U.S. patent application number 14/330339 was filed with the patent office on 2014-10-30 for methods of controlling a robotic surgical tool with a display monitor.
This patent application is currently assigned to Intuitive Surgical Operations, Inc.. The applicant listed for this patent is Intuitive Surgical Operations, Inc.. Invention is credited to Brian D. Hoffman, William C. Nowlin.
Application Number | 20140323803 14/330339 |
Document ID | / |
Family ID | 41118300 |
Filed Date | 2014-10-30 |
United States Patent
Application |
20140323803 |
Kind Code |
A1 |
Hoffman; Brian D. ; et
al. |
October 30, 2014 |
METHODS OF CONTROLLING A ROBOTIC SURGICAL TOOL WITH A DISPLAY
MONITOR
Abstract
In one embodiment of the invention, a method for controlling a
robotic surgical tool is disclosed. The method for controlling a
robotic surgical tool includes moving a monitor displaying an image
of a robotic surgical tool; sensing motion of the monitor; and
translating the sensed motion of the monitor into motion of the
robotic surgical tool.
Inventors: |
Hoffman; Brian D.;
(Sunnyvale, CA) ; Nowlin; William C.; (Los Altos,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intuitive Surgical Operations, Inc. |
Sunnyvale |
CA |
US |
|
|
Assignee: |
Intuitive Surgical Operations,
Inc.
Sunnyvale
CA
|
Family ID: |
41118300 |
Appl. No.: |
14/330339 |
Filed: |
July 14, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12058661 |
Mar 28, 2008 |
8808164 |
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14330339 |
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Current U.S.
Class: |
600/109 ;
606/130 |
Current CPC
Class: |
A61B 34/37 20160201;
A61B 2017/00216 20130101; A61B 2017/00199 20130101; A61B 1/00188
20130101; A61B 2017/00477 20130101; A61B 1/00149 20130101; A61B
34/32 20160201; A61B 1/00039 20130101; A61B 1/045 20130101; A61B
34/30 20160201; A61B 34/25 20160201; A61B 2090/372 20160201; A61B
90/361 20160201; A61B 34/74 20160201 |
Class at
Publication: |
600/109 ;
606/130 |
International
Class: |
A61B 19/00 20060101
A61B019/00; A61B 1/045 20060101 A61B001/045 |
Claims
1. A method for controlling a robotic surgical tool, the method
comprising: supporting a monitor with a supporting device;
displaying an image of a robotic surgical tool on the monitor;
moving the monitor displaying the image of the robotic surgical
tool; sensing motion of the monitor; and translating the sensed
motion of the monitor into motion of the robotic surgical tool.
2. The method of claim 1, wherein the motion of the monitor is
sensed by an inertia sensor coupled thereto.
3. The method of claim 1, wherein the supporting device is a set-up
arm; and the motion of the monitor is sensed by one or more rotary
encoders at one or more joints of the set-up arm supporting the
monitor.
4. The method of claim 1, further comprising: prior to moving the
monitor, grasping sides of the monitor with a pair of hands.
5-15. (canceled)
16. The method of claim 1, wherein moving the monitor further
includes moving a setup arm coupled to a housing of the monitor,
including one or more serial links between the housing and a
mechanical ground; and sensing the motion of the one or more serial
links with one or more motion sensing devices to determine
direction and distance of motion of the monitor.
17. The method of claim 16, wherein the one or more motion sensing
devices are one or more rotary encoders at one or more joints of
the one or more serial links supporting the monitor.
18. The method of claim 1, wherein the robotic surgical tool is an
ultrasound tool.
19. The method of claim 1, wherein the robotic surgical tool is an
endoscopic camera.
20. The method of claim 19, wherein the motion of the endoscopic
camera mechanically pans a center of a video frame displayed on the
monitor.
Description
FIELD
[0001] The embodiments of the invention relate generally to vision
subsystems for minimally invasive robotic surgical systems.
BACKGROUND
[0002] Minimally invasive surgical (MIS) procedures have become
more common using robotic (e.g., telerobotic) surgical systems. An
endoscopic camera is typically used to provide images to a surgeon
of the surgical cavity so that the surgeon can manipulate robotic
surgical tools therein.
[0003] A surgeon's focus is typically on the tissue or organs of
interest in a surgical cavity. He may manually move the endoscopic
camera in and around a surgical site or cavity to properly see and
manipulate tissue with robotic surgical tools. However, when the
endoscopic camera is manually moved inward so that tissue is at
desired magnifications, typically a narrow field of view is
provided of the surgical cavity by the endoscopic camera. Tools or
tissue that are outside the field of view typically require the
surgeon to manually cause the endoscopic camera to move to a
different position or manually move the camera back out.
[0004] Some times the endoscopic camera is slightly moved left,
right, up, and/or down to see a slightly different view or slightly
moved out to obtain a slightly larger field of view and then moved
right back to the original position to the desired magnification to
manipulate tissue.
[0005] Some times a surgeon may have to initially guess which
direction to move the endoscopic camera to position the tissue
and/or tool of interest in the surgical cavity within the field
view of the endoscopic camera.
[0006] A more efficient use of the endoscopic camera may also make
surgical procedures with a robotic surgical system more
efficient.
BRIEF SUMMARY
[0007] The embodiments of the invention are summarized by the
claims that follow below.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0008] FIG. 1A is a block diagram of a robotic medical system
including a stereo viewer and an image guided surgery (IGS) system
with a tool tracking sub-system.
[0009] FIG. 1B is a block diagram of a patient side cart including
robotic surgical arms to support and move robotic instruments.
[0010] FIG. 1C is perspective view of an endoscopic camera
manipulator or robotic surgical arm.
[0011] FIG. 2 is a functional block diagram of the video portion of
the IGS system to provide a stereo image in both left and right
video channels to provide three-dimensional images in a stereo
viewer.
[0012] FIG. 3 is a perspective view of a robotic surgical master
control console including a stereo viewer and an IGS system with
tool tracking sub-system.
[0013] FIG. 4A is a cutaway side view of the stereo viewer with
gaze detection in the robotic surgical master control console.
[0014] FIG. 4B is a perspective view of the stereo viewer with gaze
detection in the robotic surgical master control console.
[0015] FIG. 4C is a side view of the stereo viewer with gaze
detection in the robotic surgical master control console.
[0016] FIG. 5A is perspective view of a video frame including video
images of a surgical site with a navigation window.
[0017] FIG. 5B is a schematic view of the video frame including
video images of a surgical site with a navigation window.
[0018] FIG. 6A is a perspective view of a video frame including
video images of a surgical site with a digital zoomed fovea
portion.
[0019] FIG. 6B is an exemplary illustration of a linear mapping
between source pixel information and target pixels for a digitally
zoomed fovea of a display and a non-linear mapping between source
pixel information and target pixels for a background or surround
image portion of the display.
[0020] FIG. 6C is a schematic diagram illustrating of a linear
mapping between source pixel information and target pixels for a
digitally zoomed fovea of a display and a linear mapping between
source pixel information and target pixels for a background or
surround image portion of the display.
[0021] FIG. 6D is a schematic diagram illustrating a mapping
between source pixel information and target pixels of a
display.
[0022] FIG. 6E is a schematic diagram illustrating the inner and
outer source pixel windows of FIG. 6D.
[0023] FIG. 6F is an exemplary illustration of a linear mapping
between source pixel information and target pixels for a digitally
zoomed fovea of a display and a linear mapping between source pixel
information and target pixels for a background or surround image
portion of the display.
[0024] FIGS. 7A-7D are diagrams to illustrate combinations of
digital pan and/or mechanical panning of the endoscopic camera of a
frame of a video information with a digital zoom portion in
response to gaze detection.
[0025] FIG. 8 illustrates a gradual movement of the digital zoom
portion over multiple frames of video information.
[0026] FIG. 9 illustrates a face with stereo gaze detection to
detect left and right pupil positions.
[0027] FIG. 10 illustrates left and rights graphs as to how the
position of the pupil may be sensed with respect to the edges of
the eye.
[0028] FIGS. 11A-11B illustrates a face with an upper left gaze
position and a lower right left gaze position, respectively.
[0029] FIG. 12 illustrates how vertical head movement may be
detected.
[0030] FIG. 13 illustrates how a combination of vertical and
horizontal head movement may be detected.
[0031] FIG. 14 illustrates a touch screen user interface in a
display device to provide a control input to control a robotic
surgical instrument such as an endoscopic camera.
[0032] FIG. 15 illustrates manual movement of a display device to
provide a control input to control a robotic surgical instrument
such as an endoscopic camera.
[0033] FIG. 16 is a functional block diagram of a digital video
zoom subsystem to provide digital zoom portion and automatic
panning of video information in a surgical site.
[0034] FIGS. 17A-17B illustrate a perspective view of an image and
automatic panning of a fovea within the image using a tool
centroid.
[0035] FIGS. 18A-18B illustrate a perspective view of an image and
panning a fovea within the image using a robotic surgical tool to
poke the fovea around therein.
DETAILED DESCRIPTION
[0036] In the following detailed description of the embodiments of
the invention, numerous specific details are set forth in order to
provide a thorough understanding of the present invention. However,
it will be obvious to one skilled in the art that the embodiments
of the invention may be practiced without these specific details.
In other instances well known methods, procedures, components, and
circuits have not been described in detail so as not to
unnecessarily obscure aspects of the embodiments of the
invention.
Introduction
[0037] Aspects of the invention include methods, apparatus and
systems for automated panning and digital zooming for video
subsystems of robotic surgical systems.
[0038] High definition endoscopic cameras may generate a greater
number of pixels than can be displayed by liquid crystal display
panels or display monitors. Aspects of some of the disclosed
embodiments of the invention may use some of the extra pixel
information captured by high definition endoscopic cameras that
would otherwise be unused and possibly discarded.
[0039] Automatic camera following, an aspect of some embodiments of
the invention, is disclosed that may be responsive to robotic
surgical instrument location using API information, or selection of
an active area in a surgical site into which the surgeon desires to
gaze.
[0040] A linear digital zoom, another aspect of some embodiments of
the invention, is disclosed that linearly scales a spatial subset
of a source of high definition video images on one or more
displays. The full spatial high definition video images may be
linearly scaled down or down-sampled and displayed
picture-in-picture (PIP) as a navigation window or a pull-back view
for example.
[0041] On the same display device, a linear digital zoom of a
spatial subset of the source the high definition video images may
combined with a non-linear digital zoom of another spatial subset
of the source of the high definition video images, in some
embodiments of the invention. A first spatial subset of the source
of the high definition video images may be digitally zoomed
linearly and displayed or rendered in a target window portion
(fovea) on a display device and concurrently a second spatial
subset of the source of the high definition video images around the
first spatial subset may be digitally zoomed non-linearly and
displayed or rendered in a target frame portion (background or
surround) around the target window portion (fovea) on the display
device to provide a smooth image transition.
[0042] The frame portion (background or surround) with the second
spatial subset of the source of the high definition video images
altered by a non-linear digital zoom factor may be used to complete
the surgeon's field of view around the window portion (fovea). In
one configuration of the invention, the target window portion
(fovea) may be displayed in high-resolution while the frame portion
(background or surround) is displayed with a lower-resolution to
provide an improved sense of peripheral vision. With an improved
sense of peripheral vision, the need for a PIP navigation window of
the surgical site displayed on the display monitor is reduced. The
frame portion (background or surround) with the non-linear digital
zoom may reduce the number of otherwise frequent short duration
camera control events. Short duration camera control events are
adjustments in the endoscopic camera that are often made due to a
surgeon's desire to see what is just-outside-the-field-of-view or
in reaction to lack of peripheral vision, rather than adjustments
made to obtain a better field of view of the operative site.
