U.S. patent application number 16/416430 was filed with the patent office on 2019-09-05 for apparatus and methods for measuring peripheral venous pressure and applications of same.
The applicant listed for this patent is VANDERBILT UNIVERSITY. Invention is credited to Colleen Brophy, Susan Eagle, Kyle Mitchell Hocking, Kevin Sexton.
Application Number | 20190269861 16/416430 |
Document ID | / |
Family ID | 47558678 |
Filed Date | 2019-09-05 |
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United States Patent
Application |
20190269861 |
Kind Code |
A1 |
Eagle; Susan ; et
al. |
September 5, 2019 |
APPARATUS AND METHODS FOR MEASURING PERIPHERAL VENOUS PRESSURE AND
APPLICATIONS OF SAME
Abstract
A method of measuring peripheral venous pressure includes
providing a tubing operably connected between a fluid source and a
vein, a fluid controlling device for occluding the tubing and
configured to have an on position and an off position, and at least
one pressure sensor in fluid communication with the tubing, placed
between the fluid controlling device and the vein; selectively
passing fluid from the fluid source to the vein, through the
tubing, by the fluid controlling device; measuring both a fluid
pressure from the fluid source and a distal venous pressure from
the vein by the at least one pressure sensor when the fluid
controlling device is in the on position; and measuring the distal
venous pressure from the vein only by the at least one pressure
sensor when the fluid controlling device is in the off
position.
Inventors: |
Eagle; Susan; (Nashville,
TN) ; Sexton; Kevin; (Nashville, TN) ; Brophy;
Colleen; (Nashville, TN) ; Hocking; Kyle
Mitchell; (Nashville, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VANDERBILT UNIVERSITY |
Nashville |
TN |
US |
|
|
Family ID: |
47558678 |
Appl. No.: |
16/416430 |
Filed: |
May 20, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14232571 |
Mar 24, 2014 |
10293118 |
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PCT/US2012/046670 |
Jul 13, 2012 |
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16416430 |
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61508523 |
Jul 15, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/002 20130101;
A61B 2560/0266 20130101; A61B 5/066 20130101; A61B 5/6852 20130101;
A61B 5/02141 20130101; A61B 5/02158 20130101; A61M 5/5086 20130101;
A61B 5/02152 20130101 |
International
Class: |
A61M 5/50 20060101
A61M005/50; A61B 5/0215 20060101 A61B005/0215; A61B 5/021 20060101
A61B005/021 |
Claims
1. A method of measuring peripheral venous pressure (PVP),
comprising: providing a tubing operably connected between a fluid
source and a vein, a fluid controlling device for occluding the
tubing and configured to have an on position and an off position,
such that when the fluid controlling device is in the on position,
fluid in the tubing is allowed to pass the fluid controlling
device, and when the fluid controlling device is in the off
position, no fluid in the tubing is allowed to pass the fluid
controlling device, and at least one pressure sensor in fluid
communication with the tubing, placed between the fluid controlling
device and the vein; selectively passing fluid from the fluid
source to the vein, through the tubing, by the fluid controlling
device; measuring both a fluid pressure from the fluid source and a
distal venous pressure from the vein by the at least one pressure
sensor when the fluid controlling device is in the on position; and
measuring the distal venous pressure from the vein only by the at
least one pressure sensor when the fluid controlling device is in
the off position.
2. The method of claim 1, wherein the fluid controlling device is
manually or automatically controllable.
3. The method of claim 1, wherein the fluid controlling device
comprises a stopcock.
4. The method of claim 1, wherein the fluid controlling device
comprises an intravascular line occlusion mechanism.
5. The method of claim 4, wherein the intravascular line occlusion
mechanism is manual, automatic, or timed with cuff occlusion and
cuff release.
6. The method of claim 1, wherein the at least one pressure sensor
comprises a pressure transducer, a pressure transmitter, a pressure
sensor, a pressure indicator, a piezometer, or a pressure sensing
or detecting device.
7. The method of claim 1, further comprising processing the distal
venous pressure, as measured by the at least one pressure sensor,
to determine a hemodynamic parameter.
8. The method of claim 7, wherein the hemodynamic parameter
includes at least one of a maximum value of the PVP, a rate of
rise/slope of the PVP, and/or a rate of fall/slope of the PVP.
9. The method of claim 7, further comprising displaying the
hemodynamic parameter on a display.
10. The method of claim 9, wherein communication between the at
least one pressure sensor and the display is remotely transmitted
via Bluetooth.RTM. or radiofrequency mechanism.
11. A system of measuring peripheral venous pressure (PVP),
comprising: a fluid source; a tube operably connected between the
fluid source and a vein; a fluid controlling device for occluding
the tube, wherein the fluid controlling device includes an on
position and an off position, such that when the fluid controlling
device is in the on position, fluid in the tube is allowed to pass
the fluid controlling device, and when the fluid controlling device
is in the off position, no fluid in the tube is allowed to pass the
fluid controlling device; and a pressure sensor in fluid
communication with the tube and disposed between the fluid
controlling device and the vein, wherein the fluid controlling
device passes fluid from the fluid source to the vein, through the
tube, wherein the pressure sensor measures a fluid pressure from
the fluid source and a distal venous pressure from the vein while
the fluid controlling device is in the on position, and wherein the
pressure sensor only measures the distal venous pressure from the
vein while the fluid controlling device is in the off position.
12. The system of claim 11, wherein the fluid controlling device is
manually or automatically controllable.
13. The system of claim 11, wherein the fluid controlling device
comprises a stopcock.
14. The system of claim 11, wherein the fluid controlling device
comprises an intravascular line occlusion mechanism.
15. The system of claim 14, wherein the intravascular line
occlusion mechanism is manual, automatic, or timed with cuff
occlusion and cuff release.
16. The system of claim 11, wherein the pressure sensor comprises a
pressure transducer, a pressure transmitter, a pressure sensor, a
pressure indicator, a piezometer, or a pressure sensing or
detecting device.
17. The system of claim 11, wherein the distal venous pressure, as
measured by the pressure sensor, is processed to determine a
hemodynamic parameter.
18. The system of claim 17, wherein the hemodynamic parameter
includes at least one of a maximum value of the PVP, a rate of
rise/slope of the PVP, and/or a rate of fall/slope of the PVP.
19. The system of claim 17, further comprising displaying the
hemodynamic parameter on a display.
