U.S. patent application number 16/792697 was filed with the patent office on 2020-07-09 for systems and methods for interventional procedure planning.
The applicant listed for this patent is INTUITIVE SURGICAL OPERATIONS, INC.. Invention is credited to Dorin Panescu, Tao Zhao.
Application Number | 20200214664 16/792697 |
Document ID | / |
Family ID | 51017972 |
Filed Date | 2020-07-09 |
United States Patent
Application |
20200214664 |
Kind Code |
A1 |
Zhao; Tao ; et al. |
July 9, 2020 |
SYSTEMS AND METHODS FOR INTERVENTIONAL PROCEDURE PLANNING
Abstract
A method of deploying an interventional instrument is performed
by a processing system. The method comprises receiving an image of
an anatomic structure from an imaging probe. The image has an image
frame of reference. The imaging probe is extendable distally beyond
a distal end of a guide catheter. The distal end of the guide
catheter has a catheter frame of reference. The method further
includes receiving location data associated with a target structure
identified in the image. The received location data is in the image
frame of reference. The method further comprises transforming the
location data associated with the target structure from the image
frame of reference to the catheter frame of reference.
Inventors: |
Zhao; Tao; (Sunnyvale,
CA) ; Panescu; Dorin; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTUITIVE SURGICAL OPERATIONS, INC. |
SUNNYVALE |
CA |
US |
|
|
Family ID: |
51017972 |
Appl. No.: |
16/792697 |
Filed: |
February 17, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14144186 |
Dec 30, 2013 |
10588597 |
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16792697 |
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61747920 |
Dec 31, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 34/10 20160201;
A61B 8/0841 20130101; A61B 8/085 20130101; A61B 8/4263 20130101;
A61B 10/04 20130101; A61B 2034/107 20160201; A61B 8/4245 20130101;
A61B 2034/102 20160201; A61B 17/00234 20130101; A61B 2090/364
20160201; A61B 2034/2051 20160201; A61B 5/065 20130101; A61B 8/12
20130101; A61B 5/0066 20130101 |
International
Class: |
A61B 8/12 20060101
A61B008/12; A61B 8/00 20060101 A61B008/00; A61B 34/10 20060101
A61B034/10; A61B 8/08 20060101 A61B008/08; A61B 10/04 20060101
A61B010/04; A61B 17/00 20060101 A61B017/00 |
Claims
1-20. (canceled)
21. A method of deploying an interventional instrument, the method
comprising: identifying a target structure in an anatomic frame of
reference; determining a target region in the anatomic frame of
reference with respect to a current location of the interventional
instrument wherein determining the target region includes
determining a probability of a location of the target structure
relative to the current location of the interventional instrument;
and recording a first engagement location of the interventional
instrument within the target region.
22. The method of claim 21 wherein at least a portion of the target
structure is located within the target region.
23. The method of claim 21 wherein the anatomic frame of reference
is a three-dimensional anatomic frame of reference and wherein
identifying the target structure includes identifying a model
target structure in a three-dimensional model frame of reference
and registering the three-dimensional model frame of reference to
the three-dimensional anatomic frame of reference.
24. The method of claim 21 wherein determining the target region
includes at least one of determining a change in a patient
anatomical pose between a preoperative imaging time and an
interventional procedure time, determining an uncertainty value for
a sensor in the interventional instrument, determining an
uncertainty value associated with a shape of a target anatomic
structure, determining a value associated with a property of tissue
surrounding the target structure, and visualizing a target anatomic
structure with an imaging device.
25. The method of claim 21 wherein the interventional instrument
includes a catheter and a tool and determining the target region
includes determining an uncertainty value for a known
characteristic of the tool extended from the catheter.
26. The method of claim 21 further comprising providing
instructions for timing conduct of a first engagement procedure at
the first engagement location based on a cyclical anatomical motion
state.
27. The method of claim 21 further comprising identifying a second
engagement location for deploying the interventional
instrument.
28. The method of claim 27 further comprising determining a revised
target region in the anatomic frame of reference based on
information gathered from the first engagement location.
29. The method of claim 28 wherein the second engagement location
is located within the revised target region.
30. The method of claim 21 further comprising recording a second
engagement location of the interventional instrument within the
target region.
31. The method of claim 30 further comprising providing
instructions for conducting a second engagement procedure at the
second engagement location based on information obtained from the
first engagement location.
32. The method of claim 30 further comprising determining a first
deployment location for the interventional instrument prior to
recording the first engagement location; and determining a second
deployment location for the interventional instrument prior to
recording the second engagement location, wherein the first
deployment location is different from the second deployment
location.
33. A system comprising: an interventional instrument including a
catheter and a tool deployable from the catheter; and a control
system configured to: identify a target structure in an anatomic
frame of reference; determine a target region in the anatomic frame
of reference with respect to a current location of the
interventional instrument, wherein determining the target region
includes determining a probability of a location of the target
structure relative to the current location of the interventional
instrument; and record a first engagement location of the
interventional instrument within the target region.
34. The system of claim 33 wherein the anatomic frame of reference
is a three-dimensional anatomic frame of reference and wherein
identifying the target structure includes identifying a model
target structure in a three-dimensional model frame of reference
and registering the three-dimensional model frame of reference to
the three-dimensional anatomic frame of reference.
35. The system of claim 33 wherein determining the target region
includes at least one of determining a change in a patient
anatomical pose between a preoperative imaging time and an
interventional procedure time, determining an anatomical motion
cycle, determining an uncertainty value for a characteristic of the
tool extended from the catheter, determining an uncertainty value
associated with a shape of a target anatomic structure, and
visualizing a target anatomic structure with an imaging device.
36. The system of claim 35 wherein the anatomical motion cycle is a
respiration cycle.
37. The system of claim 33 wherein the control system is further
configured to provide instructions for when to conduct a first
engagement procedure at the first engagement location based on a
cyclical anatomical motion state.
38. The system of claim 33 wherein the control system is configured
to: record a second engagement location of the interventional
instrument within the target region.
39. The system of claim 38 wherein the control system is further
configured to provide instructions for conducting a second
engagement procedure at a second engagement location based on
information obtained from the first engagement location.
40. The system of claim 33 wherein the control system is further
configured to generate a graphical user interface (GUI) including a
target marker representing the target structure.
1-20. (canceled)
21. A system comprising a non-transitory computer readable medium
containing computer executable instructions for guiding an
interventional instrument, including instructions for: identifying
a target structure in an anatomic frame of reference; determining a
target region in the anatomic frame of reference with respect to a
current location of the interventional instrument wherein
determining the target region includes determining a probability of
a location of the target structure relative to the current location
of the interventional instrument; and recording a first engagement
location of the interventional instrument within the target
region.
22. The system of claim 21 wherein at least a portion of the target
structure is located within the target region.
23. The system of claim 21 wherein the anatomic frame of reference
is a three-dimensional anatomic frame of reference and wherein
identifying the target structure includes identifying a model
target structure in a three-dimensional model frame of reference
and registering the three-dimensional model frame of reference to
the three-dimensional anatomic frame of reference.
24. The system of claim 21 wherein determining the target region
includes at least one of determining a change in a patient
anatomical pose between a preoperative imaging time and an
interventional procedure time, determining an uncertainty value for
a sensor in the interventional instrument, determining an
uncertainty value associated with a shape of a target anatomic
structure, determining a value associated with a property of tissue
surrounding the target structure, and visualizing a target anatomic
structure with an imaging device.
