U.S. patent application number 16/738310 was filed with the patent office on 2020-05-14 for access device.
The applicant listed for this patent is ASSPV, LLC. Invention is credited to Janelle Anderson, William J. McCreight, Robert Rabiner, Michael Tal, Benjamin K. Yaffe.
Application Number | 20200147350 16/738310 |
Document ID | / |
Family ID | 39776363 |
Filed Date | 2020-05-14 |
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United States Patent
Application |
20200147350 |
Kind Code |
A1 |
Tal; Michael ; et
al. |
May 14, 2020 |
ACCESS DEVICE
Abstract
An access device places a medical article within a body space of
a patient. The device has a needle that includes an elongated body
and a needle hub. The device further includes a dilator disposed on
and slideable along the elongated body of the needle and a medical
article. The medical article is disposed on and slideable along the
dilator. A track extends in a proximal direction from the dilator.
The needle hub slides along at least a portion of the track between
a first position and a second position. The device further includes
a locking mechanism operably disposed between the track and the
needle hub so as to inhibit further axial movement of the needle in
the proximal direction when the needle hub is in the second
position.
Inventors: |
Tal; Michael; (Woodbridge,
CT) ; Anderson; Janelle; (New York, NY) ;
Yaffe; Benjamin K.; (San Francisco, CA) ; McCreight;
William J.; (Harleysville, PA) ; Rabiner; Robert;
(Tiverton, RI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASSPV, LLC |
San Diego |
CA |
US |
|
|
Family ID: |
39776363 |
Appl. No.: |
16/738310 |
Filed: |
January 9, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16246489 |
Jan 12, 2019 |
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16738310 |
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15703026 |
Sep 13, 2017 |
10441752 |
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16246489 |
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14543576 |
Nov 17, 2014 |
9764117 |
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15703026 |
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13185358 |
Jul 18, 2011 |
8900192 |
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14543576 |
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12106196 |
Apr 18, 2008 |
8105286 |
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13185358 |
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61036900 |
Mar 14, 2008 |
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60948136 |
Jul 5, 2007 |
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60912645 |
Apr 18, 2007 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 25/0606 20130101;
A61M 2005/1585 20130101; A61B 17/3415 20130101; A61B 2017/347
20130101; A61M 25/0612 20130101; A61M 2025/09125 20130101 |
International
Class: |
A61M 25/06 20060101
A61M025/06; A61B 17/34 20060101 A61B017/34 |
Claims
1. An insertion tool for inserting a catheter into a body of a
patient, comprising: (a) a hollow needle comprising a needle body
comprising a sharp distal tip, the needle body further comprising a
proximal end that is supported by a needle hub, the sharp distal
tip forming an opening and the needle body further comprising a
side wall defining at least one side opening therein; and (b) an
insertion assembly, comprising: (i) a catheter comprising a
catheter tube and a catheter hub at a proximal end thereof, the
catheter tube configured to be coaxially disposed over at least a
portion of the needle with the catheter hub being disposed distal
the needle hub; and (ii) a locking mechanism configured to allow
slideable extension of the needle within the insertion assembly,
wherein, when the needle is withdrawn through a portion of the
insertion assembly, the locking mechanism engages so as to prevent
further travel of the needle with respect to the locking mechanism
to isolate the sharp distal tip of the needle body and prevent
inadvertent needle sticks.
2. The insertion tool of claim 1: wherein the locking mechanism
comprises a binding element; wherein the binding element comprises
an unlocked position configured to allow translation of the needle
with respect to the insertion assembly along a longitudinal axis of
the needle; and wherein the binding element comprises a locked
position restraining motion of the needle with respect to the
insertion assembly upon a specified amount of withdrawal of the
needle into the insertion assembly.
3. The insertion tool of claim 2, wherein the binding element acts
to bind the needle in place to prevent further travel of the needle
with respect to the locking mechanism.
4. The insertion tool of claim 1, wherein at least a portion of the
insertion assembly encloses the sharp distal tip of the needle body
upon engagement of the locking mechanism with the needle.
5. The insertion tool of claim 1, wherein the insertion assembly
further comprises: a base configured to be releasably engaged to
the catheter hub, wherein, upon engagement of the locking mechanism
with the needle, the catheter hub may be disengaged from the base
so as to separate the catheter from the insertion assembly and the
needle, the sharp distal tip of the needle body remaining isolated
within the insertion assembly.
6. (canceled)
7. The insertion tool of claim 1, further comprising: a guide wire
disposed within the hollow needle and comprising a proximal end
disposed at or near the needle hub, wherein a distal end of the
guide wire is configured to be advanced distally within the hollow
needle such that the distal end extends out of the sharp distal tip
of the needle body.
8. (canceled)
9. The insertion tool of claim 1: wherein the catheter hub is
releasably secured to the insertion assembly; and wherein the
catheter hub is configured to be detached to separate the catheter
from the insertion assembly and the needle bound thereto.
10. A method for inserting a catheter into a body of a patient,
comprising: inserting a sharp distal tip of a hollow needle into a
lumen of a body of a patient, the sharp distal tip forming an
opening and the needle further comprising a side wall defining at
least one side opening therein, at least a portion of the needle
being coaxially disposed within a catheter of an insertion
assembly, the catheter comprising a catheter tube and a catheter
hub at a proximal end thereof, the needle supported by a needle hub
disposed proximal the catheter hub, the insertion assembly further
comprising a locking mechanism configured to allow slideable
extension of the needle within the insertion assembly; advancing
the catheter distally over the needle and into the lumen so that
the sharp distal tip of the needle is proximally withdrawn into the
insertion assembly; and engaging the locking mechanism of the
insertion assembly so as to prevent further travel of the needle
with respect to the locking mechanism, thereby isolating the sharp
distal tip of the needle to prevent inadvertent needle sticks.
11. The method of claim 10: wherein the locking mechanism comprises
a binding element; wherein engaging the locking mechanism comprises
engaging the binding element to bind the needle in place to prevent
further travel of the needle with respect to the locking mechanism;
wherein the binding element comprises an unlocked position
configured to allow translation of the needle with respect to the
insertion assembly along a longitudinal axis of the needle and a
locked position configured to constrain motion of the needle with
respect to the insertion assembly; and wherein, upon a specified
amount of withdrawal of the needle into the insertion assembly, the
binding element engages into the locked position.
12-13. (canceled)
14. The method of claim 10, further comprising: allowing flashback
of blood through the side opening upon insertion of the needle into
the lumen.
15. The method of claim 10, further comprising: advancing a distal
end of a guide wire distally within the hollow needle such that the
distal end extends out of the sharp distal tip of the needle.
16. The method of claim 15, wherein the guide wire further
comprises a proximal end disposed at or near the needle hub.
17. (canceled)
18. The method of claim 10, wherein the catheter hub is releasably
secured to the insertion assembly, the method further comprising:
detaching the catheter hub from the insertion assembly to separate
the catheter from the insertion assembly and the needle bound
thereto.
19. The insertion tool of claim 1, wherein the side opening is
adapted to permit the flow of blood therethrough and out of the
needle body.
20. The insertion tool of claim 1, wherein the catheter further
comprises at least one wing for moving the catheter.
21. The insertion tool of claim 20, wherein the at least one wing
is coupled to the catheter hub and is removable from at least a
portion of the catheter hub.
22. The insertion tool of claim 1, wherein the catheter hub
comprises a plurality of ridges.
23. The insertion tool of claim 1, wherein the locking mechanism
comprises at least one finger element.
24. The insertion tool of claim 7, wherein a portion of the guide
wire near the distal end of the guide wire comprises a reduced
diameter in comparison to at least one other section of the guide
wire.
25. The method of claim 10, wherein the catheter further comprises
at least one wing for moving the catheter.
26. The method of claim 25, wherein the at least one wing is
coupled to the catheter hub.
27. The method of claim 26, further comprising removing the at
least one wing from at least a portion of the catheter hub.
28. The method of claim 10, wherein the catheter hub comprises a
plurality of ridges.
29. The method of claim 10, wherein the locking mechanism comprises
at least one finger element.
30. The method of claim 15, wherein a portion of the guide wire
near the distal end of the guide wire comprises a reduced diameter
in comparison to at least one other section of the guide wire.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/703,026 filed on Sep. 13, 2017, which is a
continuation of U.S. patent application Ser. No. 14/543,576 filed
on Nov. 17, 2014, which issued as U.S. Pat. No. 9,764,117 on Sep.
19, 2017, which is a continuation of U.S. patent application Ser.
No. 13/185,358 filed on Jul. 18, 2011, which issued as U.S. Pat.
No. 8,900,192 on Dec. 2, 2014, which is a division of U.S. patent
application Ser. No. 12/106,196 filed on Apr. 18, 2008, which
issued as U.S. Pat. No. 8,105,286 on Jan. 31, 2012, which claims
priority to, and the benefit of, U.S. Provisional Patent
Application Ser. No. 61/036,900 filed on Mar. 14, 2008, U.S.
Provisional Patent Application Ser. No. 60/948,136 filed on Jul. 5,
2007, and U.S. Provisional Patent Application Ser. No. 60/912,645
filed on Apr. 18, 2007, all of which are hereby expressly
incorporated by reference in their entireties.
BACKGROUND
Field of the Invention
[0002] This invention is generally directed to access devices for
introducing and/or delivering a medical article (such as, for
example, a catheter, cannula, sheath, etc.) into a body space, such
as, for example, an artery, vein, vessel, body cavity, or drainage
site.
Description of the Related Art
[0003] A preferred non-surgical method for inserting a catheter or
vascular sheath into a blood vessel involves the use of the
Seldinger or a modified Seldinger technique, which includes an
access needle that is inserted into a patient's blood vessel. A
guidewire is inserted through the needle and into the vessel. The
needle is removed, and a dilator and sheath in combination or
separately are then inserted over the guidewire. The dilator and
sheath, together or separately, are then inserted a short distance
through the tissue into the vessel, after which the dilator and
guidewire are removed and discarded. A catheter or other medical
article may then be inserted through the sheath into the vessel to
a desired location, or the sheath may simply be left in the
vessel.