20. A device for measuring peripheral venous pressure (PVP),
comprising: a pressure sensor in fluid communication with a tube,
wherein a first end of the tube is in fluid communication with a
fluid source and a second end of the tube is in fluid communication
with a vein, wherein the pressure sensor is disposed along the tube
between a fluid controlling device capable of occluding the tube
and the vein, wherein when the fluid controlling device is in an on
position, the tube is not occluded, and when the fluid controlling
device is in an off position, the tube is occluded, such that the
pressure sensor measures a fluid pressure from the fluid source and
a distal venous pressure from the vein while the fluid controlling
device is in the on position, and the pressure sensor only measures
the distal venous pressure from the vein while the fluid
controlling device is in the off position.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application is a continuation application of U.S.
patent application Ser. No. 14/232,571, filed Mar. 24, 2014, now
allowed, which is a U.S. national phase application under 35 U.S.C.
.sctn. 371 of International Patent Application No.
PCT/US2012/046670, filed Jul. 13, 2012, which itself claims
priority to and the benefit of U.S. provisional patent application
Ser. No. 61/508,523, filed on Jul. 15, 2011, which are incorporated
herein in their entireties by reference.
[0002] Some references, which may include patents, patent
applications and various publications, are cited and discussed in
the description of this invention. The citation and/or discussion
of such references is provided merely to clarify the description of
the present invention and is not an admission that any such
reference is "prior art" to the invention described herein. All
references cited and discussed in this specification are
incorporated herein by reference in their entireties and to the
same extent as if each reference was individually incorporated by
reference.
FIELD OF THE INVENTION
[0003] This invention relates generally to intravenous (IV)
therapy, and more particularly to apparatus and methods for
measuring peripheral venous pressure (PVP), and its application in
monitoring intravascular placement of a peripheral IV catheter.
BACKGROUND OF THE INVENTION
[0004] Invasive hemodynamic monitoring is routinely used in medical
environments, such as operating rooms and critical-care settings,
for determining volume status and cardiac function in patients.
Limitations of invasive monitoring include advanced training, cost,
time constraints, and potential for infectious and vascular
complications. Newer sophisticated non-invasive monitoring devices
for earlier detection of intravascular volume changes using
plethysmography and muscle oxygen saturation may be impractical and
expensive. Lack of sensitivity of traditional monitoring has
prompted researchers to look for alternative means to more
accurately estimate intravascular volume status.
[0005] Peripheral venous pressure (PVP) is increasingly used in the
assessment of intravascular volume status. PVP accurately reflects
central venous pressure, particularly in the setting of acute
hemorrhage (>1000 mL). A method for dynamic measurement of
intravascular volume status is cuff-occluded rate of rise of
peripheral venous pressure (CORRP). CORRP allows for earlier
detection of acute hypovolemia compared to traditional monitoring
in animal models. The challenge is how to measure absolute PVP and
CORRP in a non-invasive manner rather accurately.
[0006] Further, while seemingly simple, proper intravascular
placement of the intravenous (IV) catheter is mandatory for
effective IV volume resuscitation and IV pharmacologic
administration. Malpositioning or misplacing of IV catheters may
occur at any time during hospitalization or when a patient is in a
status under the potential need of IV volume resuscitation and/or
IV pharmacologic administration. Ambulatory patients may
inadvertently displace the catheter, often secured with tape;
patients in the operating room setting often have their arms tucked
in sheets, away from the operative field, precluding inspection of
the IV insertion site for signs of infiltration; pediatric patients
often have IV catheters secured with devices to prevent patient
tampering--also obscuring the IV insertion site.
[0007] Malpositioning of a peripheral IV catheter into the
extravascular space precludes the patient from receiving necessary
resuscitative therapy. Fluid administration into subcutaneous
tissue or fascia may result in compartment syndrome and loss of the
extremity. Tissue necrosis and gangrene may result from tissue
infiltration of vasoactive medications.
[0008] Therefore, a heretofore unaddressed need exists in the art
to address the aforementioned deficiencies and inadequacies.
SUMMARY OF THE INVENTION
[0009] In one aspect of the present invention, an apparatus for
measuring peripheral venous pressure (PVP) includes: a tubing
having a first end and an opposite, second end, where the first end
is connectable to a fluid source, and the second end is connectable
to a vein, a fluid controlling device in fluid communication with
the tubing, placed between the first and second ends of the tubing
and configured to have an on position and an off position, a port
device in fluid communication with the tubing, placed between the
fluid controlling device and the second end of the tubing, at least
one pressure sensor in fluid communication with the tubing through
the port device, configured to measure fluid pressures therein, and
a processor electrically coupled with the at least one pressure
sensor for processing the measured fluid pressures by the at least
one pressure sensor. In operation, when the fluid controlling
device is in the on position, fluid flow in the tubing is allowed
to pass through the fluid controlling device, such that the at
least one pressure sensor measures both a fluid pressure from the
fluid source and a distal venous pressure from the vein, and when
the fluid controlling device is in the off position, no fluid flow
in the tubing is allowed to pass through the fluid controlling
device, such that the at least one pressure sensor measures the
distal venous pressure from the vein only.
[0010] The fluid controlling device may be manually or
automatically controllable. In one embodiment, the fluid
controlling device includes a stopcock. In another embodiment, the
fluid controlling device includes an intravascular line occlusion
mechanism, which may be manual, automatic, or timed with cuff
occlusion and cuff release.
[0011] In one embodiment, the port device includes a T-piece or
Y-piece connector.
[0012] In one embodiment, the at least one pressure sensor includes
a pressure transducer.
[0013] The processor in one embodiment is associated with a circuit
board of data acquisition and process.
[0014] In one embodiment, the apparatus further includes a display
in communication with the processor for displaying the processed
fluid pressures. The display may include a graphic interface.
[0015] The apparatus in one embodiment further includes one or more
additional port device in fluid communication with the tubing,
placed between the fluid source and the port device or between the
port device and the vein for measuring fluid pressures therein.
[0016] In one embodiment, the apparatus further includes an IV
catheter for connecting the second end of the tubing to the
vein.
[0017] In another aspect, the invention relates to an apparatus for
measuring PVP. In one embodiment, the apparatus includes: a tubing
having a first end and an opposite, second end, where the first end
is connectable to a fluid source, and the second end is connectable
to a vein, a fluid controlling device in fluid communication with
the tubing, placed between the first and second ends of the tubing
and configured to have an on position and an off position, and at
least one pressure sensor in fluid communication with the tubing,
placed between the fluid controlling device and the second end of
tubing and configured to measure fluid pressures therein. In
operation, when the fluid controlling device is in the on position,
fluid flow in the tubing is allowed to pass through the fluid
controlling device, such that the at least one pressure sensor
measures both a fluid pressure from the fluid source and a distal
venous pressure from the vein, and when the fluid controlling
device is in the off position, no fluid flow in the tubing is
allowed to pass through the fluid controlling device, such that the
at least one pressure sensor measures the distal venous pressure
from the vein only.
