U.S. patent application number 15/866821 was filed with the patent office on 2018-08-16 for fluid bypass device for valved catheters.
This patent application is currently assigned to AngioDynamics, Inc.. The applicant listed for this patent is AngioDynamics, Inc.. Invention is credited to Raymond J. Lareau.
Application Number | 20180229019 15/866821 |
Document ID | / |
Family ID | 50881749 |
Filed Date | 2018-08-16 |
United States Patent
Application |
20180229019 |
Kind Code |
A1 |
Lareau; Raymond J. |
August 16, 2018 |
Fluid Bypass Device for Valved Catheters
Abstract
Bypass elements for medical valves and methods of using the same
are disclosed. Embodiments of the invention include an insert
having a tip that is adapted to displace a valve element without
penetrating it, and a lumen that fluidly communicates with a lumen
of a valve housing distal to the valve element when the bypass
element is engaged. Bypass elements are used, in certain
embodiments, to facilitate fluid pressure and ECG signal
measurements through implanted medical devices including
catheters.
Inventors: |
Lareau; Raymond J.;
(Westford, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AngioDynamics, Inc. |
Latham |
NY |
US |
|
|
Assignee: |
AngioDynamics, Inc.
Latham
NY
|
Family ID: |
50881749 |
Appl. No.: |
15/866821 |
Filed: |
January 10, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13941745 |
Jul 15, 2013 |
9895524 |
|
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15866821 |
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61671226 |
Jul 13, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/0215 20130101;
A61M 2039/2426 20130101; A61M 39/221 20130101; A61M 2039/1072
20130101; A61B 5/0402 20130101; A61B 5/0245 20130101; A61M 25/0097
20130101; A61M 39/0693 20130101; A61M 2039/064 20130101; A61M 39/26
20130101; A61M 39/045 20130101; A61M 39/10 20130101 |
International
Class: |
A61M 39/10 20060101
A61M039/10; A61M 39/26 20060101 A61M039/26; A61B 5/0245 20060101
A61B005/0245; A61B 5/0215 20060101 A61B005/0215; A61B 5/0402
20060101 A61B005/0402; A61M 39/06 20060101 A61M039/06; A61M 39/04
20060101 A61M039/04 |
Claims
1. A bypass element for a valve, comprising: an insert tip
configured to displace one or more edges of a slit in a membrane of
a valve without penetrating said membrane; an insert connector
adapted to connect to a measurement device; and an insert lumen
extending between the insert tip and the insert connector, said
insert lumen permitting fluid flow between the tip and the
connector.
2. The bypass element of claim 1, wherein the insert tip has an
external diameter sized to fit within a lumen of a valve.
3. The bypass element of claim 1, further comprising: a proximal
insert portion including the connector; a distal insert portion
including the tip; a junction between said proximal and distal
insert portions; and a compressible element disposed about the
circumference of the insert at the junction and configured to
permit the insert to compress longitudinally.
4. The bypass element of claim 3 wherein the proximal and distal
insert portions can be rotated relative to one another.
5. The bypass element of claim 3, further comprising a sealing
member disposed at the junction of the proximal and distal insert
portions.
6. A system for bypassing a valved vascular access catheter,
comprising: a vascular catheter insertable into a patient; a valve
housing in fluid communication with the catheter, the valve housing
comprising: a valve lumen and a flexible membrane with a slit
therethrough, the membrane being disposed within the valve lumen
and the slit remaining closed when a pressure differential
thereacross remains below a predetermined threshold; and an insert,
comprising: a proximal connector engageable with the catheter; a
distal insert tip sized to fit within the valve lumen the valve
housing and to open the slit; and an insert lumen extending from
the proximal connector to the distal insert tip, the insert lumen
configured to permit fluid communication between the proximal
connector and the distal tip.
7. The system of claim 6, wherein the insert further comprises: a
proximal insert portion including the proximal connector; a distal
insert portion including the distal insert tip; a junction between
said proximal and distal insert portions; and a compressible
element disposed about the circumference of the insert at the
junction and configured to permit the insert to compress about a
longitudinal axis when the insert is engaged with a valve
membrane.
