U.S. patent application number 10/328483 was filed with the patent office on 2003-06-05 for suspension device and method.
This patent application is currently assigned to MALLINCKRODT INC.. Invention is credited to Hughes, Michael Scott.
Application Number | 20030105423 10/328483 |
Document ID | / |
Family ID | 23228516 |
Filed Date | 2003-06-05 |
United States Patent
Application |
20030105423 |
Kind Code |
A1 |
Hughes, Michael Scott |
June 5, 2003 |
Suspension device and method
Abstract
A device and method for providing a suspended agent such as a
contrast agent without mechanical resuspension. A volume of agent
(12) is divided into sub-volumes in a network (8) of tubes (18),
cells (42), sponges (44), grooves (48), etc. A propellant fluid
(16) flows through the network (8) to release the suspended agent
(12). The network (8) may be internal to a container (10) for the
propellant fluid (16). Alternatively, the network (8) may be
adjacent an exit port (24) of a container (10) for the propellant
fluid (16), or may be in-line between a propellant fluid container
(10) and a patient. The invention reduces sedimentation of agents
into one or a few aggregates and eliminates a mechanical mixing
step. The invention thus provides a uniformly suspended agent,
improving patient health and safety and increasing cost and time
savings.
Inventors: |
Hughes, Michael Scott;
(Glencoe, MO) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER
441 VINE STREET
CINCINNATI
OH
45202
US
|
Assignee: |
MALLINCKRODT INC.
St. Louis
MO
|
Family ID: |
23228516 |
Appl. No.: |
10/328483 |
Filed: |
December 23, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10328483 |
Dec 23, 2002 |
|
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|
09316315 |
May 21, 1999 |
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Current U.S.
Class: |
604/27 |
Current CPC
Class: |
A61M 5/1452 20130101;
A61M 5/007 20130101; A61M 5/1409 20130101 |
Class at
Publication: |
604/27 |
International
Class: |
A61M 001/00 |
Claims
What is claimed is:
1. A method for administering an agent to a patient comprising
providing a tubular network containing subvolumes of an agent out
of suspension, the network containing ports for inflow and outflow
of a propellant fluid to release the agent from the network,
connecting the network to a vessel of a patient, providing the
propellant fluid to the inflow port to suspend the agent and
administering the suspended agent to the patient.
2. The method of claim 1 wherein the network is within a
syringe.
3. The method of claim 2 wherein the syringe contains the
propellant fluid.
4. The method of claim 1 wherein the agent administered is a
contrast agent.
5. The method of claim 1 wherein the tubular network is configured
randomly, in parallel, coiled, or helically.
6. A method for administering a volume of an agent to a patient
comprising dividing said volume into a plurality of subvolumes of
an agent out of suspension in a network, providing a propellant
fluid under pressure to said network at an inflow port to contact
and suspend the subvolumes of agent, and administering the
suspended agent to a patient from an outflow port of the network to
a patient connector.
7. The method of claim 6 further comprising containing said
propellant fluid in a container with the network internal to the
container.
8. The method of claim 6 wherein said container is a dose delivery
container.
9. The method of claim 6 wherein said container is a packaging
container.
10. The method of claim 8 wherein said dose delivery container is
selected from the group consisting of a manual syringe, a power
syringe and a bag.
11. The method of claim 6 further comprising containing said
propellant fluid in a container with the network external to the
container.
12. The method of claim 11 wherein said container has an exit port
and said network is operably connected adjacent said exit port.
13. The method of claim 11 wherein said network is operably
connected in-line between said container and said patient
connector.
14. The method of claim 11 wherein said agent is released by
injecting said propellant fluid into an entry port of said
container.
15. A method of administering a volume of an agent to a patient
comprising containing subvolumes of an agent out of suspension in a
tubular network capable of insertion within a syringe and
connection to a vessel of a patient, providing a propellant fluid
to said network, pressurizing said propellant fluid to initiate
flow of said fluid to resuspend said agent, and administering said
suspended agent to said patient vessel through a patient
connector.
