Note: Descriptions are shown in the official language in which they were submitted.
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REAL-TIME INVENTORY RE-SUPPLY SYSTEM
[0001]
BACKGROUND
[0002] The invention relates generally to the field of wireless
identification of medical
articles in a healthcare setting, and more particularly, to a system and
method for managing
the inventory of medical article containers.
[0003] There are a number of ways of identifying and tracking articles
including visually,
optically (bar coding, for example), magnetically, RFID, weighing, and others.
Where an
automatic system for tracking is desired, RFID is a candidate since
identification data may be
obtained wirelessly. RFID tags have decreased in cost, which has made them
even more
attractive for such an application.
[0004] Radio-frequency identification ("RFID") is the use of
electromagnetic energy
("EM energy") to stimulate a responsive device (known as an RFID "tag" or
transponder) to
identify itself and in some cases, provide additionally stored data. RFID tags
typically
include a semiconductor device having a memory, circuitry, and one or more
conductive
traces that form an antenna. Typically, RFID tags act as transponders,
providing information
stored in the semiconductor device memory in response to an RF interrogation
signal
received from a reader, also referred to as an interrogator. Some RFID tags
include security
measures, such as passwords and/or encryption. Many RFID tags also permit
information to
be written or stored in the semiconductor memory via an RF signal.
[0005] RFID tags may be incorporated into or attached to articles to be
tracked. In some
cases, the tag may be attached to the outside of an article with adhesive,
tape, or other means
and in other cases, the tag may be inserted within the article, such as being
included in the
packaging, located within the container of the article, or sewn into a
garment. The RFID tags
are manufactured with a unique identification number which is typically a
simple serial
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number of a few bytes with a check digit attached. This identification number
is incorporated
into the tag during manufacture. The user cannot alter this
serial/identification number and
manufacturers guarantee that each serial number is used only once. This
configuration
represents the low cost end of the technology in that the RFID tag is read-
only and it
responds to an interrogation signal only with its identification number.
Typically, the tag
continuously responds with its identification number. Data transmission to the
tag is not
possible. These tags are very low cost and are produced in enormous
quantities.
[0006] Such read-only RFID tags typically are permanently attached to an
article to be
tracked and, once attached, the serial number of the tag is associated with
its host article in a
computer database. For example, a particular type of medicine may be contained
in hundreds
or thousands of small vials. Upon manufacture, or receipt of the vials at a
health care
institution, an RFID tag is attached to each vial. Each vial with its
permanently attached
RFID tag will be checked into the database of the health care institution upon
receipt. The
RFID identification number may be associated in the database with the type of
medicine, size
of the dose in the vial, and perhaps other information such as the expiration
date of the
medicine. Thereafter, when the RFID tag of a vial is interrogated and its
identification
number read, the database of the health care institution can match that
identification number
with its stored data about the vial. The contents of the vial can then be
determined as well as
any other characteristics that have been stored in the database. This system
requires that the
institution maintain a comprehensive database regarding the articles in
inventory rather than
incorporating such data into an RFID tag.
[0007] An object of the tag is to associate it with an article throughout
the article's life in
a particular facility, such as a manufacturing facility, a transport vehicle,
a health care
facility, a storage area, or other, so that the article may be located,
identified, and tracked, as
it is moved. For example, knowing where certain medical articles reside at all
times in a
health care facility can greatly facilitate locating needed medical supplies
when emergencies
arise. Similarly, tracking the articles through the facility can assist in
generating more
efficient dispensing and inventory control systems as well as improving work
flow in a
facility. Additionally, expiration dates can be monitored and those articles
that are older and
about to expire can be moved to the front of the line for immediate
dispensing. This results
in better inventory control and lowered costs.
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[0008] Other RFID tags are writable and information about the article to
which the RFID
tag is attached can be programmed into the individual tag. While this can
provide a distinct
advantage when a facility's computer servers are unavailable, such tags cost
more, depending
on the size of the memory in the tag. Programming each one of the tags with
information
contained in the article to which they are attached involves further expense.
[0009] RFID tags may be applied to containers or articles to be tracked by
the
manufacturer, the receiving party, or others. In some cases where a
manufacturer applies the
tags to the product, the manufacturer will also supply a respective database
file that links the
identification number of each of the tags to the contents of each respective
article. That
manufacturer supplied database can be distributed to the customer in the form
of a file that
may easily be imported into the customer's overall database thereby saving the
customer from
the expense of creating the database.
[0010] Many RFID tags used today are passive in that they do not have a
battery or other
autonomous power supply and instead, must rely on the interrogating energy
provided by an
RFID reader to provide power to activate the tag. Passive RFID tags require an
electromagnetic field of energy of a certain frequency range and certain
minimum intensity in
order to achieve activation of the tag and transmission of its stored data.
Another choice is an
active RFID tag; however, such tags require an accompanying battery to provide
power to
activate the tag, thus increasing the expense of the tag and making them
undesirable for use
in a large number of applications.