[0004] A number of vascular access devices are known. U.S. Pat.
Nos. 4,241,019, 4,289,450, 4,756,230, 4,978,334, 5,124,544,
5,424,410, 5,312,355, 5,212,052, 5,558,132, 5,885,217, 6,120,460,
6,179,823, 6,210,332, 6,726,659 and 7,025,746 disclose examples of
such devices. None of these devices, however, has the ease and
safety of use that physicians and other healthcare providers would
prefer. Thus, there exists a need for an easier-to-use and safer
vascular access device, especially one that would clearly and
promptly indicate when a blood vessel has been punctured and one
that would reduce accidental needle sticks and other attendant
risks of over-wire vascular access.
SUMMARY
[0005] Embodiments of the present invention involve several
features for an access device useful for the delivery of a catheter
or sheath into a space within a patient's body, such as, for
example, a blood vessel or drainage site. Without limiting the
scope of this invention, its more prominent features will be
discussed briefly. After considering this discussion, and
particularly after reading the Detailed Description of the
Preferred Embodiments section below in combination with this
section, one will understand how the features and aspects of these
embodiments provide several advantages over prior access
devices.
[0006] One aspect of the present invention is an access device for
placing a medical article within a body space. The device includes
a needle that has an elongated needle body with a distal end and a
hub from which the needle body extends. The device further includes
a dilator disposed on the needle body. The needle and the dilator
are moveable relative to each other from a first position, wherein
the distal end of the needle lies distal of the dilator, and a
second position, wherein the distal end of the needle lies within
the dilator. The dilator includes a dilator hub and an elongated
dilator shaft that extends from the dilator hub. The device further
includes a locking mechanism that operates between the needle and
the dilator to inhibit movement of the needle relative to the
dilator when in the second position. The locking mechanism is
configured to allow movement of the needle from the first position
toward the second position without engagement by the locking
mechanism so as to lessen resistance to the movement.
[0007] Another aspect of the invention is an access device for
placing a medical article within a body space. The device includes
a needle that has a needle body with a longitudinal axis, a distal
tip, and a needle hub from which the needle body extends. The
device further includes a dilator that has a dilator shaft and a
dilator hub. The dilator shaft is disposed on and slideable along
the needle body with the dilator hub being disposed distal of the
needle hub. The device further includes a medical article that has
a tubular section and a hub. The tubular section is disposed on and
slideable along the dilator with the hub being disposed distal of
the dilator hub. The device includes a track that extends from the
dilator hub in a proximal direction and a locking mechanism
operably disposed between the track and the needle hub so as to
selectively inhibit proximal movement of the needle relative to the
dilator.
[0008] Yet another aspect of the invention is an access device for
placing a medical article within a body space. The device includes
a needle that has a distal end and a first fenestration. The device
further includes a dilator disposed on and slideable along the
needle and has a second fenestration. One of the first and second
fenestrations has a greater dimension in at least one direction
than the other one of the first and second fenestrations in said
direction. The device further includes a medical article being
coaxially disposed and longitudinally movable over the dilator.
[0009] Yet another aspect is an access device for placing a medical
article within a body space. The device includes a needle having a
distal end and at least one fenestration. The device further
includes a dilator that has a shaft disposed on at least a portion
of the needle. The device further includes a medical article
disposed on at least a portion of the dilator and at least one
elongated channel disposed between the needle and an exterior
surface of the medical article that extends along at least a
substantial portion of the length of the dilator shaft. The channel
communicates with the fenestration in the needle and has a span
angle of less than 360 degrees about a longitudinal axis of the
dilator.
[0010] Another aspect involves a pre-assembled access device for
placing a medical article within a body space. The device includes
a needle having a distal end with at least one fenestration and a
dilator including a shaft coaxially disposed about at least a
portion of the needle. The device further includes a medical
article coaxially disposed about at least a portion of the dilator
and at least one elongated channel formed between the needle and
the exterior surface of the medical article. The channel extends
along at least a substantial portion of the length of the dilator
shaft. The channel communicates with the fenestration in the
needle. The channel is defined at least in part by a groove formed
on an inner surface of the medical device, on an outer surface of
the dilator, on an inner surface of the dilator, or a combination
of such grooves. In some modes, the groove extends only partially
around a longitudinal axis of the needle, and in other modes the
groove spirals along the axis.
[0011] Still another aspect is a method of removing a needle and
dilator assembly from a patient where the dilator is coaxially
disposed about at least a portion of the needle. The method
includes moving a needle relative to a dilator from a first
position to a second position. A distal end of the needle lies
distal of the dilator in the first position. The distal end of the
needle lies within the dilator in the second position. The method
further comprises inhibiting further movement of the needle
relative to the dilator once the needle is in the second
position.
[0012] A further aspect involves an access device for placing a
medical article within a body space. The access device comprises a
needle having a distal end and a longitudinal axis, and a dilator
disposed on at least a portion of the needle and having an outer
surface. A medical article is disposed on at least a portion of the
dilator and has an inner surface. At least a portion of the inner
surface of the medical article or a portion of the outer surface of
the dilator has a dissimilar shape to that of an adjacent portion
of the outer surface of the dilator or inner surface of the medical
article (respectively) so as to form a gap therebetween, which
extends along the longitudinal axis.
[0013] A releasable interlock can be provided in some embodiments
to inhibit relative rotational movement between the needle and the
dilator, at least when the needle is inserted into a patient. By
inhibiting such relative rotational movement, communicating
fenestrations in the needle and the dilator can be held in
alignment to provide a simplified channel through which the blood
or fluid may flow. Thus, when the needle enters a blood vessel or
drainage site in the patient, blood or other body fluid quickly
flows into the channel. The resulting blood or fluid flash is
visible through the sheath (or catheter) to indicate that the
needle tip has entered the vessel or drainage site.
[0014] For example, but without limitation, the dilator can
comprise, in some embodiments, a dilator hub and dilator having one
or more side fenestrations. The dilator hub may have a luer
connection and a releasable locking mechanism. The releasable
locking mechanism can be configured to releasably engage and secure
the dilator to another part, such as the needle hub. When the
needle hub and the dilator hub are releasably locked to prevent
rotation therebetween, at least a portion of one or more of the
side fenestrations in the dilator are aligned with at least a
portion of one or more side fenestrations in the needle. The
locking mechanism can also be configured to inhibit unintentional
relative axial movement between the needle and the dilator.
[0015] The medical article preferably, but not necessarily,
includes a sheath and sheath hub. The sheath may be made partially
or completely from a clear, translucent, semi-opaque, or
transparent material. Such transparent, translucent, semi-opaque
and clear materials allow a clinician the ability to see when blood
or other body fluids flows into the needle, through the needle
fenestration(s), through the side dilator fenestration(s), and into
the viewing space between the dilator and sheath. The sheath may
also have radiopaque stripes so disposed as not to obscure the
viewing space.
[0016] These and other aspects of the present invention will become
readily apparent to those skilled in the art from the following
detailed description of the preferred embodiments, which refers to
the attached figures. The invention is not limited, however, to the
particular embodiments that are disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other features, aspects, and advantages of the
access device disclosed herein are described below with reference
to the drawings of preferred embodiments, which are intended to
illustrate and not to limit the invention. Additionally, from
figure to figure, the same reference numerals have been used to
designate the same components of an illustrated embodiment. Like
components between the illustrated embodiments are similarly noted
as the same reference numbers with a letter suffix to indicate
another embodiment. The following is a brief description of each of
the drawings.
[0018] FIG. 1A is a perspective view of a preferred embodiment of
an access device configured in accordance with the present
invention and shows a pre-loaded guidewire section coaxially
aligned with a needle, a dilator, and a medical article.
[0019] FIG. 1B is a plan view of the embodiment depicted in FIG.
1A.
[0020] FIG. 2A is a plan view of the needle from FIG. 1A and shows
a fenestration near a distal end.
[0021] FIG. 2B is a side view of the needle from FIG. 1A and shows
a fin near a proximal end.
[0022] FIG. 2C is a cross-sectional view taken along the lines
2C-2C in FIG. 2A.
[0023] FIG. 2D is an enlarged plan view of a portion of the needle
of FIG. 2A and shows the fenestration.
[0024] FIG. 2E is an enlarged plan view of the needle hub of the
needle of FIG. 2A.
[0025] FIG. 2F is an enlarged side view of the needle hub of the
needle of FIG. 2A.
[0026] FIG. 2G is an enlarged proximal end view of the needle hub
of the needle of FIG. 2A.
[0027] FIG. 3A is a plan view of the dilator from FIG. 1A and shows
a fenestration near a distal end. FIG. 3A also shows longitudinally
arranged grooves in the luer surface for venting air from between
the dilator and sheath.
[0028] FIG. 3B is a cross-sectional view taken along the lines
3B-3B in FIG. 3A.
[0029] FIG. 3C is an enlarged plan view of a portion of the dilator
from FIG. 3A and shows the fenestration and longitudinal
channel.
[0030] FIG. 3D is an enlarged end view of the dilator hub from FIG.
3A.
[0031] FIG. 3E is a perspective view of another embodiment of the
dilator hub that includes a locking spin nut configured to secure
to a sheath that has a corresponding screw thread.
[0032] FIG. 3F is a cross-sectional view taken along the lines
3F-3F in FIG. 3A and shows the grooves equally spaced about the
circumference of the luer surface.
[0033] FIG. 4A is a plan view of the sheath from FIG. 1A and shows
a sheath hub connected to a proximal end of a sheath.
[0034] FIG. 4B is a cross-sectional view taken along the lines
4B-4B in FIG. 4A.
[0035] FIG. 4C is an enlarged end view of the sheath from FIG.
4A.
[0036] FIG. 4D is an enlarged perspective view of a proximal
portion of the sheath from FIG. 4A.
[0037] FIG. 5A is a perspective view of the guidewire section from
FIG. 1A and shows a guidewire hub connected to a proximal end of a
guidewire.
