Title of Invention

ELECTRICALLY INSULATED SURGICAL NEEDLE ASSEMBLY

Abstract A surgical needle assembly (30) for penetrating soft and hard tissues of a patient includes a handle assembly (80) removably coupled to the needle assembly (30). The needle assembly (30) is electrically coupled to an electrical signal source. The surgical tool (20) includes an electrically conductive portion in communication with an un-insulated distal end of the needle assembly (30), and an insulated portion extending from the distal end to the handle assembly (80).
Full Text P22353.01
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ELECTRICALLY INSULATED SURGICAL NEEDLE ASSEMBLY
BACKGROUND
Monitoring of the location of neural elements can reduce the likelihood of
neural damage while accessing anatomical structures near the nerve. Systems exist
which provide for delivery of an electrical current for detection of neural element
proximity to a carrier of the current by visibly noting a patient's limb motor reaction
when the neural element is stimulated by electrical current.
Surgical needle assemblies can be employed for access, treatment and/or
delivery of treatment to locations within a patient's body. The needle assembly is
inserted for penetration of soft and hard tissues of the patient during the initial steps of
the treatment protocol without determining the proximity of neural elements to the
needle assembly during and after such placement of the needle assembly. Subsequent
treatments and procedures that are carried out based on the initial needle insertion
position may impinge or interfere with the neural elements, requiring relocation of the
treatment location or pathway.
SUMMARY
The present system includes a surgical tool useable by a surgeon to penetrate
soft and hard tissue of the patient with a needle assembly. The needle assembly can
be electrically coupled to a nerve monitoring system to allow the monitoring and
detection of neural elements as the needle assembly is advanced into the patient
through skin and tissue. The distal tip of the needle assembly carries the electrical
signal, and the outer surface of the needle assembly is insulated to prevent shunting of
the signal to tissue or instruments proximal of the distal tip. Corrective action to
avoid impingement or to provide sufficient spacing from neural elements can taken
during needle assembly placement, reducing the likelihood that corrective actions will
need to be taken later in the surgical procedure to avoid or provide sufficient
clearance with neural elements.
In one form, the needle assembly is removably engageable to a handle
assembly that facilitates manipulation and control of the needle assembly as it is

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advanced into the patient. In|one embodiment, the handle assembly is configured to
allow gripping thereof by the hand of the surgeon while maintaining the electrical
lead coupling the needle assembly to the nerve monitoring system out of the way of
the surgeon.
In one procedure, the surgical tool is used in minimally invasive spinal
surgical procedures. The needle assembly is percutaneously advanced into the patient
and engaged to the pedicle of a vertebra. During such engagement, the proximity of
neural elements to the distal tip is monitored to allow for corrective action to be taken
to avoid or provide sufficient spacing of the needle assembly from neural elements
during this initial access phase of the procedure. In one embodiment, when the needle
is engaged to the pedicle at the desired location, the handle assembly is removed from
the needle assembly. The needle assembly includes a cannula housing a stylet, and
the stylet is removed so that the cannula remains engaged to the pedicle. A guidewire
can be positioned through the lumen of the cannula, and the cannula withdrawn. The
guidewire can then guide other instruments, implants or other surgical devices or
instruments to the pedicle. Other procedures are contemplated at locations along the
spinal column other than the pedicles, and at other locations within the body of the
patient other than the spinal column.
BRIEF DESCRIPTION OF THE FIGURES
Fig. 1 is a view of the surgical field with an assembled perspective view of a
surgical tool and nerve and monitoring system.
Fig. 2 is an elevation view in partial section of the surgical tool including a
needle assembly coupled to a handle assembly.
Fig. 3 A is a section view along line 3A-3A of Fig. 2.
Fig. 3B is a distal end view of the handle assembly of Fig. 2.
Fig. 4 is an elevation view of a stylet comprising a portion of the needle
assembly of Fig.
Fig. 5A is an elevation view of a cannula comprising a portion of the needle
assembly of Fig.
FIG. 5B is a section view along line 5B-5B of Fig. 5A.

