U.S. patent application number 14/613221 was filed with the patent office on 2015-08-13 for systems and methods for using x-ray field emission to determine instrument position and orientation.
The applicant listed for this patent is Intuitive Surgical Operations, Inc.. Invention is credited to Prashant Chopra.
Application Number | 20150223765 14/613221 |
Document ID | / |
Family ID | 53773897 |
Filed Date | 2015-08-13 |
United States Patent
Application |
20150223765 |
Kind Code |
A1 |
Chopra; Prashant |
August 13, 2015 |
SYSTEMS AND METHODS FOR USING X-RAY FIELD EMISSION TO DETERMINE
INSTRUMENT POSITION AND ORIENTATION
Abstract
A device is provided that comprises: a flexible body; a position
sensor located at the flexible body; and a field emission x-ray
device located at the flexible body.
Inventors: |
Chopra; Prashant; (Foster
City, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intuitive Surgical Operations, Inc. |
Sunnyvale |
CA |
US |
|
|
Family ID: |
53773897 |
Appl. No.: |
14/613221 |
Filed: |
February 3, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61937360 |
Feb 7, 2014 |
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Current U.S.
Class: |
600/424 |
Current CPC
Class: |
A61B 6/025 20130101;
A61B 5/065 20130101; A61B 1/0607 20130101; A61B 6/12 20130101; A61B
6/547 20130101; A61B 1/005 20130101; A61B 6/4057 20130101 |
International
Class: |
A61B 6/12 20060101
A61B006/12; A61B 6/00 20060101 A61B006/00; A61B 6/02 20060101
A61B006/02; A61B 5/06 20060101 A61B005/06 |
Claims
1. A device comprising: a flexible body; a position sensor located
at the flexible body; and a field emission x-ray device located at
the flexible body.
2. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, and further
including: multiple field emission x-ray devices located at the
distal end portion.
3. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, and further
including: multiple field emission x-ray devices located at the
distal end portion, wherein the distal end portion includes a
circumference, and wherein the multiple field emission x-ray
devices are disposed angularly displaced about the circumference of
the distal end portion.
4. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, and further
including: multiple field emission x-ray devices located at the
distal end portion, wherein the multiple field emission x-ray
devices are configured to emit x-rays on adjacent paths.
5. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, and further
including: multiple field emission x-ray devices located at the
distal end portion, wherein the multiple field emission x-ray
devices are configured to emit x-rays on parallel paths.
6. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, and further
including: multiple field emission x-ray devices located at the
distal end portion; and an effector located at the distal end
portion, wherein the multiple field emission x-ray devices are
configured to emit x-rays on paths incident upon a working volume
located within a human body.
7. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, and further
including: multiple field emission x-ray devices located at the
distal end portion; and an effector located at the distal end
portion, wherein the multiple field emission x-ray devices are
configured to emit x-rays on paths that are incident upon a volume
that is displaced from a working volume located within a human
body.
8. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, wherein the distal
end portion is sized and shaped to be inserted within a human body,
and wherein the field emission x-ray device is located at the
distal end portion; and further including: a communications
interface located at the proximal end portion.
9. The device of claim 1, wherein the field emission x-ray device
includes a carbon nanotube.
10. The device of claim 1, wherein the position sensor includes an
electromagnetic (EM) sensor.
11. The device of claim 1, wherein the position sensor includes a
shape sensor.
12. The device of claim 1, wherein the position sensor includes an
image capture element.
13. The device of claim 1, wherein the flexible body includes a
distal end portion and a proximal end portion, and wherein the
field emission x-ray device is located at the distal end portion,
and further including: a communications interface located at the
proximal end portion; and steering controls that are housed within
the flexible body and that extend between the communications
interface and the distal end portion.
14. The device of claim 1, further including steering controls that
include cables.
15. The device of claim 1, wherein the flexible body includes a
plurality of segments.
16. The device of claim 1, wherein the flexible body defines at
least one internal lumen.
17. A system comprising: a flexible body sized and shaped to be
inserted within a human body; a detector configured to capture one
or more x-ray images produced using a field emission x-ray device;
and one or more processors configured to determine similarity
between the captured one or more x-ray images and a reference
image.
18. The system of claim 17, further comprising: a position sensor
located at the flexible body; and wherein the one or more
processors are configured to: use the position sensor to sense a
pose of the flexible body; determine an estimated detected pose of
the flexible body as a function of a determined similarity between
the captured one or more x-ray images and a reference image;
determine an estimated offset between the sensed pose and the
estimated detected pose; and change a pose of a distal end portion
of the flexible body as a function of the determined estimated
offset.
19. The system of claim 18, wherein sensing a pose of the distal
end portion of the flexible body includes shape sensing.
20. The system of claim 18, wherein sensing a pose of the distal
end portion of the flexible body includes electromagnetic
sensing.
21. The system of claim 17, wherein the one or more processors are
configured to convert the one or more captured x-ray images to at
least one tomosynthesis image and wherein determining similarity
includes searching for similarity between the at least one
tomosynthesis image and a reference image.
22. A method comprising: locating a field emission x-ray device at
a distal end portion of a flexible body; inserting the flexible
body and the field emission x-ray device into an anatomical cavity
within a patient's anatomy; emitting x-ray radiation from the x-ray
device; and detecting the x-ray radiation emitted at a location
outside the anatomical cavity.
23. The method of claim 22, wherein inserting includes inserting
into a body organ.
24. The method of claim 22, wherein the anatomical cavity includes
a natural lung passage.
25. The method of claim 22, wherein the anatomical cavity includes
a natural heart passage.
26. The method of claim 22, wherein the anatomical cavity includes
a natural digestive system passage.
27. The method of claim 22, wherein detecting the emitted x-ray
radiation includes capturing an x-ray image that includes an x-ray
attenuation pattern indicative of anatomical structures traversed
by the x-ray radiation, and further including: determining a
similarity between the captured x-ray image and a reference image
obtained from a three-dimensional (3-D) reference image of a
portion of the patient's anatomy that includes the anatomical
cavity.
28. The method of claim 27, further including: sensing a pose of a
distal end portion of the flexible body; determining an estimated
detected pose of the distal end portion as a function of the
determined similarity of the reference image; determining an
estimated offset between the sensed pose and the estimated detected
pose; and changing the pose of the distal end portion as a function
of the determined offset.
29. The method of claim 28, wherein sensing the pose of the distal
end portion of the flexible body includes shape sensing.
30. The method of claim 28, wherein sensing the pose of the distal
end portion of the flexible body includes electromagnetic
sensing.
31. The method of claim 28, wherein sensing includes sensing a pose
of the distal end portion of the flexible body.
32. The method of claim 27, wherein determining the similarity
includes comparing captured x-ray image information with
information for multiple different reference images obtained from
the three-dimensional (3-D) reference image.
33. The method of claim 27, wherein determining the similarity
includes comparing a visual display representing captured x-ray
images with visual displays for multiple different reference images
obtained from the three-dimensional (3-D) reference image.
34. The method of claim 22, further comprising: wherein detecting
the emitted x-ray radiation includes capturing multiple x-ray
images that include x-ray attenuation patterns indicative of
anatomical structures traversed by the x-ray radiation; converting
the multiple x-ray images to at least one tomosynthesis image;
determining a similarity between the at least one tomosynthesis
image and a reference image obtained from a three-dimensional (3-D)
reference image of a portion of a patient's body that includes the
anatomical cavity.
35. The method of claim 34 further including: sensing a pose of the
distal end portion of the flexible body; determining an estimated
detected pose of the distal end portion as a function of the
determined similarity of the reference image; determining an
estimated offset between the sensed pose and the detected pose; and
changing the pose of the distal end portion as a function of the
determined offset.
36. The method of claim 35, wherein sensing the pose of the distal
end portion of the flexible body includes shape sensing.
37. The method of claim 35, wherein sensing the pose of the distal
end portion of the flexible body includes electromagnetic
sensing.
38. The method of claim 35, wherein sensing includes sensing a pose
of the distal end portion of the flexible body.
39. The method of claim 35, further including comparing
tomosynthesis image information with information for multiple
different reference images obtained from the three-dimensional
(3-D) reference image to determine a match.
40. The method of claim 34, further including comparing a visual
display representing tomosynthesis image information with visual
displays for multiple different reference images obtained from the
three-dimensional (3-D) reference image to determine a match.
41. A system comprising: a flexible body; a field emission x-ray
device located at the flexible body; a detector configured to
capture one or more x-ray images produced by the field emission
x-ray device; and one or more processors configured to: sense a
pose of a distal end of the flexible body; select a predicted
reference image, as a function of the sensed pose, from a
three-dimensional (3-D) reference image; and search for similarity
between the captured one or more x-ray images and a reference image
obtained from a prescribed region of the three-dimensional (3-D)
reference image about the predicted reference image.
42. The system of claim 41, wherein the one or more processors are
configured to convert the one or more captured x-ray images to at
least one tomosynthesis image, and wherein searching for similarity
includes searching for similarity between the at least one
tomosynthesis image and a reference image.
43. A system comprising: a flexible body; a field emission x-ray
device located at the flexible body; a position sensor located at
the flexible body; a detector configured to detect one or more
x-ray images produced using the field emission x-ray device; and
one or more processors configured to: use the position sensor to
sense a pose of the flexible body; select a predicted reference
image, as a function of the sensed pose, from a three-dimensional
(3-D) reference image; search for a match between the detected one
or more x-ray images and a reference image obtained from a
prescribed region of the three-dimensional (3-D) reference image
about the predicted reference image; determine an estimated
detected pose of the flexible body as a function of a determined
match between the one or more detected x-ray images and a reference
image; determine an estimated offset between the sensed pose and
the detected pose; and change the pose of the flexible body as a
function of the determined offset.