8. The system of claim 6, wherein the proximal and distal insert
portions can be rotated relative to one another at the
junction.
9. The system of claim 6, further comprising a sealing member
disposed at the junction of the proximal and distal housings.
10. A method of measuring a physical characteristic in a patient
having a catheter with a pressure activated valve, the pressure
activated valve comprising a membrane having at least one slit
therethrough, the slit opening in response to a fluid pressure in
excess of a predetermined threshold, the method comprising the
steps of: providing a an insert, comprising: a proximal connector
engageable with the catheter; a distal insert tip sized to fit
within a lumen of the pressure activated valve and open the at
least one slit in the membrane without penetrating the at least one
slit; and an insert lumen extending from the proximal connector to
the distal insert tip, the insert lumen configured to permit fluid
communication between the proximal connector and the distal tip;
placing the insert into the valve housing and contacting the
membrane, thereby permitting fluid transmission between the
catheter and the insert lumen; measuring the physical
characteristic through the insert lumen.
11. The method of claim 10, wherein the physical characteristic is
selected from the group consisting of a pressure wave, acoustic
wave and ECG wave.
12. The method of claim 10, further comprising the step of
determining a position of a distal tip of the catheter based on a
measured fluid pressure.
13. The method of claim 12, further comprising the step of
repositioning the distal tip of the catheter.
14. The method of claim 12, further comprising the step of
positioning the distal tip of the catheter in an optimal
position.
15. The method of claim 10, further comprising the step of
determining a position of a distal tip of the catheter based on a
measured ECG wave.
16. The method of claim 12, further comprising the step of
repositioning the distal tip of the catheter.
17. The method of claim 12, further comprising the step of
positioning the distal tip of the catheter in an optimal position.
Description
TECHNICAL FIELD
[0001] The present invention relates to systems and methods for
transmission and measurement of fluid through valved catheters.
BACKGROUND
[0002] There are a number of implantable medical devices used for
the repeated and prolonged access to a patient's vascular system or
other bodily conduits. Such devices include peripherally-inserted
central catheters ("PICC's"), central venous catheters ("CVC's"),
dialysis catheters, implantable ports, and midline infusion
catheters. These devices are typically implanted into a patient for
an extended period of time to allow for multiple treatments, such
as the delivery of therapeutic agents or dialysis treatments. Use
of such devices eliminates the need for multiple placements of
single-use devices, thus reducing the risk of infection and
placement complications, and reducing the overall cost of patient
care. Examples of such implantable medical devices include
BioFlo.TM. PICC's, Vaxcel.RTM. PICC's, Xcela.RTM. PICC's, and
Vaxcel.RTM. Plus Chronic Dialysis catheters (all from
AngioDynamics, Inc., Latham, N.Y.). Implantable devices such as
these have distal sections that reside within the vasculature, and
proximal sections that are typically outdwelling and include luers
for connection to fluid sources and other medical devices.
[0003] Because these devices remain in a patient's body for an
extended period of time, it is common practice to seal their
proximal ends between uses to prevent blood loss and infection.
Such a seal may be created with the use of a simple clamp placed on
the catheter line (e.g. the Morpheus.RTM. SMART PICC,
AngioDynamics, Inc., Latham, N.Y.), or with the use of an in-line
valve such as that found in the Vaxcel.RTM. PICC with PASV.RTM.
Valve Technology and described in U.S. Pat. Nos. 5,205,834 and
7,252,652, which are incorporated herein by reference. In-line
valves are pressure activated such that they open to allow for
fluid to be delivered through the valve upon the application of
some threshold pressure, above which the valve will open, and below
which the valve remains closed. Pressure activated valves may
advantageously prevent patient complications and infections. In
line catheter valves typically include a valve housing that defines
a lumen (referred to as the "valve lumen") and a valve element
disposed across the valve lumen to regulate fluid flow. The valve
element is normally closed, but opens in response to pressures
above a pre-defined threshold. Valve elements used in in-line
catheter valves are typically flexible slitted membranes such as
those disclosed in U.S. Pat. No. 5,843,044, which is incorporated
by reference herein.
