U.S. patent application number 09/803977 was filed with the patent office on 2001-08-02 for system for translation of electromagnetic and optical localization systems.
This patent application is currently assigned to Medtronic Surgical Navigation Technologies. Invention is credited to Hunter, Mark W., Kessman, Paul.
Application Number | 20010011175 09/803977 |
Document ID | / |
Family ID | 23703800 |
Filed Date | 2001-08-02 |
United States Patent
Application |
20010011175 |
Kind Code |
A1 |
Hunter, Mark W. ; et
al. |
August 2, 2001 |
System for translation of electromagnetic and optical localization
systems
Abstract
A system for utilizing and registering at least two surgical
navigation systems during stereotactic surgery. The system
comprises a first surgical navigation system defining a first
patient space, a second surgical navigation system defining a
second patient space, and a translation device to register the
coordinates of the first patient space to the coordinates of the
second patient space. The translation device comprises a rigid
body, at least one component for a first navigation system placed
in or on the rigid body, and at least one component for a second
navigation system placed in or on the rigid body, in known relation
to the at least one component for the first navigation system. The
translation device is positioned in a working volume of each of the
at least two navigation systems.
Inventors: |
Hunter, Mark W.;
(Broomfield, CO) ; Kessman, Paul; (Broomfield,
CO) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT &
DUNNER LLP
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Assignee: |
Medtronic Surgical Navigation
Technologies
|
Family ID: |
23703800 |
Appl. No.: |
09/803977 |
Filed: |
March 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09803977 |
Mar 13, 2001 |
|
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|
09429568 |
Oct 28, 1999 |
|
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|
6235038 |
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Current U.S.
Class: |
606/130 |
Current CPC
Class: |
A61B 2090/0818 20160201;
A61B 2034/2055 20160201; A61B 2090/3995 20160201; A61B 2090/3983
20160201; A61B 2034/2072 20160201; A61B 2034/2051 20160201; A61B
2090/364 20160201; A61B 34/20 20160201; A61B 90/36 20160201; A61B
90/10 20160201 |
Class at
Publication: |
606/130 |
International
Class: |
A61B 019/00 |
Claims
What is claimed is:
1. A system for utilizing and registering at least two surgical
navigation systems during stereotactic surgery, the system
comprising: a first surgical navigation system defining a first
patient space; a second surgical navigation system defining a
second patient space; and a translation device to register the
coordinates of the first patient space to the coordinates of the
second patient space.
2. The system of claim 1, wherein the first navigation system is a
line-of-sight navigation system.
3. The system of claim 2, wherein the line-of-sight navigation
system is an optical navigation system.
4. The system of claim 2, wherein the second navigation system is a
non-line-of-sight navigation system.
5. The system of claim 4, wherein the non-line-of sight system is
an electromagnetic navigation system.
6. The system of claim 1, wherein the translation device includes
at least one component for the first navigation system and at least
one component for the second navigation system.
7. The system of claim 6, wherein the translation matrix between
the at least one component for the first navigation system and the
at least one component of the second navigation system is
predetermined.
8. The system of claim 7, wherein the first navigation system is an
optical navigation system and the at least one components for the
first navigation system is an optical element.
9. The system of claim 8, wherein the second navigation system is
an electromagnetic navigation system and the at least one component
for the second navigation system is an electromagnetic element.
10. The system of claim 9, wherein the at least one electromagnetic
element is a sensor.
11. A device for registering coordinates of at least two navigation
systems, the device comprising: a rigid body; at least one
component for a first navigation system placed in or on the rigid
body; and at least one component for a second navigation system
placed in or on the rigid body, in known relation to the at least
one component for the first navigation system, wherein the device
is positioned in a working volume of each of the at least two
navigation systems.
12. The device of claim 11, wherein the first navigation system is
a line-of line-of-sight navigation system.
13. The system of claim 12, wherein the line-of-sight navigation
system is an optical navigation system.
14. The system of claim 12, wherein the second navigation system is
a non-line-of-sight navigation system.
15. The system of claim 14, wherein the non-line-of sight system is
an electromagnetic navigation system.