16. The method of claim 12 wherein the agent is a contrast
agent.
17. The method of claim 12 wherein pressure is provided by a
mechanical source.
18. The method of claim 12 wherein pressure is provided by a manual
source.
19. The method of claim 12 wherein the network is within a
syringe.
20. A method for administering an agent to a patient comprising
providing the agent in a tubular network in an interior of a
container having an exit port capable of coupling to a patient
connector and defining an interior space containing a propellant
fluid, the network having a single passageway containing subvolumes
of the agent, an outflow port in fluid communication with the exit
port, and an inflow port opening into the interior space, and
flowing the propellant fluid into the inflow port and through the
passageway to release subvolumes of the agent from the outflow port
through the exit port to the patient connector to administer the
agent to the patient.
21. The method of claim 20 wherein the container is a syringe.
22. The method of claim 20 wherein the patient is administered a
contrast agent.
23. The method of claim 20 wherein the patient is imaged by a
method selected from the group consisting of computed tomography,
magnetic resonance imaging, ultrasound, and X-ray.
24. A method for administering an agent to a patient comprising
providing subvolumes of an agent in a helical tube within a syringe
having a side wall defining an interior space, an exit port
connected to a patient connector, and a plunger positioned in the
interior space and having a sealing engagement with the side wall,
the interior space between the plunger and the exit port containing
a propellant fluid for the agent and the plunger being movable in
the interior space toward the exit port, the tube defining a
continuously open and uninterrupted fluid passageway within the
interior space of the syringe and located between the plunger and
the exit port, the fluid passageway having an outflow port in fluid
communication with the exit port of the syringe and an inflow port
opening into the interior space, providing pressure to the plunger
to flow propellent fluid through the fluid passageway to contact
the agent for flow from the outflow port and exit port and into a
patient connector.
Description
[0001] This application is a divisional of U.S. application Ser.
No. 09/316,315 filed May 21, 1999, now pending and expressly
incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a device and method of using the
device for providing a suspended volume of an agent without
additional mixing.
BACKGROUND
[0003] Agents that do not persist in a suspended state and sediment
must be resuspended prior to use. One example of an agent that must
be resuspended prior to use is a pharmaceutical colloid, such as a
contrast agent that is injected into a patient to enhance an
imaging procedure. Contrast agents are used in various types of
imaging including x-ray, magnetic resonance imaging (MRI), computed
tomography (CT) and ultrasound (US). A contrast agent that comes
out of suspension must be resuspended before placing the desired
volume to be dosed into a delivery container such as a syringe. If
there is a delay before the dose is injected into a patient, for
example while preparing the patient or equipment, or if the
infusion is extended, the agent must again be suspended before or
during administration.
[0004] Resuspension of contrast agent requires mechanical
manipulations, for example, removing a filled syringe positioned in
an injector and remixing its contents. Additional remixing steps
may delay a critical infusion time or, if remixing is omitted, the
entire imaging procedure may have to be repeated due to suboptimal
contrast obtained. Duplicate procedures not only put patients at
increased risk and inconvenience, but are also cost- and
time-inefficient. Even if the need to resuspend a single bolus
injection is not prohibitive for a given procedure, repeated bolus
injections or long term continuous infusions can become problematic
due to agent coming out of suspension during administration.
[0005] The loss of suspension for a contrast agent at any point in
a delivery system to a patient, such as in a syringe and/or in the
connecting tubing, severely limits the duration of continuous
infusions or the time between intermittent injections. The need to
initially resuspend the colloid or other type of agent, and to
further suspend if the agent is not used shortly after
resuspension, requires either time-consuming effort and vigilance
by the user or the use of mechanical mixing devices. In any case,
the need to resuspend an agent poses an additional step and a
possible source of error in an imaging procedure.
