U.S. patent application number 12/813632 was filed with the patent office on 2011-02-24 for apparatus for capturing objects beyond an operative site utilizing a capture device delivered on a medical guide wire.
Invention is credited to Richard J. Arnott, Gerald G. Cano, Thomas G. Loebig.
Application Number | 20110046656 12/813632 |
Document ID | / |
Family ID | 21691974 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110046656 |
Kind Code |
A1 |
Arnott; Richard J. ; et
al. |
February 24, 2011 |
APPARATUS FOR CAPTURING OBJECTS BEYOND AN OPERATIVE SITE UTILIZING
A CAPTURE DEVICE DELIVERED ON A MEDICAL GUIDE WIRE
Abstract
An apparatus for removing a solid object from a body canal or
vessel includes a coil of wire configured to slidably receive a
guide wire and a sack having a mouth and a closed bottom opposite
the sack. A resilient frame is connected between the coil of wire
and the sack for biasing the mouth of the sack open around the coil
of wire. The resilient frame is positionable between a collapsed
state where the mouth of the sack is closed against the bias of the
resilient frame and a deployed state where the mouth of the sack is
biased open by the resilient frame.
Inventors: |
Arnott; Richard J.;
(Pittsburgh, PA) ; Cano; Gerald G.; (Export,
PA) ; Loebig; Thomas G.; (Pittsburgh, PA) |
Correspondence
Address: |
BLYNN L. SHIDELER;THE BLK LAW GROUP
3500 BROKKTREE ROAD, SUITE 200
WEXFORD
PA
15090
US
|
Family ID: |
21691974 |
Appl. No.: |
12/813632 |
Filed: |
June 11, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12423576 |
Apr 14, 2009 |
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12813632 |
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11128524 |
May 13, 2005 |
7537601 |
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12423576 |
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10000546 |
Oct 24, 2001 |
6893451 |
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11128524 |
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60247824 |
Nov 9, 2000 |
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60249534 |
Nov 17, 2000 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61F 2230/0006 20130101;
A61F 2/011 20200501; A61F 2/013 20130101; A61F 2002/018 20130101;
A61F 2230/008 20130101; A61F 2002/015 20130101; A61F 2230/0067
20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61F 2/01 20060101
A61F002/01 |
Claims
1. A method for deploying an apparatus for removing a solid object
from a patient's vasculature, the apparatus including a guide wire,
a resilient frame including a sack having a mouth and a closed
bottom opposite the mouth, the resilient frame being positionable
between a collapsed state where the mouth of the sack is closed
against the bias of the resilient frame and a deployed state where
the mouth of the sack is biased open by the resilient frame, a
flexible mounting member configured to slidably receive the guide
wire, the resilient frame being attached to the flexible mounting
member; a containment collar configured to slidably receive the
guide wire there through and to receive at least part of the
resilient frame therein; and a pull wire connected to the
containment collar, wherein the pull wire has a proximal end which
remains outside the body vessel during usage, the method including:
deploying the guide wire within the patient's vasculature; sliding
the flexible mounting member, resilient frame and containment
collar over the guide wire to position the resilient frame into a
target area in the patient's vasculature; and moving the pull wire
proximally relative to the resilient frame to retract the
containment collar from the resilient frame.
2. The method of claim 1, wherein the flexible mounting member is a
coil of wire.
3. The method of claim 1, wherein the guide wire includes a distal
stop.
4. The method of claim 3, wherein the step of sliding the mounting
member, resilient frame and containment collar over the guide wire
to position the resilient frame into a target area in the body
vessel includes abutting a distal end of the mounting member
against the distal stop of the guide wire.
5. The method of claim 1, wherein the resilient frame is adapted to
exert a force against the wall of the body vessel once
deployed.
6. The method of claim 1, wherein a portion of the pull wire has at
least one coiled section which wraps around the guide wire.
7. An apparatus for removing a solid object from a body canal or
vessel, the apparatus comprising: a guide wire; a sack having an
apex; control arms attached to said sack and configured to bias
said sack into an open position; wherein the improvement comprises
a flexible frame in the form of a cylinder defining a lumen
therethrough, said control arms and sack coupled to said flexible
frame and configured to move with said flexible frame along said
guide wire, said flexible cylinder frame being capable of rotation
or linear movement when positioned on said guide wire, said
flexible cylinder frame further configured to be firm axially, but
pliable laterally, such that said flexible cylinder frame can
conform to twists and bends taken by said guide wire during
manipulation and advancement of whereby said flexible cylinder
frame can bend and follow a path of said guide wire while avoiding
axial elongation of said flexible cylinder frame.