[0011] Depending on the requirements of the RFID tag application, such as
the physical
size of the articles to be identified, their location, and the ability to
reach them easily, tags
may need to be read from a short distance or a long distance by an RFID
reader. Such
distances may vary from a few centimeters to ten or more meters. Additionally,
in the U.S.
and in other countries, the frequency range within which such tags are
permitted to operate is
limited. As an example, lower frequency bands, such as 125 KHz and 13.56 MHz,
may be
used for RFID tags in some applications. At this frequency range, the
electromagnetic energy
is less affected by liquids and other dielectric materials, but suffers from
the limitation of a
short interrogating distance. At higher frequency bands where RFID use is
permitted, such as
915 MHz and 2.4 GHz, the RFID tags can be interrogated at longer distances,
but they de-
tune more rapidly as the material to which the tag is attached varies. It has
also been found
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that at these higher frequencies, closely spaced RFID tags will de-tune each
other as the
spacing between tags is decreased.
[0012] There are a number of common situations where the RFID tags may be
located
inside enclosures. Some of these enclosures may have entirely or partially
metal or
metallized surfaces. Examples of enclosures include metal enclosures (e.g.,
shipping
containers), partial metal enclosures (e.g., vehicles such as airplanes,
buses, trains, and ships
that have a housing made from a combination of metal and other materials), and
non-metal
enclosures (e.g., warehouses and buildings made of wood). Examples of objects
with RFID
tags that may be located in these enclosures include loose articles, packaged
articles, parcels
inside warehouses, inventory articles inside buildings, various goods inside
retail stores, and
various portable articles (e.g., passenger identification cards and tickets,
baggage, cargo,
individual life-saving equipment such as life jackets and masks) inside
vehicles, etc.
[0013] The read range (i.e., the range of the interrogation and/or response
signals) of
RFID tags is limited. For example, some types of passive RFID tags have a
maximum range
of about twelve meters, which may be attained only in ideal free space
conditions with
favorable antenna orientation. In a real situation, the observed tag range is
often six meters or
less. Therefore, some of the enclosures described above may have dimensions
that far exceed
the read range of an individual RFID tag. Unless the RFID reader can be placed
in close
proximity to a target RFID tag in such an enclosure, the tag will not be
activated and read.
Additionally, metal surfaces of the enclosures present a serious obstacle for
the RF signals
that need to be exchanged between RFID readers and RFID tags, making RFID tags
located
behind those metal surfaces difficult or impossible to detect.
[0014] In addition to the above, the detection range of the RFID systems is
typically
limited by signal strength to short ranges, frequently less than about thirty
centimeters for
13.56 MHz systems. Therefore, portable reader units may need to be moved past
a group of
tagged items in order to detect all the tagged items, particularly where the
tagged items are
stored in a space significantly greater than the detection range of a
stationary or fixed single
reader antenna. Alternately, a large reader antenna with sufficient power and
range to detect
a larger number of tagged items may be used. However, such an antenna may be
unwieldy
and may increase the range of the radiated power beyond allowable limits.
Furthermore,
these reader antennae are often located in stores or other locations where
space is at a
premium and it is expensive and inconvenient to use such large reader
antennae. In another
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possible solution, multiple small antennae may be used but such a
configuration may be
awkward to set up when space is at a premium and when wiring is preferred or
required to be
hidden.
[0015] In the case of medical supplies and devices, it is desirable to
develop accurate
tracking, inventory control systems, and dispensing systems so that RFID
tagged devices and
articles may be located quickly should the need arise, and may be identified
for other
purposes, such as expiration dates. In the case of medical supply or
dispensing cabinets used
in a health care facility, a large number of medical devices and articles are
located closely
together, such as in a plurality of drawers. Cabinets such as these are
typically made of
metal, which can make the use of an external RFID system for identification of
the stored
articles difficult. In some cases, such cabinets are locked due to the
presence of narcotics or
other medical articles or apparatus within them that are subject to a high
theft rate. Thus,
manual identification of the cabinet contents is difficult due to the need to
control access.
[0016] Providing an internal RFID system in such a cabinet can pose
challenges. Where
internal articles can have random placement within the cabinet, the RFID
system must be
such that there are no "dead zones" that the RFID system is unable to reach.
In general, dead
zones are areas in which the level of coupling between an RFID reader antenna
and an RFID
tag is not adequate for the system to perform a successful read of the tag.
The existence of
such dead zones may be caused by orientations in which the tag and the reader
antennae are
in orthogonal planes. Thus, articles placed in dead zones may not be detected
thereby
resulting in inaccurate tracking of tagged articles.