[0038] FIG. 5B is a plan view of the guidewire section of the
embodiment depicted in FIG. 5A.
[0039] FIG. 6A is a perspective view of a track from FIG. 1A.
[0040] FIG. 6B is a plan view of the track in FIG. 6A and shows a
locking mechanism for locking the needle relative to the
dilator.
[0041] FIG. 6C is a side view of the track in FIG. 6B.
[0042] FIG. 6D an enlarged view of the locking mechanism from FIG.
6B.
[0043] FIG. 6E is an enlarged view of another locking mechanism
that locks the guidewire section in a pre-loaded state.
[0044] FIG. 7A is a plan view of the access device from FIG. 1A and
shows the locking mechanism from FIG. 6E with the guidewire section
locked to the track in the pre-loaded state.
[0045] FIG. 7B is a side view of the access device and locking
mechanism from FIG. 7A.
[0046] FIG. 7C is a cross-sectional view through the access device
of FIG. 7A and shows the guidewire hub disposed between an element
and stop of the track.
[0047] FIG. 7D is an enlarged end view of the access device from
FIG. 7B and shows two arms extending from the track and around at
least a portion of the guidewire hub.
[0048] FIG. 8A is a plan view of the embodiment depicted in FIG. 1A
illustrating the insertion of the distal end of the access device
into a patient.
[0049] FIG. 8B is an enlarged view of the embodiment depicted in
FIG. 8A focusing on the area of the access device adjacent to the
patient.
[0050] FIG. 8C is an enlarged view of a portion of the embodiment
depicted in FIG. 8B and illustrates the needle opening or
fenestration aligned with the dilator opening or fenestration in
hidden lines.
[0051] FIG. 8D is an enlarged cross-sectional view of a portion of
the embodiment depicted in FIG. 8C and shows the needle opening or
fenestration aligned with the dilator opening or fenestration so as
to allow fluid to flow from inside the needle to a channel formed
between the sheath and dilator.
[0052] FIG. 8E is a graph showing the rate fluid is drawn up a
channel with a gap height width of 0.002 inches.
[0053] FIG. 8F is a graph showing the rate fluid is drawn up a
channel with a gap height width of 0.001 inches.
[0054] FIG. 8G is a graph showing the rate fluid is drawn up a
channel with a gap height width of 0.0005 inches.
[0055] FIG. 8H is an enlarged cross-sectional view of a portion of
the embodiment depicted in FIG. 8C taken through a region distal of
the channel in the dilator.
[0056] FIG. 8I is an enlarged view of the embodiment depicted in
FIG. 8A focusing on the area where the needle hub is locked to the
dilator hub when the needle hub is in the first position.
[0057] FIG. 8J is a cross-sectional view of the embodiment depicted
in FIG. 8I.
[0058] FIG. 9A is a side view of the embodiment depicted in FIG. 1A
illustrating the guidewire advanced from the needle tip in a distal
direction.
[0059] FIG. 9B is an enlarged view of the embodiment depicted in
FIG. 9A focusing on the area where the guidewire hub is locked to
the needle hub when the needle hub is in the first position.
[0060] FIG. 9C is a cross-sectional view of the embodiment depicted
in FIG. 9B.
[0061] FIG. 10A is a side view of the embodiment depicted in FIG.
1A illustrating the dilator and sheath being advanced distally
relative to the needle body from the position illustrated in FIG.
9A.
[0062] FIG. 10B is an enlarged rear view of the embodiment depicted
in FIG. 10A focusing on the area where the needle hub is locked to
the track when the needle hub is in the second position.
[0063] FIG. 11A is a side view of the embodiment depicted in FIG.
1A illustrating the removal of the guidewire, needle body, and
dilator from the sheath.
[0064] FIG. 11B is an enlarged view of the portion of the
embodiment illustrated in FIG. 11A showing the needle tip covered
by the dilator during removal of the guidewire, needle body, and
dilator from the sheath.
[0065] FIG. 12A is an enlarged plan view that illustrates another
embodiment of the aligned openings or fenestrations in the needle
and dilator.
[0066] FIG. 12B is an enlarged cross-sectional view along lines
13B-13B in FIG. 12A and shows the needle opening or fenestration
aligned with the dilator opening or fenestration so as to allow
fluid to flow from inside the needle to a channel formed between
the sheath and dilator.
[0067] FIG. 13A is an enlarged plan view that illustrates another
embodiment of the aligned openings or fenestrations in the needle
and dilator.
[0068] FIG. 13B is an enlarged cross-sectional view along lines
13B-13B in FIG. 13A and shows the needle opening or fenestration
aligned with the dilator opening or fenestration so as to allow
fluid to flow from inside the needle to a channel formed between
the sheath and dilator
[0069] FIG. 14A is an enlarged plan view that illustrates another
embodiment of the channel formed between the dilator and the
sheath.
[0070] FIG. 14B is a cross-sectional view along lines 14B-14B in
FIG. 14A and shows the thickness of the channel extending into the
sheath.
[0071] FIG. 15A is an enlarged plan view that illustrates another
embodiment of the channel formed between the dilator and the
sheath.
[0072] FIG. 15B is a cross-sectional view along lines 15B-15B in
FIG. 15A and shows the thickness of the channel extending into both
the dilator and the sheath.
[0073] FIG. 16A is an enlarged plan view that illustrates another
embodiment of the channel formed between the dilator and the
sheath.
[0074] FIG. 16B is a cross-sectional view along lines 16B-16B in
FIG. 15A and shows a plurality of equally spaced channels in the
form of splines extending into the dilator.
[0075] FIG. 17 is an enlarged cross-sectional view through another
embodiment of the access device and shows the channel formed
between a sheath and a dilator that have dissimilar shapes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0076] The present disclosure provides an access device for the
delivery of a medical article (e.g., catheter or sheath) to a blood
vessel or drainage site. FIG. 1A illustrates an access device 20
that is configured to be inserted into a blood vessel (e.g., a vein
or an artery) in accordance with a preferred embodiment of the
present invention. While the access device is described below in
this context (i.e., for vascular access), the access device also
can be used to access and place a medical article (e.g., catheter
or sheath) into other locations within a patient's body (e.g., a
drainage site) and for other purposes (e.g., for draining an
abscess).
[0077] The present embodiment of the access device is disclosed in
the context of placing an exemplary single-piece, tubular medical
article into a body space within a patient. Once placed, the
tubular article can then be used to receive other medical articles
(e.g., catheters, guidewires, etc.) to provide access into the body
space and/or be used to provide a passage way for introducing
fluids into the body space or removing (e.g., draining) fluids from
the body space. In the illustrated embodiment, the tubular medical
article is a sheath or catheter that is configured primarily to
provide a fluid passage into a vein. The principles of the present
invention, however, are not limited to the placement of single
piece sheaths or catheters, or to the subsequent insertion of a
medical article via the sheath or catheter. Instead, it will be
understood by one of skill in this art, in light of the present
disclosure, that the access device disclosed herein also can be
successfully utilized in connection with placing one or more other
types of medical articles, including other types of sheaths, fluid
drainage and delivery tubes, and single or multi-lumen catheters
directly in the patient or indirectly via another medical
article.
[0078] For example, but without limitation, the access device
disclosed herein can also be configured to directly or indirectly
place central venous catheters, peripherally inserted central
catheters, hemodialysis catheters, surgical drainage tubes,
tear-away sheaths, multi-piece sheaths, scopes, as well as
electrical conduit for wires or cables connected to external or
implanted electronic devices or sensors. As explained above, the
medical articles listed above may be directly placed in the patient
via the dilator, needle, and guidewire of the access device or
subsequently placed within the patient via a medical article that
was placed within the patient via the dilator, needle, and
guidewire of the access device.
[0079] Further, the embodiments disclosed herein are not limited to
co-axial insertion of a single medical article. For example, two
catheters may be inserted in the patient via an inserted sheath or
a second catheter may be inserted in the patient via an inserted
first catheter. Further, in addition to providing a conduit into
the vessel or other body space, the medical article inserted via
the dilator, needle, and guidewire can form a lumen that is in
addition to the lumen(s) of the subsequently inserted medical
article. One skilled in the art can also find additional
applications for the devices and systems disclosed herein. Thus,
the illustration and description of the access device in connection
with a sheath (e.g., for micro puncture applications) is merely
exemplary of one possible application of the access device.
[0080] FIGS. 1A and 1B illustrated a preferred embodiment of an
access device 20. The access device 20 comprises a needle 22, a
dilator 24, and a sheath 26. In the illustrated embodiment, the
access device also includes a guidewire section 28 and a track 30.
As best seen in FIG. 1B, the dilator 24 is preferably coaxially
mounted on the needle 22, and the sheath 26 is coaxially mounted on
the dilator 24. The telescoping nature of the access device's
components can also be accomplished by arranging the components
with their axes arranged substantially parallel rather than
coaxially (e.g., a monorail-type design).
[0081] Each of these components includes a luminal fitting at a
terminal end or transition (i.e., a hub) and elongated structure
that extends from the fitting. Thus, in the illustrated embodiment,
the needle 22 includes a needle body 32 that extends distally from
the needle hub 34, the dilator 24 includes a dilator shaft 36 that
extends distally from a dilator hub 38, and the sheath 26 includes
a sheath body 40 that extends distally from a sheath hub 42. The
guidewire section 28 comprises a guidewire 44 and preferably a
guidewire hub or cap 46. In the illustrated embodiment, the
guidewire hub 46 is disposed on the proximal end of the guidewire
44; however, in other applications, the hub 46 can be disposed at a
location between the ends of the guidewire 44.
[0082] FIGS. 2A-2G illustrate the needle body 32 and needle hub 34
of the needle 22, which are configured in accordance with a
preferred embodiment of the access device, in isolation from the
other components of the access device 20. As best seen in FIGS. 2A
and 2B, the needle hub 34 is disposed on a proximal end of the
needle body 32. The needle body 32 terminates at a distal end near
a distal portion 50 of the needle 22, and the needle hub 34 lies at
a proximal portion 52 of the needle 22.
