U.S. patent application number 13/970655 was filed with the patent office on 2013-12-19 for valved catheters including high flow rate catheters.
The applicant listed for this patent is AngioDynamics, Inc.. Invention is credited to Brian J. Bergeron, H. Robert Moorehead.
Application Number | 20130338608 13/970655 |
Document ID | / |
Family ID | 34217424 |
Filed Date | 2013-12-19 |
United States Patent
Application |
20130338608 |
Kind Code |
A1 |
Moorehead; H. Robert ; et
al. |
December 19, 2013 |
Valved Catheters Including High Flow Rate Catheters
Abstract
A pressure activated two-way slit valve assembly is designed to
be used in combination with, but not limited to, a high flow rate
catheter to prevent accidental ingestion of air or loss of blood if
the closure cap comes off during non-use of the catheter. In
addition, the potential for occlusion of the catheter due to blood
clots in the catheter and catheter related infection is
substantially reduced. The pressure activated two-way slit valve
assembly includes a first end, a second end, a wall defining a
dumbbell shaped channel, and a flexible, thin disk having a slit
and positioned within the pressure activated two-way slit valve
assembly to reside within the dumbbell shaped channel. The slit and
the dumbbell shaped channel are sized to enable the slit to deform
in response to a predetermined pressure differential across the
slit to allow fluid to pass therethrough.
Inventors: |
Moorehead; H. Robert; (Salt
Lake City, UT) ; Bergeron; Brian J.; (Worcester,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AngioDynamics, Inc. |
Latham |
NY |
US |
|
|
Family ID: |
34217424 |
Appl. No.: |
13/970655 |
Filed: |
August 20, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13297888 |
Nov 16, 2011 |
8540685 |
|
|
13970655 |
|
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Current U.S.
Class: |
604/246 |
Current CPC
Class: |
A61M 39/22 20130101;
A61M 25/0045 20130101; A61M 39/223 20130101; A61M 2025/0031
20130101; A61M 2039/2446 20130101; A61M 2039/2426 20130101; A61M
2039/242 20130101; Y10T 137/7771 20150401; A61M 25/0075 20130101;
A61M 25/003 20130101; A61M 2025/0076 20130101; A61M 39/24
20130101 |
Class at
Publication: |
604/246 |
International
Class: |
A61M 39/22 20060101
A61M039/22 |
Claims
1-30. (canceled)
31. A catheter for fluid access to a site within a human body, the
catheter comprising: a conduit in fluid communication with a valve,
the valve comprising: a valve housing forming a valve lumen, a
flexible membrane disposed across the valve lumen, and a slit
extending through the flexible membrane; wherein the slit comprises
a first end portion, an intermediate portion, and a second end
portion, the intermediate portion configured between the first end
portion and the second end portion to form a continuous slit,
wherein the intermediate portion is substantially linear and lies
along an intermediate axis, the first end portion lies along a
first axis, and the second end portion lies along a second axis,
and wherein the first and second axis are nonparallel to the
intermediate axis.
32. The catheter of claim 31, wherein the first and second axis are
substantially linear.
33. The catheter of claim 32, wherein the first and second axis are
substantially perpendicular to the intermediate axis.
34. The catheter of claim 33, wherein the slit forms a
substantially H-shaped slit.
Description
TECHNICAL FIELD
[0001] This invention relates to valves for catheters. More
particularly, this invention relates to a valved high flow rate
catheter.
BACKGROUND INFORMATION
[0002] A high flow rate catheter is a tubular medical device
defining one or more lumens for transporting fluids to and/or from
a patient's body at a high flow rate, e.g. greater than 200 ml/min.
An example of a commonly used high flow rate catheter is a
hemodialysis catheter. Hemodialysis catheters include at least one
lumen for transporting a patient's waste-filled blood to a dialysis
machine for treatment, and another lumen for carrying the treated
blood back to the patient. Generally, hemodialysis catheters are
implanted within a patient's body such that a portion remains
within a blood vessel of the patient and a portion extends outside
of the patient body to be connected to the dialysis machine.
