U.S. patent application number 11/258592 was filed with the patent office on 2007-05-03 for apparatus and method for image guided insertion and removal of a cannula or needle.
Invention is credited to Russell A. Garrison, Gerald McMorrow, Steven J. Shankle.
Application Number | 20070100236 11/258592 |
Document ID | / |
Family ID | 29710469 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070100236 |
Kind Code |
A1 |
McMorrow; Gerald ; et
al. |
May 3, 2007 |
Apparatus and method for image guided insertion and removal of a
cannula or needle
Abstract
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 the line relatively freely. The motion
restricting force may be selectively varied, thereby allowing an
unrestricted separation of the cannula and holding/guide
device.
Inventors: |
McMorrow; Gerald; (Kirkland,
WA) ; Shankle; Steven J.; (Kirkland, WA) ;
Garrison; Russell A.; (Redmond, WA) |
Correspondence
Address: |
BLACK LOWE & GRAHAM, PLLC
701 FIFTH AVENUE
SUITE 4800
SEATTLE
WA
98104
US
|
Family ID: |
29710469 |
Appl. No.: |
11/258592 |
Filed: |
October 24, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/US03/24368 |
Aug 1, 2003 |
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11258592 |
Oct 24, 2005 |
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PCT/US03/14785 |
May 9, 2003 |
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11258592 |
Oct 24, 2005 |
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|
10165556 |
Jun 7, 2002 |
6676605 |
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PCT/US03/14785 |
May 9, 2003 |
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10888735 |
Jul 9, 2004 |
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11258592 |
Oct 24, 2005 |
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10633186 |
Jul 31, 2003 |
7004904 |
|
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11258592 |
Oct 24, 2005 |
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10443126 |
May 20, 2003 |
7041059 |
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10633186 |
Jul 31, 2003 |
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60621349 |
Oct 22, 2004 |
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60423881 |
Nov 5, 2002 |
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60423881 |
Nov 5, 2002 |
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60400624 |
Aug 2, 2002 |
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60470525 |
May 12, 2003 |
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Current U.S.
Class: |
600/437 ;
600/449 |
Current CPC
Class: |
A61B 8/0833 20130101;
A61B 2017/00876 20130101; G01S 7/52053 20130101; A61B 5/204
20130101; A61B 8/0841 20130101; G06T 7/62 20170101; A61B 8/4455
20130101; G01S 7/52085 20130101; A61B 8/0858 20130101; A61B 34/10
20160201; G06T 7/12 20170101; A61B 17/3403 20130101; G01S 15/8909
20130101; G06T 2207/10136 20130101; G06T 2207/30044 20130101; G01S
7/52036 20130101; A61B 8/483 20130101; A61B 2090/378 20160201; G06T
2207/10132 20130101; G06T 7/0012 20130101; G06T 2207/20061
20130101; A61B 2017/3413 20130101; G06T 7/11 20170101; A61B 5/1075
20130101; G06T 2207/30004 20130101; A61B 2017/00477 20130101 |
Class at
Publication: |
600/437 ;
600/449 |
International
Class: |
A61B 8/00 20060101
A61B008/00 |
Claims
1. An imaging guided device for placing a cannula attached to a
magnetically responsive needle at a targeted location, the device
comprising: an imaging probe operationally configured with imaging
system to present an image; an attachment connected with the
imaging probe, the attachment comprising: a block having at least
one magnet to releasably retain the needle by alternating the
magnetic force of the magnet applied to the needle, wherein the
needle is inserted to and removed from the targeted location as
determined in the image at a user adjusted retentive magnetic
force, leaving the cannula in place at the targeted location after
removal of the needle.
2. The device of claim 1, wherein the magnet comprises at least one
removable strip.
3. The device of claim 1, wherein the magnet comprises two
removable strips approximately orthogonal to each other.
4. The device of claim 3, wherein the removable strip includes a
plurality of magnets having substantially similar magnetic
power.
5. The device of claim 3, wherein the removable strip includes a
plurality of magnets having substantially different magnetic
power.
6. The device of claim 5, wherein the removable strip includes an
inner magnetic core and an outer magnetic perimeter.
7. The device of claim 1, wherein the magnet includes a ferrite
core having a first gap to engage a moveable magnet bar and a
second gap to receive the magnetically responsive needle.
