U.S. patent application number 16/877519 was filed with the patent office on 2020-09-03 for probe localization.
This patent application is currently assigned to Navix International Limited. The applicant listed for this patent is Navix International Limited. Invention is credited to Shlomo BEN-HAIM.
Application Number | 20200279412 16/877519 |
Document ID | / |
Family ID | 1000004838527 |
Filed Date | 2020-09-03 |
United States Patent
Application |
20200279412 |
Kind Code |
A1 |
BEN-HAIM; Shlomo |
September 3, 2020 |
PROBE LOCALIZATION
Abstract
A method of NM image reconstruction, including: (a) acquiring a
first set of NM data of a part of the body; (b) collecting a probe
position and/or probe NM data from an intrabody probe; (c)
reconstructing an NM image from said NM data using said collected
probe data. Also described is a method of navigating to a target in
a body, including: (a) acquiring a NM image of a part of the body;
(b) collecting NM data from an intrabody probe; (c) correlating
said image and said data; and (d) extracting location information
of said probe relative to said target based on said correlated
data.
Inventors: |
BEN-HAIM; Shlomo; (Milan,
IT) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Navix International Limited |
Road Town |
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VG |
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|
Assignee: |
Navix International Limited
Road Town
VG
|
Family ID: |
1000004838527 |
Appl. No.: |
16/877519 |
Filed: |
May 19, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15500190 |
Jan 30, 2017 |
10672152 |
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PCT/IB2015/055767 |
Jul 30, 2015 |
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16877519 |
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62030750 |
Jul 30, 2014 |
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62030825 |
Jul 30, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 6/541 20130101;
A61B 6/5288 20130101; A61B 6/5235 20130101; A61B 6/425 20130101;
G06T 2210/41 20130101; A61B 6/503 20130101; A61B 6/5294 20130101;
A61B 6/5205 20130101; A61B 6/4258 20130101; A61B 6/12 20130101;
A61B 6/547 20130101; A61B 6/487 20130101; A61B 2090/3966 20160201;
G06T 11/006 20130101; A61B 6/037 20130101; A61B 90/39 20160201 |
International
Class: |
G06T 11/00 20060101
G06T011/00; A61B 6/00 20060101 A61B006/00; A61B 6/03 20060101
A61B006/03; A61B 90/00 20060101 A61B090/00; A61B 6/12 20060101
A61B006/12 |
Claims
1. A method of navigating to a target in a body, comprising: (a)
acquiring a nuclear medicine (NM) image of a part of the body; (b)
collecting probe NM data from an intrabody probe; (c) automatically
correlating said image and said probe NM data to obtain correlated
data reflecting a match between structures in said image and
structures in the body portion of which said probe NM data is
collected; and (d) automatically extracting location information of
said intrabody probe relative to said target based on said
correlated data.
2. A method according to claim 1, wherein said collecting comprises
collecting when contacting a boundary of a lumen by said probe.
3. A method according to claim 1, comprising: (a) using said probe
NM data to generate a 3D map of position of at least part of a
boundary of said lumen and defining a boundary location and (b)
using said boundary location as a constraint during reconstruction
of probe NM data of said body portion.
4. A method according to claim 3, wherein said using as a
constraint comprises assuming emissions cannot come from said
lumen.
5. A method according to claim 1, wherein said extracting comprises
using said NM data as a constraint on probe location.
6. The method according to claim 1, comprising reconstructing in a
locality of a position of the probe when collecting probe data.
7. A method according to claim 1, comprises reconstructing an image
using said probe NM data.
8. A method according to claim 1, comprising reconstructing a local
NM image from said location information and said probe NM data.
9. The method of claim 1, comprising co-registering said location
information of said intrabody probe to said NM image.
10. The method of claim 1, wherein said probe is a catheter, said
lumen is in the heart and one or both of said NM data and said
probe NM data comprises emissions from mIBG.
11. A method according to claim 1, wherein said correlating
comprises correlating said collected data with an expected set of
measurements calculated using said NM image.
12. A method according to claim 1, wherein said extracting location
information comprises verifying a position of said probe.
13. A method according to claim 1, wherein said extracting location
information comprises selecting between alternative posited
positions of said probe.
14. A method according to claim 1, wherein said extracting location
information comprises determining a position of said probe.
15. A method according to claim 1, wherein said extracting location
information comprises determining a plurality of, but fewer than 5,
alternative positions of said probe.
16. A method according to claim 1, wherein said extracting location
information comprises determining a proximity to a hot spot.
17. A method according to claim 1, comprising combining said
extracted information with position data provided by a position
sensing system.
18. A method according to claim 17, wherein said combining
comprises providing a functional correction using said NM data to a
physical position indicated by said positioning data.
19. A method according to claim 1, wherein said collecting
comprises collecting data with a substantially omni-directional
sensor, with a directional sensitivity that is within a factor of
1:2 over all directions.
20. A method according to claim 19, wherein collecting comprises
moving said probe to collect a non-scalar indication of NM
data.
21. A method according to claim 1, wherein said collecting
comprises collecting data with an asymmetric sensor, with a
directional sensitivity that is within a factor more than 1:2 for
at least 1% of a field of view thereof.
22. A method according to claim 20, wherein collecting comprises
moving and/or rotating said probe to collect additional NM data for
use in said correlating.
23. A method according to claim 1, wherein said correlating
comprises correlating based on a pattern of peaks and/or amplitude
of peaks in said NM data.
24. Apparatus comprising circuitry with: (a) one or more inputs for
receiving NM image data; (b) one or more inputs for receiving probe
NM data and, configured to correlate the NM data and NM image data
and extracting location information of said probe therefrom.
25. Apparatus according to claim 24, as part of a system comprising
a catheter with a radiation sensor.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/500,190, filed on Jan. 30, 2017, which is a National
Phase of PCT Patent Application No. PCT/IB2015/055767, having
International filing date of Jul. 30, 2015, which claims the
benefit of priority under 35 USC .sctn. 119(e) of U.S. Provisional
Patent Application Nos. 62/030,750 and 62/030,825, both filed on
Jul. 30, 2014.
[0002] PCT Patent Application No. PCT/IB2015/055767 is also related
to:
[0003] PCT Patent Application No. PCT/IL2014/050086 filed Jan. 24,
2014,
[0004] PCT Patent Application No. PCT/IL2014/050088 filed Jan. 24,
2014,
[0005] PCT Patent Application No. PCT/IL2014/050089 filed Jan. 24,
2014,
[0006] PCT Patent Application No. PCT/IL2014/050090 filed Jan. 24,
2014,
[0007] PCT Patent Application No. PCT/IL2014/050246 filed Mar. 11,
2014; and
[0008] PCT applications and publications IB2015/053984 (filed on
May 27, 2015); WO2015/104672; WO2015/033319 and WO2015/033317.
[0009] The contents of the above applications are all incorporated
by reference as if fully set forth herein in their entirety.
FIELD AND BACKGROUND OF THE INVENTION
[0010] The present invention, in some embodiments thereof, relates
to navigating a probe, such as a catheter or other intrabody probe
and, more particularly, but not exclusively, to determining the
position and/or correct location of a probe using nuclear radiation
emissions.
