U.S. patent application number 14/954770 was filed with the patent office on 2016-05-12 for syringe and optical reader for syringe.
The applicant listed for this patent is Klein Medical Limited. Invention is credited to Kees Cornelis Klein.
Application Number | 20160131572 14/954770 |
Document ID | / |
Family ID | 38092474 |
Filed Date | 2016-05-12 |
United States Patent
Application |
20160131572 |
Kind Code |
A1 |
Klein; Kees Cornelis |
May 12, 2016 |
Syringe and Optical Reader for Syringe
Abstract
The present invention relates to a syringe (1) for use in
spectroscopy to identify drugs within the syringe (8). The syringe
comprises a optical window section (8) either integral with or
attached to the syringe (1). The optical window section (8) has
predetermined physical and optical properties that allows radiation
to pass through in a known manner to facilitate spectroscopy.
Inventors: |
Klein; Kees Cornelis;
(Auckland, NZ) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Klein Medical Limited |
Auckland |
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NZ |
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|
Family ID: |
38092474 |
Appl. No.: |
14/954770 |
Filed: |
November 30, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13915087 |
Jun 11, 2013 |
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14954770 |
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13299433 |
Nov 18, 2011 |
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13915087 |
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11564365 |
Nov 29, 2006 |
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13299433 |
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11564348 |
Nov 29, 2006 |
8512279 |
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11564365 |
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Current U.S.
Class: |
222/154 |
Current CPC
Class: |
A61M 5/1412 20130101;
G01N 21/01 20130101; A61M 2209/02 20130101; A61M 5/3129 20130101;
G01N 21/11 20130101; G01N 2201/068 20130101; A61M 5/31
20130101 |
International
Class: |
G01N 21/01 20060101
G01N021/01; A61M 5/14 20060101 A61M005/14; A61M 5/31 20060101
A61M005/31 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 29, 2005 |
NZ |
543876 |
Claims
1. A liquid delivery device adapted to deliver a liquid drug to a
patient or animal, the device comprising: a reservoir adapted to
contain the liquid drug to be delivered, the reservoir having an
outlet through which the liquid drug may be dispensed, a liquid
dispenser that causes a movement of the liquid drug from the
reservoir to and out of the outlet, and an optical window section,
for liquid drug, having predetermined optical and physical
properties that allows radiation to pass therethrough in a known
manner into an interior of the optical window section, and that
allows radiation affected by a content of the reservoir to pass
through as the affected radiation leaves the interior of the
window, wherein the optical window section: is attachable to the
reservoir such that the interior of the optical window section is
in fluid communication with the reservoir via the outlet, such that
liquid drug within the reservoir can be expelled into the interior
of the optical window section, comprises at least two parallel
planar panels that are at least partially transparent to radiation
and are configured to dock in the recess of a holder to enable
analysis of liquid drug therein, and comprises an outlet through
which expelled liquid drug can escape.
2. A liquid delivery device according to claim 1 wherein the device
is a syringe.
3. A liquid delivery device according to claim 2 wherein the device
is an IV administration set.
4. An IV administration set comprising: a reservoir adapted to
contain the liquid drug to be delivered, the reservoir having an
outlet through which the liquid drug may be dispensed, and an
optical window section, for liquid drug, having predetermined
optical and physical properties that allows radiation to pass
therethrough in a known manner into an interior of the optical
window section, and that allows radiation affected by a content of
the reservoir to pass through as the affected radiation leaves the
interior of the window, wherein the optical window section: is
attachable to the IV administration set such that the interior of
the optical window section is in fluid communication with the
reservoir via the outlet, such that liquid drug within the
reservoir can be expelled into the interior of the optical window
section, comprises at least two parallel planar panels that are at
least partially transparent to radiation and configured to dock in
the recess of a holder to enable analysis of liquid drug therein,
and comprises an outlet through which expelled drug can escape.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/915,087, filed Jun. 11, 2013, which is a
continuation of U.S. patent application Ser. No. 13/299,433, filed
on Nov. 18, 2011, which is a continuation of U.S. patent
application Ser. No. 11/564,365, filed on Nov. 29, 2006, which
claimed priority to New Zealand Patent Application No. 543876,
filed Nov. 29, 2005; and is a continuation of U.S. patent
application Ser. No. 11/564,348, filed on Nov. 29, 2006, which also
claimed priority to New Zealand Patent Application No. 543876,
filed Nov. 29, 2005.
FIELD OF THE INVENTION
[0002] This invention relates to liquid drug delivery devices which
prevent or minimise adverse drug events and in particular though
not solely to syringes adapted for allowing qualitative and/or
quantitative monitoring of their contents.
BACKGROUND TO THE INVENTION
[0003] Adverse drug events (ADEs) which are caused by the
administration to a patient of intravenous medications of incorrect
types, concentrations or dosages may cause irreparable damage or
even death in a patient. These types of ADE are entirely
preventable and attempts have been made to minimise or avoid their
occurrence. An example ADE prevention system is disclosed in U.S.
Pat. No. 6,847,899B. In this document plastic tubing forming part
of an IV administration set between an IV bag containing a drug to
be administered and a needle in a patient's arm is passed through a
spectroscopic analyser. The analyser is capable of determining both
the type of drug present in the tubing and its concentration. A
comparison may be made with expected results from the intended drug
type and concentration and a decision made on whether to allow an
infusion to continue.
[0004] In the above described system, variation in the positioning
of the tubing within the spectroscopic analyser and variation in
the physical and optical properties of the tubing itself will
affect the outcome of the analysis. Furthermore, an IV
administration set is often used to transport more than one type of
drug, at different times, to the patient. Contamination of the
tubing with multiple drug types reduces the ability of the
spectroscopic analyser to determine the type of drug currently
present.
SUMMARY OF THE INVENTION
[0005] Accordingly, it is an object of the present invention to
provide a liquid delivery device and/or a docking station for a
liquid delivery device which will go at least some way towards
overcoming the above disadvantages or which will at least provide
the industry with a useful choice.
[0006] In one aspect the present invention may be said to consist
in a liquid delivery device adapted to deliver a liquid drug to a
patient or animal comprising: a reservoir adapted to contain liquid
drug to be delivered, the reservoir having an outlet through which
liquid drug may be dispensed, a liquid dispensing which causes a
movement of the liquid drug from the reservoir to and out of the
outlet, wherein the reservoir comprises an optical window section
having predetermined optical and physical properties that allows
radiation to pass therethrough in a known manner into the interior
of the reservoir and that allows radiation affected by the content
of the reservoir to pass through as the affected radiation leaves
the interior of the reservoir.
[0007] Preferably the predetermined optical properties comprise
optical density and clarity.
[0008] Preferably the predetermined physical properties comprise
the thickness and slope and curvature of the reservoir wall in the
optical window section.
[0009] Preferably the optical window section is provided adjacent
to the outlet.
[0010] Preferably the optical window section comprises the
outlet.
[0011] Preferably the reservoir is substantially cylindrical and
the optical window section caps the reservoir and comprises the
outlet.
[0012] Preferably the optical window section is formed separately
from the remainder of the reservoir and is attached and sealed
thereto in a separate process.
[0013] Preferably the optical window section is formed as part of
the reservoir in a single process.
[0014] Preferably the optical window section is formed from a
material which is different from the material from which the
remainder of the reservoir is formed.
[0015] Preferably the optical window section comprises a transition
portion between the reservoir and the outlet wherein the outlet has
a smaller diameter than the diameter of the reservoir and wherein
the optical window is provided in the transition portion.
[0016] Preferably the optical window section comprises at least one
planar panel that is at least partially transparent to
radiation.
[0017] Preferably the optical window section comprises at least
four planar panels that are at least partially transparent to
radiation.
[0018] Preferably the device is adapted to engage in a docking
station, the docking station comprising a receptacle adapted to
receive the optical window section wherein the at least one planar
panel is adapted to be received in the receptacle against a
corresponding wall of the receptacle, the corresponding wall
preventing rotation of the optical window section received within
the receptacle.
[0019] Preferably the docking station comprises an optical input
for transmitting incident radiation to at least one of the planar
panels of the optical window section received in the receptacle,
and an optical output for transmitting radiation received from at
least one of the planar panels of the optical window section
received in the receptacle.
[0020] Preferably the optical window section comprises a protrusion
for engaging with a corresponding recess in the receptacle to
prevent rotation of the optical window section when received in the
receptacle.