[0043] Automatic camera following may be combined together with a
digital zoom in some embodiments of the invention such that the
digital zoomed portion of an image tracks or follow a surgeon's
motions, such as the gaze of his pupils, without requiring
mechanical movement of the endoscopic camera. If the surgeon's
motions indicate that the digital zoomed portion extend beyond
pixels of the high definition digital image being captured, the
endoscopic camera may be mechanically moved or panned
automatically.
[0044] For automatic camera following, different sensing modalities
may be used to detect a surgeon's motion so that a digital zoomed
portion of interest of an image may be moved around within the
pixels of a high definition digital image. Some different sensing
modalities include (1) robotic surgical tool tracking, (2) surgeon
gaze tracking; (3) or a discrete user interface. Robotic surgical
tool tracking may be performed by kinematics sensing through joint
encoders, potentiometers, and the like; video analysis-based tool
location tracking; or a combination or fusion of kinematics sensing
and video analysis-based tool location tracking. A discrete user
interface may include one or more of button actuation (such as
arrow buttons to the side of a surgeon's console), button presses
of master console handle buttons, foot-pedal presses, or voice
recognition activation. The discrete user interface may be used to
re-center the digital zoomed image based on current tool position,
gaze location, or the like. Alternatively, the discrete user
interface may be used to re-center or move the image at discrete
times, such as through voice activation, perhaps in concert with
tool tracking or gaze detection.
Robotic Medical System
[0045] Referring now to FIG. 1A, a block diagram of a robotic
surgery system 100 is illustrated to perform minimally invasive
robotic surgical procedures on a patient P on an operating table T
using one or more robotic arms 158A-158C (collectively referred to
as robotic arms 158). The one or more robotic arms often support a
robotic instrument 101. For instance, a robotic surgical arm (e.g.,
the center robotic surgical arm 158B) may be used to support a
stereo or three-dimensional surgical image capture device
(endoscopic camera) 101B such as a stereo endoscope (which may be
any of a variety of structures such as a stereo laparoscope,
arthroscope, hysteroscope, or the like), or, optionally, some other
imaging modality (such as ultrasound, fluoroscopy, magnetic
resonance imaging, or the like).
[0046] Robotic surgery may be used to perform a wide variety of
surgical procedures, including but not limited to open surgery,
neurosurgical procedures (e.g., stereotaxy), endoscopic procedures
(e.g., laparoscopy, arthroscopy, thoracoscopy), and the like.
[0047] A user or operator O (generally a surgeon) performs a
minimally invasive surgical procedure on patient P by manipulating
control input devices (touch sensitive master control handles) 160
at a master control console 150. A computer 151 of the console 150
directs movement of robotically controlled endoscopic surgical
instruments (robotic surgical tools or robotic instruments)
101A-101C via control lines 159, effecting movement of the
instruments using a robotic patient-side system 152 (also referred
to as a patient-side cart). In a stereo display device 164 of the
master control console 150, the operator O views video images of
the surgical site including the robotic surgical tools that are in
the field of view of the endoscopic camera 101B.
[0048] The robotic patient-side system 152 includes one or more
robotic arms 158. Typically, the robotic patient-side system 152
includes at least three robotic surgical arms 158A-158C (generally
referred to as robotic surgical arms 158) supported by
corresponding positioning set-up arms 156. The central robotic
surgical arm 158B may support an endoscopic camera 101B. The
robotic surgical arms 158A and 158C to the left and right of center
may support robotic instruments 101A and 101C, respectively, that
may manipulate tissue.
[0049] Robotic instruments (robotic surgical tools) are generally
referred to herein by the reference number 101. Robotic instruments
101 may be any instrument or tool that couples to a robotic arm
that can be manipulated thereby and can report back kinematics
information to the robotic system. Robotic instruments include, but
are not limited to, surgical tools, medical tools, bio-medical
tools, and diagnostic instruments (ultrasound, computer tomography
(CT) scanner, magnetic resonance imager (MRI)).
[0050] Generally, the robotic patient-side system 152 includes a
positioning portion and a driven portion. The positioning portion
of the robotic patient-side system 152 remains in a fixed
configuration during surgery while manipulating tissue. The driven
portion of the robotic patient-side system 152 is actively
articulated under the direction of the operator O generating
control signals at the surgeon's console 150 during surgery. The
driven portion of the robotic patient-side system 152 may include,
but is not limited or restricted to robotic surgical arms
158A-158C.
[0051] The instruments 101, the robotic surgical arms 158A-158C,
and the set up joints 156,157 may include one or more displacement
transducers, positional sensors, and/or orientational sensors
185,186 to assist in acquisition and tracking of robotic
instruments. From instrument tip to ground (or world coordinate) of
the robotic system, the kinematics information generated by the
transducers and the sensors in the robotic patient-side system 152
may be reported back to a tracking system 352 of the robotic
surgical system.
[0052] As an exemplary embodiment, the positioning portion of the
robotic patient-side system 152 that is in a fixed configuration
during surgery may include, but is not limited or restricted to
set-up arms 156. Each set-up arm 156 may include a plurality of
links and a plurality of joints. Each set-up arm may mount via a
first set-up-joint 157 to the patient side system 152.
[0053] An assistant A may assist in pre-positioning of the robotic
patient-side system 152 relative to patient P as well as swapping
tools or instruments 101 for alternative tool structures, and the
like, while viewing the internal surgical site via an external
display 154. The external display 154 or some other external
display may be positioned or located elsewhere so that images of
the surgical site may be displayed to students or other interested
persons during a surgery. Images with additional information may be
overlaid onto the images of the surgical site by the robotic
surgical system for display on the external display 154.
[0054] Referring now to FIG. 1B, a perspective view of the robotic
patient-side system 152 is illustrated. The robotic patient-side
system 152 comprises a cart column 170 supported by a base 172. One
or more robotic surgical arms 158 are respectively attached to one
or more set-up arms 156 that are a part of the positioning portion
of robotic patient-side system 152. Situated approximately at a
central location on base 172, the cart column 170 includes a
protective cover 180 that protects components of a counterbalance
subsystem and a braking subsystem (described below) from
contaminants.
[0055] Excluding a monitor arm 158E for the monitor 154, each
robotic surgical arm 158 is used to control robotic instruments
101A-101C. Moreover, each robotic surgical arm 158 is coupled to a
set-up arm 156 that is in turn coupled to a carriage housing 190 in
one embodiment of the invention, as described below with reference
to FIG. 3. The one or more robotic surgical arms 158 are each
supported by their respective set-up arm 156, as is illustrated in
FIG. 1B.
[0056] The robotic surgical arms 158A-158D may each include one or
more displacement transducers, orientational sensors, and/or
positional sensors 185 to generate raw uncorrected kinematics data,
kinematics datum, and/or kinematics information to assist in
acquisition and tracking of robotic instruments. The robotic
instruments may also include a displacement transducer, a
positional sensor, and/or orientation sensor 186 in some
embodiments of the invention. Moreover, one or more robotic
instruments may include a marker 189 to assist in acquisition and
tracking of robotic instruments.
Robotic Surgical Arms
[0057] Referring now to FIG. 1C, a perspective view of the robotic
surgical arm 158B is illustrated. As discussed previously, the
center robotic surgical arm 158B is for coupling to an endoscopic
camera 101B. The endoscopic camera 101B may not have an end
effector that requires controlling. Thus, fewer motors, cables, and
pulleys may be employed in controlling the endoscopic camera 101B.
However for the purposes of overall movement (e.g., pitch, yaw, and
insertion), the elements of the center robotic surgical arm 158B
are similar to the elements of the robotic surgical arms
158A,158C.
[0058] In robotic surgical systems for minimally invasive surgery,
it is desirable to move and constrain a robotic surgical tool at a
single fixed remote center point 556. Typically the fixed remote
center point 556 is near the point of insertion of the surgical
tool into the patient P. The center of rotation 556 may be aligned
with the incision point to the internal surgical site, for example,
by a trocar or cannula at an abdominal wall during laparoscopic
surgery. As the fixed remote center point 556 is on the insertion
axis 574 of the robotic camera and is offset and remote from
ground, the robotic surgical arm may also be referred as an offset
remote center manipulator instead.
[0059] The robotic surgical arm 158B includes serial links 541-545
pivotally coupled in series at joints 512-514 near respective ends
of the links. The first link (Link 1) 541 is pivotally coupled to a
drive mount 540 at a first joint 511 near a first end and the
second link (Link 2) 542 at the second joint 512 near a second end.
The third link (Link 3) 543 is pivotally coupled to the second link
542 near a first end and pivotally coupled to the fourth link (Link
4) 544 near a second end. Generally, the fourth link 544 is
substantially in parallel to the insertion axis 574 of the
endoscopic camera 101B. A fifth link (Link 5) 545 is slidingly
coupled to the fourth link 544. The endoscopic camera 101B mounts
to the fifth link 545 as shown.
[0060] The robotic surgical arm 158B further includes a mounting
base 540 that allows it to be mounted and supported by set-up
arms/joints of a patient side system. The mounting base 540 is
pivotally coupled to the first link 541 and includes a first motor
551 to yaw the robotic surgical arm about a yaw axis at the pivot
point. The second link 542 houses a second motor 552 to drive and
pitch the linkage of the arm about a pitch axis at the pivot point
556. The fourth link 544 may include a third motor 553 to slide the
firth link 545 and the endoscopic camera 101B along the insertion
axis 574.
[0061] The robotic endoscopic camera arm 158B and the robotic
surgical arms 158A,158C have a drive train system driven by the
motors 551-553 to control the pivoting of the links about the
joints 512-514. If the endoscopic camera 101B is to be mechanically
moved, one or more of the motors 551-553 coupled to the drive train
are energized to move the links of the robotic endoscopic camera
arm 158B. Other tools 101 attached to the robotic surgical arms
158A,158C may be similarly moved.
Endoscopic Video System
[0062] Referring now to FIG. 2, the stereo endoscopic camera 101B
includes an endoscope 202 for insertion into a patient, a camera
head 204, a left image forming device (e.g., a charge coupled
device (CCD)) 206L, a right image forming device 206R, a left
camera control unit (CCU) 208L, and a right camera control unit
(CCU) 208R coupled together as shown. The stereo endoscopic camera
101B generates a left video channel 220L and a right video channel
220R of frames of images of the surgical site coupled to a stereo
display device 164 through a video board 218. To initially
synchronize left and right frames of data, a lock reference signal
is coupled between the left and right camera control units
208L,208R. The right camera control unit generates the lock signal
that is coupled to the left camera control unit to synchronize the
left view channel to the right video channel. However, the left
camera control unit 208L may also generate the lock reference
signal so that the right video channel synchronizes to the left
video channel.
[0063] The stereo display device 164 includes a left monitor 230L
and a right monitor 230R. As discussed further herein, the
viewfinders or monitors 230L,230R may be provided by a left display
device 402L and a right display device 402R, respectively. The
stereo images may be provided in color by a pair of color display
devices 402L,402R.
