U.S. patent application number 10/852304 was filed with the patent office on 2005-01-06 for magnetically navigable and/or controllable device for removing material from body lumens and cavities.
Invention is credited to Garibaldi, Jeffrey, Hall, Andrew F., Lasala, John M., Werp, Peter R..
Application Number | 20050004585 10/852304 |
Document ID | / |
Family ID | 26861625 |
Filed Date | 2005-01-06 |
United States Patent
Application |
20050004585 |
Kind Code |
A1 |
Hall, Andrew F. ; et
al. |
January 6, 2005 |
Magnetically navigable and/or controllable device for removing
material from body lumens and cavities
Abstract
A magnetically navigable atherectomy device includes a cutting
head, a flexible drive shaft having a proximal and a distal end,
with the cutting device on the distal end, and a magnet associated
with the cutting head, the magnet of sufficient size to allow the
cutting head to be oriented by an externally applied magnetic
field. The magnet may be a portion of the cutting head made from a
magnetically permeable or permanent magnetic material, a portion of
the drive shaft made from a magnetically permeable or permanent
magnetic material; a separate magnet between the cutting head and
the drive shaft, a portion a magnet on a sheath covering the drive
shaft. Alternatively a guide wire can provided with a magnetic
material on its distal end. Through the application of a magnetic
field and/or a magnetic gradient, the artherectomy device can be
guided to the location of the atheromatous material in the body.
Once at the site of atheromatous material, through the application
of a magnetic field or magnetic gradient, the device can be
manipulated into proximity to the atheromatous material to remove
the material.
Inventors: |
Hall, Andrew F.; (St.
Charles, MO) ; Garibaldi, Jeffrey; (St. Louis,
MO) ; Werp, Peter R.; (St. Louis, MO) ;
Lasala, John M.; (St. Louis, MO) |
Correspondence
Address: |
HARNESS, DICKEY, & PIERCE, P.L.C
7700 BONHOMME, STE 400
ST. LOUIS
MO
63105
US
|
Family ID: |
26861625 |
Appl. No.: |
10/852304 |
Filed: |
May 24, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10852304 |
May 24, 2004 |
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10212458 |
Aug 5, 2002 |
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6740103 |
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10212458 |
Aug 5, 2002 |
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09281241 |
Mar 30, 1999 |
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6428551 |
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09281241 |
Mar 30, 1999 |
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09165694 |
Oct 2, 1998 |
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Current U.S.
Class: |
606/159 |
Current CPC
Class: |
A61B 2034/2051 20160201;
A61M 25/0127 20130101; A61B 2017/22042 20130101; A61B 34/20
20160201; A61B 2017/320004 20130101; A61B 17/320758 20130101 |
Class at
Publication: |
606/159 |
International
Class: |
A61B 017/22 |
Claims
What is claimed:
1. A device for removing material from the surface of body lumens
and cavities, the device comprising: a cutting head; and a magnet
associated with the cutting head, the magnet of sufficient size to
allow the cutting head to be oriented by an externally applied
magnetic field.
2. The device according to claim 1 wherein the magnet comprises a
portion of the cutting head made from a magnetically permeable or
permanent magnetic material.
3. The device according to claim 1 further comprising a flexible
drive shaft having a proximal and a distal end, with the cutting
device on the distal end, and wherein the magnet comprises a
portion of the flexible drive shaft being made of a magnetically
permeable or permanent magnetic material.
4. The device according to claim 1 wherein the magnet is a
magnetically permeable or permanent magnetic material disposed
between the cutting head and the flexible drive shaft.
5. The device according to claim 1 further comprising a sheath,
over the drive shaft, and wherein the magnet is on the distal end
of the sheath.
6. The device according to claim 1 further comprising a generally
axially extending passage through the cutting head and the drive
shaft for accommodating a guide wire.
7. A method of removing material from the surface of a body lumen
or cavity, the method comprising: introducing a guide wire having
magnetic material at its distal end into the body lumen or cavity,
and navigating the guide wire to the site of the material to be
removed by successively applying a magnetic field to orient the
distal end of the guide wire and advancing the guide wire in the
lumen or cavity to the site of the material to be removed;
advancing a tool having a cutting head for removing the material,
along the guide wire to the site of the material, and operating the
cutting head to remove the material from the walls of the blood
vessel.