[0004] It is often desirable to measure fluid pressures such as
blood pressure or central venous pressure through a catheter. It
may also be desirable to measure an ECG signal through a column of
saline extending from a distal catheter tip to a proximal extension
tube and luer. In the case of valved devices, however, the in-line
valve inhibits transmission of fluid pressure from the distal
catheter tip to the proximal luer. Current practice is to insert an
elongated instrument through the valve element (typically a slitted
membrane), but the insertion of elongated tools into the valve
lumen to measure blood pressure raises a risk of puncturing the
membrane or tearing, weakening, or otherwise permanently deforming
the membrane or its slits. Additionally, excessive displacement of
the edges of slit raises the risk that the edges will not return to
their fully closed, fully and flushly apposed positions, instead
returning to a folded or puckered position, and that gaps or edges
may exist through which fluids may leak, potentially leading to
thrombosis and/or infection. Accordingly, there is a need for
systems that permit the measurement of blood pressure through
catheters having in-line valves, preferably without the risk of
damaging the valve element.
SUMMARY OF THE INVENTION
[0005] The need described above is met by the present invention,
which relates in one aspect to a bypass element for a valve which
opens but does not penetrate the valve element, permitting fluid
communication across the valve element. In certain embodiments, the
insert includes an insert tip that displaces one or more edges of a
slit in a membrane without penetrating the slit, as well as an
insert connector connectable to a measurement device, which is in
fluid communication with the insert tip via an insert lumen that
permits fluid flow between the insert tip and the insert connector.
The insert may have an outer diameter sized to fit within the valve
lumen. In various embodiments, the insert is longitudinally
compressible by means of a distal portion that includes the insert
tip, a proximal portion that includes the connector, and a
compressible element disposed at a junction of the proximal and
distal portions. The proximal and distal portions can optionally
rotate relative to one another, and the insert optionally includes
a sealing member disposed at the junction of the proximal and
distal portions to prevent leakage into or out of the insert lumen
at the junction of the proximal and distal insert portions.
[0006] In another aspect, the invention relates to a system for
measurement that includes a catheter insertable into a patient,
including a valve housing with a valve lumen and a flexible slitted
membrane positioned in the valve lumen which membrane remains
closed under pressures below a threshold value, and an insert that
includes an insert section that fits inside the valve lumen and
opens the slit, as well as a proximal connector that can be engaged
with the catheter and an insert lumen that runs between the insert
tip and the insert connector and permits fluid flow between them.
In certain embodiments the insert is longitudinally compressible by
means of a distal portion that includes the insert tip, a proximal
portion that includes the connector, and a compressible element
disposed at a junction of the proximal and distal portions. The
proximal and distal portions can optionally rotate relative to one
another, and the insert optionally includes a sealing member to
prevent leakage into or out of the insert lumen at the junction of
the proximal and distal portions.
[0007] In yet another aspect, the invention relates to a method of
measuring a physical characteristic in a patient with a catheter
having a pressure activated valve that, in turn, utilizes a
membrane with at least one slit, which slit opens in response to a
fluid pressure in excess of a predetermined threshold, as a valve
element. The method includes, in various embodiments, providing an
insert that has a section which fits inside the valve lumen,
contacts the membrane and opens the slit without penetrating it, as
well as a proximal connector that can be engaged with the catheter
and an insert lumen that runs between the insert tip and the insert
connector and permits fluid flow between them. The method also
includes placing the insert into the valve housing to permit fluid
transmission between the catheter and the insert lumen through the
open slit. The physical characteristic may be selected from the
group consisting of pressure waves, acoustic waves and ECG waves,
and the method may also include one or more of the steps of
determining the position of the distal tip of the catheter based on
the measured wave, and optionally repositioning the distal tip of
the catheter based on the measurements to achieve targeted tip
position. The method may also include positioning the distal tip of
the catheter in an optimal position during initial insertion of the
catheter.