[0017] Often in the medical field, there is a need to read a large number
of tags attached
to articles in such an enclosure, and as mentioned above, such enclosures have
limited access
due to security reasons. The physical dimension of the enclosure may need to
vary to
accommodate a large number of articles or articles of different sizes and
shapes. In order to
obtain an accurate identification and count of such closely-located medical
articles or
devices, a robust electromagnetic energy field must be provided at the
appropriate frequency
within the enclosure to surround all such stored articles and devices to be
sure that their tags
are all are activated and read. Such medical devices may have the RFID tags
attached to the
outside of their containers and may be stored in various orientations with the
RFID tag (and
associated antenna) pointed upwards, sideways, downward, or at some other
angle in a
random pattern.
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[0018] Generating such a robust EM energy field is not an easy task. Where
the
enclosure has a size that is resonant at the frequency of operation, it can be
easier to generate
a robust EM field since a resonant standing wave may be generated within the
enclosure.
However, in the RFID field the usable frequencies of operation are strictly
controlled and are
limited. It has been found that enclosures are desired for the storage of
certain articles that do
not have a resonant frequency that matches one of the allowed RFID
frequencies. Thus, a
robust EM field must be established in another way.
[0019] Additionally, where EM energy is introduced to such an enclosure for
reading the
RFID tags within, efficient energy transfer is of importance. Under static
conditions, the
input or injection of EM energy into an enclosure can be maximized with a
simple impedance
matching circuit positioned between the conductor delivering the energy and
the enclosure.
As is well known to those of skill in the art, such impedance matching
circuits or devices
maximize the power transfer to the enclosure while minimizing the reflections
of power from
the enclosure. Where the enclosure impedance changes due to the introduction
or removal of
articles to or from the enclosure, a static impedance matching circuit may not
provide
optimum energy transfer into the enclosure. If the energy transfer and
resulting RF field
intensity within the enclosure were to fall below a threshold level, some or
many of the tags
on articles within the enclosure would not be activated to identify
themselves, leaving an
ineffective inventory system.
[0020] It is a goal of many health care facilities to keep the use of EM
energy to a
minimum, or at least contained. The use of high-power readers to locate and
extract data
from RFID tags is generally undesirable in health care facilities, although it
may be
acceptable in warehouses that are sparsely populated with workers, or in
aircraft cargo holds.
Radiating a broad beam of EM energy at a large area, where that EM energy may
stray into
adjacent, more sensitive areas, is undesirable. Efficiency in operating a
reader to obtain the
needed identification information from tags is an objective. In many cases
where RFID tags
are read, hand-held readers are used. Such readers transmit a relatively wide
beam of energy
to reach all RFID tags in a particular location. While the end result of
activating each tag and
reading it may be accomplished, the transmission of the energy is not
controlled except by the
aim of the user. Additionally, this is a manual system that will require the
services of one or
more individuals, which can also be undesirable in facilities where staff is
limited.
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[0021] In a healthcare environment, there are many storage systems for key
medical
articles that are used for different purposes. Some are open access storage
systems. In most
of these cases. and especially for emergency storage systems, they must be
restocked upon
use on a priority basis. Examples of such emergency storage systems are "crash
carts."
"anesthesia carts," and others. See FIG. 23 for an example of a crash cart
300. Such carts
usually include wheels 302 so that they are mobile and may have multiple
drawers 304 in
which various medical articles are stored. An external handle 306 is provided
to assist in
handling the cart 300. Access to these carts must be immediate and unhindered,
and
controlled access is not required. Upon usage of any item in the cart, the
cart must be fully
inventoried for resupply. This takes a significant amount of time to
accomplish correctly.
The need to have these carts immediately available for use requires action
from the pharmacy
in a timely manner. Upon resupply, the carts are usually sealed and placed in
strategic
locations within the healthcare facility for immediate access.
[0022] Another type of storage system is commonly known as a tray or code
tray, and
may have other names. The code is typically used to identify the medical
purpose of the tray,
such as a "code blue" tray to resuscitate a person undergoing cardiac arrest.
Such a tray may
be formed of non-metallic material such as composites or plastics. The tray
holds all of the
medications, tools, and equipment that are expected to be required to complete
a medical
procedure or to handle a particular medical event.
[0023] A tray is typically laid out and displayed in an easily recognizable
fashion. Color
may be used also to assist in managing the inventory of the tray. This allows
an assistant to
retrieve the correct medication or instrument without delay. In the event that
a surgeon is
looking for the optimum tool or medication, a quick glance at the surgical
tray will allow the
identification of all available tools at his or her disposal. Labels are often
placed on the tray
also that specify what is in the pockets of the tray.
[0024] An example of such a medical "tray" is shown in FIG. 24. The tray
320 is a single
layer and includes various pharmaceuticals 322 and other medical articles,
such as pre-loaded
syringes 324 (epinephrine syringe, lidocaine syringe, and an atropine
syringe). The entire
tray is sealed with clear plastic wrap 326 and an inventory list 328 is
contained just under the
plastic seal so that it is visible and readable without breaking the seal. The
Required
Inventory list in this case identifies the name of the tray, such as
"Childbirth Tray," lists the
contents of the tray, and includes other information such as the first
expiration date of any of
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the articles contained in the tray. The Required Inventory list may also
contain a plan layout
of the tray showing which articles should be stored where. It may have
multiple pages or
only a single page.