8. The apparatus of claim 7, wherein said guide wire includes a
proximal stop and a distal stop in spaced relation on said guide
wire; said flexible frame is received on said guide wire between
said proximal stop and said distal stop; and each said stop is
configured to avoid the slidable passage of said flexible frame
thereby.
9. The apparatus of claim 7, further comprising a containment
collar configured to slidably receive the guide wire therethrough
and to receive at least part of the flexible frame therein.
10. The apparatus of claim 7, further comprising a pull wire
connected to said containment collar.
11. An apparatus for removing a solid object from a body canal or
vessel, the apparatus comprising: A guide wire; a flexible frame
member configured to slidably receive the guide wire; a sack having
a mouth and a closed bottom opposite the mouth; a resilient frame
connected between the flexible frame member and the sack for
biasing the mouth of the sack open, the resilient frame
positionable between a collapsed state where the mouth of the sack
is closed against the bias of the resilient frame and a deployed
state where the mouth of the sack is biased open by the resilient
frame; a containment collar configured to slidably receive the
guide wire therethrough and to receive at least part of the
resilient frame therein; and a pull wire connected to the
containment collar, wherein in response to relative movement
between the flexible frame member and the pull wire, the resilient
frame is positionable between the collapsed state at least
partially inside the containment collar and the deployed state
outside the containment collar.
12. The apparatus as set forth in claim 11, wherein the flexible
frame member is firm axially and pliable laterally.
13. The apparatus as set forth in claim 11, wherein: the closed
bottom of the sack is connected to the flexible frame member
adjacent one end thereof; the resilient frame is connected to the
flexible frame member adjacent the end thereof opposite the closed
bottom of the sack.
14. The apparatus as set forth in claim 11, further including a
deployment catheter having a lumen configured to slidably receive
the guide wire, wherein: the deployment catheter has an end
configured to abut an end of the flexible frame member when the
flexible frame member is received on the guide wire.
15. The apparatus as set forth in claim 11, wherein the flexible
frame member is a helically wound spring.
16. The apparatus as set forth in claim 11, wherein the resilient
frame has a radiopaque thread wrapped around at least a portion of
the resilient frame to increase the radiopacity of the resilient
frame.
17. The apparatus as set forth in claim 11, wherein a portion of
the pull wire has at least one coiled section which wraps around
the guide wire.
18. The apparatus as set forth in claim 11, wherein a portion of
the pull wire has a plurality of spaced coiled sections which wrap
around the guide wire.
19. The apparatus as set forth in claim 11, wherein the containment
collar and pull wire are connected together by a tubular
member.
20. The apparatus as set forth in claim 19, wherein the tubular
member connecting the containment collar and pull wire is formed as
a coil of wire.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 12/423,576 filed Apr. 14, 2009 and which published on Sep.
10, 2009 as U.S. Patent Application Publication Number
2009-0228036. U.S. patent application Ser. No. 12/423,576 is a
continuation of U.S. patent application Ser. No. 11/128,524 filed
May 13, 2005 and which issued as U.S. Pat. No. 7,537,601. U.S.
patent application Ser. No. 11/128,524 is a continuation of U.S.
patent application Ser. No. 10/000,546 filed Oct. 21, 2001 and
which issued as U.S. Pat. No. 6,893,451. U.S. patent application
Ser. No. 10/000,546 claims priority from U.S. Provisional Patent
Application Ser. No. 60/247,824, filed Nov. 9, 2000, and U.S.
Provisional Patent Application Ser. No. 60/249,534, filed Nov. 17,
2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed to capturing objects
beyond an operative site in any of a variety of medical procedures
employed to treat any number of medical conditions in human and/or
animal patients.
[0004] 2. Background Information
[0005] In many medical procedures, objects are dislodged or
otherwise freed by the surgeon during the surgical procedure, and
it is useful and/or necessary to capture the dislodged and/or
otherwise freed object.
[0006] Although minimally invasive interventional medical therapies
in general, and minimally invasive endovascular therapy in
particular, are medical procedures where objects may be dislodged
or otherwise freed during the procedure, each has enjoyed
unprecedented expansion to treat patients because of the numerous
medical benefits associated with not having to enter the body
through more invasive surgical techniques. These benefits include,
but are not limited to, less trauma and/or scarring for patients,
less time to heal, less risk of infection and decreased hospital
stays, to name but a few.
[0007] More particularly, minimally invasive endovascular therapy
is often used to treat diseased vessels, e.g., arteries and veins.