44. A method comprising: providing a field emission x-ray device at
a distal end portion of a flexible body; inserting the flexible
body and the field emission x-ray device into an anatomical cavity
within a patient's body; emitting x-ray radiation from the x-ray
device; capturing an x-ray image that includes an x-ray attenuation
pattern indicative of anatomical structures traversed by the x-ray
radiation; sensing a pose of the distal end portion of the flexible
body; selecting a predicted reference image, as a function of the
sensed pose, from a three-dimensional (3-D) reference image of a
portion of a patient's anatomy that includes the anatomical cavity;
and searching for similarity between the captured x-ray image and a
reference image obtained from a prescribed region of the
three-dimensional (3-D) reference image about the predicted
reference image.
45. The method of claim 44, wherein capturing the x-ray image
includes capturing multiple x-ray images; and wherein searching for
similarity includes converting the multiple captured x-ray images
to at least one tomosynthesis image and searching for similarity
between the at least one tomosynthesis image and a reference image
obtained from a prescribed region of the three-dimensional (3-D)
reference image about the predicted reference image.
46. A method comprising: inserting a flexible body that includes a
position sensor and a field emission x-ray device into a human body
cavity; detecting one or more x-ray images emitted from the field
emission x-ray device; using the position sensor to sense a pose of
the flexible body; selecting a predicted reference image, as a
function of the sensed pose, from a three-dimensional (3-D)
reference image; searching for a match between the one or more
detected x-ray images and a reference image obtained from a
prescribed region of the three-dimensional (3-D) reference image
about the predicted reference image; determining an estimated
detected pose of the flexible body as a function of a determined
match between the one or more detected x-ray images and a reference
image; determining an estimated offset between the sensed pose and
the estimated detected pose; and changing the pose of the flexible
body as a function of the determined estimated offset.
Description
CLAIM OF PRIORITY
[0001] This application claims the benefit of priority under 35
U.S.C. .sctn.119(e) to U.S. Provisional Patent Application Ser. No.
61/937,360, filed on Feb. 7, 2014, which is incorporated by
reference herein in its entirety.
FIELD
[0002] The present disclosure is directed to systems and methods
for tracking a medical device within a patient anatomy during a
medical procedure, and more particularly to systems and methods for
efficiently tracking a medical device within a patient anatomy
using instrument-mounted field emission x-ray devices.
BACKGROUND
[0003] Minimally invasive medical techniques are intended to reduce
the amount of tissue that is damaged during diagnostic or surgical
procedures, thereby reducing patient recovery time, discomfort, and
deleterious side effects. Such minimally invasive techniques may be
performed through natural orifices in a patient anatomy or through
one or more surgical incisions. Through these natural orifices or
incisions clinicians may insert surgical instruments to reach a
target tissue location. To reach the target tissue location, the
minimally invasive surgical instruments may navigate natural or
surgically created connected passageways in anatomical systems such
as the lungs, the colon, the intestines, the kidneys, the heart,
the circulatory system, or the like. Navigational assist systems
help the clinician route the surgical instruments and avoid damage
to the anatomy. These systems can incorporate the use of position
and shape sensors to more accurately describe the shape, pose, and
position of the surgical instrument in real space or with respect
to pre-procedural or concurrent images. In a dynamic anatomical
system and/or in an anatomical region dense with many anatomical
passageways, determinations of the position, orientation and pose
of an instrument can be imprecise, especially when considered
relative to a target tissue volume that is tiny or to passageways
to be navigated that are narrow and complex.
SUMMARY
[0004] In one aspect, a device is provided that includes a flexible
body. A position sensor is located at the flexible body. A field
emission x-ray device is located at the flexible body.
[0005] In another aspect, a method is provided that includes
providing a field emission x-ray device to a distal end portion of
a flexible body. The flexible body, the position sensor and the
field emission x-ray device are inserted into an anatomical cavity
within a patient's anatomy. X-ray radiation is emitted from the
x-ray device and is detected at a location outside the anatomical
cavity.
[0006] In another aspect, a system is provided that includes a
flexible body sized and shaped to be inserted within a human body.
A detector is configured to capture one or more x-ray images
produced using a field emission x-ray device. One or more
processors are configured to determine similarity between the
captured one or more x-ray images and a reference x-ray image.
[0007] In yet another aspect, a method is provided in which a field
emission x-ray device is located at a distal end portion of a
flexible body. The flexible body and the field emission x-ray
device are inserted into an anatomical cavity within a patient's
anatomy. X-rays are emitted from the x-ray device. An x-ray image
is captured that includes an x-ray attenuation pattern indicative
of anatomical structures traversed by the x-ray radiation. A pose
is sensed of the distal end portion of the flexible body. A
predicted reference x-ray image is selected, as a function of the
sensed pose, from a three-dimensional (3-D) reference x-ray image
of a portion of a patient's anatomy that includes the anatomical
cavity. A search is made for a match between the captured x-ray
image and a reference x-ray image obtained from a prescribed region
of the three-dimensional (3-D) reference x-ray image about the
predicted reference x-ray image.
[0008] In still another aspect, multiple x-ray images are captured
and are converted to one or more tomosynthesis images. The search
involves a search for a match between the one or more tomosynthesis
images and a reference x-ray image obtained from the
three-dimensional (3-D) reference x-ray image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Aspects of the present disclosure are best understood from
the following detailed description when read with the accompanying
figures. It is emphasized that, in accordance with the standard
practice in the industry, various features are not drawn to scale.
In fact, the dimensions of the various features may be arbitrarily
increased or reduced for clarity of discussion. In addition, the
present disclosure may repeat reference numerals and/or letters in
the various examples. This repetition is for the purpose of
simplicity and clarity and does not in itself dictate a
relationship between the various embodiments and/or configurations
discussed.
[0010] FIG. 1 is an illustrative drawing of a robotic surgical
system in accordance with some embodiments.
[0011] FIG. 2A is an illustrative drawing representing a tracked
instrument system which includes the surgical instrument system of
FIG. 1 and its interfacing systems in accordance with some
embodiments.
[0012] FIG. 2B provides an illustrative perspective view of the end
portion, which includes multiple field emission x-ray devices used
to generate information in the form of 2-D projection images that
are indicative of the location of a working volume in accordance
with some embodiments.
[0013] FIG. 3 is a generalized longitudinal end view of the distal
end of the end portion showing disposition of multiple x-ray
emission devices disposed about a circumference of the end portion
in accordance with some embodiments.
[0014] FIGS. 4A-4D are illustrative cross-sectional side views of
the distal end portion shown in FIG. 3 in accordance with some
embodiments.
[0015] FIG. 5 is an illustrative drawing representing spatial
disposition of the eight x-ray projection images of FIGS. 4A-4D in
accordance with some embodiments.
[0016] FIG. 6 is an illustrative drawing showing multiple
tomosynthesis images generated by the visualization system based
upon the x-ray projection images in accordance with some
embodiments.
[0017] FIG. 7 is an illustrative drawing representing a 2-D
reference image slice selected from a 3-D reference computed
tomography image for matching with one or more tomosynthesis image
slices in accordance with some embodiments.
[0018] FIG. 8 is an illustrative drawing representing a detected
tomosynthesis image and a 2-D reference image for comparison in
accordance with some embodiments.
[0019] FIG. 9 is an illustrative drawing of an example screen
display showing multiple 2-D reference slices alongside a selected
tomosynthesis slice in accordance with some embodiments.
[0020] FIG. 10 is an illustrative drawing of an alternative
embodiment of the end portion in which the emission sources are
arranged to emit x-ray radiation in a direction generally parallel
to the central axis of the end portion in accordance with some
embodiments.
[0021] FIG. 11 is an illustrative drawing representing an
alternative embodiment showing an end portion of a flexible medical
instrument having x-ray emission devices configured to emit x-ray
beams that intersect body tissue at a location that is displaced
from a working volume.
[0022] FIG. 12 is an illustrative flow diagram representing a
process search for similarity between detected 2-D x-ray images and
one or more 2-D reference x-ray images in accordance with some
embodiments.
[0023] FIGS. 13A-13B are illustrative drawings showing two
different example offsets between predicted and actual poses of the
end portion of the flexible medical instrument in accordance with
some embodiments.
[0024] FIG. 14A is an illustrative drawing representing a composite
image including an image of a human lung, from a viewpoint external
to the lung, registered with an instrument image of a flexible
instrument in accordance with some embodiments.
[0025] FIG. 14B shows the composite image of FIG. 14A and also
shows a first example discrepancy between first detected and
predicted flexible medical instrument poses in accordance with some
embodiments.
[0026] FIG. 14C shows the composite image of FIG. 14A and also
shows a second example discrepancy between second detected and
predicted flexible medical instrument poses in accordance with some
embodiments.
[0027] FIG. 15 is an illustrative drawing representing an internal
image of a portion of the human lung of FIGS. 14A-14C depicting a
region of the lung from the viewpoint along a Z-axis of the end
portion the instrument flexible medical instrument poses in
accordance with some embodiments.
[0028] FIG. 16 shows an illustrative diagrammatic representation of
a more particularized computer system to implement the generalized
computer system of FIG. 16.
DESCRIPTION OF EMBODIMENTS
[0029] The following description is presented to enable any person
skilled in the art to create and use a system to use field emission
x-rays to ascertain and to adjust position and orientation of a
flexible robotic medical instrument within an anatomical volume.
Various modifications to the embodiments will be readily apparent
to those skilled in the art, and the generic principles defined
herein may be applied to other embodiments and applications without
departing from the spirit and scope of the inventive subject
matter. Moreover, in the following description, numerous details
are set forth for the purpose of explanation. However, one of
ordinary skill in the art will realize that the inventive subject
matter might be practiced without the use of these specific
details. In other instances, well-known machine components,
processes and data structures are shown in block diagram form in
order not to obscure the disclosure with unnecessary detail.
