Note: Descriptions are shown in the official language in which they were submitted.
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
APPARATUS AND METHOD FOR IMAGE GUIDED INSERTION AND
REMOVAL OF A CANNULA OR NEEDLE
PRIORITY CLAIM
[0001] This application is claims priority to U.S. provisional patent
application
serial number 60/621,349 filed October 22, 2004.
[0001] This application is a continuation-in-part of and claims priority to
U.S.
patent application filed August 26, 2005 under U.S. Express Mail No.
EV509173452US..
[0002] This application claims priority to and is a continuation-in-part of
U.S.
Patent application serial number 11/119,355 filed April 29, 2005, which claims
priority to
U.S. provisional patent application serial number 60/566,127 filed April 30,
2004. This
application also claims priority to and is a continuation-in-part of U.S.
Patent application
serial number 10/701,955 filed November 5, 2003, which in turn claims priority
to and is
a continuation-in-part of U.S. Patent application serial number 10/443,126
filed May 20,
2003.
[0003] This application claims priority to and is a continuation-in-part of
U.S.
Patent application serial number 11/061,867 filed February 17, 2005, which
claims
priority to U.S. provisional patent application serial number 60/545,576 filed
February
-1-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
17, 2004 and U.S. provisional patent application serial number 60/566,818
filed April 30,
2004.
[0004] This application is also a continuation-in-part of and claims priority
to
U.S. patent application serial number 10/704,966 filed November 10, 2004.
[0005] This application is a continuation-in-part of and claims priority to
PCT
application serial number PCT/US03/24368 filed August 1, 2003, which claims
priority
to U.S. provisional patent application serial number 60/423,881 filed November
5, 2002
and U.S. provisional patent application serial number 60/400,624 filed August
2, 2002.
[0006] This application is also a continuation-in-part of and claims priority
to
PCT Application Serial No. PCT/US03/14785 filed May 9, 2003, which is a
continuation
of U.S. Patent application serial number 10/165,556 filed June 7, 2002.
[0007] This application is also a continuation-in-part of and claims priority
to
U.S. patent application serial number 10/888,735 filed July 9, 2004.
[0008] This application is also a continuation-in-part of and claims priority
to
U.S. patent application serial number 10/633,186 filed July 31, 2003 which
claims
priority to U.S. provisional patent application serial number 60/423,881 filed
November
5, 2002 and to U.S. patent application serial number 10/443,126 filed May 20,
2003
which claims priority to U.S. provisional patent application serial number
60/423,881
filed November 5, 2002 and to U.S. provisional application 60/400,624 filed
August 2,
2002. This application also claims priority to U.S. provisional patent
application serial
number 60/470,525 filed May 12, 2003, and to U.S. patent application serial
number
10/165,556 filed June 7, 2002. All of the above applications are herein
incorporated by
reference in their entirety as if fully set forth herein.
FIELD OF THE INVENTION
[0009] This invention relates to a magnetic system for manipulating the
placement of a needle or cannula in a biologic subject.
BACKGROUND OF THE INVENTION
[0010] Unsuccessful insertion and/or removal of a cannula, a needle, or other
similar devices into vascular tissue may cause vascular wall damage that may
lead to
-2-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
serious. complications or even death. Image guided placement of a cannula or
needle into
the vascular tissue reduces the risk of injury and increases the confidence of
healthcare
providers in using the foregoing devices. Current image guided placement
methods
generally use a guidance system having a mechanical means for holding specific
cannula
or needle sizes. The motion and force required to disengage the cannula from
the
guidance systein may, however, contribute to a vessel wall injury, which may
result in
extravasation. Complications arising from extravasation resulting in morbidity
are well
documented.
SUMMARY OF THE INVENTION
[0011] This invention relates to a magnetic system for manipulating the
placement of a needle or cannula for the purposes of positioning via image
devices into
an artery, vein, or other body cavity and releasing the cannula once the
placement is
successfully completed.