With such therapy, small instruments are inserted into the vessels
through a puncture or access opening made in one of the vessels at
an entry site and are advanced through the circulatory system to an
operative site where the vessel has become diseased, and the
instruments are used to repair the diseased or operative site.
[0008] Typically, the goal of such therapy is to dilate full or
partial blockages of the diseased vessel. Such blockages may have
developed over time or may have developed quickly, as for example,
in response to an injury. One common source of such blockage is
thromboemboli which has formed in the vessel. Thrombus is an
aggregation of platelets, fibrin, clotting factors and cellular
components of blood that spontaneously form and attach on the
interior wall of a vein or artery, and thromboemboli are emboli of
thrombus which operate to partially or completely occlude the
interior or lumen of the blood or other vessel.
[0009] Techniques to open and/or maintain the dilation of the
partially or completely occluded lumen of blood or other vessels
include positioning a balloon across an obstruction or partially
occluded section of the vessel, inflating the balloon to compress
the build up (balloon angioplasty) and/or temporarily or
permanently inserting a tube-like support within the vessels to
keep the vessel open (stenting).
[0010] Minimally invasive endovascular therapy has the significant
advantage that it is less invasive than traditional surgical
techniques and causes less trauma to the patient. However, this
therapy is complicated by the fact that it can undesirably dislodge
or free particles/objects during the procedure as discussed above,
and in that the tools or instruments and workspace, e.g., the
interior of the vessels of the body, are in some cases extremely
small and close, and reaching the operative site with the tools is
very difficult in some instances due to the considerable branching
of the circulatory system that may occur between the entry site
into the blood vessel and the operative site. This therapy is
further complicated by the fact that the entry site is often far
from the operative site, as for example, where the entry site is in
the thigh at the femoral artery and the operative site is located
in the neck at the carotid artery. Even when the surgeon's
instruments have been properly advanced to the operative site,
manipulating the tools to perform their respective functions at the
operative site is often difficult for the surgeon due to many
factors including the close quarters at the operative site and the
distance between the entry site and the operative site.
[0011] One method and apparatus commonly used by surgeons to ensure
the tools reach the operative site is to first thread a simple
guide wire to or beyond the operative site. Thereafter, various
tools are threaded over the guide wire by the surgeon to reach the
operative site. It is an important aspect of such guide wires that
they must be easy to manipulate through the vessels, including in
certain cases, through lesions or areas of blockage in the vessel
by the surgeon. In addition to exhibiting sufficient resiliency so
as to be pushable in the vessel, the guide wire must exhibit
sufficient flexibility and maneuverability to enable the surgeon to
traverse the many twists and turns of the circulatory (or other)
system to reach the operative site.
[0012] An aspect of the ability for a surgeon to manipulate the
guide wire through the circulatory or other system is the guide
wire's "torquability". As defined herein, the term "torquability"
means that as the surgeon rotates the proximal region of the guide
wire that extends outside of the patient's body during the
advancement of the guide wire through the patient's blood or other
vessels to the operative site, the amount of rotation at the
proximal region of the guide wire is transmitted to the distal end
of the guide wire being inserted and advanced through the patient's
blood or other vessels to the operative site. A lack of correlation
between rotation at the proximal region of the guide wire and
rotation at the distal end of the guide wire is referred to as
reduced torquability and is undesirable. A high degree of
correlation is referred to as a high degree of torquability and is
desirable. As may be appreciated, it is most desirable for the
guide wire to have an exact correlation or high torquability
between the rotation applied proximally at the proximal region of
the guide wire and the rotation developed distally in the guide
wire, so that the surgeon can carefully control and direct the
medical guide wire. With known devices, there is considerable
difference between the amount of rotation applied at the proximal
region of the guide wire and the amount of rotation developed at
the distal end of the guide wire, making it very difficult for
surgeons to maneuver the distal end of the guide wire.
[0013] Even where the guide wire exhibits the desired torquability
characteristics, and the tools have been properly threaded to the
operative site and have been properly manipulated to perform their
respective functions at the operative site, there remains the
problem noted above, namely, that the process of dilating the
occlusion and/or inserting the stent may dislodge or free small
particles or objects, also known, among other things, as clots,
fragments, plaque, emboli, thromboemboli, etc. More particularly,
with respect to endovascular therapy, the term "embolic event" has
come to be used to describe complications where thrombus or plaque
is shed inadvertently from a lesion to migrate to smaller vessels
beyond the operative site to create a full or partial occlusion of
the lumen of the vessel or vessels. This is most undesirable and
can lead to many complications. Complications depend upon the site
in the body where such emboli lodge downstream of the operative
site, but may include stroke, myocardial infarction, kidney
failure, limb loss or even death. With increasing vigor, surgeons
have expressed the need to reduce the likelihood of such
complications so that protection against embolic events will become
a standard component of endovascular therapy.