[0025] The tray 320 has been prepared by a pharmacist at the pharmacy
because it has
prescription medications in it (oxytocin for example). The Required Inventory
list may also
include brand names as well as generic names, and National Drug Codes ("NDCs")
or
Universal Product Codes ("UPCs") as part of the inventory. State regulations
typically allow
a hospital or other facility to define the contents of its trays, and
therefore they can be
selected based on particular "community" standards and requirements. State
regulations,
typically require that the hospital have specific procedures to ensure
accuracy of tray
contents. Such procedures include inventory and restocking procedures, as well
as detection
of expired and recalled medical articles. In the example of FIG. 24, the tray
is relatively
small. However for other purposes, a tray can be much larger with many more
medical
articles. Some trays may include additional layers that include additional
items not contained
in the top layer.
[0026] If the seal is broken, regardless of whether any of the contents
were removed, an
inventory will likely be required. Existing processes require that this be
done manually.
Each of the articles in the tray is examined to determine if it is expired or
recalled, and is
compared against the Required Inventory list to determine if it should be in
the tray. The
Required Inventory list is also referenced for checking that all required
articles are in the tray
and that extra articles are not in the tray. Once it has been restocked, the
tray 320 is resealed
326 and may be placed on the floor again for medical use. Such examination and
restocking
can take significant amounts of time and if a pharmacist is required to
perform some of the
inventory process, that pharmacist will be unavailable to perform other
duties. In such a
manual procedure, mistakes can be made. Thus, a need has been identified to
provide a more
efficient and accurate system and method to restock such carts and trays.
[0027] Crash carts and trays must be resupplied periodically to replace
expired or recalled
items, and if a cart or a tray was actually used, to replace consumed
articles. As mentioned,
such processes are typically performed manually at a significant cost in time.
Missing key
medical articles in a tray could be devastating in an emergency situation.
Therefore accuracy
in the resupply is mandatory. Often, trays that have articles that are just
nearing expiration
must be returned to the pharmacy for resupply in advance of expiration due to
the time it
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takes to process the tray. Any recalled articles must also be removed and
substitutions made.
It is also possible that items foreign to the crash cart or tray have been
added while they were
in the field, and these foreign articles must be found and removed.
[0028] Unfortunately, the above procedures tend to suffer from significant
shortcomings.
For instance, manual inspections can result in errors as can resupply.
Creating records of
what was done is also generally time consuming and error prone, all of which
drive up the
cost of creating and resupplying the carts and trays. There has therefore been
recognized a
need for improvement in managing such crash carts and trays.
[0029] Furthermore, under the current system, the pharmacy is unable to
create
individualized carts for patients. For example, certain patients may be
provided a patient-
specific cocktail of drugs (this may be a mixed vial or a combination of
drugs). Because
these are non-standard drugs or drug combinations, a pharmacist has to double
check a drug
list or a prescription list when creating a cocktail drug or filling a
personalized cart with
medical items.
[0030] Hence, those skilled in the art have recognized a need for an
improved real-time
inventory system for managing medical article container systems. Additionally,
a need has
been recognized for performing such article management with a more compact,
self-
contained wireless reader system that reduces the space needed to inventory
crash carts and
trays. A further need has been recognized for confining the energy used for
reading wireless
medical article identification devices to a particular area so that accuracy
of identification is
obtained. The present invention fulfills these needs and others.
SUMMARY OF THE INVENTION
[0031] Briefly and generally there is provided a system and a method to
manage the
inventories of medical article storage containers, including trays and crash
carts. In a first
aspect, there is provided a medical container re-supply system for reading a
data carrier that
is attached to a medical container and a data carrier attached to a medical
article located in
the storage container to manage the inventory of the storage container, the
data carrier being
responsive to electromagnetic energy (EM) of a frequency fl in response to
which the data
carrier provides identification data, the system comprising a metallic
enclosure having an
internal storage area, the metallic enclosure further having electrically
conductive walls that
completely surround the internal storage area and any medical article with
associated data
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carrier placed therein, the enclosure having a natural frequency of resonance
f2 which is
different from a frequency fl and to which a data carrier that is responsive
to frequency fl is
not responsive, a probe disposed at a metallic wall of the metallic enclosure
within the
metallic enclosure, the probe configured to inject electromagnetic energy of a
frequency fl
into the metallic enclosure, wherein the position of the probe in relation to
the metallic walls
of the metallic enclosure is selected so that reflected EM of frequency fl
within the metallic
enclosure is in phase at the probe position to thereby optimize power transfer
at frequency fl
into the enclosure, an active impedance matching circuit coupled to the probe
and configured
to actively more closely match impedance of the probe to impedance of the
metallic
enclosure at frequency f I, a storage container having a data carrier
identifying the container,
the container being located within the internal storage area of the metallic
enclosure and
containing a medical article with an associated data carrier identifying that
medical article,
both data carriers being responsive to EM at frequency fl but not
operationally responsive to
frequency 12, a receiving antenna disposed within the metallic enclosure and
configured to
receive the identification data provided by the data carrier, a predetermined
required
inventory list of medical articles for the storage container, a non-volatile
memory on which is
stored the inventory list of the storage container, a processor programmed to
receive the
identification data of the storage container and the identification data of
the article in the
storage container, locate the storage container inventory list in the memory
through the
identification of the storage container, locate the details of the medical
article in the storage
container in the memory through the identification data of the medical
article, and compare
the details of the medical article against the required inventory list of the
storage container to
manage the inventory of the container.
