U.S. patent application number 12/436547 was filed with the patent office on 2010-02-11 for radially-firing electrohydraulic lithotripsy probe.
Invention is credited to Stan J. Lipowski, Robert Mantell, Chuck Zander, Joanna L. Zander.
Application Number | 20100036294 12/436547 |
Document ID | / |
Family ID | 41265087 |
Filed Date | 2010-02-11 |
United States Patent
Application |
20100036294 |
Kind Code |
A1 |
Mantell; Robert ; et
al. |
February 11, 2010 |
Radially-Firing Electrohydraulic Lithotripsy Probe
Abstract
Invasive side-firing electrohydraulic lithotripsy probes that
creates a substantially annular shockwave to break up concretions
are disclosed. Generally, the side-firing electrohydraulic
lithotripsy probe includes a lithotripter tip including a first
electrode and a second electrode. The first electrode is positioned
at a distal end of the lithotripter tip and the second electrode is
positioned in the lithotripter tip such that an end of the second
electrode is coaxially aligned with an end of the first electrode.
An electric arc between the first and second electrodes causes a
shockwave to radiate radially from the lithotripter tip.
Inventors: |
Mantell; Robert; (Arlington
Heights, IL) ; Lipowski; Stan J.; (Loves Park,
IL) ; Zander; Chuck; (McHenry, IL) ; Zander;
Joanna L.; (McHenry, IL) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Family ID: |
41265087 |
Appl. No.: |
12/436547 |
Filed: |
May 6, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61051262 |
May 7, 2008 |
|
|
|
Current U.S.
Class: |
601/4 ;
606/128 |
Current CPC
Class: |
A61B 17/22022 20130101;
A61B 2018/00988 20130101; A61B 2090/0814 20160201; A61B 2090/0803
20160201; G10K 15/06 20130101; A61B 2017/22098 20130101; A61B
2017/22025 20130101; A61B 2017/00734 20130101; A61B 2017/0023
20130101 |
Class at
Publication: |
601/4 ;
606/128 |
International
Class: |
A61B 17/22 20060101
A61B017/22 |
Claims
1. A lithotripter tip for use with a lithotripter probe, the
lithotripter tip comprising: a first electrode positioned at a
distal end of the lithotripter tip; and a second electrode, an end
of which is coaxially aligned with an end of the first electrode;
wherein the first and second electrodes are positioned on the
lithotripter tip such that an electric arc between the ends of the
first and second electrodes causes a shockwave that is at least
semi-annular to radiate radially from the lithotripter tip.
2. The lithotripter tip of claim 1, wherein the first electrode is
an anode and the second electrode is a cathode.
3. The lithotripter tip of claim 1, wherein the first electrode is
a cathode and the second electrode is an anode.
4. The lithotripter tip of claim 1, wherein at least a portion of
the second electrode is cylindrical in shape.
5. The lithotripter tip of claim 4, wherein the first electrode is
conic in shape.
6. The lithotripter tip of claim 5, wherein the first electrode is
supported by a plurality of conductive wires extending from the
distal end of the lithotripter tip.
7. The lithotripter tip of claim 4, wherein the first electrode is
positioned on an end of a hook structure extending from the distal
end of the lithotripter.
8. The lithotripter tip of claim 1, wherein the first and second
electrodes comprise electrically conductive material.
9. The lithotripter tip of claim 1, wherein the lithotripter tip is
at least partially surrounded by a flexible encapsulating
member.
10. An invasive lithotripter probe comprising: a lithotripter tip
comprising: a first electrode positioned at a distal end of the
lithotripter tip; and a second electrode, an end of which is
coaxially aligned with an end of the first electrode; wherein the
first and second electrodes are positioned on the lithotripter tip
such an electric arc between the ends of the first and second
electrodes causes a shockwave that is at least semi-annular to
radiate radially from the lithotripter tip; and a flexible
encapsulating member surrounding at least a portion of the
lithotripter tip, the balloon encapsulating a liquid.
11. The invasive lithotripter probe of claim 10, wherein the first
electrode is an anode and the second electrode is a cathode.
12. The invasive lithotripter probe of claim 10, wherein the first
electrode is a cathode and the second electrode is an anode.
13. The invasive lithotripter probe of claim 10, wherein at least a
portion of the second electrode is cylindrical in shape.
14. The invasive lithotripter probe of claim 13, wherein the first
electrode is conic in shape.
15. The invasive lithotripter probe of claim 14, wherein the first
electrode is supported by a plurality of conductive wires extending
from the distal end of the lithotripter tip.
16. The invasive lithotripter probe of claim 13, wherein the first
electrode is positioned on an end of a hook structure extending
from the distal end of the lithotripter.