[0014] Devices have been made in the art to capture objects,
including emboli, downstream of an operative site in medical
procedures, including endovascular therapy. Such devices generally
employ a capture device, such as a bag or filter, which has a
collapsed state and an expanded or deployed state. Typically, the
capture device is maintained in its collapsed state within
sheathing and is inserted into the blood or other vessel and is
threaded beyond the operative site. It is then ejected from the
sheathing whereupon it expands to its deployed state to capture the
objects dislodged or otherwise freed during the medical
procedure.
[0015] One device for removing clot or filtering particles from
blood is described in U.S. Pat. No. 4,723,549 to Wholey et al.,
which discloses a device for dilating occluded blood vessels. This
device includes a collapsible filter device positioned between a
dilating balloon and the distal end of the catheter. The filter
comprises a plurality of resilient ribs secured to the catheter
that extend axially toward the dilating balloon. Filter material is
secured to the ribs. The filter deploys as a balloon is inflated to
form a cup-shaped trap. An important limitation of the Wholey et
al. device appears to be that the filter does not seal around the
interior vessel wall. Thus, particles sought to be trapped in the
filter can instead undesirably pass between the filter and the
vessel wall and flow downstream in the circulatory system to
produce a blockage. Another limitation is that the device also
presents a large profile during positioning. Yet another limitation
appears to be that the device is difficult to construct.
[0016] U.S. Pat. No. 4,873,978 to Ginsburg discloses a vascular
catheter that includes a strainer device at its distal end. The
device is inserted into a vessel downstream from the treatment site
and advanced to a proximal downstream location. The filter is
contained in a sheath when closed. When pushed from the sheath, the
filter deploys such that its mouth spans the lumen of the vessel.
Deployment is by expansion of resilient tines to which the strainer
material is attached. Again, however, it appears that the filter
does not seal around the interior vessel wall, thus undesirably
allowing particles to bypass the filter by passing between the
filter and the vessel wall. The position of the mouth relative to
the sheath is also clinically limiting for the Ginsburg device.
[0017] U.S. Pat. No. 5,695,519 to Summers et al. discloses a
removable intravascular filter on a hollow guide wire for
entrapping and retaining emboli. The filter is deployable by
manipulation of an actuating wire that extends from the filter into
and through the hollow tube and out the proximal end. One
limitation with the Summers et al. device appears to be that its
filter material is not fully constrained. Therefore, during
positioning within a vessel, as the device is positioned through
and past a clot, the filter material can snag clot material
undesirably creating freely floating emboli. It is unclear if the
actuating wire can close the filter, and it appears in any event
that it will exert a pull force on the rim of the filter that could
tear the wire from the rim. Another limitation appears to be that
the device application is limited by the diameter of the tube
needed to contain the actuating wire.
[0018] U.S. Pat. No. 5,814,064 to Daniel et al. discloses an emboli
capture device on a guide wire. The filter material is coupled to a
distal portion of the guide wire and is expanded across the lumen
of a vessel by a fluid activated expandable member in communication
with a lumen running the length of the guide wire. One limitation
of the device appears to be that during positioning, as the device
is passed through and beyond the clot, filter material may interact
with the clot so as to undesirably dislodge material and produce
emboli. It is further believed that the device may also be
difficult to manufacture. Another limitation is that it is
difficult to determine the amount of fluid needed to expand the
member. A lack of control can rupture and tear the smaller vessels.
Thus, the Daniel et al. device would appear to be more compatible
with use in the larger vessels only.
[0019] PCT Publication No. WO 98/33443 discloses a removable
vascular filter wherein the filter material is fixed to cables or
spines mounted to a central guide wire. A movable core or fibers
inside the guide wire can be utilized to transition the cables or
spines from approximately parallel the guide wire to approximately
perpendicular the guide wire. A limitation of this device appears
to be that the filter does not seal around the interior vessel
wall. Thus, particles, e.g., emboli-forming materials, can
undesirably bypass the filter by passing between the filter and the
vessel wall. Another limitation appears to be that this
umbrella-type device is shallow when deployed so that, as it is
being closed for removal, the particles it was able to ensnare
could escape. Yet another limitation is that the frame is such that
the introduction profile presents a risk of generating emboli as
the device is passed through and beyond the clot, occlusion or
stenosis.