[0083] The needle body 32 preferably has an elongated tubular shape
having a circular, constant-diameter inner bore and a circular,
constant-diameter exterior surface. In other embodiments, however,
the needle body 32 can have other bore and exterior shapes (such
as, for example, but without limitation, an oval cross-sectional
shape). The interior or exterior of the needle can also include
grooves or channels. The grooves or channels may guide fluids
within the needle bore either around or to certain structures of
the needle 22 or within the needle 22 (e.g., around the guidewire).
In some embodiments, the grooves or channels may assist in
maintaining a desired orientation of the needle 22 with respect to
the dilator.
[0084] The needle body 32 has a sufficiently long length to access
a targeted subcutaneous body space and has a sufficient gauge size
to withstand the insertion forces when accessing the body space
without causing undue trauma. For many applications, the needle
body can have a length between 3-20 cm, and more preferably between
3-10 cm. For example, to access a body space (e.g., a vessel) in
the thorax of an adult human, the needle body 32 preferably has a
length of 7 cm or greater, and more preferably has a length of 9 cm
or greater, and most preferably has a length of 9 to 10 cm. The
size of the needle preferably is 18 gauge or smaller, and more
preferably between 18-28 gauge, and most preferably between 18-26
gauge for micro-puncture applications (peripheral IVs). For
applications with a neonate, the length and gauge of the needle
body 32 should be significantly shorter and smaller, for example
preferably between 3-4 cm and between 26-28 gauge.
[0085] As best seen in FIGS. 2A and 2D, the needle body 32 includes
at least one fenestration or opening 56 near a distal end of the
needle body 32. The fenestration 56 extends through the wall of the
needle body 32 and can have a variety of shapes and orientations on
the needle body 32, as described in detail below. In addition, the
needle body 32 can have a bevel tip 54 disposed on the distal
portion 50.
[0086] As is illustrated in FIG. 2A, the fin 58 is preferably
disposed at a circumferential location around the needle hub 34
that is aligned with the circumferential locations of the bevel on
the needle tip and the opening or fenestration 56 in the needle.
That is, the fin 58 is indexed with the bevel and fenestration.
During use, the physician or healthcare provider can determine the
orientation of the beveled needle tip (and the fenestration 56) by
noting the orientation of the exposed fin 58 even though the bevel
is inside the vessel and the fenestration is covered by the sheath
and/or dilator. For example, in the illustrated embodiment, an
orientation of the fin 58 away from the patient coincides with a
bevel up orientation of the needle tip within the vessel. The
fenestration 56 is also on the same side as the fine 58, as seen in
FIG. 2C.
[0087] As shown most clearly in FIG. 2B, the illustrated embodiment
of the needle hub 34 has a finger-hold, tab or fin 58. The fin 58
provides a grasping region to manipulate the needle hub 34. For
example, a physician or healthcare provider can place an index
finger and thumb on the sides of the fin 58 to stabilize the needle
hub 34, relative to the dilator 24 and/or sheath 26. In the
illustrated embodiment, as the dilator/sheath slides distally over
the needle, the needle hub 34 slides relatively along the track 30
between a first position 121 and a second position 123. The fin 58
can be held when performing the insertion step (which will be
described below). In addition, the fin 58 can be used to stabilize
the needle hub 34 while rotating the dilator hub 38. Furthermore,
the fin 58 can be used by a physician or healthcare provider as an
aid to grasp the access device 20 when the needle hub 34 is
disposed at any position along the track 30.
[0088] FIG. 2D is an enlarged view of the side opening or
fenestration 56 in the needle body 32. The one or more fenestration
56 provides a path through the side of the needle body 32. The
fenestration 56 illustrated in FIG. 2D has an oblong shape. The
shape of the side opening 56, however, is not limited to the
illustrated embodiment and may be round, oblong, square, or another
shape.
[0089] With specific reference now to FIGS. 2E-2G, the needle hub
34 preferably includes locking structures at the proximal portion
and distal portion of the needle hub 34. These locking structures
may be a luer-thread-type or another type of connections.
[0090] The locking structure on the proximal portion 52 of the
needle hub 34 allows the physician or healthcare provider to secure
another medical article to the proximal end of the needle hub 34.
For example, the needle hub 34 in the illustrated embodiment
includes an annular flange or lip 63. The lip 63 is threaded to
allow the needle hub 34 to attach to other medical articles with a
corresponding luer-nut locking feature. Additionally, a physician
or healthcare provider may attach a syringe or monitoring equipment
to the locking structure on the proximal end to perform other
procedures as desired. The needle hub 34 can also include a septum
at its proximal end and/or a side port if these features are
desirably for a particular application.
[0091] The locking structure on the distal portion of the needle
hub 34 allows the physician or healthcare provider, for example, to
lock the needle hub 34 to the dilator hub 38 when the needle hub 34
is in the first position 121. In the illustrated embodiment, the
locking structure includes a latch element 66 on the needle hub 34.
The latch element 66 releasably locks the needle hub 34 to the
dilator hub 38. The locking structure allows the healthcare provide
to advance the needle into a patient while grasping the needle hub
34, the dilator hub 38 or both.
[0092] As explained below in greater detail, the guidewire 44 is
introduced through a hollow portion 62 of the needle hub 34,
through the needle body 32, and into a punctured vessel. The
guidewire 44 allows the healthcare provider to guide the dilator 24
and sheath 26 into the vessel.
[0093] The needle hub 34 may also comprise two tangs 68 that allow
the needle hub 34 to slide along the track 30 between a first
position 121 and a second position 123. While in the preferred
embodiment the two tangs 68 of the needle hub 34 are engaged with
the track 30 between the first position 121 and the second position
123, in other embodiments the needle hub 34 is only engaged with
the track 30 over a portion of the length of the track 30 between
the first position 121 and the second position 123. The sliding
interconnection between the track 30 and the needle hub 34 also can
be accomplished using other cooperating structures (e.g., a
corresponding pin and tail of dovetail connection).
[0094] FIG. 3A is a plan view of the dilator 24 of the embodiment
depicted in FIG. 1A. FIG. 3B is a cross-sectional view of the
dilator 24 of the embodiment depicted in FIG. 3A, taken along line
3B-3B. As shown in FIGS. 3A and 3B, the illustrated dilator 24
comprises a dilator shaft 36, a dilator hub 38, a distal region 70,
and a proximal region 72. In the illustrated embodiment, the
dilator shaft 36 includes a side openings or fenestrations 74;
however, in other embodiments, the dilator shaft 36 can include
fewer or greater numbers of fenestrations 74. For example, the
dilator shaft 36 may not include a fenestration 74 where a blood
flash chamber(s) is disposed within the dilator (as will be
described in more detail below).
[0095] The dilator hub 38 may comprise one or more vents. In the
illustrated embodiments, the vents in the dilator hub 38 are formed
by grooves 75. Additionally, the dilator shaft 36 may comprise one
or more longitudinal channels formed in the outer surface of the
dilator shaft 36. In the illustrated embodiment, the channel is an
open channel. The side walls of the open channel are formed by
ridges 76. In the illustrated embodiment, the ridges 76 define
generally smooth, arcuate exterior surfaces that interface with the
sheath 26; however, in other embodiments, the ridges can have other
shapes (e.g., can defined more pronounced apexes). Once assembled
within a sheath body 40, the open channel in the dilator shaft 36
is closed by the inside diameter of the sheath body 40.
[0096] FIG. 3C is an enlarged plan view of a portion of the
embodiment illustrated in FIG. 3A. As noted above, the illustrated
dilator shaft 36 comprises one or more side openings 74 and one or
more channels formed between ridges 76. The side opening or
fenestration 74 provides a fluid path through the side of the
dilator shaft 36. The shape of the side opening 74 is not limited
to the illustrated embodiment and may be round, oblong, square, or
have another shape. The opening or fenestration 74 illustrated in
FIG. 3C has an oblong shape.
[0097] In the illustrated embodiment, the opening 74 in the dilator
shaft 36 has an oblong shape with its major axis being non-parallel
relative to the major axis of the oblong opening 56 in the needle.
For example the needle opening 56 may extend in a longitudinal
direction and the dilator opening 74 may extend in a
circumferential direction or vice versa. In other words, the long
axis of the dilator opening 74 is disposed generally perpendicular
to the long axis of the needle opening 56. As explained in
connection with additional embodiments below, these openings 56, 76
can have other shapes, sizes and orientations that preferably
obtain a significant degree of overlap to account for manufacturing
tolerances and rotational misalignments. For this reason, it is
preferred that one of the fenestrations has a greater dimension in
at least one direction than the other one of the fenestrations in
the same direction. Accordingly, in the illustrated embodiment, the
needle fenestration 56 has a longer longitudinal dimension than the
longitudinal dimension of the dilator fenestration 74.
[0098] The channel formed between the ridges 76 extends in a
proximal direction from a point distal to the opening 74. The
ridges 76 in the illustrated embodiment are disposed along the
dilator shaft 36 and on opposite sides of the dilator shaft 36 so
as to balance the dilator shaft 36 within the sheath. In the
illustrated embodiment, the ridges 76 form two channels there
between. Balancing the dilator within the sheath allows the dilator
to apply equal pressure to the inside circumference of the
sheath.
[0099] The dilator hub 38 may include locking structures at the
proximal region 72 and the distal region of the dilator 24. Each
locking structure may be a luer type or other type of connection.
In the illustrated embodiment, the dilator hub 38 comprises a first
luer connection 78, a second luer connection 80, a lip 77, and a
base 79. The first luer connection 78 engages to the needle hub 34
on the needle 22 illustrated in FIG. 2E. The second luer connection
80 is disposed distal to the first luer connection 78. In some
embodiments, the second luer connection 80 (e.g., a male luer slip
connector) can be configured to engage to the sheath hub 42 (e.g.,
a female luer slip connector) on the sheath 26 illustrated in FIG.