17. The invasive lithotripter probe of claim 10, wherein the first
and second electrodes comprise electrically conductive
material.
18. An invasive lithotripter probe comprising: means for creating
an electrical arc between an end of a first electrode positioned at
a distal end of a lithotripter tip and an end of a second electrode
which is coaxially aligned with the end of the lithotripter tip;
and means for encapsulating a liquid around at least a portion of
the first and second electrodes; wherein the electrical arc between
the ends of the first and second electrodes causes a shockwave that
is at least semi-annular to radiate radially from the lithotripter
tip in the liquid.
Description
RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 61/051,262 (still pending), filed May 7,
2008, the entirety of which is hereby incorporated by
reference.
BACKGROUND
[0002] Electrohyrdaulic lithotripsy has been used in the medical
field, primarily for breaking concretions in the urinary or biliary
track. Conventional lithotripsy probes produce a shockwave that
radiates axially from a distal end of the lithotripsy probe. While
a shockwave radiating axially from a distal end of a lithotripsy
probe is useful in breaking up concretions such as a kidney stone,
it is often difficult to use these types of probes to break up
annular concretions, such as concretions around a heart valve.
Accordingly, improved lithotripsy probes are desirable for breaking
up concretions that are not located axially from a distal end of a
lithotripsy probe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a perspective view of one embodiment of a
radially-firing electrohydraulic lithotripsy probe;
[0004] FIG. 2 is a cross-sectional side view of the radially-firing
electrohydraulic lithotripsy probe of FIG. 1;
[0005] FIG. 3 is a perspective view of another embodiment of a
radially-firing electrohydraulic lithotripsy probe;
[0006] FIG. 4 is a cross-sectional side view of the radially-firing
electrohydraulic lithotripsy probe of FIG. 3;
[0007] FIG. 5 is a perspective view of another embodiment of a
radially-firing electrohydraulic lithotripsy probe;
[0008] FIG. 6 is a cross-sectional side view of the radially-firing
electrohydraulic lithotripsy probe of FIG. 5;
[0009] FIG. 7 is a side view of the radially-firing
electrohydraulic lithotripsy probe of FIG. 5;
[0010] FIG. 8a is a cross-section of an EHL probe including a
fusible link;
[0011] FIG. 8b is a flow chart for a method of using the EHL probe
of FIG. 8a;
[0012] FIG. 9a is a cross-section of an EHL probe including a smart
memory chip;
[0013] FIG. 9b is a flow chart of a method for using the EHL probe
of FIG. 9b;
[0014] FIG. 10a is a cross-section of an EHL probe including a
fusible link and a smart memory chip;
[0015] FIG. 10b is a flow chart of a method for using the EHL probe
of FIG. 10b;
[0016] FIG. 11a is a cross-section of an EHL probe including a
first fusible link and a second fusible link;
[0017] FIG. 11b is a flow chart of a method for using the EHL probe
of FIG. 11a;
[0018] FIG. 12 is a side view of a reinforced EHL probe; and
[0019] FIGS. 13a, 13b, 13c, and 13d illustrate enlarged views of a
rounded tip of an EHL probe.
DETAILED DESCRIPTION OF THE DRAWINGS
[0020] The present disclosure is directed to an invasive
radially-firing electrohydraulic lithotripsy probe that creates a
substantially annular shockwave for uses such as breaking up
concretions that are at least semi-annular or disrupting tissue of
a body organ. Generally, embodiments of the disclosed
radially-firing electrohydraulic lithotripsy ("EHL") probes include
a first electrode at a distal end of the probe, and a second
electrode coaxially aligned with the first electrode. A difference
in voltage polarities between the first and second electrodes
causes an electric arc, resulting in a shockwave that is at least
semi-annular that radiates radially from the lithotripsy probe.
[0021] In one implementation, the EHL probes described below may be
delivered to a proper channel of a heart by threading (or
pre-loading) an EHL probe through a center lumen of a catheter or
balloon device. The catheter may be threaded through appropriate
veins or arteries to address concretions either forming in vessels
or even in the valves of the heart or other organs.
[0022] In other implementations, the EHL probes described below may
be delivered to a small lumen of a body organ for the purpose of
disturbing or disrupting (distressing) tissue of the body organ in
such a way as to cause a stricture or a "scarring" of the tissue
for the purpose of creating a permanent stricture or blockage of
the lumen. For example, the EHL probes described below may be used
to purposely create a blockage in a fallopian tube for the purpose
of preventing pregnancies (sterilization). A fallopian tube, which
is approximately 1 mm in diameter, would have one of the EHL probes
described below threaded into it. The EHL probe may be threaded
through the fallopian tube(s) to address the inner surface of the
fallopian tube. Upon generating the EHL spark and subsequent
pressure wave in a radial manner, a rupturing or disrupting of the
walls of the inner surface of the fallopian tube can be
accomplished. The subsequent healing or scarring of the walls cause
the walls of the inner surface of the fallopian tube to knit
together and create a blockage that renders the fallopian tube
non-functional, thereby sterilizing a patient and preventing
pregnancies.
