Note: Descriptions are shown in the official language in which they were submitted.
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INTERSPINOUS PROCESS SPACER INSTRUMENT SYSTEM WITH
DEPLOYMENT INDICATOR
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and is a continuation-in-part of
U.S.
Provisional Patent Application Serial No. 61/069,083 entitled "Spacer
instrumentation
system with deployment indicator" filed on March 12, 2008 which is
incorporated
herein by reference in its entirety. This application also claims priority to
and is a
contintuation-in-part of U.S. Patent Application Serial No. 12/354,517
entitled
"Interspinous spacer" filed on January 15, 2009 which is a non-provisional of
U.S.
Provisional Patent Application No. 61/011,199 entitled "Interspinous spacer"
filed on
January 15, 2008 both of which are incorporated by reference herein in their
entireties. This application also claims priority to and is a continuation-in-
part of U.S.
Patent Application Serial No. 12/338,793 entitled "Spacer insertion
instrument" filed
on December 18, 2008 which is a non-provisional of U.S. Provisional Patent
Application Serial No. 61/008,418 entitled "Spacer insertion instrument" filed
on
December 19, 2007 both of which are incorporated herein by reference in their
entireties. This application also claims priority to and is a continuation-in-
part of U.S.
Patent Application Serial No. 12/205,511 entitled "Interspinous spacer" filed
on
September 5, 2008 which is a non-provisional of U.S. Provisional Patent
Application
Serial No. 60/967,805 entitled "Interspinous spacer" filed on September 7,
2007 and a
continuation-in-part of U.S. Patent Application Serial No. 12/220,427 entitled
"Interspinous spacer" filed on July 24, 2008 which is a non-provisional of
U.S.
Provisional Patent Application Serial No. 60/961,741 entitled "Insterspinous
spacer"
filed on July 24, 2007 and is a continuation-in-part of U.S. Patent
Application Serial
No. 12/217,662 entitled "Interspinous spacer" filed on July 8, 2008 which is a
non-
provisional of U.S. Provisional Patent Application No. 60/958,876 entitled
"Interspinous spacer" filed on July 9, 2007 and a continuation-in-part of U.S.
Patent
Application Serial No. 12/148,104 entitled "Interspinous spacer" filed on
April 16,
2008 which is a non-provisional of U.S. Provisional Patent Application Serial
No.
60/923,971 entitled "Interspinous spacer" filed on April 17, 2007 and U.S.
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Provisional Patent Application Serial No. 60/923,841 entitled "Spacer
insertion
instrument" filed on April 16, 2007, all of which are hereby incorporated by
reference
in their entireties. This application is also a continuation-in-part of U.S.
Patent
Application Serial No. 11/593,995 entitled "Systems and methods for posterior
dynamic stabilization of the spine" filed on November 7, 2006 and a
continuation-in-
part of U.S. Patent Application Serial No. 11/582,874 entitled "Minimally
invasive
tooling for delivery of interspinous spacer" filed on October 18, 2006 and a
continuation-in-part of U.S. Patent Application Serial No. 11/314,712 entitled
"Systems and methods for posterior dynamic stabilization of the spine" filed
on
December 20, 2005 and a continuation-in-part of U.S. Patent Application Serial
No.
11/190,496 entitled "Systems and methods for posterior dynamic stabilization
of the
spine" filed on July 26, 2005 and a continuation-in-part of U.S. Patent
Application
Serial No. 11/079,006 entitled "Systems and methods for posterior dynamic
stabilization of the spine" filed on March 10, 2005 and a continuation-in-part
of U.S.
Patent Application Serial No. 11/052,002 entitled "Systems and methods for
posterior
dynamic stabilization of the spine" filed on February 4, 2005 and a
continuation-in-
part of U.S. Patent Application Serial No. 11/006,502 entitled "Systems and
methods
for posterior dynamic stabilization of the spine" filed on December 6, 2004
and is a
continuation-in-part of U.S. Patent Application Serial No. 10/970,843 entitled
"Systems and methods for posterior dynamic stabilization of the spine" filed
on
October 20, 2004 and a continuation-in-part of U.S. Patent Application Serial
No.