Identical reference numerals may be used to represent different
views of the same item in different drawings. Flow diagrams in
drawings referenced below are used to represent processes. A
computer system may be configured to perform some of these
processes. Modules within flow diagrams representing computer
implemented processes represent the configuration of a computer
system according to computer program code to perform the acts
described with reference to these modules. Thus, the inventive
subject matter is not intended to be limited to the embodiments
shown, but is to be accorded the widest scope consistent with the
principles and features disclosed herein.
DEFINITIONS
[0030] The embodiments below will describe various instruments and
portions of instruments in terms of their state in
three-dimensional space.
[0031] As used herein, the term "position" refers to the location
of an object or a portion of an object in a three-dimensional space
(e.g., three degrees of translational freedom along Cartesian X, Y,
Z coordinates).
[0032] As used herein, the term "orientation" refers to the
rotational placement of an object or a portion of an object (three
degrees of rotational freedom--e.g., roll, pitch, and yaw).
[0033] As used herein, the term "pose" refers to the position of an
object or a portion of an object in at least one degree of
translational freedom and to the orientation of that object or
portion of the object in at least one degree of rotational freedom
(up to six total degrees of freedom).
[0034] As used herein, the term "shape" refers to a set of poses,
positions, or orientations measured along an object.
[0035] As used herein, the term "working volume" refers to a volume
that is adjacent to an end portion of the medical instrument and
that is accessible from the end portion for treatment or
diagnosis.
Introduction
[0036] In some embodiments, in operation, a medical instrument
extends within an anatomical volume within a patient's body.
Multiple field emission devices are mounted to an end portion of
the instrument and are aligned to emit x-ray radiation that is
incident upon a working volume. The working volume changes with
changes of position or orientation of the end portion within the
anatomical volume. An x-ray detector is disposed in a spaced
relation to the end portion and in alignment with radiation beams
emitted from the field emission devices so as to capture one or
more x-ray images from a viewpoint of the end portion. The
radiation beams are attenuated as they pass through body tissue
disposed between the emission devices and the detector. The denser
the tissue material, the greater will be the attenuation of the
beams. The captured x-ray images, which are indicative of a
detected actual location of the end portion of the instrument, show
beam attenuation patterns that represent structures disposed
between the emission devices and the detector from the viewpoint of
the end portion. A predicted location of the working volume is
determined based at least in part upon sensing of a pose of the
instrument. Reference image information corresponding to the
predicted pose of the end portion of the instrument, and therefore
of the x-ray devices mounted thereon, within the patient's body can
be obtained from a 3-D planning image of the patient's body.
Captured x-ray image information corresponding to the detected
actual location of the end portion is compared with reference x-ray
image information corresponding to the predicted pose of the end
portion of the instrument. In response to a difference between the
actual and predicted pose of the end portion of the instrument, a
pose of at least a portion of the instrument is changed to change
the working volume.
Robotic Surgical System
[0037] FIG. 1 is an illustrative drawing of a robotic surgical
system generally indicated by the reference numeral 100, in
accordance with some embodiments. The robotic system 100 generally
includes a surgical manipulator assembly 102 for controlling
operation of a surgical instrument 104 in performing various
procedures on a patient P. The assembly 102 is mounted to or near
an operating table O. A master assembly 106 allows a surgeon S to
view the surgical site and to control the manipulator assembly
102.
[0038] In alternative embodiments, the robotic system may include
more than one manipulator assembly. The exact number of manipulator
assemblies will depend on the surgical procedure and the space
constraints within the operating room among other factors.
[0039] The master assembly 106 may be located at a surgeon's
console C which is usually located in the same room as operating
table O. However, it should be understood that the surgeon S can be
located in a different room or a completely different building from
the patient P. Master assembly 106 generally includes an optional
support 108 and one or more control device(s) 112 for controlling
the manipulator assembly 102. The control device(s) 112 may include
any number of a variety of input devices, such as joysticks,
trackballs, gloves, trigger-guns, hand-operated controllers, voice
recognition devices or the like. In some embodiments, the control
device(s) 112 will be provided with the same degrees of freedom as
the associated surgical instruments 104 to provide the surgeon S
with telepresence, or the perception that the control device(s) 112
are integral with the instrument 104 so that the surgeon S has a
strong sense of directly controlling instrument 104. In some
embodiments, the control device(s) 112 is a manual input device
which moves with six degrees of freedom, and which may also include
an actuatable handle for actuating instruments (for example, for
closing grasping jaws, applying an electrical potential to an
electrode, delivering a medicinal treatment, or the like).
[0040] A visualization system 110 provides a concurrent two or
three dimensional image of a surgical site to surgeon console C.
The visualization system 110 may include a viewing scope assembly
(described in greater detail below) such that a concurrent or
real-time visual image of a surgical site is provided to surgeon
console C. In some embodiments, visual images also may be captured
by an endoscope positioned within the surgical site. In some
embodiments, the visualization system 110 includes x-ray field
emission components that may be integrally or removably coupled to
the surgical instrument 104 such that a concurrent x-ray image of a
surgical site is provided to surgeon console C. In alternative
embodiments, a separate endoscope, attached to a separate
manipulator assembly, may be used with the surgical instrument 104
to image the surgical site. The visualization system 110 may be
implemented as hardware, firmware, software or a combination
thereof which interact with or are otherwise executed by one or
more computer processors, which may include the processors of a
control system 116 (described below).
[0041] A display system 111 may display a visual image of the
surgical site and surgical instruments 104 captured by the
visualization system 110. The display system 111 and the master
control devices 112 may be oriented such that the relative
positions of the visual imaging device in the scope assembly and
the surgical instruments 104 are similar to the relative positions
of the surgeon's eyes and hands so the operator can manipulate the
surgical instrument 104 and the hand control as if viewing a
working volume adjacent to the instrument 104 in substantially true
presence. By "true presence" it is meant that the presentation of
an image is a true perspective image simulating the viewpoint of an
operator that is physically manipulating the surgical instruments
104.
[0042] Alternatively or additionally, display system 111 may
present images of the surgical site recorded and/or modeled
preoperatively using imaging technology such as computerized
tomography (CT), magnetic resonance imaging (MRI), fluoroscopy,
thermography, ultrasound, optical coherence tomography (OCT),
thermal imaging, impedance imaging, laser imaging, or nanotube
X-ray imaging. The presented preoperative images, also referred to
as "planning images", may include two-dimensional,
three-dimensional, or four-dimensional images. In some embodiments,
the display system 111 may display a virtual navigational image in
which the current location of the surgical instrument 104 is
registered (i.e., dynamically referenced) with preoperative or
concurrent images to present the surgeon S with a virtual image of
the internal surgical site at the location of an end portion of the
surgical instrument 104. An image of the end portion of the
surgical instrument 104 or other graphical or alphanumeric
indicators may be superimposed on the virtual image to assist the
surgeon S in controlling the surgical instrument 104.
Alternatively, the surgical instrument 104 may not be visible in
the virtual image.
[0043] In other embodiments, the display system 111 may display a
virtual navigational image in which the current location of the
surgical instrument 104 is registered with preoperative or
concurrent images to present the surgeon S with a virtual image of
the surgical instrument 104 within the surgical site from an
external viewpoint. An image of a portion of the surgical
instrument 104 or other graphical or alphanumeric indicators may be
superimposed on the virtual image to assist the surgeon S in
controlling the surgical instrument 104.
[0044] As shown in FIG. 1, a control system 116 includes at least
one processor (not shown) and typically a plurality of processors
for effecting control between the surgical manipulator assembly
102, the master assembly 106, and the display system 110. The
control system 116 also includes software programming instructions
to implement some or all of the methods described herein. While
control system 116 is shown as a single block in the simplified
schematic of FIG. 1, the control system 116 may comprise a number
of data processing circuits (e.g., on the surgical manipulator
assembly 102 and/or on the master assembly 106), with at least a
portion of the processing optionally being performed adjacent an
input device, a portion being performed adjacent a manipulator, and
the like. Any of a wide variety of centralized or distributed data
processing architectures may be employed. Similarly, the
programming code may be implemented as a number of separate
programs or subroutines, or may be integrated into a number of
other aspects of the robotic systems described herein. In one
embodiment, control system 116 may support wireless communication
protocols such as Bluetooth, IrDA, HomeRF, IEEE 802.11, DECT, and
Wireless Telemetry.
[0045] In some embodiments, control system 116 may include servo
controllers to provide force and torque feedback from the surgical
instrument 104 to the hand-operated control device 112. Any
suitable conventional or specialized servo controller may be used.
A servo controller may be separate from, or integral with,
manipulator assembly 102. In some embodiments, the servo controller
and manipulator assembly 102 are provided as part of a robotic arm
cart positioned adjacent to the patient's body. The servo
controllers transmit signals instructing the manipulator assembly
102 to move the instrument 104, which extends into an internal
surgical site within the patient body via openings in the body.
Each manipulator assembly 102 supports a surgical instrument 104
and may comprise a series of manually articulatable linkages,
generally referred to as set-up joints, and a robotic manipulator.
The manipulator assembly 102 may be driven by a series of actuators
(e.g., motors). These motors actively move the robotic manipulators
in response to commands from the control system 116. The motors are
further coupled to the surgical instrument 104 so as to advance the
surgical instrument 104 into a naturally or surgically created
anatomical orifice and to move the surgical instrument 104 in
multiple degrees of freedom that may include three degrees of
linear motion (e.g., X, Y, Z linear motion) and three degrees of
rotational motion (e.g., roll, pitch, yaw). Additionally, the
motors can be used to actuate an effector of the surgical
instrument 104 such as an articulatable effector for grasping
tissues in the jaws of a biopsy device or an effector for obtaining
a tissue sample or for dispensing medicine, or another effector for
providing other treatment as described more fully below, for
example.
