U.S. patent application number 11/242353 was filed with the patent office on 2006-08-24 for pressure activated iv set.
This patent application is currently assigned to Becton Dickinson and Company. Invention is credited to Chad M. Adams.
Application Number | 20060189946 11/242353 |
Document ID | / |
Family ID | 36603478 |
Filed Date | 2006-08-24 |
United States Patent
Application |
20060189946 |
Kind Code |
A1 |
Adams; Chad M. |
August 24, 2006 |
Pressure activated IV set
Abstract
An IV set includes a drip chamber and a pressure activated
valve. The drip chamber has an operable liquid height and an outlet
orifice. The pressure activated valve is disposed proximate the
outlet orifice of the drip chamber and includes a sealing orifice,
a valve, and a biasing mechanism. The sealing orifice and the
operable liquid height correspond to a head. The biasing mechanism
biases the valve against the sealing orifice with a force less than
the head of the operable liquid height to control the flow of
liquid through the pressure activated valve.
Inventors: |
Adams; Chad M.; (Cedar
Hills, UT) |
Correspondence
Address: |
DAVID W. HIGHET, VP AND CHIEF IP COUNSEL;BECTON, DICKINSON AND COMPANY
1 BECTON DRIVE, MC 110
FRANKLIN LAKES
NJ
07417-1880
US
|
Assignee: |
Becton Dickinson and
Company
|
Family ID: |
36603478 |
Appl. No.: |
11/242353 |
Filed: |
October 3, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60654705 |
Feb 18, 2005 |
|
|
|
Current U.S.
Class: |
604/251 |
Current CPC
Class: |
A61M 5/36 20130101; A61M
39/22 20130101; A61M 1/3626 20130101; A61M 5/16881 20130101; A61M
5/1411 20130101; A61M 39/24 20130101 |
Class at
Publication: |
604/251 |
International
Class: |
A61M 5/14 20060101
A61M005/14 |
Claims
1. An IV set comprising: a drip chamber having an outlet orifice;
and a pressure activated valve disposed proximate the outlet
orifice of the drip chamber, the pressure activated valve
comprising: a sealing orifice; a valve; and a biasing mechanism
that biases the valve against the sealing orifice with a force less
than the pressure head between the sealing orifice and an operable
liquid height in the drip chamber to control the flow of liquid
through the pressure activated valve.
2. The IV set of claim 1, further comprising an air vent connected
to the drip chamber.
3. The IV set of claim 2, wherein the air vent is connected to a
sidewall of the drip chamber proximate to the operable liquid
height.
4. The IV set of claim 1, wherein the biasing mechanism comprises a
spring.
5. The IV set of claim 1, wherein the biasing mechanism comprises a
magnet.
6. The IV set of claim 1, wherein the biasing mechanism comprises a
flexible arm.
7. The IV set of claim 1, further comprising a tube having a first
end and a second end connected to the pressure activated valve,
wherein the IV set further comprises a tube attachment device for
disposing the first end of the tube proximate to the drip
chamber.
8. The IV set of claim 7, wherein the tube attachment device
comprises a clip.
9. The IV set of claim 7, wherein the tube attachment device
comprises a magnet.
10. The IV set of claim 7, wherein the tube attachment device
comprises a hook and loop fastener.
11. The IV set of claim 1, further comprising a tube having a first
end and a second end connected to the pressure activated valve,
wherein the IV set further comprises an end plug removably attached
to the first end of the tube, wherein the end plug comprises an air
vent.
12. An IV set comprising: a drip chamber having an outlet orifice;
and a pressure activated valve disposed proximate the outlet
orifice of the drip chamber, the pressure activated valve
comprising: a sealing orifice; a valve for closing the sealing
orifice; and a means for biasing the valve against the sealing
orifice with a force less than the pressure head between the
sealing orifice and an operable liquid height in the drip chamber
to control the flow of liquid through the pressure activated
valve.
13. The IV set of claim 12, further comprising an air vent
connected to the drip chamber.
14. The IV set of claim 13, wherein the air vent is attached to a
sidewall of the drip chamber proximate to the operable liquid
height.
15. The IV set of claim 12, further comprising a tube having a
first end and a second end connected to the pressure activated
valve, wherein the IV set further comprises a tube attachment
device for disposing the first end of the tube proximate to the
drip chamber.
16. The IV set of claim 12, further comprising a tube having a
first end and a second end connected to the pressure activated
valve, wherein the IV set further comprises an end plug removably
attached to the first end of the tube, wherein the end plug
comprises an air vent.