[0018] The fluid controlling device may be manually or
automatically controllable. In one embodiment, the fluid
controlling device includes a stopcock. In another embodiment, the
fluid controlling device includes an intravascular line occlusion
mechanism, which may be manual, automatic, or timed with cuff
occlusion and cuff release.
[0019] In one embodiment, the apparatus further includes a port
device in fluid communication with the tubing, wherein the at least
one pressure sensor is in fluid communication with the tubing
through the port device. In a further embodiment, the port device
includes a T-piece or Y-piece connector.
[0020] In one embodiment, the at least one pressure sensor includes
a pressure transducer.
[0021] In one embodiment, the apparatus further includes a
processor in communication with the at least one pressure sensor
for processing the measured fluid pressures by the at least one
pressure sensor.
[0022] In yet another aspect of the invention, a method of
measuring PVP includes: providing a tubing operably connected
between a fluid source and a vein, a fluid controlling device in
fluid communication with the tubing, placed in the tubing and
configured to have an on position and an off position, and at least
one pressure sensor in fluid communication with the tubing, placed
between the fluid controlling device and the vein, selectively
passing fluid from the fluid source to the vein through the tubing
by the fluid controlling device, measuring both a fluid pressure
from the fluid source and a distal venous pressure from the vein by
the at least one pressure sensor when fluid controlling device is
in the on position, and measuring the distal venous pressure from
the vein only by the at least one pressure sensor when the fluid
controlling device is in the off position.
[0023] The fluid controlling device may be manually or
automatically controllable. In one embodiment, the fluid
controlling device includes a stopcock. In another embodiment, the
fluid controlling device includes an intravascular line occlusion
mechanism, which may be manual, automatic, or timed with cuff
occlusion and cuff release.
[0024] In a further aspect, the invention relates to an apparatus
for monitoring intravascular placement of a peripheral IV catheter.
In one embodiment, the apparatus includes: a tubing with a first
end and an opposite, second end, where in use, the first end is
connected to a fluid source, and the second end is connected to the
peripheral IV catheter that in turn is placed in a vein, a
connector in fluid communication with the tubing, where the
connector has first and second ports connected to the tubing and a
narrow section formed therebetween, where the narrow section has an
inner diameter smaller than that of the tubing, first and second
pressure sensors in fluid communication with the tubing through the
first and second ports of the connector, respectively, configured
to measure fluid pressures therein, and a processor electrically
coupled with the first and second pressure sensors for processing
the measured fluid pressures by the first and second pressure
sensors. When fluid passes from the fluid source to the IV catheter
through the connector, a pressure drop of the fluid is generated at
the narrow section, where the pressure drop is measureable by the
first and second pressure sensors for calculating a pressure change
rate dP/dt.
[0025] In one embodiment, each of the first and second pressure
sensors includes a pressure transducer.
[0026] In one embodiment, the IV catheter is properly placed when
the pressure change rate dP/dt is substantially constant or
increases, and the IV catheter is not properly placed when the
pressure change rate dP/dt is substantially absent or
decreases.
[0027] The processor in one embodiment is associated with a circuit
board of data acquisition and process.
[0028] In one embodiment, the apparatus further includes a display
in communication with the processor for displaying the processed
data. In a further embodiment, the display includes a graphic
interface.
[0029] The apparatus in one embodiment further includes one or more
additional pressure sensors in communication with the tubing,
placed between the fluid source and the connector or between the
connector and the vein for measuring fluid pressures therein.
[0030] In one aspect of the present invention, an apparatus for
monitoring intravascular placement of a peripheral IV catheter
includes: a tubing having a first end, an opposite, second end, and
a narrow section formed therebetween, where in use, the first end
is connected to a fluid source, and the second end is connected to
the peripheral IV catheter that in turn is placed in a vein, and
where the narrow section has an inner diameter smaller than that of
other part of the tubing, first and second pressure sensors in
fluid communication with the tubing, wherein one of the first and
second pressure sensors is placed on a distal side of the narrow
section to the IV catheter, and the other of the first and second
pressure sensors is placed on a proximal side of the narrow section
to the IV catheter, and a processor electrically coupled with the
first and second pressure sensors for processing the measured fluid
pressures by the first and second pressure sensors. When fluid
flows from the fluid source to the IV catheter through the narrow
section of the tubing, a pressure drop of the fluid is generated at
the narrow section, and the pressure drop is measureable by the
first and second pressure sensors for calculating a pressure change
rate dP/dt.
[0031] The tubing in one embodiment includes a connector having a
narrow portion and two ports on both sides of the narrow portions,
where the narrow portion forms the narrow section of the tubing by
having an inner diameter smaller than the diameter of the tubing,
and the two ports are configured to be connected with the first and
second pressure sensors, respectively.
[0032] In one embodiment, each of the first and second pressure
sensors includes a pressure transducer.
[0033] In one embodiment, the IV catheter is properly placed when
the pressure change rate dP/dt is substantially constant or
increases, and the IV catheter is not properly placed when the
pressure change rate dP/dt is substantially absent or
decreases.
[0034] The processor in one embodiment is associated with a circuit
board of data acquisition and process.
[0035] In one embodiment, the apparatus further includes a display
in communication with the processor for displaying the processed
data. In a further embodiment, the display includes a graphic
interface.
[0036] The apparatus in one embodiment further includes one or more
additional pressure sensors in communication with the tubing,
placed between the fluid source and the connector or between the
connector and the vein for measuring fluid pressures therein.
[0037] In another aspect of the present invention, a method for
monitoring intravascular placement of a peripheral IV catheter
includes: providing a tubing having a first end connected to a
fluid source, and an opposite, second end connected to the
peripheral IV catheter that in turn is placed in a vein, wherein
the tubing has a narrow section between the first and second ends,
where the narrow section has an inner diameter smaller than that of
other part of the tubing, passing fluid from the fluid source to
the vein through the tubing, measuring a pressure drop at the
narrow section by first and second pressure sensors placed on both
sides of the narrow section of the tubing, and determining whether
the IV catheter is properly placed according to a pressure change
rate dP/dt of the pressure drop.
[0038] In one embodiment, the IV catheter is properly placed when
the pressure change rate dP/dt is substantially constant or
increases, and the IV catheter is not properly placed when the
pressure change rate dP/dt is substantially absent or
decreases.
[0039] In one embodiment, the method further includes: displaying
the determination results as to whether the IV catheter is properly
placed on a display.