8. The device of claim 7, wherein the moveable magnet bar is
slidable within the first gap.
9. The device of claim 7, wherein the moveable magnet bar is
translocatable from the first gap.
10. The device of claim 7, wherein the moveable magnet bar is
rotatable within the first gap.
11. The device of claim 1, wherein the magnet includes a magnetic
core having a first gap to engage a moveable magnet bar and a
second gap to receive the magnetically responsive needle.
12. The device of claim 11, wherein the moveable magnet bar is
rotatable within the first gap.
Description
PRIORITY CLAIM
[0001] This application is claims priority to U.S. provisional
patent application Ser. No. 60/621,349 filed Oct. 22, 2004.
[0002] This application is a continuation-in-part of and claims
priority to U.S. patent application filed Aug. 26, 2005 under U.S.
Express Mail No. EV509173452US.
[0003] This application claims priority to and is a
continuation-in-part of U.S. patent application Ser. No. 11/119,355
filed Apr. 29, 2005, which claims priority to U.S. provisional
patent application Ser. No. 60/566,127 filed Apr. 30, 2004. This
application also claims priority to and is a continuation-in-part
of U.S. patent application Ser. No. 10/701,955 filed Nov. 5, 2003,
which in turn claims priority to and is a continuation-in-part of
U.S. patent application Ser. No. 10/443,126 filed May 20, 2003.
[0004] This application claims priority to and is a
continuation-in-part of U.S. patent application Ser. No. 11/061,867
filed Feb. 17, 2005, which claims priority to U.S. provisional
patent application Ser. No. 60/545,576 filed Feb. 17, 2004 and U.S.
provisional patent application Ser. No. 60/566,818 filed Apr. 30,
2004.
[0005] This application is also a continuation-in-part of and
claims priority to U.S. patent application Ser. No. 10/704,966
filed Nov. 10, 2004.
[0006] This application is a continuation-in-part of and claims
priority to PCT application serial number PCT/US03/24368 filed Aug.
1, 2003, which claims priority to U.S. provisional patent
application Ser. No. 60/423,881 filed Nov. 5, 2002 and U.S.
provisional patent application Ser. No. 60/400,624 filed Aug. 2,
2002.
[0007] 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
Ser. No. 10/165,556 filed Jun. 7, 2002.
[0008] This application is also a continuation-in-part of and
claims priority to U.S. patent application Ser. No. 10/888,735
filed Jul. 9, 2004.
[0009] This application is also a continuation-in-part of and
claims priority to U.S. patent application Ser. No. 10/633,186
filed Jul. 31, 2003 which claims priority to U.S. provisional
patent application Ser. No. 60/423,881 filed Nov. 5, 2002 and to
U.S. patent application Ser. No. 10/443,126 filed May 20, 2003
which claims priority to U.S. provisional patent application Ser.
No. 60/423,881 filed Nov. 5, 2002 and to U.S. provisional
application 60/400,624 filed Aug. 2, 2002. This application also
claims priority to U.S. provisional patent application Ser. No.
60/470,525 filed May 12, 2003, and to U.S. patent application Ser.
No. 10/165,556 filed Jun. 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
[0010] This invention relates to a magnetic system for manipulating
the placement of a needle or cannula in a biologic subject.
BACKGROUND OF THE INVENTION
[0011] 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 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 system 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
[0012] 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.
[0013] 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
[0014] Embodiments of the present invention are described in detail
below with reference to the following drawings.
[0015] FIG. 1 is a cross-sectional view of a first embodiment;
[0016] FIG. 1B is an alternate embodiment of the first
embodiment;
[0017] FIG. 1C is a plan view of the first embodiment;
[0018] FIG. 1D is a plan view of another embodiment;
[0019] FIG. 1E is a plan view of yet another embodiment;
[0020] FIG. 2A is a cross-sectional view of a second
embodiment;
[0021] FIG. 2B is a plan view of the second embodiment;
[0022] FIG. 3A is a cross-sectional view of an alternate embodiment
of the second embodiment;
[0023] FIG. 3B is a plan view of the alternate embodiment of the
second embodiment;
[0024] FIG. 4A is a third embodiment of the invention;
[0025] FIG. 4B is a plan view of the third embodiment;
[0026] FIG. 5A is an embodiment of a magnetic strip;
[0027] FIG. 5B is an alternate embodiment of the magnetic
strip;
[0028] FIG. 6A is an embodiment of a magnetic guide assembly having
the embodiments of FIG. 5A;
[0029] FIG. 6B is an alternate embodiment of a magnetic guide
assembly having the magnetic strip embodiments of FIG. 5B;
[0030] FIG. 7A schematically depicts removing a strip from the
device depicted in FIG. 6A;
[0031] FIG. 7B is a progression of the strip removal of FIG.
7A;
[0032] FIG. 7C is a continuation of strip removal of FIG. 7B;
[0033] FIG. 7D is near complete removal of the strips from the
magnetic guidance device;
[0034] FIG. 7E is an alternate arrangement of the magnetic strips
to the magnetic guidance device;
[0035] FIG. 8A is a cross-section of a fifth embodiment in the form
of a magnet-ferrite core assembly;
[0036] FIG. 8B depicts the assembly of FIG. 8A in cross-section
holding a cannula in a gap;
[0037] FIG. 8C depicts the assembly of FIG. 8A in cross-section
where removal of the magnet causes release of the cannula;
[0038] FIG. 9A is an alternate embodiment of the magnet-ferrite
core assembly of FIG. 8A;
[0039] FIG. 9B depicts the alternate embodiment of FIG. 9A
magnetically holding a cannula;
[0040] FIG. 9C schematically shows in cross-section the release of
the cannula from the assembly of FIG. 9A.
[0041] FIG. D shows the complete release of the cannula from the
assembly of FIG. 9A;
[0042] FIG. 10A is an isometric view of the magnetic core assembly
of FIG. 8A;
[0043] FIG. 10B is a schematic isometric depiction of the operation
of the magnet core assembly of FIG. 8A;
[0044] FIG. 10C is a schematic depiction of the operation of the
magnet core assembly of FIG. 8A;
[0045] FIG. 11A is an alternate embodiment of an isometric view of
the alternate embodiment depicted in FIG. 9A;
[0046] FIG. 11B depicts an operation of the embodiment shown in
FIG. 11A;
[0047] FIG. 12A is an alternate embodiment of a pair of magnet core
assemblies of FIG. 8A;
[0048] FIG. 12B is an isometric view of a schematic operation of an
embodiment of FIG. 12A;
[0049] FIG. 13A is an isometric view schematically depicting an
electro magnetic embodiment of FIG. 12A;
[0050] FIG. 13B is an isometric view schematically depicting the
electromagnet of FIG. 13A;
[0051] FIG. 14 illustrates in a partial isometric and side view of
a V-Block configured needle guidance device mounted to an
ultrasound transceiver;
[0052] FIG. 15 illustrates in a partial isometric and side view of
a magnet-ferrite core configured needle guidance device mounted to
an ultrasound transceiver;
[0053] FIG. 16 is an alternate embodiment of FIG. 8A for detachably
attaching a magnet-ferrite needle guidance to an ultrasound
transducer housing;
[0054] FIG. 17 is an alternate embodiment of FIG. 12A mounted to a
tranducer housing;
[0055] FIG. 18A is a side view of an ultrasound scanner having a
magnetic guide assembly;
[0056] FIG. 18B is an isometric view and exploded view of
components of the device of FIG. 18A;
[0057] FIG. 19A is a side view of alternate embodiment of FIG. 18A
utilizing a rotating magnet;
[0058] FIG. 19B is an isometric view and exploded view of
components of the device of FIG. 19A;
[0059] FIG. 20A is a side view of alternate embodiment of FIG. 19A
utilizing a pulling magnet; and
[0060] FIG. 20B is an isometric view and exploded view of
components of the device of FIG. 20A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] 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 FIGS. 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.
[0062] FIG. 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 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.RTM., Nylon.RTM., or Delrin.RTM.. 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.
[0063] FIG. 1B is a schematic cross-section view of a
needle/cannula guide device 10A according to another embodiment of
the invention. Many of the details of the present embodiment have
been described in detail in connection with the embodiment shown in
FIG. 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.
[0064] FIGS. 1C, D, and E illustrate alternate embodiments of the
cannula guide devices 10 and 10A, as shown in FIG. 1A and FIG. 1B,
respectively. FIG. 1C 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. FIG. 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 FIG. 1D, the second set 16B may be positioned
between the first set 16A. FIG. 1E is a plan view of the devices 10
and 10A that shows magnets 16A interruptably positioned on the
V-block 12. Although the magnets 16, 16A and 16B are generally
depicted in FIG. 1C, FIG. 1D AND FIG. 1E as rectangular, it is
understood that the magnets 16, 16A and 16B may have any regular
shape.