[0021] Preferably the device further comprises optically readable
markings on the liquid dispenser and an optical reader with one or
more optical detectors arranged to detect the optically readable
markings, wherein the optical reader comprises a processor that
receives one or more signals from the one or more optical detectors
and generates position data indicating a position of the liquid
dispenser relative to the reservoir.
[0022] Preferably the processor generates quantity data indicating
a quantity of the liquid drug in the reservoir.
[0023] Preferably optical reader comprises a transmitter adapted to
wirelessly transmit the quantity data or position data to a
system.
[0024] Preferably the optical reader further comprises an energy
storage device for powering the optical reader, the energy storage
device coupled to an inductive device, the inductive device adapted
to inductively couple to an inductive recharging device to receive
energy for recharging the energy storage device.
[0025] In another aspect the present invention may be said to
consist in a liquid delivery device adapted to deliver a liquid
drug to a patient or animal comprising: a reservoir adapted to
contain liquid drug to be delivered, the reservoir having an outlet
through which liquid drug may be dispensed, a liquid dispenser that
causes a movement of the liquid drug from the reservoir to and out
of the outlet, and an optical window section having predetermined
optical and physical properties that allows radiation to pass
therethrough in a known manner into an interior of the optical
window section, and that allows radiation affected by a content of
the reservoir to pass through as the affected radiation leaves the
interior of the window, wherein the optical window section is
attached to the reservoir such that the interior of the optical
window section is in fluid communication with the reservoir via the
outlet, such that liquid within the reservoir can be expelled into
the interior of the optical window section.
[0026] Preferably the predetermined optical properties comprise
optical density and clarity.
[0027] Preferably the physical properties comprise the thickness
and slope and curvature of a reservoir wall in the optical window
section.
[0028] Preferably the optical window section is formed from a
material which is different from the material from which the
reservoir is formed.
[0029] Preferably the optical window section comprises at least one
planar panel that is at least partially transparent to
radiation.
[0030] Preferably the optical window section comprises at least
four planar panels that are at least partially transparent to
radiation.
[0031] Preferably the device is adapted to engage in a docking
station, the docking station comprising a receptacle adapted to
receive the optical window section wherein the at least one planar
panel is adapted to be received in the receptacle against a
corresponding wall of the receptacle, the corresponding wall
preventing rotation of the optical window section received within
the receptacle.
[0032] Preferably the docking station comprises an optical input
for transmitting incident radiation to at least one of the planar
panels of the optical window section received in the receptacle,
and an optical output for transmitting radiation received from at
least one of the planar panels of the optical window section
received in the receptacle.
[0033] Preferably the optical window section comprises a protrusion
for engaging with a corresponding recess in the receptacle to
prevent rotation of the optical window when received in the
receptacle.
[0034] Preferably the device further comprises optically readable
markings on the liquid dispenser and an optical reader with at
least one optical detector arranged to detect the optically
readable markings, wherein the optical reader comprises a processor
that receives one or more signals from the one or more optical
detectors and generates position data indicating the position of
the liquid dispenser relative to the reservoir.
[0035] Preferably wherein the processor generates quantity data
indicating a quantity of the liquid drug in the reservoir.
[0036] Preferably the optical reader comprises a transmitter
adapted to wirelessly transmit the quantity data or position data
to a system.
[0037] Preferably the optical reader further comprises an energy
storage device for powering the optical reader, the energy storage
device coupled to an inductive device, the inductive device adapted
to inductively couple to an inductive recharging device to receive
energy for recharging the energy storage device.
[0038] In another aspect the present invention may be said to
consist in an optical window section for attachment to a liquid
delivery device wherein the optical window section has
predetermined optical and physical properties that allows radiation
to pass therethrough in a known manner into an interior of the
optical window section and that allows radiation affected by a
content of the optical window section to pass through as the
affected radiation leaves the interior of the window.
[0039] In another aspect the present invention may be said to
consist in a liquid delivery device adapted to deliver a liquid
drug to a patient or animal comprising: a reservoir adapted to
contain liquid drug to be delivered, the reservoir having an outlet
through which liquid drug may be dispensed, a liquid dispenser
which causes a movement of the liquid drug from the reservoir to
and out of the outlet, and an optical window section coupled to the
reservoir, the optical window section having predetermined optical
and physical properties that allows radiation to pass therethrough
in a known manner into an interior of the optical window section
and that allows radiation affected by a content of the reservoir to
pass through as the affected radiation leaves the interior of the
optical window section, wherein the optical window section
comprises at least one planar panel that is at least partially
transparent to radiation.
[0040] Preferably the optical window section comprises at least
four planar panels that are at least partially transparent to
radiation.
[0041] Preferably the device is adapted to engage in a docking
station, the docking station comprising a receptacle adapted to
receive the optical window section wherein the at least one planar
panel is adapted to be received in the receptacle against a
corresponding wall of the receptacle, the corresponding wall
preventing rotation of the optical window section received within
the receptacle.
[0042] Preferably the docking station comprises an optical input
for transmitting incident radiation to at least one of the planar
panels of the optical window section received in the receptacle,
and an optical output for transmitting radiation received from at
least one of the planar panels of an optical window section
received in a receptacle.
[0043] Preferably the optical window section comprises a protrusion
for engaging with a corresponding recess in the receptacle to
prevent rotation of the optical window when received in the
receptacle.
[0044] Preferably the device further comprises optically readable
markings on the liquid dispenser and an optical reader with at
least one optical detector for detecting the optically readable
markings, wherein the optical reader comprises a processor that
receives one or more signals from the one or more optical detectors
and generates position data indicating a position of the liquid
dispenser relative to the reservoir.
[0045] Preferably the processor generates quantity data indicating
a quantity of the liquid drug in the reservoir.
[0046] Preferably the optical reader comprises a transmitter
adapted to wirelessly transmit the quantity data or position data
to a system.
[0047] Preferably the optical reader further comprises an energy
storage device coupled to an inductive device, the inductive device
adapted to inductively couple to an inductive recharging device to
receive energy for recharging the energy storage device.
[0048] In another aspect the present invention may be said to
consist in a docking station adapted to receive a liquid delivery
device adapted to deliver a liquid drug to a patient or animal, the
liquid delivery device comprising: a reservoir adapted to contain
the liquid drug to be delivered, the reservoir having an outlet
through which liquid drug may be dispensed, a liquid dispenser
which causes a movement of the liquid drug from the reservoir to
and out of the outlet, and an optical window section having
predetermined optical and physical properties that allows radiation
to pass therethrough in a known manner into an interior of the
optical window section and that allows radiation affected by a
content of the optical window section to pass through as the
affected radiation leaves the interior of the optical window
section, wherein the optical window section comprises at least one
planar panel, and wherein the docking station comprises: a
receptacle adapted to receive the optical window section of a
liquid delivery device wherein the at least one planar panel of the
optical window section is adapted to be received in the receptacle
against a corresponding wall of the receptacle, the corresponding
wall preventing rotation of the optical window section received
within the receptacle.
[0049] In another aspect the present invention may be said to
consist in a spectroscopic liquid analysis system comprising: a
liquid delivery device having a reservoir adapted to contain a
liquid drug to be delivered and an outlet through which the liquid
drug may be dispensed, and a liquid dispenser which causes movement
of the liquid from the reservoir to and out of the outlet, a
radiation source that generates radiation that is then directed at
a content of the reservoir, and a spectroscopic analyser configured
to receive radiation affected by the content of the reservoir and
to provide an indication of the composition of the content of the
reservoir based upon a spectrum of the received radiation.
[0050] Preferably the reservoir comprises an optical window section
having predetermined optical and physical properties that allows
radiation to pass therethrough in a known manner into an interior
of the reservoir and that allows radiation affected by a content of
the reservoir to pass through as the affected radiation leaves the
interior of the reservoir.
[0051] Preferably the liquid delivery device comprises an optical
window section coupled to the reservoir having predetermined
optical and physical properties that allows radiation to pass
therethrough in a known manner into an interior of the optical
window section and that allows radiation affected by a content of
the optical window section to pass through as the affected
radiation leaves the interior of the optical window section.
[0052] Preferably the liquid delivery device comprises a
syringe.
[0053] Preferably the system further comprises a docking station
adapted to receive the reservoir in the vicinity of the optical
window section.
[0054] Preferably the reservoir is substantially cylindrical and
the docking station comprises a substantially cylindrical sleeve
having a larger internal diameter than the external diameter of the
reservoir.
[0055] Preferably one opening in the sleeve is smaller than the
external diameter of the reservoir.