[0012] The invention provides a means for holding a selected cannula such that
the cannula is controllably restricted in motion in all but one line, but
still able to slide
along that line relatively freely. The motion restricting force may be
selectively varied,
thereby allowing an unrestricted separation of the cannula and the
holding/guide device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Embodiments of the present invention are described in detail below with
reference to the following drawings.
[0014] FIGURE 1 is a cross-sectional view of a first einbodiment;
[0015] FIGURE 1 B is an alternate embodiment of the first embodiment;
[0016] FIGURE 1C is a plan view of the first embodiment;
[0017] FIGURE 1D is a plan view of another embodiment;
[0018] FIGURE lE is a plan view of yet another embodiment;
[0019] FIGURE 2A is a cross-sectional view of a second embodiment;
[0020] FIGURE 2B is a plan view of the second embodiment;
-3-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
[0021] FIGURE 3A is a cross-sectional view of an alternate embodiment of the
second embodiment;
[0022] FIGURE 3B is a plan view of the alternate embodiment of the second
embodiment;
[0023] FIGURE 4A is a third embodiment of the invention;
[0024] FIGURE 4B is a plan view of the third embodiment;
[0025] FIGURE 5A is an embodiment of a magnetic strip;
[0026] FIGURE 5B is an alternate embodiment of the magnetic strip;
[0027] FIGURE 6A is an embodiment of a magnetic guide assembly having the
embodiments of FIGURE 5A;
[0028] FIGURE 6B is an alternate embodiment of a magnetic guide assembly
having the magnetic strip embodiments of FIGURE 5B;
[0029] FIGURE 7A schematically depicts removing a strip from the device
depicted in FIGURE 6A;
[0030] FIGURE 7B is a progression of the strip removal of FIGURE 7A;
[0031] FIGURE 7C is a continuation of strip removal of FIGURE 7B;
[0032] FIGURE 7D is near complete removal of the strips from the magnetic
guidance device;
[0033] FIGURE 7E is an alternate arrangement of the magnetic strips to the
magnetic guidance device;
[0034] FIGURE 8A is a cross-section of a fifth embodiment in the form of a
magnet-ferrite core assembly;
[0035] FIGURE 8B depicts the assembly of FIGURE 8A in cross-section
holding a cannula in a gap;
[0036] FIGURE 8C depicts the assembly of FIGURE 8A in cross-section where
removal of the magnet causes release of the cannula;
[0037] FIGURE 9A is an alternate embodiment of the magnet-ferrite core
assembly of FIGURE 8A;
-4-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
[0038] FIGURE 9B depicts the alternate embodiment of FIGURE 9A
magnetically holding a cannula;
[0039] FIGURE 9C schematically shows in cross-section the release of the
cannula from the assembly of FIGURE 9A.
[0040] FIGURE D shows the complete release of the cannula from the assembly
of FIGURE 9A;
[0041] FIGURE 10A is an isometric view of the magnetic core assembly of
FIGURE 8A;
[0042] FIGURE lOB is a schematic isometric depiction of the operation of the
magnet core assembly of FIGURE 8A;
[0043] FIGURE 10C is a schematic depiction of the operation of the magnet
core assembly of FIGURE 8A;
[0044] FIGURE 11A is an alternate embodiment of an isometric view of the
alternate embodiment depicted in FIGURE 9A;
[0045] FIGURE 11B depicts an operation of the embodiment shown in
FIGURE 11A;
[0046] FIGURE 12A is an alternate embodiment of a pair of magnet core
assemblies of FIGURE 8A;
[0047] FIGURE 12B is an isometric view of a schematic operation of an
embodiment of FIGURE 12A;
[0048] FIGURE 13A is an isometric view schematically depicting an electro
magnetic embodiment of FIGURE 12A;
[0049] FIGURE 13B is an isometric view schematically depicting the
electromagnet of FIGURE 13A;
[0050] FIGURE 14 illustrates in a partial isometric and side view of a V-Block
configured needle guidance device mounted to an ultrasound transceiver;
[0051] FIGURE 15 illustrates in a partial isometric and side view of a magnet-
ferrite core configured needle guidance device mounted to an ultrasound
transceiver;
-5-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
[0052] FIGURE 16 is an alternate embodiment of FIGURE 8A for detachably
attaching a magnet-ferrite needle guidance to an ultrasound transducer
housing;
