U.S. patent application number 10/981096 was filed with the patent office on 2005-03-24 for helical device and method for aiding the ablation and assessment of tissue.
Invention is credited to Ryan, Thomas P..
Application Number | 20050065505 10/981096 |
Document ID | / |
Family ID | 29779258 |
Filed Date | 2005-03-24 |
United States Patent
Application |
20050065505 |
Kind Code |
A1 |
Ryan, Thomas P. |
March 24, 2005 |
Helical device and method for aiding the ablation and assessment of
tissue
Abstract
A helical needle is attached to a surgical probe to aid in the
insertion of the probe into a tissue mass. The tip of the helical
needle penetrates the tissue mass in advance of the tip of the
probe. The probe is rotated to push the helical shaft of the needle
into the tissue mass in the direction of rotation. As the helical
shaft advances into the tissue mass, the probe advances with it.
Rotating the probe in the opposite direction causes the helical
needle and probe to withdraw from the tissue mass. Rotation of the
probe and needle is more effective in penetrating rubbery and
calcified growths than the conventional method of pushing the
probe, and it enables the precise placement of the probe. The
helical needle also enables insertion of the probe in situations
where an inconvenient angle of entry makes it difficult to push the
probe along.
Inventors: |
Ryan, Thomas P.;
(Flemington, NJ) |
Correspondence
Address: |
RALPH W. SELITTO, JR.
C/O MCCARTER & ENGLISH, LLP
GATEWAY CENTER FOUR
100 MULBERRY STREET
NEWARK
NJ
07102
US
|
Family ID: |
29779258 |
Appl. No.: |
10/981096 |
Filed: |
November 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10981096 |
Nov 4, 2004 |
|
|
|
10184042 |
Jun 27, 2002 |
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Current U.S.
Class: |
606/27 ; 606/21;
606/41 |
Current CPC
Class: |
A61B 2017/06076
20130101; A61B 18/148 20130101; A61B 2017/00084 20130101; A61B
2018/1425 20130101; A61B 18/1477 20130101; A61B 17/06066
20130101 |
Class at
Publication: |
606/027 ;
606/021; 606/041 |
International
Class: |
A61B 018/04; A61B
018/02; A61B 018/14 |
Claims
1. A surgical device, comprising a surgical probe having a
substantially straight shaft section and a distal end; and a
helical needle having a distal end and a helical shaft section, the
helical needle being affixed to the probe such that the distal end
of the helical needle extends beyond the distal end of the probe
and the helical shaft section encompasses the shaft section of the
surgical probe.
2. The surgical device of claim 1, wherein the surgical probe
includes a source of thermal energy.
3. (cancelled).
4. The surgical device of claim 2, wherein the shaft section of the
surgical probe has a diameter in the range of about 2 mm to about 5
mm.
5. The surgical device of claim 4, wherein the helical shaft
section has the shape of a circular cylindrical helix, the helical
shaft section of the helical needle and the shaft section of the
surgical probe being aligned along a common axis.
6. The surgical device of claim 5, wherein the distal end of the
helical needle is terminated by a sharp tip for puncturing tissue,
the sharp tip being located on the common axis.
7. The surgical device of claim 2, wherein the helical needle has a
proximal end including an attachment section, said attachment
section being affixed to the shaft section of the surgical
probe.
8. The surgical device of claim 2, wherein the helical shaft
section of the helical needle has an exterior surface and at least
one thermal sensor exposed at the exterior surface.
9. The surgical device of claim 2, wherein the helical needle has
an interior channel and at least one thermal sensor within the
interior channel.
10. The surgical device of claim 1, wherein the helical needle is
made of a rigid material.
11. The surgical device of claim 1, wherein the helical needle is
made of a resilient material.
12. The surgical device of claim 1, wherein the helical needle is
made of a shape-memory alloy.
13. The surgical device of claim 1, wherein the surgical device has
a proximal end and a driving means for selectively rotating the
surgical device in a first rotational direction and in a second
rotational direction opposite to the first rotational direction,
the driving means being located at the proximal end of the surgical
device.
14. The surgical device of claim 13, wherein the driving means
comprises a handle including two opposed turning tabs.
15. The surgical device of claim 13, wherein the driving device
comprises a motorized device for rotating the surgical probe.
16. The surgical device of claim 13, wherein the driving device
comprises a ratchet assembly having a ratchet gear interconnected
with a movable handle, said ratchet assembly being adapted such
that the ratchet gear is rotated by movement of the handle.
17. (cancelled).