8. The method according to claim 7 wherein the step of advancing
the guide wire comprises applying a magnetic field gradient to the
distal end of the guide wire to apply a motive force to move the
distal end of the guide wire.
9. The method according to claim 7 wherein the step of operating
the cutting head to remove the material comprises advancing the
tool over the guide wire into close proximity with the magnetic
material, and applying a magnetic field to the magnetic material to
orient the cutting head of the tool.
10. The method according to claim 7 wherein the step of operating
the cutting head to remove the material comprises advancing the
tool over the guide wire into close proximity with the magnetic
material, and applying a magnetic gradient to the magnetic material
to move the cutting head toward the material in the lumen or
cavity.
11. The method according to claim 7 wherein the step of operating
the cutting head to remove the material comprises advancing the
tool over the guide wire into close proximity with the magnetic
material, and applying a magnetic field to orient the cutting head
and a magnetic gradient to move the cutting head toward the
material in the lumen or cavity.
12. A method of removing material from the surface of a body lumen
or cavity, the method comprising: introducing a guide wire having
magnetic material at its distal end into the body lumen or cavity,
and navigating the guide wire to the site of the material to be
removed; advancing a tool having a cutting head for removing the
material, along the guide wire to the site of the material and into
close proximity with the magnetic material; and operating the
cutting head to remove the material from the walls of the lumen or
cavity by applying at least a magnetic field to orient the cutting
head or a magnetic gradient to move the cutting head within the
lumen or cavity.
13. The method according to claim 12 wherein the step of operating
the cutting head to remove the material comprises applying a
magnetic field to the magnetic material to orient the cutting head
of the tool toward the material in the lumen or cavity.
14. The method according to claim 12 wherein the step of operating
the cutting head to remove the material comprises applying a
magnetic gradient to the magnetic material to move the cutting head
toward the material in the lumen or cavity.
15. The method according to claim 12 wherein the step of operating
the cutting head to remove the material comprises applying both a
magnetic field to orient the cutting head and a magnetic gradient
to move the cutting head toward the material in the lumen or
cavity.
16. A method of removing material from the walls of a body lumen or
cavity, comprising: introducing a tool having a cutting head on its
distal end and a magnet associated with the cutting head into the
lumen or cavity, and navigating the tool to the site of the
material to be removed by successively applying a magnetic field to
orient the distal end of tool and advancing the tool in the lumen
or cavity to the site of the material to be removed; and operating
the cutting head to remove the material from the surface of the
lumen or cavity.
17. The method according to claim 16 wherein the step of advancing
the tool comprises applying a magnetic field gradient to the distal
end of the tool to apply a motive force to move the distal end of
the tool.
18. The method according to claim 16 wherein the step of operating
the cutting head to remove the material comprises applying a
magnetic field to the magnet associated with the cutting head to
orient the cutting head of the tool.
19. The method according to claim 16 wherein the step of operating
the cutting head to remove the material comprises applying a
magnetic field gradient to the magnetic material associated with
the cutting head to move the cutting head within the lumen or
cavity.
20. The method according to claim 16 wherein the magnet associated
with the cutting head is at least a part of the cutting head made
of a magnetic material.
21. A method of removing material from the walls of a body lumen or
cavity, comprising: introducing a tool having a cutting head on its
distal end and a magnet associated with the cutting head into the
lumen or cavity, and navigating the tool to the site of the
material to be removed; operating the cutting head to remove the
material from the surface of the lumen or cavity by applying at
least a magnetic field to orient the cutting head or a magnetic
gradient to move the cutting head within the lumen or cavity.
22. The method according to claim 23 wherein the step of operating
the cutting head to remove the material comprises applying a
magnetic field to the magnet associated with the cutting head to
orient the cutting head of the tool.
23. The method according to claim 23 wherein the step of operating
the cutting head to remove the material comprises applying a
magnetic gradient to the magnetic material associated with the
cutting head to move the cutting head within the lumen or
cavity.
24. The method according to claim 23 wherein the step of operating
the cutting head to remove the material comprises applying both a
magnetic field to orient the cutting head and a magnetic gradient
to move the cutting head toward the material in the lumen or
cavity.
25. The method according to claim 21 further comprising the step of
applying a continuously changing magnetic field to precess the
cutting head within the lumen or cavity.
26. The method according to claim 25 wherein the step of applying a
continuously changing magnetic field is done with a computer
controlled magnet.