[0011] In some publications it is suggested to use a model of the
anatomy, acquired, for example, by CT to constrain reconstruction
of NM (nuclear medicine) data.
SUMMARY OF THE INVENTION
[0012] There is provided in accordance with an exemplary embodiment
of the invention a method of NM image reconstruction,
compromising:
[0013] (a) acquiring a first set of NM data of a part of the
body;
[0014] (b) collecting a probe position and/or probe NM data from an
intrabody probe;
[0015] (c) reconstructing an NM image from said NM data using said
collected probe data.
[0016] Optionally, said collecting comprises collecting when
contacting a boundary of a lumen by said probe. Optionally, said
reconstructing comprises using said boundary location as a
constraint during reconstruction. Optionally, said using as a
constraint comprises assuming emissions cannot come from said
lumen. Optionally or alternatively, said reconstructing comprises
reprojecting said NM data using said constraint.
[0017] In some exemplary embodiments of the invention, the method
comprises reconstructing in a locality of said position.
[0018] In some exemplary embodiments of the invention, the method
comprises reconstructing at least a portion of a boundary of said
lumen using a plurality of positions to cover at least 16 square
centimeters and reconstructing comprises reconstructing an image of
tissue adjacent said portion.
[0019] In some exemplary embodiments of the invention, the method
comprises reconstructing at least a portion of a boundary of said
lumen using a plurality of positions to cover at least 16 square
centimeters and displaying a shape of said reconstruction with
associated NM data corresponding thereto.
[0020] In some exemplary embodiments of the invention, said
reconstructing comprises extending a model using said position of
boundary.
[0021] In some exemplary embodiments of the invention, said
reconstructing comprises reconstructing without a structural
image.
[0022] In some exemplary embodiments of the invention, said
reconstructing comprises reconstructing using a non-personalized
anatomical model. Optionally, the method comprises matching said
position to said model. Optionally, the method comprises estimating
thickness of a wall at said boundary using said matching and
wherein reconstructing uses said thickness. Optionally or
alternatively, the method comprises defining a constraint for
reconstructing a hot spot using said matching.
[0023] In some exemplary embodiments of the invention, the method
comprises collecting both position and probe NM data. Optionally,
said reconstructing comprises using said probe NM data for
reconstructing. Optionally or alternatively, said reconstructing
comprises using said probe NM data for identifying a hot spot.
Optionally or alternatively, the method comprises reconstructing a
local NM image from said position data and said NM probe data.
[0024] In some exemplary embodiments of the invention, the method
comprises co-registering said probe position to said NM image.
Optionally, said co-registering comprises acquiring an x-ray image
of said part and of at least one marker whose position with respect
to said NM data is known and registering said x-ray image to said
NM data and to said probe position.
[0025] In some exemplary embodiments of the invention, no position
data is collected using a position sensor. Optionally, the method
comprises using said probe NM data and said NM data to estimate a
position of the probe. Optionally or alternatively, the method
comprises using said probe NM data to reconstruct an image.
[0026] In some exemplary embodiments of the invention, said probe
is a catheter, said lumen is the heart and one or both of said NM
data and said probe NM data comprises emissions from mIBG.
[0027] There is provided in accordance with an exemplary embodiment
of the invention apparatus comprising circuitry with one or more
inputs for receiving NM data, receiving probe position and/or NM
data and reconstructing an NM image, for example, using methods as
described herein. Optionally, this is provided as part of a system
comprising a catheter with one or both of a radiation sensor and a
position sensor.
[0028] There is provided in accordance with an exemplary embodiment
of the invention a method of navigating to a target in a body,
comprising:
[0029] (a) acquiring a NM image of a part of the body;
[0030] (b) collecting NM data from an intrabody probe;
[0031] (c) correlating said image and said data; and
[0032] (d) extracting location information of said probe relative
to said target based on said correlated data.
[0033] Optionally, said correlating comprises correlating said
collected data with an expected set of measurements calculated
using said NM image. Optionally or alternatively, said extracting
location information comprises verifying a position of said probe.
Optionally or alternatively, said extracting location information
comprises selecting between alternative posited positions of said
probe. Optionally or alternatively, said extracting location
information comprises determining a position of said probe.
Optionally or alternatively, said extracting location information
comprises determining a plurality of fewer than 5 alternative
positions of said probe. Optionally or alternatively, said
extracting location information comprises determining a proximity
to a hot spot. Optionally or alternatively, the method comprises
combining said extracted information with position data provided by
a position sensing system.
[0034] Optionally, said combining comprises providing a functional
correction using said NM data to a physical position indicated by
said positioning data.
[0035] In some exemplary embodiments of the invention, said
collecting comprises collecting data with a substantially
omni-directional sensor, with a directional sensitivity that is
within a factor of 1:2 over all directions. Optionally, collecting
comprises moving said probe to collect a non-scalar indication of
NM data.
[0036] In some exemplary embodiments of the invention, said
collecting comprises collecting data with an asymmetric sensor,
with a directional sensitivity that is within a factor more than
1:2 for at least 1% of a field of view thereof. Optionally or
alternatively, collecting comprises moving and/or rotating said
probe to collect additional NM data for use in said
correlating.
[0037] In some exemplary embodiments of the invention, said
correlating comprises correlating based on a pattern of peaks
and/or amplitude of peaks in said NM data.
[0038] There is provided in accordance with an exemplary embodiment
of the invention apparatus comprising circuitry with one or more
inputs for receiving NM image data, receiving probe NM data,
correlating the NM data and NM image data and extracting location
information of said probe, for example as described herein.
[0039] Optionally, this is provided as part of a system comprising
a catheter with a radiation sensor.
[0040] There is provided in accordance with an exemplary embodiment
of the invention a method of NM image reconstruction,
compromising:
[0041] (a) acquiring a first set of NM data of a part of the
body;
[0042] (b) acquiring a second set of intrabody probe positions;
[0043] (c) reconstructing an NM image from said NM data using said
collected probe data.
[0044] There is provided in accordance with an exemplary embodiment
of the invention a method of functional image reconstruction,
compromising:
[0045] (a) providing a first set of anatomical data of a part of
the body;
[0046] (b) acquiring a second set of intrabody probe positions and
functional data using the probes;
[0047] (c) reconstructing an image from said functional data using
said collected probe data and said anatomical data.
[0048] Optionally, said functional data comprises NM data.
[0049] There is provided in accordance with an exemplary embodiment
of the invention a method of functional hybrid imaging,
compromising:
[0050] (a) acquiring a first set of functional data of a part of
the body;
[0051] (b) acquiring a second set of intrabody functional data;
[0052] (c) reconstructing the hybrid image from said data.
[0053] Optionally, said functional data comprises NM data.
[0054] Unless otherwise defined, all technical and/or scientific
terms used herein have the same meaning as commonly understood by
one of ordinary skill in the art to which the invention pertains.
Although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of
embodiments of the invention, exemplary methods and/or materials
are described below. In case of conflict, the patent specification,
including definitions, will control. In addition, the materials,
methods, and examples are illustrative only and are not intended to
be necessarily limiting.
[0055] As will be appreciated by one skilled in the art, aspects of
the present invention may be embodied as a system, method or
computer program product. Accordingly, aspects of the present
invention may take the form of an entirely hardware embodiment, an
entirely software embodiment (including firmware, resident
software, micro-code, etc.) or an embodiment combining software and
hardware aspects that may all generally be referred to herein as a
"circuit," "module" or "system".