[0040] In yet another aspect of the present invention, a method for
monitoring intravascular placement of a peripheral IV catheter
includes: providing a tubing having a first end connected to a
fluid source, and an opposite, second end connected to the
peripheral IV catheter that in turn is placed in a vein, and a
pressure sensor in fluid communication with the tubing, placed
between the fluid source and the IV catheter; passing fluid from
the fluid source to the vein through the tubing; measuring
pressures of the fluid in the tubing by the pressure sensor; and
determining an IV position or intravascular location of the IV
catheter according to an algorithm in which the measured pressures
are processed.
[0041] In one embodiment, the algorithm is based on analyzing
waveforms of the measured pressures to include mean pressure,
integral of waveform, variance, standard deviation, slope, sum of
squares, correlation along a straight line, and changes or delta of
any of these variables. The variables are measured, recorded, and
compared over pre-determined time intervals to determine IV
position.
[0042] The method may further include displaying the determined IV
position or intravascular location of the IV catheter on a
display.
[0043] In one aspect, the present invention relates to a method of
measuring PVP. In one embodiment, the method includes providing a
tubing operably connected between a fluid source and a vein, a
fluid controlling device for occluding the tubing and configured to
have an on position and an off position, such that when the fluid
controlling device is in the on position, fluid in the tubing is
allowed to pass the fluid controlling device, and when the fluid
controlling device is in the off position, no fluid in the tubing
is allowed to pass the fluid controlling device, and at least one
pressure sensor in fluid communication with the tubing, placed
between the fluid controlling device and the vein; selectively
passing fluid from the fluid source to the vein, through the
tubing, by the fluid controlling device; measuring both a fluid
pressure from the fluid source and a distal venous pressure from
the vein by the at least one pressure sensor when the fluid
controlling device is in the on position; and measuring the distal
venous pressure from the vein only by the at least one pressure
sensor when the fluid controlling device is in the off
position.
[0044] In one embodiment, the fluid controlling device is manually
or automatically controllable.
[0045] In one embodiment, the fluid controlling device comprises a
stopcock.
[0046] In one embodiment, the fluid controlling device comprises an
intravascular line occlusion mechanism.
[0047] In one embodiment, the intravascular line occlusion
mechanism is manual, automatic, or timed with cuff occlusion and
cuff release.
[0048] In one embodiment, the at least one pressure sensor
comprises a pressure transducer, a pressure transmitter, a pressure
sensor, a pressure indicator, a piezometer, or a pressure sensing
or detecting device.
[0049] In one embodiment, the method further comprises processing
the distal venous pressure, as measured by the at least one
pressure sensor, to determine a hemodynamic parameter. In one
embodiment, the hemodynamic parameter includes at least one of a
maximum value of the PVP, a rate of rise/slope of the PVP, and/or a
rate of fall/slope of the PVP.
[0050] In one embodiment, the method further comprises displaying
the hemodynamic parameter on a display. In one embodiment,
communication between the at least one pressure sensor and the
display is remotely transmitted via Bluetooth.RTM. or
radiofrequency mechanism.
[0051] In another aspect, the present invention relates to a system
of measuring PVP. In one embodiment, the system includes a fluid
source; a tube operably connected between the fluid source and a
vein; a fluid controlling device for occluding the tube, wherein
the fluid controlling device includes an on position and an off
position, such that when the fluid controlling device is in the on
position, fluid in the tube is allowed to pass the fluid
controlling device, and when the fluid controlling device is in the
off position, no fluid in the tube is allowed to pass the fluid
controlling device; and a pressure sensor in fluid communication
with the tube and disposed between the fluid controlling device and
the vein, where the fluid controlling device passes fluid from the
fluid source to the vein, through the tube, the pressure sensor
measures a fluid pressure from the fluid source and a distal venous
pressure from the vein while the fluid controlling device is in the
on position, and the pressure sensor only measures the distal
venous pressure from the vein while the fluid controlling device is
in the off position.
[0052] In one embodiment, the fluid controlling device is manually
or automatically controllable.
[0053] In one embodiment, the fluid controlling device comprises a
stopcock.
[0054] In one embodiment, the fluid controlling device comprises an
intravascular line occlusion mechanism. In one embodiment, the
intravascular line occlusion mechanism is manual, automatic, or
timed with cuff occlusion and cuff release.
[0055] In one embodiment, the pressure sensor comprises a pressure
transducer, a pressure transmitter, a pressure sensor, a pressure
indicator, a piezometer, or a pressure sensing or detecting
device.
[0056] In one embodiment, the distal venous pressure, as measured
by the pressure sensor, is processed to determine a hemodynamic
parameter. In one embodiment, the hemodynamic parameter includes at
least one of a maximum value of the PVP, a rate of rise/slope of
the PVP, and/or a rate of fall/slope of the PVP.
[0057] In one embodiment, the system further comprises displaying
the hemodynamic parameter on a display.
[0058] In yet another aspect, the present invention relates to a
device for measuring PVP comprising a pressure sensor in fluid
communication with a tube, wherein a first end of the tube is in
fluid communication with a fluid source and a second end of the
tube is in fluid communication with a vein, where the pressure
sensor is disposed along the tube between a fluid controlling
device capable of occluding the tube and the vein, wherein when the
fluid controlling device is in an on position, the tube is not
occluded, and when the fluid controlling device is in an off
position, the tube is occluded, such that the pressure sensor
measures a fluid pressure from the fluid source and a distal venous
pressure from the vein while the fluid controlling device is in the
on position, and the pressure sensor only measures the distal
venous pressure from the vein while the fluid controlling device is
in the off position.
[0059] These and other aspects of the present invention will become
apparent from the following description of the preferred embodiment
taken in conjunction with the following drawings, although
variations and modifications therein may be affected without
departing from the spirit and scope of the novel concepts of the
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] The accompanying drawings illustrate one or more embodiments
of the invention and, together with the written description, serve
to explain the principles of the invention. Wherever possible, the
same reference numbers are used throughout the drawings to refer to
the same or like elements of an embodiment.
[0061] FIG. 1A shows schematically an apparatus for measuring
peripheral venous pressure according to one embodiment of the
present invention.
[0062] FIG. 1B shows an enlarged view of a stopcock of the fluid
controlling device according to one embodiment of the present
invention, where the fluid controlling device is in an on
position.
[0063] FIG. 1C shows an enlarged view of a stopcock of the fluid
controlling device according to one embodiment of the present
invention, where the fluid controlling device is in an off
position.
[0064] FIG. 1D shows an enlarged view of a T-piece connector
according to one embodiment of the present invention.
[0065] FIG. 1E shows an enlarged view of a Y-piece connector
according to one embodiment of the present invention.
[0066] FIG. 2 shows a flowchart of measuring peripheral venous
pressure according to one embodiment of the present invention.
[0067] FIG. 3A shows schematically an apparatus for monitoring
intravascular placement of a peripheral IV catheter according to
one embodiment of the present invention.