Tracked Instrument System
[0046] FIG. 2A is an illustrative drawing representing a tracked
instrument system 118 which includes the robotic system 100 of FIG.
1 and its interfacing systems in accordance with some embodiments.
The tracked instrument system 118 includes a flexible instrument
120 coupled by an electro-optical communications interface 122 to
the manipulator assembly 102 and visualization system 110. The
interface 122 includes circuitry and/or fiber optics configured to
communicate control signals and information-containing signals,
such as electrical signals indicating the disposition of an end
effector 132 and optical signals indicating instrument shape,
between the manipulator assembly 102 and the flexible instrument
120. The interface 122 also includes circuitry and/or fiber optics
configured to communicate control signals and
information-containing signals, such as signals indicating a
captured image, between the visualization system 110 and the
flexible instrument 120. The flexible instrument 120 includes an
elongated flexible body 124, an end portion 126 at its distal end
128, and the interface 122 at its proximal end 130. The body 124
houses cables, linkages, or other steering controls (not shown)
that extend between the interface 122 and the end portion 126 to
controllably bend or turn the end portion 126 as shown for example
by the dotted line versions of the end portion 126, and in some
embodiments control an optional end effector 132.
[0047] The flexible instrument 120 may be steerable, including the
steering controls previously described, or may be non-steerable
with no integrated mechanism for operator control of the flexible
instrument 120 bending. The end effector 132 may be a working
distal part that is manipulable for a medical function, e.g., for
effecting a predetermined treatment of a target tissue. For
instance, some end effectors have a single working member such as a
scalpel, a blade, or an electrode. Other end effectors, such as end
effector 132 shown in the embodiment of FIG. 2A, have a pair or
plurality of working members such as forceps, graspers, scissors,
or clip appliers, for example. Examples of electrically activated
end effectors include electrosurgical electrodes, transducers,
sensors, and the like. End effectors may also include conduits to
convey fluids, gases or solids to perform, for example, suction,
insufflation, irrigation, certain treatments requiring fluid
delivery, accessory introduction, biopsy extraction, and the like.
In other embodiments, the flexible body 124 can define one or more
lumens through which surgical instruments can be deployed and used
at a target surgical location.
[0048] The flexible instrument 120 can also include an image
capture element 134, which may include a stereoscopic or monoscopic
camera disposed at the distal end 128 for capturing images that are
transmitted to and processed by the visualization system 110 for
display by the display system 111. Alternatively, the image capture
element 134 may include a coherent fiber-optic bundle that couples
to an imaging and processing system on the proximal end 130 of the
flexible instrument 120, such as a fiberscope. The image capture
element 134 may be single or multi-spectral for capturing image
data in the visible or infrared/ultraviolet spectrum.
[0049] FIG. 2B provides an illustrative perspective view of the end
portion 126, which includes multiple field emission x-ray devices
181-188 used to generate information in the form of 2-D projection
images that are indicative of the location of a working volume in
accordance with some embodiments. The end portion 126 has a center
axis 190, which extends along a Z-direction, and the field emission
x-ray devices 181-188 are secured to the end portion 126, either
integrally or removably, about the center axis 190. The x-ray
emissions emitted by the x-ray devices 181-188 are attenuated as
they pass through the patient body and are captured as 2-D x-ray
projection images by one or more x-ray detectors 260 (of FIGS.
4A-4D) mounted on structure 261. The 2-D projection images provide
information concerning the structure and density of body tissue
disposed between the end portion 126 and an x-ray detector (not
shown), which can be used to determine the location of the working
volume. More particularly, information from the 2-D projection
images is processed by the visualization system 110 for use in
generating a display by the display system 111 to provide an
indication of the location, orientation and/or pose of the end
portion 126, and therefore, of the x-ray devices 181-188 mounted
thereon. Information concerning the location orientation and/or
pose of the end portion 126 determined using the 2-D projection
images can be compared with planning images to aid a surgeon in
manipulating the surgical instrument 104 so as to guide the end
portion 126 to bring the working volume into alignment with an
intended target volume.
[0050] In some embodiments, the field emission x-ray devices
181-188 include carbon nanotubes (CNTs) that are configured to act
as electron emission sources for the production of x-ray radiation.
Field emission involves extraction of electrons from a conducting
solid by an electric field. In general, relatively high electric
fields are needed for the electrons to tunnel through a surface
potential barrier and to achieve field emission. However, when the
solid is shaped as a sharp tip, the electric field lines are
concentrated around the tip and the local electric field is
enhanced. This geometrical enhancement of the electric field is
used in field emitters to allow extraction of electrons from sharp
tips at relatively low macroscopic electric fields. CNTs are among
the sharpest and strongest materials known, and as a result, they
are effective materials for use as field emission x-ray devices,
also referred to as cathodes. It will be appreciated that since
field emission of electrons is produced by a high electric field,
no heating is necessary. Field emission sources are thus often
referred to as cold cathode sources. Beneficially, the electron
beams emitted by a field emission source may have low divergence
and thus provide ease of focusing onto a focal spot. Moreover, the
virtually instantaneous response of a typical field emission source
to an electric field results in rapid switching capabilities that
sometimes may even be on the order of nanoseconds, for example.
Furthermore, because field emission sources can be made exceedingly
small, field emission x-ray sources are highly amenable to
formation into arrays that comprise multiple sources. Further
discussions of carbon nanotube based field-emission x-ray sources
are provided by Chang et al., "Dynamic radiography using a
carbon-nanotube-based field-emission," Review of Scientific
Instruments, Volume 75, No. 10, October 2004; and Choi et al.,
"Development of New X-Ray Source Based on Carbon Nanotube Field
Emission and Application to the Non Destructive Imaging
Technology," IEEE Transactions on Nuclear Science, Vol. 56, No. 3,
June 2009.
[0051] Referring again to FIG. 2A, a tracking system 135 includes
an electromagnetic (EM) sensor system 136 and a shape sensor system
138 for determining the position, orientation, speed, pose, and/or
shape of the distal end portion 126 and of one or more segments 137
along the flexible instrument 120. Although only an exemplary set
of segments 137 is depicted in FIG. 2A, the entire length of the
body 124, between the distal end 128 and the proximal end 130, and
including the end portion 126, may be effectively divided into
segments such that the body 124 is articulable at segment
boundaries. The tracking system 135 may be implemented as hardware,
firmware, software or a combination thereof, which interact with or
are otherwise executed by one or more computer processors, which
may include the processors of the control system 116.
[0052] The EM sensor system 136 includes one or more conductive
coils that may be subjected to an externally generated
electromagnetic field. Each coil of the EM sensor system 136 then
produces an induced electrical signal having characteristics that
depend on the position and orientation of the coil relative to the
externally generated electromagnetic field. In one embodiment, the
EM sensor system 136 may be configured and positioned to measure
six degrees of freedom, e.g., three position coordinates X, Y, Z
and three orientation angles indicating pitch, yaw, and roll of a
base point. Further description of an EM sensor system is provided
in U.S. Pat. No. 6,380,732, filed Aug. 11, 1999, disclosing
"Six-Degree of Freedom Tracking System Having a Passive Transponder
on the Object Being Tracked," which is incorporated by reference
herein in its entirety.
[0053] The shape sensor system 138 includes an optical fiber 140
aligned with the flexible body 124 (e.g., provided within an
interior channel (not shown) or mounted externally). The tracking
system 135 is coupled to a proximal end of the optical fiber 140.
In this embodiment, the fiber 140 has a diameter of approximately
200 .mu.m. In other embodiments, the dimensions may be larger or
smaller.
[0054] The optical fiber 140 forms a fiber optic bend sensor for
determining the shape of the flexible instrument 120. In one
alternative, optical fibers including Fiber Bragg Gratings (FBGs)
are used to provide strain measurements in structures in one or
more dimensions. Various systems and methods for monitoring the
shape and relative position of an optical fiber in three dimensions
are described in U.S. patent application Ser. No. 11/180,389, filed
Jul. 13, 2005, (now abandoned) disclosing "Fiber optic position and
shape sensing device and method relating thereto" claiming benefit
of U.S. Provisional Pat. App. No. 60/588,336 and U.S. Pat. No.
6,389,187, filed on Jun. 17, 1998, disclosing "Optical Fibre Bend
Sensor," which are incorporated by reference herein in their
entireties. In other alternatives, sensors employing other strain
sensing techniques such as Rayleigh scattering, Raman scattering,
Brillouin scattering, and Fluorescence scattering may be suitable.
In other alternative embodiments, the shape of the flexible
instrument 120 may be determined using other techniques. For
example, if the history of the flexible instrument tip's pose is
stored for an interval of time that is smaller than the period for
refreshing the navigation display or for alternating motion (e.g.,
inhalation and exhalation), the pose history can be used to
reconstruct the shape of the flexible instrument 120 over the
interval of time. As another example, historical pose, position, or
orientation data may be stored for a known point of flexible
instrument 120 along a cycle of alternating motion, such as
breathing. This stored data may be used to develop shape
information about the flexible instrument 120. Alternatively, a
series of positional sensors, such as EM sensors 136, positioned
along the flexible instrument 120 can be used for shape sensing.
Alternatively, a history of data from a positional sensor, such as
an EM sensor 136, on the flexible instrument 120 during a procedure
may be used to represent the shape of the flexible instrument 120,
particularly if an anatomical passageway is generally static.
Alternatively, a wireless device with position or orientation
controlled by an external magnetic field may be used for shape
sensing. The history of its position may be used to determine a
shape for the navigated passageways.
[0055] In this embodiment, the optical fiber 140 may include
multiple cores within a single cladding. Each core may be
single-mode with sufficient distance and cladding separating the
cores such that the light in each core does not interact
significantly with the light carried in other cores. In other
embodiments, the number of cores may vary or each core may be
contained in a separate optical fiber.