[0003] Conventionally, clamps that compress the lumens of the
hemodialysis catheter have been used to prevent blood loss and to
prevent ingestion of air through the catheter and into a patient's
blood stream (i.e., when the catheter is not in use). These clamps
tend to degrade the hemodialysis catheter, thereby requiring
medical professionals to remove and replace these catheters
frequently. In addition, conventional high flow rate catheters are
associated with a high occurrence of occlusion formation and
infections.
SUMMARY OF THE INVENTION
[0004] The present invention generally relates to valves for
catheters. While the present invention is described with regard to
high flow rate catheters, it should noted that the valves described
herein may be used in combination with any type of catheter.
Devices according to the invention are typically used to transport
fluids to and/or from a patient's body at a high flow rate when the
device is in use. It is an object of this invention to provide a
device that protects against catastrophic events when the catheter
is not in use, such as, for example, ingestion of air through the
device into the patient's blood stream or blood flowing
uncontrollably out from a patient's body. It is another object of
the invention to reduce occlusion formation and infections
associated with conventional high flow rate catheters.
[0005] In one aspect, the invention relates to a pressure activated
two-way slit valve assembly for a catheter. The pressure activated
two-way slit valve assembly includes a first end, a second end, a
wall defining a dumbbell shaped channel that is locatable between
the first and second ends, and a flexible, thin disk that includes
a slit. The flexible, thin disk is disposed within the pressure
activated two-way slit valve assembly such that the slit resides
within the dumbbell shaped channel and is substantially
perpendicular to a longitudinal axis of the pressure activated
two-way slit valve assembly. The slit and the dumbbell shaped
channel of the pressure activated two-way slit valve assembly are
sized to enable the slit to deform in response to a predetermined
pressure differential across the slit to allow fluid to pass
therethrough.
[0006] Embodiments of this aspect of the invention can include the
following features. In one embodiment, the wall of the pressure
activated two-way slit valve assembly further defines connection
ports that are located at the first and second ends. These
connection ports are in fluid communication with the dumbbell
shaped channel. In some embodiments, the first end of the pressure
activated two-way slit valve assembly has a barbed ending for
attaching to a catheter or other similar medical device. In another
embodiment, the second end of the pressure activated two-way slit
valve assembly has a luer ending for attaching to one of a dialysis
machine or an end cap. In some embodiments, the flexible, thin disk
has a straight slit. In other embodiments, the flexible, thin disk
has an H-shaped slit. In another embodiment, the slit of the
flexible, thin disk has a saw-tooth wave shape. In still yet
another embodiment, the pressure activated two-way slit valve
assembly includes a safety rotatable valve key that overrides the
functionality of the pressure activated two-way slit valve assembly
and maintains the pressure activated two-way slit valve assembly in
an open position. In a further embodiment, the safety rotatable
valve key is attached to the second end of the pressure activated
two-way slit valve assembly.
[0007] In another aspect, the invention relates to a medical
device. The medical device includes a catheter including a distal
end, a proximal end, and a housing that defines one or more lumens
that extend between the distal end and the proximal end. The distal
end of the catheter is open whereas the proximal end is attached to
a pressure activated two-way slit valve assembly comprising a first
end, a second end, a wall defining a dumbbell shaped channel that
is locatable between the first and second ends, and a flexible,
thin disk including a slit. The flexible, thin disk is disposed
within the pressure activated two-way slit valve assembly such that
the slit resides within the dumbbell shaped channel and is
substantially perpendicular to a longitudinal axis of the pressure
activated two-way slit valve assembly. The slit and the dumbbell
shaped channel are sized to enable the slit to deform in response
to a predetermined pressure differential across the slit to allow
fluid to pass therethrough.
[0008] Embodiments of this aspect of the invention can include the
following features: In one embodiment, the wall of the pressure
activated two-way slit valve assembly further defines connection
ports that are located at the first and second ends of the pressure
activated two-way slit valve assembly and are in fluid
communication with the dumbbell shaped channel. In another
embodiment, the flexible, thin disk has an H-shaped slit.