11/006,521 entitled "Systems and methods for stabilizing the motion or
adjusting the
position of the spine" filed on December 6, 2004, and is a continuation-in-
part of U.S.
Patent Application Serial No. 11/305,820 entitled "Systems and methods for
posterior
dynamic stabilization of the spine" filed on December 15, 2005, all of which
are
hereby incorporated by reference in their entireties.
BACKGROUND
[0002] With spinal stenosis, the spinal canal narrows and pinches the spinal
cord and
nerves, causing pain in the back and legs. Typically, with age, a person's
ligaments
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may thicken, intervertebral discs may deteriorate and facet joints may break
down-
all contributing to the condition of the spine characterized by a narrowing of
the
spinal canal. Injury, heredity, arthritis, changes in blood flow and other
causes may
also contribute to spinal stenosis.
[0003] Doctors have been at the forefront with various treatments of the spine
including medications, surgical techniques and implantable devices that
alleviate and
substantially reduce debilitating pain associated with the back. In one
surgical
technique, a spacer is implanted between adjacent spinous processes of a
patient's
spine. The implanted spacer opens the spinal canal, neural foramen, maintains
the
desired distance between vertebral body segments, and as a result, reduces the
impingement of nerves and relieves pain. For suitable candidates, an
implantable
interspinous spacer may provide significant benefits in terms of pain relief.
[0004] Any surgery is an ordeal. However, the type of device and how it is
implanted has an impact. For example, one consideration when performing
surgery to
implant an interspinous spacer is the size of the incision that is required to
allow
introduction of the device. Small incisions and minimally invasive techniques
are
generally preferred as they affect less tissue and result in speedier recovery
times. As
such, there is a need for interspinous spacers and instruments that are used
to implant
them that work well with surgical techniques that are percutaneous and/or
minimally
invasive for the patient that can also be used in an open or mini-open
procedure. The
present invention sets forth such an instrument system.
SUMMARY
[0005] According to one aspect of the invention, an instrument system is
provided.
The system includes an interspinous process spacer, an inserter, a driver and
a
deployment indicator. The inserter is configured to releasably attach to the
spacer at
one end for implanting the spacer into a patient's interspinous process space.
The
driver that is connected to the inserter is configured to arrange the spacer
from at least
one undeployed configuration to at least one deployed configuration and the
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deployment indicator provides at least one information to the user pertaining
to the
degree of deployment of the attached spacer.
[0006] According to another aspect of the invention, an instrument for
inserting a
deployable interspinous process spacer into a patient is provided. The
instrument
includes a first end connectable to an interspinous process spacer and a
second end
configured to arrange a connected spacer between at least a first
configuration and at
least a second configuration. The instrument includes a sensor configured to
measrue
the arrangement of a connected spacer and provide a signal regarding the
arrangement
of a connected spacer to the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. IA illustrates a side view of a spacer instrument system connected
to a
spacer in a closed or an undeployed configuration according to the present
invention.
[0008] FIG. lB illustrates a side view of a spacer instrument system connected
to a
spacer in an open or deployed configuration according to the present
invention.
[0009] FIG. 2 illustrates a perspective partial end view of an inserter and
driver of a
spacer instrument system according to the present invention.
[0010] FIG. 3A illustrates a perspective view of a driver according to the
present
invention.
[0011] FIG. 3B illustrates a side view of a driver according to the present
invention.
[0012] FIG. 3C illustrates a cross-sectional view taken along line A-A of FIG.
3B of
the driver according to the present invention.
[0013] FIG. 3D illustrates a side view of a driver according to the present
invention.
[0014] FIG. 4A illustrates a perspective view of a spacer in an undeployed or
closed
configuration according to the present invention.
[0015] FIG. 4B illustrates a perspective view of a spacer in a deployed or
open
configuration according to the present invention.
[0016] FIG. 4C illustrates a top view of a spacer in a deployed or open
configuration
according to the present invention.