[0056] In some embodiments, an array of FBGs is provided within
each core. Each FBG comprises a series of modulations of the core's
refractive index so as to generate a spatial periodicity in the
refraction index. The spacing may be chosen so that the partial
reflections from each index change add coherently for a narrow band
of wavelengths, and therefore reflect only this narrow band of
wavelengths while passing through a much broader band. During
fabrication of the FBGs, the modulations are spaced by a known
distance, thereby causing reflection of a known band of
wavelengths. However, when a strain is induced on the fiber core,
the spacing of the modulations will change, depending on the amount
of strain in the core. Alternatively, backscatter or other optical
phenomena that vary with bending of the optical fiber can be used
to determine strain within each core.
[0057] Thus, to measure strain, light is sent down the fiber, and
characteristics of the returning light are measured. For example,
FBGs produce a reflected wavelength that is a function of the
strain on the fiber and its temperature. This FBG technology is
commercially available from a variety of sources, such as Smart
Fibres Ltd. of Bracknell, England. Use of FBG technology in
position sensors for robotic surgery is described in U.S. Pat. No.
7,930,065, filed Jul. 20, 2006, disclosing "Robotic Surgery System
Including Position Sensors Using Fiber Bragg Gratings," which is
incorporated by reference herein in its entirety.
[0058] When applied to a multicore fiber, bending of the optical
fiber induces strain on the cores that can be measured by
monitoring the wavelength shifts in each core. By having two or
more cores disposed off-axis in the fiber, bending of the fiber
induces different strains on each of the cores. These strains are a
function of the local degree of bending of the fiber. For example,
regions of the cores containing FBGs, if located at points where
the fiber is bent, can thereby be used to determine the amount of
bending at those points. These data, combined with the known
spacings of the FBG regions, can be used to reconstruct the shape
of the fiber. Such a system has been described by Luna Innovations.
Inc. of Blacksburg, Va.
[0059] As described, the optical fiber 140 is used to monitor the
shape of at least a portion of the flexible instrument 120. More
specifically, light passing through the optical fiber 140 is
processed by the tracking system 135 for detecting the shape of the
flexible instrument 120 and for utilizing that information to
assist in surgical procedures. The tracking system 135 may include
a detection system for generating and detecting the light used for
determining the shape of the flexible instrument 120. This
information, in turn, can be used to determine other related
variables, such as velocity and acceleration of the parts of a
surgical instrument. By obtaining accurate measurements of one or
more of these variables in real time, the controller 116 can
improve the accuracy of the robotic surgical system and compensate
for errors introduced in driving the component parts. The sensing
may be limited only to the degrees of freedom that are actuated by
the robotic system 100, or may be applied to both passive (e.g.,
unactuated bending of the rigid members between joints) and active
(e.g., actuated movement of the instrument) degrees of freedom.
[0060] The information from the tracking system 135 may be sent to
the navigation system 142 where it is combined with information
from the visualization system 110 and/or the preoperatively taken
images to provide the surgeon or other operator with real-time
position information on the display system 111 for use in the
control of the flexible instrument 120. The control system 116 may
utilize the position information as feedback for positioning the
instrument 120. Various systems for using fiber optic sensors to
register and display an image representing position, orientation
and pose of a surgical instrument with surgical images of
anatomical features are provided in U.S. patent application Ser.
No. 13/107,562, filed May 13, 2011, disclosing, "Medical System
Providing Dynamic Registration of a Model of an Anatomical
Structure for Image-Guided Surgery," which is incorporated by
reference herein in its entirety.
[0061] In the embodiment of FIG. 2A, the instrument 104 is
teleoperated within the tracked instrument system 118. In an
alternative embodiment, the manipulator assembly 102 may be
replaced by direct operator control. In the direct operation
alternative, various handles and operator interfaces may be
included for hand-held operation of the flexible instrument
120.
Tomosynthesis Images from Field Emission X-Rays Produced within the
Body
[0062] FIG. 3 is a generalized longitudinal end view of the distal
end 128 of the end portion 126 having center axis 190 showing
disposition of multiple field emission x-ray devices 181-188
disposed about a circumference of the end portion 126 in accordance
with some embodiments. The end portion 126 is shown as
substantially circular in cross-section and has eight emission
x-ray devices 181-188 distributed at uniform angular displacements
about its circumference, although the end portion 126 need not be
circular in cross section and the emission x-ray devices 181-188
need not be uniformly distributed. The x-ray devices 181-188 are
oriented to emit electrons in a direction to intersect a working
volume as explained more fully below. More particularly, in some
embodiments, in order to facilitate tomosynthesis, the x-ray
devices 181-188 are oriented so that electrons emitted by the
different x-ray devices 181-188 follow paths, which in operation,
are incident upon the working volume adjacent to the distal end 128
of the end portion 126.
[0063] FIGS. 4A-4D are illustrative cross-sectional side views of
the end portion 126 shown in FIG. 3 generally along lines 1-1 (FIG.
4A), lines 2-2 (FIG. 4B), lines 3-3 (FIG. 4C) and lines 4-4 (FIG.
4D) in accordance with some embodiments. X-ray radiation beams
241-248 emitted by the x-ray devices 181-188 are incident upon a
tissue volume 230 disposed within the working volume 232 and are
incident upon one or more x-ray detectors 260, hereinafter referred
to as "detector" 260. The x-ray devices 181-188 can emit radiation
in a prescribed sequence, for example. Of course, the x-ray
radiation beams 241-248 also pass through additional body tissue
while en route between the emission x-ray devices 181-188 and the
detector 260. X-ray image detectors are known to persons of
ordinary skill in the art and will not be described in detail
herein. As explained more fully below, one of the uses of the
system and method disclosed herein is to ascertain the location,
orientation and/or pose of the end portion 126 within a natural or
surgically created anatomical lumen, for example. Another use of
the system and method is to determine whether the tissue volume 230
within the working volume 232 comprises a target tissue volume,
which is an intended target of diagnosis or treatment, for
example.
[0064] FIG. 4A shows a first x-ray radiation beam 241 emitted by a
first emission device 182 mounted upon the end portion 126 at a
first angular position and configured to aim the first x-ray
radiation beam 241 through the tissue volume 230 within the working
volume 232 so as to produce a first 2-D x-ray projection image 255
upon a detector 260 that is indicative of objects disposed along a
path of the first x-ray radiation beam 241 between the end portion
126 and the x-ray detector 260. FIG. 4A also shows a fifth x-ray
radiation beam 245 emitted by a fifth emission device 185 mounted
upon the end portion 126 at a fifth angular position and configured
to aim the fifth x-ray radiation beam 245 through tissue volume 230
within the working volume 232 so as to produce a fifth x-ray image
projection 251 upon the detector 260 that is indicative of objects
disposed along a path of the fifth x-ray radiation beam 245 between
the end portion 126 and the x-ray detector 260.
[0065] FIG. 4B shows a second x-ray radiation beam 242 emitted by a
second emission device 182 mounted upon the end portion 126 at a
second angular position configured to aim the second x-ray
radiation beam 242 through the tissue volume 230 within the working
volume 232 so as to produce a second 2-D x-ray projection image 252
upon the detector 260 that is indicative of objects disposed along
a path of the second x-ray radiation beam 242 between the end
portion 126 and the x-ray detector 260. FIG. 4B also shows a sixth
x-ray radiation beam 246 emitted by a sixth emission device 186
mounted upon the end portion 126 at a sixth angular position and
configured to aim a sixth x-ray radiation beam 246 through tissue
volume 230 within the working volume 232 so as to produce a sixth
x-ray image projection 256 upon the detector 260 that is indicative
of objects disposed along a path of the sixth x-ray radiation beam
246 between the end portion 126 and the x-ray detector 260.
[0066] FIG. 4C shows a third x-ray radiation beam 243 emitted by a
third emission device 183 mounted upon the end portion 126 at a
third angular position and configured to aim the third x-ray
radiation beam 243 through the tissue volume 230 within the working
volume 232 so as to produce a third 2-D x-ray projection image 253
upon the detector 260 that is indicative of objects disposed along
a path of the third x-ray radiation beam 243 between the end
portion 126 and the x-ray detector 260. FIG. 4C also shows a
seventh x-ray radiation beam 247 emitted by a seventh emission
device 187 mounted upon the end portion 126 at a seventh angular
position and configured to aim the seventh x-ray radiation beam 247
through tissue volume 230 within the working volume 232 so as to
produce a seventh x-ray image projection 257 upon the detector 260
that is indicative of objects disposed along a path of the seventh
x-ray radiation beam 247 between the end portion 126 and the x-ray
detector 260.
[0067] FIG. 4D shows a fourth x-ray radiation beam 244 emitted by a
fourth emission device 184 mounted upon the end portion 126 at a
fourth angular position 192 and configured to aim the fourth x-ray
radiation beam 244 through the tissue volume 230 within the working
volume 232 so as to produce a fourth 2-D x-ray projection image 254
upon the detector 260 that is indicative of objects disposed along
a path of the fourth x-ray radiation beam 244 between the end
portion 126 and the x-ray detector 260. FIG. 4D also shows an
eighth x-ray radiation beam 248 emitted by an eighth emission
device 188 mounted upon the end portion 126 at an eighth angular
position and configured to aim the eighth x-ray radiation beam 248
through tissue volume 230 within the working volume 232 so as to
produce an eighth x-ray image projection 258 upon the detector 260
that is indicative of objects disposed along a path of the eighth
x-ray radiation beam 248 between the end portion 126 and the x-ray
detector 260.
[0068] It will be appreciated of course that greater or fewer than
eight emission devices 181-188 may be employed and that greater or
fewer than eight 2-D x-ray projection images 251-258 may be
produced. Also, the angular displacements need not be uniform, for
example.