18. A method for inserting a surgical probe into a tissue mass, the
surgical probe having a substantially straight shaft section, a
distal end and a helical needle affixed to the surgical probe, the
helical needle having a distal end that extends beyond the distal
end of the probe, the method comprising the steps of puncturing the
tissue mass with the distal end of the helical needle; and rotating
the surgical device in a rotational direction such that the helical
needle advances into the tissue mass in the rotational direction,
thereby advancing the surgical probe in an axial direction, thereby
advancing the distal end of the surgical probe into the tissue
mass.
19. The method of claim 18, wherein the surgical probe has a
proximal end and a driving means for selectively rotating the
surgical probe in a first rotational direction and in a second
rotational direction opposite to the first rotational direction,
the driving means being located at the proximal end of the surgical
probe.
20. The method of claim 19, wherein the driving means is calibrated
for providing precise depth of penetration of the surgical probe.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a surgical device
to assess the performance of thermal treatment of diseased tissue.
More particularly, a surgical device utilizes a helical needle to
facilitate entry of a surgical treatment probe into the diseased
tissue with minimal difficulty. The diseased tissue may be
malignant or benign.
BACKGROUND OF THE INVENTION
[0002] The laparoscopic surgical technique of thermal ablation has
known applications as a minimally-invasive procedure for reducing
the volume of diseased tissue masses. In a typical thermal ablation
procedure, a probe carrying a thermal energy source is inserted
into the targeted tissue mass to a depth where the treatment will
be most effective. The tissue is then heated to a temperature at
which it coagulates, killing the treated tissue. The probe is
removed and the dead tissue is left in place to be resorbed by the
affected organ or tissue area. In some treatments, the probe is
cooled to a cryogenic temperature to freeze the tissue rather than
heat it.
[0003] The insertion and proper placement of the probe may become
problematic in the treatment of some tissue masses that comprise
rubbery and/or calcified tissue, such as fibroid growths of uterine
muscular tissue (i.e., myomas). Such tissue masses tend to resist
penetration and deflect the movement of the probe. The difficulty
of inserting the probe into the tissue mass increases in cases
where the laparoscopic opening affords an inconvenient angle of
entry for the probe.
[0004] Laparoscopic probes in the prior art, including thermal
probes, have been made in the form of thin needles, typically about
one (1) mm in diameter, such that the probe may be inserted with
relatively little resistance from the tissue mass. Unfortunately,
these small diameter probes bend easily when inserted into the
resisting tissue, resulting in misalignment within the tissue mass
and reducing the effectiveness of the thermal ablation treatment.
Moreover, straight, needle-like probes that are easily inserted are
susceptible to being accidentally displaced during the treatment
procedure. Thicker, more rigid probes would be less likely to bend,
but, because of their thickness, would be more difficult to insert
into a tissue mass than the thinner flexible probes.
[0005] There remains a need for a surgical assistance device that
aids the surgeon in inserting a laparoscopic probe into a resisting
tissue mass. Such a device should allow precise placement of the
probe within the tissue mass and resist accidental displacement. It
is desirable that the device aid the insertion of relatively thick
and rigid probes, in the range of 2-5 mm diameter. The device
should be usable for laparoscopic surgery, open surgery,
percutaneously or through natural body openings such as the
vagina.
SUMMARY OF THE INVENTION
[0006] In one aspect, the present invention comprises a helical
needle affixed to a laparoscopic probe so that the distal end of
the needle extends beyond the distal end of the probe. A preferred
embodiment of the invention comprises a helical needle having a
helical shaft section that encompasses the straight shaft of the
probe. More preferably, the helical needle is terminated by a sharp
tip, for puncturing tissue, located on a common axis with the
helical shaft section of the helical needle and the straight shaft
section of the probe.
[0007] Another aspect of the invention provides a means for
assessing the performance of thermal ablation of a tissue mass. In
a preferred embodiment of this aspect of the invention, a number of
thermal sensors are provided on the helical shaft section of a
helical needle affixed to a thermal treatment probe to measure the
temperature of the heated tissue.
[0008] In another aspect of the invention, the probe is provided
with a driving means to selectively rotate the probe in a direction
that drives the helical needle into a tissue mass or in an opposite
direction to wind the helical needle out of the tissue mass. One
preferred embodiment of this aspect of the invention provides a
handle with opposed turning tabs at the proximal end of the probe.
In another preferred embodiment, the rotation of the probe is
driven by a motorized device having a directional control switch. A
third preferred embodiment employs a manually operated ratchet
assembly with an independently movable ratchet and pawl to control
the direction of rotation of the ratchet gear that drives the
probe.