[0032] In more detailed aspects, the processor is also configured to
determine if the
article in the storage container is expired through locating the details of
the medical article,
including its expiration date, from the memory, comparing that expiration date
to the present
date, and providing a notice of expiration if the two dates match or if the
expiration date of
the medical article preceded the present date. The memory includes a database
in which the
details of recalled items are contained, and the processor further being
programmed to
compare the details of the medical article in the storage container to the
recalled article
database on the memory, and if the comparison shows that the medical article
is recalled, to
provide an indication of such recall status.
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[0033] In a method aspect in accordance with the invention, there is
provided a method of
re-supplying a medical container by reading a data carrier that is attached to
the medical
container and a data carrier attached to a medical article located in the
storage container to
manage the inventory of the storage container, the data carrier having a
specified operation
frequency f1 in response to which the data carrier provides identification
data, the medical
container and medical article being located within an internal storage area of
a metallic
enclosure, the metallic enclosure further having electrically conductive walls
that completely
surround the internal storage area and any medical article with associated
data carrier placed
therein, the metallic enclosure having a natural frequency of resonance f2
which is a
frequency other than the specified operation frequency f1 of the data carrier,
the method
comprising positioning a storage container within the internal storage area of
the enclosure,
the storage container having a data carrier identifying the container, the
container containing
a medical article with an associated data carrier identifying that medical
article, both data
carriers being responsive to EM at frequency fl but not operationally
responsive to frequency
f2, injecting electromagnetic ("EM") energy of a frequency f1 into the
metallic enclosure
from a location within the enclosure, the injecting location being selected in
relation to the
metallic walls so that reflected energy of frequency f1 within the metallic
enclosure is in
phase at the location of injection to thereby optimize power transfer of EM
energy at
frequency f1 into the enclosure, actively matching an impedance associated
with injecting the
EM energy into the metallic enclosure to more closely match an impedance of
the metallic
enclosure at frequency fi receiving identification data provided by a data
carrier located
within the internal storage area of the metallic enclosure by means of an
antenna disposed
within the metallic enclosure, storing a predetermined required inventory list
of the storage
container on a non-volatile memory, receiving the identification data of the
storage container
and the identification data of the article in the storage container by a
processor, locating the
storage container inventory in the memory by the processor through the
identification of the
storage container, locating the details of the medical article in the storage
container by the
processor in the memory through the identification data of the medical
article, and comparing
the details of the medical article against the required inventory list of the
storage container to
manage the inventory of the container.
[0034] In more detailed aspects, the method further comprises determining
by the
processor if the article in the storage container is expired through locating
the details of the
medical article, including its expiration date, from the memory, comparing
that expiration
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date to the present date, and providing a notice of expiration if the two
dates match or if the
expiration date of the medical article preceded the present date. Also
included is the aspect
of comparing the details of the medical article in the storage container to a
recalled article
database on the memory, and if the comparison shows that the medical article
is recalled,
providing an indication of such recall status about the medical article.
