U.S. patent application number 14/315021 was filed with the patent office on 2015-01-01 for robotic image control system.
The applicant listed for this patent is Corindus, Inc.. Invention is credited to Per Bergman, Steven J. Blacker, Robert Elden, Jerry Jennings, Nicholas Kottenstette, Jean-Pierre Schott, Christopher Zirps.
Application Number | 20150005865 14/315021 |
Document ID | / |
Family ID | 52116262 |
Filed Date | 2015-01-01 |
United States Patent
Application |
20150005865 |
Kind Code |
A1 |
Bergman; Per ; et
al. |
January 1, 2015 |
ROBOTIC IMAGE CONTROL SYSTEM
Abstract
This disclosure involves the use of X-ray markers that appear in
fluoroscopic images and are detected by image processing software
to partially or fully automate or assist in the performance of one
or more of the steps of a percutaneous interventional procedure
typically involving a catheter device.
Inventors: |
Bergman; Per; (West Roxbury,
MA) ; Blacker; Steven J.; (Framingham, MA) ;
Elden; Robert; (Cambridge, MA) ; Jennings; Jerry;
(Chelsea, MA) ; Kottenstette; Nicholas;
(Worcester, MA) ; Schott; Jean-Pierre; (Weston,
MA) ; Zirps; Christopher; (Sharon, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Corindus, Inc. |
Waltham |
MA |
US |
|
|
Family ID: |
52116262 |
Appl. No.: |
14/315021 |
Filed: |
June 25, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61839459 |
Jun 26, 2013 |
|
|
|
Current U.S.
Class: |
623/1.11 ;
600/424; 606/194 |
Current CPC
Class: |
A61B 2090/061 20160201;
A61B 2017/00075 20130101; A61B 6/504 20130101; A61B 2018/00386
20130101; A61B 2034/107 20160201; A61M 2025/09166 20130101; A61B
2034/2065 20160201; A61M 25/104 20130101; A61B 34/20 20160201; A61B
6/12 20130101; A61M 2025/0166 20130101; A61B 2017/22042 20130101;
A61B 2018/00375 20130101; A61B 2090/3966 20160201; A61B 2090/376
20160201; A61F 2/958 20130101; A61B 2034/301 20160201; A61B 6/487
20130101; A61M 25/09041 20130101; A61B 6/485 20130101; A61M 25/0108
20130101; A61M 25/0113 20130101 |
Class at
Publication: |
623/1.11 ;
606/194; 600/424 |
International
Class: |
A61B 6/12 20060101
A61B006/12; A61F 2/958 20060101 A61F002/958; A61B 6/00 20060101
A61B006/00; A61M 25/10 20060101 A61M025/10 |
Claims
1. A process for mapping the three dimensional configuration of a
blood vessel of a human subject comprising: providing an elongated
percutaneous device; providing a system for measuring advancement
and retraction of the elongated percutaneous device; providing a
fluoroscopic imaging system which provides a two dimensional image
of a portion of the elongated percutaneous device in the blood
vessel; advancing or retracting the elongated percutaneous device
within the blood vessel; obtaining a first fluoroscopic image when
the portion of the elongated percutaneous device is at a first
location within the blood vessel and a second fluoroscopic image
when the portion of the elongated percutaneous device is at a
second location within the blood vessel; measuring a first distance
that the elongated percutaneous device has advanced or retracted
when the first fluoroscopic image is taken; measuring a second
distance that the elongated percutaneous device has advanced or
retracted between the first fluoroscopic image and the second
fluoroscopic image; correlating the fluoroscopic images with the
distance measurements to provide an indication of the travel of the
elongated percutaneous device out of the plane of the fluoroscopic
image.
2. The process of claim 1 wherein the blood vessel is an
artery.
3. The process of claim 2 wherein a general map of the artery
system of which the blood vessel is part is used to aid in the
correlation.
4. The process of claim 2 wherein anatomical observation is used to
aid in the correlation.
5. The process of claim 1 wherein the elongated percutaneous device
is a robotically driven guide wire with an X-ray marker located at
its tip which has been advanced out of the distal end of a guide
catheter which is positioned in the heart of the subject.
6. The process of claim 1 wherein the elongated percutaneous device
is a guide wire with an X-ray marker located at its tip.
7. The process of claim 6 wherein a second set of fluoroscopic
images of the X-ray marker of the guide wire taken in a plane
orthogonal to the plane of the first set of fluoroscopic images is
used to aid in the correlation.
8. The process of claim 6 wherein a fluoroscopic image is taken
each time a predetermined length of guide wire is advanced into the
guide catheter.
9. The process of claim 1 wherein a fluoroscopic image is taken at
predetermined time intervals and a length measurement is made at
the same time.
10. The process of claim 1 wherein the length measurement is taken
after removing any slack in the elongated percutaneous device.
11. The process of claim 10 wherein the slack is removed by first
advancing the elongated percutaneous device into the blood vessel
and then partially withdrawing it.
12. The process of claim 1 wherein the three dimensional mapping is
used to aid in the placement of a working catheter.
13. The process of claim 12 wherein the working catheter is being
placed to deliver an interventional device to a lesion in the blood
vessel.
14. The process of claim 13 wherein the device is one or more
balloons or a stent.
15. A process to optimize the plane of a fluoroscopic image used to
monitor a percutaneous interventional procedure on a human subject
involving a blood vessel comprising: providing an elongated
percutaneous device; providing a system for measuring advancement
and retraction of the elongated percutaneous device; providing a
fluoroscopic imaging system which provides a two dimensional image
of a portion of the elongated percutaneous device in the blood
vessel; advancing the elongated percutaneous device into or
retracting the elongated percutaneous device out of the blood
vessel; obtaining a first fluoroscopic image when the portion of
the elongated percutaneous device is at a first location within the
blood vessel and a second fluoroscopic image when the portion of
the elongated percutaneous device is at a second location within
the blood vessel; measuring a first distance that the elongated
percutaneous device has advanced or retracted when the first
fluoroscopic image is taken; measuring a second distance that the
elongated percutaneous device has advanced or retracted between the
first fluoroscopic image and the second fluoroscopic image;
correlating the fluoroscopic images with the length measurements to
provide an indication of the travel of the elongated percutaneous
device out of the plane of the fluoroscopic image; and adjusting
the plane of the fluoroscopic image to minimize the amount of
travel of the elongated percutaneous device out of the plane of the
fluoroscopic image.
16. The process of claim 15 wherein the elongated percutaneous
device is a robotically driven guide wire with an X-ray marker
located at its tip which has been advanced out of the distal end of
a guide catheter which is positioned in the heart of the
subject.
17. The process of claim 15 wherein a fluoroscopic image is taken
either each time a predetermined length of the elongated
percutaneous device is advanced into or retracted from the blood
vessel or at predetermined time intervals and a length measurement
is made at the same time.
18. An apparatus for mapping the three dimensional configuration of
a blood vessel of a human subject comprising: a guide catheter
configured to have its distal end positioned at the ostium of a
blood vessel; a fluoroscopic imaging system which provides a two
dimensional image of the blood vessel; a robotically driven guide
wire carrying an X-ray marker; a measuring mechanism which reports
the distance the guide wire has been advanced into the guide
catheter; and a control mechanism which captures fluoroscopic
images of the X-ray marker of the guide wire when the X-ray marker
is at various distances from the distal end of the guide catheter
and correlates them to the distances that the guide wire has been
advanced into the guide catheter.
19. The apparatus of claim 18 wherein the blood vessel is an artery
and the distal end of the guide catheter is positioned in the heart
of the subject.
20. The apparatus of claim 18 wherein the control mechanism causes
a fluoroscopic image to be taken either each time a predetermined
length of guide wire is advanced into the guide catheter or at
predetermined time intervals and causes a length measurement to be
made at the same time.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application No. 61/839,459 entitled Robotic Image Control System
filed on Jun. 26, 2013 which is incorporated herein by reference in
its entirety.
BACKGROUND OF THE INVENTION
[0002] Systems exist for the robotic feeding of percutaneous
interventional devices such as guide wires and working catheters
into guide catheters and procedures exist for the placement and
seating of guide catheters such that their distal ends are adjacent
the site of action for the intervention, typically a valve or
chamber of the heart or a lesion in a blood vessel such as an
artery. The guide catheter is typically placed by manual
manipulation of medical personnel and its continued seating after
placement assumed or determined by feel. The interventional devices
such as guide wires and working catheters may be fed by the
operation of robotic controls by medical personnel such as shown in
U.S. Pat. No. 7,887,549.
SUMMARY OF THE INVENTION
[0003] The present invention involves the use of X-ray markers that
appear in fluoroscopic images and are detected by image processing
software to partially or fully automate or assist in the
performance of one or more of the steps of a percutaneous
interventional procedure typically involving a guide catheter.
[0004] The present invention also involves a process for mapping
the three dimensional configuration of a blood vessel of a human
subject by providing an elongated percutaneous device, a system for
measuring advancement and retraction of the elongated percutaneous
device and a fluoroscopic imaging system which provides a two
dimensional image of a portion of the elongated percutaneous device
in the blood vessel. A first fluoroscopic image is obtained when
the portion of the elongated percutaneous device is at a first
location within the blood vessel and a second fluoroscopic image is
obtained when the portion of the elongated percutaneous device is
at a second location within the blood vessel. A measurement is made
of a first distance that the elongated percutaneous device has
advanced or retracted when the first fluoroscopic image is taken
and a measurement is made of a second distance that the elongated
percutaneous device has advanced or retracted between the first
fluoroscopic image and the second fluoroscopic image. The
fluoroscopic images are correlated with the distance measurements
to provide an indication of the travel of the elongated
percutaneous device out of the plane of the fluoroscopic image.
[0005] The present invention further involves a process to optimize
the plane of a fluoroscopic image used to monitor a percutaneous
interventional procedure on a human subject involving a blood
vessel by providing an elongated percutaneous device, a system for
measuring advancement and retraction of the elongated percutaneous
device and a fluoroscopic imaging system which provides a two
dimensional image of a portion of the elongated percutaneous device
in the blood vessel. The elongated percutaneous device is advanced
into or retracted out of the blood vessel and a first fluoroscopic
image is obtained when the portion of the elongated percutaneous
device is at a first location within the blood vessel and a second
fluoroscopic image is obtained when the portion of the elongated
percutaneous device is at a second location within the blood
vessel. A first distance that the elongated percutaneous device has
advanced or retracted is measured when the first fluoroscopic image
is taken and a second distance that the elongated percutaneous
device has advanced or retracted between the first fluoroscopic
image and the second fluoroscopic image is measured. The
fluoroscopic images are correlated with the length measurements to
provide an indication of the travel of the elongated percutaneous
device out of the plane of the fluoroscopic image and the plane of
the fluoroscopic image is adjusted to minimize the amount of travel
of the elongated percutaneous device out of the plane of the
fluoroscopic image.
[0006] The present invention additionally involves apparatus for
mapping the three dimensional configuration of a blood vessel of a
human subject which comprises a guide catheter configured to have
its distal end positioned at the ostium of a blood vessel, a
fluoroscopic imaging system which provides a two dimensional image
of the blood vessel, a robotically driven guide wire carrying an
X-ray marker, a measuring mechanism which reports the distance the
guide wire has been advanced into the guide catheter, and a control
mechanism which captures fluoroscopic images of the X-ray marker of
the guide wire when the X-ray marker is at various distances from
the distal end of the guide catheter and correlates them to the
distances that the guide wire has been advanced into the guide
catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] This application will become more fully understood from the
following detailed description, taken in conjunction with the
accompanying figures, wherein like reference numerals refer to like
elements in which:
[0008] FIG. 1 is a schematic of the environment in which
percutaneous interventional procedures are robotically
performed.
[0009] FIG. 2 is a schematic of the placement of a guide catheter
and a guide wire in a human body.
[0010] FIG. 3 is a schematic of a guide wire carrying an X-ray
marker.
[0011] FIG. 4 is a schematic of a guide catheter carrying X-ray
markers.
[0012] FIG. 4 (a) and FIG. 4 (b) are schematics of various
configurations of X-ray markers on a guide catheter.
[0013] FIG. 5A-5H are schematics of a procedure of placing an
angioplasty balloon over a lesion using a guide catheter, a guide
wire, a working catheter and X-ray markers.
[0014] FIG. 6 is a schematic of a guide catheter in relationship to
the plane of a 2-D fluoroscopic image.
[0015] FIG. 7 is a flow diagram of creating a 3-D map of the path
of a guide wire being fed into a guide catheter.
[0016] FIG. 8 is a flow diagram of the automated feeding of a guide
wire into a guide catheter.
[0017] FIG. 9 is a flow diagram of the automated feeding of a guide
wire into a guide catheter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Three Dimensional Roadmap
[0018] An embodiment involves mapping the path to be followed in
deploying a percutaneous intervention device at its site of action.
One approach involves deploying a guide catheter in the
conventional manner, i.e. manually, and then feeding a guide wire
through the guide catheter and measuring its apparent travel path
in two-dimensional fluoroscopic images. This may be combined with
measurements about the length of guide wire fed into the guide
catheter and a general map of the artery system in which the guide
catheter is deployed to render a three dimensional map of the path
which includes travel in the z direction relative to the two
dimensional fluoroscopic images.
[0019] A three dimensional relative height map of the artery system
is built iteratively by comparing the length of the guide wire fed
into the catheter guide to the measurement of the 2D motion of the
distal end of the guide wire in the fluoroscopic image between two
successive positions. The map can be sampled at a given incremental
fixed length of guide wire by acquiring a fluoroscopic image every
time a fixed length of wire is inserted and measuring the 2D motion
of the wire along the path of the artery. Alternatively a
fluoroscopic image can be acquired at regular time interval and a
measurement of the length of the wire inserted and the 2D motion
the wire along the path of the artery acquired. The measurement of
the length of wire fed into the guide catheter and the measured
path of the wire along the artery produce a relative height
measurement between the initial and final position of the wire by
using simple foreshortening geometry. This method only determines
the magnitude of the differential height. The polarity of the
displacement (up or down) must be inferred by anatomical
observation of the arteries or by acquiring a second orthogonal
fluoroscopic with a two plane system,
[0020] The measurement of the 2D motion of the wire in the artery
can be facilitated by insertion of an easily detected fluoroscopic
marker on the guide wire. The marker position can be easily be
detecting by image processing of the fluoroscopic image.
[0021] An embodiment involves providing additional markers to
determine the height at multiple positions along the guide wire or
working catheter being fed into a guide catheter. The additional
markers may be on the guide wire or working catheter being fed or
both. Multiple, concurrent height measurements can be achieved
along the guide wire or working catheter by simultaneously
detecting all the makers and measuring their 2D motion
individually. The marker positions can be easily be detecting by
image processing of the fluoroscopic image or a plurality of
fluoroscopic images.
[0022] One of the markers may be inserted at the tip of the
wire.
[0023] The height map can be updated iteratively every time a guide
wire is inserted or any other wire containing marker is inserted
into the guide catheter. By changing the sampling time of the
fluoroscopic images or the length or rate of insertion of the wire
into the catheter guide, the measurement of the height will occur
at different locations along the arteries and will fill up the
height map.
[0024] The accuracy of the height map can be improved by estimating
the 2D location of the markers more accurately. The successive 2D
fluoroscopic images can be registered to each other by estimating
the global 2D motion of each image with respect to a reference
image. The estimation of the overall motion is represented by a
unique 2D translation vector. The estimation of the overall motion
is additionally represented by a unique 2D rotation angle. Once the
2D images are globally aligned, a secondary local alignment close
to the marker can be performed for additional accuracy. The global
and local alignment can be performed by normalized correlation of
the current image and reference image or images or two other images
to be aligned. The global and local alignment can be performed
using the generalized Hough transform of the current image and
reference image or images to be aligned.
Automatic Loading of a Guide Catheter
[0025] An embodiment involves robotically advancing a guide wire or
working catheter (i.e. a catheter that carries a balloon, a stent
or both) through a guide catheter until it is close to the end of
the guide catheter adjacent to the site of action such as a blood
vessel lesion or a chamber or valve of the heart. The tip of the
guide wire or the distal end of the working catheter and the distal
end of the guide catheter may both be provided with a marker
visible in a fluoroscopic image.
[0026] An embodiment involves providing additional markers,
possibly distinctive, to better monitor the progress of the guide
wire or working catheter in the guide catheter. The additional
markers may be on the guide catheter or the guide wire or working
catheter being fed or both. Fluoroscopic images in which these
markers appear may be combined with information about the length of
guide wire or working catheter fed into the guide catheter to
estimate the position of the tip of the guide wire or the end of
the working catheter. The multiple markers on the guide catheter
may also be used to estimate the effective velocity of the guide
wire or working catheter as it is being fed through the guide
catheter and this effective velocity may take account of the travel
out of the plane of the fluoroscopic images.
[0027] The control mechanism of the drive feeding the guide wire or
working catheter into the guide catheter causes the feeding to
substantially slow or stop as the two markers approach each other.
One approach involves taking fluoroscopic images of the progress of
the guide wire or working catheter through the guide catheter and
using image processing software to estimate the distance between
the two markers. The feeding can then be slowed or stopped when the
distance falls below a preset value. The X-ray exposure of the
patient may be reduced by taking intermittent fluoroscopic images
and the frame rate may be selected in accordance with the velocity
of feeding of the guide wire or working catheter.
[0028] When multiple markers are used on either the guide wire or
working catheter and the guide catheter, redundant detection of set
of markers decreases the risk of overshooting the end of the guide
catheter by imposing a stop if a maker or a set of marker preceding
the last distal marker are not detected within a predefined length
of guide wire or working catheter.
[0029] The use of multiple markers increase the accuracy of the
velocity estimation by averaging multiple measurements individually
affected by variable foreshortening due to the out of fluoroscopic
plane wire incursion.
[0030] Additionally, accuracy of the velocity and tip position is
increase by the use of a precomputed 3D map of the arteries that
take into account foreshortening.
[0031] An embodiment involves providing proximal markers for
greater safety. One approach is to provide additional markers on
the guide catheter spaced proximally from its distal end and using
these markers to better assure the control of the emergence of the
guide wire or working catheter out of the distal end of the guide
catheter.
Maintenance of Guide Catheter Seating
[0032] An embodiment involves determining whether the distal end of
a guide catheter has become unseated after it was placed adjacent
to the site of action, such as an arterial lesion or a chamber or
valve of the heart, and taking corrective action to reseat it. In
some cases when a working catheter carrying a stent, a balloon or
both passes through a guide catheter toward its distal end seated
near the site of action, it causes the guide catheter to move in
the opposite direction causing the distal end to unseat. The
corrective action may involve applying pressure to the guide
catheter in the distal direction to cause it to reseat.
Monitoring to Determine if Guide Wire Well Seated
[0033] An embodiment involves monitoring the arterial pressure or
the ST wave or an electrocardiogram of the patient undergoing the
interventional procedure or observing the appearance of a cloud of
contrast agent. A change in one of the first two parameters may be
used as an indication that the guide catheter is becoming unseated.
The appearance of the third may also be used as an indication that
distal end of the guide catheter is not in its proper position when
contrast agent is being fed through the guide catheter.
[0034] The contrast agent may be detected by means of image
processing of the fluoroscopic images.
[0035] An embodiment involves comparing two registered fluoroscopic
images by subtracting from each other and thresholding the
resulting subtracted image and computing the size of the
thresholded area. The two registered images are comprised of a
reference image and the current image or the two registered images
are comprised of two successive images.
Active Balloon Stabilization
[0036] An embodiment involves stabilizing an angioplasty or stent
deployment balloon in its proper position for activation using a
robotic feed mechanism. This may involve advancing or retracting
the working catheter that is deploying the balloon. The positioning
may be monitored by the examination of fluoroscopic images with
image processing software and the software may then signal the
needed amount of adjustment. For instance, if the balloon, with or
without stent, is being deployed over a lesion, image processing
software may monitor fluoroscopic images in which markers at both
ends of the balloon and the lesion appear and signal the
appropriate amount of advancement or retraction to assure that the
balloon is in its proper position for inflation.
[0037] The system may use a pre-computed 3D height map to correct
for foreshortening and compute the foreshortened adjusted length of
catheter that needs to be fed. The adjusted length of catheter is
provided to the robotic system to advance the catheter by that
amount.
[0038] The system may measure the length of the balloon in the 2D
fluoroscopic image and in infer the local 3D height at that
location by comparing the 2D length of the balloon to the known
length of the balloon using simple foreshortening trigonometry. The
height information is then to compute the foreshortened adjusted
length of catheter that needs to be fed. The adjusted length of
catheter is provided to the robotic system to advance the catheter
by that amount.
Guide Catheter Conduction of Ultrasound
[0039] An embodiment involves utilizing the guide catheter as an
ultrasonic conduit to determine its position. The boundary
conditions at the distal end of the conduit may be used to
determine whether it is properly seated.
X-Ray Imaging of Different Areas
[0040] An embodiment involves using multiple images of different
areas involved in a percutaneous interventional procedure. It may
be advantageous to use multiple fields of view and to tailor the
frequency of X-ray imaging to the particular field of view. For
instance, one field of view may involve all or most of the path of
percutaneous devices such as guide catheters, guide wires and/or
working catheters and another to involve the immediate area of the
site of action. It may be that more frequent imaging is appropriate
for the latter field of view. The differential sampling rates may
allow for reducing the overall X-ray exposure of the patient.
[0041] The position of the area of interest at the distal end of
the catheter may be updated by using an estimation of the velocity
of the catheter or guide write feed through the catheter guide to
position the window prior to the next fluoroscopic acquisition. The
velocity of the device being fed through the guide catheter may be
estimated using X-ray markers as discussed above.
Optimization of the Plane of fluoroscopic Images
[0042] An embodiment involves adjustment of the plane of
fluoroscopic images of the guide wire or working catheter as it
advances through and out of the guide catheter. It may be
advantageous to adjust the plane of the images to maximize the
portion of the travel of the device that is in the plane of the
fluoroscopic image. This may involve a comparison of the apparent
travel path in two-dimensional fluoroscopic images with the length
of the guide wire or working catheter that has been fed into the
guide catheter.
[0043] FIG. 1 shows the environment in which the various
embodiments of the present invention find particular utility. It
shows a catheter laboratory 10 for robotically performing
percutaneous interventional procedures. A patient 11 is supported
on a table 14 and the procedure is observed with fluoroscopic X-ray
equipment 12. A cassette 22 supported by a robotic arm 20 is used
to automatically feed a guide wire 50 (shown in FIG. 2) into a
guide catheter 40 seated in an artery 60 (shown in FIG. 5) of the
patient 11. The cassette 22 is controlled from a remote station 24
in order to isolate the medical personnel conducting the procedure
from exposure to the X-ray radiation used to monitor the procedure
by use of fluoroscopic equipment. The station includes remote
controls 26 for controlling the cassette 22 and a screen 28 with
which to monitor the progress of the procedure. It displays the
arterial system 29 being addressed by the procedure. U.S. Pat. No.
7,887,549, incorporated herein by reference, has a detailed
disclosure of this environment.
[0044] FIG. 2 shows a guide catheter 40 that has been fed into the
torso 30 of a patient 11 to reach the cardiac region 32. Within the
guide catheter 40 is a guide wire 50 whose tip 52 has not yet
passed out of the distal end 42 of the guide catheter 40. The X-ray
equipment which is used to monitor the progress of the guide wire
50 as it passes through the guide catheter 40 and approaches its
distal terminus 42 may be controlled such that it images the entire
path until the guide wire tip enters the cardiac region 32 and then
just images the cardiac region 32. It may also be controlled to
take images at a more frequent rate once the tip 52 enters the
region 32.
[0045] FIG. 3 shows a guide wire 50 which terminates at its distal
end with a tip 50 that contains an X-ray marker which is readily
apparent in a fluoroscopic image of the tip 52.
[0046] FIG. 4 shows a guide catheter 40 with a distal terminus 42
which has been provided with a distal X-ray marker 44, an
intermediate X-ray marker 46 and a proximate X-ray marker 48. Also
shown is the length 39 of the guide catheter 40 which extends from
its proximal end to the intermediate X-ray marker 48 as well as the
length 41 from there to the intermediate X-ray marker 46, the
length 43 from that X-ray marker to the distal X-ray marker 44 and
the length 45 from the distal X-ray marker 44 to the distal end of
the guide catheter 42. These markers 44, 46 and 48 and theses
lengths 39, 41, 43 and 45 may be used to control the movement of
guide wire or working catheters being fed through the guide
catheter 40. For instance, image-processing software may be used to
analyze iteratively successive fluoroscopic images of the distal
portion of the guide catheter and recognize when the X-ray marker
in the guide wire tip 52 has first passed the markers 48, 46 and
44. This information can then be used to control the movement and
speed of a guide wire 50 being fed to the guide catheter via its
proximal end. In one embodiment the guide wire 50 can be quickly
fed until its tip 52 until it reaches the marker 48 and then the
feed speed can be reduced and then the automatic feed can be
terminated when the tip 52 reaches the marker 46. In another
approach when the tip 52 reaches the marker 46 the feed speed is
reduced and the feed is terminated when the tip 52 reaches the
marker 44. This two stage feeding procedure provides automatic
feeding that ceases closer to the distal terminus 42 of the guide
catheter 40 with reduced risk of overshooting the terminus 42. The
distances 39,41, 43 and 45 may be used to set feeding velocities
appropriate for the rate of taking fluoroscopic images and the
latency time of the image processing software. Alternatively, these
distances may be used to calculate the effective feeding velocity
of the guide wire 50 and determine an appropriate time to terminate
the automatic feeding such that the tip 52 does not emerge from the
distal terminus 42.
[0047] FIG. 4 (a) shows an alternative in which just two markers 46
and 44 are used and the distance 43 is greater than distance 45.
This supports an approach in which the feed is slowed when marker
46 is reached and stopped when marker 44 is reached.
[0048] FIG. 4 (b) show an alternative in which an X-ray marker 43
has been provided immediately adjacent to the terminus 42 and each
of the markers 43, 44 and 46 has been given a distinctive character
so that the image processing software will be aided in
distinguishing them.
[0049] FIG. 5A-H show using X-ray markers and image processing
software to control an interventional procedure from feeding a
guide wire 50 to a guide catheter 40 to the secure placement of an
angioplasty balloon 80 across a lesion 62 in an artery 60.
[0050] In FIG. 5A the guide wire 50 is being fed at an accelerated
rate into a guide catheter 40 which is seated in an artery 60 with
its distal end adjacent to a lesion 62. The tip 52 has yet to cross
the intermediate marker 46.
[0051] In FIG. 5B the tip 52 has been detected as having passed the
intermediate marker 46 by the image processing software which is
analyzing iterative fluoroscopic images of the progress of the
guide wire 50 and this software has caused a decrease in the feed
velocity.
[0052] In FIG. 5C the image processing software has detected that
the tip 52 has passed the distal X-ray marker 44 and has further
slowed or stopped the feeding of the guide wire. In the latter case
a signal has been sent indicating to the medical personnel
conducting the procedure that manual advancement of the guide wire
is needed.
[0053] In FIG. 5D the tip 52 has been advanced out of the distal
terminus 42 of the guide catheter 40 and across the lesion 62. This
could have been done manually or by image processing software that
recognizes the lesion 62.
[0054] In FIG. 5E a working catheter 70 carrying an angioplasty
balloon 80 at its distal end has been advanced over the guide wire
50 but has not yet reached the X-ray marker 46. The balloon 80
carries X-ray markers at both its distal end 82 and its proximal
end 84.
[0055] In FIG. 5F the distal end 82 of the balloon 80 has passed
marker 46 and thus the image processing software has slowed the
feed rate of the working catheter 70.
[0056] In FIG. 5G the end 82 has passed marker 44. The image
processing software has either signaled to the medical personnel
conducting the procedure that manual advancement of the working
catheter 70 is needed or it has slowed the advancement rate.
[0057] In FIG. 5H the balloon has been advanced across the lesion
62 either manually or under control of image processing software
that can recognize the lesion 62. The balloon may carry a stent for
deployment across the lesion.
[0058] FIG. 6 shows a guide catheter 40 following the path of an
artery which is not illustrated. It has a portion 47 that has
passed below the plane 90 of the fluoroscopic image into a lower
plane 94 and it has a portion 49 that has passed above the plane 90
into a higher plane 92. iterative fluoroscopic images in plane 90
can be combined with measurements of the length of guide wire being
fed into the guide catheter can be combined to yield an indication
of the 3-D path of the guide catheter and therefore the artery
itself.
[0059] FIG. 7 shows a procedure that may be followed to develop the
indication of the 3-D path.
[0060] FIG. 8 describes a procedure for controlling the feeding of
a guide wire 50 to a guide catheter 40 such that it does not emerge
from the distal terminus 42 of the guide catheter using velocity
measurements.
[0061] FIG. 9 describes a procedure for controlling the feeding of
a guide wire 50 to a guide catheter 40 such that it does not emerge
from the distal terminus 42 of the guide catheter using iterative
fluoroscopic images.
[0062] While the foregoing written description of the invention
enables one of ordinary skill to make and use what is considered
presently to be the best mode thereof, those of ordinary skill will
understand and appreciate the existence of variations,
combinations, and equivalents of the specific embodiment, method,
and examples herein. The invention should therefore not be limited
by the above described embodiment, method, and examples, but by all
embodiments and methods within the scope and spirit of the
invention as claimed.
* * * * *