[0056] Furthermore, aspects of the present invention may take the
form of a computer program product embodied in one or more computer
readable medium(s) having computer readable program code embodied
thereon. Implementation of the method and/or system of embodiments
of the invention can involve performing or completing selected
tasks manually, automatically, or a combination thereof. Moreover,
according to actual instrumentation and equipment of embodiments of
the method and/or system of the invention, several selected tasks
could be implemented by hardware, by software or by firmware or by
a combination thereof using an operating system.
[0057] For example, hardware for performing selected tasks
according to embodiments of the invention could be implemented as a
chip or a circuit. As software, selected tasks according to
embodiments of the invention could be implemented as a plurality of
software instructions being executed by a computer using any
suitable operating system. In an exemplary embodiment of the
invention, one or more tasks according to exemplary embodiments of
method and/or system as described herein are performed by a data
processor, such as a computing platform for executing a plurality
of instructions. Optionally, the data processor includes a volatile
memory for storing instructions and/or data and/or a non-volatile
storage, for example, a magnetic hard-disk and/or removable media,
for storing instructions and/or data.
[0058] Optionally, a network connection is provided as well. A
display and/or a user input device such as a keyboard or mouse are
optionally provided as well.
[0059] Any combination of one or more computer readable medium(s)
may be utilized. The computer readable medium may be a computer
readable signal medium or a computer readable storage medium. A
computer readable storage medium may be, for example, but not
limited to, an electronic, magnetic, optical, electromagnetic,
infrared, or semiconductor system, apparatus, or device, or any
suitable combination of the foregoing. More specific examples (a
non-exhaustive list) of the computer readable storage medium would
include the following: an electrical connection having one or more
wires, a portable computer diskette, a hard disk, a random access
memory (RAM), a read-only memory (ROM), an erasable programmable
read-only memory (EPROM or Flash memory), an optical fiber, a
portable compact disc read-only memory (CD-ROM), an optical storage
device, a magnetic storage device, or any suitable combination of
the foregoing. In the context of this document, a computer readable
storage medium may be any tangible medium that can contain, or
store a program for use by or in connection with an instruction
execution system, apparatus, or device.
[0060] A computer readable signal medium may include a propagated
data signal with computer readable program code embodied therein,
for example, in baseband or as part of a carrier wave. Such a
propagated signal may take any of a variety of forms, including,
but not limited to, electro-magnetic, optical, or any suitable
combination thereof. A computer readable signal medium may be any
computer readable medium that is not a computer readable storage
medium and that can communicate, propagate, or transport a program
for use by or in connection with an instruction execution system,
apparatus, or device.
[0061] Program code embodied on a computer readable medium may be
transmitted using any appropriate medium, including but not limited
to wireless, wireline, optical fiber cable, RF, etc., or any
suitable combination of the foregoing.
[0062] Computer program code for carrying out operations for
aspects of the present invention may be written in any combination
of one or more programming languages, including an object oriented
programming language such as Java, Smalltalk, C++ or the like and
conventional procedural programming languages, such as the "C"
programming language or similar programming languages. The program
code may execute entirely on the user's computer, partly on the
user's computer, as a stand-alone software package, partly on the
user's computer and partly on a remote computer or entirely on the
remote computer or server. In the latter scenario, the remote
computer may be connected to the user's computer through any type
of network, including a local area network (LAN) or a wide area
network (WAN), or the connection may be made to an external
computer (for example, through the Internet using an Internet
Service Provider).
[0063] Some aspects of the present invention are described below
with reference to flowchart illustrations and/or block diagrams of
methods, apparatus (systems) and computer program products
according to embodiments of the invention. It will be understood
that each block of the flowchart illustrations and/or block
diagrams, and combinations of blocks in the flowchart illustrations
and/or block diagrams, can be implemented by computer program
instructions. These computer program instructions may be provided
to a processor of a general purpose computer, special purpose
computer, or other programmable data processing apparatus to
produce a machine, such that the instructions, which execute via
the processor of the computer or other programmable data processing
apparatus, create means for implementing the functions/acts
specified in the flowchart and/or block diagram block or
blocks.
[0064] These computer program instructions may also be stored in a
computer readable medium that can direct a computer, other
programmable data processing apparatus, or other devices to
function in a particular manner, such that the instructions stored
in the computer readable medium produce an article of manufacture
including instructions which implement the function/act specified
in the flowchart and/or block diagram block or blocks.
[0065] The computer program instructions may also be loaded onto a
computer, other programmable data processing apparatus, or other
devices to cause a series of operational steps to be performed on
the computer, other programmable apparatus or other devices to
produce a computer implemented process such that the instructions
which execute on the computer or other programmable apparatus
provide processes for implementing the functions/acts specified in
the flowchart and/or block diagram block or blocks.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0066] Some embodiments of the invention are herein described, by
way of example only, with reference to the accompanying drawings.
With specific reference now to the drawings in detail, it is
stressed that the particulars shown are by way of example and for
purposes of illustrative discussion of embodiments of the
invention. In this regard, the description taken with the drawings
makes apparent to those skilled in the art how embodiments of the
invention may be practiced.
[0067] In the drawings:
[0068] FIG. 1 is a schematic block diagram of a catheter-type probe
and imaging system in accordance with some exemplary embodiments of
the invention;
[0069] FIG. 2 is a schematic showing of a catheter for use in the
system of FIG. 1, in accordance with some exemplary embodiments of
the invention;
[0070] FIG. 3A is a flowchart of a method of registration using the
system of FIG. 1, in accordance with some exemplary embodiments of
the invention;
[0071] FIG. 3B is a flowchart of a method of image reconstruction
using the system of FIG. 1, in accordance with some exemplary
embodiments of the invention;
[0072] FIG. 4 is a schematic showing of navigating to a target in
accordance with some exemplary embodiments of the invention;
[0073] FIG. 5 is a flowchart of a method of navigating using
catheter based sensing, in accordance with some exemplary
embodiments of the invention; and
[0074] FIG. 6 is a schematic showing of signals detected by a probe
following the showing of FIG. 4, in accordance with some exemplary
embodiments of the invention.
DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION
[0075] The present invention, in some embodiments thereof, relates
to navigating a probe and, more particularly, but not exclusively,
to determining the location and/or correct location of a probe
using nuclear radiation emissions.
Overview
[0076] A broad aspect of some embodiments of the invention relates
to using a probe position for assisting NM image reconstruction
and/or for reconstruction (e.g., into an image or map) of other
functional data which has a low anatomical accuracy (e.g., lower
than CT, for example, lower than 10 or 5 mm voxels). In some
exemplary embodiments of the invention, probe position is used to
define anatomical locations which can be used to restrict
reconstruction of the image so as to provide a possibly more
accurate (e.g., anatomically correct) reconstruction.