[0056] Preferably the radiation source transmits radiation through
an optical window in the docking station aligned in use with the
optical window section of the reservoir.
[0057] Preferably the radiation source transmits radiation directly
at the optical window section of the reservoir without first
passing through the docking station.
[0058] Preferably the system further comprises a docking station
wherein the docking station comprises a receptacle adapted to
receive an optical window section of the liquid delivery device
wherein the optical window section is formed from at least one
planar panel that is at least partially transparent to radiation
and wherein the at least one planar panel of the optical window
section is adapted to be received in the receptacle against a
corresponding wall of the receptacle, the corresponding wall
preventing rotation of the optical window section.
[0059] Preferably the radiation source produces electromagnetic
radiation which is transmitted to the docking station via an
optical fibre and electromagnetic radiation affected by the
contents of the reservoir is transmitted to the spectroscopic
analyser by a further optical fibre.
[0060] Preferably the optical fibres are terminated on the docking
station and are directed at the optical window section.
[0061] Preferably the reservoir is manufactured from a non-metallic
material and has provided thereon at least two separated conductive
sections, and a further comprising means for obtaining an
indication of the capacitance or inductive coupling between the two
conductive sections that thereby provide an indication of the
amount of liquid in the reservoir.
[0062] Preferably the system further comprises optically readable
markings on the liquid dispenser and an optical reader with at
least one optical detector for detecting the optically readable
markings, wherein the optical reader comprises a processor that
receives one or more signals from the one or more optical detectors
and generates position data indicating a position of the liquid
dispenser relative to the reservoir.
[0063] Preferably the processor generates quantity data indicating
a quantity of liquid in the reservoir.
[0064] Preferably the optical reader comprises a transmitter
adapted to wirelessly transmit the quantity data or position data
to a system.
[0065] Preferably the optical reader further comprises an energy
storage device coupled to an inductive device, the inductive device
adapted to inductively couple to an inductive recharging device to
receive energy for recharging the energy storage device. In this
specification where reference has been made to patent
specifications, other external documents, or other sources of
information, this is generally for the purpose of providing a
context for discussing the features of the invention. Unless
specifically stated otherwise, reference to such external documents
is not to be construed as an admission that such documents, or such
sources of information, in any jurisdiction, are prior art, or form
part of the common general knowledge in the art
[0066] In one aspect the present invention may be said to consist
in a liquid delivery device adapted to deliver a liquid drug to a
patient or animal comprising: a reservoir adapted to contain liquid
drug to be delivered, the reservoir having an outlet through which
liquid drug may be dispensed, a liquid dispenser with a
longitudinal axis which causes movement of the liquid drug from the
reservoir to and out of the outlet, the liquid dispenser comprising
optically readable markings disposed at a plurality of positions
along at least a portion of the longitudinal axis,
[0067] an optical reader comprising at least one optical detector
arranged to detect the optically readable markings, each optical
detector adapted to provide an output signal indicative of one or
more detected optically readable markings, and a processor coupled
to receive the output signal and generate position data indicating
a position of the liquid dispenser relative to the reservoir.
[0068] Preferably the processor generates quantity data indicating
a quantity of liquid drug in the reservoir.
[0069] Preferably the optically readable markings comprise a
plurality of indicia positioned in a sequence along at least a
portion of the longitudinal axis of the liquid dispenser, and
wherein the processor generates the position data by counting the
number of indicia detected by the optical detector as the liquid
dispenser is moved relative to the optical detector.
[0070] Preferably the optical reader comprises at least two optical
detectors arranged to detect the indicia, wherein the optical
detectors are positioned at a relative separation to provide
quadrature encoding signals that can be used by the processor to
generate the position data and direction data indicating the
direction in which the liquid dispenser is moved relative to the
optical detector.
[0071] Preferably the position data is indicative of the quantity
of liquid within the reservoir.
[0072] Preferably the optical reader comprises a transmitter
adapted to wirelessly transmit the quantity data or position data
to a system.
[0073] Preferably the optical reader is detachable from the liquid
delivery device.
[0074] Preferably the optical reader further comprises an energy
storage device coupled to an inductive device, the inductive device
adapted to inductively couple to an inductive recharging device to
receive energy for recharging the energy storage device.
[0075] In another aspect the present invention may be said to
consist in an optical reader adapted to couple to a liquid delivery
device and generate position data indicative of the position of a
liquid delivery means of the liquid delivery device, the optical
reader comprising: a coupling for attachment to a liquid delivery
device, at least one optical detector arranged to detect optically
readable markings on a liquid delivery means, each optical reader
adapted to provide an output signal indicative of one or more
detected optically readable markings, and a processor coupled to
receive the output signal and generate position data indicating a
position of the liquid dispenser relative to the reservoir.
[0076] Preferably the processor generates quantity data indicating
a quantity of the liquid drug in the reservoir.
[0077] Preferably the optically readable markings comprise a
plurality of indicia positioned in a sequence along at least a
portion of a longitudinal axis of the liquid dispenser, and wherein
the processor can generate the position data by counting the number
of indicia detected by the optical detector as the liquid dispenser
is moved relative to the optical detector.
[0078] Preferably the optical reader comprises at least two optical
detectors arranged to detect the indicia, wherein the optical
detectors are positioned at a relative separation to provide
quadrature encoding signals that can be used by the processor to
generate the position data and direction data indicating the
direction in which the liquid dispenser is moved relative to the
optical detector.
[0079] Preferably the position data is indicative of a quantity of
liquid within the reservoir.
[0080] Preferably the reader further comprises a transmitter
adapted to wirelessly transmit the quantity data or position data
to a system.
[0081] Preferably the optical reader further comprises an energy
storage device coupled to an inductive device, the inductive device
adapted to inductively couple to an inductive recharging device to
receive energy for recharging the energy storage device.
[0082] In this specification where reference has been made to
patent specifications, other external documents, or other sources
of information, this is generally for the purpose of providing a
context for discussing the features of the invention. Unless
specifically stated otherwise, reference to such external documents
is not to be construed as an admission that such documents, or such
sources of information, in any jurisdiction, are prior art, or form
part of the common general knowledge in the art
[0083] The term "comprising" as used in this specification means
"consisting at least in part of". Related terms such as "comprise"
and "comprised" are to be interpreted in the same manner.
[0084] To those skilled in the art to which the invention relates,
many changes in construction and widely differing embodiments and
applications of the invention will suggest themselves without
departing from the scope of the invention as defined in the
appended claims. The disclosures and the descriptions herein are
purely illustrative and are not intended to be in any sense
limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] FIG. 1 is a perspective view of a syringe in accordance with
a first embodiment of the invention,
[0086] FIG. 2 is a cross-sectional view of the optical window
section of the syringe of FIG. 1 showing its use in reflectance
mode spectroscopy,
[0087] FIG. 3 is a cross-sectional view of the optical window
section of the syringe of FIG. 1 showing its use in transmission
mode spectroscopy,
[0088] FIG. 4 is a perspective view of a docking station or sleeve
adapted to receive the syringe of FIG. 1 in order to allow
spectroscopic analysis on the contents of the syringe to occur,
[0089] FIG. 5 is a side elevation of the syringe of FIG. 1 within
the docking station of FIG. 4,
[0090] FIG. 6 is a perspective view of a syringe which also
includes a mechanism for determining the amount of liquid within
the syringe,
[0091] FIG. 7 is a schematic block diagram of a spectroscopic
analysis system including the syringe of FIGS. 1 and/or 6,
[0092] FIG. 8 is a perspective view of a syringe in accordance with
a second embodiment of the invention,
[0093] FIGS. 9a, 9b, and 9c are plan views of two optical window
sections of the second embodiment,
[0094] FIGS. 10a-10c are various views of the syringe docked in a
docking station,
[0095] FIGS. 11a, 11b are plan views of the optical window docked
in recess of the docking station,
[0096] FIGS. 12a, 12b are perspective views of an optical reader
adapted for attachment to the syringe,
[0097] FIG. 13 is a plan view showing the optical reader attached
to the syringe,
[0098] FIG. 14 is a schematic diagram of a qualitative and
quantitative analysis system incorporating the syringe,
[0099] FIGS. 15a, 15b show the syringe markings and photodetectors
in more detail,
[0100] FIG. 16 is a circuit diagram of one embodiment of the
inductive charger, and
[0101] FIG. 17 is a circuit diagram of one embodiment of the
quadrature detectors for the optical reader.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
First Embodiment
[0102] With reference to the drawings and in particular FIG. 1, a
syringe 1 is shown having a reservoir portion 2 and a liquid
dispenser or liquid dispensing means, such as a plunger 3. Although
the invention is being described with reference to a syringe it
should be noted that the invention is equally applicable to other
types of liquid delivery devices which includes a piston and
cylinder arrangement such as animal drench guns or oral dosing
systems for animal use.