25. The system of claim 21 wherein the interventional instrument
includes a catheter and a tool and determining the target region
includes determining an uncertainty value for a known
characteristic of the tool extended from the catheter.
26. The system of claim 21 further including instructions for
timing conduct of a first engagement procedure at the first
engagement location based on a cyclical anatomical motion
state.
27. The system of claim 21 further including instructions for
identifying a second engagement location for deploying the
interventional instrument.
28. The system of claim 27 further including instructions for
determining a revised target region in the anatomic frame of
reference based on information gathered from the first engagement
location.
29. The system of claim 28 wherein the second engagement location
is located within the revised target region.
30. The system of claim 21 further including instructions for
recording a second engagement location of the interventional
instrument within the target region.
31. The system of claim 30 further including instructions for
conducting a second engagement procedure at the second engagement
location based on information obtained from the first engagement
location.
32. The system of claim 30 further including instructions for
determining a first deployment location for the interventional
instrument prior to recording the first engagement location; and
determining a second deployment location for the interventional
instrument prior to recording the second engagement location,
wherein the first deployment location is different from the second
deployment location.
33. A system comprising: an interventional instrument including a
catheter and a tool deployable from the catheter; and a control
system configured to: identify a target structure in an anatomic
frame of reference; determine a target region in the anatomic frame
of reference with respect to a current location of the
interventional instrument, wherein determining the target region
includes determining a probability of a location of the target
structure relative to the current location of the interventional
instrument; and record a first engagement location of the
interventional instrument within the target region.
34. The system of claim 33 wherein the anatomic frame of reference
is a three-dimensional anatomic frame of reference and wherein
identifying the target structure includes identifying a model
target structure in a three-dimensional model frame of reference
and registering the three-dimensional model frame of reference to
the three-dimensional anatomic frame of reference.
35. The system of claim 33 wherein determining the target region
includes at least one of determining a change in a patient
anatomical pose between a preoperative imaging time and an
interventional procedure time, determining an anatomical motion
cycle, determining an uncertainty value for a characteristic of the
tool extended from the catheter, determining an uncertainty value
associated with a shape of a target anatomic structure, and
visualizing a target anatomic structure with an imaging device.
36. The system of claim 35 wherein the anatomical motion cycle is a
respiration cycle.
37. The system of claim 33 wherein the control system is further
configured to provide instructions for when to conduct a first
engagement procedure at the first engagement location based on a
cyclical anatomical motion state.
38. The system of claim 33 wherein the control system is configured
to: record a second engagement location of the interventional
instrument within the target region.
39. The system of claim 38 wherein the control system is further
configured to provide instructions for conducting a second
engagement procedure at a second engagement location based on
information obtained from the first engagement location.
40. The system of claim 33 wherein the control system is further
configured to generate a graphical user interface (GUI) including a
target marker representing the target structure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application 61/747,920 filed Dec. 31, 2012, which is incorporated
by reference herein in its entirety.
FIELD
[0002] The present disclosure is directed to systems and methods
for navigating a patient anatomy to conduct a minimally invasive
procedure, and more particularly to systems and methods for
planning a procedure to deploy an interventional instrument.
BACKGROUND
[0003] Minimally invasive medical techniques are intended to reduce
the amount of tissue that is damaged during interventional
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 interventional instruments
(including surgical, diagnostic, therapeutic, or biopsy
instruments) to reach a target tissue location. To reach the target
tissue location, a minimally invasive interventional instrument may
navigate natural or surgically created passageways in anatomical
systems such as the lungs, the colon, the intestines, the kidneys,
the heart, the circulatory system, or the like. To assist the
clinician in navigating the instrument through the passageways,
models of the passageway are prepared using pre-operative or
inter-operative imaging. Current systems for deploying an
interventional instrument identify an instrument deployment
location as the point within the modeled passageways closest to the
target tissue location. This closest-point deployment location may
be difficult to access given the constraints of the interventional
instrument or the anatomy. Improved systems and methods are needed
to determine a planned instrument deployment location for
conducting a procedure on the target tissue location.
SUMMARY
[0004] The embodiments of the invention are summarized by the
claims that follow the description.
[0005] In one embodiment, a method of deploying an interventional
instrument is performed by a processing system. The method
comprises receiving an image of an anatomic structure from an
imaging probe. The image has an image frame of reference. The
imaging probe is extendable distally beyond a distal end of a guide
catheter. The distal end of the guide catheter has a catheter frame
of reference. The method further includes receiving location data
associated with a target structure identified in the image. The
received location data is in the image frame of reference. The
method further comprises transforming the location data associated
with the target structure from the image frame of reference to the
catheter frame of reference.
[0006] In another embodiment, a system comprises non-transitory
computer readable media containing computer executable instructions
for planning a procedure to deploy an interventional instrument.
The instructions include instructions for receiving an image of an
anatomic structure from an imaging probe. The image has an image
frame of reference, wherein the imaging probe is extendable
distally beyond a distal end of a guide catheter, the distal end of
the guide catheter having a catheter frame of reference. The
instructions further include instructions for receiving location
data associated with a target structure identified in the image.
The received location data is in the image frame of reference. The
instructions further include instructions for transforming the
location data associated with the target structure from the image
frame of reference to the catheter frame of reference..
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0007] 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.
[0008] FIG. 1 is a teleoperated interventional system, in
accordance with embodiments of the present disclosure.
[0009] FIG. 2 illustrates an interventional instrument system
utilizing aspects of the present disclosure.
[0010] FIG. 3 illustrates a distal end of the interventional
instrument system of FIG. 2 with an extended interventional
tool.
[0011] FIG. 4 illustrates an anatomic model image with a distal end
of an interventional instrument at a deployment location.
[0012] FIG. 5 is a view of a portion of the FIG. 4.
[0013] FIG. 6 illustrates an anatomic model image with a distal end
of an interventional instrument at a revised deployment location
based on sensor feedback.
[0014] FIG. 7 is a flowchart describing a method for identifying a
planned deployment location for an interventional instrument.
[0015] FIG. 8 is a flowchart describing a method for revising the
planned deployment location based upon sensor feedback.
[0016] FIG. 9 is a flowchart describing a method for identifying
the target structuresing the imaging systems.
[0017] FIG. 10a illustrates an imaging system according to an
embodiment of the present disclosure.
[0018] FIG. 10b illustrates an image generated by the imaging
system of FIG. 10a.
[0019] FIG. 11 illustrates an alternative embodiment of an imaging
system according to an embodiment of the present disclosure.
[0020] FIG. 12 illustrates a biopsy procedure according to an
embodiment of the present disclosure.
[0021] FIGS. 13a and 13c illustrate cross-sectional views of an
ultrasound imaging probe according to another embodiment of the
present disclosure.
[0022] FIG. 13b illustrates an image from the ultrasound imaging
probe of FIGS. 13a and 13c.
DETAILED DESCRIPTION
[0023] In the following detailed description of the aspects of the
invention, numerous specific details are set forth in order to
provide a thorough understanding of the disclosed embodiments.
However, it will be obvious to one skilled in the art that the
embodiments of this disclosure may be practiced without these
specific details. In other instances well known methods,
procedures, components, and circuits have not been described in
detail so as not to unnecessarily obscure aspects of the
embodiments of the invention. And, to avoid needless descriptive
repetition, one or more components or actions described in
accordance with one illustrative embodiment can be used or omitted
as applicable from other illustrative embodiments.