[0068] FIG. 3B shows an enlarged view of a connector according to
one embodiment of the present invention.
[0069] FIG. 4 shows a flowchart of monitoring intravascular
placement of a peripheral IV catheter according to one embodiment
of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0070] The present invention is more particularly described in the
following examples that are intended as illustrative only since
numerous modifications and variations therein will be apparent to
those skilled in the art. Various embodiments of the invention are
now described in detail. Referring to the drawings, like numbers,
if any, indicate like components throughout the views. As used in
the description herein and throughout the claims that follow, the
meaning of "a", "an", and "the" includes plural reference unless
the context clearly dictates otherwise. Also, as used in the
description herein and throughout the claims that follow, the
meaning of "in" includes "in" and "on" unless the context clearly
dictates otherwise. Moreover, titles or subtitles may be used in
the specification for the convenience of a reader, which shall have
no influence on the scope of the present invention. Additionally,
some terms used in this specification are more specifically defined
below.
Definitions
[0071] The terms used in this specification generally have their
ordinary meanings in the art, within the context of the invention,
and in the specific context where each term is used. Certain terms
that are used to describe the invention are discussed below, or
elsewhere in the specification, to provide additional guidance to
the practitioner regarding the description of the invention. For
convenience, certain terms may be highlighted, for example using
italics and/or quotation marks. The use of highlighting has no
influence on the scope and meaning of a term; the scope and meaning
of a term is the same, in the same context, whether or not it is
highlighted. It will be appreciated that same thing can be said in
more than one way. Consequently, alternative language and synonyms
may be used for any one or more of the terms discussed herein, nor
is any special significance to be placed upon whether or not a term
is elaborated or discussed herein. Synonyms for certain terms are
provided. A recital of one or more synonyms does not exclude the
use of other synonyms. The use of examples anywhere in this
specification, including examples of any terms discussed herein, is
illustrative only, and in no way limits the scope and meaning of
the invention or of any exemplified term. Likewise, the invention
is not limited to various embodiments given in this
specification.
[0072] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention pertains. In the
case of conflict, the present document, including definitions will
control.
[0073] As used herein, "around", "about" or "approximately" shall
generally mean within 20 percent, preferably within 10 percent, and
more preferably within 5 percent of a given value or range.
Numerical quantities given herein are approximate, meaning that the
term "around", "about" or "approximately" can be inferred if not
expressly stated.
[0074] As used herein, the terms "comprising," "including,"
"having," "containing," "involving," and the like are to be
understood to be open-ended, i.e., to mean including but not
limited to.
[0075] As used herein, the terms "intravenous therapy",
"intravenous tubing", the "intravenous" prefix, its abbreviation
"IV" or the like generally refer to the infusion of liquid
substances directly into a vein.
Overview of the Invention
[0076] The present invention discloses, among other things,
apparatus and methods of utilizing IV tubing for measuring absolute
PVP and CORRP in a non-invasive manner, and applications of the
same in monitoring intravascular placement of a peripheral IV
catheter. Further measurements of the venous waveform with or
without fluids actively flowing from a fluid source are performed.
An algorithm is utilized for determining proper or malpositioned IV
catheters. This algorithm is based on analyzing the waveform to
include mean pressure, integral of waveform, variance, standard
deviation, slope, sum of squares, correlation along a straight
line, and changes or delta of any of these variables. These
variables are measured, recorded, and compared over pre-determined
time intervals to determine IV position. Based on these
measurements, an alert or other signal is displayed to the operator
regarding the IV position. This apparatus may communicate
wirelessly so the alert can be displayed to the operator.
[0077] In one aspect of the present invention, an apparatus for
measuring PVP includes a tubing having a first end connectable to a
fluid source and a second end connectable to a vein, a fluid
controlling device in fluid communication with the tubing, placed
between the first and second ends of the tubing and configured to
have an on position and an off position.
[0078] The apparatus also includes a port device in fluid
communication with the tubing, placed between the fluid controlling
device and the second end of the tubing, at least one pressure
sensor in fluid communication with the tubing through the port
device, configured to measure fluid pressures therein, and a
processor electrically coupled with the at least one pressure
sensor for processing the measured fluid pressures by the at least
one pressure sensor.
[0079] In use, when the fluid controlling device is in the on
position, fluid flow in the tubing is allowed to pass through the
fluid controlling device, such that the at least one pressure
sensor measures both a fluid pressure from the fluid source and a
distal venous pressure from the vein, and when the fluid
controlling device is in the off position, no fluid flow in the
tubing is allowed to pass through the fluid controlling device,
such that the at least one pressure sensor measures the distal
venous pressure from the vein only.
[0080] In another aspect of the invention, an apparatus for
measuring PVP includes a tubing having a first end connectable to a
fluid source and a second end connectable to a vein, a fluid
controlling device in fluid communication with the tubing, placed
between the first and second ends of the tubing and configured to
have an on position and an off position, and at least one pressure
sensor in fluid communication with the tubing, placed between the
fluid controlling device and the second end of tubing and
configured to measure fluid pressures therein. In use, when the
fluid controlling device is in the on position, fluid flow in the
tubing is allowed to pass through the fluid controlling device,
such that the at least one pressure sensor measures both a fluid
pressure from the fluid source and a distal venous pressure from
the vein, and when the fluid controlling device is in the off
position, no fluid flow in the tubing is allowed to pass through
the fluid controlling device, such that the at least one pressure
sensor measures the distal venous pressure from the vein only.
[0081] In yet another aspect of the invention, a method of
measuring PVP includes providing a tubing operably connected
between a fluid source and a vein, a fluid controlling device in
fluid communication with the tubing, placed in the tubing and
configured to have an on position and an off position, and at least
one pressure sensor in fluid communication with the tubing, placed
between the fluid controlling device and the vein, selectively
passing fluid from the fluid source to the vein through the tubing
by the fluid controlling device, measuring both a fluid pressure
from the fluid source and a distal venous pressure from the vein by
the at least one pressure sensor when fluid controlling device is
in the on position, and measuring the distal venous pressure from
the vein only by the at least one pressure sensor when the fluid
controlling device is in the off position.
[0082] In one aspect, the invention relates to an apparatus for
monitoring intravascular placement of a peripheral IV catheter. The
apparatus includes a tubing with a first end and an opposite,
second end, where in use, the first end is connected to a fluid
source, and the second end is connected to the peripheral IV
catheter that in turn is placed in a vein. The apparatus also
includes a connector in fluid communication with the tubing, where
the connector has first and second ports connected to the tubing
and a narrow section formed therebetween. The narrow section has an
inner diameter smaller than that of the tubing. Further, the
apparatus includes first and second pressure sensors in fluid
communication with the tubing through the first and second ports of
the connector, respectively, configured to measure fluid pressures
therein, and a processor electrically coupled with the first and
second pressure sensors for processing the measured fluid pressures
by the first and second pressure sensors.