[0064] Additional details of a stereo endoscopic camera and a
stereo display may be found in U.S. Pat. No. 5,577,991 entitled
"Three Dimensional Vision Endoscope with Position Adjustment Means
for Imaging Device and Visual Field Mask" filed on Jul. 7, 1995 by
Akui et al; U.S. Pat. No. 6,139,490 entitled "Stereoscopic
Endoscope with Virtual Reality Viewing" filed on Nov. 10, 1997 by
Breidenthal et al; and U.S. Pat. No. 6,720,988 entitled "Stereo
Imaging System and Method for use in Telerobotic Systems" filed on
Aug. 20, 1999 by Gere et al.; all of which are incorporated herein
by reference. Stereo images of a surgical site may be captured by
other types of endoscopic devices and cameras with different
structures. For example, a single optical channel may be used with
a pair of spatially offset sensors to capture stereo images of the
surgical site.
[0065] Referring now to FIG. 3, a perspective view of the robotic
surgical master control console 150 is illustrated. The master
control console 150 of the robotic surgical system 100 may include
a computer 151, a stereo viewer 312, an arm support 314, a pair of
control input wrists and control input arms in a workspace 316,
foot pedals 318 (including foot pedals 318A-318B), and a head
sensor 320. The master control console 150 may further include a
digital zoom/panning system 351 and a tracking system 352 coupled
to the computer 151 for providing the digital zoomed images, fovea
images, and/or PIP images of the surgical site. The tracking system
352 may be a tool tracking system or a surgeon motion tracking
system, such as for gaze detection/tracking, to provide for the
digital panning of the camera images.
[0066] The stereo viewer 312 has two displays where stereo
three-dimensional images of the surgical site may be viewed to
perform minimally invasive surgery. When using the master control
console, the operator O typically sits in a chair, moves his or her
head into alignment with the stereo viewer 312 to view the
three-dimensional images of the surgical site. To ensure that the
operator is viewing the surgical site when controlling the robotic
instruments 101, the master control console 150 may include a head
sensor 320 disposed adjacent the stereo viewer 312. When the system
operator aligns his or her eyes with the binocular eye pieces of
the stereo viewer 312 to view a stereoscopic image of the surgical
worksite, the operator's head activates the head sensor 320 to
enable the control of the robotic instruments 101. When the
operator's head is removed from the area of the stereo viewer 312,
the head sensor 320 is deactivated to disable or stop generating
new control signals in response to movements of the touch sensitive
master control handles 160 in order to hold the state of the
robotic instruments.
[0067] The arm support 314 can be used to rest the elbows or
forearms of the operator O (typically a surgeon) while gripping
touch sensitive master control handles 160 of the control input
wrists, one in each hand, in the workspace 316 to generate control
signals. The touch sensitive master control handles 160 are
positioned in the workspace 316 disposed beyond the arm support 314
and below the viewer 312. This allows the touch sensitive master
control handles 160 to be moved easily in the control space 316 in
both position and orientation to generate control signals.
Additionally, the operator O can use his feet to control the
foot-pedals 318 to change the configuration of the surgical system
and generate additional control signals to control the robotic
instruments 101 as well as the endoscopic camera.
[0068] The computer 151 may include one or more microprocessors 302
to execute instructions and a storage device 304 to store software
with executable instructions that may be used to generate control
signals to control the robotic surgical system 100. The computer
151 with its microprocessors 302 interprets movements and actuation
of the touch sensitive master control handles 160 (and other inputs
from the operator O or other personnel) to generate control signals
to control the robotic surgical instruments 101 in the surgical
worksite. In one embodiment of the invention, the computer 151 and
the stereo viewer 312 map the surgical worksite into the controller
workspace 316 so it feels and appears to the operator that the
touch sensitive master control handles 160 are working over the
surgical worksite. The computer 151 may couple to the digital
zoom/panning system 351 and the tracking system 352 to execute
software and perform computations for the digital zoom/panning
system.
[0069] Referring now to FIG. 4A, a side cutaway view of the
surgeon's master control console 150 is shown to illustrate the
stereo viewer 312 with a gaze detection/tracking system. The stereo
viewer 312 may include a left display 402L and one or more left
gaze detection sensors 420L for the left eye EL of a surgeon and a
right display 402R and one or more right gaze detection sensors
420R (not shown in FIG. 4A, see FIG. 4B) for the right eye of the
surgeon. The head sensor 320 illustrated in FIG. 3 may be used to
enable/disable the gaze detection system so that other motion is
not inadvertently sensed as the surgeon's eye movement.
[0070] FIG. 4C illustrates a magnified side view of the stereo
viewer 312 including the left display 402L and the one or more left
gaze detection sensors 420L for the left eye EL of the surgeon. The
one or more left gaze detection sensors 420L may sense X and Y axes
movement of a pupil PL along a Z optical axis.
[0071] A fixed lens 450 may be provided between each eye and each
respective display device 402L,402R to magnify or adjust the
apparent depth of the displayed images I over a depth range 452.
The focus on an image in the surgical site is adjusted prior to
image capture by a moveable lens in the endoscopic camera 101B that
is in front of the CCD image sensor.
[0072] Referring now to FIG. 4B, a perspective view of the stereo
viewer 312 of the master control console 150 is illustrated. To
provide a three-dimensional perspective, the viewer 312 includes
stereo images for each eye including a left image 400L and a right
image 400R of the surgical site including any robotic instruments
101 respectively in a left viewfinder 401L and a right viewfinder
401R. The images 400L and 400R in the viewfinders may be provided
by a left display device 402L and a right display device 402R,
respectively. The display devices 402L,402R may optionally be pairs
of cathode ray tube (CRT) monitors, liquid crystal displays (LCDs),
or other type of image display devices (e.g., plasma, digital light
projection, etc.). In the preferred embodiment of the invention,
the images are provided in color by a pair of color display devices
402L,402R, such as color CRTs or color LCDs.
[0073] In the stereo viewer 312, three dimensional images of a
navigation window or a fovea may be rendered within the main image
of the surgical site. For example, in the right viewfinder 401R a
right navigation window image 410R may be merged into or overlaid
on the right image 400R being displayed by the display device 402R.
In the left viewfinder 401L, a left navigation window image 410L
may be merged into or overlaid on the left image 400L of the
surgical site provided by the display device 402L.
[0074] If the gaze detection system is used to control the position
of the fovea or the digital panning of the digital zoom image of
the surgical site, the stereo viewer 312 may include one or more
left gaze detection sensors 420L near the periphery of the display
device 402L for the left eye of the surgeon and one or more right
gaze detection sensors 420R near the periphery of the display
device 402R for the right eye of the surgeon. One of the gaze
detection sensors for each eye may also include a low level light
source 422L,422R to shine light into the eye of the surgeon to
detect eye movement with the respective gaze detection sensors
420L,420R.
[0075] While a stereo video endoscopic camera 101B has been shown
and described, a mono video endoscopic camera generating a single
video channel of frames of images of the surgical site may also be
used in a number of embodiments of the invention. Images, such as a
navigation window image, can also be overlaid onto a portion of the
frames of images of the single video channel.
Digital Zoom
[0076] As the endoscopic camera 101B is a digital video camera, it
provides digital pixel information regarding the images that are
captured. Thus, the digital images that are captured may be
digitally zoomed in order to bring the objects closer in into view
in the display of an image. In an alternate embodiment of the
invention, the endoscopic camera 101B may include an optical zoom,
in addition to a digital zoom, to magnify objects prior to image
capture by using mechanical movement of optics, such as lenses.
[0077] In contrast to an optical zoom that involves a movement of
optics, a digital zoom is accomplished electronically without any
adjustment of the optics in the endoscopic camera 101B. Generally,
a digital zoom selects a portion of an image and manipulates the
digital pixel information, such as interpolating the pixels to
magnify or enlarge the selected portion of the image. In other
words, a digital zoom may crop a portion of an image and then
enlarge it by interpolating the pixels to exceed the originally
cropped size. While the cropped image may be larger, a digital zoom
may decrease or narrow an apparent angle of view of the overall
video image. To the surgeon, a digitally zoomed image alone may
have a reduced field of view of the surgical site. Other images may
be provided to compensate for the reduced field of view in the
digitally zoomed image.
[0078] With some embodiments of invention, a region-of-interest is
selected from source video images to undergo a digital zoom. The
selected region of interest is then scaled linearly for
presentation to the display (e.g., as a fovea 650). The region of
interest may be scaled up (interpolated), or scaled down
(decimated), depending on the number of pixels in the source
region-of-interest, relative to the number of pixels allocated (for
this tile of video) on the display. Digital filtering of the source
data is performed as part of the interpolation/decimation process.
Selection of a region-of-interest smaller than the full source
video frame reduces the surgeon's effective field of view into a
surgical site.
[0079] Note that there are four degrees of freedom available to a
digital zoomed image in a rigid endoscope. The embodiments of the
invention may pan a digital zoomed image up, down, left, and/or
right and it may rotate the image and/or change its level of
zoom.
[0080] As discussed previously herein, the endoscopic camera 101B
is a high definition camera. In one embodiment of the invention,
the high definition endoscopic camera 101B has a greater resolution
than the resolution of the display devices 402L,402R. The extra
pixel information from the high definition endoscopic camera 101B
may be advantageously used for digital zoom. The region of interest
selected from the source video need not be mapped one-to-one or
magnified. In fact, a region of interest selected from the source
video may contain more pixels than are allocated on the display for
presentation of the video source. If that is the case, the pixels
in the selected region of interest may be scaled down (decimated),
while still appearing to the user to zoom in on objects.
[0081] Texture mapping, pixel mapping, mapping pixels, or mapping
texture pixels, may be used interchangeably herein as functional
equivalents where a source image is sampled at source coordinates
or points (t_x,t_y) and a target image is colored at target
coordinates or points (v_x,v_y).
[0082] As discussed previously, one aspect of some embodiments of
the invention may be a linear digital zoom while one aspect of some
embodiments of the invention may be a non-linear digital zoom.
[0083] Referring now to FIG. 5A, a perspective view of images 500
in the stereo viewer 312 with a linear digital zoom is illustrated.
A linear digital zoomed view 501 is displayed in a substantial
portion of the display 402L,402R. The linear digital zoomed view
501 may magnify the images of tissue 505 and a right side surgical
tool 510R in the surgical site. Alternatively, the view 501 may be
a spatial subset of high definition images displayed on a portion
of the display 402L,402R.
[0084] Within the linear digital zoomed view 501 may be a
navigation window or pull-back view 502. The navigation window or
pull-back view 502 may be the full spatial high definition image
that has been down-sampled to be displayed picture-in-picture (PIP)
within the smaller display region.
[0085] Referring now to FIG. 5B, a pixel map diagram is illustrated
for the linear digital zoomed view 501 of FIG. 5A. The stereo
endoscopic camera 101B captures left and right high definition
spatial images 510 with a two dimensional array of pixels that is
HDX pixels wide by HDY pixels high. For example, the two
dimensional array of pixels for the high definition spatial images
510 may be 1920 pixels wide by 1080 pixels high.
[0086] However, the display devices 402L,402R in the stereo view
312 may only display low definition images 511N with a
two-dimensional array of pixels with a native resolution of LDX
pixels wide by LDY pixels high that are respectively less than the
available spatial resolution of HDX pixels wide by HDY pixels high
for the high definition spatial images 510. For example, the two
dimensional array of pixels for the low definition spatial images
511N may be 1280 pixels wide (LDX) by 1024 pixels high (LDY) in
contrast to 1920 pixels wide (HDX) by 1080 pixels high (HDY) for
exemplary high definition spatial images 510.
