U.S. patent application number 10/624797 was filed with the patent office on 2004-03-18 for infusion systems and methods for introducing fluids into the body within a desired temperature range.
This patent application is currently assigned to Radiant Medical Inc.. Invention is credited to Ginsburg, Robert.
Application Number | 20040054325 10/624797 |
Document ID | / |
Family ID | 25141442 |
Filed Date | 2004-03-18 |
United States Patent
Application |
20040054325 |
Kind Code |
A1 |
Ginsburg, Robert |
March 18, 2004 |
Infusion systems and methods for introducing fluids into the body
within a desired temperature range
Abstract
The invention provides systems and methods for infusing a fluid
into a patient. In one exemplary embodiment, a system comprises a
volume of fluid and a temperature altering device in close
proximity to the volume of fluid. The temperature altering device
is employed to heat or cool the volume of fluid to a desired
temperature. A positive pressure device is provided to place the
volume of fluid under positive pressure while at the desired
temperature. A transfer member is further provided to transfer at
least some of the fluid into the patient while at the desired
temperature.
Inventors: |
Ginsburg, Robert; (Greenwood
Village, CO) |
Correspondence
Address: |
Robert D. Buyan
STOUT, UXA, BUYAN & MULLINS, LLP
Suite #310
4 Venture
Irvine
CA
92618
US
|
Assignee: |
Radiant Medical Inc.
|
Family ID: |
25141442 |
Appl. No.: |
10/624797 |
Filed: |
July 22, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10624797 |
Jul 22, 2003 |
|
|
|
09444532 |
Nov 22, 1999 |
|
|
|
6620130 |
|
|
|
|
09444532 |
Nov 22, 1999 |
|
|
|
09187761 |
Nov 6, 1998 |
|
|
|
5989238 |
|
|
|
|
09187761 |
Nov 6, 1998 |
|
|
|
08787425 |
Jan 22, 1997 |
|
|
|
5879329 |
|
|
|
|
Current U.S.
Class: |
604/113 ; 606/20;
606/27 |
Current CPC
Class: |
A61M 5/445 20130101 |
Class at
Publication: |
604/113 ;
606/020; 606/027 |
International
Class: |
A61F 007/12 |
Claims
What is claimed is:
1. A system for infusing a fluid into a patient, the system
comprising: a volume of fluid; a temperature altering device in
close proximity to the volume of fluid to heat or cool the volume
of fluid to a desired temperature; a positive pressure device to
place the volume of fluid under positive pressure while at the
desired temperature; and a transfer member to transfer at least
some of the fluid into the patient while at the desired
temperature.
2. A system as in claim 1, wherein the temperature altering device
comprises a heater, and wherein the desired temperature is within
the range from about 36.degree. C. to about 42.degree. C.
3. A system as in claim 1, wherein the temperature altering device
comprises a cooler, and wherein the desired temperature is within
the range from about 0.degree. C. to about 35.degree. C.
4. A system as in claim 1, further comprising a reservoir for
holding the volume of fluid, wherein the transfer member is
operably connected to the reservoir, and further comprising a flow
regulator to regulate the flow of the fluid from the reservoir and
into the transfer member.
5. A system as in claim 4, wherein the flow regulator comprises a
controller which regulates the application of pressure from the
positive pressure device.
6. A system as in claim 5, wherein the flow regulator regulates
both the rate and the volume of fluid removed from the
reservoir.
7. A system as in claim 4, wherein the reservoir comprises a
compressible bag.
8. A system as in claim 1, wherein the transfer member comprises a
length of tubing.
9. A system as in claim 1, further comprising a controller to
monitor the temperature of the volume of fluid and to control
actuation of the temperature altering device.
10. A system as in claim 1, wherein the temperature altering device
comprises a housing having inner walls which define a chamber,
wherein the fluid is held within the chamber, and wherein the
housing includes temperature altering elements to heat or cool the
inner walls of the housing to alter the temperature of the
fluid.
11. A system as in claim 10, wherein the temperature altering
elements are selected from the group of elements consisting of
electrical resistors, chemicals, frozen liquids, heated liquids,
heated gases, radio frequency electrodes, and thermoelectric
crystals.
12. A system as in claim 1, wherein the positive pressure device
comprises a plate and a compressor for moving the plate against the
volume of fluid to compress the fluid.