1A. Additionally, the male-female lure slip connectors on these
components can be reversed.
[0100] FIG. 3D is an enlarged proximal end view of the dilator 24
of FIG. 3A. As shown most clearly in FIG. 3D, the dilator hub 38
comprises an opening 82 that releasably engages the latch element
66 on the needle hub 34 illustrated in FIG. 2E-2F to secure the
dilator hub 38 to the needle hub 34 when the needle hub 34 is in
the first position 121. Again, the male-female lure slip connectors
on the dilator hub and the needle hub 34 can also be reversed in
other embodiments.
[0101] The color of the dilator 24 may be selected to enhance the
contrast between the blood or other fluid and the dilator 24.
During blood flash, for example, blood is observed flowing between
the dilator 24 and the sheath to confirm proper placement of the
needle in a blood vessel. To increase the visibility of the fluid
as the fluid flows between the sheath and dilator 24, the sheath is
preferably manufactured from a clear or transparent material with
the dilator 24 having a color that contrasts with the color of the
fluid. For example, the dilator 24 may have a white color to
enhance its contrast with red blood. Other colors of dilator 24
could be employed depending on the color of the fluid and the
degree of contrast desired. Further, only a portion of the dilator
in the region of the blood flash can have the contrasting color
with the remainder having a different color. For embodiments that
have a channel formed between the needle and dilator 24, the
dilator 24 may be manufactured of a clear or transparent material
similar to the sheath to allow the physician to observe the blood
flash through both the sheath and dilator 24.
[0102] FIG. 3E is an enlarged perspective view of another
embodiment of a dilator hub 38A. The dilator hub 38A is similar to
the dilator hub 38 illustrated in FIG. 3A except that the dilator
hub 38A further includes a spin nut or collar 84. The proximal end
of the spin nut 84 rotates about an annular groove 73 in the
dilator hub 38 (see FIG. 3A). Once disposed within the annular
groove 73, the spin nut 84 is inhibited from moving in the distal
direction but is free to rotate about the dilator hub 38A. The spin
nut 84 can have an interengaging element that locks to a
corresponding interengaging element on the sheath 26. In the
illustrated embodiment, the spin nut 84 includes an internal thread
which engages with an external thread on the sheath hub 42 on the
sheath 26 illustrated in FIG. 1A.
[0103] The dilator 24 or sheath 26 may separately, or together,
form one or more passages to allow air or gas to escape or vent
from between the dilator 24 and sheath 26 and/or between the needle
and the dilator. The one or more passages may further be sized to
inhibit the flow of a liquid, such as blood, while allow air to
pass therethrough. The one or more passages may be in the wall of
the sheath 26, the sheath hub, the dilator hub 38, an exposed
section of the dilator shaft, and/or formed between adjacent
surfaces of the dilator 24 and sheath 26. For example, FIG. 3A
shows longitudinally arranged grooves 75 that are formed between
adjacent surfaces of the dilator 24 and sheath 26. Such venting
passages can also be labyrinth. The adjacent surfaces form a luer
slip connection between the sheath 26 and dilator 24.
[0104] FIG. 3F is a cross-sectional view taken along lines 3F-3F in
FIG. 3A and shows the grooves 75 equally spaced, though not
required to be equally spaced, about the circumference of the luer
slip surface. The grooves 75 are sized to allow air to escape from
between the dilator and the medical article, such as a sheath, when
the blood flash occurs. As mentioned above, the one or more
passages need not be in the form of a surface groove 75 and instead
may be in the form of an opening or passageway.
[0105] In the illustrated embodiment, the one or more passages
allow air to pass through the luer connection between the sheath
and dilator hubs. In the illustrated embodiment, a distal end of
the passage 75 or is located on the distal side of the luer
connection with the proximal end of the passage 75 being located on
the proximal side of the luer connection.
[0106] The one or more passages may be sized to filter blood or
other liquid or may include a filter or other structure that
inhibits the passage of a liquid while allowing the passage of air.
For example, the sheath itself may include one or more passages in
the form of small openings, pores or porous material. Depending on
the size of the one or more passages and the expected size of the
fluid molecules and formed elements (e.g. red blood cells), the one
or more small openings, pores or porous material in the sheath can
form a porous vent that allows air to pass yet retain blood.
[0107] A method of manufacturing a ridged dilator will now be
described. First, an extrusion process is used to create a long
tubular body having one or more longitudinal grooves or channels on
its outer diameter (OD) or within the substance of the dilator. The
long tubular body exceeds the required length of a single dilator
and preferably has a length that is many times greater than the
length of a single dilator. A manufacturing die is employed in the
extrusion process having geometry that reflects the desired
geometry for the inside and outside diameters of the dilator and
the thickness and circumferential span of the longitudinal grooves
or channels or interior channels. In the illustrated embodiment of
FIGS. 1-11, the long tubular body includes two longitudinal OD
channels on opposite sides of the body to enhance the balance of
the dilator within the sheath. However, a single channel can
provide a visible indicator for the blood flash. The two channels
preferably extend along the length of the extruded tubular body.
While the illustrated embodiment includes one or more channel
disposed between the dilator and the sheath, one or more channels
can in addition or in the alternative be formed between the needle
and the dilator, within the dilator, and/or within the sheath. In
some embodiments, the dilator 24 thus is made partially or
completely from clear, translucent, transparent, or semi-opaque
material to visualize the fluid flash within the channel.
[0108] With reference back to the illustrated embodiment, the
extruded tubular body is cut to the appropriate length for a single
dilator. In the preferred method, the two OD grooves extend for the
entire length of the cut dilator.
[0109] A tipping process is then employed on an end of the cut
dilator to reform the tip. An end of the cut dilator is forced into
a die/mandrel having geometry that matches the desired geometry of
the tip of the finished dilator. The desired geometry is selected
depending on, for example, the inside diameter of the sheath. It is
desirable for the sheath and dilator to form a close fit or seal
near the tip to promote blood flow in the proximal direction up the
channel formed between the grooved dilator and sheath. Preferably,
the OD of the dilator in the tip region tapers in the distal
direction.
[0110] When in the die/mandrel, thermal energy is applied to the
tip to reform the tip to match the die/mandrel. The thermal energy
may be applied by any known technique, including using radiant
heating from an infrared or RF heat source. As part of the tipping
process, the dilator in the tip region is reformed so that the
grooves are essentially removed. With the grooves removed, the
dilator is able to form the close fit or seal with the sheath near
the tip. The grooves are maintained along the remainder of the
dilator on the proximal side of the location where the tip of the
sheath 26 sits on the dilator. After removal from the die/mandrel,
the tip end of the dilator may be cleaned and cut as necessary to
remove any manufacturing remnants.
[0111] The one or more fenestrations in the dilator is cut through
the dilator near the tip region and in or near the groove. Each
fenestration may be cut by any known means, including a drill or
laser. Further, the cutting device may be moved with respect to the
dilator or vice versa to achieve an oblong or other shape for the
fenestration.
[0112] The end of the dilator opposite from the tip end can be
flared to facilitate over molding the dilator hub onto the
dilator.
[0113] FIG. 4A is a plan view of the sheath 26 of the embodiment
depicted in FIG. 1A. FIG. 4B is a cross-sectional view of the
sheath 26 of the embodiment depicted in FIG. 4A, taken along line
4B-4B. FIG. 4C is an enlarged proximal end view of the sheath 26 of
FIG. 4A. FIG. 4D is an enlarged perspective view of the sheath hub
42 of the sheath 26 of FIG. 4A. As shown in FIGS. 4A-4D, the sheath
26 may comprise a sheath body 40, a sheath hub 42, a distal portion
90, and a proximal region 92. The sheath body 40 may be made
partially or completely from clear, translucent, transparent, or
semi-opaque material. The sheath body 40 can also include one or
more radiopaque markers, such as, for example, barium sulfate
stripes. In a preferred embodiment, the sheath includes two such
radiopaque stripes disposed on diametrically opposite sides of the
body 40.
[0114] The sheath body 40 may be a single piece sheath through
which a catheter or other medical article (e.g., a guidewire) is
inserted into the vessel. In such an embodiment, the sheath body 40
forms a conduit for insertion of the catheter or other medical
article (e.g., a guidewire). In addition to providing a conduit,
the sheath or a portion of the sheath can form a lumen that is in
addition to the lumen(s) of the catheter. For example, an
equivalent to a triple lumen catheter can be formed by inserting a
dual lumen catheter through the sheath body 40 with the sheath body
40 itself forming a third lumen.
[0115] It may be advantageous to remove a portion or the entire
sheath body 40 depending on the type of catheter or medical article
that is to be inserted into the vessel after employing the access
device 20. For example, after the catheter or other medical article
is inserted into the vessel, a portion of the sheath body 40 can be
separated or peeled-away and removed. A peel-away sheath can
include perforations, serrations, skives, or other structures, or
include other materials (e.g., PTFE with bismuth) to allow the
physician or healthcare provider to remove easily a portion or the
entire sheath body 40.
[0116] The sheath hub 42 may include a luer slip connection and a
lock member 94. The locking member 94 may comprise a locking or
attaching structure that mates or engages with a corresponding
structure. For example, the lock member 94 can be a luer connection
94 which can be configured to engage with the second luer
connection 80 of the dilator hub 38.
[0117] The sheath hub 42, as best seen in FIG. 4C and 4D,
preferably is designed so that the locking mechanism or second luer
connection 80 of the dilator hub 38 can enter the sheath hub 42
substantially unobstructed. However, in use, once the sheath hub 53
is placed at a desired location over the dilator shaft 36, the
physician or healthcare provider can push, pull, or twist the
sheath hub 42 and possibly disengage or engage the locking member
94 with a corresponding connector on another medical article. The
locking member 94 can be, for example, a luer connection, a
protruding bump, dent, etc., that creates a mechanical fit so that
the dilator hub 38 and the sheath hub 42 are releasably
interlocked. In the illustrated embodiment, the locking member 94
of the sheath hub 42 comprises a luer connection. The sheath hub 42
preferably engages with the corresponding second luer connection 80
on the dilator hub 38. Preferably, the locked position can be
disengaged or engaged by pulling, squeezing, pushing or twisting
the dilator hub 38 relative to the sheath hub 42.