[0053] FIGURE 17 is an alternate embodiment of FIGURE 12A mounted to a
tranducer housing;
[0054] FIGURE 18A is a side view of an ultrasound scanner having a magnetic
guide assembly;
[0055] FIGURE 18B is an isometric view and exploded view of components of
the device of FIGURE 18A;
[0056] FIGURE 19A is a side view of alternate embodiment of FIGURE 18A
utilizing a rotating magnet;
[0057] FIGURE 19B is an isometric view and exploded view of components of
the device of FIGURE 19A;
[0058] FIGURE 20A is a side view of alternate embodiment of FIGURE 19A
utilizing a pulling magnet; and
[0059] FIGURE 20B is an isometric view and exploded view of components of
the device of FIGURE 20A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0002] The present invention relates to an apparatus and a method for image
guided insertion and removal of a cannula or needle. Many specific details of
certain
embodiments of the invention are set forth in the following description and in
FIGURES
1 through 20B to provide a thorough understanding of such embodiments. One
skilled in
the art, however, will understand that the present invention may have
additional
embodiments, or that the present invention may be practiced without several of
the details
described in the following description.
[0060] FIGURE 1A is a schematic cross-section view of a needle/cannula guide
device 10 according to an embodiment of the invention. The needle/cannula
guide
device 10 includes a V-block 12 that supports a needle or cannula 18. The V-
block 12
includes two opposing sections that are coupled to each other at an apex.
Magnetic
-6-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
strips 16 are positioned on an exterior portion of the V-block 12 that
magnetically retain
the cannula 18 within the V-block 12. Accordingly, the V-block 12 may be
fabricated
from a suitably non-magnetic material, so that magnetic fields generated by
the magnet
strips 16 retain the metal needle 18 in the V-block 12. The non-magnetic
material of the
V-block 12 may be comprised of a low friction polymeric material such as, for
example,
Teflon , Nylon , or Delrin . Alternatively, it may be comprised of a
ferromagnetic
material that may similarly convey the magnetic fields generated by the
magnets 16. The
magnets 16 may be fixedly coupled to the V-block 12. Alternately, the magnets
16 may
be removably coupled to the V-block 12. .
[0061] FIGURE 1B is a schematic cross-section view of a needle/cannula guide
device 10A according to another einbodiment of the invention. Many of the
details of the
present embodiment have been described in detail in connection with the
embodiment
shown in FIGURE 1A, and in the interest of brevity, will not be described
further. The
guide device 10A includes a foil wrapper 20 or other suitable wrapper
materials that
substantially encloses the cannula 18. The wrapper 20 may be subjected to
sterilization
procedures so that the assembly 10A may be sterilized by autoclaving,
irradiation, or
other known chemical processes. The foil wrapper 20 is generally sealably
coupled to the
V-block 12 so that the cannula 18 is substantially isolated from contaminants,
yet is
configured to be easily removed from the V-block 12.
[0062] FIGURES 1 C, D, and E illustrate alternate embodiments of the cannula
guide devices 10 and 10A, as shown in FIGURE lA and FIGURE 113, respectively.
FIGURE 1 C is a plan view of the devices 10 and 10A where the cannula 18 is
positioned
in the V-block 12 and is held in position by the magnets 16, which extend
uninterrupted
along a length of the V-block 12. FIGURE 1D is a plan view of the devices 10
and 10A
that shows a first set of magnets 16A positioned on first selected portions of
the V-block
12, and a second set of magnets 16B that are positioned on second selected
portions of the
V-block 12. As shown in FIGURE 1D, the second set 16B may be positioned
between
the first set 16A. FIGURE 1 E is a plan view of the devices 10 and 10A that
shows
-7-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
magnets 16A interruptably positioned on the V-block 12. Although the magnets
16, 16A
and 16B are generally depicted in FIGURE 1C, FIGURE 1 D AND FIGURE 1 E as
rectangular, it is understood that the magnets 16, 16A and 16B may have any
regular
shape.