[0077] In some exemplary embodiments of the invention, a plurality
of probe positions are used to generate a representation of a
structure of a body part. Optionally, previously and/or
co-collected NM data set is registered to the representation and
the representation is used to assist in reconstruction of the NM
data into an image and/or into discrete data suitable for overlap
on a map or other model. In one example, the representation
indicates a location of walls of a body organ and the
reconstruction constrains the NM data to reflect emissions from the
wall, rather than from voids. Optionally or alternatively, the
reconstruction is used to select data from the NM data to be used
for analysis. Optionally or alternatively, the reconstruction is
used to identify, in the NM data, location(s) of interest and/or
indicate a desired identification of an object for the NM
reconstruction, for example, the identification of a ganglion.
[0078] In some exemplary embodiments of the invention, the
reconstruction does not use a previously acquired structural 3D
image, such as a CT image. Optionally or alternatively, the
reconstruction does not use an anatomical model.
[0079] In some exemplary embodiments of the invention, the probe
positions are used to extend a previously acquired 3D image (e.g.,
structural and/or functional) and/or a model. In one example, the
extension is by modifying the model and/or model parameters
according to actual and/or current tissue shape. For example, the
image and/or model is deformed and/or constrained to match measured
probe locations. Optionally or alternatively, extension is in time,
for example, starting from a model at one part of a cycle of
deformation of an organ, probe positions measure the position of
organ parts over time and show how the model is to be deformed from
one state to its shape in other parts of the cycle.
[0080] Optionally or alternatively, extension is in space, for
example, if the model shows only part of the organ, the positions
can be used to extend the model to unmodeled portions and/or to
provide more resolution within the model (e.g., between points of
the model).
[0081] A broad aspect of some embodiments of the invention relates
to using NM emissions to locate a catheter or other intrabody probe
with respect to a navigation target.
[0082] In some exemplary embodiments of the invention, the locating
comprises determining if the catheter is at an expected
location.
[0083] In some exemplary embodiments of the invention, the locating
comprises determining if the catheter is at and/or correctly
oriented with respect to a navigation target.
[0084] In some exemplary embodiments of the invention, the locating
comprises determining a general position of the catheter with
respect to a navigation target.
[0085] In some exemplary embodiments of the invention, the locating
comprises collecting information to assist in reconstructing an
image of the target location.
[0086] In some exemplary embodiments of the invention, navigating
is provided which uses both NM location information and other
information, such as a previously or co-acquired image (e.g.,
structural and/or functional).
[0087] In some exemplary embodiments of the invention, locating
uses a map of radiation emission previously or co acquired.
Optionally, such a map is used to estimate what signals should be
captured by an intrabody probe and/or the likelihood that captured
signals reflect the target location.
[0088] In some exemplary embodiments of the invention, locating
comprises locating using a position sensor on the probe which is
optionally co-registered with other data.
[0089] In some exemplary embodiments of the invention, such a
position sensor on the catheter is used to co-register the catheter
with a co-acquired nuclear medicine image of, for example, the
heart. Optionally, the patient has affixed thereto a position
sensor or other marker (e.g., visible in x-ray) which is also
visible in a NM imager (e.g., including radioactive material). The
catheter is then used to contact various parts of an organ, e.g.,
the heart and collected information therefrom. In exemplary
embodiments of the invention, such contacting can be used to
determine a heart wall (or other lumen wall, e.g., for other
organs) location. Optionally or alternatively, such contacting is
used to extract from the NM image and/or NM data the expected
emission to be measured by the catheter (if the catheter has a
radiation sensor). Optionally or alternatively, actually measured
emissions and/or determined wall locations are used to guide a
reconstruction process of the NM image. In one example, the NM
image is used to search for ganglions or other ANS (Autonomic nerve
system) components or other parts of an image which are localized
and have a relatively high (or low) activity.
[0090] For example, wall location can indicate where such a part
may be physically located and thus, to be searched for, e.g., using
a window on an image or data. In another example, emission
measurements can be used as a seed for indicating a possible
location for a ganglion.
[0091] In some exemplary embodiments of the invention, the
knowledge of the probe used for sampling data and its related
sensing area (e.g., a functional, f which indicates a spatial
behavior of sensing) are superimposed (location wise) on a
co-located image, such as an anatomical image. In some exemplary
embodiments of the invention, the multiple functionals, f, acquired
at different locations and/or orientations are input into a maximal
likelihood reconstruction algorithm that has the anatomical
knowledge as a prior constraint and uses the set of functionals and
their sampling locations to generate a reconstructed NM image of
the organ.
[0092] An aspect of some embodiments of the invention relates to
interplay between location information and the physical information
sensed at a location. In some exemplary embodiments of the
invention, the information regarding location is improved using
information gathered from the physical properties at a location
and/or vice versa. Optionally, multiple iterations are provided of
one information improving different information.
[0093] In some exemplary embodiments of the invention, even if the
position sensor is precise, if tissue moves and/or deforms, the
position relative to the tissue and/or anatomical objects may be
less precise, while what may be more important is the position
relative to functional parts. Optionally, a functional position is
used to correct/update/replace the signal.
[0094] In one example, the knowledge that a blood vessel has a wall
and the fact that from physical information one can detect the
location of the wall, allows one to relate to this information and
use it to gain more information on the location of the probe (e.g.,
select between alternative probe position reconstructions), which
may be useful, for example, in impedance based position
sensing.
[0095] In another example, detecting that a catheter contacts a
wall allows measured functional information (e.g., conductivity or
radiation) to be reconstructed more accurately.
[0096] In some exemplary embodiments of the invention, the gain of
information from the location or the physical property at a
location can be further augmented if there is a co-registered set
of anatomical information (such as a CT or an MRI). However, in
some embodiments of the invention, what is used are rules, for
example, that blood vessels are cylindrical and/or general
anatomical models, such as the general layout and diameter of blood
vessels and/or other hollow organs. Optionally or alternatively,
conductivity is used to distinguish walls from blood, based on a
threshold value or other method which distinguishes between values
representative of wall tissue and values representative of
blood.
[0097] In some embodiments, the bifurcations of blood vessels
(e.g., as detected using a position sensor) is used to identify a
location where the anatomical constraints (e.g., used to constrain
a position reconstruction of the probe) change (e.g., more than one
cylindrical lumen to be in).
[0098] An aspect of some embodiments of embodiments of the
invention relates to reconstructing a functional image (e.g., NM)
using both data acquired from outside the body and data acquired
from inside the body. In exemplary embodiments of the invention,
the data acquired inside the body is acquired using a probe and is
used to enhance data acquired from outside the body. Optionally,
position sensing of the probe is used to correlate the two types of
data and/or to help reconstruct one or both types of data.
[0099] In some exemplary embodiments of the invention, the data
acquired from outside the body and the data acquired from inside
the body are of different modalities.
[0100] Optionally or alternatively, the data is of a same modality
but of a different type, for example, NM data using different
tracers and/or acquired at different physiological states.
[0101] An aspect of some embodiments of the invention relates to
functional image reconstruction from functional data using a
plurality of probe positions. Optionally, the functional data is
acquired by the probes. Optionally or alternatively, the functional
data is acquired using a different imager on the same patient. For
example, an external NM imager may be used, for example an imager
with detectors which can be brought close to the tissue being
imaged.
[0102] In some exemplary embodiments of the invention, the probe
positions are used to define one or more anatomical restrictions on
reconstruction. Optionally, these restrictions are also defined
using separately provided anatomical data (e.g., images, models,
rules, from same and/or other patients). Optionally, the provided
anatomical data is used as a model to be corrected by said probe
position data. Optionally or alternatively, the anatomical data is
used to improve positioning data of the probes.