DESCRIPTION OF THE DRAWINGS
[0008] The figures provided herein are not necessarily drawn to
scale, with emphasis being placed on illustration of the principles
of the invention.
[0009] FIGS. 1A-1B include schematic depictions of an insert and a
pressure activated valve in accordance with certain embodiments of
the invention.
[0010] FIGS. 2A-2B include schematic depictions of an insert
positioned within a pressure activated valve in accordance with
certain embodiments of the invention.
[0011] FIGS. 3A-3D include schematic depictions of valve inserts in
perspective and in cross-section according to certain embodiments
of the invention.
[0012] FIGS. 4A-4F include schematic depictions of valve inserts in
isolation or positioned within pressure activated valves according
to certain embodiments of the invention.
[0013] FIGS. 5A-5C include schematic depictions of various
relationships between valve inserts and valves of the invention, as
well as a schematic depiction of a prior art device.
[0014] FIGS. 6A-6B include schematic depictions of an insert having
an extension tube according to certain embodiments of the
invention.
[0015] FIGS. 7A-7B include schematic depictions of inserts having
branching insert lumens according to certain embodiments of the
invention.
DETAILED DESCRIPTION
[0016] Devices and methods to facilitate fluid transmission through
valved catheters are disclosed herein. Although physical
characteristics of a human body can be measured using elongated
tools inserted through valved catheters, this approach risks
damaging in-line catheter valves. The systems and methods described
herein avoid the risk of valve damage by using an insert that
displaces but does not penetrate a valve element.
[0017] Examples of medical devices that can be used with the
invention include, without limitation, peripherally-inserted
central catheters ("PICC's"), central venous catheters ("CVC's"),
dialysis catheters and midline infusion catheters that include
internal valves. While the examples set forth in this specification
focus on implantable catheters for vascular access, the systems and
methods of the invention are not limited to vascular devices but
are compatible with any medical device having an external valve,
including diagnostic and/or interventional catheters and sheaths
Similarly, while the examples set forth herein focus on valves
having a flexible diaphragm with one or more slits, the principles
of the invention are compatible with a variety of normally-closed
pressure activated valve designs.
[0018] With reference to the embodiments depicted in FIG. 1, a
system 100 according to the invention includes a valve housing 150.
The valve housing 150 includes a valve inlet 151, a valve outlet
152, a proximal valve lumen 153 and a distal valve lumen 154. The
proximal and distal lumens 153, 154 are separated by a valve
element 155 which, in preferred embodiments, is a flexible membrane
having at least one slit 156 therethrough. During ordinary valve
operation, the edges of the slit 156 remain together, and fluid
does not flow, unless a pressure differential thereacross exceeds a
predetermined threshold. When a pressure differential across the
valve element 155 exceeds the threshold, the membrane deforms so
that the edges of the slit 156 separate and fluid flows across the
valve from the side with higher pressure to the side with lower
pressure.
[0019] The system 100 also includes an insert 200, which has a
distal insert section 210, a proximal insert end 211, an insert
shaft 220, and an insert lumen 260 which extends from the distal
insert tip 210 to the proximal insert end 211 and is open to the
exterior of the insert in both places. In preferred embodiments,
the insert 200 also includes a proximal connector 240 that can be
attached to a pressure measurement and/or pressure transduction
apparatus, and a proximal external housing 230 that can connect to
the valve inlet 151 of the valve housing. Insert shaft 220 is sized
to fit within the proximal valve lumen 153 of the valve housing
150. Thus, insert shaft 220 preferably has a maximum outer diameter
that is slightly less than a minimum inner diameter of proximal
lumen 153. As shown in FIG. 1A, the length 250 of insert shaft 220
preferably corresponds to the length 157 of the proximal valve
lumen 153, so that when insert 200 is fully engaged with valve
housing 150, as shown in FIGS. 1B and 2B, the distal insert tip 210
of the insert 200 contacts valve element 155 and displaces the
flexible membrane it so that the edges of the slit 156 separate
from one another. In use, the insert 200 preferably does not
penetrate the valve element 155.