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FIG. 6 is an elevation view of a lead comprising a portion of the surgical tool
of Fig. 1.
FIG. 7 is an elevation view of a housing comprising a portion of the handle
assembly.
FIG. 8 is a section view through line 8-8 of Fig. 7.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
While this device is susceptible of embodiment in many different forms, there
is shown in the drawings, and will herein be described in detail, several specific
embodiments, with the understanding that the present disclosure can be considered as
an exemplification and is not intended to be limited to the embodiments illustrated.
The present system relates to surgical tools used in accessing locations within
the body of the patient while monitoring the proximity of neural elements to the tool.
In one form, the surgical tool includes a needle assembly electrically engageable to a
nerve monitoring system, where the needle assembly is operable to carry an electrical
signal at its distal tip and allow the surgeon to monitor the proximity of neural
elements with the nerve monitoring system as the needle is advanced to the target
location in the patient. The proximity of the needle assembly to the neural elements
can be controlled to reduce the potential neural element impact of needle insertion and
subsequent procedures carried out based on the needle insertion location. The target
location may include bony structures, an organ, a canal or space, a tumor or other
defect, or any anatomical location or structure within a patient. The needle assembly
includes a structure that facilitates operative positioning and control by the surgeon
during the procedure. Once the needle has been positioned at the target location,
subsequent procedures can be carried out. Such subsequent procedures can include
therapy, implants, substances, or the like provided by, through or upon the needle
assembly. Subsequent procedures may also include using the needle assembly as a
platform or guide for subsequent placement of instruments, implants and other
devices and therapeutic materials.
The needle assembly includes a distal needle structure positionable within the
patient and operable to carry an electrical signal, a handle assembly, and an electrical

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lead. In one embodiment, the needle structure is removably engageable to the handle
assembly, although embodiments where the needle assembly is integral with the
handle assembly are also contemplated. The needle assembly is operable to deliver an
electrical signal, such as a current, to a location in the patient's body to monitor
proximity of the neural elements to the inserted end of the needle structure. The lead
can extend from the handle assembly to an electrical signal source. Another lead can
be used to ground the circuit. The needle assembly, when assembled with the handle
assembly, can be completely insulated, except for the distal insertion end, to prevent
shunting of the electrical signal to tissue or instruments located proximally of the
insertion end.
Referring to Figs. 1 and 2, there is provided view of a surgical field 24 that
includes a portion of the posterior spinal column shown in hidden lines beneath the
skin and tissue of a patient and surgical tool 20. Surgical field 24 includes spinal
column segment 25 having a number of vertebrae therealong, it being understood that
surgical tool 20 can have application in any region of the spine and in any approach to
the spine. It is also understood that surgical tool 20 has application in procedures
other than spinal surgical procedures.
Surgical tool 20 includes a needle assembly 30 and a handle assembly 80.
Needle assembly 30 is received in a receptacle 86 extending axially into handle
assembly 80. Needle assembly 30 can be electrically coupled to a nerve monitoring
system 22 via lead 100 when positioned in receptacle 86. Lead 100 extends into
handle assembly 80 via a lateral bore 88, where it is electrically coupled to needle
assembly 30. A second reference 27 coupled to a patient (not shown) can be provided
as a ground. In one procedure, the needle assembly 30 is positionable through the
skin and soft and hard tissues of the patient to a surgically appropriate target location
such as, for example, the pedicle of a vertebra of spinal column segment 25.
Subsequent procedures and instruments for accessing the spinal column can then be
employed using the needle assembly and target location obtained thereby as a
minimally invasive platform for treatment and/or placement of devices and implants
to treat conditions associated with the spinal column.