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DETAILED DESCRIPTION
[0017] Referring first to FIGs. 1A and 1B, there is shown a spacer instrument
system
with a deployment indicator according to the present invention connected to an
interspinous process spacer 12 in a closed or undeployed configuration and in
an open
or deployed configuration, respectively. The spacer instrument system 10
includes an
inserter 14 and a driver 16.
[0018] Still referencing FIGs. IA and lB and with additional reference to FIG.
2, the
inserter 14 will now be described. The inserter 14 is of the type described in
co-
pending U.S. Patent Application Serial No. 12/338,793 entitled "Spacer
insertion
instrument" filed on December 18, 2008 which claims the benefit of U.S.
Provisional
Patent Application Serial No. 61/008,418 entitled "Spacer insertion
instrument" filed
on December 19, 2007 both of which are assigned to VertiFlex, Inc. and hereby
incorporated by reference in their entireties. The inserter 14 is configured
to
releasably clamp to a body of an interspinous process implant or spacer 12 to
be
delivered into or removed from a patient using the system 10. The inserter 14
includes an inner shaft 18, an outer shaft 20, a control 22 and handle
assembly 24.
The inner shaft 18 is connected to the handle assembly 24 of the inserter 14
and the
outer shaft 20 is passed over the inner shaft 18 and allowed to translate with
respect to
the inner shaft 18 by means of a control 22 that is threadingly engaged with
the outer
shaft 20. With rotation of the control 22 in one direction, the outer shaft 20
translates
distally with respect to the stationary inner shaft 18. With rotation of the
control 22 in
the opposite direction, the outer shaft 20 translates proximally with respect
to the
stationary inner shaft 18. In another variation of the invention, the outer
shaft 20 is
connected to handle assembly 24 and the inner shaft is threadingly connected
to the
control 22 such that rotation of the control 22 moves the inner shaft 18 with
respect to
the outer shaft 20 proximally or distally. Although rotation of the control 22
is used
in one variation, other variations are within the scope of the present
invention such as,
for example, translation of the control 22 or movement of the outer shaft 20
relative to
the inner shaft 18.
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[0019] With particular reference to FIG. 2, the inner shaft 18 of the inserter
14 is
substantially cylindrical in shape having a central bore extending from end to
end.
The distal end of the inner shaft 18 includes a pair of prongs 26 with each
prong being
substantially oppositely located from each other. The finger-like prongs 26
are
flexible and, when in a normal position, splay slightly outwardly from the
longitudinal axis. The prongs 26 are configured to connect with the spacer 12.
In
particular, the prongs 26 include extensions 28 that extend inwardly toward
the
longitudinal axis in a hook-like fashion. These extensions 28 are configured
to be
inserted into prong-receiving portions 30 (see FIGs. 4A, 4B and 4C) on the
spacer 12
and securely clamp thereto. The prongs 26 also include conforming surfaces
configured to conform to the spacer 12 in a manner best suited for secure
attachment
thereto. The proximal end of the inner shaft 18 is configured for insertion
into and
connection with a conformingly shaped recess in the handle 24.
[0020] The outer shaft 20 of the inserter 14 will now be described. As seen in
FIG. 2,
the outer shaft 22 is substantially cylindrical in shape having a central bore
32
extending from end to end. The outer shaft 20 is sized such that the inner
shaft 18 fits
inside the outer shaft 20. The distal end includes a pair of flattened
portions 34
located substantially opposite from each other for a narrower profile and in
one
variation a ramped profile for insertion or placement between adjacent spinous
processes of a patient's spine. The ramped profile serves to distract the
adjacent
spinous processes apart slightly as the inserter is being inserted between the
adjacent
spinous processes for insertion of the connected spacer 12 wherein the
flattened
portions 34 are separated by an increasingly wider distance towards the
proximal end
of the instrument. The outer shaft 20 includes a threaded proximal portion
(not
shown). The threaded proximal portion is configured for threaded connection
with
the control 22 such that movement of the control 22 moves the outer shaft 20.
[0021] The control 22 includes a user interface such as a finger portion or
grip. In
one variation, the user interface is an outer circular or disk-shaped portion
for easily
effecting rotation of the control 22 with a thumb or index finger. The control
22 is
configured to effect relative translation of the inner shaft 18 with respect
to the outer
shaft 20.