13. A system as in claim 11, wherein the compressor is selected
from the group of compressors consisting of springs, hydraulics,
and solenoids.
14. A system as in claim 1, wherein the positive pressure device
comprises a bladder and a pressure source to expand the bladder
against the volume of fluid.
15. A system as in claim 1, wherein the volume of fluid is selected
from the group of fluids consisting of blood, saline solutions,
drugs, and solutes.
16. A method for infusing a fluid into a patient, the method
comprising: providing a volume of liquid which is at an initial
temperature; altering the temperature of the fluid until the fluid
is at a desired temperature; and pressurizing the fluid while at
the desired temperature to introduce the fluid into the patient at
the desired temperature.
17. A method as in claim 16, further comprising regulating the
pressure applied to the fluid to introduce the fluid into the
patient at a predetermined rate and volume.
18. A method as in claim 16, further comprising flowing the
pressurized liquid through a tube which is intravenously inserted
to the patient to introduce the fluid into the patient.
19. A method as in claim 16, further comprising heating the fluid
to the desired temperature which is within the range from about
36.degree. C. to about 42.degree. C.
20. A method as in claim 16, further comprising cooling the fluid
to the desired temperature which is within the range from about
0.degree. C. to about 35.degree. C.
21. A method as in claim 16, wherein the temperature altering step
comprises placing the volume of fluid into a housing having inner
walls which define and chamber and heating or cooling the inner
walls to alter the temperature of the fluid.
22. A method as in claim 16, wherein the pressurizing step
comprises compressing the volume of liquid with a plate.
23. A method as in claim 16, wherein the pressurizing step
comprises inflating a bladder which presses against the volume of
fluid.
24. A method as in claim 16, wherein the volume of fluid is
selected from the group of fluids consisting of blood, saline
solutions, drugs, and solutes.
25. A method as in claim 16, wherein the volume of fluid is held
within a compressible bag, and wherein the temperature of the fluid
is altered while within the bag.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to the introduction
of various fluids into a patient, and more particularly to the
alteration of the temperature of the fluids prior to their
introduction so that the fluids are within a desired temperature
range when introduced. In one particular aspect, the fluids are
pressurized to facilitate their introduction into the patient at a
desired rate and volume, thereby allowing the fluids to be
introduced without relying on the assistance of gravity.
[0002] Various medical procedures rely on the introduction of
different fluids into the body, often directly into the blood
stream. In many cases, it is desirable to have such fluids
introduced while the temperature of the fluids are within a desired
range. For example, as described in copending U.S. application Ser.
No. 08/769,931, filed Dec. 19, 1996 (Attorney Docket No. 19766707),
the complete disclosure of which is herein incorporated by
reference, heated or cooled fluids may be introduced into a patient
suffering from hypothermia or hyperthermia, or for neuro
protection. Copending U.S. application Ser. No. 08/769,931, filed
Dec. 19, 1996, describes various catheter embodiments which heat or
cool a fluid while the fluid is within the patient. In this manner,
a fluid may be heated to a desired temperature to raise the
patient's core body temperature and thereby reduce or eliminate the
symptoms of hypothermia. Alternatively, such catheter embodiments
may be employed to cool the fluid while within the patient to lower
the patient's core body temperature. Cooling of the fluid while
within the patient may also be employed by such catheter
embodiments to cool a specific region of tissue prior to performing
a surgical procedure.
[0003] In many cases the treatment of a patient requires urgent
medical attention and may therefore limit the types of equipment
that may be used for treatment. For instance, in cases where the
introduction of fluids into the patient is a prescribed treatment,
the fluids must be introduced into the patient as quickly as
possible. In such cases, it would therefore be desirable to provide
a portable system that could be used in the field or in an
ambulance to rapidly infuse various fluids which are within a
desired temperature range into the patient.
[0004] Many existing fluid introduction systems rely on a gravity
feed system where the fluid is held within a compressible
structure, such as an IV bag. However, such gravity feed systems
are often inconvenient in cases where urgent treatment is required,
such as in the field or in tight spaces where elevation of the IV
bag is impossible, e.g. in an ambulance. For example, without
proper elevation, it is difficult to regulate the rate and volume
of fluid introduction.