[0009] A fourth aspect of the invention includes methods for
inserting a laparoscopic probe into a tissue mass. The probe is
provided with a helical needle affixed thereto such that the distal
end of the needle extends past the distal end of the probe. In a
preferred method, the tissue mass is punctured with the distal end
of the needle and the probe is rotated such that the helical needle
advances into the tissue mass in the direction of rotation, thereby
advancing the probe into the tissue mass. In another preferred
embodiment, the probe is rotated by a driving means that is
calibrated to allow precise rotation of the probe.
[0010] The use of a helical needle in combination with a
laparoscopic probe enables the probe to penetrate a tissue mass by
rotation when the condition of the tissue or an inconvenient angle
of entry would make it difficult to insert the probe by the
conventional method of pushing it in an axial direction. The
assistance provided by the helical needle also enables the use of
probes having larger diameters than the one (1) mm probes that are
presently preferred. The combination of probe and helical needle
disclosed herein may be used advantageously in laparoscopic
surgery, open surgery, hysteroscopic surgery or for entry through
natural body orifices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a more complete understanding of the present invention,
reference is made to the following detailed description of the
present invention considered in conjunction with the accompanying
drawings, in which:
[0012] FIG. 1 is a perspective view of a surgical probe comprising
a laparoscopic probe and a helical needle attached thereto
constructed in accordance with a first exemplary embodiment of the
present invention;
[0013] FIG. 1A is a perspective view of the surgical probe of FIG.
1 illustrating an advanced entry of the probe and helical needle
within the tissue mass;
[0014] FIG. 2 is an exploded perspective view of the surgical probe
of FIG. 1 showing the laparoscopic probe and helical needle;
[0015] FIG. 3A is a perspective view of a surgical probe comprising
a laparoscopic probe and a helical needle attached thereto
constructed in accordance with a second exemplary embodiment of the
present invention illustrating the initial entry of the helical
needle into a tissue mass using a motorized device;
[0016] FIG. 3B is a perspective view of the surgical probe of FIG.
3A illustrating an advanced entry of the probe within the tissue
mass using a motorized device;
[0017] FIG. 4 is a perspective view of the helical needle of FIG.
3A showing a plurality of thermal sensors within the helical
needle;
[0018] FIG. 5 is a perspective view of the surgical probe of FIG. 1
with a ratchet-type screw assembly constructed in accordance with a
third exemplary embodiment of the present invention;
[0019] FIG. 6 is an exploded perspective view of the surgical probe
and ratchet-type screw assembly of FIG. 5;
[0020] FIG. 7 is an exploded perspective view of the ratchet-type
screw assembly of FIG. 5 showing elements of the assembly that
attach a pull lever to a ratchet mechanism;
[0021] FIG. 8 is a perspective view of the ratchet-type screw
assembly of FIG. 7 showing the pull level attached to the ratchet
mechanism;
[0022] FIG. 9 is a rear perspective view of the ratchet-type screw
assembly of FIG. 5 showing the pull lever attached to a handle
housing;
[0023] FIG. 10a is a sectional view of the ratchet-type screw
assembly of FIG. 7 showing the configuration of the ratchet
mechanism prior to actuation;
[0024] FIG. 10b is a sectional view of the ratchet-type screw
assembly of FIG. 10a showing the configuration of the ratchet
mechanism during actuation in a first rotational direction; and
[0025] FIG. 10c is a sectional view of the ratchet-type screw
assembly of FIG. 10b showing the ratchet mechanism configured for
actuation in a second rotational direction opposite to the first
rotational direction.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0026] Referring to FIGS. 1, 1A and 2, there is shown a probe 10 of
a type used in laparoscopic surgical procedures in combination with
a helical needle 12. The probe 10, as shown in FIG. 2, includes a
straight needle-like element 14 having a distal end 16, an
elongated shaft section 18, a proximal end 20, and an exterior wall
surface 22. The distal end 16 of needle-like element 14 is
terminated by a sharp tip 24 for entering a tissue mass 28 such as
a myoma, tumor or other unwanted growth (see FIG. 1A). The proximal
end 20 of needle-like element 14 includes a handle member 32 having
a pair of opposing turning tabs 34a, 34b attached to the exterior
wall surface 22 for use in driving the helical needle 12 and probe
10 into the tissue mass 28. The needle-like element 14 is made from
a rigid material, such as stainless steel, ceramic or a rigid
plastic such as teflon. The needle-like element 14 preferably has a
length in a range from about 20 mm to about 100 mm and a diameter
in a range of from about 2.0 mm to about 5.0 mm. The probe 10 may
have an energy source (not shown) connected thereto for providing
the thermal energy to ablate the targeted tissue mass 28. The
energy source may be in the form of RF electrodes, ultrasound
transducers, microwave transducers, cryogenic, or other energy
sources adapted to provide localized treatment of the tissue mass
28.