[0023] Referring to FIGS. 1 and 2, one embodiment of a
radially-firing EHL probe 100 (the "probe 100") includes a
lithotripsy probe tip 101 including an insulating body 102, a first
electrode 104, and a second electrode 106. Typically, the first
electrode 104 is positioned at a first distal end 108 of the
lithotripsy probe tip 101. In one implementation, the first
electrode 106 is conic in shape and includes an electrically
conductive material such as copper, silver, or stainless steels.
However, the first electrode 106 may be other shapes such as a
curved surface and/or made of other electrically conductive
material.
[0024] The first electrode 104 is supported by a plurality of wires
110 extending from the first distal end 108 of the lithotripsy
probe tip 101. The plurality of wires 110 are made of an
electrically conductive material, such as copper, silver, stainless
steel, or other conductive materials, and electrically coupled with
a first electrically conductive structure 112 in the EHL probe 100.
Typically, the plurality of wires 110 are insulated other than
where the plurality of wires 110 are electrically coupled with the
first electrode 104 and the first electrically conductive structure
112. As known in the art, the first conductive structure 112 may be
coupled with an electrical source, such as an electrohydraulic
generator (Autolith, Supplied by Norhgate Technologies Inc.), used
to charge the first electrode 104 to a first polarity.
[0025] The second electrode 106 is positioned in the body of the
lithotripsy probe tip 101. In one implementation, at least an end
114 of the second electrode 106 is cylindrical and includes an
electrically conductive material such as copper, silver, stainless
steel, or other conductive materials. However, the second electrode
106 may be other shapes. The second electrode 106 is positioned in
the lithotripsy probe tip 101 such that the second electrode 106 is
coaxially, and in some implementations symmetrically, aligned with
the first electrode 104. For example, when the first electrode 104
is conic in shape and an end 114 of the second electrode 106 is
cylindrical, the first and second electrodes 104, 106 are
positioned such that an axis extending from the conic first
electrode 104 is substantially aligned with an axis extending from
the cylindrical portion of the second electrode 106.
[0026] In some implementations, a distance between a tip of the
first electrode 104 and a point on the second electrode 106 closest
to the first electrode is 0.021 inch. However, various distances
between 0.006 and 0.100 inch could be used depending on the
application and the amount of energy to be transmitted.
[0027] The second electrode 106 is electrically coupled with a
second electrically conductive structure 116 in the EHL probe 100.
As known in the art, the second electrically conductive structure
116 may be coupled with an electrical source and used to charge the
second electrode to a second polarity, which is opposite to the
first polarity of the first electrode 104.
[0028] In one implementation, the first electrode 104 is an anode
and the second electrode 106 is a cathode, where in other
implementations, the first electrode 104 is a cathode and the
second electrode 106 is an anode. When the first electrode 104 is
charged to a first polarity via the first conductive structure 112
and the second electrode 106 is charged to a second, opposite
polarity via the second conductive structure 114, a discharge of
electricity occurs between the first and second electrodes 104, 106
(an electrical arc) when the potential between the first and second
electrodes 104, 106 reaches the breakdown voltage for the media
separating the electrodes.
[0029] In some implementations, such as the heart application
described above, at least a portion of the lithotripsy probe tip
101 including the first and second electrodes 104, 106 is
surrounded by a flexible encapsulating member 118, such as a
balloon, comprising a water-tight flexible material such as Mylar.
The flexible encapsulating member 118 encapsulates a liquid such as
saline. However, other liquids can be used. When an electrical arc
occurs between the first and second electrodes 104, 106 as
described above, the electrical arc causes a steam bubble in the
liquid of the flexible encapsulating member 118. The steam bubble
rapidly expands and contracts back on itself. As the steam bubble
contracts, a pressure wave (a shockwave) is created in the liquid
of the flexible encapsulating member 118 that radiates away from
the lithotripsy tip 101 in a substantially radial manner such that
the shockwave is at least semi-annular. However, in other
implementations, a flexible encapsulating member 118 does not
surround the lithotripsy probe tip 101.