[0087] As the display devices 402L,402R in the stereo viewer 312
display a lower native resolution of LDX pixels wide by LDY pixels
high, some of the pixel information in the full spatial high
definition image 510 may go unused. For example, the position and
relationship between the low definition images 511N and the high
definition images 510 may be fixed. In which case, pixels 521
within the resolution of the low definition image 511N may be
displayed on the display devices 402L,402R while some pixels 520
outside the resolution of the low definition image 511N may not be
displayed. In this case, the display devices may be considered as
providing a field of view of a virtual camera inside the endoscopic
camera.
[0088] The field of view of the virtual camera within the field of
view of the endoscopic camera may be digitally adjusted. That is,
the pixels in the high definition images 510 that are to be
displayed by the display devices 402L,402R may be user selectable.
This is analogous to the low definition image 511N being a window
that can be moved over the array of HDX by HDY pixels of the high
definition spatial image 510 to select an array of LDX by LDY
pixels to display. The window of the low definition image 511N may
be moved in X and Y directions to select pixels in the array of HDX
by HDY pixels of the high definition spatial image 510. The pixels
in the high definition images 510 that are to be displayed by the
display devices 402L,402R may also be digitally manipulated.
[0089] A smaller subset of pixels (SX by SY) in the array of HDX by
HDY pixels of the high definition spatial image 510 may be
respectively selected by a user for magnification into a digital
zoom image 511M. The array of SY pixels high by SX pixels wide of
the digital zoom image 511M may be interpolated with a digital
filter or sampling algorithm into a larger number of pixels of the
array of LDX by LDY pixels to display a magnified image on the
display devices 402L,402R. For example, 840 pixels wide by 672
pixels high may be magnified and expanded to 1280 pixels wide by
1024 pixels high maintaining the same aspect ratio for display,
such as on the display devices 402L,402R.
[0090] While the digital zoom image 511M may be expanded by
interpolation into a larger number of pixels to display a magnified
image, such as image 501 illustrated in FIG. 5A, the image
resolution of the array of HDX by HDY pixels of the high definition
spatial image 510 may decimated or reduced down (down-sampled) to
shrink or demagnify its image to fit into a window array 512 of
reduced pixels RX pixels high by RY pixels wide to be used for the
navigation window 502 illustrated in FIG. 5A. For example, high
definition spatial images 510 with an array of 1920 pixels wide by
1080 pixels high may be decimated by a factor of ten to a
demagnified image array of 192 pixels wide by 108 pixels high.
[0091] While the digital zoom for a portion of the display may have
a linear relationship with the pixels of the full spatial image,
the digital zoom may also have a non-linear relationship with the
pixels of the full spatial image in another portion of the display
device.
[0092] Referring now to FIG. 6A, a perspective view of an image 600
in the stereo viewer 312 with is illustrated. A digital zoomed
portion (fovea) 650 is displayed within a background or surround
portion 651 of the image 600 on the display devices 402L,402R. As
the digital zoomed view 650 may be the focus of the central vision
of a surgeon's eyes and surrounded by the surround 651, the digital
zoomed view 650 may also be referred to as a fovea 650. The digital
zoomed view 650 may be considered to be a virtual image within a
larger image analogous to the virtual camera within the endoscopic
camera.
[0093] In FIG. 6A, the digital zoomed view 650 is moveable around
the display (moveable fovea) and may magnify the images of tissue
605 and surgical tools 610R in the surgical site. In another
configuration, the digital zoomed view or fovea 650 is centrally
fixed in position (fixed fovea) within the center of the display
device (e.g., see FIG. 6B). While the fovea may provide a digitally
zoomed image or view of the surgical site, the background or
surround image 651 may provide an improved sense of peripheral
vision to the surgeon, possibly reducing or eliminating the need
for one or more navigation windows.
[0094] The fovea 650 is formed by a first mapping of first array or
set of source pixel information (source pixels) from the high
definition source video images to a first array or set of pixels in
the display device (target pixels). The surround 651 around the
fovea 650 is formed by a second mapping of a second array or set of
source pixel information (source pixels) from the high definition
source video images to a second array or set of pixels in the
display device (target pixels).
[0095] The second mapping differs from the first mapping. In one
embodiment of the invention, the first mapping is a linear mapping
and the second mapping is a non-linear mapping (e.g., see FIG. 6B).
In another embodiment of the invention, the first mapping and the
second mapping are linear mappings (e.g., see FIG. 6F) but differ
in other ways, such as size and/or resolution. For example, the
digital zoomed view 650 may be a high resolution or high definition
image while the background or surround image 651 is a low
resolution or low definition image.
[0096] The digital zoomed view 650 and the background or surround
portion 651 of the image 600 are displayed in real time to a
surgeon over a continuing series of video frame images on the
displays 402L,402R of the stereo viewer. The images may be
continuously updated to view current tool positions and current
state of the surgical site and any tissue that is being manipulated
therein.
[0097] At its edges, there may be a sharp or gradual transition
from the digital zoomed view 650 to the background or surrounding
image 651. For ease of discussion herein, a sharp or hard edge
between the fovea 650 and the background 651 may be assumed.
[0098] The digital zoomed view 650 may be provided by a linear
digital zoom factor over the given field of view selected by a
surgeon to reduce distortion of the image displayed in the fovea
650. The surround view or image 651 may be provided by a linear
digital zoom factor (linear mapping) or a non-linear digital zoom
factor (non-linear mapping) over the given field of view
selected.
[0099] The size of the digital zoom view 650 within the image 600
may be user selectable by a surgeon at the master control console
150 or by an assistant at the external display 154. That is, a user
may selectively expand or contract the x-axis FX and the y-axis FY
pixel dimensions of the area of the fovea or linear digital zoom
view 650. The digital zoom view 650 may be centered in the display
to be in line with a central gaze of the surgeon's eyes.
Alternatively, a user may selectively position the linear digital
zoom view 650 within different positions on the display within the
image 600 by different user interface means described herein.
[0100] Additionally, the source region-of-interest (source zoom
pixels) selected for the fovea 650 from the high definition source
video images and the source region-of-interest (source background
pixels) selected from the high definition source video images for
the surround 651 may be adjusted by the user. For example, the
source pixels for the background around the fovea 650 may selected
to be a spatial subset of the high definition source images.
Alternatively, the source pixels for the background 651 may be
selected to be a set of source pixels to complete the full spatial
image of the high definition images. With a larger field of view
provided by the background 651 around the fovea 650, a surgeon's
peripheral vision of the surgical site may be improved. This can
help avoid or reduce frequent short duration camera control events
that otherwise may be made due to a desire to see what's just
outside the field of view.
[0101] As discussed previously, the fovea 650 is formed by a first
mapping of array or set of source pixel information (source pixels)
from the high definition source video images to a first array or
set of pixels in the display device (target pixels) and the
surround 651 is formed by a second mapping of a second array or set
of source pixel information (source pixels) from the high
definition source video images to a second array or set of pixels
in the display device (target pixels).
[0102] Referring now to FIG. 6D, mapping functions for the first
and second pixel mappings are determined between coordinates in the
source (texture) 660 and coordinates on the target 670 (e.g.,
display 402L,402R,154). Pixel data is mapped from an inner/outer
pair of source windows 661 to an inner/outer pair of target windows
671.
[0103] The source coordinate system origin 665 is defined to be the
upper left corner of the source frame 660 with positive-x right,
and positive-y down. The inner source window 663 may be defined by
selection of a left-top coordinate (t_iL,t_iT) 667 and a
right-bottom coordinate (t_iR,t_iB) 668. The outer source window
664 may be defined by its left-top coordinate (t_oL,t_oT) 666 and
right-bottom coordinate (t_oR,t_oB) 669. In the parenthetical
coordinate description, the prefix t denotes texture, i/o refers to
inner/outer, and L,T,R,B refers to left, top, right, and bottom,
respectively. The coordinates for the inner source window 663 and
the outer source window 664 may be directly or indirectly and
automatically or manually selected by a user (e.g., surgeon O or
assistant A) in a number of ways.
[0104] The target coordinate system origin 675 is defined to be the
upper left corner of the target frame 670, with positive-x right
and positive-y down. The inner target window 673 is defined by its
left-top coordinate (v_iL,v_iT) 677 and its right bottom coordinate
(v_iR,v_iB) 678. The outer target window 674 is defined by its
left-top coordinate (v_oL,v_oT) 676 and its right-bottom coordinate
(v_oR,v_oB) 679. In the parenthetical coordinate description, the
prefix v denotes vertex, i/o refers to inner/outer, and L,T,R,B
refers to left, top, right, and bottom, respectively. The
coordinates for the inner target window 673 and the outer target
window 674 may also be directly or indirectly and automatically or
manually selected by a user (e.g., surgeon O or assistant A) in a
number of ways.
[0105] Referring now to FIGS. 6D-6E, the region corresponding to
the fovea 650 is simply formed by linearly scaling the source pixel
array 680 of the inner source window 663 from coordinate
(t_iL,t_iT) 667 through coordinate (t_iR,t_iB) 668 into the target
pixel array (fovea) 650 of the inner target window 673 from
coordinate (v_iL,v_iT) 677 through coordinate (v_iR,v_iB) 678.
Constructing the surround region 651 around the fovea 650
remains.
[0106] The task of mapping source pixels in the frame shaped region
681 between the inner source window 663 and the outer source window
664 into target pixels in the frame shaped surround region 651
between the inner target window 673 and the outer target window 674
is more difficult due to the frame like shape of each.
[0107] Referring now to FIG. 6E, the source pixels in the frame
shaped region 681 between the inner source window 663 and outer
source window 664 is subdivided into a number of N rectangular
regions (quads). The N rectangular regions may be eight (8)
rectangular regions, for example. Starting at the upper left hand
corner and working clockwise, the eight rectangular regions may be
formed by coordinates 666,686,667,688; 686,687,683,667;
687,685,692,683; 683,692,693,668; 668,693,669,691; 682,668,691,690;
689,682,690,684; and 688,667,682,689. Values for t_x1, t_x2, t_y1,
and t_y2 in the coordinate (t_x1,t_oT) 686, coordinate (t_x2,t_oT)
687, coordinate (t_oL,t_y1) 688, coordinate (t_oL,t_y2) 689,
coordinate (t_x1,t_oB) 690, coordinate (t_x2,t_oB) 691, coordinate
(t_oR,t_y1) 692, and coordinate (t_oR,t_y2) 693 are determined
which allow the subdivision of the frame shaped surround region 681
into the 8 rectangular regions (quads).
[0108] Referring now to FIGS. 6D-6E, if the source pixels t_oL
through t_oR on top and bottom edges of outer source window 664 are
mapped linearly into the target pixels v_oL through v_oR on top and
bottom edges of outer target window 674, then the values of t_x1
and t_x2 are respectively proportional to the length of the line
segments from pixels v_oL through v_iL and pixels v_oL through v_iR
along top and bottom edges of the outer source window 664, and may
be computed by equations 1 and 2 as follows:
t.sub.--x1=t.sub.--oL+(t.sub.--oR-t.sub.--oL)*((v.sub.--iL-v.sub.--oL)/(-
v.sub.--oR-v.sub.--oL)) (1)
t.sub.--x2=t.sub.--oL+(t.sub.--oR-t.sub.--oL)*((v.sub.--iR-v.sub.--oL)/(-
v.sub.--oR-v.sub.--oL)) (2)
[0109] Similarly, if the source pixels t_oT through t_oB on the
right and left edges of outer source window 664 are mapped linearly
into the target pixels v_oT through v_oB on left and right edges of
outer target window 674, then the values of t_y1 and t_y2 are
respectively proportional to the length of the segments from pixels
v_oT through v_iT, and pixels v_oT through v_iB along left and
right edges of the outer source window 664. Thus, the values of
t_y1 and t_y2 may be computed by equations 3 and 4 as follows:
t.sub.--y1=t.sub.--oT+(t.sub.--oB-t.sub.--oT)*((v.sub.--iT-v.sub.--oT)/(-
v.sub.--oB-v.sub.--oT)) (3)
t.sub.--y2=t.sub.--oT+(t.sub.--oB-t.sub.--oT)*((v.sub.--iB-v.sub.--oT)/(-
v.sub.--oB-v.sub.--oT)) (4)
Thus, the source pixels along the edges of the quads may be mapped
with a predetermined mapping (e.g., equations 1-4) into target
pixels values.