SUMMARY OF THE INVENTION
[0006] The invention is directed to a device that provides a
suspended agent without additional mechanical mixing. The device
divides a total volume of a sedimenting agent into a network of
sub-volumes and has prots for an inflow and outflow of a propellant
fluid to releases the sub-volumes of agent from the device. In one
embodiment, the device is located within a container in which the
agent is packaged, such as a vial or bottle, or in a container in
which the agent is dosed, such as a syringe or bag, or in a
container containing the propellant fluid. In another embodiment,
the device is located external to a container for the propellant
fluid. In this embodiment, the device may be operably attached to
an exit port of the propellant fluid container. Alternatively, in
this embodiment, the device may be positioned in-line at any point
with lines that connect the propellant fluid container with a
patient connector. The device is comprised of a network of
sub-volumes that may take the form of one or more tubes, cells
and/or sponges, and that may assume any configuration such as a
parallel, stairstep, helical, random and/or coiled configuration.
The network may be retained in a network holder.
[0007] The invention is also directed to a suspension device for a
volume of an agent in which a container for the propellant fluid
has a network of grooves that are integral with the container and
that retain a sub-volume of the agent within the grooves. The
container has a plug that occupies an internal volume of the
container and the grooves are either integral with an internal wall
of the container, or are integral with an external wall of the
plug. In either embodiment, the plug diverts the propellant fluid
flow to a variable extent from the center of the container to the
periphery of the container, thus diverting fluid flow through the
grooves. The grooves may further contain substantially
perpendicular channels at regular intervals to allow uniform
filling of the grooves with the agent.
[0008] The invention is also directed to a method of providing a
volume of suspended agent to a patient. The method includes
dividing the volume of agent into contained sub-volumes, storing
the sub-volumes in a network for containing sub-volumes of the
agent and providing a propellant fluid under pressure to eject the
sub-volumes of agent through the network and into a patient. The
propellant fluid may be housed in a container in which the network
is also located. Alternatively, the network may be external to the
propellant fluid container, with the network positioned either
in-line between a source of propellant fluid and a patient, or
adjacent an exit port of a propellant fluid container.
[0009] The invention is also directed to a suspension device for a
folume of an imaging contrast agent. A network contains a plurality
of sub-volumes of the agent and has inflow and outflow ports for
propellant fluid. The device may also have a container and network
holder external to the container.
[0010] The objectives and other advantages of this invention will
be further understood with reference to the following drawings and
detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 is a cross-sectional view of a syringe container with
an internal tubular network.
[0012] FIG. 1A is a view similar to FIG. 1 of an alternate
embodiment of the invention.
[0013] FIG. 2 is a cross-sectional view of a syringe container with
an external tubular network operably attached to a propellant fluid
container exit port.
[0014] FIG. 3 is an elevational view of an in-line device.
[0015] FIGS. 4A, 4B and 4C are various network embodiments and
configurations.
[0016] FIG. 5 is a cross-sectional view of a syringe container
having an integral network.
[0017] FIG. 6 is a cross-sectional view of an integral network with
channels.
DETAILED DESCRIPTION
[0018] The device of the invention sub-divides a desired volume of
an agent to suspend the agent without mechanical mixing.
Resuspension is caused by viscous fluid flow through the network of
sub-volumes. As used herein, the device is comprised of a network
of structures for containing sub-volumes of the agent, with the
entire volume of agent contained in the network component
sub-volumes. As will be described, the device may be located in the
same container that contains propellant fluid to eject the agent
from the network (container package embodiment). Alternatively, the
device may be located adjacent an exit port of a propellant fluid
container (add-on embodiment), or may be positioned in-line at any
point in a fluid path between the propellant fluid container and
the ultimate deposit site such as a patient (in-line embodiment).
As used herein, a propellant fluid is one that is used to eject the
agent from the network of tubes, cells, etc. As used herein, a
network is defined as a collection of structures which contain the
entire desired volume of agent in sub-volumes, and hence increase
the surface area of the agent over which the propellant fluid must
flow, in the device. In one embodiment, the network has a common
exit port, and agent sub-volumes are ejected from the network at a
substantially equal rate. The network may encompass tubes, cells,
sponges, etc. and is not limited by volume or configuration.