Alternatively, in another embodiment, the slit of the flexible,
thin disk has a saw-tooth wave shape. In some embodiments, the
pressure activated two-way slit valve assembly further includes a
safety rotatable valve key that overrides the functionality of the
pressure activated two-way slit valve assembly and maintains the
pressure activated two-way slit valve assembly in an open position.
In a further embodiment, the safety rotatable valve key is attached
to the second end of the pressure activated two-way slit valve
assembly. In still yet another embodiment, the housing of the
catheter is coated with an anti-infective coating to inhibit cell
and bacteria growth.
[0009] In general, in another aspect, the invention relates to a
valved dialysis catheter. The valved dialysis catheter, according
to this aspect of the invention, includes an open-ended single or
multi-lumen catheter including at least one lumen for withdrawing
blood from a patient for dialysis and at least one lumen for
returning blood from a dialysis machine to the patient. Each lumen
of the open-ended multi-lumen catheter includes a pressure
activated two-way slit valve assembly. Each pressure activated
two-way slit valve assembly includes a first end that is connected
to the open-ended single or multi-lumen catheter, a second end that
is connectable to a dialysis machine, a wall extending between a
first end and a second end and defining a dumbbell shaped channel
that is locatable between the first and second ends, and a
flexible, thin disk. The flexible thin disk includes a slit and is
disposed within the pressure activated two-way slit valve assembly
such that the slit resides within the dumbbell shaped channel and
is substantially perpendicular to a longitudinal axis of the
pressure activated two-way slit valve assembly. Both of the slit
and the dumbbell shaped channel are sized to enable the slit to
deform in response to a predetermined pressure differential across
the slit to allow fluid to pass therethrough.
[0010] Embodiments of this aspect of the invention can include the
following features. In one embodiment, the wall of the pressure
activated two-way slit valve assembly further defines connection
ports that are located at the first and second ends of the pressure
activated two-way slit valve assembly. These connection ports are
in fluid communication with the dumbbell shaped channel. In some
embodiments, the first end of the pressure activated two-way slit
valve assembly has a barbed ending connecting the pressure
activated two-way slit valve assembly with the multi-lumen
catheter. In other embodiments, the second end of the pressure
activated two-way slit valve assembly has a luer ending for
attaching to one of a dialysis machine or an end cap. In another
embodiment, the flexible, thin disk has an H-shaped slit.
Alternatively, in a further embodiment, the slit of the flexible,
thin disk has a saw-tooth wave shape. In some embodiments, the
pressure activated two-way slit valve assembly includes a safety
rotatable valve key that overrides the functionality of the
pressure activated two-way slit valve assembly and maintains the
pressure activated two-way slit valve assembly in an open position.
Other embodiments feature a single or multi-lumen catheter with an
anti-infective external surface and further embodiments feature a
single or multi-lumen catheter with an anti-infective internal
surface.
[0011] In general, in another aspect, the invention relates to a
method for preventing air ingestion in a valved catheter and
preventing blood loss from the valved catheter. The method,
according to this aspect of the invention, includes providing the
medical device including the catheter described above, and using
the pressure activated two-way slit valve assembly to prevent air
ingestion through the catheter and into a patient's blood stream
and to prevent blood loss while the valved catheter is not in
use.
[0012] Embodiments of this aspect of the invention can include the
following features. In one embodiment, the predetermined pressure
differential across the slit of the disk within the pressure
activated two-way slit valve is between about 50 cm of water and
about 120 cm of water. In an alternative embodiment, the
predetermined pressure differential is between about 80 cm of water
and 120 cm of water. In other embodiments, the valve is designed to
open at any predetermined pressure selected by a manufacturer.
[0013] The foregoing and other objects, aspects, features, and
advantages of the invention will become more apparent from the
following description and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In the drawings, like reference characters generally refer
to the same parts throughout the different views. Also, the
drawings are not necessarily to scale, emphasis instead generally
being placed upon illustrating the principles of the invention.