[0027] Referring to FIG. 2, the helical needle 12 has a distal end
36, a helically-shaped shaft section 38, a proximal end 40, an
exterior wall surface 42 and an interior channel 44. The distal end
36 of the helical needle 12 is terminated by a sharp tip 46 for
puncturing the tissue wall 26 and assisting the entry of helical
needle 12 into the tissue mass 28 (see FIG. 1A). The proximal end
40 of the helical needle 12 has an attachment section 48 for
affixing the helical needle 12 to the needle-like element 14. The
helical needle 12 is preferably made from a rigid material, such as
stainless steel, ceramic or a rigid plastic such as teflon, or of a
resilient "shape memory" metallic alloy, such as nitinol. The
helical needle preferably has a length in a range from about 25 mm
to about 105 mm, and a thickness in a range of from about 0.50 mm
to about 1.5 mm. The diameter of the helically-shaped shaft 38
should be sufficiently large to allow the helically-shaped shaft 38
to encompass the needle-like element 14.
[0028] The helically-shaped shaft 28 of the helical needle 12 is
disposed so as to encompass the needle-like element 14 of the probe
10 (see FIG. 1) with the sharp tip 46 of the helical needle 12
extending distally beyond the sharp tip 24 of the needle-like
element 14. The attachment section 48 of the helical needle 12 is
affixed to the elongated shaft section 18 such that the helical
needle 12 and needle-like element 14 cannot be moved in a
rotational or axial direction independently of each other. The
attachment section 48 may be affixed to the exterior wall surface
22 of the needle-like element 14 by means such as soldering,
welding, epoxy gluing, or laser welding, by insertion in a
receiving groove (not shown) on the elongated shaft 18, or by the
use of mechanical devices (e.g., connecting straps). Other means
for affixing the helical needle 12 to the needle-like element 14
will be obvious to those persons skilled in the mechanical
arts.
[0029] The helical needle 12 assists the entry of the probe 10 into
the tissue mass 28, as the following example illustrates. Referring
again to FIGS. 1 and 1A, the probe 10 is positioned with its distal
end 16 pointing toward the tissue mass 28 with the sharp tip 46 of
the helical needle 12 in contact with the tissue wall 26. The probe
10 is moved toward the tissue mass 28 such that sharp tip 46
penetrates the tissue wall 26 at entry point P. The probe 10 is
then rotated so as to wind the helically-shaped shaft 38 of the
helical needle 12 into the tissue mass 28. The helical shape of the
shaft 38 causes the helical needle 12 to advance into the tissue
mass 28 in a screw-like manner, i.e., the helical needle 12
advances in an axial direction by a predetermined distance for each
rotation of the shaft 38. Because the helical needle 12 is rigidly
affixed to the probe 10, the probe 10 also advances into the tissue
mass 28 as the helically-shaped shaft 38 is wound into the tissue
mass 28. The probe 10 may be removed from the tissue mass 28 by
rotating the probe 10 so as to wind the helically-shaped shaft 38
out of the tissue mass. The advancement or removal of the probe 10
may be assisted by applying an axially-directed force to the probe
10 as it is rotated.
[0030] A second exemplary embodiment 100 of the present invention
is shown in FIGS. 3A, 3B and 4. Elements shown in FIGS. 3A, 3B and
4 which correspond to the elements described above with reference
to FIGS. 1, 1A and 2 have been designated by corresponding
reference numbers increased by one hundred. The second exemplary
embodiment 100 is constructed and operates in the same manner as
the first exemplary embodiment 10, unless it is otherwise
stated.
[0031] Referring to FIGS. 3A, 3B and 4, the helical needle 112
includes a plurality of openings 150, each opening 150 being
adapted to receive a thermal sensor 152 therein. Each of the
thermal sensors 152 has a pair of conductive leads 154a, 154b
attached thereto for electrically activating the corresponding
thermal sensor 152. Preferably, the thermal sensors 152 are spaced
apart from each other by distances between about 2 mm and about 20
mm. As can be seen in FIG. 4, each of the thermal sensors 152 is
exposed at the exterior wall surface 142 of the helically-shaped
shaft 138 of helical needle 112 through the corresponding opening
150. The conductive leads 154a, 154b are routed within the interior
channel 144 from the corresponding thermal sensor 150 and the
proximal end 140 of the helical needle 112. Each of the thermal
sensors 152 and the corresponding conductive leads 154a, 154b may
be attached to openings 150 and to the interior channel 144 by
epoxy cement, soldering, laser welding, or other means of
attachment known in the arts. The helical needle 112 may be
fabricated by inserting the thermal sensors 152 and their
corresponding conductive leads 154a, 154b into the interior channel
144 of a straight pre-formed needle (not shown) having openings
150, then bending the straight needle into the helical
configuration of needle 112. The helical needle 12 may also be
encased in a shrink wrap layer (not shown) that is thin, durable
and biocompatible to protect the thermal sensors and prevent them
from interfering with the insertion of the helical needle 112 into
the tissue mass 126.