[0019] The device sub-divides a volume of an agent to prevent it
from settling or sedimenting into one or a few dense aggregates
without the need for mechanical mixing or suspending prior to use,
and thus reduces or eliminates the problem of remixing or
resuspending an agent that has come out of suspension prior to use.
Use may be either preparing an injection dose by transferring the
desired volume of agent from a package to a dosing container such
as syringe, or injecting the dosing volume of agent into a patient.
This problem may occur with contrast agents, either while in their
package or portioned in a container such as a syringe for injecting
into a patient about to undergo an imaging procedure. The invention
solves the problem by subdividing the volume of the agent to
prevent separation or aggregation of the agent from the suspending
liquid.
[0020] Dividing a uniformly suspended contrast agent or other agent
into a network of sub-volumes rather than a single large volume
inhibits the particles from either floating or precipitating into
one or more larger masses or aggregates. The invention thus reduces
or obviates the need for mixing before or during a process, such as
an infusion process. This increases the quality, safety, and cost-
and time- efficiencies of the process.
[0021] With reference to FIG. 1, a network 8a containing divided
sub-volumes of an agent 12 is internal to a container 10 for
propellant fluid 16. The container 10 may be a syringe 14 or other
types of containers which include but are not limited to vials,
bags having flexible or semi-flexible walls, bottles of either
glass or plastic, etc. The agent 12 contained in the network 8a is
ejected from the container 10 as propellant fluid 16 flows through
the network 8a and displaces the agent 12. The propellant fluid 16
is any viscous fluid (liquid or gas) that is biocompatible. The
propellant fluid may be a diluent for the agent 12 such as normal
saline, water, buffer, etc. The propellant fluid 16 may also be a
contrast agent that is different from the agent 12 injected for the
imminent imaging procedure.
[0022] The network 8a may be any structure that serves to contain a
sub-volume of the desired total volume of an agent 12 in a unit
area. The network 8a may be contained in a network holder 22. The
network 8a may be tubes 18 which, as used herein, encompass
tubules, microtubules, channels, or other types of hollow cylinders
that convey a fluid or that function as a passageway, whereby a
volume of agent 12 is divided into sub-volumes of any size. There
are numerous configurations of the tubes 18 that can be used to
sub-divide the volume of agent 12. These include, but are not
limited to, a single long tube 18 as best shown in FIG. 1 or a
collection of tubes 18a as shown in FIG. 1A. The tubes 18 may be in
any configuration, such as one or more coils or helices, an angular
or stairstep configuration, and/or even random configurations. A
collection of tubes 18 may similarly be one or more coils or
helices, an angular or stairstep configuration, and/or even random
configurations, or may be arranged in a parallel configuration
(FIG. 1A). The geometries and configurations of the network 8 may
be combined in either regular or random configurations. While FIGS.
1 and 1A show tubes 18 positioned in a syringe 14 without any
accompanying support, other configurations are contemplated. For
example, the tubes 18 may be positioned within a network holder 22
(FIGS. 2 and 3), or may be supported or held in a syringe 14 or
network holder 22 by a fixture such as 24 (shown in phantom lines
in FIG. 1) which may extend for part of or all of the length of the
network 8.
