, a movable distal portion, and a plurality of joints between the base and the distal portion, the plurality of joints together having sufficient degrees of freedom to allow a range of different joint states of the plurality of joints for a given pose of the distal portion of the manipulator arm;
receiving a manipulation command from the input device to move the distal portion of the manipulator arm with a first movement at a surgical work site of a patient;
calculating a displacing movement of the plurality of joints of the manipulator arm in response to the manipulation command so as to implement the first movement, wherein calculating the displacing movement comprises calculating joint movement within a null-perpendicular space of a Jacobian, the null-perpendicular space being orthogonal to a null-space of the Jacobian;
calculating an avoidance movement of the plurality of joints of the manipulator arm within the null-space of the Jacobian so as to implement a clearance between the manipulator arm and an outer surface of the patient within a range of motion of the manipulator arm; and
driving the plurality of joints of the manipulator arm according to the displacing movement and the avoidance movement.
2. The system of claim 1, wherein the controller is further configured to calculate a distance between an avoidance geometry of the manipulator arm and an obstacle surface, the obstacle surface corresponding to the patient outer surface, and the avoidance geometry corresponding to a portion of the manipulator for which clearance from the patient outer surface is desired.
3. The system of claim 2, wherein the controller is further configured to drive the plurality of joints according to the calculated avoidance movement in response to a determination by the controller that the distance between the avoidance geometry and obstacle surface is less than desired.
the distal portion comprises a surgical instrument having an elongate shaft extending distally to a surgical end effector;
the displacing movement is calculated to effect a desired end effector state; and
the avoidance movement of the plurality of joints is calculated so as to maintain the desired end effector state.
the manipulator arm is configured to support a tool having a shaft with an intermediate portion extending along an insertion axis of the tool to a distal end effector; and
at least some joints of the plurality of joints mechanically constrain movement of the distal portion relative to the base so that the distal portion of the manipulator arm pivots about a remote center disposed adjacent the insertion axis to facilitate movement of the end effector within the surgical work site, wherein the work site is accessed through an insertion opening.
6. The system of claim 5, wherein the controller is further configured to determine the obstacle surface by approximating or modeling a surface that intersects with the remote center.
the system comprises one or more additional manipulator arms, each having a remote center; and
the processor is configured to determine the obstacle surface by approximating or modeling the surface so as to intersect with each of the remote center positions.
8. The system of claim 1, wherein the controller is configured to calculate end effector displacing movement so as to not drive one or more joints and to calculate the avoidance movement so as to include driving of the one or more joints.
9. The system of claim 8, wherein the one or more joints includes a first joint that pivots the insertion axis about an axis of the first joint, the axis extending through the remote center.
10. The system of claim 9, wherein an intermediate link is disposed proximal of and adjacent to the distal portion with the first joint therebetween, the first joint comprising a revolute joint mechanically constraining movement of the distal portion relative to the intermediate link to rotation about a first joint axis, the first joint axis extending from a second joint distally toward the intermediate link so as to intersect the insertion axis through the remote center.
a manipulator arm comprising a proximal portion coupled to the base, a movable distal portion, and a plurality of joints that kinematically couple a plurality of links between the base and the distal portion, the plurality of links together having sufficient degrees of freedom to allow a range of different link states of the plurality of links for a given pose of the distal portion of the manipulator arm;
calculating a displacing movement of the plurality of joints of the manipulator arm in response to the manipulation command so as to implement the first movement, wherein calculating the displacing movement comprises calculating link movement within a null-perpendicular space of a Jacobian, the null-perpendicular space being orthogonal to a null-space of the Jacobian;
calculating an avoidance movement of the plurality of links of the manipulator arm within the null-space of the Jacobian so as to implement a clearance between the manipulator arm and an outer surface of the patient within a range of motion of the manipulator arm; and
driving the plurality of joints that kinematically couple the plurality of links of the manipulator arm according to the displacing movement and the avoidance movement.
12. The system of claim 11, wherein the controller is further configured to calculate a distance between an avoidance geometry of the manipulator arm and an obstacle surface, the obstacle surface corresponding to the patient outer surface, and the avoidance geometry corresponding to a portion of the manipulator for which clearance from the patient outer surface is desired.
13. The system of claim 12, wherein the controller is further configured to drive the plurality of joints according to the calculated avoidance movement in response to a determination by the controller that the distance between the avoidance geometry and obstacle surface is less than desired.
16. The system of claim 15, wherein the controller is further configured to determine the obstacle surface by approximating or modeling a surface that intersects with the remote center.
18. The system of claim 11, wherein the controller is configured to calculate end effector displacing movement so as to not drive one or more joints and to calculate the avoidance movement so as to include driving of the one or more joints.
19. The system of claim 18, wherein the one or more joints includes a first joint that pivots the insertion axis about an axis of the first joint, the axis extending through the remote center.
20. The system of claim 19, wherein an intermediate link is disposed proximal of and adjacent to the distal portion with the first joint therebetween, the first joint comprising a revolute joint mechanically constraining movement of the distal portion relative to the intermediate link to rotation about a first joint axis, the first joint axis extending from a second joint distally toward the intermediate link so as to intersect the insertion axis through the remote center.
US15/351,254 1998-12-08 2016-11-14 Manipulator arm-to-patient collision avoidance using a null-space Active US9757203B2 (en)
US13/906,713 Division US9492235B2 (en) 1998-12-08 2013-05-31 Manipulator arm-to-patient collision avoidance using a null-space
US15/640,045 Continuation US10194997B2 (en) 1999-09-17 2017-06-30 Manipulator arm-to-patient collision avoidance using a null-space
US20170056117A1 US20170056117A1 (en) 2017-03-02
US9757203B2 true US9757203B2 (en) 2017-09-12
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