[0063] FIGURES 2A and 2B are cross sectional and plan views, respectively, of
a cannula guide device 20A according to another embodiment of the invention.
In
FIGURE 2A, the V-block 12 includes four magnet strips 24, positioned on each
arm of
the V-block 12 that are used to generate a retaining force on the needle 18.
Referring now
also to FIGURE 2B, the placement of the magnets 24 on the V-block 12
advantageously
permit the V-block 12 to accommodate a variety of needle diameters.
[0064] FIGURES 3A and 3B are cross sectional and plan views, respectively, of
a cannula guide device 20B according to still another embodiment of the
invention. The
device 20B includes magnets 24B that are operable to generate an attractive
force that is
different from magnets 24A. Accordingly, the magnets 24B may generate a
greater
attractive force on the needle 18 than the magnets 24A. Alternately, the
magnets 24A
may generate a greater attractive than the magnets 24B.
[0065] FIGURES 4A and 4B are cross sectional and plan views, respectively, of
a cannula guide device 20C according to still yet another embodiment of the
invention.
The device 20C includes a unitary magnet strips 27 having regions that
generate different
attractive forces on the needle 18. Accordingly, the unitary magnetic strips
27 include a
first magnetic strip portion 26A and a second magnetic strip portion 26B. The
attractive
force generated by the portion 26A may be greater than the attractive force
generated by
the portion 26B, or the attractive force generated by the portion 26B may be
greater than
the attractive force generated by the portion 26A.
[0066] FIGURES 5A and 5B are isometric views, respectively, of magnetic
strips 30A and 30B that may be removably coupled to the V-block 12 (FIGURE
1A).
The magnetic strips 30A and 30B include a tab 34 configured to apply a pulling
force to
the strips 30A and 30B. Referring now in particular to FIGURE 5A, a unitary
magnetic
-8-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
element 32 is positioned on the strip 30A that generates a relatively uniform
attractive
force on the needle 18 (not shown). Magnetic strip 30B shown in FIGURE 5B
includes a
magnetic element 36 that also includes magnetic portions 36A and 36B that are
configured to generate different attractive forces on the needle 18 (not
shown). The
magnetic strips 30A and 30B may also include an adhesive material that is
operable to
retain the strips 30A and 30B onto external surfaces of the V-block 12.
[0067] FIGURES 6A and 6B are respective isometric views of needle guidance
devices 40A and 40B. In FIGURE 6A, the needle guidance device 40A includes the
magnetic strips 30A as shown in FIGURE 5A that are positioned on the exterior
of the V-
block 12. The attractive force of the magnetic strips 30A magnetically holds
the needle 18
within an inner portion of the V-block 12. In FIGURE 6B, the needle guidance
device
40B includes the magnetic strip 30B of FIGURE 5B positioned on the V-block 12.
[0068] FIGURES 7A-7E are isometric views of the needle guidance device 40A
that will be used to a method of using the needle guidance device 40A
according to
another embodiment of the invention. FIGURE 7A and FIGURE 7B show a first
selected
one of the magnetic strips 30A being progressively removed from the V-block
12. The
first selected one of the strips 30A may be removed by a user by grasping the
tab 34 and
applying a pulling force on the tab 34 in the direction shown. Accordingly,
the attractive
force on the needle 18 is also progressively reduced. A selected length of the
strip 30A
may be removed so that a desired attractive force acting on the needle 18 is
attained.
Referring now to FIGURE 7C, a second selected one of the strips 30A may be
removed
by grasping the tab 34 and applying a pulling force on the tab 34 in a
suitable direction.
As a result, the attractive force on the needle 18 is still further reduced.
Although
FIGURES 7A through 7C show a single magnetic strip applied to external
surfaces of the
V-block 12, more than one magnetic strip may be present on an external surface
of the
V-block 12.
-9-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
[0069] Referring now to FIGURE 7D, when the first selected strip and the
second selected strip are removed to a desired degree, the needle 18 may be
separated
from the V-block 12.