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[0022] The spacer instrument system 10 functions to engage with, insert and
deploy
an interspinous spacer 12 in an interspinous process space between two
adjacent
vertebrae. Illustrative examples of interspinous spacers that are compatible
with the
insertion instrument are described in applicant's co-pending U.S. Patent
Application
Serial No. 12/148,104 entitled "Interspinous spacer" filed on April 16, 2008
which
claims the benefit of U.S. Provisional Patent Application Serial No.
60/923,841
entitled "Spacer insertion instrument" filed on April 16, 2007 and U.S.
Provisional
Patent Application Serial No. 60/923,971 entitled "Interspinous spacer" filed
on April
17, 2007, U.S. Patent Application Serial No. 12/217,662 entitled "Interspinous
spacer" filed on July 8, 2008 which claims the benefit of U.S. Provisional
Patent
Application Serial No. 60/958,876 entitled "Interspinous spacer" filed on July
9,
2007, U.S. Patent Application Serial No. 12/220,427 entitled "Interspinous
spacer"
filed on July 24, 2008 which claims the benefit of U.S. Provisional Patent
Application
Serial No. 60/961,741 entitled "Interspinous spacer" filed on July 24, 2007,
and U.S.
Patent Application Serial No. 12/205,511 entitled "Interspinous spacer" filed
on
September 5, 2008 which claims the benefit of U.S. Provisional Patent
Application
Serial No. 60/967,805 entitled "Interspinous spacer" filed on September 7,
2007, and
U.S. Patent Application Serial No. 12/354,517 entitled "Interspinous spacer"
filed on
January 15, 2009 which claims the benefit of U.S. Provisional Patent
Application
Serial No. 61/011,199 entitled "Interspinous spacer" filed on January 15, 2008
the
disclosure of all of which are incorporated herein by reference in their
entireties. An
example of an interspinous spacer 12 is shown in FIGs. 4A, 4B and 4C. In
general,
each spacer 12 includes a body portion 36 with at least one prong receiving
portion 30
for connecting with the instrument 10, at least one wing 40 rotatably
connected to the
body 36 and an actuator shaft 38 housed in the body portion 36 and configured
to
arrange the at least one wing 40 from at least one undeployed configuration
(see FIG.
4A) to at least one deployed configuration (see FIGs. 4B and 4C) and vice
versa. The
wings 40 are configured to laterally stabilize the body portion 36 relative to
thespinous processes, seat and/or space apart the spinous processes of
adjacent
vertebrae when in the deployed configuration to relieve pain.
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[0023] The spacer instrument system 10 utilizes the working channel that is
preferably created by the use of one or more tools such as a target needle, K-
wire,
dilators, mounting bracket, cannula, stabilizing arm, interspinous knife,
interspinous
reamer, and interspinous gage, all described in applicant's co-pending U.S.
Patent
Application Serial No. 11/582,874 entitled "Minimally invasive tooling for
delivery
of interspinous spacer" filed on October 18, 2006, incorporated herein by
reference in
its entirety. The inserter 14 is typically inserted through a cannula with the
distal end
positioned at the interspinous process space in a minimally invasive,
percutaneous,
mini-open or open surgical procedure. In some procedures, a cannula is not
employed to deliver the spacer instrument system 10 and spacer 12 to the
interspinous
space.
[0024] In use, a spacer 12 is placed in juxtaposition to the distal end of the
inserter 14
such that the prongs 26 of the inserter 14 are adjacent to the prong receiving
portions
30 on the spacer 12. The control 22 is then activated to clamp the prongs 26
of the
inner shaft 18 onto the spacer 12. In particular, the control 22 is rotated in
one
direction which advances the outer shaft 20 over the inner shaft 18 to thereby
inwardly deflect the outwardly splayed prongs 26 at the distal end of the
inner shaft
18. This inward deflection allows the prongs 26 to engage the spacer body 36
and, in
particular, allows the prong extensions 28 to be inserted into the prong
receiving
portions 30 and with further rotation of the control 22 to lock the inserter
14 securely
onto the spacer 12. Reverse rotation of the control 22 translates the outer
shaft 20
proximally to expose the prongs 26 allowing them to splay outwardly to their
pre-
stressed normal position and thereby release the spacer 12 from the inserter
14.
[0025] If a cannula is employed in the operative site, the inserter 14 with
the attached
spacer 12 is sized to fit through a cannula and is passed through the cannula
to the
interspinous process space. Once in position inside the patient, the driver 16
is
inserted into the proximal opening of the central passageway of the inserter
14 and
passed until the driver 16 connects with the spacer 12.
[0026] Turning now to FIGs. 3A, 3B, 3C and 3D, the driver 16 will now be
described. The driver 16 includes: (1) a handle 42 having a proximal end 44
and a
distal end 46, (2) a inner shaft 48, (3) outer shaft 50, (3) a spacer engaging
bit 54
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connected to the distal end of the outer shaft 50, and (4) a spring 52. The
outer shaft
50 which is connected to the distal end 46 of the handle 42 includes a lumen
in which
the inner shaft 48 is disposed. The inner shaft 48 includes a collar 56 (shown
in FIG.
3C) configured to be located inside the handle 42 and biased against the
spring 52 and
configured such that the spring 52 forces the inner shaft 48 distally in a
direction
towards the spacer engaging bit 54. The proximal end 44 of the handle 42
includes a
deployment indicator window 58 through which the inner shaft 48 is viewed.
FIG. 2
illustrates the distal end of the driver 16 inserted into the inserter 14.
[0027] Depending on the spacer 12 design, the connection of the driver 16 with
the
spacer 12, in particular the spacer engaging bit 54, will be different. In
general,
however, the driver 16 connects to the spacer 12 such that movement, such as
rotation, of the driver 16 effects deployment of a deployable spacer 12, in
particular,
the deployment of the at least one wing 40 of the spacer 12. In particular,
and with
respect to the spacer embodiment shown in FIGs. 4A-4C, rotation of the driver
16 that
is connected to the spacer 12 effects translation of the actuator shaft 38 of
the spacer
12 which in turn is connected to the at least one wing 40 causing it to deploy
into an
expanded configuration or deployed configuration.
[0028] The driver 16 that is configured to connect with the spacer 12 of FIGs.
4A-4C
will have a spacer engaging bit 54 that includes two projecting features 60.
The two
projecting features 60 engage complementary features 62 on the spacer 12
located
inside the spacer body portion 36 as shown in FIGs. 4A-4C. Once engaged to the
spacer 12, rotation of the driver 16 rotates the spindle 64 which in turn
advances the
actuator shaft 38 to deploy the wings 70 into the configuration shown in FIGs.
4B and
4C. Reverse rotation of the driver 16 will turn the spindle 64 in an opposite
direction
and proximally translate the actuator shaft 38 to undeploy the wings 40. As
can be
seen in FIGs. 4B and 4C, when in the deployed configuration, the actuator
shaft 38 is
distally translated with rotation of the driver 16 relative to when in the
undeployed
configuration as shown in FIG. 4A wherein the actuator shaft 38 projects
proximally
from the spacer body 36. This distance traveled by the actuator shaft 38
provides the
information about the degree of deployment of the wings 40 of the spacer 12
that is
communicated to the inner shaft 48 of the driver 16. With the inserter 14
connected
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to the spacer 12 and the driver 16 inserted into the central passageway of the
inserter
14 and connected to the spindle 64 such that the projecting features 60 of the
bit 54
engage the features 62 on the spindle 64, the inner shaft 48 of the driver 16
contacts
the proximal end 66 of the actuator shaft 38 and will bias the inner shaft 48
a distance
related to the distance with which the actuator shaft 38 projects proximally
from the
spacer body 36. Hence, as the driver 16 is rotated to effect translation of
the actuator
shaft 38 inwardly or outwardly to deploy or undeploy the spacer, the bias
force of the
spring 52 will keep the distal end of the inner shaft 48 of the driver 16 in
contact with
the proximal end 66 of the actuator shaft 38 as it translates proximally or
distally
providing an indication as to the degree of deployment of the spacer 12. The
indication as to the degree of deployment of the spacer 12 is viewed at the
proximal
end of the system 10. Because the handle 24 resides outside the patient, the
deployment information is readily visible to the surgeon.