[0020] In some embodiments, after the insert 200 has been fully
engaged with the valve housing 150, the insert lumen 260 is aligned
with a gap between edges of the slit 156 so that fluid can flow and
pressure can be directly transmitted between the insert lumen 260
and the distal valve lumen 154. As shown in FIG. 2, the opening of
the insert lumen 260 at the distal insert tip 210 may be positioned
so that, as the insert 200 is inserted into the proximal valve
lumen 153 and the distal insert tip 210 approaches the membrane
155, the insert lumen 260 aligns with the slit 156 as shown in FIG.
2A. When the insert 200 is fully engaged with the valve 100, the
distal insert tip 210 of the insert presses into the valve element
155, displacing the edges of the slit 156 and creating a fluid
communication channel or gap 156' through which fluid can flow
between the insert lumen 260 and the distal valve lumen 154.
[0021] In some embodiments, however, the opening of the insert
lumen 260 is not aligned with the slit 156, and either one or both
of the opening of the insert lumen 260 and the slit 156 is offset
from the central longitudinal axis of the insert 200 and/or the
proximal and distal valve lumens 153, 154. In these embodiments,
the distal insert tip 210 presses into the valve element 155,
advantageously utilizing the elasticity of the membrane comprising
the valve element to stretch and open the slit or slits 156,
thereby permitting fluid flow and transmission of fluid pressure
across the valve element 155 and between the proximal and distal
lumens 153, 154. This in turn permits fluid flow and transmission
of fluid pressure between the insert lumen 260 and the distal valve
lumen 154.
[0022] With respect to the insertion of insert 200 into valve
housing 150, in preferred embodiments, the insert 200 contacts the
valve element 155, but does not penetrate the slit 156. As shown in
FIGS. 5A and 5B, the at least one slit 156 has proximal edges 156P
which face the proximal valve lumen 153 when the valve element 155
is closed, and distal edges 156D which faces the distal valve lumen
154 when the valve is closed. FIG. 5A shows an insert 200 of the
invention positioned in so that it contacts valve element 155 but
does not open the slit 156. When the valve is completely closed,
the entire distal surface of the valve element 155 is disposed
along the plane identified by reference line L.sub.1. As the insert
200 is advanced in the valve housing 150, the distal insert tip 210
displaces the edges of the slit 156 downward and outward, such that
the distal edge 156D of the slit 156 extend below reference line
L.sub.1. According to one embodiment, the inert is advanced no
further than the position shown in FIG. 5C: the edges of the slit
156 are pressed apart, but at all times the proximal edges 156P
remain proximal to the distal edges 156D of the slit 156 extend
below reference line L.sub.1. Preferably, the insert is advanced no
further than the position shown in FIG. 5B. The edges of the slit
156 are pressed apart, but the proximal edges 156P preferably do
not extend beyond the plane defined by reference line L.sub.1, and
remain proximal to the distal edges 156D, thereby minimizing the
risk of leakage due to imperfect resealing and/or damage to the
valve.
[0023] Inserts of the invention advantageously reduce the risk of
leakage due to imperfect resealing and/or valve damage relative to
devices disclosed in the prior art, such as the device 340
illustrated in FIG. 5C, in which an elongate member is inserted
into and through the slit 156. In the prior art device, the edges
of the slit 156 compress against the elongate member 340 and bulge
into distorted portions 157P and 156D. Compression and distortion
of the edges of the slit 156 in this manner increases the risks of
imperfect re-sealing and permanent damage to the valve element.
[0024] In some embodiments, the insert 200 includes features to
prevent the distal insert tip 200 from advancing too far. For
example, the proximal insert connector 240 may include a female
luer tip having a threading pattern selected so that, when the
proximal insert connector is fully screwed down, it does not extend
beyond the position shown in FIG. 5B.