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Needle assembly 30 includes a cannula 40 and stylet 60 removably received in
a central lumen of cannula 40 along a longitudinal axis 38. Stylet 60 may include any
suitable distal tip configuration, such as a trocar tip configuration as shown or a
beveled tip configuration. Other embodiments contemplate a needle assembly that
includes a single needle element. The needle element can be solid or cannulated. In
the illustrated embodiment, handle assembly 80 is removably positioned about the
proximal ends of cannula 40 and stylet 60 and engaged thereto to facilitate handling
and positioning of needle assembly 30 through skin and tissue to the target location in
the patient's body. An outer sheath 32 may also be provided for positioning about
cannula 40 and/or stylet 60. Sheath 32 may be provided with a length extending to a
distal end thereof (not shown) that extends distally beyond the distal ends of cannula
40 and/or stylet 60. Sheath 32 can facilitate pre-operative handling of needle
assembly 30 to prevent, for example, accidental punctures, cutting and contamination
of needle assembly 30.
Stylet 60 is shown in isolation in Fig. 4. Stylet 60 includes a pointed tip 62
adjacent its distal end and an elongate shaft 64 extending proximally from tip 62. A
hub 66 is provided at the proximal end of shaft 64. Hub 66 includes an enlarged body
70 extending radially about shaft 64, and a proximal extension 68 extending
proximally from body 70.
Cannula 40 is shown in Figs. 5A and 5B. Cannula 40 includes a central lumen
41 extending therealong and opening at a distal end 42 and a proximal end 53. The
outer surface area of cannula 40 may be covered or coated with a non-conductive or
insulative material or member to prevent shunting of electricity from cannula 40 to
adjacent tissue or instruments. A distal cannula portion 44 extends proximally from
distal end 42 to a transition portion 48. Transition portion 48 extends to a proximal
cannula portion 46. Proximal cannula portion 46 may include a greater outside
diameter than distal cannula portion 44 to provide sufficient rigidity to cannula 40
while minimizing the size of the leading end of cannula 40. Distal end 42 may also be
beveled to facilitate penetration and passage of cannula 40 through skin and tissue to
the target location in the patient. Other embodiments contemplate a single diameter
cannula, or a cannula with more than two diameters.

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The proximal end of cannula 40 includes a connection member 50.
Connection member 50 may be comprised of a non-conductive material, or of a
conductive material having ah insulated coating. Connection member 50 includes a
proximal end fitting 52 configured to facilitate attachment of various devices to
cannula 40. In one embodiment, fitting 52 provides a luer-type connection. Other
embodiments contemplate other connection arrangements that are provided by fitting
52. Connection member 50 may further includes a distal sleeve portion 54 extending
about proximal cannula portion 46. Distal sleeve portion 54 overlaps the insulated
surface area of cannula portion 46 to ensure the cannula 40 is entirely insulated
adjacent its proximal end.
Connection member 50 also includes a gripping portion 56 with opposite,
laterally extending wings and concave surface depressions that allow the user to grip
cannula 40 to facilitate handling when handle assembly 80 is removed. Connection
member 50 also includes a proximal sleeve portion 57 extending proximally from
gripping portion 56. Notches 58 are provided in opposite sides of sleeve portion 57,
and as discussed further below, are engageable by a locking element to secure cannula
40 to handle assembly 80. Stylet 60 is positionable in cannula 40 so that distal tip 62
projects distally of distal end 42 when hub 66 is positioned against the proximal end
of connection member 50.
Referring to Fig. 6, there is shown lead 100 that extends from handle assembly
80 and is electrically engageable to stylet 60 when stylet 60 is engaged in handle
assembly 80. Link 100 includes a flexible cable portion 102 extending between a
connector 106 at one end and a contact 104 at the opposite end. Connector 106 and
cable portion 102 can include an outer surface layer that is plastic to facilitate
cleaning and protect the conductive wiring, leads and other electrical transmission
structures therein. Connector 106 can be configured for electrical engagement with a
lead from a nerve monitoring system or the like such as the NIM-Spineā„¢ System
marketed by Medtronic, Inc.or any other suitable nerve monitoring system.
Contact 104 is housed within handle assembly 80, and is electrically
engageable to proximal extension 68 of stylet 60 when hub 60 is positioned in handle
assembly 80. In the illustrated embodiment, housing 108 is positioned in the laterally