[0015] FIG. 1 is schematic view of one embodiment of a pressure
activated two-way slit valve assembly according to the
invention.
[0016] FIG. 2 is an exploded view of the pressure activated two-way
slit valve assembly of FIG. 1.
[0017] FIG. 3 is a cross-sectional view of a first end portion of
the pressure activated two-way slit valve assembly, taken along
line AA of FIG. 1.
[0018] FIG. 4 is a cross-sectional view of a second end portion of
the pressure activated two-way slit valve assembly, taken along
line BB of FIG. 1.
[0019] FIG. 5 is a plan-view of an alternative embodiment of a
lumen extending through the first and second end portions.
[0020] FIG. 6 is another plan-view of another alternative
embodiment of a lumen extending through the first and second end
portions.
[0021] FIG. 7 is a plan-view of a flexible, thin disk that is
disposed within the pressure activated two-way slit valve assembly
of FIG. 1.
[0022] FIG. 8 is a plan-view of another embodiment of a flexible,
thin disk.
[0023] FIG. 9 is a schematic view of one embodiment of a medical
device that includes a catheter and two pressure activated two-way
slit valve assemblies.
[0024] FIG. 10 is a cross-sectional view of a portion of the
catheter, taken along line CC of FIG. 9.
[0025] FIG. 11 is a cross-sectional view of a portion of a tubular
element extending off from the catheter, taken along DD of FIG.
9.
[0026] FIG. 12 is a schematic view of an embodiment of a safety,
rotatable valve key.
[0027] FIG. 13 is a schematic view of the safety, rotatable valve
key of FIG. 12 attached to a second end of the pressure activated
two-way slit valve assembly of FIG. 1.
[0028] FIG. 14 is a schematic view of a valved dialysis catheter
including two pressure activated two-way slit valve assemblies as
used during hemodialysis.
DESCRIPTION
[0029] The kidneys are a pair of organs located near the backbone
that filter and remove waste products from a human being's blood.
Patients who suffer from kidney failure must undergo hemodialysis,
a process in which waste products from the patient's blood are
removed through passing their blood through a dialysis machine.
Generally, these patients require dialysis treatments once every
three days.
[0030] Hemodialysis catheters, which are a type of high flow rate
catheter, are used to transport such a patient's blood to and from
the dialysis machine for treatment. Typically, a portion of the
hemodialysis catheter is implanted within a patient's body while a
reminder of the hemodialysis catheter extends out from the body and
is easily attached to the dialysis machine.
[0031] Other uses for high flow rate catheters can include rapid
infusion of blood and blood products to a patient and infusion of
saline to a dehydrated patient.
[0032] Some of the biggest complaints with conventional high flow
rate catheters are occlusions, thrombus, and catheter-related
infections. Generally, these complications arise due to, at least
in part, poor fluid flow dynamics of the catheter and/or catheter
parts, including, but not limited to, valve assemblies.
[0033] The present invention concerns valve assemblies for high
flow rate catheters having a single lumen or multiple lumens. A
valve assembly, according to the present invention, in combination
with a catheter allows for efficient fluid transport to and/or from
a patient's body. This invention also concerns a valve assembly for
a high flow rate catheter that prevents ingestion of air from
entering the high flow rate catheter and prevents blood loss when
the catheter is not in use.
[0034] Referring to FIG. 1, a pressure activated two-way slit valve
assembly 10 according to the invention includes a first end 12, a
second end 14, and a wall 15 extending from the first end 12 to the
second end 14. The wall 15 can be made from any relatively rigid,
biocompatible, polymer such as, for example, polycarbonate,
polyethylene, or Ultem.RTM. and includes a female housing portion
16 and a male housing portion 18. The male housing portion 18
friction fits within the female housing portion 16, thereby holding
the two portions 16, 18 together. In addition to frictional forces,
an adhesive can be used to secure a bond between the female and
male housing portions 16, 18. Alternatively, the female housing
portion 16 can be thermally, chemically, or ionically bonded to the
male housing portion 18.