[0118] In some embodiments, the sheath hub 42 can comprise a lip
95. The lip 95 can be threaded to allow the sheath hub 42 to attach
to other medical articles with a corresponding locking feature.
[0119] The sheath hub 42 preferably comprises one or more surface
features to allow the physician or healthcare provider to easily
grasp or manipulate the sheath 26 and/or access device 20. In the
illustrated embodiment, the sheath hub 42 includes a squared grip
96 and ridges 98.
[0120] In additional embodiments, the sheath hub 42 may comprise
radially extending wings or handle structures to allow for easy
release and removal of the sheath body 40 from other parts of the
access device 20. In some applications, the wings are sized to
provide the healthcare provider with leverage for breaking apart
the sheath hub 42. For example, the sheath hub 42 may comprise a
thin membrane connecting the halves of the sheath hub 42. The
membrane is sized to keep the halves of the sheath hub 42 together
until the healthcare provider decides to remove the sheath hub 42
from the access device. The healthcare provider manipulates the
wings to break the membrane and separate the sheath hub 42 into
removable halves.
[0121] FIG. 5A is a perspective view of the guidewire section 28 of
the embodiment depicted in FIG. 1A. FIG. 5B is a plan view of the
guidewire section 28 depicted in FIG. 5A, which preferably includes
the guidewire hub 46. The guidewire hub 46 can comprise one or more
surface features to allow the physician or healthcare provider to
easily grasp or manipulate the guidewire hub 46 and/or access
device 20. In the illustrated embodiment, the guidewire hub 46
comprises one or more ridges 110. In a pre-loaded state, the outer
surface of the guidewire hub 46 engages with a locking mechanism
130 on the track 30 when the guidewire hub 46 is in a third
position 125.
[0122] In some embodiments, the guidewire 44 may form a close fit
with the inside diameter of the needle body so as to provide a
self-aspirating function when retracted. For example, an outside
diameter of the guidewire 44 may be selected to form a close fit
with the needle along the length of the guide wire or along only a
portion of the guidewire 44.
[0123] In some embodiments, the distal end portion of the guidewire
can have a reduced diameter in comparison to other sections of the
guidewire. The size of such reduced diameter section can be
selected to permit fluid to pass to the fenestration 56 in the
needle body even when the guidewire has been advanced beyond the
distal tip of the needle.
[0124] FIG. 6A is a perspective view of the track 30 of the
embodiment depicted in FIG. 1A. FIG. 6B is a plan view of the track
30 illustrated in FIG. 6A. FIG. 6C is a side view of the track 30
illustrated in FIG. 6A. As shown in FIGS. 6A-6C, the track 30 in
the illustrated embodiment comprises a distal portion 120, a
proximal portion 122, a distal locking member 124 that connects the
track to the dilator hub 38, a locking mechanism 128 that inhibits
further proximal and distal movement of the needle hub 34 once the
needle hub 34 is slid from the first position 121 to the second
position 123 along the track 30, and a locking mechanism 130 that
allows the guidewire hub 46 to attach to the track 30 when the
guidewire hub is in the pre-loaded state or third position 125.
Preferably, the track is made of polycarbonate material; however,
as explained below, other materials can be used.
[0125] The track 30 may further include a track section 132 of
reduced width as shown most clearly in FIGS. 6A and 6B. The reduced
width facilitates assembly of the needle hub to the track 30. The
illustrated embodiment includes a rib 133 on the distal portion 120
of the track 30. The rib 133 provides additional structural
reinforcement between the distal locking member 124 and the
remainder of the track 30.
[0126] As illustrated in FIG. 1A, the distal locking member 124
connects to the dilator 24 and allows the track 30 to extend
proximally from the dilator 24. For example, the locking member 124
can comprise two curved arms 124 that connect to the dilator hub 38
between the dilator hub lip 77 and the dilator hub base 79. The
locking member 124 limits movement of the track 30 in a distal or
proximal direction relative to the dilator hub 38 but allows the
track 30 to rotate freely around the dilator hub 38.
[0127] FIG. 6D is an enlarged view of a portion of the embodiment
depicted in FIG. 6B. As shown, the locking mechanism 128 is formed
by varying the width of the track in the region of the second
position 123. For example, the illustrated embodiment includes a
track section 134 of increasing width in the distal direction, a
track section 136 of reduced width distal to the track section 134
of increasing width, and two finger elements 138. The two finger
elements 138 project from the distal end of the track section 136
toward the proximal end of the track 30 and flare away from the
longitudinal axis of the track 30.
[0128] FIG. 6E is an enlarged view of a portion of the embodiment
depicted in FIG. 6B. The locking mechanism 130 is formed by a clip,
clasp or other structure that engages with a portion of the
guidewire hub or with a portion of the track 30 when the guidewire
hub is in the third position. Some or all of the engagement
structure may be part of the track 30, be part of the guidewire
hub, or be split between the track 30 and guidewire hub. In the
illustrated embodiment, the locking mechanism 130 extends from the
track 30 and engages with the guidewire hub. The locking mechanism
130 comprises a rectangular element 140 protruding from the track
30, two track arms 142 projecting from the track 30 distal to the
rectangular element 140, and a stop 144 protruding from the track
30 distal to the track arms 142.
[0129] In the illustrated embodiment, the locking mechanism between
the needle hub and the dilator resides on the proximal side of the
dilator hub. In other embodiments, however, the locking mechanism
can be disposed at other locations as well. For example, where the
locking mechanism includes two pivotal levers which are joined by a
locking hinge, the locking mechanism can be disposed radially
relative to the needle hub. In such an embodiment, one lever is
pivotally coupled to the dilator and the other lever is pivotally
coupled to the needle. When the needle hub is moved away from the
dilator hub, the levers straighten to a point where the hinge
locks. A similar effect can be obtained by a tether limiting
proximal movement of the needle hub relative to the dilator beyond
a particular point, thereby locking the components together. In a
further embodiment, an elongated structure can extend parallel to
the needle body from the needle hub within the dilator. Once the
needle hub is moved a sufficient distance away from the dilator,
additional structure of the locking mechanism (e.g., a detent)
engages the elongated structure to inhibit further movement of the
needle relative to the dilator. Accordingly, as illustrated by
these additional embodiments, the locking mechanism operating
between the needle and the dilator can be disposed at a variety of
locations relative to the dilator hub.
[0130] FIG. 7A is an enlarged plan view of the access device of the
embodiment depicted in FIG. 1A pre-loaded with the guidewire. FIG.
7B is a side view of the embodiment depicted in FIG. 7A. FIG. 7C is
a cross-sectional view of the embodiment depicted in FIG. 7A along
line 7C-7C. FIG. 7D is a proximal end view of the access device 20
of FIG. 7A. In this pre-loaded state, the guidewire hub 46 is
locked to the track 30 when the guidewire hub 46 is located in a
third position 125. In this position, the guidewire hub 46 can be
secured to the track 30 between the rectangular element 140 and the
stop 144. For example, the guidwire hub 46 can releasably lock
between the rectangular element 140 and the stop 144. In addition,
the track arms 142 can further secure the guidewire hub 46 to the
track 30. This locking mechanism can arrest unintended rotational
and axial movement of the guidewire 44 at least in the distal
direction when the guidewire hub 46 is in the third position 125.
Of course, the healthcare provider may disengage the guidewire hub
46 from the track 30 to allow distal movement of the guidewire
through the access device 20.
[0131] In the preloaded-state illustrated in FIGS. 7A-7C, the
needle hub 34 is locked to the dilator hub 38 when the needle hub
34 is in the first position 121. Preferably, in the locked
position, the openings or fenestrations in the needle and dilator
are in register or in alignment with each other. When locked, the
needle 22 and the dilator 24 are inhibited from at least
unintentional rotational and axial movement relative to each other.
By preventing unintentional rotation of the dilator hub with
respect to the needle 34, the fenestrations or openings maintain
their general alignment.
[0132] In the pre-loaded state, the dilator hub 38 is secured to
the sheath hub 42. This can inhibit at least unintentional
rotational and axial movement between the dilator 24 and the sheath
26. In embodiments where the sheath hub 42 and the dilator 24 have
only a luer slip connection, the dilator 24 and sheath hub 42 may
rotate relative to each other.
[0133] FIG. 8A is a plan view of the embodiment depicted in FIG. 1A
that illustrates an operational step of one method of using the
access device 20. FIG. 8A depicts the needle body 32 of the access
device 20 inserted into a vessel 148, such as a vein. While the
described method refers to vascular access, the access device 20
also can be used to access and place a catheter or sheath into
other locations within a patient's body (e.g., for draining an
abscess) and for other purposes.
[0134] FIG. 8B is an enlarged plan view of the portion of the
embodiment illustrated in FIG. 8A which is circled by line 8B-8B.
FIG. 8C is an enlarged plan view of the portion of the embodiment
illustrated in FIG. 8B which is circled by line 8C-8C. FIG. 8D is
an enlarged cross-sectional view of the embodiment depicted in FIG.
8C along line 8D-8D.
[0135] As noted above, the needle body 32 comprises one or more
side openings 56 in its side wall. The dilator shaft 36 comprises
one or more side openings 74. The side openings 56, 74 may have the
same or different shapes as well as aspect ratios. In the
illustrated embodiment, the side opening 56 in the needle body 32
has a different aspect ratio than the side opening 74 in the
dilator shaft 36. The side opening 56 in the needle body 32 is
elongated in one direction (e.g., substantially parallel to the
longitudinal axis of the needle body 32). The side opening 74 in
the dilator shaft 36 is elongated in a different direction (e.g.,
along the circumference of the dilator shaft 36). Having offset
elongated openings 56, 74 in the needle body 32 and the dilator
shaft 36 increases the likelihood that the openings 56, 74 in the
needle body 32 and dilator shaft 36 will be sufficiently aligned so
that blood flows through the needle side opening 56 and dilator
side opening 74. FIGS. 8A-D illustrate the alignment between only
one set of corresponding side openings. Other sets of side openings
can also be aligned or be misaligned depending upon the relative
orientations of the needle body 32 and the dilator shaft 36.