16. The system of claim 11, wherein the first navigation system is
an optical navigation system and the at least one component for the
first navigation system is an optical element.
18. The system of claim 16, wherein the second navigation system is
an electromagnetic navigation system and the at least one component
for the second navigation system is an electromagnetic element.
19. The system of claim 9, wherein the electromagnetic element is a
sensor.
20. The system of claim 9, wherein the electromagnetic element
generates an electromagnetic field.
Description
CONCURRENTLY FILED APPLICATIONS
[0001] The following United States patent applications, which were
concurrently filed with this one on Oct. 28, 1999, are fully
incorporated herein by reference: Method and System for Navigating
a Catheter Probe in the Presence of Field-influencing Objects, by
Michael Martinelli, Paul Kessman and Brad Jascob; Patient-shielding
and Coil System, by Michael Martinelli, Paul Kessman and Brad
Jascob; Navigation Information Overlay onto Ultrasound Imagery, by
Paul Kessman, Troy Holsing and Jason Trobaugh; Coil Structures and
Methods for Generating Magnetic Fields, by Brad Jascob, Paul
Kessman and Michael Martinelli; Registration of Human Anatomy
Integrated for Electromagnetic Localization, by Mark W. Hunter and
Paul Kessman; System for Translation of Electromagnetic and Optical
Localization Systems, by Mark W. Hunter and Paul Kessman; Surgical
Communication and Power System, by Mark W. Hunter, Paul Kessman and
Brad Jascob; and Surgical Sensor, by Mark W. Hunter, Sheri McCoid
and Paul Kessman.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to localization of a position
during surgery. The present invention relates more specifically to
a system that facilitates combined electromagnetic and optical
localization of a position during stereotactic surgery, such as
brain surgery and spinal surgery.
[0004] 2. Description of Related Art
[0005] Precise localization of a position has always been important
to stereotactic surgery. In addition, minimizing invasiveness of
surgery is important to reduce health risks for a patient.
Stereotactic surgery minimizes invasiveness of surgical procedures
by allowing a device to be guided through tissue that has been
localized by preoperative scanning techniques, such as for example,
MR, CT, ultrasound, fluoro and PET. Recent developments in
stereotactic surgery have increased localization precision and
helped minimize invasiveness of surgery.
[0006] Stereotactic surgery is now commonly used in surgery of the
brain. Such methods typically involve acquiring image data by
placing fiducial markers on the patient's head, scanning the
patient's head, attaching a headring to the patient's head, and
determining the spatial relation of the image data to the headring
by, for example, registration of the fiducial markers. Registration
of the fiducial markers relates the information in the scanned
image data for the patient's brain to the brain itself, and
utilizes one-to-one mapping between the fiducial markers as
identified in the image data and the fiducial markers that remain
on the patient's head after scanning and throughout surgery. This
is referred to as registering image space to patient space. Often,
the image space must also be registered to another image space.
Registration is accomplished through knowledge of the coordinate
vectors of at least three non-collinear points in the image space
and the patient space.
[0007] Currently, registration for image guided surgery is
completed by a few different methods. First, point-to-point
registration is accomplished by the user to identify points in
image space and then touch the same points in patient space.
Second, surface registration involves the user's generation of a
surface (e.g., the patient's forehead) in patient space by either
selecting multiple points or scanning, and then accepting or
rejecting the best fit to that surface in image space, as chosen by
the processor. Third, repeat fixation devices entail the user
repeatedly removing and replacing a device in known relation to the
fiducial markers. Such registration methods have additional steps
during the procedure, and therefore increase the complexity of the
system and increase opportunities for introduction of human
error.
[0008] Through the image data, quantitative coordinates of targets
within the patient's body can be specified relative to the fiducial
markers. Once a guide probe or other instrument has been registered
to the fiducial markers on the patient's body, the instrument can
be navigated through the patient's body using image data.
[0009] It is also known to display large, three-dimensional data
sets of image data in an operating room or in the direct field of
view of a surgical microscope. Accordingly, a graphical
representation of instrument navigation through the patient's body
is displayed on a computer screen based on reconstructed images of
scanned image data.