[0035] Located at the first and second ends 12, 14 are connection
ports 17 and 19 used to interconnect the pressure activated two-way
slit valve assembly 10 to other medical devices, such as, for
example, catheters, dialysis machines, and end caps. The connection
ports 17, 19 can have barbed or luer endings as shown in FIGS. 1
and 2 to aid in attachment between a medical device and the
pressure activated two-way slit valve assembly 10.
[0036] Disposed within the pressure activated two-way slit valve
assembly 10 is a flexible, thin disk 24, shown in FIG. 2, that is
"sandwiched" between the female housing portion 16 and the male
housing portion 18. The flexible, thin disk 24 is preferably made
from silicone or other similar flexible polymer and includes a slit
26. The flexible, thin disk 24 is positioned within the pressure
activated two-way slit valve assembly 10 such that the slit 26 is
perpendicular to line LL, a longitudinal axis 25 of the pressure
activated two-way slit valve assembly 10. The slit 26 remains in a
closed position as shown in FIG. 2 until a pressure differential
having a predetermined force exists within the pressure activated
two-way slit valve assembly 10. Once the pressure differential
crosses over this predetermined force threshold, the slit 26
separates, thereby allowing blood or fluid to flow
therethrough.
[0037] The pressure activated two-way slit valve assembly 10 also
includes a dumbbell shaped channel 20 that is defined by wall 15
and surrounds the flexible, thin disk 24. As shown in FIGS. 3 and
4, the dumbbell shaped channel 20 is disposed within both of the
female housing portion 16 and the male housing portion 18. The
dumbbell shaped channel 20 has a middle channel portion 27 disposed
between and in fluid communication with two large cross-sectional
area channel portions 28. The middle portion 27 has a smaller
cross-sectional area than the two large cross-sectional area
channel portions 28 and thus, restricts the slit 26 from opening
prematurely (i.e., under conditions where the pressure differential
is below threshold) by decreasing the amount of channel
cross-sectional area in a pressure sensitive region. In some
embodiments, each large cross-sectional area channel portion 28 has
3 times the cross-sectional area as the middle portion 27. This
extra cross-sectional area of the large cross-sectional area
channel portions 28 provides the pressure activated two-way slit
valve assembly 10 with a large amount of fluid transport area, to
maximize fluid flow rates through the pressure activated two-way
slit valve assembly 10 once the slit 26 has cracked open. These
large cross-sectional area channel portions 28 allow the flow rate
through the pressure activated two-way slit valve assembly 10 to
maintain a flow rate of up to 500 ml/min. In some embodiments, the
large cross-sectional area channel portions 28 allow the flow rate
to approach a flow range of about 400 ml/min to 500 ml/min, which
is a greater flow rate range than typically achieved in
conventional valved high flow rate catheters. An advantage of this
greater flow rate range is a decrease in actual catheter use or
treatment time. For example, a hemodialysis catheter having a
greater flow rate range means that there will be a decrease in
dialysis treatment time, which is a greater convenience for both a
dialysis patient and for an attending medical professional.
[0038] The shape of the dumbbell shaped channel 20 can be slightly
modified to produce alternative embodiments of the pressure
activated two-way slit valve assembly 10. As depicted in FIGS. 5
and 6, the perimeter of the large cross-sectional area channel
portion 28 can be extended to form an elongated dumbbell shaped
channel 20b, shown in FIG. 5, or an octagonal dumbbell shaped
channel 20c, as shown in FIG. 6. In some embodiments, the size of
the middle channel portion 27 is minimized such that the two large
cross-sectional area channel portions 28 are separated by a
millimeter or less. Other similar embodiments are also possible as
long as each large cross-sectional area channel portion 28 has a
larger cross-sectional area than the middle portion 27.