[0103] Before explaining at least one embodiment of the invention
in detail, it is to be understood that the invention is not
necessarily limited in its application to the details of
construction and the arrangement of the components and/or methods
set forth in the following description and/or illustrated in the
drawings and/or the Examples. The invention is capable of other
embodiments or of being practiced or carried out in various
ways.
Exemplary System
[0104] FIG. 1 is a schematic block diagram of a catheter and
imaging system 100 in accordance with an exemplary embodiment of
the invention.
[0105] A patient 102 includes a heart (or other organ) 104 with a
target 106 characterized by a radioactive emission when patient 102
is injected with a suitable radioactive marker.
[0106] An optional x-ray imager 108 (e.g., a fluoroscope) acquires
an image of patient 108 with a field of view 110 and optionally one
or more radio-opaque markers 112. As noted below, markers 112 may
also be radioactive.
[0107] In an exemplary embodiment of the invention, system 100 is
used with a catheter 114. A position sensing system 116 may be used
to determine the position of catheter 114 (e.g., a tip thereof)
and/or of other parts of system 100, such as markers 112 (e.g., by
touching a position sensor there to, or if they include a position
sensor).
[0108] NM (Nuclear medicine) data 118 may be provided, for example,
from storage and/or using a NM imager (not shown). Optionally, the
NM imager is used while catheter 114 is inside patient 102.
[0109] A processor 120 optionally analyses an acquired image from
x-ray imager 108 for detecting markers 112 therein and optionally
is used (e.g., as described below) to register the NM data to the
catheter location and/or x-ray image. Optionally or alternatively,
for example, as described below, processor 120 reconstructs a NM
image from NM data 118, using positions indicated by position
sensing system 116. In some exemplary embodiments of the invention,
only processor 120 is provided and the other components are
standard components.
[0110] A display 122 optionally shows one or more of a
reconstructed NM image, catheter position (e.g., in space) location
(e.g., relative to anatomical locations) and/or the image from
imager 108.
Exemplary Catheter
[0111] FIG. 2 is a schematic showing of a catheter 200 for use in
the system of FIG. 1, in accordance with some exemplary embodiments
of the invention. Optionally, catheter 200 is designed for
traveling in blood vessels, for example, including a hydrophobic
coating and/or has a suitable diameter (e.g., less than 5 mm, 3 mm,
2 mm or intermediate or greater sizes) and/or a suitable length
(e.g., between 10 cm and 300 cm, for example, between 50 and 250
cm). Optionally or alternatively, catheter 202 is in the form of an
endoscope (e.g., and may include an imager thereon), for example,
for traveling through natural and/or unnatural voids in the body.
Other intrabody probes (e.g., flexible, bendable and/or rigid), may
be used instead of a catheter, for example, a colonoscope or other
imaging probe.
[0112] As shown, catheter 200 has a body 202 and one or more
components, optionally at or near its distal tip. In an exemplary
embodiment of the invention, an optional position sensor 204 (e.g.,
a magnetic field sensor as used in the Biosense-Webster CARTO.RTM.
system), is provided. Optionally or alternatively, one or more
electrodes 212 is provided, for sensing and/or for stimulating
tissue. Optionally or alternatively, other tools, for example, one
or more of a biopsy snare, injection catheter, cryo-catheter or
probe, and microwave probe or catheter, are provided.
[0113] Optionally or alternatively, a radiation sensor 206 is
provided. Optionally, radiation sensor 206 is an omni-directional
sensor. Optionally or alternatively, sensor 206 includes shielding
208 at one or more sides thereof, and/or is otherwise configured
have a non-spherical sensitivity. Optionally or alternatively,
shielding 206 includes apertures 210 (optionally shielding 208
being in the form of collimators), to provide (relatively) narrow
field sensitivity. Optionally, the detector has a factor of
sensitivity of greater than 1:1.5, 1:2, 1:4, 1:6, 1:10 or
intermediate factors between different directions of viewing, for
at least 10% (vs. a different 10%) of a surface area of the
detector.
[0114] Optionally, the various sensors and/or electrodes
communication using a wire or bundle that runs along catheter body
202.
[0115] In some embodiments position is detected using non-sensing
methods, for example, by extracting catheter position for one or
more x-ray images or by analyzing signals injected by the electrode
and detected using one or more surface electrode.
Exemplary Registration
[0116] FIG. 3A is a flowchart 300 of a method of registration using
the system of FIG. 1, in accordance with some exemplary embodiments
of the invention.
[0117] At 302, one or more markers are optionally attached to
patient 102. Optionally, the markers are both radio-opaque and
radioactive. Optionally, the markers include a position sensor
therein. Optionally, markers as described in co-filed application
of same date and inventor Ben-Haim with PCT Patent Application No.
PCT/IB2015/055772 filed Jul. 30, 2015, now published as
WO2016/016839, and which entered National Phase as U.S. patent
application Ser. No. 15/500,189, filed Jan. 30, 2017, published as
2017-0278280-A1, are used, which include both a radio-opaque
section and a radioactive section (optionally removable).
[0118] At 304, an NM image of the patient is acquired. Optionally,
the NM image is registered to body coordinates using the markers.
Optionally or alternatively, other registration methods are used,
for example, using a transmission CT image. However, a particular
feature of some embodiments of the invention is that no CT image is
acquired, thus potentially reducing the patient radiation load.
[0119] At 306, a catheter (e.g., catheter 200) is used to acquire
locations at a plurality of reference points (e.g., in the heart,
two or three or more of LSPV, LIPV, RSPV, RIPV, LV Apex). In an
exemplary embodiment of the invention, the locations are acquired
by navigating the catheter to a location and then "capturing" and
"naming" the position of the catheter to processor 120.
[0120] At 308, the catheter and markers are optionally imaged using
an x-ray imager. In some embodiments, no X-ray imaging is used and,
for example, the markers need not be radio-opaque. Instead, the
positions of the markers are registered to the position sensor, for
example by contacting of the catheter or a different position
sensor thereto.
[0121] At 310, the positions of the markers is acquired, for
example, by contacting with a position sensor (e.g., optionally
before 308 or 306).
[0122] At 312, the NM data can be registered to the x-ray image,
markers and/or position sensing space, using the above
measurements. In an exemplary embodiment of the invention, this
registration is used to register the instant catheter tip location
to the NM data space.
[0123] In some exemplary embodiments of the invention, other
registration methods are used to register the NM data space to the
location of the catheter tip. In one example, position sensing is
replaced or enhanced by a method of tracking displacement whereby
an integration of 3D displacements from a known location are used
to determine a current location. Optionally, this displacement is
periodically zeroed by returning the catheter to a known location
(e.g., a fixed part, such as a valve or apex), of the heart.
Optionally, the displacements are determined using a 3D
accelerometer and/or gyroscope at the catheter tip, for example,
using calculations of a type used in INS (inertial navigation
systems).
Exemplary Image Reconstruction
[0124] FIG. 3B is a flowchart 320 of a method of image
reconstruction using the system of FIG. 1, in accordance with an
exemplary embodiment of the invention, in which locations of the
catheter tip are used to constrain NM image reconstruction,
optionally by defining location where emission is expected and/or
locations where emission is unexpected.