[0024] The embodiments below will describe various instruments and
portions of instruments in terms of their state in
three-dimensional space. 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). 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). 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).
As used herein, the term "shape" refers to a set of poses,
positions, or orientations measured along an object.
[0025] Referring to FIG. 1 of the drawings, a teleoperated
interventional system for use in, for example, surgical,
diagnostic, therapeutic, or biopsy procedures, is generally
indicated by the reference numeral 100. As shown in. FIG. 1, the
teleoperated system 100 generally includes an interventional
manipulator assembly 102 for operating an interventional instrument
104 in performing various procedures on the patient P. The assembly
102 is mounted to or near an operating table O. A master assembly
106 allows the surgeon S to view the interventional site and to
control the slave manipulator assembly 102.
[0026] 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 assemblies 102. The control device(s) 112 may
include any number of a variety of input devices, such as
joysticks, trackballs, data gloves, trigger-guns, hand-operated
controllers, voice recognition devices, body motion or presence
sensors, or the like. In some embodiments, the control device(s)
112 will be provided with the same degrees of freedom as the
associated interventional instruments 104 to provide the surgeon
with telepresence, or the perception that the control device(s) 112
are integral with the instruments 104 so that the surgeon has a
strong sense of directly controlling instruments 104. In other
embodiments, the control device(s) 112 may have more or fewer
degrees of freedom than the associated interventional instruments
104 and still provide the surgeon with telepresence. In some
embodiments, the control device(s) 112 are manual input devices
which move 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).
[0027] In alternative embodiments, the teleoperated system may
include more than one slave manipulator assembly and/or more than
one master assembly. The exact number of manipulator assemblies
will depend on the interventional procedure and the space
constraints within the operating room, among other factors. The
master assemblies may be collocated, or they may be positioned in
separate locations. Multiple master assemblies allow more than one
operator to control one or more slave manipulator assemblies in
various combinations.
[0028] An optional visualization system 110 may include an
endoscope system such that a concurrent (real-time) image of the
interventional site is provided to surgeon console C. The
concurrent image may be, for example, a two- or three-dimensional
image captured by an endoscopic probe positioned within the
interventional site. In this embodiment, the visualization system
110 includes endoscopic components that may be integrally or
removably coupled to the interventional instrument 104. In
alternative embodiments, however, a separate endoscope attached to
a separate manipulator assembly may be used to image the
interventional site. Alternatively, a separate endoscope assembly
may be directly operated by a user, without teleoperational
control. The endoscope assembly may include active steering (e.g.,
via teleoperated steering wires) or passive steering (e.g., via
guide wires or direct user guidance). The visualization system 110
may be implemented as hardware, firmware, software, or a
combination thereof, which interacts with or is otherwise executed
by one or more computer processors, which may include the
processor(s) of a control system 116.
[0029] A display system 111 may display an image of the
interventional site and interventional instruments captured by the
visualization system 110. The display 111 and the master control
device(s) 112 may be oriented such that the relative positions of
the imaging device in the scope assembly and the interventional
instruments are similar to the relative positions of the surgeon's
eyes and hand(s) so the operator can manipulate the interventional
instrument 104 and the master control device(s) 112 as if viewing
the workspace in substantially true presence. True presence means
that the displayed tissue image appears to an operator as if the
operator was physically present at the imager location and directly
viewing the tissue from the imager's perspective.
[0030] Alternatively or additionally, display system 111 may
present images of the interventional 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),
diffuse optical tomography (DOT), thermal imaging, impedance
imaging, laser imaging, nanotube X-ray imaging, or the like. The
presented preoperative images may include two-dimensional,
three-dimensional, or four-dimensional (including e.g., time based
or velocity based information) images.
[0031] In some embodiments, the display system 111 may display a
virtual visualization image in which the actual location of the
interventional instrument is registered (e.g., dynamically
referenced) with preoperative or concurrent images from the modeled
anatomy to present the surgeon S with a virtual image of the
internal interventional site at the location of the tip of the
interventional instrument.
[0032] In other embodiments, the display system 111 may display a
virtual visualization image in which the actual location of the
interventional instrument is registered with prior images
(including preoperatively recorded images) or concurrent images
from the modeled anatomy to present the surgeon S with a virtual
image of an interventional instrument at the interventional site.
An image of a portion of the interventional instrument may be
superimposed on the virtual image to assist the surgeon controlling
the interventional instrument.
[0033] 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 slave surgical manipulator assembly
102, the master assembly 106, the visualization system 110, and the
display system 111. The control system 116 also includes programmed
instructions (e.g., a computer-readable medium storing the
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 system may comprise a number of
data processing circuits (e.g., on the slave surgical manipulator
assembly 102 and/or on the master assembly 106), with at least a
portion of the processing optionally being performed adjacent the
slave surgical manipulator assembly, a portion being performed at
the master assembly, and the like. Any of a wide variety of
centralized or distributed data processing architectures may be
employed. Similarly, the programmed instructions may be implemented
as a number of separate programs or subroutines, or they may be
integrated into a number of other aspects of the teleoperational
systems described herein. In one embodiment, control system 116
supports wireless communication protocols such as Bluetooth, IrDA,
HomeRF, IEEE 802.11, DECT, and Wireless Telemetry.
[0034] In some embodiments, control system 116 may include one or
more servo controllers to provide force and torque feedback from
the interventional instruments 104 to one or more corresponding
servomotors for the control device(s) 112. The servo controller(s)
may also transmit signals instructing manipulator assembly 102 to
move instruments which extend into an internal surgical site within
the patient body via openings in the body. Any suitable
conventional or specialized servo controller may be used. A servo
controller may be separate from, or integrated with, manipulator
assembly 102. In some embodiments, the servo controller and
manipulator assembly are provided as part of a manipulator arm cart
positioned adjacent to the patient's body.
[0035] Each manipulator assembly 102 supports a interventional
instrument 104 and may comprise a kinematic structure of one or
more non-servo controlled links (e.g., one or more links that may
be manually positioned and locked in place, generally referred to
as a set-up structure) and a teleoperated manipulator. The
teleoperated manipulator assembly 102 is driven by a plurality of
actuators (e.g., motors). These motors actively move the
teleoperated manipulators in response to commands from the control
system 116. The motors are further coupled to the interventional
instrument so as to advance the interventional instrument into a
naturally or surgically created anatomical orifice and to move the
distal end of the interventional instrument in multiple degrees of
freedom, which may include three degrees of linear motion (e.g.,
linear motion along the X, Y, Z Cartesian axes) and three degrees
of rotational motion (e.g., rotation about the X, Y, Z Cartesian
axes). Additionally, the motors can be used to actuate an
articulable end effector of the instrument for grasping tissue in
the jaws of a biopsy device or the like.
[0036] FIG. 2 illustrates a minimally invasive system 200 utilizing
aspects of the present disclosure. The system 200 may be
incorporated into a teleoperated interventional system, such as
system 100. Alternatively, the system 200 may be used for
exploratory procedures or in procedures involving traditional
manually operated interventional instruments, such as laparoscopic
instruments. The system 200 includes a catheter system 202 (e.g.,
part of the instrument 104) coupled by an interface unit 204 to a
tracking system 206. A navigation system 210 (e.g., part of the
control system 116) processes information from a virtual
visualization system 208, one or more imaging systems 212, and/or
the tracking system 206 to generate one or more image displays on a
display system 214 (e.g., part of the display system 111). The
system 200 may further include optional operation and support
systems (not shown) such as illumination systems, steering control
systems, irrigation systems, and/or suction systems.