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oriented bore 88 of handle 80 to secure lead 100 to handle assembly 80. Housing 108
includes a body 110 and a longitudinal trough 112 extending therealong and opening
along a side of housing 108. Body 110 includes axial protrusions 114 and lateral
protrusions 116 projecting into trough 112 that engage cable 102 and maintain it in
position in trough 112. In particular, the opposing lateral protrusions provide restraint
of cable 102 within body 110, and the axial protrusions push and facilitate frictional
engagement of cable 102 against the inner surface defining bore 88. Body 110 can be
engaged in bore 88 via any one or combination of a friction fit, fasteners, adhesives or
welding or fusing of body 110 to handle 80.
With body 110 securely positioned in bore 88, contact 104 projects into a
proximal portion 94 of receptacle 86. The proximal extension 68 of hub 60 is
comprised of an electrically conductive material that contacts contact 104 in proximal
portion 94 and electrically couples stylet 60 and cannula 40 to the electrical signal
source.
Cannula 40 and stylet 60 may be made of stainless surgical steel or other
suitable conductive material of sufficient strength to penetrate tissue of the patient to
the target location. Cannula 40 and stylet 60 can be constructed from a single piece of
suitable conductive material or could be constructed from more than one piece of
suitable conductive material. Cannula 40 is provided with an insulated surface area
between its distal and proximal ends that can be achieved through the use of a coating,
e.g. polyamide coating or through other means, such as an overlaying sleeve of foam
or other material. The insulated surface area ensures the electrical signal is directed to
the target area adjacent the distal ends of stylet 60 and cannula 40 and is not shunted
to surrounding, unintended, tissue or surgical instruments.
Handle assembly 80 is shown in Figs. 2 and 3A-3B. Handle assembly 80
comprises a handle body 82 with an electrically insulated surface area 90 and an
electrically conductive area 95 internal to handle body 82. Access to electrically
conductive area 95 is provided via a distally opening receptacle 86 in a distally
extending neck portion 84 of handle body 82. Neck portion 84 includes a channel 96
that receives a locking element 76. A lateral bore 88 extends transversely to and
opens at a lateral surface 92 of handle body 82. Lead 100 is positioned in bore 88.

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Handle body 82 of handle assembly 80 includes a proximal gripping portion
formed to include a major dimension 83 and a minor dimension 85. The major and
minor dimensions 83, 85 are measured orthogonally to one another and orthogonally
to an extension of longitudinal axis 38 through handle body 82. In one embodiment,
the major dimension is at least 50% greater than the minor dimension. The provision
of handle body 82 with a gripping portion having such major and minor dimensions in
this manner accommodates the hand of the surgeon or other attendant, and facilitates
manipulation and control of needle assembly 30 with handle assembly 80. The
proximal end of body 82 includes continuously curved outer surfaces at its interface
with the user's hand. This enables a user to have a secure and comfortable grasp on
the handle assembly 80. Furthermore, bore 88 extends along the major dimension to
position lead 100 away from the gripping surfaces of body 82. Lead 100 exits one of
the lateral surfaces 92 to prevent lead 100 from interfering with gripping and control
of needle assembly 30.
In another embodiment, lead 100 is engageable with an outlet or receptacle
provided adjacent lateral surface 92. The outlet or receptacle is electrically coupled to
needle assembly 30 in handle assembly 80.
Channel 96 in neck portion 84 opens into axially extending receptacle 86
formed in handle body 82. Receptacle 86 can include a distal portion that has the
same cross-sectional size and shape as the proximal end hub 66 provided on stylet 60.
In addition, the proximal end connection member 50 of cannula 40 includes a
proximal sleeve portion 57 having the same size and shape as receptacle 86. The
form fitting engagement between receptacle 86 and fitting 50 and hub 66 prevents
rotation and provides a secure connection that eliminates movement between needle
assembly 30 and handle assembly 80. In the present embodiment, receptacle 86 has
an oblong shape that is asymmetric. As a result, receptacle 86 will receive the
proximal end portions of stylet 60 and cannula 40 when in proper alignment with the
shape of receptacle 86.
When assembled, proximal sleeve portion 57 of connection member 50 of
cannula 40 occupies receptacle 86 adjacent channel 96, and notches 58 of sleeve
portion 57 are aligned relative to channel 96. Cannula 40 is secured in receptacle 86