[0023] With reference to FIG. 2, a dose delivery container 10 that
is a syringe 14 is shown with a network holder 22 containing the
network 8 external to the syringe 14. The network 8c is packaged
within a network holder 22, which may be any container in which the
network is housed or retained and may be made of any biocompatable
material. The network holder 22 containing the network 8c may be
separable from the syringe 14 or other container 10 and attached to
an exit port 24 of the syringe 14 or container 10. The network
holder 22 for the network 8c may also be manufactured as part of
the container 10, which may be useful as a pre-packaged embodiment
of the invention. In a non-pre-packaged embodiment, the network
holder 22 may be attached to an exit port 24 using, for example,
connectors 26 such as luer fittings. The exit port 24 of the
syringe 14 may be fitted with luer fittings, such as Luer-Lok.RTM.
caps (Becton-Dickinson), or may have luer fittings such as metal,
brass or glass luer tips attached. As previously described, a
support or fixture 30 for the tubes 28 may be used, and the support
30 and tubes 28 may be contained in a network holder 22. As one
alternative, the support 30 and tubes 28 may be contained directly
in the container 10. As another alternative, the tubes 28 in a
network holder 22 may be unsupported as shown in FIG. 2.
[0024] While FIG. 2 illustrates a network holder 22 which is
attached to a syringe 14, other embodiments are contemplated. With
reference to FIG. 3, the network (not shown) contained in a network
holder 22 is shown in an in-line embodiment. The network holder 22
is fashioned with connectors 26 at both an inflow port 32 and an
outflow port 34. Tubing is connected to connectors 26 to carry
propellant fluid 16 from a syringe to holder 22 and from holder 22
to a patient. The connectors 26 may be the same or different at the
inflow 32 and outflow 34 ports and may be any type such as luer
fittings, as previously described. Network holder 22 and the
network inside may be configured symmetrically, so that the
orientation of the network holder 22 in an in-flow embodiment need
not be a concern; i.e., there is no back-to-front or front-to-back
limitation. Agent 12 can be removed from the network within the
network holder 22 upon pressure from a propellant fluid 16.
[0025] A network 8 that is internal to a container 10 such as a
syringe 14 need not be housed in a network holder 22. As seen in
FIGS. 1 and 1A, the network 8a, 8b of tubes 18 or other structures
may be positioned directly within the barrel 36 of the syringe 14.
In an alternative embodiment, the network 8 that is internal to a
syringe 14 or other container 10 may also be housed in a network
holder 22. In either embodiment, the barrel 36 of the syringe 14
may contain a propellant fluid 16 that, upon initiation of flow,
provides pressure to release or eject the agent 12 from the network
8. The propellant fluid 16 need not be pre-filled in the barrel 36
of the syringe 14, but instead may be added to the barrel 36 of the
syringe 14.
[0026] The sub-dividing volume structure of tubes 18 in the network
8 may assume a variety of geometries and configurations. As shown
in FIGS. 1A, 2, 4A, 4B and 4C, the tubes 18 may be straight,
coiled, helical, in random filaments 38, in an angular or stairstep
(not shown) configuration, or may have other configurations. All of
these alternatives are appropriate for use in any of the
illustrated embodiments. The sub-dividing network 8 need not
encompass tubes 18 at all; all shown in FIGS. 4A, 4B and 4C, the
network 8d, 8e and 8f respectively, may be a series of discrete
cells 42 (see FIG. 4B), or may have a sponge 44 type of structure
(see FIG. 4A). In a cell 42 structure, the agent 12 is retained in
or on discreet cells 42. In a sponge 44 structure, the agent 12 is
either absorbed in or adsorbed on the sponge 44, rather than
contained within tubes 18 or cells 42. A cell 42 or sponge 44
structure may also be used effectively in a network holder 22
separate from a syringe 14. In any embodiment, the network 8 may be
configured so that there is a non-uniform direction for all
sub-volumes, that is, there is no single upward, downward or
lateral direction for all sub-volumes.
[0027] With reference to FIG. 5, a network 8g that is integral with
the container 10 is shown. In this embodiment, the network 8g is
fabricated as grooves or channels 48 that are etched or otherwise
manufactured within the container 10 itself. For example, a syringe
14 may have a cylindrical plug 46 disposed in the barrel 36, where
the plug 46 has parallel or spiral grooves 48 in its outer surface.