[0037] The catheter system 202 includes an elongated flexible body
216 having a proximal end 217 and a distal end 218. A channel 219
extends within the flexible body 216. In one embodiment, the
flexible body 216 has an approximately 3 mm outer diameter. Other
flexible body outer diameters may be larger or smaller. The
catheter system 202 optionally includes a sensor system which
includes a position sensor system 220 (e.g., an electromagnetic
(EM) sensor system) and/or a shape sensor system 222 for
determining the position, orientation, speed, pose, and/or shape of
the catheter tip at distal end 218 and/or of one or more segments
224 along the body 216. The entire length of the body 216, between
the distal end 218 and the proximal end 217 may be effectively
divided into the segments 224. The position sensor system 220 and
the shape sensor system 222 interface with the tracking system 206.
The tracking system 206 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.
[0038] The position sensor system 220 may be an EM sensor system
that includes one or more conductive coils that may be subjected to
an externally generated electromagnetic field. Each coil of the EM
sensor system 220 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 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.
[0039] The shape sensor system 222 includes an optical fiber
aligned with the flexible body 216 (e.g., provided within an
interior channel (not shown) or mounted externally). The tracking
system 206 may be coupled to a proximal end of the optical fiber.
In one embodiment, the optical fiber has a diameter of
approximately 200 .mu.m. In other embodiments, the dimensions may
be larger or smaller. Alternatively, external imaging of the
anatomy containing the catheter can be used to reconstruct the
shape of the catheter.
[0040] The optical fiber of the shape sensor system 222 forms a
fiber optic bend sensor for determining the shape of the catheter
system 202. 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, disclosing "Fiber optic
position and shape sensing device and method relating thereto;"
U.S. Provisional Pat. App. No. 60/588,336, filed on Jul. 16, 2004,
disclosing "Fiber-optic shape and relative position sensing;" 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 catheter may be determined using
other techniques. For example, if the history of the catheter's
distal tip 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 device over the
interval of time. As another example, historical pose, position, or
orientation data may be stored for a known point of an instrument
along a cycle of alternating motion, such as breathing. This stored
data may be used to develop shape information about the catheter.
Alternatively, a series of positional sensors, such as EM sensors,
positioned along the catheter can be used for shape sensing.
Alternatively, a history of data from a positional sensor, such as
an EM sensor, on the instrument during a procedure may be used to
represent the shape of the instrument, 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.
[0041] In this embodiment, the optical fiber 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.
[0042] In some embodiments, an array of FBG's 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 FBG's, 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.
[0043] Thus, to measure strain, light is sent down the fiber, and
characteristics of the returning light are measured. For example,
FBG's 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 teleoperational 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.
[0044] 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 FBG's, 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.
[0045] As described, the optical fiber may be used to monitor the
shape of at least a portion of the catheter system 202. More
specifically, light passing through the optical fiber is processed
by the tracking system 206 for detecting the shape of the catheter
system 202 and for utilizing that information to assist in
interventional procedures. The tracking system 206 may include a
detection system for generating and detecting the light used for
determining the shape of the catheter system 202. This information,
in turn, can be used to determine other related variables, such as
velocity and acceleration of the parts of an interventional
instrument. The sensing may be limited only to the degrees of
freedom that are actuated by the teleoperational system, or may be
applied to both passive unactuated bending of the rigid members
between joints) and active (e.g., actuated movement of the
instrument) degrees of freedom.
[0046] The flexible body 216 may optionally house one or more image
capture probes 226 that transmit captured image data to the imaging
system(s) 212. For example, the image capture probe 226 may be an
endoscopic probe including a tip portion with a stereoscopic or
monoscopic camera disposed near the distal end 218 of the flexible
body 216 for capturing images (including video images) that are
transmitted to the imaging system 212. The image capture probe 226
may include a cable coupled to the camera for transmitting the
captured image data. Alternatively, the image capture instrument
may be a fiber-optic bundle, such as a fiberscope, that couples to
the imaging system. The image capture instrument may be single or
multi-spectral, for example capturing image data in the visible
spectrum, or capturing image data in the visible and infrared or
ultraviolet spectrums.
[0047] Additionally or alternatively, the image capture probe 226
may be a sensor probe for use with a imaging technology such as
ultrasound, OCT, or DOT. For example, the probe may include a
transmitter and receiver arrangement, such as an ultrasound
transducer. The ultrasonic transducer can be mounted at an end of
an elongated shaft. Such a source can be used to obtain a
preoperative or intraoperative two-dimensional or three-dimensional
image, or model, of the anatomic region where the interventional
procedure is to be performed. As a two-dimensional source, the
ultrasonic transducer can be used to obtain a single ultrasound
image. As a three-dimensional source it can be used to obtain a
plurality of spaced ultrasonic images, or cuts, thereby to provide
sufficient information for construction of a three-dimensional
model. Accordingly, it can be arranged to move, including rotate,
within an anatomic site to capture such images, or cuts. This can
typically be achieved, for example, in accordance with a
pre-programmed sequence for moving the ultrasound transducer by
teleoperational control, manual movement of the ultrasound
transducer, or the like.
[0048] The body 216 may also house cables, linkages, or other
steering controls (not shown) that extend between the interface 204
and the tip distal end 218 to controllably bend or turn the distal
end 218 as shown for example by the dotted line versions of the
distal end. The catheter system may be steerable or, alternatively,
may be non-steerable with no integrated mechanism for operator
control of the instrument bending. The flexible body 216 may
further house control mechanisms (not shown) for operating a
surgical end effector or another 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,
an optical fiber, or an electrode. Other end effectors may include
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.
[0049] As shown in greater detail in FIG. 3, interventional tool(s)
228 for such procedures as surgery, biopsy, ablation, illumination,
irrigation, or suction can be deployed through the channel 219 of
the flexible body 216 and used at a target location within the
anatomy. The intervertebral tool 228 may also be the image capture
probe. The tool 228 may be advanced from the opening of the channel
219 to perform the procedure and then retracted back into the
channel when the procedure is complete. The interventional tool 228
may be removed from the proximal end 217 of the catheter flexible
body or from another optional instrument port (not shown) along the
flexible body.
[0050] The virtual visualization system 208 provides navigation
assistance to the catheter system 202. Virtual navigation using the
virtual visualization system is based upon reference to an acquired
dataset associated with the three dimensional structure of the
anatomical passageways. More specifically, the virtual
visualization system 208 processes images of the interventional
site recorded and/or modeled using imaging technology such as
computerized tomography (CT), magnetic resonance imaging (MRI),
fluoroscopy, thermography, ultrasound, OCT, DOT, thermal imaging,
impedance imaging, laser imaging, nanotube X-ray imaging, or the
like. Software is used to convert the recorded images into a two
dimensional or three dimensional model of a partial or an entire
anatomical organ or anatomical region. The model describes the
various locations and shapes of the passageways and their
connectivity. The images used to generate the model may be recorded
preoperatively or intra-operatively during a clinical procedure. In
an alternative embodiment, a virtual visualization system may use
standard models (i.e., not patient specific) or hybrids of a
standard model and patient specific data. The model and any virtual
images generated by the model may represent the static posture of a
deformable anatomic region during one or more phases of motion
(e.g., during an inspiration/expiration cycle of a lung).