17. A method for priming an IV set, the method comprising:
connecting the IV set to a source of a liquid, wherein the IV set
comprises a drip chamber having an outlet orifice; and a pressure
activated valve disposed proximate the outlet orifice of the drip
chamber, the pressure activated valve comprising a sealing orifice,
a valve for closing the sealing orifice, and a biasing mechanism
that biases the valve against the sealing orifice with a force less
than the pressure head between the sealing orifice and an operable
liquid height in the drip chamber to control the flow of liquid
through the pressure activated valve; drawing the liquid into the
drip chamber; and moving the valve from the sealing orifice to
permit the liquid to exit the pressure activated valve when the
head of the liquid in the drip chamber exceeds the force of the
biasing mechanism.
18. The method of claim 17, wherein the IV set further comprises a
tube connected to the pressure activated valve having an end remote
from the pressure activated valve and a tube attachment device,
wherein the method further comprises the step of disposing the end
of the tube proximate the drip chamber.
19. The method of claim 17, wherein the IV set further comprises an
air vent, the method further comprising the step of venting air
from the drip chamber.
20. The method of claim 19, wherein the air vent is disposed
proximate the operable liquid height of the drip chamber, the
method further comprising the step of preventing air from exiting
the air vent when the height of the liquid within the drip chamber
reaches the height of the air vent.
21. The method of claim 17, further comprising the step of moving
the valve against the sealing orifice to prevent the flow of liquid
through the pressure activated valve when head of the liquid within
the drip chamber is less than force of the biasing mechanism.
Description
CROSS-REFERENCED RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/654,705, filed Feb. 18, 2005.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to tubing sets used in the
administration of liquids to a patient that are commonly referred
to as intravascular ("IV") sets and more particularly concerns
pressure activated IV sets. An IV set according to the invention is
used broadly herein to include tubing sets used in the arterial,
intravenous, intravascular, peritoneal, and non-vascular
administration of liquid into a patient. Of course, one of skill in
the art may use an IV set to administer liquids to other locations
within a patient's body than those listed.
[0003] Generally, an IV set includes tubing for connecting a
patient to a source of liquid. Additionally, an IV set may include
a drip chamber connected to the tubing, which is used by a nurse,
physician, or other attendant to determine the flow rate of liquid
through the IV set. The drip chamber is shaped to encourage liquid
entering the drip chamber to form droplets that fall toward the
bottom of the drip chamber. By counting each droplet over a period
of time, the flow rate of liquid is able to be discerned.
[0004] When an IV set is prepared for use with a patient, a clamp
on the tubing is manually closed to prevent liquid from moving from
the drip chamber through the tubing. The IV set may then be
attached to a source of liquid, such as an IV bag or bottle. Once
attached, the drip chamber is squeezed to force air out of the drip
chamber which is replaced by liquid from the IV bag or bottle.
[0005] Generally, enough air is removed to permit the drip chamber
to be filled about 1/3 to about 1/2 full of liquid, which may be
deep enough to prevent air in the drip chamber from being sucked
into the tubing. Additionally, this liquid height is also low
enough that each droplet may be efficiently counted by an
attendant. To obtain this liquid height, the drip chamber may need
to be squeezed repeatedly and closely monitored to obtain an
operable liquid height.
[0006] Once the height of the liquid in the drip chamber is
sufficient for operation of the IV set, the clamp is manually
opened to allow liquid to flow through and replace air in the
tubing of the IV set. However, as the liquid flows through the
tubing air is frequently trapped in the tubing. For example, the
flow of the liquid through the tubing of the IV set may be
turbulent and can entrap air as the boundary layer between the
liquid and the tubing is sheared. Additionally, if the liquid level
is too low, a bubble ladder may form as air is intermittently
sucked from the drip chamber into the tubing.
[0007] Once the liquid is distributed throughout the tubing of the
IV set, it is a generally good practice to remove entrapped air
from the IV set. While this concern is critical when accessing
allowed to enter a patient's blood stream while receiving the
intravenous administration of liquids, the air bubbles can form an
air embolism and cause serious injury to a patient.
[0008] To remove air bubbles from the IV set, liquid from the IV
bag or bottle is allowed to flow through the tubing while an
attendant taps the tubing to encourage the air bubbles out the end
of the IV set. As the liquid is allowed to flow out of the IV set
to clear air bubbles from the tubing, the liquid is generally
allowed to flow into a waste basket or other receptacle. During
this procedure the end of the tubing may contact the waste basket
or be touched by the attendant and thus, become contaminated.
[0009] Once the entrapped air is removed, the IV set is ready to be
connected to a patient. This process of preparing an IV set for
connection to a patient is commonly referred to as "priming" an IV
set.