[0025] FIG. 3 depicts an insert 200 according to two embodiments of
the invention. The embodiment in FIG. 3A-B corresponds to a
one-piece valve insert substantially as described above. In the
embodiment of FIG. 3C-D, the valve insert 200 includes proximal and
distal shafts 221, 222. A spring 270 or, in some embodiments, an
elastomeric member is positioned around the junction of the
proximal and distal shafts 221, 222, allowing for limited
compression and extension of the valve insert about its long axis.
The spring 270 preferably has a spring constant that is greater
than or equal to that of the flexible membrane comprising the valve
element 155 and is chosen to permit the distal insert tip 210 to
apply sufficient force to displace the valve element 155 and
separate the edges of the slit 156, but not enough to permit the
distal insert tip 210 to penetrate the valve element 155. The
combined length 250 of the proximal and distal shafts 221, 222
varies depending on the degree of compression, with the length 250
being slightly longer than the length 157 of the proximal valve
lumen 153 when the valve insert 200 is not engaged with the valve
housing 150, and compressing to fit within the proximal valve lumen
153 when engaged. In certain embodiments, the proximal and distal
shafts 221, 222 can be rotated relative to one another. Thus, in
embodiments in which the proximal external housing 230 of the valve
insert 200 rotates to fit over the exterior of the valve inlet
151--for example if the valve inlet 151 includes a male luer end
and the proximal external housing 230 includes a female luer
end--the proximal shaft 221 can rotate freely with the proximal
external housing 230 without translating that rotation to the
distal insert tip 210 or the flexible membrane.
[0026] To prevent fluid leakage out of the insert lumen 210 at the
junction of the proximal and distal shafts 221, 222, one or more
compressible sealing members 280, 281 may be utilized as shown in
FIG. 3C. Sealing members 280, 281 can be, for example, elastomeric
O-rings or any other suitable sealing mechanism known in the art.
The sealing member(s) may comprise any suitable material known in
the art, including silicone, EPDM, polyurethane, neoprene, FEP,
etc. In addition, the insert 200 may be configured to prevent
leakage of fluid through the proximal valve lumen 153. In some
embodiments, an outer diameter of a portion of the insert 200 which
is inserted into the proximal valve lumen 153 is slightly less than
the inner diameter of the proximal valve lumen 153, inhibiting or
preventing fluid flow around the insert 200. In some embodiments,
the proximal external housing 230 of the insert engages with the
valve inlet 151 to form a seal that prevents fluid leakage out of
the proximal valve lumen 153. In some embodiments, the insert 200
may have an outer diameter chosen to match up with an inner
diameter of the lumen, possibly preventing leakage.
[0027] The shape of the distal insert tip 210 is chosen to
facilitate proper function of the insert 200 while avoiding
damaging the valve element 155. In preferred embodiments, such as
the one shown in FIGS. 1-3, the distal tip is gently rounded. In
alternate embodiments, the valve has a conical distal insert tip
210, as is shown in FIG. 4A-C, or a stepped distal insert tip 210,
as is shown in FIG. 4D-F. The principle of operation remains the
same regardless of the tip shape: when the valve insert 200 is
fully engaged with the valve housing 150, as shown in FIGS. 4C and
F, the tip 210 displaces but does not penetrate the valve element
155 so that the edges of the slit 156 separate, and the insert
lumen 260 of the valve insert 200 is placed into fluid
communication with the distal valve lumen 154. The insert lumen 260
may open at the distal insert tip 210 in any suitable
configuration. In some embodiments, the opening of the insert lumen
260 at the distal insert tip 210 is circular, while in other
embodiments, the opening is rectangular, oval shaped, or otherwise
generally elongated so as to overlie a slit 156 of the valve
element 155, which arrangement may improve fluid flow and
transmission of pressures and/or prevent or minimize leakage around
the distal insert tip 210. The internal threading 230 and the
external threading 151 can be configured to align the rectangular
or oval opening along the same lateral axis as the slit.