[0103] The syringe's plunger 3 slides within the reservoir 2 as a
piston slides within a cylinder, to evacuate the contents of the
reservoir through an outlet 4. The outlet may be provided with a
needle fitting (not shown) for intravenous delivery of the content
of the reservoir to a patient. Alternatively, as shown, an outlet
fitting 11 such as a well known "luer lock" or "luer slip" fitting
may be provided at the outlet of the reservoir. These fittings
allow for twist lock or press fit engagement with a complimentary
fitting on an inlet of a luer forming part of in IV administration
set connected to an indwelling vein access device (such as a needle
or cannula) inserted in a patient. Alternatively, the luer may
simply be connected by tubing to a patient's indwelling vein access
device (not shown).
[0104] As is well known, plunger 3 is provided with a rubber or
elastomeric head 5 which is a tight fit within the substantially
cylindrically shaped reservoir 2 and which forms a seal with the
inner wall thereof. The end of plunger 3 furthest from the
reservoir is provided with a flange 6 adapted to be pressed by a
user's thumb whilst the user's first and second fingers are
positioned beneath a flange 7 at the open end of reservoir 2. In
use, as is well known, a user presses flange 6 with his or her
thumb whilst pulling flange 7 with the first and second fingers to
cause liquid within the reservoir to be dispensed from outlet 4.
The syringe may be pre-loaded with liquid or can be filled via the
outlet 4 in the known way.
[0105] Reservoir 2 is preferably transparent or translucent so that
a user is able to determine the amount of liquid, such as a liquid
drug, held therein. Reservoir 2 may be formed from a medical grade
plastics or glass material such as HDPE for example. Reservoir 2
includes an optical window section 8 which is preferably formed
from a different material to the remainder of the reservoir 2. The
material from which the optical window section 8 is manufactured is
a high quality plastics or glass with close manufacturing
tolerances for both its physical and optical properties. Suitable
exemplary materials from which the optical window may be made
include cast or extruded Acrylic plastics, Polycarbonate plastics
(such as LEXAN.RTM. manufactured by GE Plastics), Butyrate
plastics, polypropylene and Clear PVC.
[0106] In terms of the controlled physical properties, one or more
of the thickness, slope and curvature of the optical window section
should be within predetermined ranges. The material chosen for the
optical window should have low distortion properties, no or minimal
fading, shrinking lines or optical distortion. Flatness is also
important as is the ability to reproduce wall thickness and, for
use in a transmission mode spectroscopic system, wall separation.
The wall thickness may range from about 0.6 mm to about 1.2 mm and
could be 1 mm. The wall separation (the distance between the wall
surface through which light enters and the surface where affected
light enters the sensor opposite) may range from about 8 mm to
about 12 mm, and preferably around 10 mm. Preferably, the
predetermined optical characteristics include the optical density
and clarity of the optical window section. Importantly, the
material chosen for the optical window should be substantially
transparent with low absorbance, preferably a low absorbance
particularly in the near infra-red range. Polycarbonate plastics
may therefore be especially suitable.
[0107] The optical window section 8 is shown in more detail in
FIGS. 2 and 3 in schematic form. The optical window section
includes a substantially cylindrical wall section 9, a transition
section 10 and an outlet fitting section 11 in which the outlet 4
is formed. Preferably, the entire optical window section 8 is
formed from a single homogeneous material which is connected or
bonded or sealed to the remaining, open-ended portion of the
reservoir 2 during manufacture of the reservoir.
[0108] The syringe according to the present invention is adapted to
be used in conjunction with a qualitative analysis device such as a
spectroscopic analyser to determine the composition of material
within the reservoir 2. Accordingly, optical window section 8 is
manufactured within known optical and physical tolerances so that
it has a known affect on radiation passing therethrough. The
optical window section 8 will therefore cause a known reduction in
light intensity at known frequencies and this effect can be
factored in to calculations carried out by the spectroscopic
analyser. The spectroscopic analyser may then determine an accurate
spectroscopic "fingerprint" of the liquid within reservoir 2 for
comparison with spectroscopic data of known drugs. In this way, as
a drug is being administered to a patient by the syringe or just
prior to delivery of a drug using the syringe, it is possible to
check that the drug being delivered is that which is intended to
thereby avoid or reduce the risk of an adverse drug event.
[0109] As shown in FIG. 2, reflectance mode spectroscopic analysis
may be carried out on the syringe by causing light, for example in
the near-infrared (NIR) spectrum, to be incident on the optical
window section 8. The incident light will be transmitted through
the optical window section while being effected by the optical
window section in a known way, interact with the contents within
receptacle 2 and then some of the incident light will be reflected
back (as shown by the arrows) through the optical window section to
a detector having been affected in a known way as it travels back
through the optical window section. Incident light is preferably
directed at the transition section 10. The piston should not be
fully depressed as it may interfere with the light path through the
liquid. The minimum clearance between the end of the plunger and
the wall of the transition section of the optical window depends
upon the choice of plastics or glass material, the width of the
light beam, the angles of incidence and reflection and, in the case
of a system with a lens, the position of the focal point within the
syringe. As an example, the minimum clearance may be less than
about 5 mm.
[0110] Any suitable method of spectroscopic analysis could be used,
for example the system disclosed in our PCT application published
as WO 2004/025233A. FTIR (Fourier Transform Infra-Red spectroscopic
analysis), Raman scattering, UV/VIS (ultra-violet/visible) and
infra-red methods could also be employed. Some modes of magnetic
resonance and low power radioactive radiation could also be used to
determine the composition of the liquid within the receptacle.
[0111] Alternatively, as shown in FIG. 3, transmission mode
spectroscopy could be employed to determine the composition of the
contents of the reservoir. For example, as shown in FIG. 3,
radiation such as light from a radiation source may be directed
through the luer fitting 11, the walls of which will have a known
affect on the transmission of the radiation both into and out of
the optical window section.
[0112] Although not shown, outlet 4 may include a valve to retain
liquid in the receptacle until plunger 3 is pushed. The diameter
and roundness of the substantially cylindrical outlet fitting
section 11 is also manufactured to strict tolerances and therefore
the path length of the radiation travelling through the contents of
the reservoir is accurately known which is of course essential for
transmission mode spectroscopic analysis. In this way, measurements
are made repeatable so that useful comparisons and/or calibration
can be performed. Alternatively, the substantially cylindrical
outlet fitting section 11 could be provided with one or more flat
sides or could be square or rectangular in cross-section. This may
however require additional means to orient the syringe within
housing 12 to ensure that the incident light beam is directed
substantially normal to a flattened face of the outlet fitting.
[0113] FIG. 4 shows a housing 12 adapted to receive syringe 1 to
enable spectroscopic analysis of the syringe's contents to be
carried out. Housing 12 forms a substantially cylindrical docking
station or holder for the syringe. Housing 12 has an open first end
13 adapted to receive the reservoir 2 and a second open end 14
having a smaller opening through which outlet fitting 11 may, in
use, protrude. Flanges 15 at the first end of the housing form a
seat for reservoir flanges 7 when the reservoir is positioned
appropriately within the housing. An annular conical ring section
15a forms an optical window in the holder which, in use, is aligned
with the transition section 10 of the reservoir's optical window 8.
The physical and optical properties of at least the housing's
optical window section are specified and controlled during
manufacture in a similar manner to the properties of optical window
section 8 of reservoir 2.
[0114] To enable the combination liquid delivery device (or
syringe) and housing according to the invention to remain as
compact and lightweight and as possible, it is preferred that the
spectroscopic analyser is positioned remotely. Accordingly, the
spectroscopic analyser 16 including radiation source 17 shown in
FIG. 4 is connected to housing 12 by optical fibres 18 and 19
having terminations 20 and 21 respectively on the housing.
Terminations 20 and 21 ensure that the ends of the fibres are
coupled to the optical window 15a of the housing to receive or
transmit radiation in appropriate directions. As an example, the
incident and reflected beams may have an angle of about 30.degree.
between them.