[0110] For each interior pixel point (v_x,v_y) in the surround 651
of each quad of the N quads in the source frame 681, we may perform
an interpolation to map source pixels into respective t_x and t_y
values of the target pixels. The interpolation may be a non-linear
interpolation, such as a bilinear interpolation (BI), or a linear
interpolation, where the selection of the interpolation function is
arbitrary. At larger zoom factors of the fovea 650, a non-linear
interpolation may distort less than a linear interpolation.
[0111] A quad drawn counter-clockwise, has target vertex
coordinates defined as:
[0112] Lower Left: v_L, v_B
[0113] Lower Right: v_R, v_B
[0114] Upper Right: v_R, v_T
[0115] Upper Left: v_L, v_T
and associated source texture coordinates defined as:
[0116] Lower Left: t_LLx, t_LLy
[0117] Lower Right: t_LRx, t_LRy
[0118] Upper Right: t_URx, t_URy
[0119] Upper Left: t_ULx, t_ULy
[0120] For each interior target point v_x,v_y within each quad, the
associated source texture point t_x, t_y is found by interpolation.
With the source texture point or coordinate being known for the
source pixel, the texture of the source texture point can be
sampled using an arbitrary filter function and the target pixel at
the target coordinate can be colored with the sampled value of
texture. That is, the source texture is sampled at coordinate
(t_x,t_y) using a filter function to color the target pixel
(v_x,v_y). The filter function used in the sampling process may be
arbitrarily complicated but consistently used.
[0121] Assuming that a bilinear interpolation (BI) is performed for
each interior pixel point (v_x,v_y) in the surround 651, we may
perform a bilinear interpolation (BI) into respective t_x and t_y
values (generally referred to as t values) which are specified on
the quad boundary by equations 5 and 6 as:
t.sub.--x=BI[v.sub.--x,v.sub.--y;v.sub.--L,v.sub.--T,v.sub.--R,v.sub.--B-
;t.sub.--LLx,t.sub.--LRx,t.sub.--URx,t.sub.--ULx] (5)
t.sub.--y=BI[v.sub.--x,v.sub.--y;v.sub.--L,v.sub.--T,v.sub.--R,v.sub.--B-
;t.sub.--LLy,t.sub.--LRy,t.sub.--URy,t.sub.--ULy] (6)
where t_x and t_y are the interpolated t values at each point
(v_x,v_y); v_L,v_T, v_R,v_B are target boundary coordinates; and
t_LLx,t_LRx,t_URx,t_ULx are the lower-left, lower-right,
upper-right, and upper-left `t` coordinates in x and
t_LLy,t_LRy,t_URy,t_ULy are the lower-left, lower-right,
upper-right, and upper-left T coordinates in y. A bilinear
interpolation (BI) is an interpolating function of two variables on
a regular grid. With the values of t_x1, t_x2, t_y1, and t_y2 being
known from equations 1-4, there are known coordinates 686-692 along
the edges of the outer source window 664 that may be used as known
points for the interpolation within each of the N quads.
[0122] The bilinear interpolation BI( ) may be defined in pseudo
code as:
TABLE-US-00001 BI(v_x,v_y, v_L,v_T,v_R,v_B, t_LL,t_LR,t_UR,t_UL) {
a1 = lerp(v_x, v_L, v_R, t_LL, t_LR); a2 = lerp(v_x, v_L, v_R,
t_UL, t_UR); b1 = lerp(v_y, v_T, v_B, a2, a1); // NOTE: swap a2,a1
due to Y+ downward return(b1); }
with lerp( ) being defined in pseudo code as:
TABLE-US-00002 lerp(v, v1, v2, q1, q2) { return(
q1*((v2-v)/(v2-v1)) + q2*((v-v1)/(v2-v1)) ); }
[0123] A bilinear interpolation (BI) is a well known non-linear
mathematical function. It is non-linear as it is mathematically
proportional to a product of two linear functions such as
(a.sub.1x+a.sub.2) (a.sub.3y+a.sub.4). In this case, the bilinear
interpolation is a combination of multiple linear interpolations
over a grid to smoothly transition images between the inner and
outer areas of interest of the source windows 661 and target
windows 671. The bilinear interpolation results in a quadratic warp
in the surround 651 around the fovea 650.
[0124] For example in FIG. 6E, consider the upper left quad of
source pixels in the source frame 681 and mapping them into upper
left quad of the surround 651. The source texture coordinates
assigned to each of the four vertices of the quad of source pixels
is determined in accordance with equations 1-4 described herein.
For the upper left quad the following mapping of vertices is
determined:
[0125] (t_oL,t_y1) maps to (v_oL,v_y1)
[0126] (t_iL,t_y1) maps to (v_iL,v_y1)
[0127] (t_iL,t_oT) maps to (v_iL,v_oT)
[0128] (t_oL,t_oT) maps to (v_oL,v_oT)
Then the texture coordinate (t_x,t_y) of each pixel interior to the
quad at position (v_x,v_y) is found via bilinear interpolation. The
source texture is sampled at coordinate (t_x,t_y) to color the
pixel (v_x,v_y) with an arbitrary filter function.
[0129] Each of the N quads is similarly processed once the texture
coordinates have been assigned to its vertices. As adjacent quads
have the same texture coordinates assigned to their shared
vertices, the final image appears to be a smooth warp, without
discontinuity across quad-boundaries.
[0130] Referring now to FIG. 6B, the results of a first linear
mapping of a checkerboard pattern into the fovea 650 and a
non-linear mapping (e.g., using bilinear interpolation) of a
checkerboard pattern into eight quads of the surround 651 are
illustrated. Lines in the checkerboard of the source image
illustrated on the display indicate warped pixel information. As
the lines are straight and equidistant in the fovea 650, it is
digitally zoomed without any mapping distortion being added. The
surround 651 experiences some warping as it changes from the
digitally zoomed (magnified) image at the edge of the fovea 650 to
a lower digitally zoomed (magnified) image at the outer edges of
the surround. The warpage in the surround 651 is more noticeable at
the corners of the fovea in the FIG. 6B as indicated in the bending
lines in the checkerboard.
[0131] Instead of a non-linear mapping between source pixels and
the target pixels in the N quads of the source frame 681, a linear
mapping may be used but differs from the linear mapping of pixels
for the fovea 650. The mapping of the source pixels in the source
frame 681 to the target pixels in the surround 651 is piecewise
linear for the N quads if the values of t_x1, t_x2, t_y1, and t_y2
are set as follows:
[0132] t_x1=t_iL;
[0133] t_x2=t_iR;
[0134] t_y1=t_iT;
[0135] t_y2=t_iB;
That is, each of the pixels in the N quads is linearly mapped with
a linear scaling function into pixels in the surround 651.
[0136] Referring now to FIG. 6F, the results of a first linear
mapping of a checkerboard pattern into the fovea 650 and a second
linear mapping (e.g., piecewise linear) of a checkerboard pattern
into eight quads of the surround 651 are illustrated. At relatively
low digital zoom factors for the fovea 650, the surround 651 shows
only nominal warpage. However if a relatively high digital zoom
factor is applied to the fovea 650 to highly magnify objects in the
fovea 650, the surround 651 with no change in digital zoom factor
experiences significant warpage. Thus, it has been determined that
a non-linear mapping between source pixels of the frame 681 to
target pixels in the surround 651 is preferable.
[0137] Note that the resolution of the fovea 650 and the surround
651 depends upon the selection of the relative sizes of the
inner/outer source regions and the selection of the relative sizes
of the inner/outer display or target regions. If a user selects to
digitally zoom the fovea 650, the size of the inner source window
663 is typically decreased by changing a digital zoom factor
magnifying the image in the fovea 650. In this case, the size of
the frame 681 of the source video will change resulting in a change
in the warp of the surround 651 as well.
[0138] With the first and second mappings determined from source to
target for the fovea 650 and the surround 651, various digital
filter methods and resampling algorithms may then be used to sample
the source pixel texture information for interpolation/decimation
into the target pixels of one or more display devices. Exemplary
digital filters that may be used are a box filter, tent filter,
Gaussian filter, sinc filter, and lanczos filter.
[0139] Referring now to FIG. 6C, a schematic diagram illustrates
another linear mapping of source pixels from the high definition
video source images of the endoscopic camera to target pixels of
the display are shown to further explain a linear mapping of the
fovea 650 and a linear mapping of the surround or background
651.
[0140] As discussed previously with reference to FIG. 5B, the high
definition spatial images 510 have a two dimensional array of
pixels that is HDX pixels wide by HDY pixels high. For example, the
two dimensional array of pixels for the high definition spatial
images 510 may be 1920 pixels wide by 1080 pixels high. The display
devices 402L,402R in the stereo viewer 312 may display lower native
resolution images 511N with a two-dimensional array of pixels
having a native resolution of LDX pixels wide by LDY pixels high.
The dimensions LDX pixels wide and LDY pixels high of the lower
native resolution images 511N are respectively less than the
available spatial resolution of HDX pixels wide and HDY pixels high
for the high definition spatial images 510.
[0141] The fovea 650 may be an image having dimensions FX pixels
wide (X-axis pixels) and FY pixels high (Y-axis pixels) of the high
definition image without interpolation or decimation such that
there is no loss of resolution or detail in the display area of
interest to a surgeon. In this case there is a one to one mapping
between pixels of the high definition image and pixels of the lower
resolution display. However, extra pixels to each side of the fovea
650 need to be compressed or decimated down to fewer pixels in the
display.
[0142] For example, the high definition spatial images 510 are 1920
pixels wide (X-axis pixels) by 1080 pixels high (Y-axis pixels) and
the native pixel dimensions of the display (low definition spatial
images 511N) are 1280 pixels wide (X-axis pixels) by 1024 pixels
high (Y-axis pixels). Consider in this case that the fovea 650 is
an image having dimensions of 640 pixels wide (FX) and 512 pixels
high (FY) (Y-axis pixels) to be placed in the center of the
display. An array of 640 pixels wide (X-axis pixels) and 512 pixels
high (Y-axis pixels) in the high definition image 510 is mapped one
to one into the 640 pixels wide (FX) (X-axis pixels) and 512 pixels
high (FY) (Y-axis pixels) in the fovea 650. This leaves 640 pixels
wide (X-axis pixels) in the high definition image 510 to each side
of the fovea to be respectively mapped into 320 pixels wide (X-axis
pixels) to each side of the fovea in the display image 511N
resulting in a two-to-one decimation if the full spatial image is
to be displayed. Thus, a two-to-one decimation or compression in
resolution maps the remaining X-axis pixels of the high definition
image into the remaining X-axis pixels of the background or
surround 651. Continuing with the Y-axis pixels, 284 pixels high
(Y-axis pixels) in the high definition image 510 above and below
the fovea are to be respectively mapped into 256 pixels high
(Y-axis pixels) above and below the fovea in the display image 511N
if the full spatial image is to be displayed. Thus, approximately a
1.1-to-1 decimation or compression in resolution along the Y-axis
maps the remaining Y-axis pixels of the high definition image into
the remaining Y-axis pixels of the background or surround 651. Note
that this assumes a total linear mapping in the surround 651, not a
piece-wise linear in each of N quads, which may not work well in
the corners.