[0032] Referring again to FIGS. 3A and 3B, it can be seen that the
proximal end 120 of the probe 110 does not include a handle member
32 such as that included in the first embodiment 10 (see FIG. 1).
The proximal end 120 of the probe 110 includes a motorized device
156, which may include an AC, DC or stepper motor, for rotating the
probe 110 in a rotational direction M.sub.1 or an opposite
rotational direction M.sub.2, as required to insert or withdraw the
probe 110 and helical needle 112 from the tissue mass 128. The
motor 156 includes an on/off switch 158 to start or stop the motor
of motorized device 156 and a directional switch 160 to switch the
direction of rotation provided by the motorized device 156 between
rotational direction M.sub.1 and rotational direction M.sub.2.
[0033] The motorized device 156 assists the entry of the probe 110
into the tissue mass 128, as the following example shows. Referring
again to FIGS. 3A and 3B, the probe 110 is positioned with its
distal end 116 pointing toward the tissue mass 128 with the sharp
tip 146 of the helical needle 112 in contact with the tissue wall
126 at entry point P. The motorized device 156 is started by means
of on/off switch 158 and the directional switch 160 is set such
that the motorized device 156 rotates the probe 110 in the
rotational direction M.sub.1 which will wind the helically-shaped
shaft of the helical needle 112 into the tissue mass 128. The probe
110 is moved toward the tissue mass 128 such that the sharp tip 146
of the needle 112 penetrates the tissue wall 126 at entry point P.
The motorized device 156 then rotates probe 110 in the rotational
direction M.sub.1, thereby winding the helically-shaped shaft 138
into the tissue mass 128. With the distal end 116 of probe 110 at
the desired position within tissue mass 128, the motorized device
156 is stopped, and a thermal energy source (not shown) in probe
110 is energized. The temperature of the tissue mass 128 is
monitored by means of the thermal sensors 152 on the helical needle
112. The thermal energy source of probe 110 is de-energized after
the tissue mass 128 has been maintained at a sufficiently high
temperature for a sufficiently long time that a substantial portion
of the tissue mass 128 has coagulated. The directional switch 160
is set such that the motorized device 156 will rotate the probe 110
in the rotational direction M.sub.2 which will wind the
helically-shaped shaft 138 of the helical needle 112 out of the
tissue mass 128. The motorized device 156 is started by means of
the on/off switch 158 and the probe 110 is rotated in direction
M.sub.2, thereby winding the helically-shaped shaft 138 out of the
tissue mass 128 and withdrawing probe 110 from the tissue mass
128.
[0034] A third exemplary embodiment 200 of the present invention is
shown in FIGS. 5 and 6. Elements shown in FIGS. 5 and 6 which
correspond to the elements described above with reference to FIG. 1
have been designated by corresponding reference numbers increased
by two hundred. Elements shown in FIGS. 5 and 6 that correspond to
elements described above with respect to FIG. 4 have been
designated by corresponding reference numbers increased by one
hundred. The third exemplary embodiment 200 is constructed and
operates in the same manner as the first exemplary embodiment 10,
unless it is otherwise stated.
[0035] As can be seen in FIG. 5, the proximal end 220 of the probe
210 does not include a handle member 32 such as that included in
the probe 10 of the first embodiment 10 (see FIG. 1). The proximal
end 220 includes a ratchet-type screw assembly 262 for rotating the
probe 210 in a rotational direction M.sub.1 or an opposite
rotational direction M.sub.2, as required to insert or withdraw the
probe 210 and helical needle 212 from the tissue mass 228.
[0036] Referring to FIGS. 5-10c, the ratchet-type screw assembly
262 includes a ratchet-gear sub-assembly 264 having a reversing
lever 266, a ratchet spring 268, a pawl element 270, a ratchet
element 272, a gear member 274 and a hollow shaft 276. The hollow
shaft 276 includes a distal end 278, a proximal end 280 and an
interior channel 282. The gear member 274 includes an axial opening
284 for receiving the proximal end 280 of shaft 276. The gear
member 274 also includes a plurality of gear teeth 286 for engaging
the pawl and ratchet elements 270, 272 The ratchet spring 268
includes an outer pair of spring arms 288a, 288b and an inner pair
of spring arms 290a, 290b. Ratchet spring 268 also includes an
upper wall 296 having opposing perimeter sides 292, 294 and an oval
opening 298. The spring arms 288a, 290a are integrally attached to
perimeter side 292 and the spring arms 288b, 290b are integrally
attached to the perimeter side 294 (see FIGS. 6 and 7). Reversing
lever 266 includes a tab element 300 that is adapted to be received
within the oval opening 298 of the upper wall 296 of the ratchet
spring 268.