[0115] Dependent upon the type of radiation used, other
transmission mediums could be used. Alternatively, the radiation
source, such as a light emitting diode (LED) could be mounted on
the housing and controlled via a wired or wireless connection to
the spectrum analyser.
[0116] As shown in FIG. 5, housing 12 could be built into a tray or
cabinet or other larger fixture. In this case, the spectrum
analyser may also be built into that larger fixture. Furthermore,
rather than requiring optical fibres to connect the housing to the
spectroscopic analyser, light beams with any necessary lens system
could be transmitted through an air path to and/or from the
reservoir.
[0117] FIG. 5 also shows a further aspect of the invention wherein
the syringe is capable of quantitative analysis of the syringe's
contents. This may be in conjunction with the spectroscopic
qualitative analysis described above or may be independent thereof.
The quantitative analysis is provided by electrically conductive
segments 23 and 24 on reservoir 2. In the example shown where the
liquid delivery device constitutes a syringe, conductive segments
23 and 24 may be located substantially on opposite sides of the
longitudinal axis of the reservoir extending axially substantially
the entire length (or a substantial portion thereof) of the
reservoir. The conductive segments may be formed as electrodes from
a layer of conductive foil such as aluminium or copper.
Alternatively, the conductive layers may be formed from a
conductive plastics material or a plastics material that is doped
with a conductive agent such as graphite or a metallic
compound.
[0118] The two conductive electrodes form the plates of a
capacitor. The dielectric constant of the material from which the
wall(s) of the reservoir are formed or air is significantly
different to the dielectric constant of the (often water-based)
liquid drugs inside the reservoir of the syringe. As an example, a
conventional 10 mL disposable plastics syringe will change
capacitance from a few picofarads to tens of picofarads from empty
to full of a water-based drug. These amounts obviously depend upon
the size of the electrodes and the dimensions of the syringe.
[0119] Displacement of plunger 3 within reservoir 2 causes liquid
within the reservoir to exit via outlet 4. The capacitance of the
capacitor formed by the electrodes and air/liquid/plastics material
therebetween to vary as a result. It has been found that the
capacitance of the capacitor varies substantially proportionally to
the amount of fluid remaining inside the reservoir. By carrying out
experiments with various different liquid drugs, it is possible to
develop mathematical relationships or a lookup table relating
capacitance (or an indicator thereof) and the amount of fluid in
the reservoir. Therefore, by simply determining the capacitance of
the capacitor formed by the electrodes printed or applied to the
surface or within the wall of the reservoir, it is possible to
calculate the amount of fluid remaining in the reservoir. During a
continuous time measurement when liquid is being evacuated from the
reservoir, the flow rate of the liquid can easily be
calculated.
[0120] In an alternative (or in addition) to electrodes forming the
electrically conductive segments 23 and 24, coils could be provided
on either side of the reservoir. The coils could be etched onto the
sides of the reservoir or could be provided on adhesive labels for
example. It has been found that the inductive coupling (or mutual
inductance) between the two coils is substantially directly
proportional to the amount of liquid remaining in the
reservoir.
[0121] In either the capacitive or inductive situations, the beat
frequency or phase shift of a tuned circuit may be used to
determine the capacitance or inductive coupling between the
conductive sections. An electronic circuit providing a high
frequency oscillating voltage or current to an LC resonant tank
circuit including the reservoir capacitor or inductors could be
tuned to a particular resonant frequency when the reservoir is
empty. The tuned circuit will be de-tuned as a result of the liquid
within the reservoir and this change in resonant frequency can be
detected and used to calculate capacitance or inductive coupling.
The frequency or phase shift caused by the change may also be
directly proportional to the amount of liquid between the capacitor
plates or coils. The effect of the liquid on radio frequency
transmission from an aerial positioned on the wall of the reservoir
could also be used to achieve the same effect In the case of a
capacitive circuit, the electronic detector circuit may include a
circuit that is tuned to detect the charge and/or discharge of an
external capacitor formed by the capacitor plates and the liquid. A
regular pulse train of current in the form of a square wave (of
less than 100 kHz for example) may be supplied to the capacitor and
the charge and/or discharge time of the unknown capacitor used as
an indicator of, or to determine its, capacitance. Alternatively, a
comparator circuit could determine the time taken for the voltage
across the unknown capacitor to reach a predetermined value and
this could provide an indication of capacitance.
[0122] The conductive sections 23 and 24, whether electrodes or
coils, require conductive terminations which could be provided near
the top of reservoir 2. The conductive terminations are connected
to an electronic circuit capable of determining capacitance or
inductive coupling or an indication thereof or changes in one of
these parameters. Alternatively, raw detected values could be
transmitted to a remote device at which analysis to determine
capacitance or inductive coupling or an indication of one of these
parameters is conducted. The electronic circuit may include an
electronic controller executing software which inputs an indication
of capacitance or inductive coupling via an analogue to digital
converter, analogue comparator or pulse sensing logic circuit for
example. The electronic circuit could conveniently be mounted on or
to syringe 1 or housing 12 with connections to the conductive
terminations.
[0123] Alternatively, as shown in FIG. 6, a separate housing or
sleeve 25 may be provided about reservoir 2 which houses the
electronic sensing circuit 26 (shown schematically) and includes
contacts which mate with the electrical terminations on the surface
of reservoir 2 (circuit 26 is shown connected to conductor section
24 only as conductor section 23 is hidden from view). Note that
sleeve 25 has not been shown in FIG. 5 for clarity purposes only.
Sleeve 25 may require a power source such as a small battery and
would preferably include a transmitter (and optionally a receiver
or transceiver) to allow short range transmission of radio
frequency signals (using the BLUETOOTH.RTM. protocol for example).
Sleeve 25 may be formed as a ring or torus for example which has an
internal diameter which is a sliding fit about reservoir 2. The
reservoir 2 of the syringe could then be slid into the ring until
the ring reaches its operative position with the conductive
terminations of the electrical sections 23 and 24 connecting with
contacts on the internal surface of the ring. The operative
position may correspond with sleeve 25 contacting flange 7 of the
reservoir so that the user may use sleeve 25 as finger supports
rather than flange 7 during use of the syringe. Once in the
operative position, the sleeve may simply remain there through a
tight fit or could be bonded or welded into place.
[0124] Alternatively, rather than being subsequently mounted to the
syringe, sleeve 25 may be formed integrally with the reservoir.
[0125] The electronic circuit within sleeve 25 could also include a
memory device such as an EEPROM (Electrically Erasable Programmable
Read-Only Memory) for storing data pertinent to the
syringe/reservoir and/or the intended content of the syringe. For
example, one or more of the following data fields could be stored
in the memory device: [0126] a unique identifier for the
syringe/reservoir, [0127] an identifier of the type of drug
intended to be used with the syringe, [0128] the capacitance or
inductive coupling value associated with the reservoir when empty,
[0129] the expected capacitance or inductive coupling when the
syringe is fully loaded, [0130] calibration information or lookup
table(s) to allow detected capacitance/inductance data to be
accurately transformed into a remaining volume value, and [0131] a
spectroscopic fingerprint of the expected content of the reservoir
for cross-checking purposes (that is, spectrum data for comparing
with the output from the spectroscopic analyser to determine
whether the composition of syringe's contents is as expected.
[0132] This data or portions of it along with capacitance or
inductive coupling data (or data indicative thereof) could be
transmitted to a remote receiving device connected to a system
controller 27 as shown in FIG. 7 that executes software
instructions. The system controller is connected to the
spectroscopic analyser 16 and an output device such as a display 28
unit and/or an audio device such as a speaker 29. System controller
27 receives spectrum data from the spectroscopic analyser and may
compare this determined data with stored "fingerprint" data for
known liquid drugs to determine a best match drug. The display unit
28 and/or speaker 29 may then provide visual and/or audible
information to a user of the drug which most closely matches the
contents of the reservoir. Alternatively, the display device 28
could output a graphical display of the drug's photometric spectrum
for review by the user.
[0133] If memory device within sleeve 25 is provided with data on
the expected content of the syringe or a cross-check fingerprint
then this data may also be used by the system controller to advise
a user whether the detected drug matches the expected drug
characteristics according to the data held in the syringe. If
sleeve 25 included calibration or empty/full capacitance or
inductive coupling data then this could be used in the system
controller's calculations to determine the amount of fluid within
the reservoir, and a visual and/or audible output of this parameter
could also be provided to the user.