[0010] If there is a delay between priming the IV set and
connecting it to a patient, a solid cap may be attached to the end
of the IV set to completely close and protect the end of the IV set
from contamination. The cap may then be removed when the patient is
ready to have the IV set connected.
[0011] Because of the constant supervision and many different steps
that may be required to prime an IV set, the priming of an IV set
may be a time consuming process. Additionally, the priming of an IV
set can lead to the contamination of the IV set by inadvertently
touching a sterile end of the IV set. Furthermore, the attention
and time used to prime of an IV set could have been used to perform
other tasks that may be valuable to the patient.
[0012] An additional concern may arise when the IV bag or bottle
begins to run dry. Specifically, when the IV bag or bottle is
empty, air may be pulled through the IV set and into the patient.
To prevent air from entering a patient through an IV set, air
bubble sensors may be connected to the IV set that alert an
attendant that air has entered the IV set and is moving toward the
patient. However, these sensors merely alert the attendant that
action is required and do not act to prevent the air from entering
the patient. Additionally, these sensors may be expensive and may
require additional training to use.
[0013] Alternatively, a floating seal may be positioned in the drip
chamber of an IV set. As the liquid level drops, the floating seal
may be seated against the outlet orifice of the drip properly,
which may allow air to enter a patient. Alternatively, the floating
seal may be inadvertently sucked onto the outlet orifice of the
drip chamber before the IV bag or bottle has run dry, preventing
the patient from receiving needed liquid and medication.
[0014] Thus, an IV set may require frequent supervision by an
attendant to avoid these problems. Furthermore, because air may
enter the tubing in both of these options for preventing air from
entering a patient through the IV set, the IV set may need to be
debubbled as each used IV bag or bottle is replaced.
[0015] Accordingly, a need exists for an IV set that is
self-priming, and which does not require constant attention and
supervision. A need also exists for an IV set that is self-leveling
to ensure that an operable liquid height is maintained in the drip
chamber. Additionally, a need exists for an IV set that prevents
air from entering the tubing when the IV bag or bottle runs
dry.
BRIEF SUMMARY OF THE INVENTION
[0016] The apparatus of the present invention has been developed in
response to the present state of the art, and in particular, in
response to the problems and needs in the art that have not been
fully solved by currently available IV sets. Thus, the present
invention provides a pressure activated IV set for use in
intravenous administration of liquids that may be self-priming and
self-leveling.
[0017] In accordance with the invention as embodied and broadly
described herein in the preferred embodiment, an IV set is
provided. The IV set may include a coupling for connecting it to a
source of liquid. The coupling may be a Luer fitting, a spike, or
other coupling known in the art.
[0018] A drip chamber may be connected to the coupling for
determining the flow rate of liquid through the IV set. Typically,
IV sets are gravity fed so that the drip chamber may include an
inlet orifice disposed in a top end and an outlet orifice disposed
in a bottom end of the drip chamber. A sidewall may extend between
the top end and the bottom end.
[0019] A pressure activated valve may be connected to the outlet
orifice of the drip chamber that may control the flow of liquid
through the outlet orifice of the drip chamber. In some
configurations, the pressure activated valve may abut or be
integrally formed with the drip chamber. The pressure activated
valve may operate so that when an operable liquid height in the
drip chamber is reached, the pressure activated valve opens to
permit liquid to exit the outlet orifice of the drip chamber.
Additionally, when the liquid height falls below the operable
liquid height, the pressure activated valve closes to prevent
liquid from exiting the outlet orifice of the drip chamber.
[0020] The pressure activated valve may include a sealing orifice
that may be positioned inline with the outlet orifice of the drip
chamber and may be integrally formed with the drip chamber. The
sealing orifice may be a hole surrounded by a relatively sharp
shoulder against which a valve may be seated to close the sealing
orifice. Alternatively, the sealing orifice may include a beveled
shoulder to encourage a tight seal with the valve.
[0021] The valve may have a shape similar to the shape of the
sealing orifice to facilitate closing the sealing orifice. For
example, the valve may have a rounded or beveled engagement surface
for abutting and closing the sealing orifice. In some
configurations, the valve may also include a flexible engagement
surface that facilitates the sealing of the valve against the
sealing orifice. Thus, the valve may include an elastomeric surface
for providing a tight seal against the sealing orifice.
[0022] The pressure activated valve may also include a means for
biasing and positioning the valve against the sealing orifice. The
biasing means may be a biasing mechanism that stores potential
energy such as a spring, a magnet, or a flexible arm. For example,
the biasing mechanism may be a coil spring attached to the valve.
The coil spring is compressed so that it applies a force to the
valve against the sealing orifice. Alternatively, the biasing
mechanism may be a magnet positioned to repel a second magnet
attached to the valve so that the magnet of the biasing mechanism
forces the valve against the sealing orifice.