[0039] Each of the female and male housing portions 16, 18 can
taper, as depicted in FIG. 1, from an area of greatest diameter
located substantially at connection area 23 to an area of lesser
diameter 21. The dumbbell shaped channel 20 disposed within the
female and male housing portions 16, 18 tapers along with these
portions 16, 18. As the dumbbell shaped channel 20 tapers the shape
of the dumbbell shaped channel 20 gradually transforms from a
dumbbell structure to an oval or circular structure.
[0040] Located within the dumbbell shaped channel 20, between the
female housing portion 16 and the male housing portion 18, is the
flexible, thin disk 24 with slit 26. The slit 26 can be a straight
slit or, in some embodiments, be H-shaped as shown in FIG. 7.
Alternatively, the slit 26 can have a saw-tooth wave shape as shown
in FIG. 8. In any case, the size and shape of the slit 26 and the
size of the dumbbell shaped channel 20 are designed to enable the
slit to deform or crack open when a predetermined pressure
differential exists across the pressure activated two-way slit
valve assembly 10. Generally, the size of the slit 26 and the
dumbbell shaped channel 20 are designed to prevent deformation of
the slit 26 until a pressure differential of at least about 50 cm
of water exists, thereby minimizing accidental openings of slit 26,
which could lead to bleed out or air ingestion. In a preferred
embodiment, the dumbbell shaped channel 20 is designed to prevent
deformation of the slit 26 until a pressure differential within a
range of about 50 cm of water to about 120 cm of water exists. In a
more preferred embodiment, the dumbbell shaped channel is designed
to prevent deformation of the slit until a pressure differential
within a range of about 80 cm of water to about 120 cm of water
exists. It is also important to note that the valve may be designed
to have the slit crack open at any pressure differential preferred
for a particular medical application.
[0041] The two-way slit valve assembly 10 allows fluid to flow
therethrough in either a proximal direction (i.e., from the first
end 12 towards the second end 14) or a distal direction (i.e., from
the second end 14 towards the first end 12). As long as the
pressure differential across the flexible, thin disk 24 is greater
than the threshold, the slit 26 will open automatically and will
allow fluids to pass therethrough in either direction.
[0042] The particular threshold pressure differential is determined
by one or more of the following factors: (1) the thickness of the
flexible, thin disk 24, (2) the size of the slit 26, (3) the
hardness of the material used to form the flexible, thin disk 24,
and (4) the cross-sectional area of the dumbbell shaped channel 20
within each of the female housing portion 16 and the male housing
portion 18. For example, the threshold pressure differential value
of the two-way slit valve assembly 10 can be customized to a
particular value by varying the factors listed above. Thus, if a
particular application of the two-way slit valve assembly 10
required a valve, which could open a very low threshold pressure
differential value, the material and thickness of the flexible,
thin disk 24 and the length of the slit 26 can be selected to
accomplish this usage.
[0043] In some applications of the two-way slit valve assembly 10,
it is important to provide the valve with two different threshold
pressure differential values. That is one particular threshold
pressure differential value for fluids flowing in the proximal
direction and another different threshold pressure differential
value for fluids flowing in the distal direction. Embodiments of
two-way slit valve assemblies 10 used in these applications can
include a dumbbell shaped channel 20 that has a different
cross-sectional area dimension in the female housing portion 16
than in the male housing portion 18, so as create two direction
sensitive threshold pressure differential values.
[0044] The two-way slit valve assembly 10 can be attached to a
catheter having a single lumen or alternatively multiple lumens. By
way of illustration the following example describes usage of the
two-way slit valve assembly in connection with a hemodialysis
catheter (a high flow rate catheter) that has two or more
lumens.
[0045] Referring to FIG. 9, shown is a portion of a hemodialysis
catheter 40 attached to two pressure activated two-way slit valve
assemblies 10a, 10b according to the invention. The hemodialysis
catheter 40 has two distinct lumens 42a, 42b disposed within, as
shown in FIG. 10. One of the lumens 42a provides a path for
waste-filled blood to exit the patient's body, while the opposing
lumen 42b provides a path for blood after dialysis treatment to
return to the body. An adapter 34, shown in FIG. 9 and affixed to
an end of the hemodialysis catheter 40 further separates these two
distinct lumens 42a, 42b into individual tubular elements generally
called extension legs 30.