[0136] In the illustrated embodiment, the dilator shaft 36 is
coaxially positioned to minimize an annular space 150 between the
needle body 32 and the dilator shaft 36. The inner surface 152 of
the dilator shaft 36 need not, though it can, lie directly against
the outer-surface 154 of the needle body 32. Preferably, in this
embodiment, the annular space 150 between the outer-surface 154 of
the needle body 32 and the inner surface 152 of the dilator shaft
36 is minimized to inhibit the flow of blood or its constituents
(or other bodily fluids) into the annular space 150 between the
dilator shaft 36 and needle body 32. Advantageously, this feature
minimizes the blood's exposure to multiple external surfaces and
reduces the risk of contamination, infection, and clotting.
[0137] As illustrated in FIG. 8A, the dilator shaft 36 is coaxially
mounted to the needle body 32 such that at least part of one side
opening 56 disposed on the needle body 32 is rotationally aligned
with at least part of one side opening 74 on the dilator shaft 36.
Preferably, the needle body 32 and dilator shaft 36 maintain
rotational alignment so that blood flows through the needle side
opening 56 and dilator side opening 74.
[0138] The sheath body 40, as noted previously, is preferably made
partially or completely from clear, semi-opaque, translucent, or
transparent material so that when blood flows into the needle body
32, (1) through the needle side opening 56, (2) through the dilator
side opening 74, and (3) into a channel 156, the physician or
healthcare provider can see the blood. In some modes, the channel
156 is formed between the dilator shaft 36 and the sheath body 40
and defined by one or more ridges 76 on the dilator shaft 36. In
some modes, the channel 156 is formed within a wall of the dilator
shaft 36 with the dilator shaft 36 preferably comprising a
transparent material. Blood will indicate to the physician or
healthcare provider that the bevel tip 54 of the needle body 32 has
punctured a vessel 148.
[0139] In some embodiments, the needle body 32 and dilator shaft 36
may (both) have multiple side openings where some or all of these
side openings can be rotationally aligned.
[0140] The channel 156 can have an axial length that is almost
coextensive with the length of the sheath 26. In other embodiments,
the channel 156 can be significantly smaller than the elongated
channel 156 just described. For example, but without limitation,
the channel 156 can be disposed within a distal, mid and/or
proximal portion(s) of the sheath 26. The channel 156 alternatively
can have a linear, curved or spiral shape along an axial length of
the sheath 26 or can be formed by a plurality of such shapes. The
channel 156 may have various thicknesses and span angles. The
thickness of the channel 156 can range from almost close to zero to
0.010 inches. Preferably, the channel 156 has a thickness of about
0.0005 to about 0.003 inches. More preferably, the channel 156 can
have a thickness of about 0.001 inches to about 0.002 inches. The
channel 156 can have a span angle .PHI. about the axis of the
dilator 24 of about 30 degrees to about 210 degrees or more, but
preferably less than 360 degrees. More preferably, the channel 156
can have a span angle .PHI. of about 60 to 150. In the illustrated
embodiment, the channel 156 spans 120 degrees. The thickness and
span angle .PHI. can be chosen so as to optimize the capillary
action that occurs within the channel 156 as fluid (e.g., whole
blood) enters the channel 156 as may further be selected based on
the expected pressure in the body cavity and viscosity of the
liquid.
[0141] FIGS. 8E-8G are graphs of test data illustrating how quickly
a fluid is drawn up the surfaces of the channel 156 when the span
angle is 120 degrees, the contact angle (.theta.) is 5 degrees, and
the circumferential length (H) is 0.64 mm at 60 degrees. On each
graph, the filling length (mm) is plotted on the y-axis, and time
(seconds) is plotted on the x-axis. The tests were performed at
hydrodynamic pressures similar to pressures experienced in
peripheral vessels. FIG. 8E illustrates the rate fluid is drawn up
a channel 156 with a gap height width of 0.002 inches, FIG. 8F
illustrates the rate fluid is drawn up a channel 156 with a gap
height width of 0.001 inches, and FIG. 8G illustrates the rate
fluid is drawn up a channel 156 with a gap height width of 0.0005
inches. As shown in FIGS. 8E-G, fluid is drawn up the fastest in a
channel with a gap height width of 0.0005 inches, followed by a
channel with a gap height width of 0.001 inches, followed by a
channel with a gap height width of 0.002 inches.
[0142] The shape of the channel 156 described above and the
resulting capillary action was optimized for use with whole blood
as opposed to other fluids having a different viscosity than whole
blood (e.g. leukocytes, pus, urine, plasma). However, the shape of
the channel 156 is not limited to the disclosed shape and may be
optimized for draining other liquids, such as pus. Further, the
shape of the channel 156 described above was optimized for
peripherally located vessels where the pressure in the vessel
enhances the capillary action and resulting blood flash as well as
for vessels located in the regions where the pressure may be low.
For example, in the thorax region of the body, the expected
pressure in the veins may be lower than in a peripherally located
vein when the patient breathes. A different size of the channel for
use of the access device 20 in other regions of the body may be
employed taking into account the expected pressure within the
vessel or body cavity.
[0143] Additionally, an outer-surface 160 of the dilator shaft 36
and/or an inner surface 158 of the sheath body 40 can be coated
with a substance to promote or enhance the capillary action within
the channel 156. For example a hydrophilic substance can be used to
coat outer-surface 160 of the dilator shaft 36 and/or the inner
surface 158 of the sheath body 40 to enhance capillary action.
Similarly, one or both of these components can be made of a
hydrophilic material. A hydrophilic substance additionally can be
applied to the outer surface of the sheath 26 to act as a lubricant
to ease insertion of the sheath 26 into a patient. Other lubricants
or lubricous coatings can be used on the exterior of the sheath 26
or at least the outer surface of the sheath can be formed of a
lubricous material. Additionally, the sheath 26 can be coated or
formed with agents (e.g., heparin), which elute from the sheath, to
facilitate the clinical application of the access device 20.
[0144] FIG. 8H is a cross sectional view of the embodiment depicted
in FIG. 8C along line 8H-8H. In this region of the illustrated
access device 20, the sheath body 40 is coaxially positioned to
minimize the annular space 157 between the sheath body 40 and the
dilator shaft 36 while still allowing relative movement of the
sheath body 40 and the dilator shaft 36. The inner surface 158 of
the sheath body 40 need not, though it can, lie directly against
the outer-surface 160 of the dilator shaft 36. The annular
interface 157 between the outer-surface 160 of the dilator shaft 36
and the inner surface 158 of the sheath body 40 may be reduced in
this region to inhibit the distal flow of blood or its constituents
(or other bodily fluids) from the opening 74 in the dilator shaft
36.
[0145] FIG. 8I is an enlarged plan view of the portion of the
embodiment illustrated in FIG. 8A which is circled by line 8I-8I.
FIG. 8J is a cross-sectional view of the embodiment depicted in
FIG. 8I. FIGS. 8I and 8J illustrate the needle hub 34 locked to the
dilator hub 38 when the needle hub is in the first position 121.
The dilator shaft 36 may be coaxially mounted to the needle body 32
by slipping a hollow section 84 of the dilator shaft 36 over the
needle body 32 and releasably securing the dilator hub 38 to the
needle hub 34. The proximal end 86 of the dilator hub 38 is
configured to mechanically fit and interlock with the needle hub
34.
[0146] The dilator shaft 36 may be releasably mounted to the needle
body 32 so that the dilator shaft 36 can be mounted and released,
or vice versa, from a coaxial position relative to the needle body
32. This locking mechanism can inhibit at least some unintentional
rotational and axial movement between the needle 22 and the dilator
24 when the needle hub 34 is in the first position. As shown, the
needle hub 34 may have a luer connection 64 that locks to the luer
connection 78 of the dilator hub 38. Furthermore, the needle hub 34
may also have latch element 66 that locks to the opening 82 in the
dilator hub 38.
[0147] In addition, FIGS. 8I and 8J illustrate the dilator hub 38
engaged with the sheath hub 42 when the access device 20 is
inserted into a vessel 148. Preferably, the proximal end 86 of the
sheath hub 42 is configured to mechanically fit and releasably
engaged with the dilator hub 38. As shown, the luer connection 80
in the dilator hub 38 can engage with the lock member 94 of the
sheath hub. The resulting friction fit can inhibit at least some
unintentional rotational and axial movement between the dilator 24
and the sheath 26 when the access device 20 is inserted into a
vessel 148.
[0148] FIG. 9A is a side view of the embodiment depicted in FIG. 1A
that illustrates a further operational step of the access device
20. FIG. 9A depicts the guidewire 44 of the access device 20
advanced in a distal direction into a vessel 148. This can be
achieved by advancing guidewire hub 46 from the third position 125
in a distal direction. The guidewire hub 46 is then locked to the
needle hub 34 when the needle hub 34 is in the first position
121.
[0149] FIG. 9B is an enlarged side view of the portion of the
embodiment illustrated in FIG. 9A which is circled by line 9B-9B.
FIG. 9C is a cross-sectional view of the embodiment depicted in
FIG. 9B. FIG. 9C illustrates the locking mechanism between the
guidewire hub 46 and the needle hub 34. Preferably, the guidewire
hub 46 is configured to mechanically fit and releasably or
irreversibly interlock with the needle hub 34. As shown, the
guidewire hub 46 includes a nub 162 on the inner surface of the
guidewire hub 46. The nub 162 of the guidewire hub can lock onto
the needle hub 34 by advancing the guidewire hub 46 in a distal
direction until the nub 162 is secured within the threaded groove
on the lip of the needle hub 46. In other embodiments, the
guidewire hub 46 can lock to the needle hub 34 via corresponding
threaded elements.