Second Embodiment
[0134] FIGS. 8 to 14 show a second embodiment of the invention,
which includes among other things comprises an optical reader for
determining the quantity of liquid drug in the syringe and a
flat-sided optical window. This embodiment also includes optionally
comprises a corresponding docking station. The second embodiment is
utilised in a similar manner as the first embodiment. That is, it
can be used to implement qualitative and quantitative analysis of
the contents of the syringe. Again, while this embodiment is
described with reference to a syringe, it should be noted that the
invention is equally applicable to other types of liquid delivery
devices noted for the first embodiment.
[0135] Referring to FIG. 8, the basic syringe 1 is similar to that
shown in FIG. 1 and has the same reservoir portion 2 and liquid
dispensing means or plunger 3. The general description of the
syringe for the first embodiment applies for the second embodiment
and the details will not be repeated here. The optical window
section 80 in the second embodiment is formed as a flat four-sided
transparent portion that attaches to or is integrally formed with
the bottom portion of the syringe. The syringe 1 also comprises a
detachable optical reader 80. The optical reader detects markings
82 on the syringe plunger 3 to determine the extent to which the
plunger has been moved, and from this, the quantity of liquid in
the syringe can be inferred. The reader 120 comprises electronics
(to be described later) for reading and processing the optical
information, and a transceiver for communication of the information
to a remote system. The optical reader 120 is also fashioned to
function as a handle to assist use of the device. Referring briefly
to FIGS. 10a to 10c, the syringe is adapted to sit in a holder 100.
This enables spectral analysis of the contents of the syringe.
[0136] The syringe, 1 and in particular the window 80 will be
described in more detail with reference to FIG. 8 and the schematic
cross-section depiction in FIG. 9a. The flat-sided window comprises
four planar transparent panels 80a-80d (of which three are visible
in FIG. 8) that allow for transmission of radiation. The panels are
arranged at right angles to form a receptacle 91 with a square or
rectangular cross-section. The panels may be square or rectangular
and need not be all the same size. The receptacle 91 can hold a
portion of the liquid in the reservoir and is in fluid
communication with it. This enables the device to be used in
transmission and reflectance spectral analysis equipment. The
bottom portion of the window 80 is substantially closed off (not
visible), except for an outlet 94 through which drug expelled from
the syringe 1 can escape. The window outlet might also comprise, or
be adapted for connection to, a needle 90 or IV administration set
(not shown) or other delivery device. The window 80 is formed from
a suitable optical material, the panels 80a-80d being joined by a
suitable method or moulded as one piece.
[0137] The window 80 of FIGS. 8 and 9a is formed as part of a
separate component 92 that is attachable to an existing syringe 1
and more particularly the reservoir 2 of the syringe. The component
92 includes a square attachment portion 93 extending from the
planar window 80, which has a larger cross-sectional area. The
attachment portion 93 is dimensioned to enable the component 92 to
sit over the outlet fitting 11 and attach to the bottom of the
standard syringe 1 reservoir. The attachment portion 93 will
include an engagement means (not visible) that enables the
component 92 to connect to the outlet 11 or other part of the
syringe bottom 1 to effect a connection thereto. In a possible
variation, the attachment portion 92 could be integrally attached
to or formed with the syringe 1 reservoir via a suitable moulding
or other process. The attachment portion 92 is substantially hollow
to allow liquid expelled from the syringe reservoir 2 to pass
through to the outlet 94 in the window bottom and escape the
syringe 1 via needle 90. Liquid can also be retained in the
receptacle 91 of the window 80 for analysis purposes. The component
92 could be produced and supplied independently from the syringe 1,
and would be adapted for use with standard issue syringes.
Preferably there are four planar panels although less are possible.
In an alternative embodiment shown in FIG. 9b, there is no
attachment portion, but rather the flat-sided window 80 is
integrally formed with the syringe 1 bottom during the
manufacturing process of the syringe. A leur 11 is formed at the
bottom of the window. The window could be manufactured separately
and then moulded to a syringe, or moulded as part of the syringe as
a single process, such as an injection moulding process.
Preferably, the syringe and window could be formed from
polypropylene. The advantage of using the same plastic for the
syringe body and the window is that the syringe./window can be
formed in a single piece as a single process. This is in contrast
to where the window might be formed as a separate component of a
different plastics, and the welded or otherwise integrated with the
syringe body. In this case, the window 80 forms an integral part of
the reservoir. The window 80 is effectively formed as part of the
syringe 1, with two side panel windows "cut-off" to provide
parallel window sections. In another alternative shown in FIG. 9c
four flat panels 80a-80d are formed as part of the bottom of the
syringe reservoir 2.
[0138] The flat-sided optical window 80 is formed of a suitable
material with close manufacturing tolerances for both its physical
and optical properties. Suitable materials from which the optical
window may be made comprise cast or extruded Acrylic plastics,
Polycarbonate plastics, Butyrate plastics, polypropylene and Clear
PVC. The planar nature of each side provides a known path for
incident radiation, and the thickness of each transparent side is
known to ensure it is suitable for the wavelength radiation being
used.
[0139] In terms of the controlled physical properties, the
thickness of the window panels 80a-80d should be within
predetermined ranges. Preferably, they are 1 mm thick. The material
chosen for the optical window should have low distortion
properties, no or minimal fading, shrinking lines or optical
distortion. Flatness is also important as is the ability to
reproduce wall thickness and, for use in a transmission mode
spectroscopic system, wall separation. The wall thickness may range
from about 0.6 mm to about 1.2 mm and preferably 1 mm thick. The
wall separation (the distance between the wall surface through
which light enters and the surface where affected light enters the
sensor opposite) may range from about 8 mm to about 12 mm, and
preferably around 10 mm. Preferably, the predetermined optical
characteristics include the optical density and clarity of the
optical window section. Importantly, the material chosen for the
optical window should be substantially transparent with low
absorbance, preferably a low absorbance particularly in the near
infra-red range. Polycarbonate plastics may therefore be especially
suitable.
[0140] Referring now to FIGS. 10a to 10c, the syringe 1 with an
attached or integrally formed flat-sided window 80 is adapted for
use with a holder or docking station 100. FIG. 10a shows a
perspective view of a syringe 1 partially installed in the holder
100, and FIG. 10b shows in more detail a syringe 1 being installed.
FIG. 10c shows a plan elevation view of a syringe 1 installed in
the holder 100. The holder 100 retains the syringe 1 in place, and
enables radiation to be directed towards the window 80 to enable
spectral analysis of the syringe 1 contents. The holder comprises a
base 101, with a docking stand 102 extending from the base. The
stand is preferably angled to assist with convenient operation. The
stand 102 comprises a support portion 103 for supporting a syringe
1 installed in the stand. The stand also includes an internal
recess 110 (shown in FIG. 11a). The recess is shaped and
dimensioned to receive the flat-sided window 80 attached to the
syringe. Once installed, the window 80 is retained in the recess
110 and the reservoir 2 of the syringe 1 rests against the support
103. The stand further comprises a second internal recess (not
visible) extending from the first recess 110 towards the base 101
adapted to receive a needle attached to the window 80. The docking
stand 102 might also include a window, aperture or other viewing
portion to enable the user to view the docking process. This window
shows a spring loaded reference tile 104. When the syringe is not
in the docking station, the spring pushes a reference tile into the
light path. When the syringe is in the holder, the reference tile
is displaced and the sample under investigation can be optically
analysed.
[0141] The stand 102 has two optical terminations 105a, 105b
positioned on the outer walls of the stand either side of the
internal recess 110. Each termination 105a, 105b is adapted for
coupling to a fibre optic cable or other optical transmission means
by way of a screw mechanism or similar. Each termination also has
an internal aperture 113 or other optical transmission means that
extends through the termination and through the exterior wall of
the stand adjacent the recess to provide an optical path 111 (e.g.
see FIG. 11a) to the recess 110. By coupling a fibre optic cable or
the like to a termination 105a, 105b, radiation can be transmitted
into the recess 110. When a flat-sided window 80 is in the recess
110, this radiation 111 will be transferred through the window 80
into the liquid inside. Likewise, radiation 112 coming from the
recess can be received at an external sensor coupled to the
termination 105a.