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by locking element 76 in channel 96. In one embodiment, stylet 60 is press fit into
receptacle 86 for engagement with handle assembly 80 so that proximal extension 68
of stylet 60 extends into a smaller proximal portion 94 of receptacle 86 and maintains
a constant electrical connection with contact 104 of lead 100, thereby electrically
coupling lead 100 to needle assembly 30.
In another embodiment, stylet 60 is removable from handle assembly 80 and
also removable from cannula 40. In this embodiment, the electrical connection
between lead 100 and stylet 60 can be maintained by any conventional means known
to a person skilled in the art, such as a spring made of a conductive material. Such a
spring could be mounted in bore 88 or receptacle 86, such that it makes contact with a
conductive area of stylet 60 or cannula 40 when attached to handle assembly 80. The
releasable connection also does not interfere with removal of handle assembly 80
from needle assembly 30 when it is desired to withdraw stylet 60 from cannula 40.
In the illustrated embodiment, channel 96 comprises a shallow channel
extending circumferentially about neck portion 84, and extends approximately three-
quarters of the way around neck portion 84. Channel 96 includes through-holes 97,
99, which are located opposite from one another and open into side portions of
receptacle 86. Channel 96 begins at first through-hole 97, and extends
counterclockwise approximately one-quarter revolution past second through-hole 99
where it terminates.
Locking element 76 can be in the form of a substantially flat, semicircular
member having an aperture diameter slightly larger than the inner diameter of channel
96. Locking element 76 an outer gripping surface 78, which facilitates rotation of
locking element 76 by the user. Locking element 76 is adapted to fit within channel
96 and has an outer circumference extending slightly less than three-quarters around
neck portion 84.
Locking element 76 can be manipulated and rotated within channel 96 about a
small angular displacement on the order of one-eighth of one rotation. This
effectively allows for locking element 76 to be toggled between two positions, which
correspond to the locked and unlocked configurations relative to handle assembly 80.
When locking element 76 is rotated counterclockwise, no portions of locking element

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76 protrude through through-holes 97 and 99, as shown in Fig. 3A, and locking
element 76 does not obstruct receptacle 86. In this configuration, a groove 72 of
locking element 76 is aligned with second through-hole 99, and on the other side of
channel 96, the end 74 of locking element 76 is located slightly counterclockwise of
second through-hole 97. This position corresponds to the unlocked orientation which
allows removal and insertion of cannula 40 and hub 60 relative to handle assembly
80. Alternatively, when locking element 76 is rotated clockwise as far as possible,
groove 72 is no longer aligned with through-hole 99, thereby causing a portion of
locking element 76 to protrude through through-hole 99 and obstruct one side portion
of passage 86. Additionally, the end 74 of locking element 76 now protrudes through
the other through-hole 97, obstructing the other side portion of passage 86. This
position of locking element 76 corresponds to the locked orientation which engages
cannula 40 in handle assembly 80.
In order to join handle assembly 80 to cannula 40, connection member 50 is
inserted through the distal opening of receptacle 86 of handle assembly 80 when
locking element 76 is in the unlocked orientation. If locking element 76 is in the
locked orientation, then side portions of receptacle 86 will be obstructed by locking
element 76 at through-holes 97, 99, thereby preventing full insertion of cannula 40
into handle assembly 80. When proximal sleeve portion 57 is fully inserted into
passage 86, enlarged gripping portion 56 will abut the distal end of neck portion 84 of
handle assembly 80, and notches 58 in sleeve portion 57 will be aligned with through-
holes 97, 99.
Proximal extension 68 of stylet 60 is electrically engaged with contact 104 of
lead 100 in handle assembly 80. Once the proximal portion of cannula 40 has been
fully inserted into receptacle 86, the user may then lock handle assembly 80 to needle
assembly 30 by rotating locking element 76 clockwise relative to its Fig. 3
orientation. As locking element 76 is rotated from its unlocked position to its locked
position, needle assembly 30 is fixed in place within receptacle 86. Portions of
locking element 76 protrude through through-holes 97, 99 into notches 58 to secure at
least cannula 40 of needle assembly 30 in position relative to handle assembly 80.
The user of needle assembly 30 can use a large amount of force, if necessary, to

P22353.01
manipulate and penetrate needle assembly 30 through tissue and/or bone, without
undesired movement of needle assembly 30 relative to handle assembly 80.
While the invention has been illustrated and described in detail in the drawings and
foregoing description, the same is to be considered as illustrative and not restrictive in
character, and that all changes and modifications that come within the spirit of the
invention are desired to be protected.