[0069] FIG. 5 is an illustrative drawing representing spatial
disposition of the eight 2-D x-ray projection images 251-258 of
FIGS. 4A-4D in accordance with some embodiments. Each 2-D x-ray
projection image is produced by passing x-ray radiation, along a
different beam path, through the tissue volume 230 within the
working volume 232. It will be appreciated that the working volume
232 is approximately centered on the center axis of the end portion
126 generally in the middle of the multiple projections.
[0070] FIG. 6 is an illustrative drawing showing multiple
tomosynthesis images 270a-270d generated by the visualization
system 110 based upon the x-ray projection images 251-258 in
accordance with some embodiments. More particularly, one or more
processors are configured to convert the multiple 2-D projection
images 251-258 to tomosynthesis images 270a-270d. It will be
appreciated that although eight 2-D projection images and four
tomosynthesis images are shown, a greater or lesser number of 2-D
projection images and/or tomosynthesis images may be provided. Each
example tomosynthesis image slice 271a-271d represents an image
slice at a different Z-direction depth within the tissue volume
230. In the illustrated embodiment, a set of four tomosynthesis
images 270a-270d are shown, although it will be appreciated that
greater or fewer than four tomosynthesis images may be produced. In
general, the spacing and the number of tomosynthesis images can be
selected based on factors such as depth (e.g., in a Z-direction
parallel to the axis 190), resolution, or a range of depths desired
to be covered by the tomosynthesis images.
[0071] Tomosynthesis, also referred to as digital tomosynthesis
(DTS), is a method for performing high-resolution limited-angle
tomography. More specifically, tomosynthesis is a process used to
reconstruct three dimensional (3-D) images based upon a limited set
of two dimensional (2-D) scans. As used herein, the term
"tomosynthesis image" or "tomosynthesis slice" refers to an image
created using a number of 2-D projection images, where the number
of 2-D projection images (input images) used to produce a
tomosynthesis image is less than that needed for computed
tomography (CT) image reconstruction. In some embodiments,
producing tomosynthesis images from 2-D projections involves a
technique commonly referred to as filtered back projection.
[0072] Generally speaking, each of the tomosynthesis images
270a-27d is constructed by determining a plurality of voxels,
wherein each voxel is determined by considering indicia of x-ray
beam attenuation associated with that voxel in each of the 2-D
projection images 251-258. As used herein, a voxel (volumetric
pixel or volumetric picture element) is a volume element,
representing a value on a regular grid in three-dimensional space.
Indicia of attenuation are accumulated from all 2-D projection
images 251-258 to estimate the attenuation of a given voxel. The
attenuation of a voxel is partly represented by an intensity value
of its corresponding pixel in each projection image. By
accumulating the values of pixels from all projection images
251-258 that correspond to a given voxel, the effect of attenuation
at that voxel is constructively accumulated.
[0073] Determinations of pixel positions and values for each of the
2-D projection images 251-258 for use in voxel determinations can
be made using known x-ray photogrammetry techniques and geometry
calculations based upon the position of the (one or more) x-ray
detector 260 relative to each of the x-ray emission devices
181-188, for example. It will be appreciated that the x-ray
emission devices 181-188 are disposed within an anatomical lumen
and that the detector 260 typically is disposed outside of the
body, although in some embodiments, an x-ray detector may be
disposed within a body lumen in a spaced relation to one or more
x-ray emission devices.
[0074] The relative positions of the emission devices 181-188 and
the detector(s) 260 can be readily determined. For example, as
explained above, in some embodiments, an EM sensor system 136
and/or a shape sensor system 138 can be used to determine the
position and orientation of the end portion 126 relative to the
interface 122. For example, a location of the interface 122 is
known, and therefore a location of the end portion 126 relative to
the interface 122 can be determined to within an acceptable amount
of precision. As explained below, small errors in sensed location
of the end portion 126 may arise due to natural body motion such as
breathing, for example. Referring to FIG. 2A, a position and
orientation of the detector 260 relative to the interface 122 can
be determined, for example, through physical dimensions and
physical disposition, relative to the interface 122, of structures
261 on which the detector 260 is mounted, for example. These
determined positions and orientations of the end portion 126 and
the detector 260 can be used, for example, to align the one or more
detector 260 with the emission devices 181-188 so as to capture
x-ray radiation emitted by the devices 181-188. In some
embodiments, particularly where tomosynthesis is employed, the (one
or more) detector 260 is disposed to capture multiple x-ray
radiation beams 241-248 that diverge from each other following
their incidence upon a region of the body.
[0075] In practice, blurring of reconstructed the tomosynthesis
images 270a-27d may result since voxels may be accumulated in a
non-constructive fashion. Various methods can be performed to
address this blurring. In some embodiments, tomosynthesis images
can be de-blurred by performing back projection combined with
filtering. De-blurred tomosynthesis images generated based on
filtered back projection can be based on inverse of Radon transform
using the back-projection theorem, for example. Tomosynthesis
techniques are well known to persons of ordinary skill in the art
and will not be further described herein. See, for example, T. Gomi
et al., X-ray digital linear tomosynthesis imaging, J. Biomedical
Science and Engineering, 2011, 4, 443-453, published online June
2011 (www.SciRP.org/journal/jbise/). Also see, for example, U.S.
Pat. No. 7,532,705, filed Apr. 10, 2007, entitled, "System and
Method for Localizing a Target for Radiotherapy based on Digital
Tomosynthesis"; and U.S. Pat. No. 7,711,087, filed Apr. 7, 2006,
entitled, "Patient Setup using Tomosynthesis Techniques," which are
expressly incorporated herein in their entirety by this
reference.
Similarity Comparison Between Tomosynthesis Image and 2-D Reference
Images
[0076] FIG. 7 is an illustrative drawing representing a 2-D
reference image slice 780 selected from a 3-D reference computed
tomography image 782 that include a feature 781, such as an
anatomical landmark, for matching with one or more tomosynthesis
image slices in accordance with some embodiments. The 3-D reference
computed tomography (CT) image 782, which is sometimes referred to
as a "planning" CT image, is obtained for a portion of a patient's
body during a diagnostic session, for example, in which the patient
is diagnosed, or in a treatment planning session in which a
treatment plan is determined, for example. In some embodiments, the
3-D reference CT image 782 can be obtained by using a CT machine
(not shown) to deliver diagnostic radiation energy towards the
patient at a multiplicity of angles so as to generate image data at
different angles, which are then processed to reconstruct a
three-dimensional CT image. Computed tomography is a well-known
technique to persons of ordinary skill in the art and will not be
further described herein.
[0077] In some embodiments, one or more processors are configured
to compare one or more of the tomosynthesis images 270a-270d with a
2-D reference image slice 780 to determine an offset between a
detected and predicted poses of the end portion 126. Hereinafter,
an instrument pose that is determined using the tracking system 135
shall be referred to as a "predicted" pose. A thickness of the 2-D
reference image slice 780 can be selected to be approximately the
same as the depth resolution of the tomosynthesis images 270a-270d,
thus making the 2-D reference image slice 780 and tomosynthesis
images 270a-270d more compatible for comparison. In particular, the
display system 111 can be used to display a reference image slice
780 and one or more tomosynthesis images 270a-270d. A determination
is made as to one or more 2-D reference images that best match one
or more of the tomosynthesis images. Estimation then can be made as
to an offset between a matching 2-D reference image and the
tomosynthesis images. It will be appreciated that the location
within the patient's body of landmarks within the 2-D reference
image are known with precision since the 2-D reference images are
taken from the 3-D image information produced using a precision
technique such as CT. More particularly, based upon such
comparison, an estimated offset can be determined between the
detected and predicted end portion poses.
[0078] FIG. 8 is an illustrative drawing representing a detected
tomosynthesis image 270b and a 2-D reference image 280 for
comparison in accordance with some embodiments. Landmarks such as
bone or soft tissue volumes or another fiducial represented in
multiple 2-D reference images can be compared with landmarks
represented in the tomosynthesis images in order to identify the
best match.
[0079] FIG. 9 is an illustrative simplified drawing of an example
screen display showing multiple 2-D reference slices 287 alongside
a selected tomosynthesis slice 271b in accordance with some
embodiments. The visualization system 110 displays, on the display
system 111, one or more tomosynthesis images representing the
determined actual working volume together with one or more 2-D
reference images so that a physician can make an assessment as to
which 2-D reference image best matches the tomosynthesis images.
The physician can thereby make a better determination of an actual
current location of the working volume within a patient's body, and
therefore, make a better determination of the position and/or
orientation of the end portion 126 to bring an intended target
tissue volume into alignment with the working volume. In other
words, a physician or other operator can determine an offset
between determined and predicted positions of the working volume
through comparison of one or more tomosynthesis images with one or
more 2-D reference images. It will be appreciated that although
multiple different 2-D reference slices 287 are shown in FIG. 9, in
an alternative embodiment, reference slices may be displayed
individually in sequence as a physician pans across 2-D reference
slice data or as the physician scrolls through the data, for
example.
Similarity Comparison Between 2-D Projected Images and 2-D
Reference Images
[0080] FIG. 10 is an illustrative drawing of an alternative
embodiment of the end portion 126 in which the emission devices
181-184 are arranged to emit x-ray radiation beams in a direction
generally parallel to the center axis of the end portion 126. The
parallel x-ray radiation beams 290 penetrate the working volume
232, and a 2-D projection image 294 that includes feature 293 is
captured by the detector 260 aligned with the x-ray radiation beams
290. In some embodiments, the projection image 294 is displayed
using the display system 111, which can be viewed by a physician or
other operator for comparison the 2-D projection image 294 with one
or more 2-D reference slices. The position and/or orientation
and/or shape of the instrument 104 can be changed as needed to more
accurately navigate the instrument 104 within the patient's body
and/or to align the working volume 232 with an intended target
tissue volume, for example.