[0083] When fluid passes from the fluid source to the IV catheter
through the connector, a pressure drop of the fluid is generated at
the narrow section, where the pressure drop is measureable by the
first and second pressure sensors for calculating a pressure change
rate dP/dt.
[0084] In another aspect, the present invention relates to an
apparatus for monitoring intravascular placement of a peripheral IV
catheter. The apparatus in one embodiment includes a tubing having
a first end, an opposite, second end, and a narrow section formed
therebetween, where in use, the first end is connected to a fluid
source, and the second end is connected to the peripheral IV
catheter that in turn is placed in a vein, and where the narrow
section has an inner diameter smaller than that of other part of
the tubing.
[0085] The apparatus further has first and second pressure sensors
in fluid communication with the tubing, where one of the first and
second pressure sensors is placed on a distal side of the narrow
section to the IV catheter, and the other of the first and second
pressure sensors is placed on a proximal side of the narrow section
to the IV catheter, and a processor electrically coupled with the
first and second pressure sensors for processing the measured fluid
pressures by the first and second pressure sensors. When fluid
flows from the fluid source to the IV catheter through the narrow
section of the tubing, a pressure drop of the fluid is generated at
the narrow section, and the pressure drop is measureable by the
first and second pressure sensors for calculating a pressure change
rate dP/dt.
[0086] In a further aspect, the present invention relates to a
method for monitoring intravascular placement of a peripheral IV
catheter. In one embodiment, the method includes providing a tubing
having a first end connected to a fluid source, and an opposite,
second end connected to the peripheral IV catheter that in turn is
placed in a vein. The tubing is configured to have a narrow section
between the first and second ends. The narrow section has an inner
diameter smaller than that of other part of the tubing.
[0087] The method also includes passing fluid from the fluid source
to the vein through the tubing, measuring a pressure drop at the
narrow section by first and second pressure sensors placed on both
sides of the narrow section of the tubing, and determining whether
the IV catheter is properly placed according to a pressure change
rate dP/dt of the pressure drop.
[0088] In yet a further aspect, the present invention relates to a
method for monitoring intravascular placement of a peripheral IV
catheter. In one embodiment, the method includes, among other
things, providing a tubing having a first end connected to a fluid
source, and an opposite, second end connected to the peripheral IV
catheter that in turn is placed in a vein, where the tubing may or
may not have a narrow section between the first and second ends,
and a pressure sensor in fluid communication with the tubing,
placed between the fluid source and the IV catheter, passing fluid
from the fluid source to the vein through the tubing, measuring
pressures of the fluid in the tubing by the pressure sensor, and
determining an IV position or intravascular location of the IV
catheter according to an algorithm in which the measured pressures
are processed. The algorithm is based on analyzing waveforms of the
measured pressures to include mean pressure, integral of waveform,
variance, standard deviation, slope, sum of squares, correlation
along a straight line, and changes or delta of any of these
variables. The variables are measured, recorded, and compared over
pre-determined time intervals to determine IV position.
Accordingly, these data do not require a pressure differential.
Thus, only one pressure sensor is needed between the fluid source
and the IV, and the data is collected while the fluid source is
running thru the tubing into the IV.
[0089] These and other aspects of the present invention are more
specifically described below.
Implementations and Examples of the Invention
[0090] Without intent to limit the scope of the invention,
exemplary methods and their related results according to the
embodiments of the present invention are given below. Note that
titles or subtitles may be used in the examples for convenience of
a reader, which in no way should limit the scope of the invention.
Moreover, certain theories are proposed and disclosed herein;
however, in no way they, whether they are right or wrong, should
limit the scope of the invention so long as the invention is
practiced according to the invention without regard for any
particular theory or scheme of action.
[0091] The description will be made as to the embodiments of the
present invention in conjunction with the accompanying drawings in
FIGS. 1-4. In accordance with the purposes of this disclosure, as
embodied and broadly described herein, this disclosure, in one
aspect, relates to compression and aggregation-resistant particles
of crumpled soft sheets and methods of synthesizing same.
[0092] Referring to FIGS. 1A-1E, and particular FIG. 1A first, an
apparatus for measuring the PVP is shown according to one
embodiment of the present invention. The apparatus 100 is
configured for measuring, among other things, absolute PVP and
CORRP in a non-invasive manner. The apparatus 100 may be fixed or
may be portable for the convenience of the medical environments
where the system is utilized.
[0093] As shown in FIG. 1A, the apparatus 100 includes a tubing
110, a fluid source 120, a fluid controlling device 130, a port
device 140, at least one pressure sensor 150, a circuit board 160,
and a display 170.
[0094] The tubing 110 has a first end 112 and an opposite, second
end 114. The first end 112 is connectable to the fluid source 120,
such as an IV bag, a saline bag, or other bags or containers
providing IV fluids. The second end 114 is connectable to a vein.
In one embodiment, an IV catheter 116, which is a thin tube for
inserting into a body, is provided for connecting the second end
114 of the tubing 110 to the vein.
[0095] The fluid controlling device 130 is in fluid communication
with the tubing 110, and is placed between the first and second
ends 112 and 114 of the tubing 110. The fluid controlling device
130 is configured to have an on position and an off position. The
fluid controlling device 130 may be manually or automatically
controllable. For example, the fluid controlling device 130 as
shown in FIG. 1A includes a stopcock 132, which is shown in
enlarged views in FIGS. 1B and 1C. By switching the stopcock 132,
the fluid controlling device 130 can be manually controllable in
the on position as shown in FIG. 1B, or in the off position as
shown in FIG. 1C. When the fluid controlling device 130 is in the
on position as shown in FIG. 1B, fluid flow in the tubing 110 is
allowed to pass through the fluid controlling device 130. When a
user controls the fluid controlling device 130 to be in the off
position as shown in FIG. 1C, no fluid flow in the tubing 110 is
allowed to pass through the fluid controlling device 130. In
certain embodiments, the fluid controlling device 130 may include
an intravascular line occlusion mechanism, which may be manual,
automatic, or timed with cuff occlusion and cuff release.
[0096] The port device 140 is in fluid communication with the
tubing 110, and is placed between the fluid controlling device 130
and the second end 114 of the tubing 110. The port device 140 may
include a T-piece connector, which is shown in an enlarged view in
FIG. 1D, or a Y-piece connector 118, which is shown in an enlarged
view in FIG. 1E.