[0030] Another embodiment of a radially-firing EHL probe is
described below with respect to FIG. 3 and 4. The radially-firing
EHL probe 300 (the "probe 300") includes a lithotripsy probe tip
301 including an insulating body 302, a first electrode 304, and a
second electrode 306. Similar to the embodiment described above
with respect to FIGS. 1 and 2, the first electrode 304 is
positioned at a first distal end 308 of the lithotripsy probe tip
301. The first electrode 304 is positioned on an end of a hook
structure 310 extending from the first distal end 308 of the
lithotripsy probe tip 301. The hook structure 310 may be other
shapes that extend from the first distal end 308 of the lithotripsy
probe tip 301 and curve back towards the lithotripsy probe tip 301
so that the first electrode 304 may be positioned at an end of the
structure 310 and coaxially aligned with the second electrode 306
as explained in more detail below.
[0031] The hook structure 310 includes an electrically conductive
material such as copper, silver, stainless steel, or other
conductive materials, and is electrically coupled with a first
electrically conductive structure 312 in the EHL probe 300. In some
implementations, the hook structure 310 is insulated other than
where the hook structure 310 is electrically coupled with the first
electrode 304 and at the first electrode 304 As known in the art,
the first electrically conductive structure 312 may be electrically
coupled with an electrical source and used to charge the first
electrode 304 to a first polarity.
[0032] The second electrode 306 is positioned in body of the
lithotripsy probe tip 301. In one implementation, at least an end
314 of the second electrode 306 is cylindrical and includes an
electrically conductive material such as copper, silver, stainless
steel, or other conductive materials. However, the second electrode
306 may be other shapes. The second electrode 306 is positioned in
the lithotripsy probe tip 301 such that the second electrode 306 is
coaxially, and in some implementations symmetrically, aligned with
the first electrode 304. For example, when an end 314 of the second
electrode 306 is cylindrical, an axis extending from the
cylindrical portion of the second electrode 306 is substantially
aligned with the first electrode 304 positioned on the hook
structure 310.
[0033] In some implementations, a distance between the first
electrode 304 and a point on the second electrode 306 closest to
the first electrode is 0.021 inch. However, various distances
between 0.006 and 0.100 inch could be used depending on the
application and the amount of energy to be transmitted.
[0034] The second electrode 306 is electrically coupled with a
second electrically conductive structure 316 in the EHL probe 300.
As known in the art, the second electrically conductive structure
316 may be electrically coupled with an electrical source and used
to charge the second electrode to a second polarity, which is
opposite to the first polarity of the first electrode 304.
[0035] In one implementation, the first electrode 304 is an anode
and the second electrode 306 is a cathode, where in other
implementations, the first electrode 304 is a cathode and the
second electrode 306 is an anode. When the first electrode 304 is
charged to a first polarity via the first electrically conductive
structure 312 and the second electrode 306 is charged to a second,
opposite polarity via the second electrically conductive structure
314, a discharge of electricity occurs between the first and second
electrodes 304, 306 (an electrical arc) when the potential between
the first and second electrodes 304, 306 reaches the breakdown
voltage for the media separating the electrodes.
[0036] In some implementations, at least a portion of the
lithotripsy probe tip 301 including the first and second electrodes
304, 306 is surrounded by a flexible encapsulating member 318, such
as a balloon, comprising a water-tight flexible material such as
Mylar. The flexible encapsulating member 318 encapsulates a liquid
such as saline. However, other liquids can be used. When an
electrical arc occurs between the first and second electrodes 304,
306 as described above, the electrical arc causes a steam bubble in
the liquid of the flexible encapsulating member 318. The steam
bubble rapidly expands and contracts back on itself. As the steam
bubble contracts, a pressure wave (a shockwave) is created in the
liquid of the flexible encapsulating member 118 that radiates away
from the lithotripsy tip 301 in a radial manner such that the
shockwave is at least semi-annular. However, in other
implementations, a flexible encapsulating member 318 does not
surround the lithotripsy probe tip 301.
[0037] Yet another embodiment of a radially-firing EHL probe is
described below with respect to FIGS. 5, 6, and 7. The
radially-firing EHL probe 500 (the "probe 500") includes a
lithotripsy probe tip 501 including an insulating body 502, a first
electrode 504, and a second electrode 506. The first and second
electrodes 504, 506 are positioned on a side-firing structure 508
of the lithotripsy probe tip 501. An axis of the side-firing
structure 508 is typically angled approximately 90 degrees from the
longitudinal axis of the lithotripsy probe 501 so that, as
explained below, the lithotripsy probe tip 501 may create a
directed shockwave that radiates away from the lithotripsy probe
tip 501 at approximately a 90 degree angle from the longitudinal
axis of the lithotripsy probe 501.
[0038] In one implementation, the first electrode 504 may be a
cylindrical sleeve positioned on an exterior of the side-firing
structure 508. However, the first electrode 504 may be other
shapes. The first electrode 504 is electrically coupled with a
first electrically conductive structure 510 in the EHL probe 500.
As known in the art, the first electrically conductive structure
510 may be electrically coupled with an electrical source and used
to charge the first electrode 504 to a first polarity.