[0143] Note that with the total linear mapping in the surround 651
described with reference to FIG. 6C, the Y-axis compression or
decimation may differ from the X-axis compression or decimation. In
this case, the image in the surround will be distorted by being
compressed differently along the axis with the greater decimation.
In the case of the mappings illustrated by FIGS. 6D-6E, the
source/target windows are defined as a percentage of the
source/target extent. Thus, the raw number of pixels in the
surround 651 differs in X,Y, but the percentage change between the
inner/outer windows is the same resulting in less distortion.
[0144] If the display is a high definition display with the same
resolution of high definition special images of the endoscopic
camera, the background 651 may be displayed at the native
resolution while the fovea 650 is interpolated up to be a magnified
image within its pixel array of FX by FY pixels.
Automatic Digital and Mechanical Image Panning
[0145] In one embodiment of the invention, the fovea 650 may be
fixed in the center of the display image 511N and the center of the
display device. If the outer-source-window is smaller than the
source extent, the inner/outer source windows may be digitally
panned within the source frame. In this manner, inner/outer source
window and the inner/outer target windows are concentric to
minimize distortion in the background/surround 651 around the fovea
650.
[0146] Alternatively in another configuration, the fovea 650 may be
digitally (or electronically) moved within the display image 511N
by various means in response to an automatically sensed signal or a
manually generated signal. That is, the fovea 650 may be digitally
(electronically) panned around within the display image. This may
be accomplished by changing the coordinates defining the fovea 650
in the mapping of source pixels to target pixels in the display. In
this case, the inner/outer source window and the inner/outer target
windows may not be concentric.
[0147] In either case, if an image is digitally panned without any
mechanical panning of the endoscopic camera, the surgeon's
perspective (angle at which the surgical site is viewed) on the
surgical site is unchanged.
[0148] In the case of the moving fovea, if the fovea 650 nears the
edge of the display image 511N, a centralization process may occur
where the pixels of the display image 511N may adjust to position
the fovea 650 more centrally in the display image 511N. Moreover if
the desired location of fovea 650 is outside the matrix of pixels
in the display image 511N, the display image 511N may digitally
adjust its position within the high definition spatial image 510 by
selecting different pixels within the high definition spatial image
510. This is analogous to a virtual camera moving around in the
high definition spatial image 510. In this case, both the fovea 650
and the display image may be digitally (electronically) panned
around within the matrix of pixels of the high definition spatial
image 510.
[0149] In the alternate embodiment of the invention where the fovea
650 is fixed in the center of the display, the source window for
selecting the source of pixel information in the high definition
video source images moves to recenter the source area of interest
within the fovea and the center of the display in a substantially
instantaneous manner.
[0150] Further more, if the desired location of fovea 650 not only
exceeds the pixels in the display image 511N but also the pixels of
the high definition spatial image 510, the endoscopic camera 101B
may be mechanically moved by the motors in the robotic arm 158B to
adjust the field of view of the surgical site in response thereto.
In this case, the fovea 650 and the display image may be digitally
(electronically) panned while the endoscopic camera 101B is
mechanically panned to change the field of view of the surgical
site. In alternate embodiment of the invention, the endoscopic
camera 101B may be slewed slowly both digitally (electronically)
and mechanically (physically) to maintain the source area of
interest substantially centered in the source video frame. If the
source area-of-interest is moved off-center, the endoscopic camera
101B may be mechanically moved and concurrently the source window
may be digitally moved in the opposite direction until the
source-window is re-centered relative to the full-extent of the
source video captured by the endoscopic camera.
[0151] Reference is now made to FIGS. 7A-7D to illustrate digital
panning of images and both digital and mechanical panning.
[0152] In FIG. 7A, an initial fovea position 650A of the fovea 650
is shown centered in an image 702A on a display 402L,402R. The
pixels of image 702A displayed by the display may be centered with
respect to the pixels of a high definition spatial image 700A
providing the endoscopic camera 101B field of view.
[0153] A surgeon or an assistant may desire to move the fovea 650
from the initial fovea position 650A to a different fovea position
650B within the display image 511N or outside the display image
511N but within the high definition spatial image 700A. As mention
previously, a centralization process may occur to select different
pixels in the display image 511N from the high definition spatial
image to position the fovea 650 more centrally in the display image
511N, such as illustrated by the image 702B in FIG. 7B which has a
different matrix of pixels to display on the display 402L,402R.
Within the display image 511N and/or within the high definition
spatial image 700A, the fovea 650 is digitally moved from a first
fovea position 650A displaying a first area of the surgical site to
a second fovea position 650B displaying a second area of the
surgical site.
[0154] In FIG. 7B, the fovea position 650B is once again centered
within the image 702B that is displayed on the display 402L,402R.
However, a surgeon or an assistant may desire to move the fovea 650
from the centered fovea position 650B in FIG. 7B to a different
fovea position 650C outside of the display image 511N and the field
of view of the surgical site captured by the high definition
spatial image 700A corresponding to a given position of the
endoscopic camera 101B. In this case, the endoscopic camera 101B
may be mechanically panned to a different position to capture a
different high definition spatial image to display pixels of the
desired fovea position 650C.
[0155] The camera control system of the robotic surgical system may
first move the fovea digitally. If the user out-paces the
compensation rate of re-centering the fovea digitally, the camera
control system transitions/ramps to full endoscopic camera drive
for the motors of the robotic surgical arm 101B to mechanically
move the endoscopic camera. This may happen as the as the user
out-paces the compensation rate of the slow re-centering loop that
is attempting to keep the zoomed region-of-interest centered in the
video frame.
[0156] Note that moving an inner source window relative to an outer
source window changes which pixels are mapped to the inner target
window. If the source frame region between the inner and outer
source windows is being mapped to a surround on the target display,
then moving the inner source window may also change the warp of the
pixels that are mapped to the surround. For example, in the
surround the number of pixels may expand on one side while
contracting on the opposite side.
[0157] As mentioned previously, the fovea 650 may be digitally
moved from the first fovea position 650A to the second fovea
position 650B within the display image 511N and/or within the high
definition spatial image 700A. The fovea 650 may be digitally moved
abruptly from the first fovea position 650A in one video frame to
the second fovea position 650B in the next video frame.
Alternatively, the fovea 650 may be digitally moved gradually from
the first fovea position 650A to the second fovea position 650B
over a sequence of video frames with intermediate fovea positions
there-between.
[0158] Referring now to FIG. 8, the first fovea position 650A and
the second fovea position 650B are illustrated with a plurality of
intermediate fovea positions 850A-850D there-between. In this
manner, the fovea 650 may appear to move more gradually from the
first fovea position 650A to the second fovea position 650B within
the display image 511N and/or within the high definition spatial
image 700A.
[0159] Referring now to FIG. 7C, not only may the display image
511N be digitally panned but the endoscopic camera 101B be
mechanically panned. Additionally, a centering process that further
adjust the digital panning of pixels and/or the mechanical panning
of the endoscopic camera 101B may be used to adjust the display
image 511N to an image position 702C around the fovea in order to
center the desired fovea position 650C therein. In some cases, the
centering process may be undesirable.
[0160] In FIG. 7D, the endoscopic camera 101B may be mechanically
panned and the display image 511N may be digitally panned to a
image position 702D but without any centering process so that the
desired fovea position 650C is off-center within the display
402L,402R.
[0161] FIGS. 7C-7D illustrate combining digital image panning
(digital tracking) with mechanical camera panning (servo-mechanical
tracking). The digital image panning (digital tracking) can be
combined with the mechanical camera panning (servo-mechanical
tracking) analogous to a micro/macro mechanism or system. The
digital image panning (digital tracking) makes the relatively small
and faster deviations or tracking efforts--digital in this case.
The mechanical camera panning (servo-mechanical tracking) can
handle larger deviations that occur more slowly. Note that the
effect of servo mechanical motion of the robotic surgical arm 101B
and the endoscopic camera 101B may be compensated. The zoomed image
or fovea 650 may be moved in the opposite direction of the movement
of the endoscopic camera across the full special high definition
image. In this case, the motion of the endoscopic camera 101B may
be largely imperceptible when viewed in the zoomed image or fovea
650.
[0162] While automatic panning of the endoscopic camera 101B is
possible, it may be preferable to avoid it and use digital panning
alone. Otherwise, the endoscopic camera 101B may bump into
something it should not unless precautions in its movement are
taken. In this case, it is more desirable to digitally pan the
fovea 650 from one position to another without requiring movement
of the endoscopic camera.
Automatic Camera Following and Manual Selection of Image
Position
[0163] In some embodiments of the invention, it may be desirable to
have the image of the fovea or digital zoom area 650 automatically
track or follow some direct or indirect motions of the surgeon
without moving the endoscopic camera 101B. In other embodiments of
the invention, it may be desirable to select the position of the
fovea or digital zoom area 650 within the background image 651 of
the display. In still other embodiments of the invention, it may be
desirable combine characteristics of an automatic tracking system
with a manual selection system such as by setting preferences or
making a choice regarding the fovea or digital zoom area 650 and
allow it to track a surgeon's motion in response thereto.
[0164] Automatic camera following and digital zoom are combined
together such that the digital zoomed portion of an image tracks or
follow a surgeon's motions, such as the gaze of his pupils, without
requiring mechanical movement of the endoscopic camera. If the
surgeon's motions indicate that the digital zoomed portion extend
beyond pixels of the high definition digital image being captured,
the endoscopic camera may be mechanically moved automatically.
[0165] For automatic camera following, different sensing modalities
may be used to detect a surgeon's motion so that a digital zoomed
portion of interest of an image may be moved around within the
pixels of a high definition digital image. Some different sensing
modalities include (1) robotic surgical tool tracking, (2) surgeon
gaze tracking; (3) or a discrete user interface.
[0166] Robotic surgical tool tracking may be performed by
kinematics sensing through joint encoders, potentiometers, and the
like; video analysis-based tool location tracking; or a combination
or fusion of kinematics sensing and video analysis-based tool
location tracking. Robotic surgical tool tracking is further
disclosed in U.S. patent application Ser. No. 11/130,471 entitled
METHODS AND SYSTEM FOR PERFORMING 3-D TOOL TRACKING BY FUSION OF
SENSOR AND/OR CAMERA DERIVED DATA DURING MINIMALLY INVASIVE ROBOTIC
SURGERY filed by Brian David Hoffman et al. one May 16, 2005, which
is incorporated herein by reference and in U.S. patent application
Ser. No. 11/865,014 entitled METHODS AND SYSTEMS FOR ROBOTIC
INSTRUMENT TOOL TRACKING filed by Wenyi Zhao et al. on Sep. 30,
2007, which is also incorporated herein by reference.
[0167] Referring now to FIGS. 17A-17B, a centroid (tool centroid)
1701 for the robotic surgical tools 510L,510R may be determined
from the respective position information points 1710L,1710R within
the surgical site determined from a tool tracking system. The tool
centroid 1701 may be used as a center point to automatically
position the center of the fovea 650 (re-center) within the image
511N.