[0020] U.S. Pat. No. 5,769,816 to Barbut et al. discloses a device
for filtering blood within a blood vessel. The device is delivered
through a cannula and consists generally of a cone-shaped mesh with
apex attached to a central support and open edge attached to an
inflation seal that can be deflated or inflated. The seal is
deflated during delivery and when delivery is complete, it is
inflated to seal the filter around the lumen of the vessel.
Limitations of this device include that it is complex to
manufacture. Inflation and deflation of the seal adds additional
operative steps thus prolonging the operation and introducing the
issue again of control, e.g., of how much to inflate to obtain a
seal without causing damage to the vessel or other material. While
the device may be suitable for large vessels, such as the aorta, is
would be most difficult to scale for smaller vessels, such as the
carotid or the coronary arteries.
[0021] U.S. Pat. No. 5,549,626 to Miller et al. discloses a coaxial
filter device for removing particles from arteries and veins
consisting of an outer catheter that can be inserted into a blood
vessel and an inner catheter with a filter at its distal end. The
filter is a radially expandable receptacle made of an elastic mesh
structure of spring wires or plastic monofilaments. When pushed
from the distal end of the catheter, the filter deploys across the
vessel lumen. A syringe attached to the proximal end of the inner
catheter aspirates particles entrapped in the filter. One
limitation of this device appears to be that it is possible that
some particles will remain in the filter after aspiration such
that, when the filter is retracted into the outer catheter,
particles not aspirated are undesirably released into the
circulatory system.
[0022] U.S. Pat. No. 6,027,520 to Tsugita et al. discloses a method
and system for embolic protection consisting of a filter on a guide
wire coupled with a separate stent catheter deployed over the guide
wire. One limitation of the Tsugita et al. device is that the many
filter designs summarized in the patent generally lack a
controllable, conformable circumferential support in the mouth of
the filters to ensure they seal around the inside of a blood
vessel. Without such a seal, it is again possible for particulate
material to evade the filter by undesirably passing between the
filter and the vessel wall, whereupon the particulate material may
flow downstream of the operative or other site to produce full or
partial blockage of the vessels. Many of the Tsugita et al. filter
expansion devices utilize multiple struts to open the filter. These
are not desirable as they increase the profile of the device when
crossing a lesion, in turn, reducing the range of clinical cases on
which they can be used. Further, such designs add stiffness to the
region of the undeployed filter which can impede the surgeon's
ability to direct the guide wire through the complex twists and
turns of the circulatory system to the operative site, e.g., making
it difficult to direct the device into a branching vessel. Also,
the Tsugita et al. design is burdened by its use of a long
deployment sheath to hold the filter in a collapsed state and
direct it to the operative site. The Tsugita et al. sheath extends
from a hemostatic seal at the site of entry into the blood or other
vessel to the operative site (see column 7, lines 56-58. and also
column 8, lines 19-30 of the Tsugita et al. patent). This long
sheath, necessary in the Tsugita et al. design, significantly
impairs the ability to direct the guide wire through the
circulatory system to the operative site. Not only is such a sheath
an impairment to directing the guide wire around the twists and
turns of the circulatory system, but such a sheath also "loads" the
guide wire, which operates to significantly reduce the Tsugita et
al. system's torquability, greatly reducing the ability of the
surgeon to control the guide wire and guide it through tight
lesions.
[0023] At column 7, lines 28-32, Tsugita et al. states that its
stent may comprise a tube, sheet, wire, mesh or spring, and goes on
to state that such a stent can cover the plaque and substantially
permanently trap it between the stent and the wall of the vessel.
(see column 9, lines 55-58 of the Tsugita et al. patent) However,
this is not accurate, and depending upon the type of stent, not
only will it not trap such plaque, but plaque can reform through
the interstices of the mesh whereupon the vessel can again become
fully or partially occluded.
[0024] These shortcomings are present whether the stent is
mechanically expandable or self expanding. Relative to mechanically
expandable stents, they are delivered with a stent catheter. See
U.S. Pat. Nos. 5,507,768; 5,158,548 and 5,242,399 to Lau et al.
incorporated herein by reference. The catheter has an inflatable
balloon at or near the distal end on which the stent is mounted. An
inflation lumen runs the length of the catheter to the balloon.
Generally, the stent is a tubular mesh sleeve. See U.S. Pat. No.
4,733,665 to Palmaz incorporated herein by reference. A
self-expanding stent is typically made of Nitinol. It is compressed
within a catheter until deployment. It is pushed from the catheter
to deploy it. Both types of stents tend to create embolic
particles. Also, both allow stenotic material to build up through
the interstices of the wire mesh that could again occlude the
artery.