[0035] The features and advantages of the invention will be more readily
understood
from the following detailed description that should be read in conjunction
with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a schematic diagram of a drawer that may be positioned
within a medical
dispensing cabinet, showing the storage of a plurality of medical articles
randomly positioned
in the drawer, each of those articles having an integral RFID tag oriented
randomly;
[0037] FIG. 2 is a perspective view of a medication dispensing cabinet
having five
drawers, one of which is similar to the schematic view of FIG. 1, the cabinet
also having an
integral computer for controlling access to the cabinet and performing
inventory tracking by
periodically reading any RFID tags placed on articles stored within the
cabinet, and for
reporting the identified articles to a remote computer;
[0038] FIG. 3 is a block and flow diagram showing an embodiment in which an
RFID
reader transmits activating EM energy into a drawer containing RFID tags with
a single
transmitting antenna, receives the data output from the activated RFID tags
with a single
receiving antenna, a computer controlling the transmission of activating
energy and receiving
the data from the activated RFID tags for processing;
[0039] FIG. 4 is a block and flow diagram similar to FIG. 3 showing an
embodiment in
which an RFID reader transmits activating EM energy into a drawer containing
RFID tags
with two transmitting antennae, receives the data output from the activated
RFID tags with
three receiving antennae, and as in FIG. 3, a computer controlling the
transmission of
activating energy and receiving the data from the activated RFID tags for
processing;
[0040] FIG. 5 shows an enclosure with a single probe and a connector, the
probe being
configured to inject EM energy into the enclosure and excite a TE mode;
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[0041] FIG. 6 shows an enclosure with a single probe and a connector, the
probe being
configured to inject EM energy into the enclosure and excite a TM mode;
[0042] FIG. 7 shows a plot of coupled power in an enclosure as a function
of frequency
for a resonant enclosure where Fll is the natural resonance frequency of the
enclosure;
[0043] FIG. 8 shows a plot of coupled power (ordinate axis) in an enclosure
as a function
of frequency (abscissa axis), where ff is a forced resonance frequency, or
otherwise referred
to as a frequency that is not equal to the resonant frequency of the
enclosure, and fi, is the
natural resonant frequency of the enclosure, showing the establishment of a
robust field of
coupled power in the enclosure at the ff frequency;
[0044] FIG. 9 shows an enclosure with two probes each with a connector for
injecting
EM energy into the enclosure, one probe being a TM probe and the other being a
TE probe;
[0045] FIG. 10 shows a probe, a connector, and an attenuator that is used
to improve the
impedance match between the probe and the enclosure;
[0046] FIG. 11 shows a probe, a connector, and a passive matching circuit
that is used to
improve the impedance match between the probe and enclosure;
[0047] FIG. 12 shows an active matching circuit connected between a probe
located in an
enclosure and a transceiver, the active matching circuit comprising a tunable
capacitor, a
dual-directional coupler, multiple power sensors, and a comparator used to
provide a closed-
loop, variable matching circuit to improve the impedance match between the
probe and the
enclosure;
[0048] FIG. 13 provides a side cross-sectional view of the cabinet of FIG.
2 at the
location of a drawer with the drawer removed for clarity, showing the
placement of two probe
antennae in a "ceiling mount" configuration for establishing a robust EM field
in the drawer
when it is in place in the cabinet in the closed position;
[0049] FIG. 14 is a perspective view of the metallic enclosure showing the
probe
configuration of FIG. 13 again showing the two probe antennae for establishing
a robust EM
field in a drawer to be inserted;
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[0050] FIG. 15 is a cutaway perspective side view of the metallic enclosure
or frame in
which are mounted the dual probe antennae of FIGS. 13 and 14 with the drawer
removed for
clarity;
[0051] FIG. 16 is a frontal perspective view of the view of FIG. 14 with a
cutaway plastic
drawer in place in the metallic enclosure and further showing the dual ceiling
mount probe
antennae protected by an electromagnetically inert protective cover, and
further showing
cooling system components mounted at the back of the cabinet near the drawer's
back, the
drawing also showing a partial view of a drawer slide mechanism for ease in
sliding the
drawer between open and closed positions in the cabinet, the drawer front and
rear panels
having been cutaway in this view;
[0052] FIG. 17 is a frontal perspective view at the opposite angle from
that of FIG. 16
with the plastic drawer completely removed showing the dual ceiling mount
probe antennae
protected by the EM inert protective cover mounted to the metallic enclosure,
and further
showing the cooling system components of FIG. 16 mounted at the back of the
cabinet as a
spring loading feature to automatically push the drawer to the open position
when the
drawer's latch is released, the figure also showing a mounting rail for
receiving the slid of the
drawer;
[0053] FIG. 18 is a schematic view with measurements in inches of the
placement of two
TEm mode probes in the top surface of the enclosure shown in FIGS. 13-15;
[0054] FIG. 19 is a schematic view of the size and placement within the
drawer of FIG.