[0046] Each extension leg 30 has a single lumen 32 disposed within
as shown in FIG. 11. The pair of extension legs 30a, 30b work in
combination. One of the extension legs 30a is in fluid connection
with the lumen 42a that transports waste-filled blood to a dialysis
machine, while the other extension leg 30b is connected to the
lumen 42b that carries treated, clean blood back to the patient.
Each extension leg 30a, 30b is connected to a pressure activated
two-way slit valve assembly 10 that prevents blood from flowing
therethrough when dialysis is not in process. The hemodialysis
catheter 40 in combination with the extension legs 30a, 30b and
pressure-activated slit valve assemblies 10a, 10b can be secured to
a patient's body using a wing clip 36 as shown in FIG. 9.
[0047] The embodiments shown in FIGS. 9 and 10 depict a
hemodialysis catheter 40 having two lumens 42a, 42b. In alternative
embodiments, not shown, the hemodialysis catheter 40 or other high
flow rate catheter can have more than two lumens. In these
embodiments, the additional lumens (i.e., the third, fourth, and so
on) can provide access ports for delivery of liquid medicines or
other fluids to the patient or for collecting blood specimens from
the patient's body. Additional extension legs 30 to connect to the
additional lumens 42 would be needed. Each additional extension leg
30 can be outfitted with one pressure activated two-way slit valve
assembly 10 if desired.
[0048] In some embodiments of this invention, an outer surface 45
of the hemodialysis catheter 40 is coated with an anti-infective
coating, such as an antibiotic (for example, tetracycline or
doxycycline) or an antimicrobial. These anti-infective coating help
prevent the build up of bacteria on the surface of the hemodialysis
catheter 40, thereby helping to minimize the possibility of
complications caused by infection. The hemodialysis catheter can
also have a similar anti-infective coating along a surface 47 of
the lumen 42a, 42b. Likewise, the anti-infective coating present
along the surface 47 helps to prevent infection within the
hemodialysis catheter 40.
[0049] An additional feature that can be incorporated into the
invention is a safety rotatable valve key 50, an embodiment of
which is shown in FIGS. 12 and 13. The safety rotatable valve key
50 can be used force and maintain the slit 26 open to allow for
immediate and constant access to the lumens 42 of the hemodialysis
catheter 40. The safety rotatable valve key 50 includes an inner
tube 52 that can be positioned to extend through the slit 26 when
the safety rotatable valve key 50 is rotated from a first position
to a second position. The safety rotatable valve key 50 can include
a luer ending 54 for attachment to a dialysis machine or an end
cap. In addition, the safety rotatable valve key 50 can also
include a pair of finger knobs 56a, 56b to aid a medical
professional in rotating the safety rotatable valve key 50.
[0050] In operation, a portion of the hemodialysis catheter 40 is
implanted within the patient's body and an open end of the
hemodialysis catheter 40 is located within the patient's blood
stream. To begin hemodialysis, endcaps are removed from the second
end 14 of each pressure activated two-way slit valve assembly 10a,
10b attached to the hemodialysis catheter 40. The second end 14 is
then secured to a dialysis machine 60, shown in FIG. 14, that
supplies sufficient vacuum force to create the required pressure
differential across one the slit 26 of one of the pressure
activated two-way slit valve assemblies 10a. Once the slit 26 has
cracked open, blood will flow from the patient's body through the
hemodialysis catheter 40 to the dialysis machine 60 for treatment
(i.e., removal of waste products from the blood). Simultaneously,
the dialysis machine 60 forces treated blood through another
pressure activated two-way slit valve assembly 10b and into the
hemodialysis catheter to be returned to the patient's body.
[0051] Variations, modifications, and other implementations of what
is described herein will occur to those of ordinary skill in the
art without departing from the spirit and scope of the invention.
The invention is not to be limited only to the preceding
illustrative description.
* * * * *