[0125] At 322, the tip (or other known part) of catheter 200 is
placed against a wall or other structure from which and/or relative
to which emissions are expected or expected not to be. This can be
used, for example, to assess the shape of a lumen surrounding
catheter 202 and/or to guide data acquisition and/or analysis, for
example, as described below.
[0126] At 324, a radiation signal is optionally sensed (e.g., if
sensor 206 is provided). In an organ such as the heart, signal from
tissue directly adjacent the sensor and/or in its main field of
view is expected to be a significant if not a majority of a signal
acquired by sensor 206. If the catheter is against tissue that does
not uptake the tracer, no signal from directly adjacent tissue is
to be expected. Optionally, the sensed signal is marked with
respect to catheter tip position and/or orientation (e.g., using
position sensor 204). In some embodiments, for example, as
described below, a position sensor is not provided, instead, the
sensed radiation signal is used for position estimation with and/or
without wall contact.
[0127] At 326, a plurality of tip positions are used to reconstruct
the shape of at least part of the lumen (e.g., a heart chamber or
wall section thereof, for example, a left ventricle or a left or a
right atrium). Optionally, electrical sensing is used to gate the
position sensing to a same part of the cardiac cycle for all
measurements. Optionally or alternatively, a plurality of positions
are acquired at each wall contact, allowing the location of the
wall (and/or lumen shape) at different parts of the cardiac cycle
to be reconstructed, optionally with measurements being binned
according to cardiac cycle, extracted, for example, from ECG data
and/or from change in position of the catheter within a cardiac
cycle. Such windowing, triggering and/or gating is optionally
and/or alternatively used also for collecting radiation
information. Optionally, catheter movement within 1 second is
assumed to be due to tissue movement and not due to operator
movement. Optionally or alternatively, an operator can indicate
when he is not providing movement, for example, using a foot
control. Optionally or alternatively, a sensor in the port and/or
catheter can indicate relative movement of the catheter and port.
Optionally or alternatively, a sensor in a manipulator (e.g., for
bending catheters) is used to detect human, vs. tissue caused
movement. Optionally or alternatively, an x-ray image is analyzed
to determine a cause of movement, for example, by measuring a
catheter length inside the body and/or movement of a catheter tip
relative to heart wall or other anatomical markers.
[0128] In an exemplary embodiment of the invention, the wall
locations are used to build a mesh model of the lumen wall.
Optionally, this model is correlated with a known anatomy (e.g.,
general human anatomy and/or a previously acquired image).
Optionally, such correlation may be used to determine structural
feature snot at the lumen surface, for example, wall thickness,
identification of the anatomical location and/or expected nearby
possibly emitting structures and/or non-emitting structures, for
example, the mitral valve annulus ring will have different (if any)
emitting properties and has a generally known shape. Optionally,
wall thickness is used for reconstructing, for example as described
below. Optionally or alternatively, anatomical location is used to
refer back to an anatomical model which may be used, for example,
for navigation and/or diagnosis (e.g., with the data projected onto
such a model, rather than using only the acquired mesh).
Optionally, the anatomical model is modified (e.g., resized,
rotated and/or deformed) to match or approximate the acquired mesh
model. Optionally, the deformation is local, for example, to areas
of between 1 and 5 cm in diameter.
[0129] In an exemplary embodiment of the invention, the mesh has an
average cell size (e.g., corresponding to spatial sampling rate) of
less than 30 mm, less than 20 mm, less than 10 mm or intermediate
or greater diameters, for an area of, for example, at least 10
cm{circumflex over ( )}2, 20 cm{circumflex over ( )}2, 40
cm{circumflex over ( )}2, 80 cm{circumflex over ( )}2 or
intermediate mesh sizes. Optionally, the mesh cell size is selected
according to a desired resolution and/or a desired motion-related
accuracy. For example, mesh size may be smaller than 5 times, 3
times, 2 times, or 1 time the wall thickness. In an exemplary
embodiment of the invention, the cardiac cycle is divided into at
least 2, 3, 4, 5, 8 or smaller or intermediate numbers of different
states. The number of states may be different for different parts
of the heart, for example, fewer states where there is less data
and/or less motion.
[0130] At 328, NM data correlated with the catheter tip position is
optionally extracted. Optionally, a predefined shape for extraction
is provided. Optionally or alternatively, a shape based on the
anatomy is extracted. Optionally, the activity in this extracted
portion is compared to the activity sensed by the catheter. This
may be used, for example, for navigation and/or to detect changes
in activity. Optionally or alternatively, the activity is displayed
(e.g., color coded) on display 122, optionally overlaying the
anatomical model. Optionally, local activity is activity in a cube
with a width of 3 mm, length of 3 mm and height of 8 mm with
respect to the tip (e.g., long axis perpendicular or at an angle to
lumen wall).
[0131] At 330, a reconstruction zone is optionally defined. In some
exemplary embodiments of the invention, the reconstruction zone
defines the walls of the lumen, for example, based on the acquired
positions and/or model. Optionally or alternatively, the
reconstruction zone defines a location relative to the probe, for
example, wall in contact with the probe and/or tissue on the other
side of the wall.
[0132] At 332, the NM data is reconstructed using the defined
reconstructed zone. In some exemplary embodiments of the invention,
NM data is reconstructed and/or re-projected to be constrained to
avoid the hollow of the lumen. In some exemplary embodiments of the
invention, determination of the wall is used to define locations
where high emitting objects (e.g., ganglions) may be located.
Reconstruction comprises searched for such objects and/or
determining if a reconstruction of a ganglion at such locations is
reasonable. Exemplary reconstruction techniques which may be used
are described in PCT publication WO2014/115148, the disclosure of
which is incorporated herein by reference.
[0133] Optionally, such searching is in a volume within (for
example) 1 cm distance from the lumen wall.
[0134] In some exemplary embodiments of the invention,
reconstruction comprises reconstructing a locality of the probe,
for example, using extracted NM data and/or sensed NM data.
Optionally, such reconstruction uses the wall location to limit
reconstruction from "leaking" into the lumen.
[0135] In some exemplary embodiments of the invention, the NM
imaging comprises imaging using a nerve imaging agent such as mIBG,
and the searching comprises searching for ganglions as being
objects of a generally spherical or ellipsoid or almond like shape
and a size of long axis of between 5 and 22 mm. It is noted that
mIBG may also be used to detect androgenic synapses in muscle
tissue, possibly indicating a level of nervous control of such
tissues.
[0136] In some exemplary embodiments of the invention, the NM
imaging comprises imaging using a muscle metabolic agent, such as
Sestamibi and the imaging indicates the extent and/or viability of
muscle, such as cardiac muscle.
[0137] In some exemplary embodiments of the invention, the NM data
and the NM probe data relate to emissions of different radioactive
tracers. For example, the NM data may be of Sestamibi and the probe
data of mIBG. Optionally or alternatively, the NM data includes
multiple tracer data. In some exemplary embodiments of the
invention, the NM data is useful, for example, for navigation
and/or reconstruction, as all the tracers can share of different
concentration in solid tissue as compared to blood (e.g., and can
be used to indicate at least part of the shape of the heart,
possibly enough for model matching with boundary locations
determined by the position sensor).