[0037] Continuing to refer to FIGS. 5-10c, the pawl element 270
includes a pair of opposing gear engagement tabs 302a, 302b for
interacting with the outer pair of spring arms 288a, 288b,
respectively, and with the gear teeth 286 of the gear member 274 so
as to prevent the gear member 274 from rotating against the
selected rotational direction M.sub.1 or M.sub.2. The pawl element
270 also includes a centrally located pivot opening 304. The
ratchet element 272 includes a pair of opposing gear engagement
tabs 306a, 306b for interacting with the inner pair of spring arms
290a, 290b, respectively, and with the gear teeth 286 of the gear
member 270 to drive the gear member in the selected rotational
direction M.sub.1 or M.sub.2. The ratchet element 272 also includes
a centrally located pivot opening 308. The reversing lever 266
includes a lever arm 310 and a cam element 312, wherein the tab
element 300 is located in a position off-set from the center of the
cam element 312 (see FIG. 6), and the lever arm 310 is located in a
position off-set relative to the position of tab element 300. The
cam element 312 of reversing lever 266 is used to shift the ratchet
spring 268 in a side-to-side movement as reversing lever 266 is
moved between a first position and a second position.
[0038] Referring now to FIGS. 6-9, the ratchet-type screw assembly
262 also includes a handle member 314, a pull lever 316, a return
spring 318 and a guide bracket 320. The handle member 314 includes
a handle section 322 and an integrally attached housing section 324
for holding and encasing the sub-assembly 264 therein. The housing
section 324 includes an upperwall 326 having a mounting opening 328
therein, side walls 330, 332, a front wall 334 having a rectangular
opening 336 therein, a rear wall 338 having a rectangular opening
340 therein, and a rear housing cover 342. The rectangular opening
340 receives the ratchet gear sub-assembly 264 therethrough and the
rear housing cover 342 thereon. The mounting opening 328 of upper
wall 326 receives the cam element 312 therethrough, such that the
cam element 312 may alternately bias the spring arms 288a, 290a or
the spring arms 288b, 290b of the ratchet spring 268 towards the
gear member 274 as the reversing lever 266 is moved alternately
between a first position and a second position. When the reversing
lever 266 is in the first position, the cam element 312 also biases
the spring arm 288a away from the side wall 330 of housing section
324, but does not bias spring arm 290a. When the reversing lever
266 is in the second position, the cam element 312 biases the
spring arm 290b away from the side wall 332 of the housing section
324. The side wall 330 includes a hinge cover 344a and side wall
332 includes a hinge cover 344b, each hinge cover 344a, 344b being
integrally connected to the corresponding side wall 330, 332 (see
FIGS. 5 and 6). The housing cover 342 has a centrally located
opening 346 for receiving an electrical cable 348 having a distal
end 350 and a proximal end 352. The distal end 350 of the
electrical cable 348 is inserted through the opening 346 of the
housing cover 342 and the interior channel 282 of shaft 276. The
distal end 350 of the electrical cable 348 is electrically
connected to the proximal end 220 of probe 210 for providing
electrical energy to the thermal energy source (not shown) within
probe 210, and is electrically connected to the proximal end 240 of
helical needle 212 for providing electrical energy to the thermal
sensors 252 within helical needle 212. The housing cover 342 also
includes an integrally attached pivot pin 354 positioned on an
inner wall surface 356 of housing cover 342. The pivot pin 354 of
housing cover 342 is received within the pivot opening 304 of pawl
element 270, allowing the pawl element 270 to move independently
from the ratchet element 272.
[0039] As shown in FIGS. 5-10a, the return spring 318 includes a
first spring arm 358 and a second spring arm 360. The pull lever
316 includes a front grooved channel 362 having a distal end 364
and a proximal end 366, a front wall 368 and side walls 370, 372.