[0150] FIG. 10A is a side view of the embodiment depicted in FIG.
1A that illustrates another operational step of the access device
20. FIG. 10A depicts the dilator shaft 36 and the sheath body 40
advanced in a distal direction into a vessel 148. This can be
achieved by releasing the dilator hub 38 from the needle hub 34 and
advancing the dilator 24 and sheath 26 in a distal direction
relative to the needle hub 34 along the guidewire and needle. FIG.
10A further illustrates the proximal movement of the needle 22 and
guidewire section 28 relative to the dilator 24 and the sheath 26.
The needle hub 34 will lock to the track 30 when the needle hub 36
reaches the second position 123.
[0151] FIG. 10B is an enlarged rear view of the portion of the
embodiment illustrated in FIG. 10A which is circled by line
10B-10B. As depicted in FIG. 10B, the needle hub 34 locks onto the
track 30 via the locking mechanism 128 in the second position 123.
The needle hub tangs 68 slide in a proximal direction over the
track fingers 138 and the tangs 68 can lock into place between the
track fingers 138 and the track section of increasing width 134.
This arrests and, more preferably, substantially irreversibly
prevents axial movement of the needle body 32 at least in the
distal direction when the needle hub 34 is in the second position
123. In the illustrated embodiment, the locking mechanism 128
irreversibly prevents the needle hub 34 from moving in either the
proximal or distal directions once engaged. Furthermore, the distal
tip 54 of the needle 22 is drawn into the dilator 24 to sheath the
distal tip 54 when the needle hub 34 is in the second position 123.
Thus, this locking mechanism 128 inhibits the bevel tip 54 disposed
on the distal portion 50 of the needle body 32 from being advanced
beyond the distal end of the dilator shaft 36 once the dilator
shaft 36 has been advanced over the needle body 32 during use. The
dilator shaft 36 thus sheaths the sharp bevel tip 54 of the needle
body 32 to inhibit accidental needle sticks from occurring.
[0152] FIG. 11A is a side view of the embodiment depicted in FIG.
1A that illustrates the final operational step of the access device
20. FIG. 11A illustrates the removal of the guidewire 44 and the
dilator shaft 36 from the vessel leaving the sheath body 40
properly inserted within the vessel 148. FIG. 11B is an enlarged
plan view of the portion of the embodiment illustrated in FIG. 11A
which is circled by line 11B-11B. As clearly shown in FIG. 11B, the
distal end of the dilator shaft 36 and the guidewire 44 extend
beyond the sharp bevel tip 54 of the needle body 32 to inhibit
accidental needle sticks from occurring.
[0153] As noted above, having openings 56, 74 in the needle body 32
and dilator shaft 36 with different aspect ratios will increase the
likelihood that the openings 56, 74 in the needle body 32 and
dilator shaft 36 will be aligned so that blood flows substantially
unobstructed through the needle side opening 56 and dilator side
opening 74.
[0154] In the following embodiments, structure from one embodiment
that is similar to structure from another embodiment share the same
root reference number with each embodiment including a unique
suffix letter (32, 32A, 32B, etc.). FIG. 12A is a plan view of
another embodiment of the openings 56, 74 in the needle body 32 and
dilator shaft 36 illustrated in FIGS. 8B and 8C. FIG. 12B is an
enlarged cross-sectional view of the embodiment depicted in FIG.
12A along line 12B-12B. FIGS. 12A and 12B depict a needle body 32A
with an oblong opening 56A and a dilator shaft 36A with a circular
opening 74A. In other embodiments, the needle can have a circular
opening and the dilator can have an oblong opening. These
embodiments can increase the likelihood that the openings 56A, 74A
will be at least substantially aligned so that blood flows through
the needle side opening 56A and dilator side opening 74A.
[0155] FIG. 13A is a plan view of another embodiment of the
openings 56, 74 in the needle body 32 and dilator shaft 36
illustrated in FIGS. 8B and 8C. FIG. 13B is an enlarged
cross-sectional view of the embodiment depicted in FIG. 13A along
line 13B-13B. FIGS. 13A and 13B depict a needle body 32B with a
circular opening 56B and a dilator shaft 36B with a circular
opening 74B that is larger than the circular opening 56B in the
needle body 32B. In other embodiments, the opening in the dilator
can be smaller than the opening in the needle. These embodiments
can also increase the likelihood that the openings 56B, 74B will be
at least substantially aligned so that blood flows through the
needle side opening 56B and dilator side opening 74B.
[0156] As noted above, the dilator shaft 36 may have one or more
channels 156 formed between ridges 76 to form a conduit or flow
path between the sheath body 40 and the dilator shaft 36 to enable
the physician or health care provider to view the blood after the
bevel tip 54 of the needle body 32 has properly punctured a vessel
or the channels may be formed without ridges but by extruding axial
indentations of various possible configurations or by forming fully
enclosed channels within the dilator shaft or body.
[0157] FIG. 14A is a plan view of another embodiment of the ridges
76 depicted in FIG. 8C. FIG. 14B is an enlarged cross-sectional
view of another embodiment of the ridges 76 depicted in FIG. 8D.
FIGS. 14A and 14B depict two ridges 76C on the inner surface 158C
of the sheath body 40C that form at least one channel 156C between
the sheath body 40C and the dilator shaft 36C.
[0158] FIG. 15A is a plan view of another embodiment of the ridges
76 depicted in FIG. 8C. FIG. 15B is an enlarged cross-sectional
view of another embodiment of the ridges 76 depicted in FIG. 8D.
FIGS. 15A and 15B depict two ridges 76D on the inner surface 158D
of the sheath body 40D and two ridges 76E on the outer surface 160D
of the dilator shaft 36D that combine to form a channel 156D
between the sheath body 40D and the dilator shaft 36D. For example,
if the desired channel thickness is about 0.001 inches, the two
ridges 76D on the inner surface 158D of the sheath body 40D can
each be about 0.0005 inches thick and the two ridges 76E on the
outer surface 160D of the dilator shaft 36D can each be about
0.0005 inches thick.
[0159] FIG. 16A is a plan view of another embodiment of the ridges
76 depicted in FIG. 8C. FIG. 16B is an enlarged cross-sectional
view of another embodiment of the ridges 76 depicted in FIG. 8D.
FIGS. 16A and 16B depict many ridges on the outer surface 160E of
the dilator shaft 36E. Between adjacent ridges are splines 76F. The
splines 76F form a plurality of channels 156E between the sheath
body 40E and the dilator shaft 36E. One or more of the channels
156E can have the same span angle .PHI. or different span angles
.PHI.. In the illustrated embodiment the channels 156E have span
angles of 120 degrees and 23 degrees. In another embodiment, a
single ridge 76 can spiral around the exterior of the dilator along
its length.
[0160] FIG. 17 is an enlarged cross-sectional view through another
embodiment of the access device and shows the channel 156F formed
between a medical article or sheath body 40F and a dilator shaft
36F that have dissimilar shapes. In the illustrated embodiment, the
outer surface of the dilator shaft 36F has an oval shape while the
inner surface of the sheath body 40F has a round shape. The oval
dilator shaft 36F and the adjacent round sheath body 40F form one
or more channels or gaps 156F between the sheath body 40F and the
dilator shaft 36F. Of course the shapes of the sheath body 40F and
dilator shaft 36F are not limited to round and oval and may include
any other combination of dissimilar shapes in adjacent regions of
the sheath body 40F and dilator shaft 36F. In some modes, the outer
surface of the dilator shaft 36F is oblong and the inner surface of
the sheath body or medical article 40F is round. In some modes, the
outer surface of the dilator shaft 36F is round and the inner
surface of the medical article 40F is square. The gap or channel
156F can follow a longitudinal axis, a spiral path along the
longitudinal axis, a linear path along the longitudinal axis or
other path along the access device. In some modes, the linear path
is parallel to the longitudinal axis. The gap or channel 156F
thickness can vary along at least a portion of a length of the gap
or channel 156F.
[0161] In other embodiments, the channel 156 can be formed by
having one complete ridge on the inner surface of the sheath and
one complete ridge on the outer surface of the dilator. In other
embodiments, the inner surface of the sheath can have two ridges
that run 50% of the length of the channel 156 and the outer surface
of the dilator can have two ridges that run the remaining 50% of
the channel 156.
[0162] The embodiments herein described are comprised of
conventional, biocompatible materials. For example, the needle
preferably consists of ceramic, a rigid polymer, or a metal such as
stainless steel, nitinol, or the like. The other elements can be
formed of suitable polymeric materials, such as polycarbonate,
nylon, polyethylene, high-density polyethylene, polypropylene,
fluoropolymers and copolymers such as perfluoro
(ethylene-propylene) copolymer, polyurethane polymers or
co-polymers.
[0163] As noted above, the present access device can be used to
place a catheter at other locations within a patient's body. Thus,
for example, but without limitation, the access device can be used
as or with a variety of catheters to drain fluids from abscesses,
to drain air from a pneumotorax, and to access the peritoneal
cavity. In such applications, body fluids flow into the viewing
space to indicate when the needle has been properly placed.
[0164] Although this invention has been disclosed in the context of
certain preferred embodiments and examples, it will be understood
by those skilled in the art that the present invention extends
beyond the specifically disclosed embodiments to other alternative
embodiments and/or uses of the invention and obvious modifications
and equivalents thereof. In addition, while a number of variations
of the invention have been shown and described in detail, other
modifications, which are within the scope of this invention, will
be readily apparent to those of skill in the art based upon this
disclosure. It is also contemplated that various combinations or
sub-combinations of the specific features and aspects of the
embodiments may be made and still fall within the scope of the
invention. Accordingly, it should be understood that various
features and aspects of the disclosed embodiments can be combined
with or substituted for one another in order to form varying modes
of the disclosed invention. Thus, it is intended that the scope of
the present invention herein disclosed should not be limited by the
particular disclosed embodiments described above, but should be
determined only by a fair reading of the disclosure and the claims
that follow.
* * * * *