[0051] During a virtual navigation procedure, the sensor systems
may be used to compute an approximate location of the instrument
with respect to the patient anatomy. The location can be used to
produce both macro-level tracking images of the patient anatomy and
virtual internal images of the patient anatomy. Various systems for
using fiber optic sensors to register and display an interventional
implement together with preoperatively recorded surgical images,
such as those from a virtual visualization system, are known. For
example 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, discloses one
such system.
[0052] The navigation system 210, as part of the control system
116, processes information from the virtual visualization system
208, the one or more imaging systems 212, and/or the tracking
system 206 to determine a navigational path for the interventional
instrument through the anatomical system to the target anatomical
structure. The navigation system 210 may also monitor the
navigational path of the interventional instrument as it moves
through the anatomical system to a target structure. The navigation
system 210 includes a planning module 211 that allows a clinician
to locate a target anatomical structure (e.g., a tumor) in the
anatomical model prepared by the virtual visualization system 208
and to identify a navigational path through anatomical passageways
to reach the target structure to perform an interventional
procedure (e.g., a biopsy) with the interventional instrument. The
target localization and navigational path determination may be
automated such that the navigation system identifies one or more
navigational paths. Alternatively, a clinician may determine the
navigational path from the anatomic model and optionally
communicate the selected path to the navigational system. In still
another alternative, the planning module uses a hybrid automated/
clinician selected navigational path determination in which the
clinician may modify a system planned path or in which the
clinician may enter parameters such as anatomical areas to avoid or
instrument limitations that constrain the planned navigational path
suggested by the planning module 212.
[0053] The navigation planning module generates or allows the
clinician to select a planned deployment location within an
anatomical passageway for parking a distal end of the
interventional instrument to conduct the interventional procedure.
Referring now to FIG. 4, a virtual image 300 of target structure
302, such as a tumor, and nearby anatomic passageways 304 is
depicted. The passageways include passageway walls 306 and carina
308. In this embodiment, the anatomic passageways are bronchial
passageway's of the lung, but the systems and methods of this
disclosure may be suitable for use in other natural or surgically
created passageway's in anatomical systems such as the colon, the
intestines, the kidneys, the heart, or the circulatory system. An
interventional instrument with a flexible body 309 (substantially
similar to flexible body 216) and an extended interventional tool
310 are shown. In one embodiment, a navigation planning module
identifies the planned deployment location as a location 312 along
a wall of an anatomic passageway closest to or nearby to the target
structure. However, selecting the deployment location entirely on
the basis of proximity to the target structure may result in a
selected deployment location that is inaccessible or not easily
accessible by the interventional instrument. For example, the
interventional instrument may be incapable of bending sufficiently
within the passageway to access the proximity based deployment
location. Additionally the selected deployment location or the
navigational path to the deployment location may not consider
anatomical constraints, such as scar or diseased tissue to avoid.
As another example, a deployment location can be selected to
minimize the amount of tissue deformation and thus the risk of
tissue damage.
[0054] In other embodiments, a navigation planning module selects
the deployment location based upon a plurality of factors, which in
some instances may be procedural characteristics, such as the
distance to the target structure, and/or the position of the target
structure relative to other anatomic features. In other
embodiments, the navigation planning module may additionally or
alternatively receive and use information about the operational
capability of the interventional instrument to determine a
deployment location. For example, information pertaining to the
bending capability of the instrument may be considered, such as the
flexibility and elasticity of the catheter material, any preformed
shape characteristics of the catheter or tools passed through the
channel of the catheter, the steerability of the distal end of the
catheter or tool (e.g., the degree to which the distal tip of the
catheter may be curved relative to the main axis of the catheter),
and the curvature along the length of the catheter. Other
characteristics of the interventional instrument may also be used
to determine the deployment location including the diameter of the
catheter, the diameter of the tool, the trajectory of the tool when
extended from the catheter (e.g., curved, straight), the movement
of the tool (e.g., sweeping, spinning, linear), the maximum
angulation of the axis of the tool versus the axis of the catheter,
the maximum length the tool can be extended from the catheter, and
any anchoring structures at the distal tip of the catheter
providing frictional contact with the passageway wall. The
information pertaining to the bending capability and/or the
information related to the characteristics of the interventional
instrument are exemplary factors that can be used to determine the
operational capability of the interventional instrument within the
anatomical passageways.
[0055] The navigation planning module may also or alternatively
receive and use information about the patient anatomy to determine
a deployment location. Such information may include, for example,
the location of the carinal of the anatomical passageways nearest
to the target structure and the size of the passageways nearest to
the target structure. Other anatomic information may include the
elasticity of the anatomical passageways including the impact that
any disease processes may have had on the elasticity of the
passageways. The navigation planning model may also consider the
surrounding anatomic tissue to, for example, select a deployment
location that reduces the risk to surrounding tissue. As one
example, a deployment location away from the perimeter of a lung
may be selected to avoid the risk of puncturing the lung with the
deployed tool. The navigation planning model may also consider the
anatomy of the target structure to access a preferred location of
the target structure. For example, the deployment location may be
selected such that a biopsy tool avoids a calcified part of a
tumor. If the shape of the target is not round, the deployment
location can be selected to maximize the probability of hitting the
target considering the navigation uncertainty and the shape of the
target.
[0056] The navigation planning module may also consider information
about the relationship between the interventional instrument and
the patient anatomy such as the distance of the target structure
from the end of the catheter. Referring to FIG. 5, the navigation
planning module may also consider the angle of approach 320 between
the interventional tool and the passageway wall. For example, an
approach angle of 90.degree. may impracticable due to the small
size of the passageway and the bendability of the distal tip of the
catheter. An approach angle of 1.degree. may also be unsuitable
because of the risk that the interventional tool may graze the
surface of the passageway wall without penetrating. For these
reasons, the navigation planning module may select a deployment
location such that the approach angle is between approximately
30.degree. and 90.degree..
[0057] Referring again to FIG. 4, after the navigation planning
module evaluates the factors related to the interventional
instrument and the patient anatomy, a deployment location 314 on
the wall of an anatomic passageway is identified. Optionally, the
navigation planning module may provide a suggested navigational
path to the deployment location. The clinician can then direct the
distal end of the interventional instrument to the deployment
location. The clinician may manually control the navigation of the
interventional instrument based upon virtual or real image
guidance. Alternatively, the clinician can teleoperationally
control the navigation of the interventional instrument, or allow
computer-controlled navigation of the interventional instrument
along the suggested navigational path. After the distal end of the
interventional instrument is positioned at the deployment location,
the interventional tool is extended from the catheter, through the
passageway wall and into contact with the target structure. In some
circumstances, for example when a target structure is located
within an anatomic passageway, the deployment location may be
located within the lumen of the passageway, rather than on the wall
of the passageway. For example when the target structure is within
the passageway, the deployment location may be on a surface of the
target structure.