[0028] In some embodiments, the insert 200 facilitates the
transmission and/or measurement of a pressure such as a central
venous pressure, a V-pressure wave generated by the filling of the
right atrium, an A-pressure wave generated by the contraction of
the right atrium, or any other pressure caused, directly or
indirectly, by a contraction of the heart of a patient which may be
desired to be measured. The insert 200 can also facilitate the
transmission and/or measurement of acoustic pressure waves such as
those caused by the opening and closing of one or more cardiac
valves, or acoustic waves caused by an external acoustic
generator.
[0029] In some embodiments, the insert 200 facilitates the accurate
placement of a distal end of a catheter, for example as disclosed
in U.S. patent application Ser. No. 12/594,869 by David Ziv,
published as Pre-Issue Publication number 2010/0049062, the entire
disclosure of which is hereby incorporated by reference for all
purposes. Using inserts of the invention, a distal end of a
catheter may be located within the vasculature of a patient and/or
may be placed in an optimal position for a given application.
Positioning of a catheter may be achieved, for example, by
measuring a delay time, phase shift, or amplitude of a pressure
wave and/or an acoustic wave (or any other wave or signal)
transmitted through a catheter and an insert of the invention
and/or comparing the measured value to a reference value. More
generally, inserts of the invention may be used to facilitate any
treatment that includes the measurement of a signal or a substance
that is transmitted through the valve of a catheter.
[0030] Using inserts of the invention, a catheter may be positioned
during an insertion procedure at a desired site. Additionally,
inserts of the invention may facilitate the repositioning of
catheter tips that have migrated from their initial positions, or
which need to be repositioned for other reasons.
[0031] Inserts of the invention may be configured to connect to a
pressure measurement apparatus, such as a manometer apparatus or a
digital pressure transducer system. In certain embodiments, the
proximal insert connector 240 comprises a female luer tip that can
be connected to and disconnected from a pressure measurement
apparatus. In other embodiments, any suitable connector known in
the art, including without limitation a threaded or unthreaded male
or female luer connector or a barb connector, can be used to
facilitate connections to a pressure measurement apparatus. The
connections can be either reversible or permanent.
[0032] Alternatively, inserts of the invention may include features
to facilitate direct pressure sensing, such as an electronic
pressure transducer for sensing a fluid pressure within the insert
lumen 260, a wire for conducting electrical signals generated by
the electronic pressure transducer to a central processor, and/or
an external valve for removing air from the fluid flow path that
includes the insert 200 and the valve housing 150.
[0033] Valve inserts of the invention can be used in any
application where it is desirable to measure a physical
characteristic or signal from a patient across a valve member in a
catheter. Valve inserts of the present invention are advantageously
used to facilitate measurement of fluid pressure with a valved
medical device. In a preferred embodiment, partially illustrated in
FIG. 1, an insert 200 is inserted into a valve housing 150 so that
the proximal external housing 230 connects to the valve inlet 151
of the valve housing 150 while the distal insert tip 210 engages
with the valve element 155 and displaces the edges of the slit 156,
placing the lumen 260 of the valve insert 200 in fluid
communication with the distal valve lumen 154 of the valve housing
150. In certain embodiments, before insertion into valve housing
150, the valve insert 200 is connected via the proximal connector
240, directly to a pressure measurement apparatus, or to a tube
that is connected to a pressure measurement apparatus. A
directional stopcock or other fluid control device can also
optionally be connected between the insert 200 and the pressure
measurement apparatus. After the proximal connector 240 is
connected to the pressure measurement apparatus, the entire system
is optionally flushed with a fluid solution, so that no air is
introduced into the system when the valve insert 200 is inserted
into the valve housing 150. After the insert 200 is fully engaged
with the valve housing 150, fluid can flow freely and pressure can
be equalized through the entire system 100. To verify that the
valve insert 200 is correctly inserted, an operator can push fluid
through the system, or withdraw fluid from the system 100 and
confirm that there is no resistance to fluid flow. An operator can
also push or withdraw fluid through the system to purge any air
from the system. Pressure measurements can then be taken through
system 100.