[0039] The second electrode 506 is coaxially aligned with the first
electrode 504. In one implementation, the first electrode 504 is a
cylindrical sleeve and the second electrode 506 is a cylindrical
core that is positioned within the interior of the first electrode
504 such that the axis of the cylindrical sleeve of the first
electrode 504 substantially aligns with the cylindrical core of the
second electrode 506.
[0040] The second electrode 506 is electrically coupled with a
second electrically conductive structure 512 in the EHL probe 500.
As known in the art, the second electrically conductive structure
512 may be electrically coupled with an electrical source and used
to charge the second electrode 506 to a second polarity, which is
opposite to the first polarity of the first electrode 504.
[0041] In one implementation, the first electrode 504 is an anode
and the second electrode 506 is a cathode, where in other
implementations, the first electrode 504 is a cathode and the
second electrode 506 is an anode. When the first electrode 504 is
charged to a first polarity via the first conductive structure 510
and the second electrode 506 is charged to a second, opposite
polarity via the second conductive structure 512, a discharge of
electricity occurs between the first and second electrodes 504, 506
(an electrical arc) when the potential between the first and second
electrodes 504, 506 reaches the breakdown voltage for the media
separating the electrodes.
[0042] In some implementations, at least a portion of the
lithotripsy probe tip 501 including the first and second electrodes
504, 506 is surrounded by a flexible encapsulating member 514, such
as a balloon, comprising a water-tight flexible material such as
Mylar. The flexible encapsulating member 514 encapsulates a liquid
such as saline. However, other liquids can be used. When an
electrical arc occurs between the first and second electrodes 504,
506 as described above, the electrical arc causes a steam bubble in
the liquid of the flexible encapsulating member 514. The steam
bubble rapidly expands and contracts back on itself. As the steam
bubble contracts, a pressure wave (a shockwave) is created in the
liquid of the flexible encapsulating member 514 that radiates away
from the side-firing structure 508 in an axial manner, so that the
shockwave radiates away from the lithotripsy probe tip 501 in a
radial manner. However, in other implementations, a flexible
encapsulating member 514 does not surround the lithotripsy probe
tip 501.
[0043] One concern with EHL probes is a breakdown of the EHL probe,
also known as the End of Life of an EHL probe. In some
implementations, an electrical source such as an electrohydraulic
generator connected to an EHL probe may track a number of times it
fires an EHL probe. Based on the number of times the EHL probe
fires, power levels used during the firing of the EHL probe, and
historical End of Life data for EHL probes, the electrical source
may then determine when the EHL probe is nearing End of Life.
[0044] When an EHL probe nears End of Life, an electrical source
may display messages such as "End of Life" or "Change Probe" to
warn a doctor to dispose of an EHL probe. In some implementations,
an EHL probe may be designed to disable the EHL probe after
reaching or nearing End of Life.
[0045] FIG. 8a is a cross-section of an EHL probe 804 including a
fusible link 802. Generally, the fusible link 802 is used to
disable the EHL probe 804 when the EHL probe nears End of Life. In
one implementation, the fusible link 802 may be placed in a
connector 806 of the EHL probe 804. However, in other
implementations, the fusible link 802 may be placed in other
portions of the EHL probe 804.
[0046] Generally, an electrical source 808 monitors a number of
times the EHL probe 804 fires and power levels used during firing
of the EHL probe 804. The electrical source 808 compares the number
of times the EHL probe 804 fires and power levels used during
firing of the EHL probe 804 to historical End of Life data for EHL
probes. When the electrical source 808 determines the EHL probe 804
is near End of Life, the electrical source 808 send a short blast
of high current to the EHL probe 804. In one implementation, the
short blast of high current is 150 milliamps. When the short blast
of high current reaches the fusible link 802 in the EHL probe 804,
the high current causes a fuse within the fusible link 802 to
"open" (vaporizing some of the wire to open a circuit), thereby
disabling the EHL probe 804. In some implementations, the fusible
link 802 includes a sense resistor 803 placed between two pins,
however other implementations do not include the sense resistor
803.
[0047] In some implementations, the electrical source 808 may
measure an interior resistance of an EHL probe 804 so that the
electrical source 808 can determine when the EHL probe 804 has been
disabled.
[0048] FIG. 8b is a flow chart of a method for using the EHL probe
described above with respect to FIG. 8a. At step 810 an electrical
source measures an interior resistance of an EHL probe to determine
whether the EHL probe has been disabled. The electrical source may
perform step 810 when the EHL probe is first connected to the
electrical source, periodically, before each firing of the EHL
probe, and/or after each firing of the EHL probe.