Each of the side walls 370, 372 includes a tab pin 374a, 374b,
respectively, thereon. Each of the side walls 370, 372 further
includes a hinge pin 376a, 376b, respectively, thereon. Each of the
hinge pins 376a, 376b are received within the corresponding hinge
cover 344a, 344b, respectively, for connecting the pull lever 316
to the handle member 314 (see FIGS. 5, 6 and 10a). Referring to
FIGS. 8 and 9, the first spring arm 358 of return spring 318 is
positioned within the distal end 364 of the grooved channel 362 and
the second spring arm 360 of return spring 318 is received within
opening 336 on the front wall 334 of housing section 324 of handle
member 314, in order to flex the pull lever 316 to an opened
configuration S.sub.1 relative to the handle section 322 of handle
member 314. The guide bracket 320, as depicted in FIGS. 7 and 8,
includes an inner wall surface 378 having an integrally attached
pivot pin 380 thereon, being adjacent to an upper edge 382 of guide
bracket 320. The guide bracket 320 also includes a pair of grooved
notches 382a, 382b each being centrally positioned on side edges
384, 386, respectively. The pivot pin 380 of guide bracket 320 is
received within the pivot opening 308 of ratchet element 272,
allowing the ratchet element 272 to move independently from the
pawl element 270. Each of the tab pins 374a, 374b of pull lever 316
are received within a corresponding grooved notch 382a, 382b on
guide bracket 320, respectively, thus connecting the guide bracket
320 to the pull lever 316 and to handle member 314, as well as to
the ratchet element 272 of the ratchet-gear sub-assembly 264 (see
FIGS. 8, 9 and 10a). Referring again to FIGS. 7, 8 and 9, the
return spring 318 interconnects the pull lever 316 with the guide
bracket 320 and the housing section 324 of handle member 314, such
that, when the pull lever 316 is squeezed toward the handle section
322 of handle member 314 (i.e, to position S.sub.2), the pull lever
316 engages the ratchet-gear sub-assembly 264. The ratchet-gear
sub-assembly 264 then advances and turns gear member 274 and shaft
276 in rotational direction M.sub.1 or in rotational direction
M.sub.2, depending upon the position of reversing lever 266 and the
resulting bias on spring 268 (see FIGS. 10a-10c).
[0040] Referring now to FIGS. 5 and 6, the ratchet-type screw
assembly 262 further includes a sliding sleeve 388 having an
interior channel 390 for slidably receiving shaft 276 therein, and
a union connector 392 having an axial opening 394 for attaching and
receiving the proximal end 220 of the probe 210 and the proximal
end 240 of the helical needle 212 and connecting the respective
proximal ends 220, 240 to the distal end 278 of shaft 276 (see FIG.
5).
[0041] In operation, the ratchet-type screw assembly 262 may be
used to rotate the probe 210 and the helical needle 212 so as to
insert or withdraw the probe 210 and the helical needle 212 from
the tissue mass 228. The following example illustrates the
application of the third embodiment 200 with particular attention
to the operation of the ratchet-type screw assembly 264.
[0042] Referring now to FIGS. 10a, 10b, which show the ratchet-gear
sub-assembly 264 as configured to rotate the probe 210 in the
rotational direction M.sub.1, it can be seen that the reversing
lever 266 is set in a first position so that cam element 312 of
reversing lever 266 biases the spring arms 288a, 290a towards the
gear member 274. The spring arm 288a contacts the gear engagement
tab 302a of pawl element 270, thereby moving the gear engagement
tab 302a such that it engages one of the gear teeth 286 of gear
member 274. By engaging gear tooth 286, gear engagement 302a
prevents the backward rotation of gear member 274 (i.e., rotation
in direction M.sub.2). At the same time, the spring arm 290a
contacts the gear engagement tab 306a of ratchet element 272,
thereby moving the gear engagement tab 306a to engage one of the
gear teeth 286 of gear member 274. The gear engagement tab 306a
engages its corresponding gear tooth 286 such that pushing ratchet
element 272 toward gear member 274 will cause gear member 274 to
rotate in rotational direction M.sub.1. The spring force F from the
spring arms 288a, 290a keeps the pawl and ratchet elements 270,
272, respectively, in contact with the gear member 274 at all
times. The direction of rotation may be changed to rotational
direction M.sub.2 by setting reversing lever 266 to a second
position (see FIG. 10c) which causes the cam element 312 to bias
the spring arms 288b, 290b of the ratchet spring 268 towards the
gear member 274. The spring arm 288b contacts the gear engagement
tab 302b of pawl element 270, thereby moving the gear engagement
tab 302b such that it engages one of the gear teeth 286 of gear
member 274 to prevent the backward rotation of gear member 274
(i.e., rotation in direction M.sub.1). The spring arm 290b contacts
the gear engagement tab 306b of ratchet element 272, thereby moving
the gear engagement tab 306b to engage one of the gear teeth 286 of
gear member 274. Because the gear engagement tab 306b is on the
opposite side of the gear member 274 from engagement tab 306a,
pushing ratchet element 272 toward gear member 274 will cause gear
member 274 to rotate in the opposite rotational direction
M.sub.2.