[0138] Optionally or alternatively, the relative positions of the
two tracers may be expected, for example, mIBG concentrations being
within or near viable muscle indicated by Sestamibi. Optionally or
alternatively, the probe is used to identify location having a
mismatch between the radiation indicated in the NM data (e.g.,
Sestamibi) and instant radiation (e.g., mIBG). This may indicate
various pathologies, for example, as described in the above
mentioned related applications, for example, WO2015/033317, the
disclosure of which is incorporated herein by reference.
Exemplary Navigation
[0139] In an exemplary embodiment of the invention, NM data
collected by catheter 200 is used to assist in navigating to a
target and/or otherwise determining the catheter location.
[0140] FIG. 4 is a schematic showing 400 of navigating to a target
in accordance with an exemplary embodiment of the invention. In the
example of navigating to a hollow organ, such as a heart via the
vascular system, a catheter 200 may travel along a lumen 402 (e.g.,
the aorta), to an organ 404 (e.g., the heart) to a target location
410 (e.g., a location to be ablated in organ 404). A probe other
than catheter 200 may be used and for other organs. Also, the
pathway may be via tissue or an artificial lumen, rather than
natural lumens such as the vascular system or GI tract. In FIGS. 4,
412 and 408 indicate other radio-emissive locations in the organ
which are not the target and a radio-emissive location 406 (e.g.,
the liver) which is not in organ 404. References 414-424 indicate
various locations at which navigation activities are carried out in
accordance with some embodiments of the invention and as described
below. FIG. 6, explained below, shows radiation measurements taken
at such locations, in accordance with some embodiments of the
invention.
[0141] FIG. 4 illustrates various ways of navigating, one or more
of which may be applied in some embodiments of the invention. FIG.
5 is a flowchart 500 of a method of navigating using catheter based
sensing, in accordance with an exemplary embodiment of the
invention.
[0142] At 502, the catheter location is optionally determined using
a position sensor (e.g., 204). It should be noted that there are
several positioning coordinates to be considered in some
embodiments of the invention. One is the physical location, for
example, absolute location in space and/or relative to an
anatomical location, usually denoted herein as "position". Another
is a functional location, relative to a function in tissue (e.g.,
distance from a metabolic hotspot). Such a position may also be
binary, being either at the location or not. Functional location
and anatomical location are usually denoted herein as
"location".
[0143] At 504, a radiation signal is sensed from catheter 200. In
some embodiments, the signal is scalar and indicates a strength of
detected emission. This may correlate with a distance from one or
more hotspots but will generally not give direction.
[0144] Optionally, the catheter is moved, so as to provide multiple
such measurements, optionally using a position sensor and/or
measurement of change in catheter insertion, to build a spatial or
linear map of different measurements at different locations.
Optionally or alternatively, the catheter is asymmetrically
sensitive and is optionally rotated so as to provide different
measurements from different directions.
[0145] At 506, expected measurements are determined. For example,
he expected radiation measurements may be calculated from the
position of the catheter, the detector spatial sensitivity and a
previously or co acquired NM data set. Optionally, the data set is
corrected for an effect of delay between imaging and catheter
navigation, for example, using models of tracer redistribution
and/or decay. Optionally or alternatively, catheter measurements
(or measurements with a different radiation sensor, for example,
near the heart and/or the liver, optionally from outside the body)
at one or more locations are used to normalize the NM data
model.
[0146] In some cases location data is used. For example, using a
previously or co-acquired structural data, an expected position of
the catheter (e.g., "should be within aorta") is provided.
Optionally, the position data (e.g., a series of locations and/or
orientations) is used to detect motion along a straight and/or
curved and optionally constricted pathway (e.g., a particular blood
vessel as an example of a pathway with a generally known geometry),
for example, detecting the traversal of an aortic arch based on a
180 degree change in catheter path and a suitable bending
radius.
[0147] At 508, the expected data is correlated with the measured
position and/or radiation data. The correlation may be used, for
example, to find a correct match, to find a best match and/or
reject matches.
[0148] At 510, in some exemplary embodiments of the invention, a
correct match is optionally used to determine a location of the
catheter based on matching of data to the expected data associated
with a certain position (e.g., verification). Optionally or
alternatively, a correct match is used by searching the space of
possibilities for a position where the measurements match the
expected data. This may be used to find a location. Various search
mechanism may be used, including, for example, pattern matching and
a priori-reduction of possible matches by processing the data to
extract one or more features which are expected in the measured
data.
[0149] In some exemplary embodiments of the invention, a correct
match is used to verify if the catheter is at an expected location
or not. Optionally, any match below a threshold is indicated as a
failure.
[0150] In some exemplary embodiments of the invention, a best match
is used to estimate a catheter position. Optionally, matching
comprises using both position data and radiation data, for example,
weighted and/or cross-verified (e.g., a match is considered only if
both position and radiation data meet certain quality
criteria).
[0151] Optionally or alternatively, a best match is used to decide
between a small number of alternative navigation options. For
example, a best match may be used to indicate if the catheter is in
one heart chamber or another, or if the target is generally to the
right or to the left.
[0152] Referring back to FIG. 4 for examples or using position data
and/or radiation data, at 414, radiation data may be unable to
indicate more than a very general position. Position data may
indicate if the catheter left vessel 402 to a branching vessel.
[0153] At 416, position data may indicate the curve in travel and
radiation sensing may indicate a proximity to radiation sources
and/or the general spatial distribution of 406 on one side and
408-412 on the other side of the position.
[0154] At 418, as organ 404 is entered, position data may indicate
ability to move in various directions and radiation data may
indicate radiation sources at relative proximity and at various
directions.
[0155] At 420, radiation measurement signals are expected to
increase, indicating that even a scalar measurement of radiation
signal may be used to assist in navigation (e.g., detecting
increase as target 410 is approached).
[0156] At 422, near a hotspot 412 (not target 410), radiation
intensity may be correct, however, position and/or radiation
signals from other directions may be incorrect.
[0157] At 424, all the indicators match up. Optionally, radiation
intensity is used to verify maximum proximity to a hot spot and/or
guide rotation of catheter 200 so that, for example, a desired
portion thereof (if any, such as an ablation mechanism) is in
contact with the wall of organ 404.
[0158] Optionally or alternatively, to position data, other data
may be used to assist in navigation. For example, structural data
such as from a CT, ultrasound, MRI or x-ray image may be used to
provide anatomical constraints on possible locations for the
catheter. Optionally or alternatively, functional data, such as
electric or magnetic measurements may indicate relative position on
and/or distance from the wall of an electrically active organ.
Optionally or alternatively, other data may be collected and/or
displayed, for example, one or more of pressure, displacement, heat
and/or conductivity. In an exemplary embodiment of the invention,
such other data may be useful if there is a map indicating expected
properties and/or values for such data at each point and/or at
points of interest.
Exemplary Correlation for Navigation
[0159] FIG. 6 is a schematic showing of signals which might
detected by a probe following the showing of FIG. 4, in accordance
with an exemplary embodiment of the invention.
[0160] The traces shown in FIG. 6 are angular traces (2D for
simplicity of showing, but may be 3D), with the x-axis being an
angle (straight ahead being at the middle of the x-axis) and the
y-axis indicating amplitude of signal. Noise is generally not
shown, but it is noted that the signal is generally noisy, which
may lead to a need to collect data over a period of time.