[0070] As shown in FIGURE 7E, the magnetic strips 30A may be positioned on
the V-block 12 so that the strips 30A are oriented oppositely to those shown
in FIGURES
7A through 7D.
[0071] FIGURES 8A-8C are respective cross sectional views of a needle
guidance device 50 according to yet another embodiment of the invention. The
needle
guidance device 50 includes a pair of opposing metal cores 54 having a gap 58A
and a
gap 58B between the ferromagnetic cores 54. The metal cores 54 are generally
semi-
circularly shaped and may be made of any metal or metal alloy suitable for
conveying a
magnetic field, such as a ferromagnetic or ferrite material. A magnet 56 is
removably
positionable within a selected one of the gaps 58A and 58B. For purposes of
illustration,
the magnet 56 is positioned in the gap 56A. When the magnet 56 is positioned
within a
selected one of the gaps 58A and 58B, a magnetic field is communicated along
the cores
54 from the gap 58A to the gap 58B. The gap 58B is configured to accept a
needle 18 so
that the needle 18 will be retained in the gap 58B by the magnetic fields
communicated
from gap 56A. As shown in FIGURE 8A, the lines of the magnetic force are
conveyed
across the space 58B. Referring briefly now to FIGURE 8B, the needle 18 is
held within
the gap 58B. Accordingly, the needle 18 will be retained within the gap 58B
while the
magnet 56 is positioned within gap 58A. The gap 58B progressively narrows to
accommodate needles having variable diameters. Turning now to FIGURE 8C, as
the
magnet 56 is moved outwardly from the gap 58A of the needle guidance device
50, the
magnetic field spanning the gap 58B is correspondingly reduced. Accordingly,
the needle
18 positioned within the gap 58B may be gradually released from the needle
guidance
device 50.
[0072] FIGURES 9A-9D are respective cross sectional views of a needle
guidance device 60 according to yet still another embodiment of the invention.
With
-10-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
reference now to FIGURE 9A, the needle guidance device 60 includes a magnet 66
that is
configured to be rotated within the gap 58A. In FIGURE 9A, the magnet 66 is
shown in a
first position so that the magnetic lines of force are communicated along the
ferromagnetic cores 54. Accordingly, a magnetic field is established within
the gap 58B,
so that the needle 18 is retained within the gap 58B, as shown in FIGURE 9B.
In Figure
9C, the magnet 66 is rotated to a second position so that the magnetic lines
of force are
generally directed away from the ferromagnetic cores 54. Accordingly, the
attractive
force that retains the needle 18 within the gap 58B is reduced so that the
needle 18 may
be moved away from the gap 58B.
[0073] FIGURE 10A is an isometric view of the needle guidance device 50 of
FIGURES 8A through 8C. In this schematic view, the needle 18 is held into the
gap 58B
by the magnetic field generated by the magnet 56. The needle 18 is retained
from moving
through the gap 58B and into an internal region of the device 50 by providing
beveled
walls within the gap 58B that have a minimum distance "d" so that the beveled
walls
interfere with further movement of the needle 18 through the gap 58B since the
distance
"d" is generally selected to be smaller than a diameter of the needle 18.
Referring now to
FIGURE lOB, method of disengagement of the needle 18 from the gap 58B is
shown.
The disengagement of the needle 18 from the needle guidance device 50includes
moving
the magnet 56 upwardly and away from the cores 54. Correspondingly, a
reduction in
magnetic holding force occurs within the gap 58B so that the needle 18may be
removed
from the needle guidance device 50.
[0074] FIGURE 10C shows an alternate method for disengagement of the
needle 18 from the needle guidance device 50. Moving the magnet 56
longitudinally
along the gap 58A so that the magnetic force across the gap 58B is
proportionately
reduced effects the disengagement of the needle 18. Depending upon the
relative strength
of the magnet 56, the composition of the cores 54 and the material used to
fabricate the
needle, a user removing the magnet 56 may find that the magnetic holding force
is
sufficiently reduced to permit non-injurious disengagement of the needle 18
from the gap
-11-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
58B of the needle guidance device 50 when the magnet 56 is only partially
disengaged
from the gap 58A. Alternately, the user may be required to completely remove
the
magnet 56 from the gap 58A in order to release the needle 18 from the device
50.