[0049] If the electrical source determines at step 810 that the EHL
probe has been disabled, the method proceeds to step 811 where the
electrical source displays a message such as "End of Life" or
"Change Probe" to warn a doctor to dispose of the EHL probe.
However, if the electrical source determines at step 810 that the
EHL probe has not been disabled, the method proceeds to step 812
where the electrical source monitors a number of times an EHL probe
fires and power levels used during firing of the EHL probe.
[0050] At step 814, the electrical source compares the number of
times the EHL probe has fired and the power levels used during
firing of the EHL probe to historical End of Life data for EHL
probes to determine whether the EHL probe is near End of Life. The
electrical source may perform step 814 periodically, before each
firing of the EHL probe, and/or after each firing of the EHL
probe.
[0051] If the electrical source determines at step 814 that the EHL
probe is not near End of Life, the method loops to step 812 and the
electrical source continues to monitor the number of times an EHL
probe fires and power levels used during firing of the EHL probe.
However, if the electrical source determines at step 812 that the
EHL probe is near End of Life, the method proceeds to step 816.
[0052] At step 816, the electrical source sends a short blast of
high current to the EHL probe to cause a fuse within the fusable
link of the EHL probe to open, thereby disabling the EHL probe. At
step 818, the electrical source may display a message such as "End
of Life" or "Change Probe" to warn a doctor to dispose of the EHL
probe.
[0053] It will be appreciated that the order of the one or more
steps of the method described with respect to FIG. 8b may be
changed. Further, in some implementations, the method of FIG. 8b
may be implemented in conjunction with a computer-readable storage
medium comprising a set of instructions to direct a processor of
the electrical source to perform one or more of the above-described
acts.
[0054] FIG. 9a is a cross-section of an EHL probe 902 including a
smart memory chip 904. The smart memory chip 904 may be any flash
memory device small enough to be positioned in a connector of the
EHL probe 902. One example of such a flash memory device is a
128k.times.8 monolithic flash chip by White Electronics Designs
Corp. (part number WMF-128k8-xclx5). Generally, each time an
electrical source 906 fires the EHL probe 902, the electrical
source 906 also sends a count signal to the smart memory chip 904.
The smart memory chip 904 monitors a number of times the EHL probe
902 has been fired. When the EHL probe 902 is near End of Life, the
smart memory chip 904 may disable the EHL probe 902 and prevent the
EHL probe 902 from firing.
[0055] In some implementations, the EHL probe 902 may include an
internal power source 908 such as a battery so that the smart
memory chip 904 may maintain a count of the number of times the EHL
probe 902 has fired even when the EHL probe 902 is disconnected
from the electrical source 906. In some implementations the smart
memory chip 904 may additionally include a unique identifier, such
as a serial number, so that the EHL probe 902 is uniquely
identified to the electrical source 906 when the EHL probe 902 is
first connected to the electrical source 906. The electrical source
906 may use the unique identifier for purposes such as record
keeping, performance analysis, or trouble shooting of faulty EHL
probes 902.
[0056] FIG. 9b is a flow chart of a method for using the EHL probe
described above with respect to FIG. 9a. At step 910, an EHL probe
is connected to the electrical source. At step 912, the electrical
source retrieves a unique identifier from a memory of the EHL probe
to identify the EHL probe to the electrical source.
[0057] At step 914, the electrical source retrieves a count of a
number of times the EHL probe has been fired from the memory of the
EHL probe. At step 916, the electrical source determines whether
the EHL probe is near End of Life by comparing the number of times
the EHL probe has been fired to a threshold.
[0058] If the electrical source determines at step 916 that the EHL
probe is near End of Life, the electrical source disables the EHL
probe at step 917. Additionally, the electrical source may display
a message such as "End of Life" or "Change Probe" to warn a doctor
to dispose of the EHL probe at step 918.
[0059] However, if the electrical source determines at step 916
that the EHL probe is not near End of Life, the method proceeds to
step 920 where the electrical source sends a count signal to the
memory of the EHL probe to increment the number of times the EHL
probe has been fired. At step 922, the electrical source fires the
EHL probe. The method then loops to step 914.
[0060] It will be appreciated that the order of one or more steps
of the method described above with respect to FIG. 9b may be
changed. For example, the electrical source may fire the EHL probe
(step 922) before incrementing the number of times the EHL probe
has been fired (step 920). Further, in some implementations, the
method of FIG. 9b may be implemented in conjunction with a
computer-readable storage medium comprising a set of instructions
to direct a processor of the electrical source to perform one or
more of the above-described acts.