[0058] FIG. 7 is a flowchart describing a method 400 used by the
navigation planning module for identifying a planned deployment
location for an interventional instrument. At 402, a model of an
anatomic structure is received. The anatomic structure includes a
plurality of anatomic passageways which are illustrated by the
model. The model is formed from two or three dimensional images of
the interventional site recorded and/or modeled preoperatively or
interoperatively using imaging technology such as CT, MRI,
fluoroscopy, thermography, ultrasound, OCT, thermal imaging,
impedance imaging, laser imaging, nanotube X-ray imaging, or the
like. Receipt of the model may include receiving information about
the patient anatomy derived from the model, from user inputs
describing the patient anatomy, or from other reference sources.
Such information about the patient anatomy may include, for
example, the closest location(s) within an anatomic passageway(s)
to the target structure, the location of the carinas of the
anatomical passageways nearest to the target structure, and the
size of the passageways nearest to the target structure. Other
anatomic information may include the elasticity of the anatomical
passageways, the anatomy of the target structure to access a
preferred location of the target structure, and the type of
surrounding tissue and any risk associated with contacting the
surrounding tissue.
[0059] At 404, a location of a target structure (e.g., a tumor) is
identified in the model. Identifying the target structure may
include determining or receiving information about the target
structure from the model, from user inputs describing the target
structure, or from other reference sources. Such information about
the target structure may include, for example, the shape of the
target structure, the one or more substances that form the target
structure, and the location of the surfaces of the target structure
relative to nearby anatomic passageway's.
[0060] At 406, information about the operational capability of the
interventional instrument is received. The information received to
determine the operational capability of the interventional
instrument may include, for example, information pertaining to the
bending capability of the instrument such as the flexibility and
elasticity of the catheter material, any preformed shape
characteristics of the catheter or tools passed through the channel
of the catheter, the steerability of the distal end of the catheter
or tool, and the curvature along the length of the catheter. The
operational capability of the interventional instrument may also be
determined from characteristics of the interventional instrument
such as the diameter of the catheter, the diameter of the tool, the
maximum angulation of the axis of the tool versus the axis of the
catheter, the maximum length the tool can be extended from the
catheter, and any anchoring structures at the distal tip of the
catheter providing frictional contact with the passageway wall.
[0061] At 408, a planned deployment location for the interventional
instrument is located. The planned deployment location may be
marked on the model of the plurality of passageways. The planned
deployment location can be selected based upon the instrument
operational capability information, the target structure
information, the patient anatomy information, or a combination of
the types of information. The selected deployment location may be
at a point in an anatomic passageway nearest to the target
structure. However, in many patients a nearest point deployment
location may be impossible for the distal end of the interventional
instrument to reach because the instrument has insufficient bend
capability within the size and elasticity constraints of the
selected anatomic passageway. A more suitable deployment location
may be at a point on an anatomic passageway wall where the
interventional instrument has an approach angle to the passageway
wall that is within the bending capability of the instrument. For
example, if the interventional instrument has an inflexible distal
end that permits little or no bending, a suitable deployment
location may be at a carina near the target structure. At the
carina the interventional instrument may be deployed at an
approximately 90.degree. approach angle to the passageway wail with
minimal bending of the distal end of the instrument. As another
example, the navigation planning module may select a deployment
location such that the approach angle is between approximately
30.degree. and 90.degree.. When selecting a deployment location,
the planning system also confirms that the interventional tool is
capable of extending from the catheter a sufficient distance to
reach the target structure to perform the interventional
procedure.
[0062] As described, the planned deployment location may be located
based on the analysis of the instrument operational capability, the
target structure, and the patient anatomy. Alternatively or in
combination with the system assessment, the planned deployment
location may be identified by a clinician and communicated to the
navigation planning module to locate or mark the
clinician-identified planned deployment location in the model. When
the navigation planning module receives the clinician-identified
planned deployment location, the module may compare it with the
system-identified deployment location. A visual or audible feedback
cue may be issued if the clinician-identified deployment location
is objectionable (e.g., "The chosen biopsy needle is not long
enough to reach the target from this deployment location.").
[0063] Optionally, the navigation planning module identifies
multiple elective deployment locations. The elective deployment
locations may be coded (e.g., with color on the display) to provide
information about the relative quality of the elective deployment
locations for deploying the interventional instrument to perform
the procedure. A clinician may select one of elective deployment
locations to be the planned deployment location. Alternatively,
more than one planned deployment location may be selected from the
elective deployment locations, allowing the interventional
procedure to be performed from different approaches. The selection
of elective deployment locations may also occur during the
interventional procedure if the clinician determines that an
initially chosen deployment location is unsuitable.
[0064] To further refine the step of identifying the target
structure, one or more of the imaging systems 212 may be used to
gather additional information about the location of the target
structure after the interventional instrument has been deployed to
the identified deployment location or the general vicinity thereof.
Referring now to FIG. 6, the virtual image 300 of target structure
302 and nearby anatomic passageways 304 is again depicted. The
distal end of the flexible body 309 is first positioned at a target
confirmation location such as location 312. The image capture probe
226 is operated to determine if the target structure 302 is in the
expected position relative to the target confirmation location. If
the target structure 302 is not found or not in the expected
position, the flexible body and image capture probe can be moved
around until the target structure is located. When the target
structure is located, the location of the distal end of the
flexible body 309 or image capture probe is recorded at a new
location 322. The navigation planning module 211 then updates the
location of the target structure 302'. With the new location of the
target structure identified, the operational capability information
for the interventional instrument is used to identify a revised
planned deployment location 324. For example, the navigation
planning module may use the difference between locations 312 and
322 to update location 314 to location 322 and to update the
location of the target structure 302 to 302'. In one embodiment,
the image capture probe uses one or more sensors for reflective
imaging technology such as ultrasound or OCT to refine the location
of the target structure. Alternatively, other non-imaging sensors
may be used to identify the location of the target structure.
[0065] FIG. 8 is a flowchart describing a method 450 used by the
navigation planning module for revising a planned deployment
location for an interventional instrument. At 452, information is
received from the image capture probe after the probe has been
operated at the initial planned deployment location or at a target
confirmation location. At 454, a revised location of the target
structure is identified using the information received from the
image capture probe. At 456, a revised planned deployment location
is identified in the model of the plurality of passageways.
[0066] The confirmation of the location of the target structure
and/or the identification of a revised location of the target
structure may be performed using an ultrasound system. The use of
ultrasound technology for confirmation and revision of the target
structure location may allow for greater accuracy in biopsy or
other focal therapies directed to nodules with small diameters
(e.g., approximately 10 mm or smaller) FIG. 10a illustrates a
virtual image 600 of a target structure P.sub.M, such as a tumor,
and nearby anatomic passageway's 602. The passageways include
passageway walls 604. The passageways 602 are located in a patient
frame of reference with coordinate system (X.sub.P, Y.sub.P,
Z.sub.P). The patient reference frame is a fixed reference frame
(i.e., one that does not move during the medical procedure). The
image of the plurality of passageways 602 (e.g. obtained from pre-
or intra-operative modeling) may be registered to the fixed
reference frame. The location of the target structure P.sub.M is
determined from pre-operative or intra-operative imaging, as
previously described, and is transformed to the patient frame of
reference. In this embodiment, the anatomic passageways are
bronchial passageways of the lung, but the systems and methods of
this disclosure may be suitable for use in other natural or
surgically created passageways in anatomical systems such as the
colon, the intestines, the kidneys, the heart, or the circulatory
system. As previously described, a flexible catheter body 608
(substantially similar to flexible body 216) may be navigated to a
catheter park location that allows access to a target structure.