[0065] FIGS. 2A and 2B are cross sectional and plan views,
respectively, of a cannula guide device 20A according to another
embodiment of the invention. In FIG. 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 FIG. 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.
[0066] FIGS. 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.
[0067] FIGS. 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.
[0068] FIGS. 5A and 5B are isometric views, respectively, of
magnetic strips 30A and 30B that may be removably coupled to the
V-block 12 (FIG. 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 FIG. 5A, a unitary magnetic 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 FIG. 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.
[0069] FIGS. 6A and 6B are respective isometric views of needle
guidance devices 40A and 40B. In FIG. 6A, the needle guidance
device 40A includes the magnetic strips 30A as shown in FIG. 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 FIG. 6B,
the needle guidance device 40B includes the magnetic strip 30B of
FIG. 5B positioned on the V-block 12.
[0070] FIGS. 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. FIG. 7A and FIG. 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 FIG. 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 FIGS. 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.
[0071] Referring now to FIG. 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.
[0072] As shown in FIG. 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 FIGS. 7A through 7D.
[0073] FIGS. 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 FIG. 8A, the lines of
the magnetic force are conveyed across the space 58B. Referring
briefly now to FIG. 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 FIG. 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.
[0074] FIGS. 9A-9D are respective cross sectional views of a needle
guidance device 60 according to yet still another embodiment of the
invention. With reference now to FIG. 9A, the needle guidance
device 60 includes a magnet 66 that is configured to be rotated
within the gap 58A. In FIG. 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 FIG. 9B. In FIG. 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.
[0075] FIG. 10A is an isometric view of the needle guidance device
50 of FIGS. 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 FIG.
10B, method of disengagement of the needle 18 from the gap 58B is
shown. The disengagement of the needle 18 from the needle guidance
device 50 includes 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 18 may be removed from
the needle guidance device 50.
[0076] FIG. 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 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.
[0077] FIG. 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.
[0078] FIG. 11B shows a completion of the disengagement process
from FIG. 11A. 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.
[0079] FIG. 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.
[0080] FIG. 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.degree. orthogonal to the spaces 58A, to each ferrite core
assembly 54. Removal as previously mentioned of a permanent magnet
56 causes a diminution magnetic retentive forces across the gap 58B
resulting in a progressively easier disengagement force to be
affected to the needle 18.
[0081] FIG. 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
FIG. 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.
[0082] FIG. 13B is an isometric view schematically depicting the
electromagnet of FIG. 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 lessened between the
84A and 84B resistor positions, the retentive magnetic force field
generated along the electromagnet 156 is accordingly lessened.
[0083] 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 disengagement of the needle 18 from the
respective needle guidance devices in a non-injurious way from a
patient or other subject.
[0084] FIGS. 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.
[0085] FIG. 14 is a partial isometric side view the V-Block 40A of
FIG. 6A and FIG. 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, the
transceiver 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
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.
[0086] FIG. 15 is a partial isometric, side view of the needle
guidance device 50 of FIG. 8A, FIG. 8B and FIG. 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 FIG. 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.
[0087] FIG. 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.
[0088] FIG. 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, the attractive force on the needle 18 is reduced, thus
allowing the needle 18 to be moved relative to the housing 132.
[0089] FIG. 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.
[0090] FIG. 18B is an isometric view and exploded view of
components of the assembly 144 of FIG. 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 FIG. 14. Rotating the magnet 148 alters the
magnetic holding power to gap 58B between ferrite cores 150.
[0091] FIG. 19A is a side view of alternate embodiment shown in
FIG. 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.
[0092] FIG. 19B is an isometric view and exploded view of the
components of the device 170 of FIG. 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 the patient
or subject relative to the transducer axis 11 as illustrated in
FIG. 14. Sliding the magnet 176 alters the magnetic holding power
to gap 58B between ferrite cores 172.
[0093] FIG. 20A is a side view of alternate embodiment of the
device 170 of FIG. 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.
[0094] FIG. 20B is an isometric view and exploded view of
components of the device 180 of FIG. 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.
[0095] 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.
* * * * *