[0023] In other configurations, the biasing mechanism may be a
compliant arm attached to the valve that may be deflected to bias
the valve against the sealing orifice. Alternatively, the biasing
mechanism may include a torsion spring or leaf spring connected to
a rigid arm attached to the valve that biases the valve against the
sealing orifice. The biasing mechanism may also be an elastomeric
material that when elastically compressed acts as a spring, which
biases the valve against the sealing orifice.
[0024] The biasing mechanism may bias the valve against the sealing
orifice with a force approximately equal or less than the pressure
head between the sealing orifice and an operable liquid height in
the drip chamber to control the flow of liquid through the pressure
activated valve. Thus, as the pressure of the liquid above the
valve exceeds the force of the biasing mechanism and/or any
buoyancy forces associated with the valve, the valve is forced away
from the sealing orifice to open the pressure activated valve. The
weight of the valve and biasing mechanism may also be considered in
determining the proper biasing force of the biasing mechanism. For
simplicity, the force of the biasing mechanism generally includes
any buoyancy forces associated with the biasing mechanism and the
valve.
[0025] The operable liquid height is the height of liquid from the
sealing orifice to a height within the drip chamber. More
specifically, the operable liquid height within the drip chamber is
such that if the drip chamber is held vertically and the IV set is
filled with liquid to the operable liquid height, the liquid would
exert a force against the valve greater than the force that the
biasing mechanism biases the valve against the sealing orifice and
any buoyancy forces associated with the valve and biasing
mechanism.
[0026] Additionally, the operable liquid height may be
approximately the height of liquid at which the drip chamber is
normally filled when the IV set is ready to be connected to a
patient. Thus, the operable liquid height may range from about 1/4
to about 2/3 the height of the drip chamber. Preferably, the
operable liquid height may range from about 1/3 to about 1/2 the
height of the drip chamber.
[0027] When priming the IV set, liquid may be unable to enter the
drip chamber from a source of liquid as the pressure within the
drip chamber increases. To release this pressure, the drip chamber
may include an air vent. The air vent may be designed to prevent
liquid from passing through the vent, while allowing air to exit
the drip chamber. The air vent may also permit air to only exit and
not to enter the drip chamber. Additionally, the air vent may be
connected to a sidewall of the drip chamber proximate to the
operable liquid height. This helps to maintain a desirable liquid
level within the drip chamber, by preventing additional air from
exiting the drip chamber once liquid reaches the air vent.
[0028] Referring back to the IV set, the IV set may include a tube
having a first end and a second end that may be connected to the
pressure activated valve. The first end may include a coupling,
such as a Luer fitting to facilitate connecting the IV set to a
patient.
[0029] An end plug may be connected to the coupling of the first
end of the tube. The end plug may include an air vent designed to
permit air to exit and prevent liquid from exiting. The end plug
may help to prevent contamination of the IV set and may be removed
and discarded when the IV set is to be connected to a patient.
[0030] The air vent of the end plug may be used to slow the rate at
which air exits the IV set. By slowing the exit of air from the IV
set, liquid flowing through the IV set is also slowed. Slow flowing
liquid is less likely to entrap air in the IV set, which reduces
the need to remove air bubbles from the IV set.
[0031] Additionally, the IV set may include a means for disposing
the first end of the tube proximate the drip chamber. The disposing
means may be used to further slow the flow of liquid through the IV
set by using hydrostatic pressure. The disposing means may also be
used to prevent contamination of the remote end of the tube and to
prevent liquid from inadvertently exiting the IV set.
[0032] The disposing means may be a tube attachment device. The
tube attachment device may be integrally formed with the drip
chamber, the pressure activated valve, or another part of the IV
set. Of course, the tube attachment device may be formed
separately. In some configurations, the tube attachment device may
include a clip for positioning the remote end of the tube near the
drip chamber, and more preferably, near the operable liquid height
of the drip chamber. The tube attachment device may also include a
magnet for magnetically positioning and securing the remote end of
the tube near the drip chamber.
[0033] Alternatively, the tube attachment device may include a hook
and loop fastener. For example, a piece of fabric having a
plurality of hooks may be attached proximate the remote end of the
tube and a piece of fabric having a plurality of corresponding
loops may be attached to the drip chamber, the pressure activated
valve, an opposite end of the tube, or another component of the IV
set. Additionally, the tube attachment device may include an
adhesive for positioning and securing the remote end of the tube
near the drip chamber.