[0075] FIGURE 11A is an isometric view of the needle guidance device 60 that
shows the needle 18 held in position by the rotating magnet 66. In this case,
the rotatable
magnet 66 is in the vertical position within the gap 58A, and the magnetic
forces hold the
needle 18 within the gap 58B.
[0076] FIGURE 1lB shows a completion of the disengagement process from
FIGURE 1 lA. The rotatable magnet 66 is rotated to a horizontal position as
indicated by
the crosshatched arrow within the gap 58A. This rotation causes either a
reduction of
retentive magnetic forces spanning across the gap 58B or generation of
repulsive forces.
As indicated by the downward arrow, the needle 18 becomes disengagable from
the
needle guidance device 60 and eventually separates from the gap 58B.
[0077] FIGURE 12A is an isometric view of a needle guidance device 70,
according to another embodiment of the invention. The device 70 includes two
ferromagnetic core assemblies 54 that are longitudinally spaced apart and
share a
common movable permanent magnet 56 configured to engage respective gaps 58A in
the
core assemblies 54. The magnet 56 may either be slidably disengaged from each
ferromagnetic core assembly 54 either longitudinally or it may be removed from
the
gap 58A by moving the magnet 56 in a radial direction and away from the core
assemblies 54. In either event, the progressive removal of permanent magnet 56
from the
respective gaps 58A causes a progressive reduction in magnetic fields across
the
gaps 58B. Accordingly, a user may advantageously select a suitable retentive
force for
the needle 18.
[0078] FIGURE 12B shows a disengagement of the operation in the orthogonal
displacement. Here, the needle guidance device 70 is in a disengagement
process where
the permanent magnet 56 is removed 90 orthogonal to the spaces 58A, to each
ferrite
core assembly 54. Removal as previously mentioned of a permanent magnet 56
causes a
-12-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
diminution magnetic retentive forces across the gap 58B resulting in a
progressively
easier disengagement force to be affected to the needle 18.
[0079] FIGURE 13A shows a needle guidance 80 being an electromagnetic
alternate embodiment to the permanent magnet embodiment 70. This
electromagnetic
embodiment 80 includes a DC power assembly that has a power source 82, a
variable
resistor 84 connected to the power source 82, in communication with a coil
winding (not
shown-see FIGURE 13B below) electrically connected with the source 82 and
resistor
84 via a wire 86. The wire 86 is connected with the coil winding (not shown)
that is
wrapped within the groove 158 of the electromagnet 156. The electromagnet 156
is a
non-permanent electromagnet that respectfully occupies the spaces 58A of metal
cores 54. The dashed arrow 84A within the variable resistor 84 shows a
resistor position
when there is sufficient power that is delivered to the core winding occupying
the grove
158 to induce a magnetic field of sufficient strength to hold the needle 18
across
respective gaps 58B of each iron or other metal core assembly 54 that is able
to convey
the magnetic flux fields generated by the electromagnet 156. Reducing the
power
indicated by the solid arrow 84B resistor position progressively causes a
reduction of
magnetic force due to the diminution of current and/or voltage applied to the
windings occupying the grove 158. Eventually the magnetic power is
progressively
lessened such that an applied disengagement force by a user permits the
removal or non-
injurious disengagement of the needle 18, as indicated by the downward arrow,
from the
gaps 58B of the guidance device 80.
[0080] FIGURE 13B is an isometric view schematically depicting the
electromagnet of FIGURE 13A. Within the grooves 158 of the he electromagnet
156 is a
coil winding 88. Application of electrical power by the DC power supply 82
through the
variable resistor 84 results in a magnetic force generated by the
electromagnet 156 in
proportion to the amount of electrical power delivered to the coil winding 88.
North, N
and South, S poles are formed along the electromagnet 156. As the power is
gradually
-13-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
lessened between the 84A and 84B resistor positions, the retentive magnetic
force field
generated along the electromagnet 156 is accordingly lessened.
[0081] As previously described for the removal of the magnetic strip
embodiments and the permanent magnets and the electromagnet needle guidance
devices
as previously described provides a means for holding a selected cannula such
that the
cannula is controllably restricted in motion substantially along one
dimension. The user
may either manipulate the amount of magnetic strips to vary the magnetic power
by the
permanent magnets or adjust power to electromagnets so that a user may
progressively
overcome the retentive forces still applied to the needle 18 and effect the
extraction or
disengageinent of the needle 18 from the respective needle guidance devices in
a non-
injurious way from a patient or other subject.
[0082] FIGURES 14-20B are partial isometric views that depict various
embodiments of the present invention coupled to an ultrasound transceiver 100.
In the
description that follows, it is understood that the various embodiments may be
removably
coupled to the ultrasound transceiver 100, or they may be permanently coupled
to the
transceiver 100. It is also understood that, although an ultrasound
transceiver is described
in the following description and shown in the following figures, the various
embodiments
may also be incorporated into other imaging devices.
[0083] FIGURE 14 is a partial isometric side viewthe V-Block 40A of FIGURE
6A and FIGURE 6B coupled to an ultrasound transceiver 101 to form an assembly
100.
The ultrasound transceiver 101 has the needle guidance device 40A coupled to a
transducer housing 104 of the transceiver 101 using a bridge 108. The needle
guidance
device 40A may be fixedly coupled to the housing 104, or the device 40A may be
removably coupled to the housing 104. In either case, thetransceiver 100 also
includes a
trigger 102, a display 103, a handle 106, and a transducer dome 112. Upon
pressing the
trigger 102, an ultrasound scancone 116 emanates from the transducer dome 112
that
penetrates a subject or patient. The scancone 116 is comprised of a radial
array of scan
planes 118. Within the scanplane 118 are scanlines (not shown) that may be
evenly or
-14-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
unevenly spaced. Alternatively, the scancone 116 may be comprised of an array
of
wedged distributed scancones or an array of 3D-distributed scanlines that are
not
necessarily confined to a given scan plane 118. As shown, the scancone 116 is
radiates
about the transducer axis 11 that bisects the transducer housing 104 and dome
112.
[0084] FIGURE 15 is a partial isometric, side view of the needle guidance
device 50 of FIGURE 8A, FIGURE 8B and FIGURE 8C coupled to the ultrasound
transceiver 101 to form an assembly 120. The ultrasound transceiver 101 has
the needle
guidance device 50 mounted to the transducer housing 104 using the bridge 108
of
FIGURE 14. The device 50 may be fixedly or removably coupled to the housing
104. A
scan cone 116 is similarly projected from the transceiver 101. Various aiming
aids may
be placed on the needle guidance device 50 to assist a user in aiming the
insertion of a
needle that is held by a magnetic force to slide within the gap 58B.
[0085] FIGURE 16 is a partial isometric view of a needle guidance device 90
that may be removably coupled to the housing 104 of an ultrasound transceiver
101,
according to another embodiment of the invention. The needle guidance device
90 is
attached to an engagement wedge 92. The engagement wedge 92 slidably and
removably
attaches with the slot holder 94 that is positioned on a selected portion of
the housing 104.
Various aiming aids may be placed on the needle guidance device 90 to assist a
user in
aiming the insertion of a needle that is held by a magnetic force to slide
within the
gap 58B.
[0086] FIGURE 17 is a partial isometric view of a needle guidance device 130
according to another embodiment of the invention. The device 130 is configured
to be
positioned within a transceiver housing 132. A pair of magnets 134 and 136 are
positioned on a rotational shaft 137 that projects into the housing 132. The
magnets 134
and 136 provide an attractive force on the needle 18 when the magnets 134 and
136 are
aligned with the needle 18. When the magnets 134 and 136 are rotated away from
alignment (by manually rotating a wheel 139 coupled to the shaft 138) with the
needle 18,
-15-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
the attractive force on the needle 18 is reduced, thus allowing the needle 18
to be moved
relative to the housing 132. .
[0087] FIGURE 18A is a side view of an ultrasound scanner having a magnetic
guide assembly 144, according to an embodiment of the invention. The guidance
assembly 144 includes the transceiver 101 in which a needle 18 with reservoir
19 is held
within a ferrite housing 144. The ferrite housing 144 is secured to transducer
housing 104
by a clip-on clasp 142.
[0088] FIGURE 18B is an isometric view and exploded view of components of
the assembly 144 of FIGURE 18A. In the exploded view, the guidance assembly
144 is
seen in greater detail. The ferrite housing 144 receives ferrite cores 146 and
150.
Rotable within the space defined by the ferrite core 146 and gap 58A of
ferrite cores 150
is a rotatable magnet 148. Located between the clip-on clasp 142 and the
ferrite housing
144 is an articulating bridge 143. The articulating bridge 143 allows the user
to alter the
entry angle of the needle 18 into the patient relative to the transducer axis
11 as illustrated
in FIGURE 14. Rotating the magnet 148 alters the magnetic holding power to gap
58B
between ferrite cores 150.
[0089] FIGURE 19A is a side view of alternate embodiment shown in
FIGURE 18A that uses a sliding magnet. A guidance assembly 170 includes the
transceiver 101 in which a needle 18 with reservoir 19 is held within a
ferrite housing
145. The ferrite housing 145 is secured to transducer housing 104 by a clip-on
clasp 142
and articulating bridge 143. The ferrite housing 145 is configured to receive
three
components.
[0090] FIGURE 19B is an isometric view and exploded view of the components
of the device 170 of FIGURE 19A. In the exploded view the guidance assembly
170 is
seen in greater detail. The ferrite housing 145 receives two ferrite cores 172
and a
slidable magnet 176. The slidable magnet 176 is moveable within the space 56A
defined
by the ferrite cores 172. Opposite the space 56A is space 56B that receives
the needle 18.
The articulating bridge 143 allows the user to alter the entry angle of the
needle 18 into
-16-
CA 02626226 2008-04-16
WO 2006/047554 PCT/US2005/038477
the patient or subject relative to the transducer axis 11 as illustrated in
FIGURE 14.
Sliding the magnet 176 alters the magnetic holding power to gap 58B between
ferrite
cores 172.
[0091] FIGURE 20A is a side view of alternate embodiment of the device 170
of FIGURE 19A utilizing a pulling magnet. A guidance assembly 180 includes the
transceiver 101 in which a needle 18 with reservoir 19 is held within a
ferrite housing
182. The ferrite housing 182 is secured to transducer housing 104 by a clip-on
clasp 142
and articulating bridge 143. The ferrite housing 145 is configured to receive
three
components.
[0092] FIGURE 20B is an isometric view and exploded view of components of
the device 180 of FIGURE 20A. In the exploded view the guidance assembly 180
is seen
in greater detail. The ferrite housing 182 receives two ferrite cores 188 and
a trigger
receiver 186. The trigger receiver 186 receivers the trigger 190 that has a
magnet frame
191. The magnet frame 191 retains the magnet 192. The magnet 192 is snap-
fitted into
the magnet frame 191 of the trigger 190. The magnet-loaded trigger 190 is
slidably
placed into the trigger receiver 186. The trigger receiver 186 guides the
magnet-loaded
trigger 190 within the gap 58B defined by the two ferrite cores 188. Pulling
the magnet-
loaded trigger 190 alters the magnetic holding power to gap 58B receiving the
needle 18
located opposite the gap 58A between ferrite cores 188.
[0093] While various embodiments of the invention has been illustrated and
described, as noted above, many changes can be made without departing from the
spirit
and scope of the invention. For example, electromagnetic strips may be
removably
attached to V-blocks and the magnetic power controlled by an electric circuit
applied to
the electromagnetic strips. Permanent magnets used in the various embodiments
may be
of any metal able to generate and communicate a magnetic force, for example,
Iron, Iron
alloys, and Neodymnium based magnets. Accordingly, the scope of the invention
is not
limited by the disclosure of the preferred embodiment. Instead, the invention
should be
determined entirely by reference to the claims that follow.
-17-