[0010] Although scanners provide valuable information for
stereotactic surgery, improved accuracy in defining the position of
the target with respect to an accessible reference location can be
desirable. Inaccuracies in defining the target position create
inaccuracies in placing a therapeutic probe. One method for
attempting to limit inaccuracies in defining the target position
involves fixing the patient's head to the scanner to preserve the
reference. Such fixation may be uncomfortable for the patient and
creates other inconveniences, particularly if surgical procedures
are involved. Consequently, a need exists for a system utilizing a
scanner to accurately locate positions of targets, which allows the
patient to be removed from the scanner.
[0011] Stereotactic surgery utilizing a three-dimensional digitizer
allows a patient to be removed from the scanner while still
maintaining a high degree of accuracy for locating the position of
targets. The three-dimensional digitizer is used as a localizer to
determine the intra-procedural relative positions of the target.
Three-dimensional digitizers may employ optical, acoustic,
electromagnetic or other three-dimensional navigation technology
for navigation through the patient space.
[0012] Different navigational systems have different advantages and
disadvantages. For example, electromagnetic navigation systems do
not require line-of-sight between the tracking system components.
Thus, electromagnetic navigation is beneficial for laproscopic and
percutaneous procedures where the part of the instrument tracked
cannot be kept in the line-of sight of the other navigation system
components. Since electromagnetic navigation allows a tracking
element to be placed at the tip of an instrument, electromagnetic
navigation allows the use of non-rigid instruments such as flexible
endoscopes. However, use of certain materials in procedures
employing electromagnetic tracking is disadvantageous since certain
materials could affect the electromagnetic fields used for
navigation and therefore affect system accuracy.
[0013] Comparatively, optical navigation systems have a larger
working volume than electromagnetic navigation systems, and can be
used with instruments having any material composition. However, the
nature of optical navigation systems does not accommodate tracking
system components on any portion of an instrument to be inserted
into the patient's body. For percutaneous and laproscopic
procedures, optical navigation systems typically track portions of
the system components that are in the system's line of sight, and
then determine the position of any non-visible portions of those
components based on system parameters. For example, an optical
navigation system can track the handle of a surgical instrument but
not the inserted tip of the surgical instrument, thus the
navigation system must track the instrument handle and use
predetermined measurements of the device to determine where the tip
of the instrument is relative to the handle. This technique cannot
be used for flexible instruments since the relation between the
handle and the tip varies.
[0014] Stereotactic surgery techniques are also utilized for spinal
surgery, in order to increase accuracy of the surgery and minimize
invasiveness. Accuracy is particularly difficult in spinal surgery
and must be accommodated in registration and localization
techniques utilized in the surgery. Prior to spinal surgery, the
vertebra are scanned to determine their alignment and positioning.
During imaging, scans are taken at intervals through the vertebra
to create a three-dimensional pre-procedural data set for the
vertebra. However, after scanning the patient must be moved to the
operating table, causing repositioning of the vertebra. In
addition, the respective positions of the vertebra may shift once
the patient has been immobilized on the operating table because,
unlike the brain, the spine is not held relatively still by a
skull-like enveloping structure. Even normal patient respiration
may cause relative movement of the vertebra.
[0015] Computer processes discriminate the image data retrieved by
scanning the spine so that the body vertebra remain in memory. Once
the vertebra are each defined as a single rigid body, the vertebra
can be repositioned with software algorithms that define a
displaced image data set. Each rigid body element has at least
three fiducial markers that are visible on the pre-procedural
images and accurately detectable during the procedure. It is
preferable to select reference points on the spinous process that
are routinely exposed during such surgery.
[0016] See also, for example, U.S. Pat. No. 5,871,445, WO 96/11624,
U.S. Pat. No. 5,592,939 and U.S. Pat. No. 5,697,377, the
disclosures of which are incorporated herein by reference.
SUMMARY OF THE INVENTION
[0017] To enhance the prior art, and in accordance with the
purposes of the invention, as embodied and broadly described
herein, there is provided a system for utilizing and registering at
least two surgical navigation systems during stereotactic surgery.