[0168] For example, the robotic surgical tool 510R may shift in the
surgical site to a position indicated by the robotic surgical tool
510R'. The position information follows the change in position of
the tool to the respective position information point 1710R'. A new
position of tool centroid 1701' is determined given the position
information points 1710L,1710R'. This makes the fovea 650
off-center from the new position of the tool centroid 1701'. The
new position of the tool centroid 1701' may be used as a center
point to automatically re-center the fovea 650 within the image
511N.
[0169] FIG. 17B illustrates the fovea 650 re-centered within the
image 511N in response to the new position of the tool centroid
1701'.
[0170] A discrete user interface may be provided to a surgeon at
the master control console to control the position of the fovea 650
within the image 511N of the display. One or more buttons (such as
arrow buttons to the side of a surgeon's console), one or more foot
pedals, or the master control handles 160 themselves may be used to
manipulate the position of the fovea 650 or other image. A voice
recognition system at the master control console capable of
recognizing vocal commands may also be used to adjust the position
of the fovea 650.
[0171] One or more buttons, foot pedals, or combinations thereof
may be pressed to manually move the fovea 650 or other images up,
down, left, and/or right. Voice commands may be used in another
configuration to move the fovea 650 or other images up, down, left,
and/or right.
[0172] Alternatively, the discrete user interface may be used to
actuate an automatic re-centering process of the digital zoomed
image 650 based on current tool position, gaze location, or other
available information in the surgical system. Alternatively, the
discrete user interface may be used to re-center or move the image
at discrete times, such as through voice activation, perhaps in
concert with tool tracking or gaze detection.
[0173] As mentioned herein, the master control handles 160
themselves may be used to manipulate the position of the fovea 650
or other image. In such a case, one or both, of the master control
handles 160 can serve as a two-dimensional or three-dimensional
mouse (masters-as-mice). Accordingly, one or both of the master
control handles 160 can be arranged to perform functions relative
to the fovea image 650 in a manner analogous to a conventional
mouse relative to a computer screen.
[0174] Each of the master control handles 160 may have at least six
degrees of freedom of movement. Accordingly, when used as a
three-dimensional mouse, a master control handle can be arranged to
control six variables, for example. Therefore, functions such as,
shifting, rotating, panning, tilting, scaling, and/or the like, can
be performed simultaneously when one, or both, or either, of the
masters are used as a three-dimensional mouse, without another
input being required. In particular, for two-handed or two-master
operation, any windows or overlays can be handled as "elastic"
bodies, such that resizing, scaling, warping, and/or the like, can,
for example, be controlled by pulling the masters apart, or the
like.
[0175] One or both of the master control handles 160 may select and
drag the fovea to different positions within the image 511N, either
by adjusting its size/position within the image 511N, and/or by
defining a crop rectangle to generate the fovea 650 from the
background image 651 representative of the full spatial high
definition images. The masters-as-mice functionality of the master
control handles 160 can support successive refinement of the
position of the fovea as well as control the level of image
magnification or zoom within the high definition images.
[0176] In yet another configuration, the robotic surgical tools may
be used to drag the fovea 650 to different positions within the
image 511N and/or move the image 511N within the matrix of pixel
information of the high definition images.
[0177] Referring now to FIG. 18A, robotic surgical tool 510R has a
position information point 1810 well away from the edge and closer
to center of the fovea 650. A tool tracking system may be used to
provide the information regarding the position information point
1810R of the robotic surgical tool relative to the endoscopic
camera 101B. A surgeon may desire to move the fovea 650 within the
image 511N to better magnify a different location within the
surgical site. In this case, the robotic surgical tool 510 may act
as a poker to poke or bump an edge of the fovea 650 to move up,
down, left, right, and/or combinations thereof within the image
511N.
[0178] In an alternate embodiment of the invention with the fovea
650 in a fixed position in the center of the display, an elastic
wall or other haptic interface may be simulated such that when the
robotic surgical tool bumps into the outer edge of the fovea, or
outer edge of the target window, the center position of the source
area-of-interest pans accordingly to be within the fovea 650.
[0179] In FIG. 18A, the robotic surgical tool 510R has moved in
position to robotic surgical tool position 510R' with the position
information point 1810R' near the edge of the fovea 650. The
digital zoom/panning system may pan the fovea 650 in response to
the robot surgical tool being in the robotic surgical tool position
510R' with the position information point 1810R' substantially near
the edge of the fovea 650.
[0180] Referring now to FIG. 18B, the fovea 650 has panned from its
position in FIG. 18A to the fovea position 650' so that the robotic
surgical tool position 510R' and position information point 1810R'
are more centered within the fovea. However, a surgeon may desire
to move from the fovea position 650' to another position. In this
case, the surgeon may use the robotic surgical tool again to pan
the fovea 650. The robotic surgical tool 510R has moved in position
from the robotic surgical tool position 510R' to the robotic
surgical tool position 510R'' with the position information point
1810R'' near the top edge of the fovea 650. In this case, the fovea
650 will be panned up from its position 650'' in FIG. 18B so that
the robotic surgical tool position 510R'' and position information
point 1810R'' will be more centered within the fovea.
[0181] One or more of the manual user interface techniques may be
combined with an automatic user interface technique for digital
panning/zooming.
Gaze Detection and Tracking
[0182] One of the sensing modalities that may be used for automatic
camera following or image panning is gaze tracking of a surgeon's
eyes in the stereo viewer 312.
[0183] As described with reference to FIGS. 4A-4C, the stereo
viewer 312 may include one or more left gaze detection sensors 420L
near the periphery of the display device 402L for the left eye of
the surgeon and one or more right gaze detection sensors 420R near
the periphery of the display device 402R for the right eye of the
surgeon. One of the gaze detection sensors for each eye may also
include a low level light source 422L,422R to shine light into the
eye of the surgeon to detect eye movement with the respective gaze
detection sensors 420L,420R.
[0184] The one or more left gaze detection sensors 420L and the one
or more right gaze detection sensors 420R are used to determine the
location of the central gaze of the surgeon's eyes within the image
that is displayed on the display devices 402L,402R respectively.
The central gaze location within the image may be used to define
the center point of the fovea 650 within the image 511N. As the
surgeon's gaze moves around with the image 511N, the fovea 650 may
digitally move as well to provide a magnified image where the
surgeon is gazing. Moreover, if the surgeon gazes in a location for
a predetermined period of time, that area of the image may be
digitally and/or mechanically automatically re-centered within the
image 511N on the display devices 402L,402R. If instead the fovea
650 is in a fixed position in the center of the display, the
surgeon's gaze off center of the image 511N for a predetermined
period of time may shift the source area of interest to be in the
center of the display within the fovea 650.
[0185] Exemplary algorithms for gaze detection and tracking are
described in detail in "Gaze Contingent Control for Minimally
Invasive Robotic Surgery" by Mylonas G. P., Darzi A, Yang G-Z.
Computer Aided Surgery, September 2006; 11(5): 256-266; "Visual
Search: Psychophysical Models and Practical Applications" by Yang
G-Z, Dempere-Marco L, Hu X-P, Rowe A. Image and Vision Computing
2002; 20:291-305; and "Gaze Contingent Depth Recovery and Motion
Stabilisation for Minimally Invasive Robotic Surgery" by George P.
Mylonas, Ara Darzi, Guang-Zhong Yang; MIAR 2004, LNCS 3150, pp.
311-319, 2004. Exemplary algorithms for gaze detection and tracking
are also described in U.S. Pat. No. 5,912,721 which is incorporated
herein by reference.
[0186] The digitally formed fovea 650 and the digital panning of
the fovea within the image 511N in response to gaze detection,
allows the endoscopic camera 101B to remain stationary, at least
for small adjustments. The automatic digital panning of the fovea
650 with the full spatial high definition image of the endoscopic
camera in the background 651, a surgeon is less likely to be
interrupted during surgery to change the view of images. That is,
with the automatic digital panning of the fovea 650 and the full
spatial high definition image in the background 651, a surgeon may
avoid having to change the view of the surgical site by manual
manipulation of the robotic arm 101B and the endoscopic camera. A
decrease in surgeon interruption to change the view and manipulate
the camera can improve the efficiency of the robotic surgical
system.
[0187] Referring now to FIG. 9, a face is illustrated with stereo
gaze detection about the left and right eyes to detect left and
right pupil positions for gaze detection. The sensors may sense the
pupil positions with respect to the left, right, top, and bottom
edges of the eye. In FIG. 9, a surgeon may initially gaze directly
ahead at a test pattern to calibrate the gaze detection system with
left and right eyes gazing to a center position.
[0188] In contrast with the center position of FIG. 9, FIG. 11A
illustrates left and right eyes gazing to an upper left position.
FIG. 11B illustrates left and right eyes gazing to a lower right
position.
[0189] The gaze of the pupils can be detected in a number of
different ways. FIG. 10 illustrates exemplary left and rights
graphs 1002L,1002R as to how the edges of the pupil may be sensed
with respect to the top, bottom, left, and right corners 1001T,
1001B, 1001L, 1001R of the left and right eyes 1000R, 1000L.
[0190] The edge images for the right eye and left eye of may be
formed via known methods, such as a Sobel filter or a Canny filter.
The edge images can then be mapped in a direction perpendicular to
the one-dimensional (1D) axis direction to detect the inner corners
of the eyes. The image can then be scanned in a direction normal to
the 1D-axis, with the lowest brightness point being the point of
the inner corner of the eye. The peaks in the brightness points on
the graphs 1002L,1002R may indicate the position of the edges of
the left and right pupils.
[0191] As the pupils move horizontally left or right, the position
of the peaks along the graphs 1002R, 1002L shift respectively left
or right. Similar graphs may be generated for vertical movement of
the pupils up and down.
[0192] It may be desirable to detect head movement within the
stereo viewer 312 for a more accurate gaze detection system. Head
movement may be detected by one or more head motion sensors or
algorithmically by using one or more gaze detection sensors
420L,420R. The level of head motion detected may be removed from
gaze detection signals so that inadvertent head movement does not
result in movement of the fovea 650 within the image 511N.
[0193] Referring now to FIG. 12, vertical head movement illustrated
by arrow A may be detected by monitoring the movement of a line
1200 formed through the corners 1001L, 1001R of the left and right
eyes. The corners of the left and right eyes may be determined from
the edge images of the eyes.
[0194] Referring now to FIG. 13, a combination of vertical and
horizontal head movement may be detected using at least two corners
1001T, 1001B, 1001L, 1001R of the left and right eyes. The top
corner 1001T and the left corner 1000L of the right eye 1000R and
the top corner 1001T and the right corner 1000R of the left eye
1000L may be used to form a polygon having a centroid. The centroid
moves along a vector. The corners of the eyes may be monitored to
detect movement in the centroid and the vector so that a
combination of vertical and horizontal head movement may be
detected.
Automatic Zoom Level
[0195] A surgeon may desire additional zoom or magnification of an
object displayed in the fovea 650. Alternatively, the surgeon may
desire less zoom or demagnification of an object displayed in the
fovea 650. The level of the level of zoom may be set by manually by
the selection of relative sizes of the source windows 661 and
target windows 671 illustrated in FIG. 6D. However, methods of
automatically determining an appropriate level of zoom may be made
by automatically determining the relative sizes of the source
windows 661 and target windows 671.
[0196] An approximation for the desired depth of the fovea 650 may
be automatically determined by an average extent of instrument
motion. The average extent may be determined by making a time
weighted average of the motion in the robotic surgical instruments.
Such extent defines a box or area within the image 511N or display
402L,402R. A determination of the minimum zoom that can display the
box or area defined by the extent may be the appropriate level of
zoom to select.