[0097] The at least one pressure sensor 150 is in fluid
communication with the tubing 110 through the port device 140, and
is configured to measure fluid pressures therein. When the port
device 140 includes the T-piece connector as shown in FIG. 1D, the
at least one pressure sensor 150 is in fluid communication with the
tubing 110 through the port 142 of the T-piece connector 140 for
measuring the fluid pressures. The at least one pressure sensor may
include a pressure transducer, a pressure transmitter, a pressure
sensor, a pressure indicator, a piezometer, or any other types of
pressure sensing or detecting devices or elements.
[0098] A processor is electrically coupled with the at least one
pressure sensor 150 for processing the measured fluid pressures by
the at least one pressure sensor 150. The measured fluid pressures
may be processed by the processor for further data calculation and
analysis, such as monitoring the fluid volume being provided in the
IV therapy. In this exemplary embodiment shown in FIG. 1A, the
processor is associated with the circuit board 160 of data
acquisition and process, and the display 170 is in communication
with the processor on the circuit board 160 for displaying the
processed fluid pressures. The circuit board 160 may include
standard computer input/output ports, such as USB ports, for
further data process. The display 170 may include a graphic
interface, such as a screen, or any other types of graphic
information output devices or elements. Communication between the
sensor and the display may be remotely transmitted via Bluetooth or
radiofrequency mechanisms.
[0099] In operation, when the fluid controlling device 130 is in
the on position, as shown in FIG. 1B, fluid flow in the tubing is
allowed to pass through the fluid controlling device 130, such that
the at least one pressure sensor 150 measures a pressure including
a fluid pressure from the fluid source 120 and a distal venous
pressure from the vein. Such measurement is done dynamically and
continuously. Further, when the user operates or turns the stopcock
132 of the fluid controlling device 130 to the off position, as
shown in FIG. 1C, no fluid flow in the tubing is allowed to pass
through the fluid controlling device, such that the at least one
pressure sensor measures the distal venous pressure, i.e., the
baseline absolute peripheral venous pressure from the vein only.
Following cuff-occlusion with a standard blood pressure cuff placed
proximal to the peripheral IV, a variety of hemodynamic data, such
as maximum PVP, rate of rise/slope of PVP, and rate of fall/slope
of PVP following cuff release, among other parameters, may be
obtained and analyzed.
[0100] In some embodiments, the apparatus further includes one or
more additional port device in fluid communication with the tubing
110. The one or more additional port device may be placed between
the fluid source 120 and the port device 140 or between the port
device 140 and the vein for measuring fluid pressures therein, such
as differential flows from the fluid source 120 and the PVP from
the vein, and for providing additional capability to input into and
or output from the fluid inside the tubing 110. In other words, the
at least one additional port device may be provided at any position
between the first end 112 and the second end 114 of the tubing 110,
and may be provided before or after the fluid controlling device
130. The one or more additional port device may be the T-piece
connector as shown in FIG. 1D, or the Y-piece connector as shown in
FIG. 1E.
[0101] FIG. 2 shows a flowchart of measuring PVP according to one
embodiment of the present invention. Specifically, the method
includes: providing a tubing operably connected between a fluid
source and a vein, a fluid controlling device in fluid
communication with the tubing, placed in the tubing and configured
to have an on position and an off position, and at least one
pressure sensor in fluid communication with the tubing, placed
between the fluid controlling device and the vein (step S210), and
then selectively passing fluid from the fluid source to the vein
through the tubing by the fluid controlling device (step S220).
When the fluid controlling device is in the on position, both a
fluid pressure from the fluid source and a distal venous pressure
from the vein are measured by the at least one pressure sensor
(step S230), and when the fluid controlling device is in the off
position, only the distal venous pressure from the vein is measured
by the at least one pressure sensor (step S240). The fluid pressure
and the distal venous pressure measured by the at least one
pressure sensor may be processed by a processor and displayed on a
display.
[0102] The advantages of the apparatus and method for measuring
peripheral venous pressure over the currently available
technologies include: eliminated need for invasive central venous
access; reduced vascular and thoracic complications; reduced
infection risk; point-of-care testing/portable and easy to use;
applicable to military and civilian trauma situations; minimal
training requirements; cost-effective; and more advance monitoring
capabilities compared to existing absolute PVP pressure monitoring
systems and methods, such as the technologies as disclosed in, for
example, WO 2003/001973 and WO 2010/045556, respectively.
[0103] Referring now to FIG. 3A, an apparatus for monitoring
intravascular placement of a peripheral IV catheter is shown
according to one embodiment of the present invention. The apparatus
300 is configured for detecting, among other things, proper
intravascular catheter placement within the vein in a non-invasive
manner, without the need for direct visualization of the IV site,
such as within the operating arena where the IV is obscured by the
sterile surgical drape. The apparatus 300 may be fixed or may be
portable for the convenience of the medical environments where the
system is utilized.
[0104] As shown in FIG. 3A, the apparatus 300 includes a tubing
310, a fluid source 320, a connector 330, first and second pressure
sensors 340 and 350, a circuit board 160, and a display 170.
[0105] The tubing 310 has a first end 312 and an opposite, second
end 314. The first end 312 is configured to be connected to the
fluid source 320, such as an IV bag, a saline bag, or other bags or
containers providing IV fluids. The second end 314 is connected to
the peripheral IV catheter 316, which in turn is placed in a vein
for performing IV therapy.
[0106] The tubing 310 has a narrow section between the first end
312 and the second end 314. The narrow section has an inner
diameter smaller than that of other part of the tubing 310. In this
embodiment, a connector 330, which includes the narrow section 332,
is in fluid communication with the tubing 310. As shown in an
enlarged view in FIG. 2B, the connector 330 has the narrow section
332 and first and second ports 334 and 336 on both sides of the
narrow section 332, and the narrow section 332 has an inner
diameter smaller than that of the tubing 310. The first and second
ports 334 and 336 may be standard luer lock connecting ports.
[0107] The first and second pressure sensors 340 and 350 are in
fluid communication with the tubing 310 through the first and
second ports 334 and 336 of the connector 330, respectively, and
are configured to measure fluid pressures therein. Thus, the two
pressure sensors 340 and 350 would be positioned on both sides of
the narrow section 332. In other words, the first pressure sensor
340 is positioned on a distal side of the narrow section 332 to the
IV catheter 316, and the second pressure sensor 350 is positioned
on a proximal side of the narrow section 332 to the IV catheter
316. Each of the first and second pressure sensors 340 and 350 may
include a pressure transducer, a pressure transmitter, a pressure
sender, a pressure indicator, a piezometer, or any other types of
pressure sensing or detecting devices or elements.