The system comprises a first surgical navigation system defining a
first patient space, a second surgical navigation system defining a
second patient space, and a translation device to register the
coordinates of the first patient space to the coordinates of the
second patient space. The translation device comprises a rigid
body, at least one component for a first navigation system placed
in or on the rigid body, and at least one component for a second
navigation system placed in or on the rigid body, in known relation
to the at least one component for the first navigation system. The
translation device is positioned in a working volume of each of the
at least two navigation systems.
[0018] Additional features and advantages of the invention will be
set forth in the description which follows, and in part will be
apparent from the description, or may be learned from practice of
the invention. The objectives and other advantages of the invention
will be realized and attained by the apparatus particularly pointed
out in the written description and claims herein as well as the
appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings, which are incorporated in and
constitute part of the specification, illustrate a presently
preferred embodiment of the invention and together with the general
description given above and detailed description of the preferred
embodiment given below, serve to explain the principles of the
invention.
[0020] FIG. 1 is a schematic diagram illustrating an embodiment of
the system that facilitates combined electromagnetic and optical
localization of a position during stereotactic surgery according to
the present invention;
[0021] FIG. 2 illustrates a top view of a first embodiment of an
optical-to-electromagnetic translation device;
[0022] FIG. 3 illustrates a schematic perspective view of a second
embodiment of an optical-to-electromagnetic translation device;
[0023] FIG. 4 illustrates a schematic perspective view of a third
embodiment of an optical-to-electromagnetic translation device;
and
[0024] FIG. 5 illustrates a schematic perspective view of a fourth
embodiment of an optical-to-electromagnetic translation device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Reference will now be made in detail to the present
preferred exemplary embodiments of the invention, examples of which
are illustrated in the accompanying drawings. Wherever possible,
the same reference numbers will be used throughout the drawings to
refer to the same or like parts.
[0026] The present invention contemplates a system for stereotactic
surgery comprising a first surgical navigation system defining a
first patient space, a second surgical navigation system defining a
second patient space, a translation device to register (correlate
the coordinates of) the first patient space to the second patient
space, and an image data set generated from a scanning device that
defines an image space. The image space is registered to at least
one of the first and second patient spaces.
[0027] An exemplary embodiment of the system 10 of the present
invention is illustrated in FIG. 1. The system of the present
invention will be discussed hereinafter with respect to a an
optical navigation system in combination with an electromagnetic
navigation system. However, the present invention similarly
contemplates combining any two navigation systems including
optical, acoustic, electromagnetic, or conductive.
[0028] The system illustrated in FIG. 1 includes a first navigation
system that is optical. Elements of the optical navigation system
include at least one optical element, and an optical receiving
array 40 in line-of-sight communication with the optical element
and in communication with a computer system 50. The optical element
can either generate an optical signal independently or
alternatively generate an optical signal by reflecting a signal
received from an optical signal source. The line-of-sight of the
optical receiving array defines a "working volume" of the optical
system, which is the space in which the optical system can
effectively navigate.
[0029] At least one optical element is placed on a translation
device. According to the illustrated embodiment of the present
invention, preferably at least three non-collinear optical elements
are utilized by the system in order to obtain six degrees of
freedom location and orientation information from the optical
elements.
[0030] In the exemplary embodiment of the invention illustrated in
FIG. 1, four embodiments of the translation device 20, 60, 80, 100
are shown in the working volume of the optical system. While only
one translation device is needed for proper operation of the
translation system of the present invention, the present invention
also contemplates the use of more than one translation device for
registration of different navigation systems. For example, more
than one translation device could be used for redundant
registration of two navigation systems in order to obtain increased
accuracy of registration. In addition, if three different
navigation systems were utilized in a single surgical procedure,
one translation device could be used to register (i.e., correlate
the coordinates of) all three navigation systems, or one
translation device could be used to register the first and second
navigation systems while another translation device registered the
second and third navigation systems.
[0031] As illustrated in FIGS. 1 and 2, a dynamic translation
device can be incorporated into a medical instrument 60 for use in
the surgical procedure being navigated. The medical instrument 60
includes a handle 62, a tip portion 64 and a localization frame 66.