27. The method according to claim 21 further comprising the step of
applying a continuously changing magnetic gradient to move the
cutting head within the lumen or cavity.
Description
FIELD OF THE INVENTION
[0001] This invention relates to devices for removing material from
body lumens and cavities, and in particular to such devices that
can be magnetically navigated and/or controlled.
BACKGROUND OF THE INVENTION
[0002] There are many medical conditions where it is desirable to
remove material from the surface of a body lumen or cavity. For
example in the case of occluded blood vessels, one method of
treating this condition to use a cutting tool in the blood vessel
to remove accumulated atheromatous material. These tools,
frequently called atherectomy devices, typically comprise a blade
or cutting bit or burr on the distal end of a flexible drive shaft.
The drive shaft is preferably contained within a flexible sheath to
protect the walls of the blood vessels from the rotation of the
drive shaft. Examples of such devices include Shiber, U.S. Pat. No.
4,842,579, Simpson et al., U.S. Pat. No. 5,047,040; and Auth et
al., U.S. Pat. No. 5,314,407, incorporated herein by reference.
[0003] An atherectomy device is typically navigated to the site of
the disease by mechanically manipulating a guide wire to the site
of the disease, and then advancing the atherectomy device over the
guide wire to the site. The navigation of the guide wire through
the blood vessel can be a slow and tedious process, requiring great
skill. Once at the site of the disease, it can be difficult to
precisely control the atherectomy device to satisfactorily remove
the atheromatous material. Part of this difficulty arises from
guide wire bias, for example as the atherectomy device traverses
bends in the blood vessels the guide wire and device tend to move
toward the outside of the bend, making it difficult to remove
atheromatous material from the insides of the bends. Even in
straighter segments of blood vessels, it is difficult to control
the position of the atherectomy device within the cross section of
the blood vessel, or the orientation of the cutting head of the
atherectomy device within the blood vessel, and thus it is
difficult to form a passage through the vessel larger than that
cross section of the tool.
SUMMARY OF THE INVENTION
[0004] The present invention relates to an atherectomy device that
can be magnetically controlled, and to the magnetic control of
atherectomy devices. Generally, the atherectomy device of the
present invention comprises a flexible drive shaft, with a cutting
head on the distal end of the drive shaft. A magnet is associated
with the cutting head. In one construction, the cutting head itself
is made of a magnetic material, either a permanent magnet or a
permeable magnet. In another construction a magnet is disposed
between the cutting head and the drive shaft. In still another
construction, the distal end portion of the drive shaft adjacent
the cutting head is magnetic. In still another construction, a
magnet is positioned on the distal end of the sheath, in proximity
to the cutting head. The magnet can be any material with magnetic
properties (i.e., responsive to a magnetic field or magnetic
gradient), and may either be a separate part or constitute a
magnetic portion of an existing part.
[0005] The magnet associated with the cutting head facilitates
navigation of the atherectomy device to the procedure site, and
control of the cutting head at the procedure site through the
application of a magnetic field and/or magnetic field gradient. A
magnetic field can be applied to orient the atherectomy device in
the blood vessel for navigating to the procedure site. The applied
magnetic field aligns the magnet associated with cutting head in
the direction of the field, so that the atherectomy device can be
more easily steered through the blood vessels. The device can then
be advanced in the desired direction simply by pushing on the
proximal end. Alternatively, or in addition, a magnetic field
gradient can be applied to the magnet associated with the cutting
head to apply force to the atherectomy device to actually move the
device through the blood vessel, or assist the mechanical pushing
of the device through the blood vessel. Once at the procedure site,
magnetic fields and/or magnetic field gradients can be applied to
the magnet associated with the cutting head to control the
orientation of the device and its position within the cross-section
of the blood vessel. Thus, with the application of a magnetic
field, the cutting portion of the cutting head can be oriented
toward the accumulated atheromatous material, and the cutting tool
itself can be moved within the cross-section of the blood vessel to
act on the accumulated atheromatous material, for example on the
insides of bends. Because the tool can be both oriented and moved,
the tool can open a passage in the blood vessel that is larger than
the cross section of the device itself. By automating the control
of the direction and/or gradient of the applied magnetic field, the
procedure can be automated, so that once the tool is navigated to
the site of the disease, the tool is automatically precessed to
clear the cross-section of the vessel in adjacent the atherectomy
device of the atheromatous material. In addition to precessing the
cutting head by continuously changing the magnetic field, it is
also possible to continuously move the cutting head around the
cross-section of the vessel by continuously varying the magnetic
gradient. Of course both the magnetic field and magnetic gradient
can be simultaneously changed to cause the orientation and the
position of the cutting head to change to remove material from
around the cross section of the vessel.