[0108] A processor is electrically coupled with the first and
second pressure sensors 340 and 350 for processing the measured
fluid pressures by the first and second pressure sensors 340 and
350. In this embodiment, the processor is associated with the
circuit board 360 of data acquisition and process, and a display
370 is in communication with the processor on the circuit board 360
for displaying the processed fluid pressures. The circuit board 360
may include standard computer input/output ports, such as USB
ports, for further data analysis. The display 370 may include a
graphic interface, such as a screen, or any other types of graphic
information output devices. The display 370 may be color, waveform,
or numerical to indicate IV position. Communication between the
sensor and the display may be remotely transmitted via Bluetooth or
radiofrequency mechanisms.
[0109] In operation, when fluid passes from the fluid source 320 to
the IV catheter 316 through the connector 330, a pressure drop of
the fluid is generated at the narrow section 332 due to the smaller
inner diameter of the narrow section 332. Thus, the first pressure
sensor 340 measures the higher-pressure flow before the narrow
section 332, and the second pressure sensor 350 measures the
lower-pressure flow after the narrow section 332. In other words,
the pressure drop is measureable by the first and second pressure
sensors 340 and 350. The pressure drop can be used for calculating
by slope and derivative of rate of fall of pressure, i.e., a
pressure change rate dP/dt.
[0110] In a low pressure venous system, measurements in patients
with a properly placed IV catheter 316 will display a pressure drop
with a constant or increasing pressure change rate dP/dt. In
contrast, if the IV catheter 316 is malpositioned or misplaced,
such as in the subcutaneous tissue, there will be a decreased or
absent pressure change rate dP/dt, which can provide a reading or
signal to the user or operator for correcting the misplacement. In
other words, the IV catheter 316 is properly placed when the
pressure change rate dP/dt is substantially constant or increases,
and the IV catheter 316 is not properly placed when the pressure
change rate dP/dt is substantially absent or decreases.
[0111] In one embodiment, the apparatus 300 may further include one
or more additional port device in fluid communication with the
tubing 310. The one or more additional port device may be placed
between the fluid source 320 and the connector 330 or between the
connector 330 and the vein for measuring fluid pressures
therein.
[0112] FIG. 4 shows a flowchart of monitoring intravascular
placement of a peripheral IV catheter according to one embodiment
of the present invention. Specifically, the method includes:
providing a tubing having a first end connected to a fluid source,
and an opposite, second end connected to the peripheral IV catheter
that in turn is placed in a vein, wherein the tubing is configured
to have a narrow section between the first and second ends, wherein
the narrow section has an inner diameter smaller than that of other
part of the tubing (step S410), and passing fluid from the fluid
source to the vein through the tubing (step S420). A pressure drop
at the narrow section is then measured by first and second pressure
sensors placed on both sides of the narrow section of the tubing
(step S430), and then whether the IV catheter is properly placed is
determined according to a pressure change rate dP/dt of the
pressure drop (step S440). In one embodiment, the determination
results as to whether the IV catheter is properly placed may be
displayed on a display.
[0113] In one aspect, the present invention also relates to a
method that utilizes a single pressure sensors/transducer without
needing a pressure differential or controlling fluid rate/turning
fluids off, etc. to monitor intravascular placement of a peripheral
IV catheter. Practically, the pressure sensors/transducer is still
placed between the fluid source and the IV. As such, measured
pressure and waveform data can be analyzed/processed while the
fluids are actively running into the IV.
[0114] In one embodiment, the method includes, among other things,
providing a tubing having a first end connected to a fluid source,
and an opposite, second end connected to the peripheral IV catheter
that in turn is placed in a vein, where the tubing may or may not
have a narrow section between the first and second ends, and a
pressure sensor in fluid communication with the tubing, placed
between the fluid source and the IV catheter, passing fluid from
the fluid source to the vein through the tubing, measuring
pressures of the fluid in the tubing by the pressure sensor, and
determining an IV position or intravascular location of the IV
catheter according to an algorithm in which the measured pressures
are processed.
[0115] The algorithm is based on analyzing waveforms of the
measured pressures to include mean pressure, integral of waveform,
variance, standard deviation, slope, sum of squares, correlation
along a straight line, and changes or delta of any of these
variables. The variables are measured, recorded, and compared over
pre-determined time intervals to determine IV position.
Accordingly, these data do not require a pressure differential.
Thus, only one pressure sensor is needed between the fluid source
and the IV, and the data is collected while the fluid source is
running thru the tubing into the IV.
[0116] The method may further include displaying the determined IV
position or intravascular location of the IV catheter on a display.
The display may be color, waveform, or numerical to indicate IV
position. Communication between the sensor and the display module
may be remotely transmitted via Bluetooth or radiofrequency
mechanisms.
[0117] The advantages of the apparatus and method for monitoring
intravascular placement of a peripheral IV catheter according to
various embodiments of the present invention include a measureable
pressure drop resulted in the narrow section between the pressure
sensors, and continuous monitoring across pressure drop, even with
intravascular fluids running. An algorithm based on statistical
analysis of the waveform and numerical data to include mean and
absolute pressure, integral, variance, standard deviation, slope,
sum of squares, correlation along a straight line, and changes or
delta of any of these variables. The result may be displayed
graphically, numerically, or color coded for proper IV placement.
For example, a display of green color may be used for proper
intravascular placement, and a red sign may be used for checking
for malpositioned or occluded intravascular catheter.
[0118] The apparatuses and methods as disclosed in the
aforementioned embodiments are capable of being utilized in
potential connections within the same system. In such a combined
system, a fluid controlling device such as a stopcock is utilized
to operate the apparatus with an on position and an off position to
statistically analyze absolute and changes in venous pressures,
venous pressure waveform or the combination of these waveforms with
fluids actively flowing through. A high mean pressure (>40 mmHg)
or change in pressure for example may alert to IV catheter kinking,
occlusion, misplacement or malpositioning. Simultaneous or combined
measurements of the fluid source and the venous pressure waveform
from the IV may determine without the need for the pressure drop
across a narrow section, but with measurement of a single area or
multiple areas along the tubing.
[0119] The foregoing description of the exemplary embodiments of
the invention has been presented only for the purposes of
illustration and description and is not intended to be exhaustive
or to limit the invention to the precise forms disclosed. Many
modifications and variations are possible in light of the above
teaching.
[0120] The embodiments were chosen and described in order to
explain the principles of the invention and their practical
application so as to activate others skilled in the art to utilize
the invention and various embodiments and with various
modifications as are suited to the particular use contemplated.
Alternative embodiments will become apparent to those skilled in
the art to which the present invention pertains without departing
from its spirit and scope. For example, multiple probes may be
utilized at the same time to practice the present invention.
Accordingly, the scope of the present invention is defined by the
appended claims rather than the foregoing description and the
exemplary embodiments described therein.
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