Emission Devices Configured to Intersect Displaced from the End
Portion
[0081] FIG. 11 is an illustrative drawing representing an
alternative embodiment showing an end portion 1102 having x-ray
emission devices 1104-1, 1104-2 (only two shown) configured to emit
x-ray beams 1106-1, 1106-2 that intersect body tissue a location
that is displaced from a working volume 1110. One or more detector
260 is disposed outside of the patient's body 1112 to capture the
beams 1106-1, 1106-2. The beams 1106-1, 1106-2 are configured so as
to intersect with tissue that is aligned with an axis 1114 of the
end portion 1102. Thus, 2-D projection images produced by the beams
1106-1, 1106-2 represent a viewpoint of a portion of body tissue
aligned with the axis 1114 of the end portion 1102. It will be
appreciated that the process described with reference to FIG. 11
can use the captured x-ray image information to identify and
correct discrepancies between detected and predicted end portion
poses.
Machine-Implemented Process to Compare Field Emission Images with
Reference Images
[0082] In some embodiments, one or more processors are configured
to compare detected x-ray image information with reference x-ray
image information to determine the actual position and orientation
of an instrument end portion 126 within a patient's body. There can
be a discrepancy or error, albeit a small one, between an actual
pose and a predicted pose of the end portion 126. Such an error may
result from the dynamic nature of certain anatomic structures such
as the lungs or the heart. For example, inhalation and exhalation
change the position and size of the bronchial passageways of the
lung. Alternatively, the error may result from tissue deformation
caused by the presence of the surgical instrument 104 within the
anatomic passageways. In some situations, even a small discrepancy
between predicted and actual position and/or orientation of the end
portion 126 can be problematic, particularly if the instrument 104
is navigating through narrow or closely spaced anatomical passages
or if a target tissue volume is especially small. Moreover, some
target tissue volumes may be on the order of one millimeter in
diameter or less, for example. As a consequence, the instrument 104
may sometimes become located within the wrong passage.
Alternatively, for example, a discrepancy between the predicted and
determined end portion pose can result in an intended target tissue
volume not being disposed within the actual working volume. As a
result of such discrepancy, the effector 132 may not be properly
aligned to obtain a tissue sample from the intended target volume
or to deliver a therapy or medicine to the intended target volume,
for example.
[0083] FIG. 12 is an illustrative flow diagram representing a
process to search for similarity between detected 2-D x-ray images
and one or more 2-D reference x-ray images in accordance with some
embodiments. Operation 1202 configures one or more processors to
determine a predicted position and orientation of the end portion
126. A sensed position and orientation of the end portion 126
within a patient's body are determined using the tracking system
135. In accordance with some embodiments, the electromagnetic (EM)
sensor system 136 and the shape sensor system 138 can be used for
determining the approximate position, orientation, speed, pose,
and/or shape of the end portion 126. In addition, the image capture
element 134 can be used to provide a visual indication of the
approximate position of the end portion 126 from a perspective
internal to the patient's body. U.S. patent application Ser. No.
13/893,040, filed on May 13, 2013, (Docket No. ISGR 04290/PROV/US
(70228.126), entitled "Systems and Methods for Registration of a
Medical Device Using a Reduced Search Space," which is expressly
incorporated herein in its entirety by this reference, discloses
further details of a system and method for tracking a medical
device within a patient anatomy during a medical procedure.
[0084] Operation 1204 configures one or more processors to
determine a predicted matching 2-D reference image that corresponds
to the predicted position and orientation of the end portion 126.
The predicted matching 2-D reference image can be extracted from
the 3-D reference information. A predicted x-ray beam path along
the axis 190 of the end portion 126 disposed in the predicted
position and orientation is used to identify and select the
predicted 2-D reference image, which includes x-ray attenuation
information corresponding to a portion of the patient's body from a
viewpoint along that predicted path. In some embodiments, the x-ray
attenuation information includes an attenuation pattern that is
indicative of anatomical structures that the x-ray radiation has
passed through en route to detection.
[0085] Operation 1206 configures one or more processors to
configure the x-ray emission devices to emit x-ray radiation along
a path that is incident upon a patient tissue. The x-ray emission
path, which extends between the devices 181-188 and the detector
260, includes the working volume 232. The detector 260 captures 2-D
projection images that contain x-ray attenuation information
indicative of structures disposed along the emission path. Since
there may be some discrepancy between the actual and predicted pose
of the end portion 126, some adjustment of the position of the
detector 260 may be needed to capture the emitted radiation. The
location of the predicted 2-D reference frame can be used as a
predictor of the x-ray emission path in making such
adjustments.
[0086] Operation 1208 configures one or more processors to search
for similarity between detected 2-D image information and 2-D
reference image information obtained from the 3-D reference image
information. The detected 2-D image information may comprise 2-D
projection information or tomosynthesis information. In some
embodiments, the search may involve configuring the control system
116 to perform an automated comparison of the detected 2-D image
information and the 2-D reference image information. In particular,
x-ray attenuation information from the detected 2-D image
information is compared with x-ray attenuation information from the
3-D reference image information to identify a 2-D reference image
that has sufficient similarity to the detected 2-D image to
determine that there is a match. More particularly, the control
system 116 is configured to identify a best match between the
detected 2-D image information and one or more 2-D reference
images. The predicted matching 2-D reference image can be used as a
starting point within the 3-D image data for the similarity search.
In embodiments, the search can cover some prescribed region within
the 3-D image data about the predicted matching 2-D reference
image. Alternatively, or in addition to the automated search, a
surgeon or other technician may use the display system 111 to
display both detected 2-D image information and 2-D reference image
information for visual comparison to find a best match.
[0087] Decision operation 1210 configures one or more processors to
determine whether a match is identified within the search region
based upon a prescribed threshold level of similarity between the
detected image information and 2-D reference image. Such match
determination can be performed automatically through configuration
of the control system 116 or can be performed manually through
visual observation using display system 111. In response to a
determination by decision operation 1210 that a match is
identified, operation 1212 determines an estimated offset between
actual and predicted poses of the end portion 126. Operation 1214
configures one or more processors to change a pose of the end
portion 126 based at least in part upon the estimated offset. The
change in end portion pose may be achieved manually through user
actuation of the manipulator assembly 102 while receiving visual
cues in the form of detected and reference x-ray images on the
visualization system 110, for example. The process ends following
the change in end portion pose.
[0088] In response to a determination by decision operation 1210
that no a match is identified within the search region, decision
operation 1216 configures one or more processors to determine
whether to increase the search region. In some embodiments, the
search region may be increased incrementally up to some prescribed
limit. In response to a determination to increase the search
region, the operation 1218 configures one or more processors to
enlarge the search region and directs the control flow of the
process 1200 back to operation 1208. In response to a determination
by decision operation 1216 to not increase the search region,
operation 1218 reports an error and the process 1200 ends.
Examples of Different End Position Pose Offsets
[0089] FIGS. 13A-13B are illustrative drawings showing two
different offsets between predicted and actual poses of the end
portion 126 of the medical instrument in accordance with some
embodiments. FIG. 13A shows the predicted and detected positions of
the end portion 126 offset by a distance "A". The end portion 126
disposed within a patient's body 1303 in a pose in which detected
x-ray beams that follow a first emission path 1302-1 and that
produce detected 2-D image information that is captured by the
detector 260. Dashed lines 126-1 represent a predicted pose of the
end portion 126 in which first predicted x-ray beams indicated by
dashed lines follow a first predicted path 1304-1 that corresponds
to a predicted 2-D reference image. Operation 1204 (FIG. 12) can be
used to determine the predicted 2-D reference image 280, as
explained above. In accordance with operation 1208, a search is
conducted within a search region of 3-D image information,
indicated by dashed lines 1303-1, to identify a best match between
the detected image data and the reference image data.
[0090] FIG. 13B shows the predicted and detected poses of the end
portion 126 offset by an angle "B". Dashed lines 126-2 represent a
predicted pose of the end portion 126 in which second predicted
x-ray beams follow a second predicted path 1304-2 that corresponds
to a predicted 2-D reference image. Operation 1204 (FIG. 12) can be
used to determine the predicted 2-D reference image, as explained
above. In accordance with operation 1208, a search may be conducted
within a search region of 3-D image information, which is indicated
by dashed lines 1303-2, to identify a best match between the
detected image data and the reference image data.
Anatomical Examples
[0091] FIG. 14A is an illustrative drawing representing a composite
image 1400 including an image 1402 of a human lung 1404, from a
viewpoint external to the lung 1404, registered with an instrument
image 1406 of a flexible instrument, such as the flexible
instrument 120, in accordance with some embodiments. The image 1402
of the lung 1404 may be generated from preoperatively recorded
images or may be generated concurrently during the surgical
procedure. The composite image 1400 may be displayed via display
system 111. As the instrument 120 is advanced through bronchial
passageways 1408 of the lung 1404, information from the tracking
system 135 and/or the visualization system 110 can be used to
register the instrument image 1406 with the lung image 1402. The
image 1402 of the lung 1404 may change, for example, to depict the
lung 1404 in a state of inspiration or expiration. The instrument
image 1406 may change to depict the advancement or withdrawal of
the instrument 120 through the bronchial passageways 1408. In this
example, a target tissue volume "X" is the intended target of a
surgical procedure.
[0092] It will be appreciated that visual navigation within
bronchial passages can be impractical due to mucous or other opaque
fluids. Also, visual identification of the target tissue X volume
may be impossible when such volume is disposed in an interstitial
location not directly accessible to a bronchial passage. Moreover,
sonic position sensing may not be practical because the instrument
body 124 may be within a volume containing air or other fluid and
not in contact with actual tissue.