[0034] A method for priming the IV set disclosed above may include
the steps of connecting the IV set to a source of a liquid, drawing
the liquid into the drip chamber, and moving the valve from the
sealing orifice to permit the liquid to exit the pressure activated
valve when the head of the liquid in the drip chamber exceeds the
force of the biasing mechanism. All of these steps may be
accomplished automatically by the IV set of the invention except
for connecting the IV set to a source of a liquid, which can result
in considerable time savings for a physician, nurse, or attendant
priming the IV set for use with a patient. Of course, the step of
drawing liquid into the drip chamber may be facilitated by the
nurse or attendant by squeezing the drip chamber to induce a vacuum
into the drip chamber.
[0035] The method may also include the steps of disposing the
remote end of the tube proximate to the drip chamber and
preferably, near the operable liquid height of the drip chamber. In
configurations where the IV set includes an air vent, the method
also include the steps of venting air from the drip chamber and
preventing air from exiting the air vent when the height of the
liquid within the drip chamber reaches the height of the air vent.
To prevent air from reaching a patient when the IV bag or bottle is
empty, the method may also include the step of moving the valve
against the sealing orifice to prevent the flow of liquid through
the pressure activated valve when the head of the liquid within the
drip chamber is less than the force of the biasing mechanism.
[0036] These and other features and advantages of the present
invention will become more fully apparent from the following
description and appended claims, or may be learned by the practice
of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0037] In order that the manner in which the above-recited and
other features and advantages of the invention are obtained will be
readily understood, a more particular description of the invention
briefly described above will be rendered by reference to specific
embodiments thereof which are illustrated in the appended drawings.
Understanding that these drawings depict only typical embodiments
of the invention and are not therefore to be considered to be
limiting of its scope, the invention will be described and
explained with additional specificity and detail through the use of
the accompanying drawings in which:
[0038] FIG. 1 is a perspective view of an IV set according to the
invention connected to an IV bag;
[0039] FIG. 2 is a partially cut away side view of another IV set
according to the invention connected to an IV bottle;
[0040] FIG. 3 is a partially cut away side view of an alternative
IV set according to the invention;
[0041] FIG. 4 is a partially cut away side view of yet another IV
set according to the invention; and
[0042] FIG. 5 is a partially cut away side view of yet another IV
set according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The presently preferred embodiments of the present invention
will be best understood by reference to the drawings, wherein like
parts are designated by like numerals throughout. It will be
readily understood that the components of the present invention, as
generally described and illustrated in the figures herein, could be
arranged and designed in a wide variety of different
configurations. Thus, the following more detailed description of
the embodiments of the IV set of the present invention, as
represented in FIGS. 1 through 5, is not intended to limit the
scope of the invention, as claimed, but is merely representative of
presently preferred embodiments of the invention.
[0044] Referring to FIG. 1, a perspective view illustrates an IV
set 10 connected to a source of liquid 12, such as an IV bag 14
containing a liquid 16, by a coupling 20. The coupling 20 may be a
spike 22 that is used to puncture the IV bag 14 and access the
liquid 16.
[0045] The coupling 20 of the IV set 10 may be connected directly
to a drip chamber 24. More specifically, the coupling 20 may be
connected to a top end 26 of the drip chamber 24. The top end 26 of
the drip chamber 24 may include an inlet orifice 28 that receives
liquid 16 from the IV bag 14 through the coupling 20.
[0046] The drip chamber 24 may include a sidewall 30 that extends
between the top end 26 and a bottom end 32 having an outlet orifice
34. The sidewall 30 may include an air vent 36 that permits air to
exit the drip chamber 24 while preventing liquid 16 from exiting
the drip chamber 24 through the outlet orifice 34.
[0047] The air vent 36 prevents pressure from building in the drip
chamber 24 with each droplet of liquid 16 that enters from the IV
bag 14 when the flow of liquid 16 through the outlet orifice 34 is
blocked. Without the air vent 36, pressure builds within the drip
chamber 24 which may cause the flow of liquid 16 to slow until
liquid 16 no longer enters the drip chamber 24. Thus, the air vent
36 may be positioned in the sidewall 30 to encourage the liquid 16
to fill to a desired height in the drip chamber 24. Specifically,
the liquid 16 is encouraged to enter the drip chamber 24 up to the
height of the air vent 36 in the side wall 30. Once the height of
the liquid 16 reaches and blocks the air vent 36, the flow of
liquid 16 slows and may stop entering the drip chamber 24 until
flow through the outlet orifice 34 is unblocked.
[0048] To control the flow of liquid 16 through the outlet orifice
34, the outlet orifice 34 may be connected to a pressure activated
valve 38. More specifically, the pressure activated valve 38 is
disposed so that a sealing orifice 40 is in liquid communication
with the outlet orifice 34 of the drip chamber 24. To block the
flow of liquid 16 through the outlet orifice 34, a valve 42 may be
moved against the sealing orifice 40 by a biasing mechanism 44.