[0197] Gaze detection may also be used to automatically determine
an approximation for the desired depth of the fovea 650. As the
surgeons eyes move over the background 651 in the image 511N, the
gaze motion of the surgeon's pupils or eyes may be stored over
time. A time-weighted average of the stored gaze motion can be
computed to automatically define a two dimensional area or a three
dimensional surface within the image 511N or display 402L,402R. A
determination of the minimum zoom that can display the two
dimensional area or the three dimensional surface defined by the
extent of the gaze motion of the surgeon's eyes may be the
appropriate level of zoom to select.
[0198] In another configuration, the boundary defined by
illumination falloff may be used to automatically select the source
area of interest for display within the fovea 650.
[0199] If an automated digital panning occurs of the fovea 650 or
the image under the fovea 650, the digital zoom may momentarily
zoom out from the area of interest and then zoom back when the area
of interest is substantially centered in the fovea 650.
[0200] A macro/micro approach can also be adapted along the
insertion axis 574 (see FIG. 1C) of the endoscopic camera 101B
mounted on the robotic surgical arm 158B. The endoscopic camera
101B may be physically and mechanically moved in and out of the
surgical site along the insertion axis 574 by the motor 574
providing a macro adjustment. However initially from a fixed
position, if the surgeon wishes to see a slightly narrower field of
view, the camera can be virtually moved in along the insertion axis
toward the tissue by increasing the digital zoom factor providing a
micro adjustment, by decreasing the size of the area-of-interest
selected from the source high definition video images. In this
case, the endoscopic camera is virtually (electronically) moved by
digital signal processing of the source video images without any
physical or mechanical movement.
[0201] When the digital zoom exceeds a predetermined limit or the
source window crosses over a predetermined lower size limit, the
motor 574 may be engaged to physically and mechanically moved the
endoscopic camera 101B along the insertion axis 574 to avoid an
interpolation or a level of interpolation of the pixels (source
pixels) in the source high definition video. This is analogous to
mechanically moving (clutching) the camera along yaw/pitch axes
when the fovea reaches the edge of the high definition video
source. Alternately, endoscopic camera could be slowly adjusted
along the insertion axis both electronically digitally and
physically so as to maintain a source area-of-interest at a
percentage (e.g., approximately 50%) of the source frame size. This
is analogous to a slow slew/auto-recentering of the fovea.
[0202] The zoom factor for the fovea 650 may also be automatically
determined by a distance from the end of the endoscopic camera to
the operative site within the surgical cavity. This is analogous to
auto-focus methods in digital cameras and how they derive an
estimate of the working depth of focus.
Display Panel User Interface
[0203] Much of the discussion regarding digital zooming and digital
panning is with regards to a surgeon O at the controls 160 of the
master console 150. The same images seen by the surgeon in the
stereo viewer may be monitored by an assistant on the external
monitor 154 illustrated in FIGS. 1A-1B. However, the assistant A
may also choose to see a different image than that of the surgeon
without moving the endoscopic camera. The assistant A can control a
second digital zoom and a second digital pan of the captured high
definition digital images from the endoscopic camera 101B so that
they can display a different view of images of the surgical site on
a second display device, the external monitor 154. The assistant A
may control the selection of the second digital zoom and the second
digital pan on the monitor 154 in a number of ways.
[0204] Referring now to FIG. 14, the external monitor 154 may
include a touch screen or touch panel interface 1401 to control the
selection of the second digital zoom and the second digital pan on
the monitor 154. For example, the assistant may touch his finger to
the touch panel 1401 and select a region of the display to be the
target window or fovea 650 with a linear digital zoom. With the
fovea 650 defined and in a fixed position on the display, the
assistant may then use one or more fingers F to scroll the image
under the fovea to display a desired region of interest in the
surgical site captured by the high definition source video images.
Alternatively, a predetermined rectangular shape may be moved over
the image on the touch panel with a finger F to select the desired
region of interest to position within a fovea in the center of the
display monitor 154. With the finger F on the touch panel 1401, the
full frame image may be momentarily displayed on the touch panel
1401 so that the region of interest may be selected and then pop
back out to zoomed-in view with the desired magnification of the
fovea. In these cases, the assistant does not need to mechanically
move the endoscopic camera 101B, avoiding clutching the robotic
surgical arm 158B to physically move the endoscopic camera to
another position.
[0205] Alternatively, one or more control buttons 1404A-1404B may
be provided by the monitor 154 to digitally zoom and magnify the
image provided by the fovea 650 or to digitally move the center of
the fovea to another position within the surgical site. Up, down,
left, and right pan arrows 1406 may be provided to pan the fovea
within the captured pixels of the endoscopic camera to display a
different fovea 650 within the image 511N.
[0206] In another configuration, the assistant may control the
digital pan and the digital zoom for the fovea within the image by
physical movement of the monitor 154. In this case, the monitor may
include an inertia sensor 1450 to detect movement from an initial
position 154A to various different positions such as positions
154B-154C illustrated in FIG. 15. For example, the inertia sensor
1450 may detect movement in the X and Y-axes to pan the fovea 650
around the image 511N displayed on the monitor 154. The inertia
sensor 1450 may detect movement in the Z axis to zoom the fovea 650
in and out of the image 511N displayed on the monitor 154, for
example.
[0207] Referring now to FIG. 15, a support arm 1501 includes a
plurality of links 1505 to moveably support the monitor 154 coupled
to the side cart 152. At a plurality of joints 1512 between the
links 1505, the support arm includes a plurality of encoders 1510
in accordance with another embodiment of the invention.
[0208] In this case, the position of the monitor 154 is determined
by the encoders 1510. The assistant may physically move the monitor
154 by grabbing it with their hands H1-H2. The movement in the
monitor is translated to the joints through the links of the
support arm 1501 and sensed by the encoders 1510. The encoders 1510
can detect movement from an initial position 154A to various
different positions of the monitor 154 such as positions 154B-154C
in order to digitally pan or digitally zoom the fovea 650. In this
manner, intuitive camera control can be provided to the assistant,
as an alternative to mechanically moving the camera with the camera
clutch.
[0209] As another aspect of the invention, the monitor 154 may also
be moved along and rotated about the axes to possibly control the
movements of a robotic surgical tool 101, such as during initial
set up or during surgery to control an extra tool, such as a
suction tool for example. Another extra robotic surgical tool that
may be controlled by an assistant is an ultrasound tool. The images
generated by the ultrasound tool can be displayed on the monitor
154 as well the display devices 402L,402R in the stereo viewer 312.
As the ultrasound tool is moved over surfaces in the surgical site,
the ultrasound images that are displayed change.
System and Operational Methods
[0210] Referring now to FIG. 16, a functional block diagram of a
digital video zoom subsystem 1600 is illustrated. The subsystem
1600 is an aspect of the robotic surgical system that may provide
the digital zoom portion of video information and the automatic
panning of video information in a surgical site.
[0211] The subsystem 1600 may include an image acquisition device
(endoscopic camera) 1602, an image buffer 1604, a first digital
mapper and image filter 1606A, a first user interface 1608A, a
first display buffer 1610A, and a first display device 1612A
coupled together as shown. The first display device 1612A may be
one of the display device 154 or the stereo display devices
402L,402R, for example. The subsystem 1600 may further include a
second digital mapper and image filter 1606B, a second user
interface 1608B, a second display buffer 1610B, and a second
display device 1612B coupled together as shown and independent of
the first devices.
[0212] The image acquisition device 1602 may capture images of a
surgical site in a high definition image format. The image buffer
1604 buffers one or more frames of a matrix of pixel data. The
first digital mapper and image filter 1606 may map and filter the
pixels in the captured images to properly display pixels on the
first display device 1612A as desired. The first display buffer
1610 is coupled between the image filter 1606 and the first display
device 1612A to store one or more frames of pixel information for
display on the display device.
[0213] The first user interface 1608A may include a region of
interest (fovea) selector 1620, a user preference selector 1622,
and an enhanced display mode selector 1624 to select an enhanced
display mode 1634. The region of interest (fovea) selector 1620 may
function similar to the method and apparatus for automatic digital
panning of the fovea 650 as described previously. A user may select
how the source rectangle should automatically adjust its position
with respect to an estimated tool centroid 1630, depth 1631, user
focal-point, or mean working envelope, for example. The user
preference selector 1622 allows a user to manually select the
source data from a source rectangle 1632, such as a full-spatial
high definition image, and manually select the destination
rectangle 1633 for where the image may be preferably displayed on
the first display device 1612A. Without the enhanced display mode
being selected, the user may manually select the source rectangle
1632 and the destination rectangle 1633. If the system is selected
to be in an enhanced display mode, the source rectangle 1632 and/or
the destination rectangle 1633 may be automatically selected based
on one or more of the estimated tool centroid 1630, the depth 1631,
the user focal-point, or the mean working envelope. In some cases,
a user may select a fixed destination rectangle while the source
rectangle 1632 is automatically selected.
[0214] As the image acquisition device 1602 captures digital pixel
data of images of a surgical site that are stored in the image
buffer 1604, the pixel data can be independently selected for
viewing by multiple display devices.
[0215] The second digital mapper and image filter 1606B, the second
user interface 1608B, and the second display buffer 1610B are for
independent selection and display of images on the second display
device 1612B. For example, the first display 1612A may be the
stereo display devices 402L,402R in the console 150 while the
second display 1612B may be the assistant's display device 154
illustrated in FIG. 1A. A first user may independently select user
preferences for the first display with the first user interface
1608A, while a second user may independently select user
preferences for the second display with the second user interface
1608B. The second user interface 1608B is substantially similar to
the first user interface 1608A and its description is incorporated
herein by reference for brevity. Alternatively, the second digital
mapper and image filter 1606B, the second user interface 1608B, and
the second display buffer 1610B may be synchronized to the first
devices such that the display of images on the second display
device 1612B are similar to the display of images on the first
display device 1612A.
CONCLUSION
[0216] The embodiments of the invention have now been
described.
[0217] A number of elements of the system may be implemented in
software and executed by a computer and its processor, such as
computer 151 and its processor 302. When implemented in software,
the elements of the embodiments of the invention are essentially
the code segments to perform the necessary tasks. The program or
code segments can be stored in a processor readable medium or
transmitted by a computer data signal embodied in a carrier wave
over a transmission medium or communication link. The processor
readable medium may include any medium that can store or transfer
information. Examples of the processor readable medium include an
electronic circuit, a semiconductor memory device, a read only
memory (ROM), a flash memory, an erasable programmable read only
memory (EPROM), a floppy diskette, a CD-ROM, an optical disk, a
hard disk, a fiber optic medium, a radio frequency (RF) link, etc.
The computer data signal may include any signal that can propagate
over a transmission medium such as electronic network channels,
optical fibers, air, electromagnetic, RF links, etc. The code
segments may be downloaded via computer networks such as the
Internet, Intranet, etc.
[0218] While certain exemplary embodiments have been described and
shown in the accompanying drawings, it is to be understood that
such embodiments are merely illustrative of and not restrictive on
the broad invention, and that the embodiments of the invention not
be limited to the specific constructions and arrangements shown and
described, since various other modifications may become apparent
after reading the disclosure. For example, while the inner/outer
pair of source windows 661 and inner/outer pair of target windows
671 have been shown and described as being rectangular in shape,
they may be circular in shape in alternate embodiments of the
invention. Additionally, some embodiments of the invention have
been described with reference to a video system in a robotic
surgical system. However, these embodiments may be equally
applicable to other video systems. Thus, the embodiments of the
invention should be construed according to the claims that follow
below.
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