[0005] Another drawback of such gravity feed systems is the
difficulty in regulating the temperature of the fluid within the IV
bag. Hence, with such systems it is difficult to ensure the fluid
is at the proper temperature when introduced into the patient.
[0006] Hence, for these and other reasons, it would be desirable to
provide systems and methods which would place a fluid within a
desired temperature range prior to its introduction into a patient.
Such systems and methods should also be conducive to urgent care
settings which require mobility, manipulation in tight spaces and
rapid preparation. Such systems and methods should also be able to
precisely control the rate and volume of fluid introduction into
the patient. Further, in some cases it would be desirable if the
systems and methods were able to place the fluids within the
desired temperature range while the fluids are within conventional
containers, such as IV bags.
SUMMARY OF THE INVENTION
[0007] The invention provides systems and methods for infusing
fluids into a patient. According to the invention, the fluids may
be infused into the patient in a variety of ways, including
intraveneously, intra-arterially, peritoneally (intra-abdominally),
and the like. In one exemplary embodiment, a system is provided
comprising a volume of fluid, and a temperature altering device in
close proximity to the volume of the fluid to heat or cool the
fluid to a desired temperature. A positive pressure device is
further provided to place the volume of fluid under positive
pressure while at the desired temperature. A transfer member is
provided to transfer at least some of the fluid into the patient
while the fluid is at the desired temperature.
[0008] In one aspect of the system, the temperature altering device
comprises a heater to heat the fluid to a temperature which is
within the range from about 36.degree. C. to about 42.degree. C.
Alternatively, the temperature altering device may comprise a
cooler to cool the fluid to a temperature within the range from
about 0.degree. C. to about 35.degree. C.
[0009] In another aspect, the system further includes a reservoir,
such as a compressible bag, for holding the volume of fluid. The
transfer member is operably connected to the reservoir, and a flow
regulator is provided to regulate the flow of fluid from the
reservoir and into the transfer member. The flow regulator
preferably comprises a controller which regulate the application of
pressure from the positive pressure device. In one particular
aspect, the flow regulator will preferably regulate both the rate
and volume of the fluid removed from the reservoir.
[0010] In still another aspect, the transfer member comprises a
length of tubing to which an end dwelling device, such as a needle,
catheter, sheath, or the like may be attached to infuse the fluid
into the patient. In still another aspect, a controller is provided
to monitor the temperature of the volume of fluid and to control
actuation of the temperature altering device.
[0011] In one particular aspect, the temperature altering device
comprises a housing having inner walls which define a chamber. The
fluid is held within the chamber, and the housing includes
temperature altering elements to heat or cool the inner walls of
the housing to alter the temperature of the fluid. A variety of
temperature altering elements may be provided to either heat or
cool the inner walls such as electrical resistors, chemicals,
frozen liquids, heated liquids, heated gases, radio frequency
electrodes, thermoelectric crystals, and the like.
[0012] In another particular aspect, the positive pressure device
comprises a plate and a compressor for moving the plate against the
volume of fluid to compress the fluid. Exemplary compressors for
moving the plate include springs, hydraulics, solenoids, and the
like. Alternatively, the positive pressure device may comprise a
bladder and a pressure source to expand the bladder against the
volume of fluid.
[0013] The system may be employed to introduce a wide variety of
fluids into the patient. Such fluids may include, for example,
blood, saline solutions, drugs, solutes and the like.
[0014] The invention further provides an exemplary method for
infusing a fluid into a patient. According to the method, a volume
of fluid is provided and is at an initial temperature. The
temperature of the fluid is altered until the fluid is at a desired
temperature. While at the desired temperature, the fluid is
pressurized to introduce the fluid into the patient at the desired
temperature.
[0015] The pressure applied to the fluid will preferably be
regulated so that the fluid is introduced into the patient at a
predetermined rate and volume. In one exemplary aspect, the
pressurized liquid is flowed through a tube which is intravenously
inserted into the patient to introduce the fluid directly into the
patient's blood stream.
[0016] In a further aspect, the fluid is heated to the desired
temperature which is within the range from about 36.degree. C. to
about 42.degree. C. Alternatively, the fluid may be cooled to the
desired temperature which is in the range from about 0.degree. C.
to about 35.degree. C. In one particularly preferable aspect, the
temperature is altered by placing the volume of fluid into a
housing having inner walls which define a chamber. The inner walls
are then heated or cooled to alter the temperature of the fluid
within the chamber.