[0093] FIG. 15 is an illustrative drawing representing an internal
image 1520 of the human lung 1404 depicting a region 1522 of the
lung 1404 from the viewpoint along a center of the end portion 126
the instrument 120 in accordance with some embodiments. The image
1520 may be a concurrent visual image taken using image capture
element 134 during the surgical procedure by the instrument 120
while located in the depicted portion of the lung 1404. More
specifically, the image 1520 may be captured by the visualization
system 110. Alternatively, the image 1520 may be a preoperatively
recorded image selected based upon the location of the tip of the
instrument 120 as determined by the tracking system 135.
[0094] FIG. 14B is an illustrative drawing showing an example of an
instrument heading down the wrong anatomical passage. More
particularly, FIG. 14B shows the composite image 1400 of FIG. 14A
and also shows a first example discrepancy between first detected
(actual) and predicted poses of the end portion 126 and
corresponding detected (actual) and predicted working volume
locations 1432, 1434 in accordance with some embodiments. FIG. 14B
includes an enlarged view 1430 of a portion of the lung 1404 that
includes first and second bronchial passages 1408-1, 1408-2,
respectively. The end portion 126 is shown disposed at an entry to
the first bronchial passage 1408-1. The actual working volume 1432
is shown adjacent the end portion 126. The target tissue volume X
is disposed adjacent to a wall of the second bronchial passage
1408-2. Thus, the end portion 126 is erroneously headed down the
wrong passage. A sensed position of the instrument 120 and its end
portion 126 are indicated by dashed lines 120' and 126',
respectively.
[0095] Still referring to FIG. 14B, a sensed pose of the instrument
120 end portion 126 indicated by dashed lines 120', 126' is
determined in accordance with operation 1202 (FIG. 12). A predicted
2-D reference image 1480 is determined based upon predicted x-ray
emission path 1440 in accordance with operation 1204. The end
portion 126 mounted emission devices 181-188 emit x-ray radiation
1436 that is captured by the detector 260 in accordance with
operation 1206. The x-ray radiation 1436 is attenuated by lung
tissue and other body structures, such as a rib 1438, disposed
between the emission devices 181-188 and the detector 260. The
detected x-ray image information is compared with 2-D reference
x-ray image information from a 3-D reference image source. The
predicted 2-D reference image 1480 can be used as a starting point
in a search for a match. The detected (actual) pose of the end
portion 126 can be changed to align with the predicted pose
indicated by dashed lines 120', 126'.
[0096] FIG. 14C is an illustrative drawing showing an example of an
instrument that is misaligned with respect to an intended target
tissue volume. More particularly, FIG. 14C shows the composite
image 1400 of FIG. 14A and also shows a second example discrepancy
between second detected (actual) and predicted poses of the end
portion 126 and corresponding detected (actual) and predicted
working volume locations 1452, 1454 in accordance with some
embodiments. FIG. 14C includes an enlarged view 1450 of a portion
of the lung 1404 that includes the first and second bronchial
passages 1408-1, 1408-2, respectively. The end portion 126 is shown
disposed within the second bronchial passage 1408-2. However, the
actual working volume 1454 adjacent the end portion 126 does not
encompass any portion of the target tissue volume X. A sensed
position of the instrument 120 and its end portion 126 is indicated
by dashed lines 120'' and 126'', respectively. It can be seen that
in this example, the predicted working volume location 1454 does
overlap with the target tissue volume X. Thus, it can be seen that
there is a discrepancy between locations of the actual and
predicted working volumes.
[0097] Continuing to refer to FIG. 14C, a sensed pose of the
instrument 120 end portion 126 indicated by dashed lines 120'',
126'' is determined in accordance with operation 1202. A predicted
2-D reference image 1490 is determined based upon predicted x-ray
emission path 1460 in accordance with operation 1204. The end
portion 126 mounted emission devices 181-188 emit x-ray radiation
1456 that is captured by the detector 260 in accordance with
operation 1206. The x-ray radiation 1456 is attenuated by lung
tissue and other body structures, such as a rib 1438, disposed
between the emission devices 181-188 and the detector 260. The
detected x-ray image information is compared with 2-D reference
x-ray image information from a 3-D reference image source. The
predicted 2-D reference image 1490 can be used as a starting point
in a search for a match. The detected (actual) pose of the end
portion 126 can be changed to align with the predicted pose
indicated by dashed lines 120'' and 126''.
Computer Hardware and Storage Devices
[0098] FIG. 16 shows an illustrative diagrammatic representation of
a more particularized computer system 1600, in an example form,
controller 116 and display system in accordance with some
embodiments. The computer system 1600 can be configured to
implement, for example, the control system 116 and the display
system 111. In alternative embodiments, the computer system 1600
operates as a standalone device or may be connected (e.g.,
networked) to other machines. In a networked deployment, the
computer system 1600 may operate in the capacity of a server or a
client machine in server-client network environment, or as a peer
machine in a peer-to-peer (or distributed) network environment. The
computer system 1600 may be a server computer, a client computer, a
personal computer (PC), a tablet PC, a set-top box (STB), a
Personal Digital Assistant (PDA), a cellular telephone, a web
appliance, a network router, switch or bridge, or any machine
capable of executing a set of instructions (sequential or
otherwise) that specify actions to be taken by that machine.
Further, while only a single machine (i.e., computer system 1600)
is illustrated, the term "machine" shall also be taken to include
any collection of machines that individually or jointly execute a
set (or multiple sets) of instructions to perform any one or more
of the methodologies discussed herein.
[0099] The example computer system 1600 includes a processor 1602
(e.g., a central processing unit (CPU), a graphics processing unit
(GPU), or both), a main memory 1604 and a static memory 1606, which
communicate with each other via a bus 1608. The computer system
1600 may further include a video display unit 1610 (e.g., liquid
crystal display (LCD), organic light emitting diode (OLED) display,
touch screen, or a cathode ray tube (CRT)) that can be used to
display positions of the surgical instrument 104 and flexible
instrument 120, for example. The computer system 1600 also includes
an alphanumeric input device 1612 (e.g., a keyboard, a physical
keyboard, a virtual keyboard using software), a cursor control
device or input sensor 1614 (e.g., a mouse, a track pad, a
trackball, a sensor or reader, a machine readable information
reader, bar code reader), a disk drive unit 1616, a signal
generation device 1618 (e.g., a speaker) and a network interface
device or transceiver 1620.
[0100] The disk drive unit 1616 includes a non-transitory
machine-readable storage device medium 1622 on which is stored one
or more sets of instructions 1624 (e.g., software) embodying any
one or more of the methodologies or functions described herein,
such as the processes of FIGS. 12 and 13A-13B. The instructions
1624 may also reside, completely or at least partially, within the
main memory 1604, static memory 1606 and/or within the processor
1602 during execution thereof by the computer system 1600, the main
memory 1604 and the processor 1602 also constituting non-transitory
machine-readable storage device media. The non-transitory
machine-readable storage device medium 1622 also can store an
integrated circuit design and waveform structures.
[0101] The instructions 1624 may further be transmitted or received
over a network 1626 via the network interface device or transceiver
1620.
[0102] While the machine-readable storage device medium 1622 is
shown in an example embodiment to be a single medium, the term
"machine-readable medium," "computer readable medium," and the like
should be taken to include a single medium or multiple media (e.g.,
a centralized or distributed database, and/or associated caches and
servers) that store the one or more sets of instructions 1624. The
term "machine-readable medium" shall also be taken to include any
medium that is capable of storing, encoding or carrying a set of
instructions for execution by the machine and that cause the
machine to perform any one or more of the methodologies of the
present disclosure. The term "machine-readable medium" shall
accordingly be taken to include, but not be limited to, solid-state
memories, optical and magnetic media, and carrier wave signals.
[0103] It will be appreciated that, for clarity purposes, the above
description describes some embodiments with reference to different
functional units or processors. However, it will be apparent that
any suitable distribution of functionality between different
functional units, processors or domains may be used without
detracting from the present disclosure. For example, functionality
illustrated to be performed by separate processors or controllers
may be performed by the same processor or controller. Hence,
references to specific functional units are only to be seen as
references to suitable means for providing the described
functionality, rather than indicative of a strict logical or
physical structure or organization.
[0104] Although the present disclosure has been described in
connection with some embodiments, it is not intended to be limited
to the specific form set forth herein. One skilled in the art would
recognize that various features of the described embodiments may be
combined in accordance with the present disclosure. Moreover, it
will be appreciated that various modifications and alterations may
be made by those skilled in the art without departing from the
spirit and scope of the present disclosure.
[0105] In addition, in the foregoing detailed description, it can
be seen that various features are grouped together in a single
embodiment for the purpose of streamlining the disclosure. This
method of disclosure is not to be interpreted as reflecting an
intention that the claimed embodiments require more features than
are expressly recited in each claim. Rather, as the following
claims reflect, inventive subject matter lies in less than all
features of a single disclosed embodiment. Thus the following
claims are hereby incorporated into the detailed description, with
each claim standing on its own as a separate embodiment.
[0106] The foregoing description and drawings of embodiments in
accordance with the present invention are merely illustrative of
the principles of the inventive subject matter. Therefore, it will
be understood that various modifications can be made to the
embodiments by those skilled in the art without departing from the
spirit and scope of the inventive subject matter, which is defined
in the appended claims.
[0107] Although the systems and methods of this disclosure have
been illustrated for use in the connected bronchial passageways of
the lung, they are also suited for navigation and treatment of
other tissues, via natural or surgically created connected
passageways, in any of a variety of anatomical systems including
the digestive system, colon, the intestines, the kidneys, the
brain, the heart, the circulatory system, or the like. The methods
and embodiments of this disclosure are also suitable for
non-surgical applications.
[0108] Thus, while certain exemplary embodiments of the invention
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 inventive subject matter, and that
the embodiments of the invention not be limited to the specific
constructions and arrangements shown and described, since various
other modifications may occur to those ordinarily skilled in the
art.
* * * * *