The grooves 48 contain the agent 12 between the syringe 14 inner
wall 50 and barrel 36. As shown in FIG. 6, the grooves 48 may
contain substantially perpendicular channels 60 at one or more
regularly spaced intervals. The channels 60 permit rapid and
uniform filling of the network 8 with agent 12 added into one side
of a container 10 when the other side of the container 10 is
sealed. In another embodiment, the syringe 14 has a cylindrical
plug 46 disposed in the barrel 36 as previously described, where
the inner wall 50 of the syringe 14 has parallel or spiral grooves
in its structure. The grooved structures 48 may also be used in a
separate network holder 22. In these embodiments, the grooved
structure 48 comprises the network 8 which sub-divides the volume
of agent 12. It will thus be appreciated that the network 8 may
assume a variety of forms and configurations whereby a volume of
agent 12 can be sub-divided into smaller volumes with increased
surface area of the agent 12 over which the propellant fluid 16
flows to reduce sedimentation.
[0028] The network 8, whether in the form of tubes 18, cells 42 or
sponges 44, may be made of any biocompatable material that can
withstand sterilization and is inert with respect to the agent 12,
the propellant fluid 16, and the container 10. Examples of such
materials for a tubular 18 network include biocompatable tubing
such as polyethylene, polypropylene, silicon, rubber, etc., for
example, Tygon.RTM. tubing (halogenated vinyl plastic, Norton
Plastics). Tubes 18 used in kidney dialysis devices, such as
cellulose tubes 18 having a nominal diameter of 200 .mu.m, may also
be used in the invention. In a network 8e having cells or voids,
the cells 42 may be produced by incomplete fusion of pieces of
fusable material such as thermoplastics or metals. The cells 42 may
be made of Delrin.TM., polycarbonate such as Lexan.TM.,
polyethylene, polypropylene, silicon, rubber, etc. In a network 8d
having a sponge 44 structure, the sponge 44 may be made of porous
Delrin.TM., porpous polycarbonate such as Lexan.TM., porous
polyethylene, porous polypropylene, porous silicon, porous rubber,
etc.
[0029] The size and volume of the network 8, container 10, and
network holder 22 may vary, depending upon a number of factors.
These factors include the volume of agent 12, the size of the
container 10, the duration of the imaging or other procedure to be
performed, etc. There is neither a maximum nor a minimum volume for
the network 8, container 10, or network holder 22, and an
exponential range of volumes is contemplated by the invention. For
embodiments in which the network 8 is internal or integral with the
container 10, however, the volume of agent 12 contained within the
network 8 is at most one-half the volume of propellant fluid 16 in
the container 10. This ensures that substantially all the agent 12
will be released from the network 8 by the flow of propellant fluid
16. For example, volumes of contrast agent 12 injected for enhanced
ultrasound imaging may range from 1 ml to about 10 ml. As an
example, a 3 ml volume of agent would require using about a 10 ml
syringe 14, with the tubular 18 or other structure of the network 8
containing 3 ml agent 12 and the remaining volume of the syringe 14
containing at least 3 ml, and more typically 4-5 ml, of propellant
fluid 16. A 3 ml volume of agent 12 may be sub-divided in a syringe
14 having ten threads or grooves 48 per inch, with the threads or
grooves 48 one millimeter deep, each thread or groove 48 containing
about 0.3 ml agent 12.
[0030] The container 10 and/or network holder 22 may be
manufactured having the network 8 preloaded with a uniformly mixed
suspension of agent 12 such as a pharmaceutical colloid. The
container 10 and/or network holder 22 may have both an entry port
54 and an exit port 56 with appropriate fittings 26 such as luer
locks for connection to standard tubing or catheters, as is known
to one skilled in the art (FIG. 3). To eject the agent 12 in the
network 8 from the exit port 56 of the container 10 or network
holder 22 and into the patient through a patient connector line,
propellant fluid 16 may be injected into the entry port 54 or,
alternatively, pressure may be applied to the propellant fluid 16
already in the container 10. The container 10 may also have a
single exit port 56 and a plunger 58, with liquid 60 in the
opposite end, to permit use as a prefilled syringe (FIG. 1).