The catheter may be navigated using, for example, visual endoscopy,
EM sensors, and/or optical fiber shape-based navigation techniques.
An imaging probe 606 is inserted through the flexible catheter body
608. In one embodiment, the imaging probe is an ultrasound probe.
The ultrasound probe may be a side-imaging probe including a
rotating ultrasound transducer for imaging in a direction generally
perpendicular to the axis of rotation of the transducer. The
side-imaging probe generates a cross-sectional (i.e., radial) image
along an imaging plane 612. A suitable ultrasound probe may be an
ultrasonic bronchoscope available from Olympus America, Inc. of
Center Valley, Pa. Optionally the ultrasound probe may be integral
with the catheter rather than interchangeable as shown in FIG. 10a.
In the embodiment of FIG. 10a, the axis of rotation of the
transducer is generally along the Z.sub.C direction. A side-imaging
probe generates images of the tissue at a radial distance from the
axis of rotation, including tissue located outside of the anatomic
passageways. In other embodiments, a forward-looking ultrasound
probe may be used to image tissue distal of the imaging transducer.
The ultrasound probe may be relatively small to navigate narrow
anatomical passageways. For example, the ultrasound probe may have
distal end diameter of approximately 1.4 mm.
[0067] The movement of the probe 606 relative to a distal end
portion 610 of the catheter 608 (e.g., the catheter tip) may be
tracked. A catheter frame of reference and coordinate system
(X.sub.C, Y.sub.C, Z.sub.C) is defined at the distal end portion
610 of the catheter 608 and is registered with the patient
coordinate system. The position and orientation of the distal end
portion 610 may be tracked, as described above, using sensor
systems (e.g., position sensor system 220 and/or the shape sensor
system 222) interfaced with a tracking system (e.g., tracking
system 206). As the probe 606 is extended from the catheter 608,
the position and orientation of the probe may be tracked in the
catheter frame of reference and/or in the patient frame of
reference. For example, the position and orientation of the probe
606 may be tracked using a positional sensor such as a 5 or 6
degree of freedom EM sensor located on the probe. Alternatively,
the movement may be tracked using an insertion sensor such as an
encoder located outside the patient anatomy. For example, an
encoder associated with a motor that drives the insertion of the
probe may be used to determine the insertion length. Alternatively,
the movement may be tracked by engaging a stepping motor to control
the insertion motion of the imaging probe. A tracked insertion
length L is determined between the distal end portion 610 of the
catheter and the imaging plane 612 of the probe (e.g., the image
plane of the side-imaging ultrasound transducer)
[0068] FIG. 10b illustrates an image 650 generated by the
ultrasound probe 606 in the imaging plane 612 shown in FIG. 10a.
The image 650 has an image frame of reference and coordinate system
(X.sub.I, Y.sub.I, Z.sub.I). The target structure P.sub.I is
identified in the image frame of reference. It may be identified,
for example, by a clinician, by an image analysis algorithm, or by
a combination of the two. The ultrasound scan may be gated for
respiratory and/or cardiac cycles. Although the image 650 is
two-dimensional, a three-dimensional image may be constructed from
a plurality of two-dimensional ultrasound scans. Data associated
with the location of the target structure P.sub.I in the image
frame of reference is transformed to the catheter coordinate system
or the patient coordinate system (that has been registered with the
catheter coordinate system) as P.sub.P. The location of the target
structure P.sub.P as determined by the ultrasound probe may be
compared to the location of the target structure P.sub.M determined
from pre-operative or intra-operative imaging in the catheter or
patient frame of reference to determine a correction vector 614.
The correction vector 614 is the offset value between the location
of the target structure P.sub.M and the location of the target
structure P.sub.P.
[0069] To transform the image coordinate system to the catheter
coordinate system, the relative three-dimensional pose between the
image coordinate system and the catheter coordinate system is
determined. It can be measured directly by sensors on the catheter
and imaging probe. Such sensors may include an EM sensor, a fiber
optic shape sensor, or the like. The sensors on the catheter and
the imaging probe do not need to be of the same type. The relative
three-dimensional pose may also be determined by two or more images
of the catheter using, for example, fluoroscopy. In case the full
three-dimensional pose is not directly measured, the same
information can be computed by measuring the insertion length L and
a known roll angle of the image coordinate system with respect to
the catheter coordinate system, assuming the imaging probe extends
straight beyond the tip of the catheter and the pose of the
catheter end is known. The insertion length L may be determined
using, for example, an encoder, a stepping motor, or external
imaging (e.g., fluoroscopy). The roll angle may be determined using
a variety of techniques. In one embodiment, as shown in FIG. 11, an
ultrasound probe 606' includes a roll alignment feature 615 keyed
to the catheter 608'. The roll alignment feature 615 causes the
probe 606 to maintain a fixed orientation about the catheter roll
axis (Zc) extending through the catheter. The roll alignment
feature allows the roll angle of the image reference frame of
reference and coordinate system (X.sub.I, Y.sub.I, Z.sub.I) to be
registered with respect to the catheter reference frame and
coordinate system (X.sub.C, Y.sub.C, Z.sub.C). In this embodiment,
the roll alignment feature is a shaped protrusion keyed to match a
similarly shaped channel in the catheter. In alternative
embodiments, the roll alignment feature may be a channel shaped to
match a protrusion in the catheter. More than one roll alignment
feature may be used to maintain the probe in a fixed orientation
about the catheter roll axis. In various other embodiments, the
roll angle of the image coordinate system with respect to the
catheter coordinate system may be determined by a roll sensor
located outside of the patient anatomy may be used. In still
another alternative, the roll angle may be determined by viewing
one or more markers or other features with a known angle relative
to the catheter in the image recorded by the imaging probe. For
example, the feature or marker may be located on the circumference
of the catheter and have a contrast (e.g. an ultrasound contrast)
to the catheter. In another alternative, the combined roll and
insertion length may be determined by observing a pattern on the
probe around the proximal end of the catheter or by observing a
pattern on the catheter around the proximal end of the probe.
[0070] After the ultrasound probe 606 is removed from the catheter
608 and replaced with a biopsy instrument 662. As shown in FIG. 12,
the catheter 608 may be steered to a revised position and/or
orientation that provides access to the revised target location
P.sub.P. The steering of the catheter may be accomplished directly
by active steering control of the catheter or indirectly by
navigating a steerable biopsy instrument 662. The biopsy instrument
662 is extended from the catheter 608, through the wall 604 of the
anatomic passageway 602 and into contact with the tumor structure
located at revised target location P.sub.P.
[0071] A method 500 for identifying the target structure using the
ultrasound probe 606 is described at FIG. 9. The method 500 may be
performed to identify an initial interventional deployment location
or may be used to identify a revised deployment location as
described below.
[0072] At 502, the catheter 608 is navigated to a passageway
location (e.g., location 312 or 314) with the guidance of the
navigation system including, for example, visual, EM or shape
sensor information. A confirmation from the clinician or from the
interventional instrument may be provided when the catheter has
reached the location. At 504, the probe 606 is inserted through the
catheter 608 and the movement (i.e. insertion length) of the probe
relative to the distal end portion 610 of the catheter is tracked.
In some embodiments, the same probe 606 may also be used in
performing the navigation to the passageway location at step 502.
The movement of the probe 606 may be tracked, for example using a
positional sensor such as a 5 or 6 degree of freedom EM sensor.