16 of two microstrip or "patch" antennae and their microstrip conductors
disposed between
respective antennae and the back of the drawer at which they will be connected
to SMA
connectors in one embodiment, for interconnection with other components;
[0055] FIG. 20 is diagram of field strength in an embodiment of an
enclosure with a
probe placed in the enclosure at a position in accordance with the diagram of
FIG. 19;
[0056] FIG. 21 is a lower scale drawing of the field intensity diagram of
FIG. 20 showing
a clearer view of the field intensity nearer the front and back walls of the
enclosure; and
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[0057] FIGS. 22A and 22B together present a block electrical and signal
diagram for a
multiple-drawer medical cabinet, such as that shown in FIG. 2, showing the
individual
multiplexer switches, the single RFID scanner. and power control;
[0058] FIG. 23 is a perspective view of a hospital crash cart having a
plurality drawers,
each of which may contain a tray of organized medical articles or the drawer
may contain
loose articles. The crash cart may be supplied to support a particular use in
a healthcare
facility, such as the intensive care unit, pediatrics, or other;
[0059] FIG. 24 is a top view of a sealed code tray showing the inventory
list sealed with
the medical articles of the tray. Labels have been used to advise on the
particular contents of
pockets of the tray;
[0060] FIG. 25 is a block diagram of a scanning and inventory system in
accordance with
aspects of the invention in which a code tray is placed within an enclosure
for scanning data
carriers contained on each medical article in the tray, the scanning results
compared to
databases, and the results of the scanning indicating what resupply efforts
area needed for the
tray;
[0061] FIG. 26 is a perspective view of a scanning enclosure in accordance
with aspects
of the invention that may be conveniently carried to various locations in a
healthcare facility
to scan and inventory trays and other containers, the enclosure providing a
robust
electromagnetic field within its cavity to activate and read all RFID tags
located therein;
[0062] FIG. 27 is a perspective view of a much larger enclosure for crash
carts that also
provides an electromagnetic field within to activate, detect, and read all
RFID tags in the
crash cart and provide their identifications;
[0063] FIG. 28 is a flow chart showing embodiments of methods to build a
medical
articles database, build a tray database, and scan and inventory a tray to
determine what
changes in the medical article contents of a tray need to be made to bring the
tray to the
inventory level required;
[0064] FIG. 29 is a flow chart of an embodiment of a method for scanning a
tray,
determining its contents, and indicating any changed needed to supply the tray
according to a
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predetermined inventory; also shown is a method for scanning medical articles
of the tray for
expired and recalled articles;
[0065] FIG. 30 shows a program feature in which the method of FIG. 29 may
be
controlled to search for expired articles within a selected time period;
[0066] FIG. 31 shows a program feature in which a graphic may be displayed
showing
the layout of a particular tray and showing a blinking indicator (asterisk in
this case) that
shows in which pocket a particular medical article is or should be placed; and
[0067] FIG. 32 shows a program feature in which the results of scanning a
tray are
displayed with lists multiple categories of the contents, such as expired,
recalled, missing,
and others.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0068] Referring now in more detail to the exemplary drawings for purposes
of
illustrating embodiments of the invention, wherein like reference numerals
designate
corresponding or like elements among the several views, there is shown in FIG.
1 a schematic
representation of a partial enclosure 20 in which a plurality of medical
articles 22 are stored,
each with a respective RFID tag 24 that has a unique identification number.
The partial
enclosure may comprise a drawer having a front 26, a left side 28, a right
side 30, a rear 32,
and a bottom 34. These articles are randomly distributed in the drawer with
the RFID tags
facing in various and random directions.
[0069] As used in regard to the embodiments herein, "reader" and
"interrogator" refer to a
device that excites an RFID tag and that may read or write/read. The data
capture device is
always referred to as a reader or an interrogator regardless of whether it can
only read or is
also capable of writing. A reader typically contains a radio frequency module
(a transmitter
and a receiver, sometimes referred to as a "transceiver"), a control unit and
a coupling
element (such as an antenna or antennae) to the RFID tag. Additionally, many
readers
include an interface for forwarding data elsewhere, such as an RS-232
interface. The reader,
when transmitting, has an interrogation zone within which an RFID tag will be
activated.
When within the interrogation zone, the RFID tag will draw its power from the
electrical/magnetic field created in the interrogation zone by the reader. In
a sequential RFID
system (SEQ), the interrogation field is switched off at regular intervals.
The RFID tag is
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programmed to recognize these "off" gaps and they are used by the tag to send
data, such as
the tag's unique identification number. In some systems, the tag's data record
contains a
unique serial number that is incorporated when the tag is manufactured and
which cannot be
changed. This number may be associated in a database with a particular article
when the tag
is attached to that article. Thus, determining the location of the tag will
then result in
determining the location of the article to which it is attached. In other
systems, the RFID tag
may contain more information about the article to which it is attached, such
as the name or
identification of the article, its expiration date, its dose, the patient
name, and other
information. The RFID tag may also be writable so that it can be updated.
[0070] As used in regard to the embodiments herein, "tag" is meant to refer
to an RFID
transponder. Such tags typically have a coupling element, such as an antenna,
and an
electronic microchip. The microchip includes data storage, also referred to as
memory.
[0071] FIG. 2 presents a representative medical dispensing cabinet 40
comprising a
plurality of movable drawers 42. In this embodiment, there are five drawers
that slide
outwardly from the cabinet so that access is provided to the contents of the
drawers. FIG. 1 is
a schematic diagram of a representative drawer that may be positioned within
the cabinet of
FIG. 2 for sliding outward to provide access to the drawer's contents and for
sliding inward
into the cabinet to secure the drawer's contents. The cabinet also comprises
an integral
computer 44 that may be used to control access to the drawers and to generate
data
concerning access and contents, and to communicate with other systems. In this
embodiment, the computer generates data concerning the number and type of
articles in the
drawers, the names of the patients for whom they have been prescribed, the
prescribed
medications and their prescribed administration dates and times, as well as
other information.