[0031] The specific location, position and configuration of the
network 8 may depend upon an intended use. For example, an agent
containing a gas other than air should be housed in a container 10
that has been purged of air. A container 10 made of glass may be
rendered air-tight more easily than a plastic syringe, and thus is
preferable for this agent. Likewise, a network 8 that is internal
rather than external is preferred for use with an agent that
contains a gas other than air. This allows the propellant fluid 16
to be purged of air and become saturated with the agent-containing
gas, maintaining a substantially anaerobic environment prior to
injection.
[0032] One advantage of the invention is that it eliminates the
need for resuspension of agents 12 that may come out of suspension,
either in their original container 10 or in a dose delivery
container such as a syringe 14. Conventional containers 10 require
mechanical devices or manipulations to maintain colloids such as a
contrast agent 12 in suspension. By eliminating the need for prior
resuspension of the agent 12 for single-bolus injection, the device
and method of the present invention provides a competitive
advantage for injectable agents 12. In accordance with the
principles of the present invention, a syringe 14 having a network
8 containing agent 12 can remain resuspendable for more than five
months.
[0033] Maintaining the agent 12 in a substantially fully
resuspendable state assures consistent quality and reduced
sensitivity to user technique. The agent 12 may be shipped already
prepackaged in the network 8. This arrangement has the potential to
reduce susceptibility of agents, such as microbubble preparations,
to mechanical vibration and shock which may decrease the integrity
of the agent 12. Dividing the volume of agent 12 into sub-volumes
also allows it to be more quickly preheated to a desired
temperature, facilitating the efficiency of the entire imaging
procedure.
[0034] Another advantage of the invention is that the colloid or
other agent 12 may be released, ejected or expelled from the exit
port 56 of the container 10 by injecting a propellant fluid 16.
This precludes the need to draw the pharmaceutical or contrast
agent 12 into a syringe 14 for injection, and provides similar
advantages as enjoyed by pre-filled syringes.
[0035] Still another advantage of the invention is that, in those
embodiments such as FIGS. 2 and 3 where network 8 is external to
the syringe 14, the exit port 56 of the dose delivery container 10
or network holder 22 may be connected to a short angiocatheter (not
shown) that is very close to a venous or arterial puncture site in
a patient. This arrangement prevents loss of suspension of agent 12
that would occur inside a longer catheter, and permits use of a
manual or power syringe located a substantial distance away from
the patient, while preventing the need for the agent 12 to maintain
resuspendable in the manual or power syringe 14 and connecting
tubing. Instead, the manual or power syringe and tubing need only
contain a non-colloidal fluid that does not require mixing or
resuspending during long injection times.
[0036] A further advantage of the invention is realized with an
optional built-in plunger 58 in the syringe 14. A built-in plunger
58 permits use of the device as a manual syringe 14 or with a
small, battery-operated power injector at the end of a very short
angiocatheter. In either case, the filled syringe 14 could be
located very close to a venous or arterial puncture site,
precluding the need to maintain the agent 12 resuspended in a long
catheter for infusion into a patient. This embodiment also
precludes the need for a fluid-filled syringe 14 connected to the
entry port 54 of the dose delivery container 10 in order to eject
the agent 12 from the exit port 56 of the dose delivery container
10.
[0037] It should be understood that the embodiments of the present
invention shown and described in the specification are exemplary
embodiments contemplated by the inventor and are not limiting in
any way. For example, the invention is not limited to use in the
clinical area and may be used in research applications, as well as
in other industries where uniformly suspended agents are needed,
such as the food and beverage industries. In such cases, for
example, the propellant fluids 16 may also include oils, epoxy
resins, sugars, etc., depending upon the application. Therefore,
various changes, modifications or alterations to these embodiments
may be made or resorted to without departing from the spirit of the
invention and the scope of the following claims.
* * * * *