[0025] Permanent filters for the vena cava are well-established
clinical devices. These open filters capture large emboli passing
from a surgical site to the lungs. U.S. Pat. No. 3,952,747 to
Kimmell, Jr. et al. discloses the Kimray-Greenfield filter. It is a
permanent filter typically placed in the vena cava and consists of
a plurality of convergent legs in a generally conical array Each
leg has a hook at its end to impale the interior wall of the vena
cava. U.S. Pat. Nos. that are joined at their convergent ends to an
apical hub. U.S. Pat. Nos. 4,425,908 to Simon; 4,688,553 to Metals;
and 4,727,873 to Mobin-Uddin are also illustrative of such
devices.
[0026] U.S. Pat. Nos. 5,669,933 and 5,836,968 to Simon et al. are
illustrative of removable blood clot filters suitable for the
venous system, specifically the vena cava.
[0027] However, the presently available capture devices all suffer
from the limitation that they are not easily manipulated in the
patient's body. They usually include tube-like sheathing material
which extends all along the length of the guide wire used to insert
the capture device into the vessel, generally extending from the
entry site into the body, also known as an access port or access
opening to the operative site, which sheathing operates to contain
the capture device until its desired deployment in the vessel
beyond the operative site. Such sheathing material operates to
reduce torquability of the guide wire used to insert the capture
device and operates to significantly reduce the flexibility of wire
within the circulatory or other system as noted above. Removal
without causing excessive movement of the deployed filter is also a
problem. As the sheath is pulled from the access port during
removal, the surgeon must continually reposition his hand to hold
the wire used to insert the capture device, that is, as the sheath
is pulled through the access port, the surgeon must release the
wire and then re-grasp further down from the access port. As the
surgeon's hand grasps the wire further from the access port, the
more difficult it becomes to steady the guide wire as the sheath is
withdrawn. As such, the capture device may move back and forth, and
as it is generally at this point in its expanded state, the
constant rubbing of the wall of the blood or other vessel or canal
by the capturing device may irritate or injure the wall of the
blood or other vessel or canal.
[0028] Another complication is that several capture devices include
bulky or complex deployment mechanisms, and further, when deployed,
fail to fully seal around the interior of the vessel or other wall
or fail to prevent unwanted release of captured particles,
fragments, objects, emboli, etc., whereupon such particles,
fragments, objects, emboli, etc. can undesirably escape and travel
beyond the capture device.
[0029] Thus, there is a need in the art for a capture device and
methods of constructing and using such device, which is easily
threaded through the vessels or canals of humans and/or animals to
reach an operative site, which exhibits excellent torquability,
flexibility and maneuverability, which is easily removable along
with its captured objects once the medical procedure has been
completed without injuring or irritating the wall of the vessel or
canal, and which forms a seal with the wall of the vessel or canal
or otherwise prevents the undesirable escape of particles,
fragments, objects, emboli, etc. beyond the capture device during
surgery. There also is a need in the art for a system of
associating surgical tools with such a capture device to provide
protection downstream of an operative site for the capture of
objects dislodged and/or freed during the medical procedure.
SUMMARY OF THE INVENTION
[0030] The various embodiments and examples of the present
invention as presented herein are understood to be illustrative of
the present invention and not restrictive thereof and are
non-limiting with respect to the scope of the invention.
[0031] According to one non-limiting embodiment of the present
invention, a continuous pour concrete slip dowel is disclosed
configured for use across a joint between adjacent concrete slabs.
The continuous pour concrete slip dowel of the invention includes a
slip sleeve configured to be positioned within a first concrete
slab, and a main dowel rod having i) a first rod end portion
configured to be received within the slip sleeve, ii) a second
opposed rod end configured to be received within a second concrete
slab which is adjacent the first slab and spaced from the first
slab by a intervening joint, and iii) an intermediate coupling rod
portion connecting the first rod end with the second rod end,
wherein the coupling rod portion defines an offset therein whereby
the coupling rod portion is configured to extend around the
joint.