At least three collinear optical elements 70 (capable of defining
six degrees of freedom in the optical system) are placed on the
localization frame for communication with the optical receiving
array 40. As the medical instrument moves in the working volume of
the optical system, the optical receiving array 40 sends a signal
to the computer system 50 indicating the current position of the
medical instrument 60.
[0032] As illustrated in FIGS. 1 and 3, a translation device can
also be incorporated into a rigid static translation device 100
that is added to the optical and electromagnetic navigation system
working spaces specifically to register (i.e., correlate the
coordinates of) the optical navigation system to the
electromagnetic navigation system. The static translation device
may have any configuration allowing optical elements 110 to be
placed in such a manner to define six degrees of freedom in the
optical system (e.g., three non-collinear optical elements).
Although this embodiment provides a suitable translation device, it
also adds undesirable complexity to the navigation systems by
requiring the navigation systems to receive input from and identify
an additional structure in their working volume.
[0033] As illustrated in FIGS. 1 and 4, a translation device can
also be incorporated into the operating table. Optical elements 85
defining six degrees of freedom in the optical system are placed on
the operating table in such a manner that they will remain in the
line-of-sight of the optical receiving array 40 during the
procedure.
[0034] As illustrated in FIGS. 1 and 5, a dynamic translation
device can further be incorporated into one or more of the optical
elements 20 placed on the patient 30 (or mounted to the patient via
a frame).
[0035] It is to be understood that optical elements 20, 70 may be
placed on the patient 30 or on the medical instrument 60 for
tracking movement of the patient 30 and/or the medical instrument
60 during the procedure, even if the optical elements 20, 70 on the
patient 30 and the medical instrument 60 are not used as
translation devices.
[0036] As illustrated in FIG. 1, the system of the present
invention also includes a second navigation system. In the
embodiment illustrated in FIG. 1, the second navigation system is
electromagnetic. Thus, any translation device also has at least one
component for the electromagnetic navigation system that is in
known relationship to the optical elements placed on the device.
The known relation of the optical and electromagnetic elements is
received by the computer system 50 so that the computer system can
generate a translation matrix for registration (i.e., correlation
of the coordinates) of the optical and electromagnetic navigation
systems. Elements of the illustrated electromagnetic navigation
system include an electromagnetic element 90 (e.g., a sensor having
at least one coil 92), and a magnetic field generator. In the
embodiment shown in FIG. 1, the magnetic field generator is
provided in the operating table 80. Therefore, in the embodiment of
the translation device shown in FIG. 4, as described above, the
magnetic field generator in the operating table 80 serves as the
electromagnetic element on the translation device when placed in
known relation to the optical elements 85 placed on the table 80.
The known relation of the optical and electromagnetic elements is
received by the computer system 50 so that the computer system can
generate a translation matrix for correlation of the optical and
electromagnetic navigation system coordinates.
[0037] In the medical instrument 60 embodiment of the translation
device illustrated in FIG. 2, the electromagnetic element 90 is
preferably a sensor having at least one coil 92. The sensor
includes two coils 92 that are placed perpendicular to each other
to create a sensor having six degrees of freedom. The sensor is
placed in or on the localization frame 66 in known relation to the
optical elements 70. The known relation of the optical and
electromagnetic elements is received by the computer system 50 so
that the computer system can generate a translation matrix for
correlation of the optical and electromagnetic navigation system
coordinates.
[0038] In the rigid static embodiment 100 of the translation device
illustrated in FIG. 3, the electromagnetic element 90 is preferably
a sensor as described above with respect to FIG. 2, placed in or on
the rigid static device 100 in known relation to the optical
elements 110. The known relation of the optical and electromagnetic
elements is received by the computer system 50 so that the computer
system can generate a translation matrix for correlation of the
optical and electromagnetic navigation system coordinates.