[0034] Another application for valve inserts according to the
invention includes transmission of fluid across a normally closed
valve for ECG measurement via a column of saline or other
transmission fluid. It is common to measure ECG signals from the
heart for various clinical applications, such as detection of
atrial fibrillation or ECG based tip location. The column of saline
runs from the tip of the catheter, such as a PICC line, through to
a proximal portion of the catheter, where the ECG signal is
measured. The valve insert can be used to bypass the valve using
the methods described above, so that the column of saline can be in
fluid communication with the proximal ECG measurement element. In
addition, the bypass element can itself have an incorporated ECG
measurement element, such as an electrode connected to an inner
valve insert wall in fluid communication with the lumen, or an
electrode connected to a valve insert extension tube or luer.
[0035] Valve inserts of the invention can be made using any
suitable method known in the art, including without limitation
injection molding, extrusion, machining and combinations thereof.
Valve inserts of the invention can be made of any suitable material
known in the art, including without limitation polycarbonate,
nylon, Pelox, polyethylene, polypropylene, FEP, ABS, metals
including stainless steel, and other suitable materials, which may
be combined in any suitable way. In some embodiments, at least a
portion of the insert 200 that includes the tip 210 is made of
stainless steel or another suitable metal.
[0036] In some embodiments such as those depicted in FIG. 6, the
insert includes an extension tube 290, which can be clamped using a
clamp 295 in order to prevent flow through the extension tube 290,
thereby preventing fluid leakage through the insert 200, for
example during insertion into the valve housing 150. In use, insert
200 is inserted into a valve housing 150 with the extension tube
290 clamped shut (FIG. 6B) in order to prevent reflux of blood
through the catheter and the insert upon engagement of the insert
tip 210 with the valve element 155.
[0037] While the examples described herein have focused on inserts
having substantially linear insert lumens 260, the insert lumen may
be non-linear, and may include branches, etc. Additionally, as
shown in FIG. 7, the insert may include one or more outlets at
sites other than the distal-most insert tip 210, corresponding to
valve membranes having multiple off-set slits.
[0038] The phrase "and/or," as used herein should be understood to
mean "either or both" of the elements so conjoined, i.e., elements
that are conjunctively present in some cases and disjunctively
present in other cases. Other elements may optionally be present
other than the elements specifically identified by the "and/or"
clause, whether related or unrelated to those elements specifically
identified unless clearly indicated to the contrary. Thus, as a
non-limiting example, a reference to "A and/or B," when used in
conjunction with open-ended language such as "comprising" can
refer, in one embodiment, to A without B (optionally including
elements other than B); in another embodiment, to B without A
(optionally including elements other than A); in yet another
embodiment, to both A and B (optionally including other elements);
etc.
[0039] The term "consists essentially of" means excluding other
materials that contribute to function, unless otherwise defined
herein. Nonetheless, such other materials may be present,
collectively or individually, in trace amounts.
[0040] Reference throughout this specification to "one example,"
"an example," "one embodiment," "an embodiment" or "some
embodiments" means that a particular feature, structure, or
characteristic described in connection with the example is included
in at least one example of the present technology. Thus, the
occurrences of the phrases "in one example," "in an example," "one
embodiment," "an embodiment" or "some embodiments" in various
places throughout this specification are not necessarily all
referring to the same example. Furthermore, the particular
features, structures, routines, steps, or characteristics may be
combined in any suitable manner in one or more examples of the
technology. Any headings provided herein are for convenience only
and are not intended to limit or interpret the scope or meaning of
the claimed technology.
[0041] Certain embodiments of the present invention have described
above. It is, however, expressly noted that the present invention
is not limited to those embodiments, but rather the intention is
that additions and modifications to what was expressly described
herein are also included within the scope of the invention.
Moreover, it is to be understood that the features of the various
embodiments described herein were not mutually exclusive and can
exist in various combinations and permutations, even if such
combinations or permutations were not made express herein, without
departing from the spirit and scope of the invention.
[0042] Variations, modifications, and other implementations of what
was described herein will occur to those of ordinary skill in the
art without departing from the spirit and the scope of the
invention. As such, the invention is not to be defined only by the
preceding illustrative description but by the spirit and scope of
the following claims.
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