[0043] For the purpose of this illustrative example, it is
understood that assembly 262 was set to rotate probe 210 in
rotational direction M.sub.1 by setting reversing lever 266 to a
first position prior to pointing the distal end 216 of the probe
210 with the sharp tip 246 of helical needle 212 in contact with
the tissue wall 226. The operator then proceeds to squeeze the pull
lever 316 towards the handle section 322 from a first position
S.sub.1 to a second position S.sub.2 several times, thereby pushing
ratchet element 272 toward gear member 274 by means of the
interconnected elements handle 316 and guide plate 320. The
rotation of the probe 210 causes the helically-shaped shaft 238 of
helical needle 212 to wind into the tissue mass 228, thereby
advancing the probe 210 and the helical needle 212 into the tissue
mass 228. After completion of the thermal treatment, the operator
then sets the reversing lever in a second position, reversing the
direction of rotation, and squeezes the pull lever 316 towards the
handle section 322, as described above. The probe 210 is rotated in
rotational direction M2, thereby winding helically-shaped shaft 238
out of the tissue mass 228 such as to remove the probe 210 and the
helical needle 212 from the tissue mass 228.
[0044] The use of a helical needle 12 in combination with a probe
10, as described above, presents numerous advantages compared to
the use of the probe 10 by itself. For example, the relatively thin
distal end 36 of helical needle 12 penetrates more readily into the
rubbery or calcified tissue of a myoma, tumor or other unwanted
growth (i.e, tissue mass 28) than does the thicker distal end 16 of
probe 10. The helical shape of the shaft 38 of the helical needle
12 causes the helical needle 12 to advance into the tissue mass 28
in an axial direction as it is rotated, pulling the probe 10 in the
same direction. The probe 10 can, therefore, be more readily
advanced into the tissue mass 28 by rotation when the angle of
entry or the condition of the tissue would make it difficult to
insert the probe 10 by pushing it in an axial direction. Under
typical circumstances, rotational force alone will be sufficient to
drive the probe into or out of the tissue mass. The assistance
provided to the entry of probe 10 also enables the use of probes
having larger diameters than the one (1) mm probes that are
presently preferred. Another advantage may be realized because the
helical shape of the shaft 38 of the helical needle 12 causes the
helical needle 12 to resist being moved within the tissue mass 28
by forces applied in the axial or lateral directions. This
resistance to movement acts to stabilize the position of probe 10
within the tissue mass 28 during treatment, reducing the likelihood
that the probe 10 will be accidentally withdrawn from the intended
treatment location. Moreover, the geometry of the helically-shaped
shaft 38 causes the probe 10 to be advanced by a predetermined
distance with each complete rotation of the affixed
helically-shaped shaft 38. This geometrical relationship allows the
depth to which the probe 10 penetrates the tissue mass 28 to be
controlled by precisely rotating the probe 10 and helical needle
12. Such precise rotation may be provided by the ratchet-type screw
device 262 or other mechanical devices adapted to rotate the probe
10 by predetermined amounts. The helical needle 12 may also serve
as a carrier for thermal sensors for monitoring the temperature of
the tissue mass 28 during thermal treatment, and, thereby,
providing a means to control the temperature of the tissue mass 28
and the progress of the treatment.
[0045] The combination of probe and helical needle disclosed herein
is not limited to uses in laparoscopic surgery. It may also be used
advantageously in open surgery, hysteroscopic surgery or for entry
through natural body orifices such as the mouth, the ear, the
vagina, the uterus, the rectum, or the penis.
[0046] It will be understood that the embodiments described herein
are merely exemplary and that a person skilled in the art may make
many variations and modifications without departing from the spirit
and scope of the invention. For example, the helical needle 12 may
be solid instead of having an interior channel 44. The helical
needle 112 may also be solid and the thermal sensors 152 and their
respective conductive leads 154a and 154b attached to the exterior
wall surface 142 of the helical shaft section 138 of helical needle
112. Alternatively, in embodiments where the helical needle 112 has
an interior channel 144, the openings 150 may be omitted and the
thermal sensors 152 and conductive leads 154a, 154b embedded in a
plastic rod or tube within the interior channel 144. The helical
needle 112 may also be used as a carrier for sensors other than the
thermal sensors 152. The probe 10 may be provided with means for
rotatably inserting and removing the probe 10 other than the motor
device 156 or ratchet-type screw assembly 262. All such variations
and modifications, including those discussed above, are intended to
be included within the scope of the invention as defined in the
appended claims.
* * * * *