[0006] In accordance with another embodiment of this invention, it
is also possible that instead of, or in addition to, associating a
magnet with the cutting head, the atherectomy device can be used in
conjunction with a magnetic guide wire. A magnet can be provided on
the end of a conventional guide wire, or a portion of the guide
wire can be made magnetic. The guide wire is then navigated to the
diseased site. The magnet on or in the guide wire facilitates
orienting and/or moving the guide wire through the blood vessels.
Once at the site, the atherectomy device can be brought into close
association with the magnet on the guide wire, and the magnet on
the guide wire can be used to orient and to move the cutting head
within the blood vessel.
[0007] The atherectomy device of the present invention can be
quickly and easily navigated to the site of the disease. This makes
the procedure easier on the physician and the on patient. Once at
the site, the tool can be operated more effectively, removing
atheramotous material from around the entire circumference of the
blood vessel, and clearing a passageway larger than the cross
section of the atherectomy device itself. These and other features
and advantages will be in part apparent and in part pointed out
hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a partial longitudinal cross sectional view of an
atherectomy device constructed according the principles of this
invention;
[0009] FIG. 2 is a partial longitudinal cross sectional view of an
alternate construction of the atherectomy device, incorporating a
discrete magnet;
[0010] FIG. 3 is a partial longitudinal cross-sectional view of an
alternate construction of the atherectomy device, in which a
portion of the drive shaft is magnetic;
[0011] FIG. 4 is a partial longitudinal cross-sectional view of an
alternate construction of the atherectomy device, incorporating a
magnet on the sheath;
[0012] FIG. 5A is a longitudinal cross-sectional view of a blood
vessel showing an atherectomy device of the present invention
therein before the application of a magnetic gradient;
[0013] FIG. 5B is a longitudinal cross-sectional view of a blood
vessel showing an atherectomy device of the present invention
therein during the application of a magnetic gradient;
[0014] FIG. 6A is a longitudinal cross-sectional view of a curved
segment of a blood vessel showing an atherectomy device of the
present invention therein, before the application of a magnetic
gradient;
[0015] FIG. 6B is a longitudinal cross-sectional view of a curved
segment of a blood vessel showing an atherectomy device of the
present invention therein, during the application of a magnetic
gradient;
[0016] FIG. 7 is a transverse cross section of a blood vessel
showing the possible positions of an atherectomy device of the
present invention with the application of a magnetic gradient; FIG.
8 is a longitudinal cross-sectional view of the blood vessel
showing a atherectomy tool oriented by a magnetic field to remove
accumulated atheromatous material;
[0017] FIG. 9A is a partial longitudinal cross sectional view of an
atherectomy device constructed according to the principles of this
invention, employing a magnetic guide wire with a discrete
magnet;
[0018] FIG. 9B is a partial longitudinal cross sectional view of an
atherectomy device constructed according to the principles of this
invention, employing a magnetic guide wire with a magnetic portion;
and
[0019] FIG. 10 is a partial longitudinal cross sectional view of an
athrectomy device constructed according to the principles of this
invention without a guide wire.
[0020] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0021] An atherectomy device constructed according to the
principles of this invention is indicated generally as 20 in FIG.