[0017] In another particularly preferable aspect, the fluid is
pressurized by compressing the volume of liquid with a plate.
Alternatively, the fluid may be pressurized by inflating a bladder
which presses against the volume of fluid. The volume of fluid may
be selected from a wide variety of fluids including blood, saline
solutions, drugs, solutes and the like. In one aspect, the volume
of fluid will preferably be held within a compressible bag, with
the temperature of the fluid being altered while within the
bag.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic view of an exemplary system for
infusing a fluid which is at a desired temperature into a patient
according to the invention.
[0019] FIG. 2 is a cross-sectional side view of the system of FIG.
1 showing a temperature regulating element to regulate the
temperature of a reservoir of fluid according to the invention.
[0020] FIG. 3 illustrates the system of FIG. 2 with a compressor
for pressurizing the reservoir of fluid according to the
invention.
[0021] FIG. 4 illustrates the system of FIG. 2 with an alternative
compressor for pressurizing the reservoir of fluid according to the
invention.
DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0022] The invention provides systems and methods for infusing
various fluids which are at a desired temperature into a patient.
In this way, the systems and methods may be used to treat a variety
of ailments which require the infusion of a fluid while at a
particular temperature. For example, the invention may be employed
to heat a fluid to a temperature in the range from about 36.degree.
C. to about 42.degree. C. and then inject the fluid directly into
the blood stream to treat a patient suffering from hypothermia.
Alternatively, the invention may be employed to cool a fluid to a
temperature in the range from about 0.degree. C. to about
35.degree. C. and then inject the fluid directly into the blood
stream to treat a patient suffering from hyperthermia. In an
alternative aspect, the fluid may be cooled to a temperature in the
range from about 0.degree. C. to about 35.degree. C. and injected
into a vessel within the brain prior to a surgical procedure on the
brain. Other applications with which the invention may be used
include hypovolemia, cardiac arrest, stroke, and the like.
[0023] The systems and methods will preferably rely on the
application of positive pressure to infuse the fluids into the
patient's body. The application of such pressure will preferably be
controlled so that the fluid is introduced at a predetermined rate
and volume. In this manner, the fluids may be introduced without
relying on a gravity feed system, such as is commonly employed when
elevating IV bags to intravenously infuse various solutes into a
patient. Such systems and methods are therefore advantageous in
that they may be used in urgent care settings such as in the field
or in an ambulance, where elevation of the fluid may be impossible
or impractical.
[0024] The systems and methods of the invention will preferably be
compatible for use with fluids which are contained within
conventional storage containers, such as compressible bags, e.g. IV
bags. In this manner, the fluids do not need to be transferred to a
separate holder or container to facilitate heating or cooling.
Rather, the fluids may be directly heated or cooled within their
respective containers, thereby minimizing the time required to
place the fluids at the desired temperature. The systems and
methods of the invention may be employed to infuse a wide variety
of fluids into a patient, including blood, saline solutions, drugs,
solutes, and the like.
[0025] The system of the invention in some embodiments will
preferably be portable so that it may be useful in field
applications. In this manner, the systems may be transported to
urgent care locations and used to treat the patient. Such
portability may be provided by including a portable power supply,
such as batteries, to supply power to the temperature altering
device and to pressurize the fluid.
[0026] Referring now to FIG. 1, and exemplary system 10 for
infusing a fluid into a patient will be described. System 10
includes a housing 12 into which a fluid is placed prior to
introduction into the patient. The fluid exits housing 12 through a
tube 14. A needle 16 is conveniently provided to intravenously
introduce the fluid into the patient's blood stream. It will be
appreciated, however, that a wide variety of end dwelling devices
which are known in the art may be employed to place or infuse
various fluids into a patient's body including, for example,
sheaths, catheters, and the like. Such end dwelling devices may be
employed to introduce the fluids into arteries, veins, other body
lumens and sinuses, the abdominal cavity, and the like.