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What is claimed is:
1. A surgical tool for penetrating tissue and monitoring the proximity of
neural elements, comprising:
a needle assembly extending along a longitudinal axis, said needle assembly
comprising:
a stylet including an electrically conductive portion near a pointed
distal end, a shaft extending proximally from said distal end providing a
conductive path to a proximal extension of said stylet;
a cannula including an insulated outer surface area and a length
wherein said pointed distal end of said stylet projects distally from said
insulated surface area when said stylet is positioned in said cannula;
a handle assembly attachable near said proximal end of said needle assembly
comprising:
an electrically insulated outer surface area;
an electrically conductive area internal to said electrically insulated
surface area and engageable with said proximal extension of said stylet;
said handle assembly including a gripping portion having a major
dimension at least 50% greater than a minor dimension, said major and minor
dimensions being measured orthogonally to said longitudinal axis and to one
another; and
an electrical lead extending from said electrically conductive area through said
handle assembly along said major dimension.
2. The surgical tool of claim 1, wherein said cannula includes a distal end
positioned proximally of said distal pointed end of said stylet when said stylet is
positioned in said cannula.
3. The surgical tool of claim 2, wherein said cannula includes a
connection member on a proximal end there of and said stylet includes a hub about a
proximal end of said stylet positonable in abutting engagement with a proximal end of
said connection member of said cannula.

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4. The surgical tool of claim 3, wherein said hub includes a body
extending about said shaft and said proximal extension of said stylet extends
proximally from said body.
5. The surgical tool of claim 3, wherein said connection member on said
cannula includes a gripping portion projecting outwardly from said cannula, a first
sleeve portion extending about said cannula distally of said gripping portion, and a
second sleeve portion about said cannula proximally of said gripping portion.
6. The surgical tool of claim 5, wherein said second sleeve portion
includes a pair of notches for receiving a locking element to couple said needle
assembly to said handle assembly with said hub and said connection member are at
least partially received in said handle assembly.
7. The surgical tool of claim 1, wherein said proximal extension of said
stylet fits inside a receptacle within said handle assembly, said receptacle including an
electrical contact for engaging said proximal extension and electrically coupling said
needle assembly with said lead.

8. The surgical tool of claim 1, wherein said cannula includes a distal end
beveled to facilitate movement of said cannula through tissue of the patient.
9. The surgical tool of claim 1, wherein said cannula includes a lumen
having a generally constant size between distal and proximal ends of said cannula.
10. The surgical tool of claim 1, wherein said lead extends along said
major dimension of said handle assembly and exits said handle assembly at a location
distally of said curved surfaces to avoid interfering with the user's hand positioned
about said gripping portion.
11. The surgical tool of claim 1, wherein said handle assembly includes a
handle body having a bore extending along said major dimension from a lateral outer
surface of said handle body to a receptacle aligned along said longitudinal axis of said
needle assembly when said handle assembly is engaged thereto, said lead extending
through said bore.
12. The tool of claim 11, further comprising a body positionable in said
bore, said body defining trough for receiving a cable portion of said lead and securing
said cable portion in said handle assembly.

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13. A surgical tool for penetrating tissue and monitoring the proximity of
neural elements, comprising:
a needle assembly extending along a longitudinal axis, said needle assembly
comprising:
an exposed, electrically conductive portion near a distal end, said distal
end being adapted for penetrating tissue;
a proximal portion;
insulated surface area extending about a conductive path between said
conductive portion arid said proximal portion;
a handle assembly, comprising:
an electrically insulated surface area;
an electrically conductive area internal to said electrically insulated
surface area;
an opening for receiving said proximal portion of said needle assembly
in electrical engagement with said electrically conductive area;
a gripping portion extending along a major dimension and a minor
dimension, said minor dimension being less than said major dimension and
said major and minor dimensions being measured orthogonally to said
longitudinal axis and ito one another; and
an electrical lead extending along said major dimension from said
electrically conductive area internally of said insulated surface area to a
location external of said gripping portion.
14. The surgical tool of claim 13, further comprising a locking element
rotatable around said longitudinal axis of said needle assembly from a first position
that retains said needle assembly in said handle assembly to a second position that
allows removal of said needle assembly from said handle assembly.
15. The surgical tool of claim 13, wherein said handle assembly includes a
receptacle including an electrical contact for electrically engaging said proximal
portion of said needle assembly and electrically coupling said needle assembly with
said lead.