[0061] FIG. 10a is a cross-section of an EHL probe 1002 including a
fusible link 1004 and a smart memory chip 1006. It will be
appreciated that in implementations including both the fusible link
1004 and the smart memory chip 1006, the fusible link 1004 may
function as described above in conjunction with FIG. 8 to disable
the EHL probe 1002 in response to a short blast of high current
from an electrical source 1008. Additionally, the smart memory chip
1006 may function as described above in conjunction with FIG. 9 to
disable the EHL probe 1002 when the smart memory chip 1006
determines based on a number of times the EHL probe 1002 has fired
that the EHL probe 1002 is near End of Life.
[0062] FIG. 10b is a flow chart of a method for using the EHL probe
of FIG. 10a. At step 1010, an EHL probe is connected to the
electrical source. At step 1012, the electrical source retrieves a
unique identifier from a memory of the EHL probe to identify the
EHL probe to the electrical source. At step 1014, the electrical
source measures an interior resistance of the EHL probe to
determine whether the EHL probe has been disabled.
[0063] If the electrical source determines at step 1014 that the
EHL probe has been disabled, the method proceeds to step 1015 where
the electrical source displays a message such as "End of Life" or
"Change Probe" to warn a doctor to dispose of the EHL probe.
However, if the electrical source determines at step 1014 that the
EHL probe has not been disabled, the method proceeds to step
1016.
[0064] At step 1016, the electrical source retrieves a count of a
number of times the EHL probe has been fired from the memory of the
EHL probe. At step 1018, the electrical source determines whether
the EHL probe is near End of Life by comparing the number of times
the EHL probe has been fired to a threshold.
[0065] If the electrical source determines at step 1018 that the
EHL probe is near End of Life, the method proceeds to step 1020
where the electrical source sends a short blast of high current to
the EHL probe to cause a fuse within the fusable link of the EHL
probe to open, thereby disabling the EHL probe. At step 1022, the
electrical source may display a message such as "End of Life" or
"Change Probe" to warn a doctor to dispose of the EHL probe.
[0066] If the electrical source determines at step 1018 that the
EHL probe is not near End of Life, the method proceeds to step 1024
where the electrical source sends a count signal to the memory of
the EHL probe to increment the number of times the EHL probe has
been fired. At step 1026, the electrical source fires the EHL
probe. The method then loops to step 1016.
[0067] It will be appreciated that the order of one or more steps
of the method described above with respect to FIG. 10b may be
changed. Further, in some implementations, the method of FIG. 10b
may be implemented in conjunction with a computer-readable storage
medium comprising a set of instructions to direct a processor of
the electrical source to perform one or more of the above-described
acts.
[0068] FIG. 11a is a cross-section of an EHL probe 1102 including a
first fusible link 1104 and a second fusible link 1106. Generally,
when the EHL probe 1102 is first fired, the first fusible link 1104
is blown so that the EHL probe cannot be reused (protecting its
single use designation). Additionally, when an electrical source
determines the EHL probe 1102 is near End of Life, the electrical
source may send a short blast of high current to the EHL probe 1102
to blow the second fusible link 1106 as described above in
conjunction with FIG. 8, thereby disabling the EHL probe 1102.
[0069] FIG. 11b is a flow chart of a method for using the EHL probe
described above with respect to FIG. 11a. At step 1110 an EHL probe
is connected to an electrical source. At step 1112, the electrical
source measures an interior resistance of the EHL probe with
respect to a first fuse to determine if the EHL probe has been
previously fired. If the electrical source determines at step 1112
that the EHL probe has been fired, the method proceeds to step 1114
where the electrical source displays a message such as "End of
Life" or "Change Probe" to warn a doctor to dispose of the EHL
probe.
[0070] If the electrical source determines at step 1112 that the
EHL probe has not been previously fired, the method proceeds to
step 1116 where the electrical source measures an interior
resistance of the EHL probe with respect to a second fuse to
determine whether the EHL has been disabled because it is near End
of Life. If the electrical source determines at step 1116 that the
EHL probe has been disabled, the method proceeds to step 1118 where
the electrical source displays a message such as "End of Life" or
"Change Probe" to warn a doctor to dispose of the EHL probe.
[0071] If the electrical source determines at step 1118 that the
EHL probe has not been disabled, the method proceeds to step 1120
where the electrical source sends a short blast of high current to
the EHL probe to cause the first fuse within the fuseable link of
the EHL probe to open before the EHL probe is fired for the first
time. At step 1122 the electrical source monitors a number of times
an EHL probe fires and power levels used during firing of the EHL
probe.
[0072] At step 1124, the electrical source compares the number of
times the EHL probe has fired and the power levels used during
firing of the EHL probe to historical End of Life data for EHL
probes to determine whether the EHL probe is near End of Life. If
the electrical source determines at step 1124 that the EHL probe is
not near End of Life, the method loops to step 1122 and the
electrical source continues to monitor the number of times an EHL
probe fires and power levels used during firing of the EHL
probe.