[0027] System 10 further includes a variety of switches, including
a set volume switch 18, a set rate switch 20 and a set temperature
switch 22. Switches 18, 20 and 22 may conveniently be configured as
toggle switches to increase or decrease numerical values which are
displayed on a screen 24. In this manner, a caregiver can quickly
set the volume and rate of fluid flow as well as the temperature of
the fluid using switches 18, 20 and 22. System 10 will further
include a processor (not shown) which is in electrical
communication with switches 18, 20 and 22 as well as screen 24. The
processor will also be electrically connected to any pressure
regulation devices used to control the volume and rate of fluid
flow as well as any temperature altering elements used to alter the
temperature of the fluid within housing 12 as described in greater
detail hereinafter.
[0028] Referring now to FIG. 2, a cross-sectional side view of
system 10 will be described. As shown, housing 12 includes inner
walls 26 which define a chamber 28 into which a reservoir 30 of
fluid is placed. Reservoir 30 is connected to tubing 14 to allow
the fluid to exit housing 12 through tubing 14. Reservoir 30 will
preferably comprise a conventional container, such as a
compressible bag, e.g., an IV bag, so that generally available
fluids may rapidly be placed into housing 12 prior to their
introduction into the patient.
[0029] Formed within housing 12 is a temperature altering element
32. As shown, temperature altering element 32 comprises an
electrically resistive wire through which current may be passed to
heat inner walls 26. In turn, heat from inner walls 26 is
transferred to reservoir 30 to heat the fluid to a desired
temperature. Power may be provided to temperature altering element
32 by a battery or by a separate AC or DC power source.
Conveniently, a thermistor 34 is placed in contact with reservoir
30 to monitor the temperature of the fluid. Thermistor 34 will be
in electrical communication with the processor so that actuation of
temperature altering element 32 may be controlled to precisely
control the temperature of the fluid within reservoir 30.
[0030] Although shown as an electrically resistive wire, various
other temperature altering elements may be included within housing
12 to either heat or cool the fluid within reservoir 30. For
example, other temperature altering elements may comprise various
chemicals, frozen liquids, heated liquids, heated gases, radio
frequency electrodes, thermoelectric crystals, and the like. One
advantage of using various temperature altering elements is that
certain elements may be used which do not require a stationary
power source. In this manner, system 10 may be configured to be a
portable system which may be used in the field without the need for
connecting the system to a fixed electrical power source.
[0031] A variety of mechanisms may be employed to pressurize the
fluid within reservoir 30 to control both the rate and volume of
fluid which is infused into the patient. In this manner, fluids may
be infused into the patient regardless of the elevation of housing
12. One exemplary embodiment of a compressor 36 that is used to
pressurize the fluid within reservoir 30 is illustrated in FIG. 3.
Compressor 36 comprises a solenoid 38 which is electrically
connected to the processor by a wire 40 to control actuation of
solenoid 38. Power may be supplied to solenoid 38 by a battery or
separate power source as needed. Solenoid 38 includes a rod 42
which is translated to move a plate 44 against reservoir 30. The
processor will preferably be employed to control the translation
rate and displacement of rod 42 to control the rate at which the
fluid is removed from reservoir 30 as well as the total volume
removed from reservoir 30. In this way, once the fluid is at the
desired temperature, solenoid 38 may be actuated at a given rate
and for a given time to control the rate at which the fluid is
introduced to the patient as well as the total volume of fluid that
is introduced.
[0032] Referring to FIG. 4, an alternative embodiment of a
compressor 46 for pressurizing the fluid within reservoir 30 will
be described. Compressor 46 comprises a bladder having an opening
48 into which a fluid may be introduced to expand the bladder. As
the bladder is expanded, it comes into contact with reservoir 30 to
pressurize the liquid within reservoir 30. A source of pressurized
fluid (not shown) will preferably be connected to opening 48 and
will be electrically connected to the processor to control the
total rate and volume of fluid introduced into the bladder. In this
way, the rate and the volume of fluid leaving reservoir 30 may be
controlled.
[0033] Although FIGS. 3 and 4 show two embodiments of compressors
it will be appreciated that other compressors for pressurizing the
fluid within reservoir 30 may be provided, including hydraulics,
pressurized gases, electromagnetic devices, and the like.
[0034] The invention has now been described in detail. However, it
will be appreciated that certain changes and modifications may be
made. Therefore, the scope and content of this invention are not
limited by the foregoing description. Rather, the scope and content
are to be defined by the following claims.
* * * * *