1. While the drawings and description of this preferred embodiment
show and describe an atherectomy device for removing atheromatous
material from the walls of blood vessels, the invention is not so
limited, and applies to any magnetically navigable and/or
controllable device for removing material from the surface of a
body lumen or cavity. As shown in FIG. 1, the atherectomy device 20
comprises a flexible drive shaft 22 and a cutting head 24. The
drive shaft 22 is preferably made from a tight helically coiled
wire. The cutting head 24 is preferably an oblate spheroid, with an
abrasive, such as diamond particles on the distal end. The drive
shaft 22 rotates the cutting head 24, and the abrasive on the
distal end of the cutting head abrades the atheromatous material in
the vessel. There is a passage 26 through cutting head 24, and
through the drive shaft 22 for receiving a guide wire 28. The guide
wire 28 can be advanced in the blood vessel and then the
atherectomy device 20 is advanced over the guide wire to the
procedure site. The end 30 of the guide wire 28 may have a stop 32,
to prevent the guide wire from being withdrawn entirely into the
passage 26, and to blunt the end of the guide wire so that it does
not puncture the blood vessel. Of course, as described below, the
athrectomy device can be used without a guide wire and guided
magnetically. This is particularly advantageous in totally occluded
vessels where the guide wire cannot extend in front of the
atherectomy device because of the occlusion. According to the
principles of this invention, the cutting head 24 is made from or
contains a magnetic material, for example a permanent magnetic
materials such as Hiperco.RTM. (available from Carpenter Steel,
Reading, Pa.) or a permeable magnetic material such as
neodymium-iron-boron (Nd--Fe--B) (available from Magstar
Technologies, Minneapolis, Minn. The cutting head 24 may be coated
with an abrasive material, such as diamond dust embedded in the
distal surface of the head.
[0022] The drive shaft 22 is preferably enclosed in a sheath 34,
that protects the blood vessel from the rotating drive shaft. The
sheath 34 may be made of a conventional medical catheter material
such as polyvinylchloride.
[0023] A first alternative construction of the atherectomy device
20, indicated as 20', is shown in FIG. 2. The atherectomy device
20' is similar in construction to atherectomy device 20, except
that instead of the cutting head 24 being made from a magnetic
material, a magnet 36 is disposed between the drive shaft 22 and
the cutting head 24. This magnet may be a permanent magnetic
material such as Hiperco.RTM., or a permeable magnetic material
such as Nd--Fe--B.
[0024] A second alternative construction of the atherectomy device
20, indicated generally as 20", is shown in FIG. 3. The atherectomy
device 20" is similar in construction to atherectomy device 20,
except that instead of the cutting head 24 being made from a
magnetic material, the distal portion 38 of drive shaft 22 is
magnetic. This distal portion may be made from a permanent magnetic
material such as Hiperco.RTM. or a permeable magnetic material such
as Nd--Fe--B.
[0025] A third alternative construction of the atherectomy device
20, indicated generally as 20'" is shown in FIG. 4. The atherectomy
device is similar in construction to atherectomy device 20, except
that instead of the cutting head 24 being made from a magnetic
material, the distal portion of the sheath has a magnet 40 thereon.
The magnet may be embedded in the distal end portion of the
catheter, or secured on the end, for example with a suitable
medical grade adhesive. The cutting head can be retracted against
the magnet 40, so that the magnet is closely associated with the
cutting head 24.
[0026] Regardlesss of the means by which the magnet is associated
with the atherectomy device, a magnetic field can be applied to
orient the atherectomy device in the blood vessel for navigating to
the procedure site. The externally applied magnetic field may be
applied, for example with a magnetic surgery system like that
disclosed in co-pending U.S. patent application Ser. No.
08-920,446, filed Aug. 29, 1997, entitled Method and Apparatus for
Magnetically Controlling Motion Direction of a Mechanically Pushed
Catheter, incorporated herein by reference. The applied magnetic
field aligns the magnet associated with cutting head, e.g., the
magnetic cutting head 24 in device 20, the magnet 36 associated
with the cutting head in device 20', or the magnetic distal end
portion 38 of the drive shaft 22 in device 20", in the direction of
the field, so that the atherectomy device can be more easily
steered through the blood vessels. Once the distal end of the
device is oriented in the desired direction of travel by the
magnetic field, the device can then be advanced in the desired
direction simply by pushing on the proximal end. Alternatively, or
in addition, a magnetic field gradient can be applied to the to the
magnet associated with the cutting head to apply force to the
atherectomy device to actually advance the device through the blood
vessel. This force can be the only force used to move the
atherectomy device, or this force can merely be used to assist the
mechanical pushing of the device through the blood vessel.
[0027] Once at the site, magnetic fields can be applied to the
magnet associated with the cutting head to control the orientation
of the device and its position within the cross-section of the
blood vessel. Thus, with the application of a magnetic field, the
cutting portion of the cutting head can be oriented toward the
accumulated atheromatous material, and the cutting tool itself can
be moved within the cross-section of the blood vessel to act on the
accumulated atheromatous material, for example on the insides of
bends. FIG. 5A shows an atherectomy device 20 in a blood vessel.