[0049] The valve 42 may have a rounded engagement surface 46 that
engages and abuts a sharp shoulder 48 of the sealing orifice 40.
The engagement surface 46 may be flexible to provide a tight seal
against the sealing orifice 40. For example, the valve 42 may be
made of an elastomeric material that flexes to seal against the
shoulder 48 of the sealing orifice 40.
[0050] The pressure activated valve 38 opens and closes in response
to the height of liquid 16 being greater than or less than an
operable liquid height 50, respectively. Specifically, the biasing
mechanism 44 biases the valve 42 against the sealing orifice 40
with a force equal to about the head between the sealing orifice 40
and an operable liquid height 50 in the drip chamber 24 when the
drip chamber 24 is held vertically. Thus, as the height of liquid
16 in the drip chamber 24 exceeds the operable liquid height 50,
the pressure of the liquid 16 exceeds the biasing force of the
biasing mechanism 44 to move the valve 42 away from the sealing
orifice 40 and permit the flow of liquid 16 through the outlet
orifice 34 of the drip chamber 24 and the pressure activated valve
38. When the height of liquid 16 in the drip chamber 24 is less
than the operable liquid height 50, the pressure of the liquid 16
is less than the biasing force of the biasing mechanism 44.
Therefore, the valve 42 engages and seals against the sealing
orifice 40 preventing the flow of liquid 16 through the outlet
orifice 34 of the drip chamber 24 and the pressure activated valve
38.
[0051] The biasing mechanism 44 in this configuration of the
invention may include a spring 51. When the pressure activated
valve 38 is assembled, the spring 51 may be attached to the valve
42 and compressed to store potential energy and bias the valve 42
against the sealing orifice 40.
[0052] Alternatively, the biasing mechanism 44 may include a
portion of the valve 42 that is buoyant. Additionally, the spring
51 may tend to pull the valve 42 away from the sealing orifice 40.
However, in this configuration, the biasing mechanism 44 is able to
bias the valve 42 against the sealing orifice 40 because the
buoyancy force of the portion of the valve 42 is greater than the
force of the spring 51.
[0053] The pressure activated valve 38 may be connected to a tube
52 for conveying the flow of liquid 16 from the drip chamber 24.
Specifically, the tube 52 may have a first end 54 and a second end
56 that may be connected to the pressure activated valve 38.
[0054] The first end 54 may have a connector 58 for connecting the
IV set 10 to a patient (not shown), another IV set (not shown) in a
piggy back arrangement, or another device known in the art. For
example, the connector 58 may be connected to an end plug 60 that
may be solid or include an air vent 62 that permits air to exit the
tube 52 but prevents liquid 16 from exiting the first end 54 of the
tube 52. The air vent 62 may also be designed to restrict the flow
of air out of the first end 54 of the tube 52 in order to slow the
flow of liquid 16 that moves through the IV set 10 when the IV set
10 is primed. The connector 58 may be Luer fitting for a threaded
or press fit connection or another connector known in the art.
[0055] The IV set 10 may also include a tube attachment device 64
for disposing the second end 56 of the tube 52 proximate to the
drip chamber 24 during priming of the IV set 10. Disposing the
second end 56 of the tube 52 proximate to the drip chamber 24
during priming slows the flow of liquid 16 through the IV set 10
via the hydrostatic pressure of the liquid 16. As shown, the tube
attachment device 64 may be integrally formed with the pressure
activated valve 38 and may include a clip 66 for removable
attachment of the tube 52 to the tube attachment device 64.
[0056] Referring to FIG. 2, a partially cut away side view
illustrates another IV set 100 that may be connected to a source of
liquid 102, such as an IV bottle 104 containing a liquid 106. the
IV set 100 includes many features similar to the IV set 10 of FIG
1. For brevity similar features may not be discussed in detail.
[0057] As shown, a pressure activated valve 110 is open because the
height of the liquid 106 in a drip chamber 112 exceeds the operable
liquid height 114 of the drip chamber 112. Thus, the liquid 106 is
able to flow from the drip chamber 112 through the pressure
activated valve 110 to a tube 116.
[0058] The pressure activated valve 110 may include a housing 120
that defines a sealing orifice 122 in liquid communication with an
outlet orifice 124 of the drip chamber 112. The sealing orifice 122
may include a beveled shoulder 126 that may be engaged by a valve
128 to close the sealing orifice 122. The valve 128 may have an
engagement surface 130 that is reciprocally shaped to the shape of
the sealing orifice 122 to facilitate engaging and closing the
sealing orifice 122. Thus, the engagement surface 130 may be
beveled.