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16. The surgical tool of claim 13, wherein said needle assembly includes a
stylet removably received in a lumen of an outer cannula, said stylet including a
proximal end hub positionable in proximal abutting engagement with a proximal end
connection member of said cannula when said needle assembly is received in said
handle assembly.
17. The surgical tool of claim 16, wherein said electrically conductive
portion includes a distal end of said stylet and said conductive path extends along a
shaft of said stylet.
18. The surgical tool of claim 17, wherein cannula includes said insulated
surface area about an outer surface thereof.
19. The surgical tool of claim 13, wherein said major dimension is at least
50% greater than said minor dimension.
20. The surgical tool of claim 13, wherein said gripping portion of said
handle assembly includes continuously curved outer surfaces along a proximal end of
said handle assembly providing an anatomical fit at interfaces with a user's hand
along said major dimension.
21. The tool of claim 13, wherein said insulated surface area of said handle
assembly is in an overlapping arrangement with said insulated surface area of said
needle assembly.
22. A surgical method for accessing at least one vertebra of the spinal
column, comprising:
inserting a needle assembly through tissue to the at least one vertebra;
delivering an electrical signal to a distal end of the needle assembly while
inserting the needle assembly and insulating the needle assembly from tissue proximal
of the distal end;
monitoring the proximity of neural elements to the distal end;
engaging the distal end of the needle assembly to the at least one vertebra; and
removing a handle assembly mounted to a proximal end of the needle
assembly.
23. The method of claim 22, further comprising;

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removing a stylet from the needle assembly while maintaining an outer
cannula of the needle assembly in engagement with the vertebra.
24. The method of claim 23, further comprising:
positioning a guidewire through the cannula;
engaging the guidewire to the at least one vertebra; and
removing the outer cannula.
25. The method of claim 22, wherein the needle assembly extends along a
longitudinal axis and the handle assembly includes a gripping portion having a major
dimension and a minor dimension, the major dimension being at least 50% greater
than the minor dimension, the major and minor dimensions being measured
orthogonally to the longitudinal axis and to one another.
26. The method of claim 25, wherein an electrical lead extends through the
handle assembly along said major dimension and is electrically engageable to the
proximal end of the needle assembly within the handle assembly.

A surgical needle assembly (30) for penetrating soft and hard tissues of
a patient includes a handle assembly (80) removably coupled to the needle
assembly (30). The needle assembly (30) is electrically coupled to an
electrical signal source. The surgical tool (20) includes an electrically
conductive portion in communication with an un-insulated distal end of the
needle assembly (30), and an insulated portion extending from the distal end
to the handle assembly (80).

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=r6usoARcCn7AFGDfUr5vxQ==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 269510
Indian Patent Application Number 2871/KOLNP/2007
PG Journal Number 44/2015
Publication Date 30-Oct-2015
Grant Date 26-Oct-2015
Date of Filing 06-Aug-2007
Name of Patentee WARSAW ORTHOPEDIC, INC.
Applicant Address 2500 SILVEUS CROSSING WARSAW INDIANA
Inventors:
# Inventor's Name Inventor's Address
1 ADCOX, WILLIAM, K. 164 HARBOR VILLAGE DRIVE, MEMPHIS, TENNESSEE 38103
2 POND, JOHN, D. 2106 CORNWALL STREET, GERMANTOWN, TENNESSEE 38138
PCT International Classification Number A61B 18/14
PCT International Application Number PCT/US2006/003031
PCT International Filing date 2006-01-31
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/047,358 2005-01-31 U.S.A.