[0029] Referring back to FIG. IA, there is shown the system 10 in an
undeployed
configuration. As can be seen, at the proximal end, the inner shaft 48
projects
outwardly from the proximal end 44 of the handle 24. As the driver 16 is
rotated to
deploy the spacer 12, the inner shaft 48 moves distally until the inner shaft
48 does
not project outwardly from the proximal end 44 of the handle 24 and/or is co-
planar
with the proximal end 44 of the handle 24 as shown in FIG. 1B, thereby
providing the
user with a visual indication of the degree of deployment of the spacer 12
wherein if
the inner shaft 48 is not projecting then the spacer 12 is fully deployed and
if the inner
shaft 48 is projecting from the proximal end 44 of the handle 24 then a state
other
than full deployment is indicated. The degree of deployment is related to the
distance
with which the inner shaft 48 is projecting outwardly from the proximal end 44
of the
handle 24. The proximal end of the inner shaft 48 or "button" provides the
surgeon
not only with visual feedback but also tactile feedback as to the degree of
deployment.
[0030] Another deployment indicator is provided alternatively or in
conjunction with
the projection of the inner shaft 48 from the proximal end 44 just described.
This
other deployment indicator includes an indicator line 68 (shown in FIGs. lB
and 3D)
provided on the inner shaft 48 of the driver 16, which becomes visible through
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indicator window 58 as the inner shaft 48 translates with deployment of the
spacer 12.
When in the undeployed configuration as shown in FIG. IA, the indicator line
68 is
proximal of the window 58 and therefore not visible through the indicator
window 58.
When the spacer 12 approaches a deployed configuration, the indicator line 68
will
enter the indicator window 58 and be visible to the user. An additional
alignment line
or lines 70 is provided on the proximal end 44 of the handle 24 adjacent to
the
indicator window 58 as shown in FIGs. lB and 3D. When the indicator line 68 on
the
inner shaft 48 is aligned with the alignment line or lines 70 on the handle
24, a fully
deployed configuration of the spacer 12 is indicated providing a visual
information of
deployment to the surgeon.
[00311 The above description is one variation of mechanical sensor connected
to the
instrument for measuring the arrangement of a connected spacer 10. One skilled
in
the art will recognize that the instrument can be configured with any suitable
sensor
that can be effectively employed to measure the arrangement of the spacer and
provide a signal to the user regarding the arrangement of the connected
spacer.
Examples of suitable sensors include, but are not limited to mechanical,
position,
optical, electromagnetic, motion, and distance sensors. Of course, suitable
signals
communicating the measured information include audible, visual, tactile
signals and
the like. The signal may be transmitted to a receiver located on the
instrument itself
preferable at a location that is resident outside the patient while in use or
at a location
remote of the instrument. In one variation, the sensor provides a signal only
upon full
deployment of the spacer. In another variation, the sensor provides continuous
information as to the arrangment of the spacer.
[0032] Hence, the present invention advantageously provides information
regarding
the degree of deployment of the spacer to the surgeon which is particularly
advantageous in minimally invasive and percutaneous procedures where the
device
cannot be viewed without the aid of fluoroscopy because of visual obstruction
accompanying very small incisions. As a result of the deployment information
provided by the system, this invention advantageously reduces time required to
implant the spacer and also advantageously reduces the number of fluoroscopy
shots
that the clinicians and patients are exposed to during the procedure as the
deployment
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information is readily provided to the surgeon by the spacer instrument system
with
deployment indicator that is located outside patient incision.
[0033] All publications mentioned herein are incorporated herein by reference
to
disclose and describe the methods and/or materials in connection with which
the
publications are cited. The preceding illustrates the principles of the
invention. It
will be appreciated that those skilled in the art will be able to devise
various
arrangements which, although not explicitly described or shown herein, embody
the
principles of the invention and are included within its spirit and scope.
12