[0059] The housing 120 further defines a flow chamber 132 that
extends from the sealing orifice 122 to an exit orifice 134 that
may be connected to the tube 116. The housing 120 may also include
a support feature 136 for positioning a biasing mechanism 138
within the flow chamber 132. Specifically, the support feature 136
may extend into the flow chamber 132 to position the biasing
mechanism 138 in line with the sealing orifice 122.
[0060] The biasing mechanism 138 may include a base magnet 140 that
repels a valve magnet 142. The valve magnet 142 is a part of the
valve 128 and attached to the engagement surface 130. The pressure
activated valve 110 may be opened when the pressure of the liquid
106 exceeds the magnetic force between the opposed base magnet 140
and the valve magnet 142.
[0061] The IV set 100 may also include a tube attachment device 144
that may include two clips 146 for gripping a first end 148 and a
second end 150 of the tube 116. The tube attachment device 144 may
be used to position the first end 148 of the tube 116 near the drip
chamber 112.
[0062] FIG. 3 is a partially cut away side view showing an
alternative IV set 200. The IV set 200 includes many features
similar to the IV set 10 of FIG. 1. For brevity, similar features
may not be discussed in detail.
[0063] As shown, a pressure activated valve 202 is open because the
height of the liquid 204 in the drip chamber 206 exceeds the
operable liquid height 208. Because the pressure activated valve
202 is open, liquid 204 may flow from a drip chamber 206 and pass
through the pressure
[0064] The pressure activated valve 202 may have a housing 211 that
includes a sealing orifice 212 that is in liquid communication with
an outlet orifice 214 of the drip chamber 206. The sealing orifice
212 may have a curved shoulder 216 that mates with a curved
engagement surface 218 of a valve 220 of the pressure activated
valve 202. The valve 220 is positioned and supported by a biasing
mechanism 222.
[0065] The biasing mechanism 222 comprises arms 224 that may be
attached to the housing 211. The arms 224 may be flexible so that
the arms 224 bias the valve 220 toward the sealing orifice 212. The
flexible arms 224 may be similar to a spring that stores potential
energy as they flex in response to the head between the sealing
orifice 212 and the height of the liquid 204 in the drip chamber
206, such that the valve 220 may move away from the sealing orifice
212 when the height of the liquid 204 exceeds the operable liquid
height 226 of the drip chamber 206.
[0066] The IV set 200 may also include a tube attachment device
230. The tube attachment device may include a hook and loop
fastener 232 for disposing a first end 234 of the tube 210
proximate to the drip chamber 206. As shown, a fabric strip of
hooks 236 may be attached to the drip chamber 206 and a fabric
strip of loops 238 may be connected to the first end 234 of the
tube 210 to facilitate the positioning of the first end 234 of the
tube 210 near the drip chamber 206.
[0067] FIG. 4 is a partially cut away side view illustrating yet
another IV set 300. The IV set 300 includes many features similar
to the IV set 10 of FIG. 1. For brevity, similar features may not
be discussed in detail.
[0068] As shown in FIG. 4, an outlet orifice 302 of a drip chamber
304 is connected to a pressure activated valve 306. The pressure
activated valve 306 is closed, because the height of a liquid 308
in the drip chamber 304 has not equaled or exceeded the operable
liquid height 310. Therefore, the liquid 308 is unable to flow
through the outlet orifice 302 of the drip chamber 304.
[0069] The pressure activated valve 306 includes a housing 312 that
includes a sealing orifice 314 that has a sharp shoulder 316. An
engagement surface 318 of a valve 320 may engage the shoulder 316
and close the sealing orifice 314.
[0070] As shown, the valve 320 may be integrally formed with a
biasing mechanism 322. The valve 320 and biasing mechanism 322 may
be an arm of elastomeric material that extends between the sealing
orifice 314 and a support feature 324 of the housing 312. In some
configurations, the valve 320 and biasing mechanism 322 may be made
of a closed cell, foamed material or a solid material.
Additionally, the valve 320 and biasing mechanism 322 may be made
of an elastomer or other material known in the art.
[0071] As the height of the liquid 308 increases in the drip
chamber 304, the biasing mechanism 322 compresses under the
pressure of the liquid 308 in the drip chamber. When the liquid 308
is about equal to or exceeds the operable liquid height 310, the
engagement surface 318 disengages from the sealing orifice 314 and
the liquid 308 is able to flow through the outlet orifice 302 of
the drip chamber 304 and the housing 312 of the pressure activated
valve 306. Once the height of the liquid 308 falls below the
operable liquid height 310, the biasing mechanism 322 expands to
force the engagement surface 318 against the shoulder 316 of the
sealing orifice 314 and close the pressure activated valve 306.