[0073] If the electrical source determines at step 1124 that the
EHL probe is near End of Life, the method proceeds to step 1126
where the electrical source sends a short blast of high current to
the EHL probe to cause the second fuse within the fusable link of
the EHL probe to open, thereby disabling the EHL probe. At step
1128, the electrical source may display a message such as "End of
Life" or "Change Probe" to warn a doctor to dispose of the EHL
probe.
[0074] It will be appreciated that the order one or more steps of
the method described with respect to FIG. 11b may be changed.
Further, in some implementations, the method of FIG. 11b may be
implemented in conjunction with a computer-readable storage medium
comprising a set of instructions to direct a processor of the
electrical source to perform one or more of the above-described
acts.
[0075] Because of the delicate nature of small EHL probes and the
long paths that may be required to insert an EHL probe through body
channels or through sheaths or endoscopes, EHL probes in excess of
250 cm are desirable. The EHL probes described above with respect
to FIGS. 1-11 may be constructed to allow for insertion of the EHL
probe into channel in excess of 250 cm by improving a linear
strength of the EHL probe without significantly reducing the
performance or flexibility of the EHL probe.
[0076] FIG. 12 is a side view of a reinforced EHL probe 1200. In
one implementation, the linear strength of an EHL probe 1200 is
improved by placing a stiffening over-sheath 1202 partially over
the EHL probe 1200. The stiffening over-sheath 1202 may be
constructed of materials such as Kynar.RTM., Pebax.RTM., or other
similar materials.
[0077] In another implementation, the linear strength of an EHL
probe 1200 is improved by using non-kinking formulations of a
polyimide sheath material, such as those with thicker insulation,
or ribbed or ringed areas along a length of a sheath or insulating
material 1204. Examples of these types of materials are provided by
Micro Lumen.
[0078] In yet other implementations, the linear strength of an EHL
probe 1200 is improved by using an outer sheath 1204 of a polyimide
sheath/insulation either coated or impregnated with lubricious
materials such as Teflon or hydrophilic coatings. The more
lubricious surface of the EHL probe would reduce a linear friction
of the EHL probe as it is inserted through long channels.
[0079] In another implementation, the linear strength of an EHL
probe 1200 is improved by using conductor wire 1206 of special
manufacture, such as stainless steel wire with copper coating. The
stainless steel center would provide greater stiffness for push
strength, and the copper coating would provide for a less resistive
current path. Because EHL probes 1200 are often used in a radio
frequency (RF) range, and RF currents tend to flow at the surface
of a wire rather than at the core of the wire, the added resistance
of the stainless steel wire would not significantly affect the EHL
probe 1200 performance.
[0080] In some embodiments, one or more of the implementations
described above for improving the linear strength of the EHL probe
1200 may increase the linear strength of the EHL probe 1200 by
approximately 50%.
[0081] In yet another implementation, an EHL probe 1200 is
constructed to allow for insertion into long channels by rounding a
tip 1208 of the EHL probe 1200 as shown in FIGS. 13a, 13b, 13c, and
13d. By rounding the tip 1208 of the EHL probe 1200, the tip 1208
of the EHL probe 1202 would be more likely to slide and prevent the
tip 1208 of the EHL probe 1202 from "digging" into tissue, or a
sheath or a scope.
[0082] Electrical sources such as those described above with
respect to FIGS. 1-13 may use spark gap technology. The gaps used
in spark gap technology may be sealed, noble gas spark discharge
tubes that have an approximate life of approximately 400,000 to
500,000 discharges. After approximately 400,000 to 500,000
discharges, the gaps can no longer "break over" at a proper
voltage.
[0083] An electrical source used with an EHL probe may record
information such as a number of times a gap fires an EHL probe, a
power of a gap when the gap files an EHL probe, a frequency of a
gap firing an EHL probe, a unique identifier provided by an EHL
probe, or any other information that may be useful to the
electrical source in determining a remaining number of times a gap
may fire an EHL probe. When the electrical source determines that a
gap may no longer be able to file an EHL probe, the electrical
source may display a warning message indicating that maintenance or
replacement of the gap is necessary.
[0084] In some implementations, the electrical source may include
an internal power source such as a battery so that when external
power is not provided to the electrical source, the electrical
source is able to maintain the recorded information regarding the
gap. Additionally, in some implementations, the electrical source
may communicate with a computer so that the computer may retrieve
the recorded information stored at the electrical source for
purposes of record keeping, performance analysis, or trouble
shooting of the electrical source and/or an EHL probe.
[0085] It is intended that the foregoing detailed description be
regarded as illustrative rather than limiting, and that it be
understood that it is the following claims, including all
equivalents, that are intended to define the spirit and scope of
this invention.
* * * * *