[0142] FIG. 11a is a top cross-sectional view showing the
flat-sided window 80 of the syringe 1 positioned snugly in the
recess 110 of the holder 100. In particular, the tight fit and
square shape prevents rotational movement of the syringe. As noted
earlier, the window 80 could be formed with a rectangular shaped
cross-section. The known properties of the flat-sided window, along
with its secure retention to reduce the risk of rotation provides
more certainty in the optical parameters. As rotation of the window
in the holder is prevented, or at least reduced, the incident
radiation path 111 will be known along with the known properties of
the window 80, which provides for a more accurate determination of
the contents of the liquid drug. Preferably, the incident path 111
of radiation incident on the window panel 80c from the termination
105b will be normal to the face of the window panel 80c. Similarly,
radiation 112 transmitted through or reflected from liquid in the
window 80 will travel normally through the window panel 80bc and to
the receiving termination 105a.
[0143] Referring to FIG. 11b, in a further embodiment, the
flat-sided optical window 80 might include rails, engagement
portions or other protrusions 115a-115d, which engage with a
corresponding channel 116a-116d or the like in the holder 100. This
further assists in retaining the installed syringe 1 in a fixed
rotational position. It also assists with insertion and location of
the window 80 into the recess in the correct orientation.
[0144] Referring to FIG. 9b, the plunger, which is provided with a
rubber or elastomeric head 5, also preferably comprises an
extension portion 95. The extension portion is profiled to slide
with a tight fit into the window portion 80 when the plunger 6 is
pushed downwards as shown in FIG. 9b. This ensures any liquid that
resides in the window portion 80 receptacle 91 is expelled through
the outlet 94 upon actuating the syringe. While the extension
portion 95 is not essential, it prevents wastage of liquid which
might remain in the window portion 80 by use of a standard plunger
head. FIG. 9c shows the plunger such that the extension is
retracted from the receptacle 91.
[0145] The syringe 1 is also adapted to be used with a detachable
optical reader 120 for determining the quantity of liquid drug
within the reservoir 2, as shown in FIGS. 12a to 13 FIG. 12a shows
the reader 120 detached from the syringe 1, while FIG. 12b shows
the reader 120 attached. The optical reader comprises a body
portion 121 for retaining the required electronics for optical
reading and clip means 122a-124b for attaching the optical reader
120 to the reservoir. The middle clips 123a, 123b are resilient and
engage around the circumference of the reservoir below the flange
7. The top clips 124a, 124b sit above the flange 7 and resiliently
clip around the cross arms of the plunger 6 (visible in FIG. 13)
Similarly, the bottom clips 122a, 122b resiliently engage with the
reservoir 2 further down its length. The reader 120 also comprises
preferably two optical receivers 140 (one of which is visible in
FIG. 13, the other is directly underneath and not visible), which
might be photodiodes or similar. The plunger 63 is formed as a
cross-shaped extrusion as shown in FIG. 13. The flange 6 is removed
from FIG. 13 for clarity.
[0146] The plunger 3 comprises optically readable markings 82 on
the flat face of at least one arm of the cross 131d (see e.g. FIG.
8). The optically readable markings 82 are preferably a plurality
of markings positioned at least partially along the longitudinal
length of the arm 131d. The known spacing or arrangement of the
markings allow the position and/or direction of the plunger 3 to be
determined. Preferably the markings are linearly arrange black bars
82. Alternatively, other types of optically readable markings can
be used. The photodetectors e.g. 140 are arranged on the reader so
they can detect the optical markings 82 on the plunger 3.
[0147] The markings 82 can be used to determine linear movement of
the plunger. As the plunger 3 is moved downwards within the
reservoir 2, the optical detectors 140 detect the bars on the
plunger. The optical detectors detect each bar and feed this
information into the electronics, which can count the number of
bars to determine the position of the plunger 3 and thereby infer
how far the plunger 3 has moved within the reservoir 2. The
processor of the electronics determines position data from this.
This in turn indicates the quantity of liquid drug remaining within
the reservoir 2. That is, the longitudinal positional movement of
the plunger 3 within the reservoir 2 defines a cavity in the
reservoir for liquid. Therefore assuming there is no air space in
that cavity, once the position of the plunger in its longitudinal
position within the reservoir is known, the size of the cavity can
be determined and therefore the amount of liquid therein. Therefore
by counting the number of black bars that have passed the
detectors, the longitudinal movement in the reservoir can be known.
This works in both directions, therefore if the plunger is
retracted back to increase the cavity size, by counting the number
of bars the amount of retraction is known and therefore the cavity
size and the amount of liquid.
[0148] To enable determining the size of the cavity based on
movement of the plunger 3 in both directions, two optical detectors
are provided as shown in FIG. 15a, 15b. The use of two optical
detectors enables quadrature encoding to allow the absolute
position and direction of the plunger 3 movement to be determined.
The use of quadrature encoding will be described in relation to
FIGS. 15a, and 15b. A possible embodiment for the circuits of the
quadrature detector are shown in FIG. 17 These Figures shown two
spaced apart photodetectors 140a, 140b which individually can
detect black bars on the plunger 3 and feed this information to the
electronics, including the processor. From this the number of bars
that have passed a detector can be counted and movement
longitudinally of the plunger determined as described previously.
Together the two photodetectors also provide information on which
direction the plunger is moving.
[0149] As shown in FIG. 15a the first photodetector 140a is
situated in a position such that it detects bar 160. The second
photodetector 140b is in a position where it does not detect a bar.
It should be noted that the photodetectors have to be spaced apart
a different distance in the spacing between the bars such that the
photodetectors do not detect bars or at least the edges of bars
simultaneously. Next, as shown in FIG. 15b the plunger 3 has been
moved such that bar 160 is now detected by the second photodetector
140b. At this point the first photodetector 140a does not detect
any bar. Because the first photodetector 140a detected a bar and
then second photodetector 140b detected a bar subsequently, (prior
to photodetector a detecting any other bar) the electronics can
infer that the direction of movement of the plunger is downwards as
shown by the arrow 161. It can therefore know that as each detector
detects a bar this means the volume of the cavity is decreasing by
an amount proportional to the distance between the bars. Each time
another bar is detected in this manner again the electronics can
infer that the size of the cavity and the amount of liquid has
again decreased by amount proportional to the distance between the
bars. Those skilled in the art will know that the cavity size will
be related to the diameter of the syringe and the distance between
the bottom of the plunger 5 and the bottom of the syringe reservoir
2. The distance between the bottom of the plunger and the bottom of
the syringe reservoir will be related to the movement of the
syringe in the reservoir and therefore the position of the bars as
they move past the detectors.
[0150] Similarly, quadrature encoding can determine when the
syringe is moving in the opposite direction. When the syringe has
moved upwards, the photodetectors 140a, 140b can detect the
direction of movement and the number of bars they transverse
indicates the increase in the size of the cavity between the bottom
of the plunger and the bottom of the syringe reservoir. In turn
this indicates the amount of liquid in the cavity if liquid is
being drawn into the syringe through the needle.
[0151] The use of quantity analysis in this manner enables the
quantity of liquid in the syringe to be determined when the syringe
is actually being actuated. It is not necessary for the syringe to
be installed in a holder. Therefore the syringe can provide
continuous and real-time measurements of the quantity of liquid in
the syringe.
[0152] The optical reader 120 can either be hard wired or
preferably wirelessly connected to the spectral analyser to relay
the quantity information. The optical reader 120 can also be
attached and detached from the reservoir 2 as required. Other forms
of optical markings and processing could be used to determine the
extent that the plunger 3 has moved.
[0153] The optical reader 120 is moulded to also act as a holder to
enable a person to use the device, for example as shown in FIG. 8.
The reader 120 also comprises clip means 130a-130d extending from
the upper resilient clips 124a, 124b as shown in FIG. 13. The clip
means 130a-130d extend from the upper resilient arms 124a, 124b and
engage with one or more of the flat arms 131a-131d of the extruded
plunger 3. By doing so the clip means restricts rotational movement
of the plunger 3, and allows the plunger to solely move in a linear
manner. This ensures that the squared profiled plunger 95 extension
portion will be received properly into the internal portion of the
window 80 when the plunger 3 is forced downwards. Any rotation of
the plunger 3 might prevent the plunger extension portion 95
extending into the window 80 and therefore prevent all liquid being
expelled from the syringe 1. Alternatively, a flip disc that is
hingeably connected to the syringe and that has openings
corresponding to the cross arms of the plunger could be used. To
prevent rotation of the plunger, the flip disc could be flipped
about its hinge and snap locked onto the top of the plunger. This
will prevent rotation but still allow longitudinal movement of the
plunger.