The device is positioned generally along the guide wire 28.
However, as shown in FIG. 5B upon the application of a magnetic
field gradient, the cutting head 24 can be drawn toward the
accumulated atheromatous material, to more completely and
effectively abrade the material from the vessel wall. This
technique is particularly advantageous in the bends of blood
vessels, as shown in FIG. 6A, wherein the natural stiffness of the
guide wire and the device causes the atherectomy device to a
position away from the inside of the curve and toward the outside
of the curve. However, as shown in FIG. 6B, upon the application of
a magnetic field gradient, the cutting head 24 can be drawn against
the accumulated atheromatous a material on the inside of the bend,
to remove this material and more completely open the blood vessel.
As shown in FIG. 7, by controlling the direction of the applied
magnetic gradient, it is possible to move the cutting head to any
position in the cross section of the blood vessel.
[0028] As shown in FIG. 8, it is also possible to apply a magnetic
field to simply orient the cutting head 24, positioning the distal
abrasive cutting surface of the cutting head against the
atheromatous material on the vessel wall. The effects of
orientation with a magnetic field and positioning with a magnetic
gradient can be combined. While the gradient pulls the cutting head
into the atheromatous material, the field direction can be along
the axis of the vessel, to keep the cutting head oriented along the
vessel. Alternatively, the field direction can be at an angle with
respect to the vessel, to tilt the cutting head into the
atheromatous material.
[0029] Further, by continuously moving the applied magnetic field,
it is possible to precess the cutting head 24 around the
circumference of the vessel, moving the cutting head to clear
substantially the entire cross section of the vessel. By employing
a microprocessor control, or other automated control to change the
magnetic field as a function of time, the cutting tool can be
automatically precessed within the vessel. Thus the atherectomy
tool can be used to create a flow pathway through the vessel that
is actually larger than the cross section of the atherectomy
device. As the cutting head is precessing, it can be slowly
advanced across the accumulated atheromatous material. In addition
to precessing the cutting head by continuously changing the
magnetic field, it is also possible to continuously move the
cutting head around the cross-section of the vessel by continuously
varying the magnetic gradient. Of course both the magnetic field
and magnetic gradient can be simultaneously changed to cause the
orientation and the position of the cutting head to change to
remove material from around the cross section of the vessel.
[0030] In accordance with a second embodiment of this invention,
shown in FIG. 9A and 9B, it is also possible that instead of, or in
addition to, associating a magnetic with the cutting head, the
atherectomy device can be used in conjunction with a magnetic guide
wire 100, having a magnetic distal end portion. As shown in FIG.
9A, the guide wire 100 has a discrete magnet 102 on its distal end.
As shown in FIG. 9B, the distal end portion 104 of the guide wire
100 is made from a magnetic wire material. The guide wire is then
navigated to the diseased site. The magnet on or in the guide wire
facilitate orienting and/or moving the guide wire through the blood
vessels. Once at the site, the atherectomy device can be brought
into close association with the magnet on the guide wire, and the
magnet on the guide wire can be used to orient and to move the
cutting head within the blood vessel.
[0031] In accordance with a third embodiment of this invention,
shown in FIG. 10, the atherectomy device can be used without any
guide wire. The device is navigated solely by the application of
magnetic fields and/or gradients, which apply a force through the
magnet associated with the cutting head. One method of navigating
such an atherectomy device is that disclosed in co-assigned U.S.
patent application Ser. No. 60/095,710 filed Aug. 7, 1998, and
incorporated herein by reference. In this method of navigation, the
operating region in the patient is viewed on two planar
fluoroscopic images of the operating region. The physician
identifies the current position of the atherectomy device on each
display, for example by using a mouse or similar device to point
and click on the desired location. Similarly the physician can
identify the desired new position of the atherectomy device on each
display. A computer can control an electromagnetic system for
generating an electromagnetic field and/or gradient for orienting
and/or moving the distal end of the atherectomy device as input by
the physician. The distal end of the atherectomy device is advanced
manually or automatically, or in some cases it can be moved by a
magnetic field or gradient. In this manner, the atherectomy device
can be magnetically directed to the site of the occlusion without a
guide wire, and once at the site of the occlusion can be
magnetically manipulated to remove the material blocking the vessel
or lumen.
* * * * *