[0032] These and other advantages of the present invention will be
clarified in the description of the preferred embodiments taken
together with the attached figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a schematic perspective view of a concrete slip
dowel in position across a frame member with an expansion joint
forming member in accordance with one non-limiting embodiment of
the present invention;
[0034] FIG. 2 is a schematic perspective view of the concrete slip
dowel of FIG. 1;
[0035] FIG. 3 is a schematic cross sectional view of the concrete
slip dowel of FIG. 1;
[0036] FIG. 4 is a schematic cross sectional view of the concrete
slip dowel of FIG. 1 following a continuous pour of adjacent slabs
in accordance with the present invention;
[0037] FIG. 5 is a schematic cross sectional view of the concrete
slip dowel of FIG. 1 following a continuous pour of adjacent slabs
in accordance with the present invention;
[0038] FIG. 6 is a schematic cross sectional view of the concrete
slip dowel of a second embodiment of the present invention
following a continuous pour of adjacent slabs in accordance with
the present invention;
[0039] FIG. 7 is a schematic perspective view of the concrete slip
dowel of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] In summary, the present invention relates to a continuous
pour concrete slip dowel 10 which is disclosed configured for use
across a joint, such as an expansion joint having an expansion
member 16 between adjacent concrete slabs 18 and 20. The
construction of the expansion member is known in the art, but
generally is formed of a rubber or other elastomeric material to
accommodate slab expansion. The continuous pour concrete slip dowel
10 of the invention includes a slip sleeve 12 configured to be
positioned within a first concrete slab 18, and a main dowel rod 10
having i) a first rod end portion configured to be received within
the slip sleeve 12, ii) a second opposed rod end configured to be
received within a second concrete slab 20 which is adjacent the
first slab 18 and spaced from the first slab 18 by a intervening
joint that may include an expansion member 16 or the like, and iii)
an intermediate coupling rod portion connecting the first rod end
with the second rod end, wherein the coupling rod portion defines
an offset, such as through a U-Shaped configuration, therein
whereby the coupling rod portion is configured to extend around the
joint and around expansion member 16, if any, via extension into
the stone base. As the rod 10 makes up the main component of the
entire slip dowel arrangement, the term rod and dowel will be used
effectively interchangeably throughout this application. The dowel
10 assembly is inclusive of the slip sleeve 12.
[0041] The dowel rod 10 can be formed of any suitable material such
as from a rebar rod that is bent into the U shape as shown,
generally consisting of four ninety degree bends. The U-Shape as
shown provides several advantages for manufacturing and for
operation. First the U-shape allows for a sufficiently large radius
in the bends, such as about 1 inch diameter to the inner surface of
the rod in the bent portion, that conventional bending table,
bending rolls, or bending presses can be used on a conventional
rebar member, from about 1/4 inch to 1 inch diameter rebar, to form
the rod 10, without further heat treatment of the bent rod 10.
Obviously, the rod 10 can be made in other methods, such as casting
the rod 10 in a desired shape, or by hot working a bar or other
known methods; however cold working a rebar member on conventional
bending equipment is believed to provide certain cost advantages to
the present invention.
[0042] A further advantage of the general U-shape as shown is the
minimized contact with the frame member 14 and the expansion member
16. The minimal contact with these components allows the frame
member 14 to be more easily removed after the pour.
[0043] As described above the rod 10 is easily formed by bending or
cold working a rebar member of the appropriate length. It can be
formed as follows. A 1/2 inch diameter steel rebar member of the
desired length is inserted into a mechanical table bender with
about 9-12 inches of the rebar member that will form one end of the
rod 10 extending beyond a first bending pin, which may be a two
inch diameter pin. The rebar member is bent around the first pin to
about ninety degrees, thus forming one end of the rod 12 and the
first bend of the U shaped intermediate coupling rod portion. A
second pin, such as a two inch diameter pin, is provided on the
table and the rebar member is bent around the second pin for 180
degrees (or two 90 degree bends) to form the bottom of the U shaped
intermediate coupling rod. A third pin of the same diameter as the
first pin is provided on the table and the rebar member is bent
around the third pin to form the final upper bend of the U shaped
intermediate coupling rod with about 9-12 inches beyond the bend to
form the opposed end of the rod.
[0044] A two inch diameter pin for forming the inside of the U
shaped intermediate coupling rod allows the rod 10 to easily
accommodate a 2.times.4 wooden frame member 14 and expansion member
16 as it is well known that 2.times.4 wooden members are, in
actuality, less than 2 inches thick. The position of the second pin
is such that the height (vertical distance) of the rod 12 from the
lower end of the U shaped intermediate coupling rod to the upper
side of the end of the rod is about 4 inches to about 6 inches.
[0045] Each end of the rod will extend approximately 9 inch to 12
inches and the ends will preferably be co-axial and about the same
length. The co-axial arrangement of the ends of the rod 10 allows
the ends to be placed in the middle of the respective slabs 18 and
20. An overall height of the rod 10 of 4-6 inches allows the rod 10
to be used with most conventional concrete slab thicknesses. The
ends of the rod 10 should be extending substantially in the middle
of the slab 18 and 20 and perpendicular to the joint.