[0072] The IV set 300 may also include a tube attachment device 324
for disposing a first end 326 of a tube 328 near the drip chamber
304. A second end 330 of the tube 328 may be connected to the
pressure activated valve 306. The tube attachment device 324 may
include a first magnet 332 attached to the drip chamber 304 and a
second magnet 334 attached to the first end 326 of the tube 328.
Thus, to position the first end 326 of the tube 328, the first
magnet 332 may be brought near the second magnet 334.
[0073] In reference to FIG. 5, a partially cut away side view
illustrates a different IV set 400 according to the invention. The
IV set 400 is similar in many ways to the IV set 300 of FIG. 4.
Thus, for brevity, only the differences will de discussed detail.
As shown, the IV set 400 includes a pressure activated valve 402
disposed between a drip chamber 404 and the tubing 406 of the IV
set 400. Specifically, an outlet orifice 408 of the drip chamber
404 is connected to a sealing orifice 410 of a housing 412 of the
pressure activated valve 402. The housing 412 of the pressure
activated valve 402 also includes an exit orifice 410 that is
connected to the tubing 406.
[0074] The housing 412 contains a structure 414 that includes the
biasing mechanism 416 and valve 418 of the pressure activated valve
402. The housing 412 includes a wall 420 that is disposed at an
angle 422 to the sealing orifice 410. The angle 422 of the wall 420
guides the valve 418 as it moves within the housing 412 to seat
against the sealing orifice 410 and close the pressure activated
valve 402.
[0075] The biasing mechanism 416 of the structure 414 is total
volume of the structure 114 having an average density less than
water. As shown in a partially cut away view, the average density
less than water may be obtained by including one or more air
bubbles 424 within the structure 414, by making the structure 414
out of a material 426 whose density is less than the density of
water, or a combination of these methods. The valve 418 is the
outer surface 428 of the structure 414 that contacts and seats
against the sealing orifice 410 to close the pressure activated
valve 402.
[0076] The pressure activated valve 402 operates by initially
allowing fluid to pass through the pressure activated valve 402. As
the housing 412 fills with liquid, the structure 414 floats upward
to seat against the sealing orifice 410 and close the pressure
activated valve 402. Thus, the valve 418 is held against the
sealing orifice 410 by the buoyancy force of the biasing mechanism
416.
[0077] Once the liquid level in the drip chamber 404 reaches an
operable fluid height 430, the valve 418 is forced away from the
sealing orifice 410 to open the pressure activated valve 402.
Specifically, the pressure head between sealing orifice 410 and the
operable fluid height 430 is greater than the buoyancy force of the
biasing mechanism 416, which opens the pressure activated valve
402.
[0078] In summary, an IV set according to the invention may include
a pressure activated valve that opens when an operable liquid
height is reached and closes when the liquid in the drip chamber
falls below the operable liquid height. The operable liquid height
is the height of liquid in the drip chamber that exerts pressure on
the valve about equal to the force exerted by the biasing mechanism
on the valve against the sealing orifice.
[0079] The pressure activated valve may be used to automatically
prime the IV set, by controlling the flow of liquid through the IV
set. For example, once the IV set is connected to a source of
liquid, the drip chamber may be filled to an operable liquid
height, when the liquid begins to flow from the drip chamber
through the pressure activated valve and through the tubing of the
IV set.
[0080] Additionally, the pressure activated valve permits the IV
set to be uncoupled from a first source of liquid and be recoupled
to a second source of liquid without having to reprime the IV set.
More specifically the pressure activated valve closes once the
liquid falls below the operable liquid height which prevents air
from entering the tubing of the IV set through the drip chamber.
Once reconnected to a source of liquid, the drip chamber fills with
liquid to exceed the operable liquid height and the pressure
activated reopens to allow liquid to flow.
[0081] The components of the pressure activated valve may be made
from a variety of materials, such as metals, plastics, and
ceramics. The components may be made by extrusion, injection
molding, stamping, blow molding, machining, and other manufacturing
processes known in the art.
[0082] The flow of the liquid may be retarded by using an air
filter and positioning the first end of the tube near the drip
chamber. A slow moving liquid may be less likely to entrap air in
the IV set. Thus, less air may be entrapped and less time needed to
remove air bubbles from the IV set before it may be connected to a
patient.
[0083] The present invention may be embodied in other specific
forms without departing from its structures, methods, or other
essential characteristics as broadly described herein and claimed
hereinafter. The described embodiments are to be considered in all
respects only as illustrative, and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims,
rather than by the foregoing description. All changes that come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *