U.S. patent application number 13/660495 was filed with the patent office on 2013-03-07 for hammer toe implant.
This patent application is currently assigned to WRIGHT MEDICAL TECHNOLOGY, INC.. The applicant listed for this patent is Wright Medical Technology, Inc.. Invention is credited to Dinesh V. Koka, Wesley Reed.
Application Number | 20130060295 13/660495 |
Document ID | / |
Family ID | 45065050 |
Filed Date | 2013-03-07 |
United States Patent
Application |
20130060295 |
Kind Code |
A1 |
Reed; Wesley ; et
al. |
March 7, 2013 |
HAMMER TOE IMPLANT
Abstract
An implant is disclosed including an elongate threaded portion
and a blade portion extending from the elongate threaded portion.
The blade portion has a taper terminating at a point.
Inventors: |
Reed; Wesley; (Memphis,
TN) ; Koka; Dinesh V.; (Memphis, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wright Medical Technology, Inc.; |
Arlington |
TN |
US |
|
|
Assignee: |
WRIGHT MEDICAL TECHNOLOGY,
INC.
Arlington
TN
|
Family ID: |
45065050 |
Appl. No.: |
13/660495 |
Filed: |
October 25, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13086136 |
Apr 13, 2011 |
|
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13660495 |
|
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|
61350665 |
Jun 2, 2010 |
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Current U.S.
Class: |
606/319 ;
623/21.19 |
Current CPC
Class: |
A61B 17/8891 20130101;
A61B 17/8883 20130101; A61B 17/862 20130101; A61F 2/4225 20130101;
A61B 17/7291 20130101; A61F 2002/4233 20130101; A61F 2002/4228
20130101; A61F 2002/30622 20130101 |
Class at
Publication: |
606/319 ;
623/21.19 |
International
Class: |
A61B 17/86 20060101
A61B017/86; A61F 2/42 20060101 A61F002/42 |
Claims
1. An implant for treating hammer toe, the implant comprising: a
threaded portion; and a blade portion extending from the threaded
portion and including a plurality of serrated edges that extend
along opposed sides of the blade portion.
2. The implant of claim 1, wherein the blade portion extends from
the threaded portion at angle with respect to an axis defined by
the threaded portion.
3. The implant of claim 2, wherein the angle is between zero and 45
degrees.
4. The implant of claim 2, wherein the angle is between five and 15
degrees.
5. The implant of claim 1, wherein a thickness dimension of the
blade portion of the implant is less than a width dimension of the
blade portion of the implant.
6. The implant of claim 1, wherein a diameter of the threaded
portion is between 1.6 mm and 2.4 mm.
7. The implant of claim 1, wherein a diameter of the threaded
portion is 2 mm.
8. A system, comprising: an implant for treating hammer toe, the
implant including a threaded portion, and a blade portion extending
from the elongate threaded portion, the blade portion including a
plurality of serrated edges that extend along opposed sides of the
blade portion; and a driving adapter including a body defining an
opening at a first end that is sized and configured to receive the
blade portion of the implant, a second end of the body is sized and
configured to engage a driving tool for driving the implant into a
bone.
9. The system of claim 8, wherein the blade portion of the implant
extends from the threaded portion at an angle with respect to an
axis defined by the threaded portion.
10. The system of claim 9, wherein the angle is between zero and 45
degrees.
11. The system of claim 9, wherein the angle is between five and 15
degrees.
12. The system of claim 8, wherein a thickness dimension of the
blade portion of the implant is less than a width dimension of the
blade portion of the implant.
13. The system of claim 8, wherein a diameter of the threaded
portion of the implant is between 1.6 mm and 2.4 mm.
14. The system of claim 8, wherein a diameter of the threaded
portion of the implant is 2 mm.
15. An implant for treating hammer toe, the implant comprising: a
threaded portion; and a blade portion extending from the threaded
portion and including a plurality of serrated edges that extend
along opposed sides of the blade portion, wherein the blade portion
extends from the threaded portion at angle with respect to an axis
defined by the threaded portion, and wherein a thickness dimension
of the blade portion of the implant is less than a width dimension
of the blade portion of the implant.
16. The implant of claim 15, wherein the angle is between zero and
45 degrees.
17. The implant of claim 15, wherein the angle is between five and
15 degrees.
18. The implant of claim 15, wherein a diameter of the threaded
portion is between 1.6 mm and 2.4 mm.
19. The implant of claim 15, wherein a diameter of the threaded
portion is 2 mm.
20. The implant of claim 15, wherein the blade portion is tapered.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Patent
Application No. 13/086,136, filed Apr. 13, 2011, which claims
priority to U.S. Provisional Patent Application Ser. No.
61/350,665, which was filed on Jun. 2, 2010, the entireties of
which are herein incorporated by reference.
FIELD OF DISCLOSURE
[0002] The disclosed system and method relate implants. More
specifically, the disclosed system and method relate to installing
an implant for treating hammer toe.
BACKGROUND
[0003] Hammer toe is a deformity of the toe that affects the
alignment of the bones adjacent to the proximal interphalangeal
(PIP) joint. Hammer toe can cause pain and can lead to difficulty
in walking or wearing shoes. A hammer toe can often result in an
open sore or wound on the foot. In some instances, surgery may be
required to correct the deformity by fusing one or both of the PIP
and distal interphalangeal (DIP) joints.
[0004] The most common corrective surgery includes the placement of
a pin or rod in the distal, middle, and proximal phalanxes of the
foot to fuse the PIP and DIP joints. The pin or rod is cut at the
tip of the toe, externally of the body. A plastic or polymeric ball
is placed over the exposed end of the rod, which remains in the
foot of the patient until the PIP and/or DIP joints are fused in
approximately 6 to 12 weeks. This conventional treatment has
several drawbacks such as preventing the patient from wearing
closed toe shoes while the rod or pin is in place, and the plastic
or polymeric ball may snag a bed sheet or other object due to it
extending from the tip of the toe resulting in substantial pain for
the patient.
[0005] Another conventional implant includes a pair of threaded
members that are disposed within adjacent bones of a patient's
foot. The implants are then coupled to one another through
male-female connection mechanism, which is difficult to install in
situ and has a tendency to separate.
[0006] Yet another conventional implant has body including an oval
head and a pair of feet, which are initially compressed. The
implant is formed from nitinol and is refrigerated until it is
ready to be installed. The head and feet of the implant expand due
to the rising temperature of the implant to provide an outward
force on the surrounding bone when installed. However, the
temperature sensitive material may result in the implant deploying
or expanding prior to being installed, which requires a new implant
to be used.
[0007] Accordingly, an improved implant for treating hammer toe is
desirable.
SUMMARY
[0008] An implant is disclosed including an elongate threaded
portion and a blade portion extending from the elongate threaded
portion. The blade portion has a taper terminating at a point.
[0009] A method is also disclosed in which an incision is formed to
gain access to a joint between first and second bones. The first
and second bones are flexed such that the bones are disposed at an
angle from one another. A threaded portion of an implant is
advanced into the first bone. The implant includes a blade portion
extending from the elongate threaded portion. The second bone is
repositioned such that a middle of the second bone is approximately
aligned with the blade portion of the implant. The second bone is
forced into engagement with the blade portion of the implant.
[0010] A surgical assembly is disclosed comprising an implant
having an elongate body and a driving assembly. The implant
includes a threaded end and a blade end extending from the threaded
end. The blade end tapers along its thickness and its width to a
point and includes a plurality of serrated edges. The driving
assembly includes a handle, a driving rod extending from the
handle, and an adapter coupled to an end of the driving rod. The
adapter has a body defining a slot at one end that is sized and
configured to receive the blade end of the implant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features and advantages of the present
invention will be more fully disclosed in, or rendered obvious by
the following detailed description of the preferred embodiments of
the invention, which are to be considered together with the
accompanying drawings wherein like numbers refer to like parts and
further wherein:
[0012] FIG. 1 is an isometric view of one example of an improved
hammer toe implant;
[0013] FIG. 2 is a top side view of the hammer toe implant
illustrated in FIG. 1;
[0014] FIG. 3 is a sectional view of the hammer toe implant taken
along line 3-3 in FIG. 2;
[0015] FIG. 4 is an end on view of the hammer toe implant taken
along line 4-4 in FIG. 2;
[0016] FIG. 5 is a side view of another example of a hammer toe
implant;
[0017] FIG. 6 is a top side view of the hammer toe implant
illustrated in FIG. 5;
[0018] FIG. 7 is a side view of one example of a driving adapter
for use with the hammer toe implants illustrated in FIGS. 1 and
6;
[0019] FIG. 8 is an end view of the driving adapter illustrated in
FIG. 7;
[0020] FIG. 9 is a side view of another example of a driving
adapter for use with the hammer toe implants illustrated in FIGS. 1
and 6;
[0021] FIG. 10 is an end view of the driving adapter illustrated in
FIG. 9;
[0022] FIG. 11 is an assembly view of a hammer toe implant engaged
by a driving adapter;
[0023] FIGS. 12A and 12B illustrate the middle and proximal
phalanxes of a foot being resected;
[0024] FIG. 13 illustrates a hammer toe implant being driven into a
proximal phalanx;
[0025] FIG. 14 illustrates a middle phalanx being drilled or
broached;
[0026] FIG. 15 illustrates a blade of a hammer toe implant
extending from the proximal phalanx with the middle phalanx having
been drilled or broached;
[0027] FIG. 16 illustrates a hammer toe implant installed in the
middle and proximal phalanxes;
[0028] FIG. 17 illustrates another example of a driving assembly
for installing an implant;
[0029] FIG. 18 illustrates side view of the driving assembly
illustrated in FIG. 17;
[0030] FIG. 19 is an isometric view of an adapter of the driving
assembly illustrated in FIG. 17;
[0031] FIG. 20 is an end view of the adapter illustrated in FIG.
19;
[0032] FIG. 21 is a cross-sectional view of the adapter taken along
line 21-21 in FIG. 20;
[0033] FIG. 22 is a cross-sectional view of the adapter taken along
line 22-22 in FIG. 20;
[0034] FIG. 23 is a plan view of the driving rod of the driving
assembly illustrated in FIG. 17;
[0035] FIG. 24 is a cross-sectional view of the driving rod taken
along line 24-24 in FIG. 23;
[0036] FIG. 25 is a cross-sectional view of the fin of the driving
rod taken along line 25-25 in FIG. 23;
[0037] FIG. 26 is a plan view of driving assembly illustrated in
FIG. 17 without the o-ring;
[0038] FIG. 27 is a cross-sectional view of the handle taken along
line 27-27 in FIG. 26;
[0039] FIGS. 28A and 28B illustrate the middle and proximal
phalanxes of a foot being resected;
[0040] FIGS. 29A and 29B illustrate an implant coupled to the
adapter of the driving assembly illustrated in FIG. 17;
[0041] FIG. 30 illustrates a hammer toe implant being driven into a
proximal phalanx;
[0042] FIG. 31 illustrates a middle phalanx being drilled or
broached;
[0043] FIG. 32 illustrates a blade of a hammer toe implant
extending from the proximal phalanx with the middle phalanx having
been drilled or broached; and
[0044] FIG. 33 illustrates a hammer toe implant installed in the
middle and proximal phalanxes.
DETAILED DESCRIPTION
[0045] This description of preferred embodiments is intended to be
read in connection with the accompanying drawings, which are to be
considered part of the entire written description. The drawing
figures are not necessarily to scale and certain features of the
invention may be shown exaggerated in scale or in somewhat
schematic form in the interest of clarity and conciseness. In the
description, relative terms such as "horizontal," "vertical," "up,"
"down," "top," and "bottom" as well as derivatives thereof (e.g.,
"horizontally," "downwardly," "upwardly," etc.) should be construed
to refer to the orientation as then described or as shown in the
drawing figure under discussion. These relative terms are for
convenience of description and normally are not intended to require
a particular orientation. Terms including "inwardly" versus
"outwardly," "longitudinal" versus "lateral," and the like are to
be interpreted relative to one another or relative to an axis of
elongation, or an axis or center of rotation, as appropriate. Terms
concerning attachments, coupling, and the like, such as "connected"
and "interconnected," refer to a relationship wherein structures
are secured or attached to one another either directly or
indirectly through intervening structures, as well as both movable
or rigid attachments or relationships, unless expressly described
otherwise. The term "operatively connected" is such an attachment,
coupling or connection that allows the pertinent structures to
operate as intended by virtue of that relationship.
[0046] FIG. 1 illustrates one example of an improved implant 100
for treating hammer toe. As shown in FIG. 1, implant 100 includes a
threaded portion 102 and a blade portion 104, which are connected
together at an engagement portion 106. Implant 100 may have a
substantially linear geometry having an overall length of
approximately 19 mm (approximately 0.75 inches). In some
embodiments, such as the one illustrated in FIGS. 5 and 6, blade
portion 104 may be disposed at angle with respect to a longitudinal
axis defined by the threaded portion 102. The angle may be between
zero and 45 degrees, and more particularly between approximately
five and fifteen degrees, although one skilled in the art will
understand that implant 100 may have other dimensions and be
provided in different sizes. For example, implant 100 may be
provided in lengths of 16 mm and 22 mm, to name a few potential
lengths.
[0047] Threaded portion 102 may include a plurality of threads 108
disposed along its entire length, which may be approximately 13 mm
(approximately 0.5 inches). The tip 110 of threaded portion 102 may
be pointed to facilitate the advancement of threads 108 into bone.
Threads 108 may have a maximum outer diameter of approximately 2 mm
(approximately 0.08 inches), although one skilled in the art will
understand that thread portion 102 may have other dimensions and be
configured to be received within a phalanx bone of a person. For
example, threads may have an outer diameter of approximately 2.4 mm
and 1.6 mm, to name a few potential possibilities.
[0048] As best seen in FIG. 3, blade portion 104 includes a
plurality of serrated edges 112 on its top and bottom sides 114,
116. Blade portion 104 may have a width that is greater than its
thickness as best seen in FIGS. 2 and 4. For example, blade portion
104 may have a width of approximately 0.4 centimeters
(approximately 0.16 inches) and a thickness of approximately 0.1
centimeters (approximately 0.04 inches) each of which taper to
point 118.
[0049] Blade portion 104 may have a substantially rectangular
cross-sectional area as illustrated in FIG. 4, although one skilled
in the art will understand that blade portion 104 may have other
cross-sectional geometries.
[0050] Engagement portion 106 may include a pair of protrusions 120
extending from opposite sides of implant 100 and having rounded
outer edges 122. The sides 124 of protrusions 120 may be
substantially parallel with each other as shown in FIG. 4.
[0051] Implant 100 is configured to be installed using a driving
adapter 200 such as the one illustrated in FIGS. 7-10. The driving
adapter 200 has an elongate body 202 having a proximal end 204 and
a distal end 206. Body 202 of driving adapter 200 may have a
circular cross-sectional geometry, although one skilled in the art
will understand that body 202 may have other cross-sectional
geometries including, but not limited to, triangular, rectangular,
pentagonal, and hexagonal to name a few.
[0052] Proximal end 204 may be substantially solid and have a
rounded tip 208. Distal end 206 may define a slot 210 sized and
configured to receive blade portion 104 of implant 100 therein.
Slot 210 may have a rectangular cross-sectional geometry and have a
depth that is sufficient to receive the entire blade portion 104 of
implant 100 such that distal edges 212 of slot 210 contact
protrusions 120 of engagement portion 106. However, one skilled in
the art will understand that slot 210 may have other
cross-sectional geometries and dimensions. Slot 210 may extend
through side walls 214 of body 202 as shown in FIGS. 7 and 8, or
side walls 214 may completely enclose slot 210 as shown in FIGS. 9
and 10.
[0053] If the driving adapter 200 is to be used with an implant 100
having a substantially linear lengthwise geometry such as the
implant 100 illustrated in FIGS. 1-5, then slot 210 may extend in a
direction that is substantially parallel to an axis defined by body
202 of driving adapter 200. If driving adapter 200 is to be used
with an implant 100 having a blade portion 104 that extends at an
angle with respect to an axis defined by elongate threaded portion
102 such as the implant illustrated in FIGS. 5 and 6, then slot 210
may extend from distal edges 212 at an angle with respect to an
axis defined by the length of body 202 such that elongate threaded
portion 102 of implant 100 is linearly aligned with body 202 of
driving adapter 200 as shown in FIG. 11. For example, if blade
portion 104 of implant 100 extends at a ten degree angle with
respect to an axis defined by elongate threaded portion 102, then
slot 210 of driving adapter 200 may extend at a ten degree angle
with respect to a longitudinal axis defined by body 202 such that
threaded portion 102 of implant 100 and body 202 of driving adapter
200 are substantially linearly aligned.
[0054] A method of installing implant 100 in the proximal
interphelangeal joint (PIP) 300 is described with reference to
FIGS. 12A-16. However, one skilled in the art will understand that
the technique for installing the implant 100 may be applied to
other joints such as, for example, the distal interphelangeal (DIP)
joint between middle phalanx 304 and distal phalanx 306. As shown
in FIGS. 12A and 12B, an incision is made to open the PIP joint 300
and a cutting tool 400 having a blade 402 may be used to resect
adjacent faces of proximal phalanx 302 and middle phalanx 304. The
resected surfaces of proximal phalanx 302 and middle phalanx 304
may be debrided as understood by one skilled in the art.
[0055] Blade portion 104 of implant 100 may be disposed within slot
210 of driving adapter 200 as shown in FIG. 11, and the body 202 of
driving adapter 200 may be secured in a chuck 412 of a drill 410 or
other driving instrument as shown in FIG. 13. Drill 410 or other
driving instrument is used to drive the threaded portion 102 of
implant 100 into the resected surface of proximal phalanx 302. With
the threaded portion 102 of implant 100 disposed within proximal
phalanx 302, driving adapter 200 may be disengaged from blade
portion 104 of implant 100.
[0056] Middle phalanx 304 may be predrilled or broached using drill
410 to create a hole 308 as shown in FIGS. 14 and 15. The
predrilled or broached middle phalanx 304 is then repositioned such
that the predrilled hole or broach 308 aligns with the blade
portion 104 of implant 100. The middle phalanx 304 is then pressed
into engagement with the blade portion 104 as shown in FIG. 16.
Serrated edges 112 of blade portion 104 help to maintain the
engagement between middle phalanx 304 and blade portion 104 of
implant 100.
[0057] FIGS. 17-27 illustrate another embodiment of a driver
assembly 500 for installing an implant into bone. As shown in FIGS.
17 and 18, driver assembly 500 includes an adapter 502 coupled to a
driving rod 516 onto which a handle 534 is over-molded or otherwise
coupled. Adapter 502 includes a body 504 with a substantially
rectangular side profile comprising side walls 506-1, 506-2, 506-3,
and 506-4 (collectively referred to as "side walls 506") and a pair
of end walls 508-1, 508-2 (collectively referred to as "end walls
508") having a substantially square geometry as best seen in FIGS.
19-22.
[0058] Body 504 defines a recess 510 along the length of side walls
506. Recess 510 is dimensioned such that an o-ring 544 (FIGS. 17
and 18) may be received therein. Additionally, recess 510 is
located along side walls 506 at a distance from end walls 508 such
that recess 510 is aligned with a valley 126 of serrated edges 112
along the top and bottom sides 114, 116 of blade portion 104.
[0059] End wall 508-1 defines an aperture 512 having a geometry
that complements the cross-sectional geometry of blade portion 104
of implant 100. For example, if implant 100 has a straight blade
portion 104 as illustrated in FIG. 2, then aperture 512 may extend
approximately parallel to the lengthwise direction of side walls
506. If the blade portion 104 of implant 100 is angled as
illustrated in FIG. 6, then aperture 512 may extend from wall 508-1
at an angle relative to the plane defined by side wall 506-2 or
506-4 as will be understood by one skilled in the art. In some
embodiments, aperture 512 has a depth that is greater than or equal
to a length of blade portion 104 such that blade portion 104 may be
received within body 504 and engagement portion 106 abuts end wall
508-1. Similarly, end wall 508-2 defines an aperture 514 that is
sized and configured to receive an end of elongate driving rod 516
therein.
[0060] As best seen in FIGS. 23-25, driving rod 516 includes a fin
518 disposed at a first end 520. Fin 518 disposed at end 20 of
driving rod 516 has a rectangular shape and is sized and configured
to be received within aperture 512 of adapter 502. Fin 518 defines
a slot 522, which is sized and configured to receive a pin (not
shown) for cross-pinning driving rod 516 to adapter 502. In some
embodiments, end 520 may have other cross-sectional geometries
including, but not limited to, triangular, square, and pentagonal,
to name a few possibilities, that are configured to be received
within aperture 512. Adapter 502 may be over-molded onto the end of
driving rod 516. However, one skilled in the art will understand
that adapter 502 may be cross-pinned or otherwise coupled to
driving rod 516.
[0061] The opposite end 524 of driving rod 516 defines a pair of
flats 526, 528, which are disposed on opposite sides of driving rod
516. As best seen in FIG. 23, flat 526 extends from tip 530 and is
linearly spaced from flat 528, which is disposed at a greater
distance from tip 530 than flat 526. However, one skilled in the
art will understand that flats 526, 528 may be disposed at other
positions along driving rod 516. Flats 526, 528 are configured to
provide a contact surface for coupling to handle 532, which may be
over-molded onto driving rod 516, such that rotation of handle 532
is translated to driving rod 516.
[0062] Turning now to FIGS. 26 and 27, handle 532 has an elongate
body 534 that includes a plurality of ribs 536 that extend in a
longitudinal direction along body 534 to provide a gripping surface
for a user. As best seen in FIGS. 17 and 22, a smooth surface 538
interrupts circumferential ridges 540, which are disposed adjacent
to proximal end 542 also for providing a gripping surface for a
user.
[0063] Driver assembly 500 may be provided in a kit with a first
adapter 502 for use with a straight implant 100 and a second
adapter for use with an angled implant 100. A plurality of implants
100 of different sizes may also be provided in the kit. The kit may
be used in an operation similar to the operation described above
with respect to FIGS. 12A-16.
[0064] For example and referring to FIGS. 28A-33, an incision is
made to open the PIP joint 300 and a cutting tool 400 having a
blade 402 may be used to resect adjacent faces of proximal phalanx
302 and middle phalanx 304 as illustrated in FIGS. 28A and 28B. The
resected surfaces of proximal phalanx 302 and middle phalanx 304
may be debrided as understood by one skilled in the art.
[0065] Blade portion 104 of implant 100 is disposed within aperture
512 of adapter 502 as shown in FIGS. 29A and 29B. With blade
portion 104 disposed within aperture 512, an o-ring 544 (FIGS. 17
and 18) is placed in recess 510 defined by adapter 502 and within a
valley 126 of serrated edges 112 along the top and bottom sides
114, 116 of blade portion 104. O-ring 544 secures implant 100 to
adapter 502 such that implant does not move axially out of aperture
512.
[0066] Once implant 100 is secured to adapter 502, the surgeon uses
handle 534 to manually drive threaded portion 102 of implant 100
into the resected surface of proximal phalanx 302 as illustrated in
FIG. 30. Implant 100 is driven into proximal phalanx 302 until
engagement portion 106 abuts proximal phalanx 302. Implant 100 is
decoupled from adapter 502 by axially pulling handle 534 away from
implant 100 with sufficient force to flex o-ring 544 and separate
adapter 502 from implant 100.
[0067] Middle phalanx 304 may be predrilled or broached using drill
410 to create a hole 308 as shown in FIGS. 31 and 32. The
predrilled or broached middle phalanx 304 is then repositioned such
that the predrilled hole or broach 308 aligns with the blade
portion 104 of implant 100. The middle phalanx 304 is then pressed
into engagement with the blade portion 104 as shown in FIG. 33.
Serrated edges 112 of blade portion 104 help to maintain the
engagement between middle phalanx 304 and blade portion 104 of
implant 100.
[0068] The implant described above may advantageously be installed
through a small incision as described above. Additionally, the
improved implant is completely disposed within a toe of a patient,
which prevents the implant from being caught on bed sheets or other
objects like the conventional pins.
[0069] Although the invention has been described in terms of
exemplary embodiments, it is not limited thereto. Rather, the
appended claims should be construed broadly, to include other
variants and embodiments of the invention, which may be made by
those skilled in the art without departing from the scope and range
of equivalents of the invention.
* * * * *