[0154] FIG. 14 shows a block diagram of the electronics in the
optical reader 120. The photodetectors 140a, 140b, which are
positioned on the clips 124a, 124b to detect the plunger markings
42, are connected to a processor 141. This could be a
microprocessor, microcontroller or similar. The processor 141
receives information on the markings from the detectors 140, and
from this determines the position of the plunger 3 within the
reservoir 2 and the direction of movement. From this, the liquid
quantity in the reservoir 2 can be inferred by the processor 141,
or other system. The processor 141 is connected to a wireless
transceiver 142 to transmit the quantitative analysis information
(or information from which this analysis can be performed) to a
computer system 151 via a transceiver 143, where the information
can be used as required. The wireless transceiver 141 can any
suitable type, such as an optical or radio (e.g. RF) transceiver.
The electronics also comprises a battery 149 for powering the
electronics, and an inductive coupler (150a in FIG. 14, 180 in FIG.
12b) for coupling the battery to an external inductive charging
means (150b in FIG. 14, 181 in FIG. 12b). The secondary circuit of
the inductive charger 180 is shown in FIG. 16. As shown in FIG.
12b, the optical reader has an inductive charger coil 180 extending
therefrom. When the syringe engages in the docking station as shown
in FIG. 10b, the charger coil 180 extending from the reader will
engage, abut or otherwise couple to the inductive charger coil 181
on the docking station to allow for inductive coupling and charging
of the battery.
[0155] FIG. 14 shows in schematic form the overall system and
indicates its overall functionality. The system is adapted for use
with the syringe as described previously. The optical reader 120
with the photodetectors 140a, 140b is adapted for connection to the
syringe. The optical quantitative analysis information it reads
from the syringe 1 is processed and then the information sent to
the computer system 151 via the wireless link transceiver 142. The
processor 141 can process the optical information to infer
quantitative analysis, or otherwise provide raw information which
is then processed by the computer system (preferably located
separated from the holder 100 and syringe 1). The system also
includes the holder 100 for receiving the syringe 1. The holder
includes a light source 146 for directing incident radiation onto
the drug in the window of the installed syringe, and a sensor 145
(two alternatives shown) for sensing the received radiation that
has been affected by the drug in the window. Alternatively, the
light source and sensor are remotely positioned, and the light
transferred to the holder using a suitable means. The sensed
information is then transmitted, preferably wirelessly, via the
transceiver 142 to the spectrum analyser 147 of the computer system
151. The spectrum analyser 147 determines the drug type from the
spectral analysis information received from the sensor 145. A
system controller 144 is connected to the analyser 147 and an audio
device such as a speaker 148a and a display unit 148b. The system
controller 147 receives spectrum data from the spectroscopic
analyser and may compare this to stored "fingerprint" data from
known liquid drugs to determine a best match drug. The display unit
148b and/or speaker 148a may then provide visual and/or audible
information to a user of the drug which most closely matches the
contents of the reservoir. Alternatively, the display device 148a
could output a graphical display of the drugs liquid's photometric
spectrum for review by the user. The system controller 144 also
receives the quantity information and advises the user accordingly,
and provides any alerts or warnings regarding the quantity of drug
in the reservoir, or the quantity of drug administered to a
patient. It will be appreciated by those skilled in the art that
the quantitative and qualitative analysis information received from
the holder 100 and optical reader 120 could be used in numerous
ways to provide various checks and information to the user.
[0156] A method of use of the invention will now be described with
reference to FIGS. 8 and 10a. Referring to FIG. 10a, the medic will
first fill the reservoir 2 of the syringe 1 with the desired drug
or other liquid and then position the plunger 3 so that it contains
the correct quantity of the drug in accordance with the human
readable markings 153 on the side of the syringe 1. The medic
ensures that a portion of the drug sits within the window 80 of the
syringe. The syringe is then docked into the docking station 100 by
inserting the window 80 into the recess 110 and resting the
cylinder of the syringe 1 on the support 103. If not done already,
the terminations 105a, 105b of the holder 100 will be connected to
an incident radiation source and an optical sensor respectively
(shown schematically in FIG. 14). The optical sensor 145 may be
hard wired directly to the spectrum analyser 147 and computer
system or alternatively the information can be transmitted
wirelessly to such a system. Alternatively, the affected radiation
leaving the sample under observation might be optically transmitted
to the spectrum analyser 147 either through fibre optic cable or
wirelessly.
[0157] When the syringe 1 is installed, the drug within the window
80 will sit in the recess 110 within the optical path of the source
radiation 146. The analyser system 147 can then be activated and a
spectral reading taken from the incident radiation on the drug
within the window 80. This can be processed in the usual way and
the medic advised as necessary. Simultaneously, or at another
suitable time the optical reader 120 is activated to read the
markings 82 on the plunger of the syringe in order to determine
quantitatively the amount of liquid within the syringe 1. This can
be done in real-time such that a continuous or periodic quantity
reading can be made as the plunger is moved. This is also
transmitted wirelessly to the computer system 151a which uses the
information and provides any warnings or advice to the medic as
required. When the qualitative and quantitative analysis has been
made, the medic can then remove the syringe 1 from the docking
station 100. Note, the syringe does not have to be in the holder to
take a quantity reading. The medic can then administer the drug to
a patient by holding the device 1 as shown in FIG. 8 and pressing
on the plunger 3 to expel the liquid from the syringe 1.
[0158] FIG. 8 shows the syringe in use. The user can attach the
optical reader 120 to the reservoir 2 and then hold the syringe 1
by placing their forefinger under the curved surface of the bottom
of the optical reader 120 and placing their thumb on the top 6 of
the plunger 3. They can then inject the contents from the syringe 1
by pressing on the plunger 3 with their thumb in the usual manner.
The plunger 3 will move downwards into the reservoir 2 and in doing
so the optical markings 82 on the plunger 3 will pass the optical
receptors 140 in the reader 120. As the markings 82 pass the
optical receptors 140a, 140b the markings 82 are detected and the
information passed to the processor 141, which determines the
direction and extent of movement of the plunger 3 within the
reservoir 2. This information can then be used to determine the
quantity of liquid drug within the syringe as mentioned previously.
This information can be used in any desired manner, such as
providing a warning when too little or too much of a drug has been
dispensed or providing any other useful information.
[0159] As noted, the syringe is adapted to be used in conjunction
with a qualitative analysis device such as the spectroscopic
analyser 147 to determine the composition of material within the
reservoir. Accordingly, optical window 80 is manufactured within
known optical and physical tolerances so that it has a known affect
on radiation passing therethrough. The optical window section 80
will therefore cause a known reduction in light intensity at known
frequencies and this effect can be factored in to calculations
carried out by the spectroscopic analyser 147. The spectroscopic
analyser may then determine an accurate spectroscopic "fingerprint"
of the liquid within reservoir for comparison with spectroscopic
data of known drugs. In this way, as a drug is being administered
to a patient by the syringe or just prior to delivery of a drug
using the syringe, it is possible to check that the drug being
delivered is that which is intended to thereby avoid or reduce the
risk of an adverse drug event.
[0160] Reflectance mode spectroscopic analysis may be carried out
on the syringe by causing light, for example in the near-infrared
(NIR) spectrum, to be incident on the optical window section 80.
The incident light will be transmitted through the optical window
section while being effected by the optical window section in a
known way, interact with the contents within receptacle and then
some of the incident light will be reflected back through the
optical window section to a detector having been affected in a
known way as it travels back through the optical window
section.
[0161] Any suitable method of spectroscopic analysis could be used,
for example those mentioned in relation to the first
embodiment.
[0162] Alternatively, transmission mode spectroscopy could be
employed to determine the composition of the contents of the
reservoir.
[0163] While this is preferred a preferred embodiment, alternatives
are possible. It will be appreciated that the window could comprise
more than four panels (e.g., have hexagonal, octagonal profiles or
the like), or the window could comprise less that four panels, such
as three. One possibility is that the window could have one or two
planar panels, with the remainder being formed as a circular shape,
or some other non-planar shape. In such an embodiment, the recess
in the stand would be shaped accordingly to receive the window, and
the plunger extension as shaped accordingly.
[0164] The present invention provides a low cost and disposable
liquid delivery device (such as a syringe) and associated
spectroscopic system which enables a user to determine, at a
patient's bedside whether a drug which is about to be injected is
what is intended. As the syringe is disposable, it will only ever
hold a single type of liquid and will not therefore suffer from
contamination which could otherwise skew spectroscopic analysis
results. The syringe is also advantageously portable and could even
be utilised (to dispense liquids) whilst located within housing
12.
* * * * *