[0039] As illustrated in FIG. 5, showing a schematic version of a
dynamic translation device to be integrated one or more of the
optical elements 20 placed on the patient 30 (or mounted to the i
patient via a frame), the electromagnetic element 90 is preferably
a sensor as described above with respect to FIG. 2. The sensor is
preferably placed in or on the base 25 in known relation to the
optical element 20. The known relation of the optical and
electromagnetic elements is received by the computer system 50 so
that the computer system can generate a translation matrix for
correlation of the optical and electromagnetic navigation system
coordinates. Although the embodiment of FIG. 5 shows the
electromagnetic element being integrated with the optical element,
the electromagnetic element may alternatively be attached to or
interchanged with the optical element 20 placed on the patient 30
(or mounted to the patient via a frame).
[0040] It is to be understood that an electromagnetic element 90
may be placed on the patient 30 or on the medical instrument 60 for
tracking movement of the patient 30 and or the medical instrument
60 during the procedure, even if the electromagnetic element 90 on
the patient 30 and the medical instrument 60 is not used as
translation devices.
[0041] An exemplary operation of the system of the present
invention will now be described. For the purposes of the example,
the procedure is brain surgery and the translation device is only
included in the medical instrument 60, as illustrated in FIG. 2. An
optical navigation system and an electromagnetic navigation system
are used.
[0042] Prior to the surgical procedure, fiducial markers are placed
on the patient's head and the patient's head is scanned using, for
example, a MR, CT, ultrasound, fluoro or PET scanner. The scanner
generates an image data set including data points corresponding to
the fiducial markers.
[0043] The image data set is received and stored by the computer
system.
[0044] After the patient's head has been scanned, the patient is
placed on the operating table and the navigation systems are turned
on. In brain surgery, the navigation systems track movement of the
patients head and movement of the medical instrument. Since the
medical instrument is used as the translation device, both optical
and electromagnetic navigation system elements are placed on the
medical instrument and both the optical and electromagnetic systems
track movement of the medical instrument.
[0045] Since the patient's head must also be tracked, either
optical or electromagnetic navigation system elements must be
placed on the patient's head. For the purposes of the present
illustration, optical elements are placed on the patient's head.
Since the optical navigation system is tracking movement of the
patient's head, the optical navigation system's patient space must
be registered to the image space defined by the pre-operative
scan.
[0046] After the optical navigation system patient space has been
registered to the image space, the electromagnetic navigation
system patient space must be registered to the optical navigation
system patient space. Having a known relation between the
electromagnetic and optical elements in the medical instrument
allows the computer to use a translation matrix to register the
optical navigation system patient space to the electromagnetic
navigation system patient space. Thus, the electromagnetic
navigation patient space is registered to the image space.
[0047] If the medical instrument has a rigid design, knowing the
dimensions of the medical instrument and the orientation and
location of the localization frame 66 allows the computer system to
determine the position of the tip of the medical instrument.
However, in the case where the medical instrument 60 has a
non-rigid design, merely knowing the location and orientation of
the localization frame 66 by tracking the position of the optical
and electromagnetic elements cannot allow the computer to determine
the position of the tip 64 of the medical instrument. Additionally,
optical navigation systems are line-of-sight navigation systems and
therefore do not allow direct tracking of the tip of a probe once
it has been inserted into the patient (because the tip is out of
the line-of sight of the optical receiving array).
[0048] However, electromagnetic navigation systems do not require
line-of-sight and therefore can track the location and orientation
of the inserted tip of even a non-rigid medical instrument. To do
so, an electromagnetic element 90 is placed in the tip portion 64
of the medical instrument and is tracked by the electromagnetic
navigation system. Since the electromagnetic navigation system
patient space has been registered to the image space, movement of
the tip of the medical instrument within the patient's brain
(within the image space) can be tracked.
[0049] Thus, the present invention allows increased accuracy and
flexibility for users by utilizing the features of multiple
navigation system to their respective advantages. In addition,
utilizing multiple navigation systems often increases the overall
working volume during the procedure.
[0050] It will be apparent to those skilled in the art that various
modifications and variations can be made to the system of the
present invention without departing from the scope or spirit of the
invention. Thus, it is intended that the present invention cover
the modifications and variations of this invention provided they
come within the scope of the appended claims and their
equivalents.
* * * * *