Optionally or alternatively, data is collected as the catheter is
moved and navigational conclusions updated during such movement and
displayed. Optionally, a display shows both an anatomical (e.g.,
relative to torso markers 112 and/or internal anatomy) and/or
functional position. In some embodiments, changes in functional
position are used to update the displayed anatomical data (e.g.,
indicating that the heart moved, based on movement of hot spots
thereof).
[0161] Reference 602 shows a signal as might be measured at 414. A
generally low amplitude and angularly wide peak indicates the
distance and spatial distribution of radiation emission
targets.
[0162] Reference 604 indicates a signal as may be measured at 416,
the dual peaks indicate that source 406 is to one side and sources
408-412 (not distinguished) are to another side. Based on the
previously acquired model of the NM data, this suggests guiding the
catheter to the left. If only a scalar signal is measured, it is
expected that the measured amplitude increase towards location 416
and then decrease as the catheter moves away (possible increasing
again when entering the organ).
[0163] In some exemplary embodiments of the invention, an expected
measured signal may be provided by analyzing the NM data (e.g.,
image) and simulating a travel of the catheter in that data. Such
an expected signal can be a 1D signal or a 2d or 3D or 4D signal
(with one dimension being time or location along the path).
Optionally or alternatively, signals expected if the catheter is
incorrectly navigated are also generated. Optionally, the system
can show to the user the expected signal and/or signal gradient.
Optionally or alternatively, the system can generate an alert if
the catheter deviates from such an expected signal, for example,
using processor 120.
[0164] Reference 606 indicates a signal as may be measured when
entering organ 404 and which shows peaks corresponding to each of
hot spots 408, 410 and 412. In an exemplary embodiment of the
invention, the relative angular position of the peaks is used to
determine catheter position. It may be expected that as catheter
200 advances to location 420, the peaks will move apart and
increase in intensity.
[0165] In one example, signal 606 is correlated to the NM data by
generating an array of signals as expected to be measured from
multiple locations in the body (e.g., locations along the path
and/or with organ 404). Correlation can then be used to find one or
more best and/or acceptable fits. Optionally or alternatively,
expected signals are generated (and/or refined and/or searched) on
the fly based on an expected and/or estimated position(s) or
range(s) of positions of the catheter. In some embodiments
correlation is statistical, in that different possibilities are
given a different probability of being possible, based on quality
of correlation and/or a model of noise in measurement and/or change
in emission relative to the acquired NM data. The determined
correlation may be used to select between multiple possible
positions and/or narrow down the position of the catheter.
[0166] In an exemplary embodiment of the invention, radiation-based
position is combined with other types of positioning. For example,
electrical impedance based positioning (or other positioning
methods) may be accurate with respect to the organ, but inaccurate
with respect to small movements of a catheter. However, if such
small movements have a significant effect on the radiation signal
(e.g., emitted from a hot spot), the two signals can be combined or
the radiation signal can be used to correct the impedance
signal.
[0167] Even if the position sensor is precise, if organ 404 moves
and/or deforms, the position relative to the organ may be less
precise. A functional position may be used to
correct/update/replace the signal.
[0168] In some embodiments of the invention, for example, if
correlation indicates multiple possible positions for the catheter,
processor 120 indicates a change in catheter position which should
result in a different signal depending on the starting point of the
catheter. If a user then moves the catheter, the resulting signal
may then be used to further select between alternative
approximations of the starting position.
[0169] Signal 608 shows a measurement at location 422, near hotspot
412. While there is a high peak, the secondary peaks are
incorrectly located.
[0170] Signal 610 shows a central high peak (410) and two smaller
side peaks (408, 412), smaller due to distance. Optionally, at this
point catheter 200 is moved to maximize the signal. Optionally,
image reconstruction, for example as described above, is applied to
better image the hot spot.
General
[0171] It is expected that during the life of a patent maturing
from this application many relevant nuclear medicine imaging
techniques will be developed and the scope of the term NM is
intended to include all such new technologies a priori. As used
herein the term "about" refers to .+-.10%.
[0172] The terms "comprises", "comprising", "includes",
"including", "having" and their conjugates mean "including but not
limited to".
[0173] The term "consisting of" means "including and limited
to".
[0174] The term "consisting essentially of" means that the
composition, method or structure may include additional
ingredients, steps and/or parts, but only if the additional
ingredients, steps and/or parts do not materially alter the basic
and novel characteristics of the claimed composition, method or
structure.
[0175] As used herein, the singular form "a", "an" and "the"
include plural references unless the context clearly dictates
otherwise. For example, the term "a compound" or "at least one
compound" may include a plurality of compounds, including mixtures
thereof.
[0176] Throughout this application, various embodiments of this
invention may be presented in a range format. It should be
understood that the description in range format is merely for
convenience and brevity and should not be construed as an
inflexible limitation on the scope of the invention. Accordingly,
the description of a range should be considered to have
specifically disclosed all the possible subranges as well as
individual numerical values within that range. For example,
description of a range such as from 1 to 6 should be considered to
have specifically disclosed subranges such as from 1 to 3, from 1
to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as
well as individual numbers within that range, for example, 1, 2, 3,
4, 5, and 6. This applies regardless of the breadth of the
range.
[0177] Whenever a numerical range is indicated herein, it is meant
to include any cited numeral (fractional or integral) within the
indicated range. The phrases "ranging/ranges between" a first
indicate number and a second indicate number and "ranging/ranges
from" a first indicate number "to" a second indicate number are
used herein interchangeably and are meant to include the first and
second indicated numbers and all the fractional and integral
numerals therebetween.
[0178] As used herein the term "method" refers to manners, means,
techniques and procedures for accomplishing a given task including,
but not limited to, those manners, means, techniques and procedures
either known to, or readily developed from known manners, means,
techniques and procedures by practitioners of the chemical,
pharmacological, biological, biochemical and medical arts.
[0179] As used herein, the term "treating" includes abrogating,
substantially inhibiting, slowing or reversing the progression of a
condition, substantially ameliorating clinical or aesthetical
symptoms of a condition or substantially preventing the appearance
of clinical or aesthetical symptoms of a condition.
[0180] It is appreciated that certain features of the invention,
which are, for clarity, described in the context of separate
embodiments, may also be provided in combination in a single
embodiment. Conversely, various features of the invention, which
are, for brevity, described in the context of a single embodiment,
may also be provided separately or in any suitable subcombination
or as suitable in any other described embodiment of the invention.
Certain features described in the context of various embodiments
are not to be considered essential features of those embodiments,
unless the embodiment is inoperative without those elements.
[0181] Although the invention has been described in conjunction
with specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims.
[0182] All publications, patents and patent applications mentioned
in this specification are herein incorporated in their entirety by
reference into the specification, to the same extent as if each
individual publication, patent or patent application was
specifically and individually indicated to be incorporated herein
by reference. In addition, citation or identification of any
reference in this application shall not be construed as an
admission that such reference is available as prior art to the
present invention. To the extent that section headings are used,
they should not be construed as necessarily limiting. In addition,
any priority document(s) of this application is/are hereby
incorporated herein by reference in its/their entirety.
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