[0046] In operation the slip dowel 10 of the present invention
operates as follows. The dowel 10 is appropriate for use whenever
there is a joint between adjacent slabs 18 and 20 to be poured. The
concrete contractor will place a plurality of the slip dowels along
the line where the joint is to be formed, with the dowels 10 lying
on their sides in the stone base 22. The slip dowels 10 will be
aligned with their ends extending parallel to the ends of adjacent
slip dowels 10 and perpendicular to the joint. The slip sleeves 12
are loosely on at least one end of each slip dowel 10 rod.
[0047] The frame member 14 with expansion member 16 is placed in
position to complete the form. The remaining portions of the frame
are not shown but their construction is well known in the art. The
frame member 14 and expansion member 16 are placed to effectively
extend across the base of the U shaped intermediate coupling rod of
each rod 10. Each rod 10 is then pivoted up about the base of the U
shaped intermediate coupling rod to position the frame member 14
and expansion member 16 within the U shaped intermediate coupling
rod as shown in the figures, wherein the ends are positioned at a
height roughly 1/2 of the height of the associated slab 18 or 20 to
be poured. A pin can be used to secure the dowel rod 10 in the
desired position, with the pin driven into the ground and further
supporting the frame member 14, or driven into the frame member 14.
Alternatively the rods 10 can be supported via a concrete chair,
which is a small generally plastic support member resting on the
bed 22 that will be encased in the respective slab 18 or 20. At
this point each of the dowels 10 should be in a final position with
their ends parallel to each other and perpendicular to the joint
and about mid-height of the respective slabs 18 or 20. It should be
apparent that the same size dowel can be used for a range of
concrete thicknesses as the rotation placement step can adjust the
height throughout an entire range of heights up to the full height
of the individual dowel rods 10.
[0048] The next step is to pour the first slab 18 to the expansion
member 16 and to continue to pour the adjacent slab 20 in a single
continuous pour leaving the frame member 14 in position. The frame
member 14 can be removed after the concrete slabs 18 and 20 have
begun to firm up or set and the frame member 14 back filled and
finished in conventional concrete working fashion. The dowel rods
10 will be encased and secured to one slab 20 and allowed to move
relative to the other slab due to the sleeve 12.
[0049] It should be noted that the leg of the U shaped intermediate
coupling rod that is on the side of the sleeve 12 in slab 18 will
not be sufficiently secured to the slab 18 to prevent relative
motion due to expansion and relative lateral motion of slab 20 to
which the rod 10 is secured. This is mainly because the leg of the
U shaped intermediate coupling rod is effectively at the edge of
the slab 18 and the expansion member 16, by design, accommodates
the associated lateral motion. The U shape is also believed to
assist in the relative lateral motion. These factors allow the
sleeve 12 to be formed as shown in FIGS. 1-5, which is a simple
plastic tubular configuration that is currently commercially
available.
[0050] An alternative sleeve 12 design is shown in FIGS. 6-7, which
is designed to assure that the rod 10 can slide in and out of the
sleeve 12. In this modification the end of the sleeve is enlarged
to accommodate portions of the U shaped intermediate coupling rod,
and will prevent concrete forming slab 18 from attaching to any
portion of the rod. The slip dowel 10 of FIGS. 6-7 operates in the
same manner as the dowel of FIGS. 1-5, other than the construction
of the "wide mouth" sleeve 12. The modified sleeve of FIGS. 5-6
could be formed as a one piece molded structure or, alternatively,
as a two piece construction. The two piece modified "wide mouth"
sleeve 12 construction allows a conventional sleeve 12 to be used
with a second add on member forming the "wide mouth" end that
receives the U shaped intermediate coupling rod, with the add on
portion snapped, glued or otherwise affixed to the first sleeve
portion.
[0051] A further addition is that the ends of the rod need not be
parallel to each other. The end of the rod opposite from the sleeve
could be a zig-zag pattern or the like to facilitate bonding to the
concrete slab 20, if desired. Such a non-linear pattern should be
minimal and generally aligned with the axis of the other end to
maintain the structure in the middle of the slab 20. This
alternative is only identified to show the range of the present
invention, but is not generally believed to be worth the additional
fabrication costs. The design as shown in FIGS. 1-5 represents the
most cost effective, simple solution of the present invention.
[0052] Whereas particular embodiments of the invention have been
described above for purposes of illustration, it will be evident to
those skilled in the art that numerous variations of the details of
the present invention may be made without departing from the spirit
and scope of the present invention.
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