Alternatively, the movement may be tracked using an insertion
sensor such as an encoder located outside the patient anatomy,
Alternatively, the movement may be tracked by engaging a stepping
motor to control the insertion motion of the imaging probe.
[0073] At 506, a roll angle of the image coordinate system
(X.sub.I, Y.sub.I, Z.sub.I) is determined with respect to the
catheter frame of reference and coordinate system (X.sub.C,
Y.sub.C, Z.sub.C). For example, the roll angle may be determined
using the roll alignment feature of the imaging probe and the
catheter. Alternatively, a roll sensor located outside of the
patient anatomy may be used. In still another alternative, the roll
angle may be determined by viewing one or more markers or other
features with a known angle relative to the catheter in the image
recorded by the imaging probe. For example, the feature or marker
may be located on the circumference of the catheter and have a
contrast (e.g. an ultrasound contrast) to the catheter.
Alternatively, the roll angle and the insertion length of the
imaging probe with respect to the catheter may be measured by an
optical sensor (e.g., a camera) that is fixed to the catheter
observing a visual pattern placed around the imaging probe. The
visual pattern may contain features that uniquely determine
two-dimensional locations. Examples of such patterns may be found
in U.S. Pat. No. 8,223,193, filed Mar. 30, 2009, disclosing
"Targets, Fixtures, and Workflows for Calibrating an Endoscopic
Camera," which is incorporated by reference herein in its
entirety.
[0074] In an alternative embodiment as shown in FIGS. 13a-c, a
mechanically rotating radial ultrasound probe assembly 700 provides
an indicator to reference roll angle. Assembly 700 includes a
catheter 702 through which extends an ultrasound probe 704
surrounded at least in part by a sheath 706. The sheath 706 is
rotatably fixed (e.g. may be keyed) relative to the catheter 702.
An ultrasound opaque marker 708 is located on the sheath 706 within
an area through which the acoustic energy from the transducer 710
of ultrasound probe 704 passes to create an image plane 712. In
this embodiment, the sheath 706 that is transparent to ultrasound
except for the marker 708 on a circumferential area of the sheath
cross-section. The marker section that blocks ultrasound creates an
identifiable contrast region 714 in the ultrasound image 716 so
that it can he used as a reference roll angle. The body of the
sheath 706 can be constructed using a material that has acoustic
impedance that matches the ultrasound probe and the tissue so that
the acoustic energy can pass the sheath with little loss. The
alignment mark 708 may be constructed using a material that has
significantly different acoustic impedance to that of the
ultrasound probe and the tissue so that it reflects most of the
reflective energy to the transducer 710.
[0075] In various other embodiments, the ultrasound probe
(particularly the tip where the transducer is located) may be
tracked because the ultrasound probe may not extend distally
straight from the catheter. For example, a fiber optic shape sensor
(as described above) may be used to track the location of the
ultrasound probe tip. The shape sensor may be incorporated into the
ultrasound probe or into a sheath surrounding the probe.
Additionally or alternatively, one or more fluoroscopy images may
be used to determine the position of the tip of the ultrasound
probe. Additionally or alternatively, an EM sensor may be used to
track the tip of the ultrasound probe.
[0076] At 508, the catheter 608 and/or the probe 606 are moved, in
response to teleoperational, manual, or computer operated control,
within the anatomic passageways to locate the target structure for
display in an image generated by the probe. More specifically,
ultrasound images may be generated by the ultrasound probe within
the passageways. The ultrasound images allow a clinician to
visualize the area within the passageway and areas of tissue
outside of the passageways, immediately adjacent to and surrounding
the passageway. The ultrasound images also allow a clinician to
visualize tissue, including target tissue, located further away
from the wall of the passageway, for example, at a radial distance
of up to a few centimeters from the central axis of the probe,
depending upon the type of tissue being imaged.
[0077] At 510, after the target structure is detected by the probe
606, a clinician may identify the target structure in the image
using a pointing device. The image (e.g. the ultrasound image) may
be generated by a scan that is gated for respiratory and/or cardiac
cycles. A three-dimensional image may be constructed from
two-dimensional scans. The location identified by the pointing
device is identified and recorded as the pointer location data. At
512, the pointer location data is transformed from the image
coordinate system (X.sub.I, Y.sub.I, Z.sub.I) to the catheter
coordinate system (X.sub.C, Y.sub.C, Z.sub.C) or to the patient
coordinate system (X.sub.P, Y.sub.P, Z.sub.P) (which has been
previously registered to the catheter coordinate system).
[0078] At 514, the pointer location data can be used to apply an
offset correction (e.g., the offset correction vector 614) to the
location of the target structure identified initially in the
preoperative anatomic model. A revised target structure location
(e.g., revised target location P.sub.P) is computed based upon the
offset correction vector. The revised target location may be in the
catheter coordinate system and/or the patient coordinate system.
This revised target structure location may then be displayed to the
clinician in an image with the patient anatomical passageways
and/or the catheter. The probe 606 may then be removed from the
catheter 608. A biopsy tool or other interventional tool (e.g.,
instrument 662) may be inserted through the catheter to perform a
focal procedure (e.g., a biopsy) at the revised target location.
Optionally, the probe 606 may be reinserted through the catheter
608 after the interventional procedure. The reinserted probe may
conduct a scan and produce images for clinician review to confirm
whether the biopsied tissue was, in fact, the target tissue.
[0079] As described above, the probe 606 may be used for target
tissue confirmation and correction. In alternative embodiments, the
probe 606 and catheter 608 may be used to conduct the initial
navigation to the initial target location based on the
pre-operative images. In still other alternative embodiments, the
probe 606 and catheter 608 may be used for post-biopsy
confirmation. Because a lung passageway is generally filled with
air rather than fluid or tissue the effectiveness of ultrasound
imaging may be somewhat limited for longer-distance navigation
purposes. Ultrasound imaging may thus be particularly effective for
location confirmation/correction or for post-biopsy
confirmation.
[0080] Although the systems and methods of this disclosure have
been described 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 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-interventional
applications.
[0081] One or more elements in embodiments of the invention may be
implemented in software to execute on a processor of a computer
system such as control system 116. When implemented in software,
the elements of the embodiments of the invention are essentially
the code segments to perform the necessary tasks. The program or
code segments can be stored in a processor readable storage medium
or device that may have been downloaded by way of a computer data
signal embodied in a carrier wave over a transmission medium or a
communication link. The processor readable storage device may
include any medium that can store information including an optical
medium, semiconductor medium, and magnetic medium. Processor
readable storage device examples include an electronic circuit; a
semiconductor device, a semiconductor memory device, a read only
memory (ROM), a flash memory, an erasable programmable read only
memory (EPROM); a floppy diskette, a CD-ROM, an optical disk, a
hard disk, or other storage device, The code segments may be
downloaded via computer networks such as the Internet, Intranet,
etc.
[0082] Note that the processes and displays presented may not
inherently be related to any particular computer or other
apparatus. The required structure for a variety of these systems
will appear as elements in the claims. In addition, the embodiments
of the invention are not described with reference to any particular
programming language. It will be appreciated that a variety of
programming languages may be used to implement the teachings of the
invention as described herein.
[0083] 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 invention, and that the embodiments of the
invention not be limited to the specific constructions and
arrangements shown and described, since various other modifications
may occur to those ordinarily skilled in the art.
* * * * *