In a simpler system, the computer may simply receive unique identification
numbers from
stored articles and pass those identification numbers to an inventory control
computer that
has access to a database for matching the identification numbers to article
descriptions.
[0072] Such a cabinet may be located at a nursing station on a particular
floor of a health
care institution and may contain the prescriptions for the patients of that
floor. As
prescriptions are prepared for the patients of that floor, they are delivered
and placed into the
cabinet 40. They are logged into the integral computer 44, which may notify
the pharmacy of
their receipt. A drawer may also contain non-prescription medical supplies or
articles for
dispensing to the patients as determined by the nursing staff. At the
appropriate time, a nurse
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would access the drawer in which the medical articles are stored through the
use of the
computer 44, remove a particular patient's prescriptions and any needed non-
prescription
articles, and then close the drawer so that it is secured. In order to access
the cabinet, the
nurse may need to provide various information and may need a secure access
code. The
drawers 42 may be locked or unlocked, as conditions require.
[0073] The computer 44 in some cases may be in communication with other
facilities of
the institution. For example. the computer 44 may notify the pharmacy of the
health care
institution that a patient's prescription has been removed from the cabinet
for administration
at a particular day and time. The computer may also notify the finance
department of the
health care institution of the removal of prescriptions and other medical
articles for
administration to a particular patient. This medication may then be applied to
the patient's
account. Further, the computer 44 may communicate to administration for the
purpose of
updating a patient's Medication Administration Record (MAR), or e-MAR. The
medication
cabinet 40 computer 44 may be wireles sly connected to other computers of the
health care
institution or may have a wired connection. The cabinet may be mounted on
wheels and may
be moved about as needed or may be stationary and unable to move.
[0074] Systems that use RFID tags often employ an RFID reader in
communication with
one or more host computing systems that act as depositories to store, process,
and share data
collected by the RFID reader. Turning now to FIGS. 3 and 4, a system and
method 50 for
tracking articles are shown in which a drawer 20 of the cabinet 40 of FIG. 2
is monitored to
obtain data from RFID tags disposed with articles in that drawer. As mentioned
above, a
robust field of EM energy needs to be established in the storage site so that
the RFID tags
mounted to the various stored articles will be activated, regardless of their
orientation.
[0075] In FIGS. 3 and 4, the tracking system 50 is shown for identifying
articles in an
enclosure and comprises a transmitter 52 of EM energy as part of an RFID
reader. The
transmitter 52 has a particular frequency, such as 915 MHz, for transmitting
EM energy into
a drawer 20 by means of a transmitting antenna 54. The transmitter 52 is
configured to
transmit the necessary RFID EM energy and any necessary timing pulses and data
into the
enclosure 20 in which the RFID tags are disposed. In this case, the enclosure
is a drawer 20.
The computer 44 of an RFID reader 51 controls the EM transmitter 52 to cycle
between a
transmit period and a non-transmit, or off, period. During the transmit
period, the transmitted
EM energy at or above a threshold intensity level surrounds the RFID tags in
the drawer
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thereby activating them. The transmitter 52 is then switched to the off period
during which
the RFID tags respond with their respective stored data.
[0076] The embodiment of FIG. 3 comprises a single transmitting probe
antenna 54 and a
single receiving antenna 56 oriented in such a manner so as to optimally read
the data
transmitted by the activated RFID tags located inside the drawer 20. The
single receiving
antenna 56 is communicatively coupled to the computer 44 of the reader 50
located on the
outside of the drawer 20 or on the inner bottom of the drawer. Other mounting
locations are
possible. Coaxial cables 58 or other suitable signal links can be used to
couple the receiving
antenna 56 to the computer 44. A wireless link may be used in a different
embodiment.
Although not shown in the figures, those skilled in the art will recognize
that various
additional circuits and devices are used to separate the digital data from the
RF energy, for
use by the computer. Such circuits and devices have not been shown in FIGS. 3
and 4 to
avoid unneeded complexity in the drawing.
[0077] The embodiment of FIG. 4 is similar to the embodiment of FIG. 3 but
instead uses
two transmitting probe antennae 60 and 62 and three receiving antennae 64, 66,
and 68. The
configuration and the number of transmitting probe antennae and receiving
antennae to be
used for a system may vary based at least in part on the size of the enclosure
20, the
frequency of operation, the relationship between the operation frequency and
the natural
resonance frequency of the enclosure, and the expected number of RFID tags to
be placed in
it, so that all of the RFID tags inside the enclosure can be reliably
activated and read. The
location and number of RFID reader components can be dependent on the
particular
application. For example, fewer components may be required for enclosures
having a
relatively small size, while additional components, such as shown in FIG. 4,
may be needed
for larger enclosures. Although shown in block form in FIGS. 3 and 4, it
should be
recognized that each receiving antenna 56. 64, 66, and 68 of the system 50 may
comprise a
sub-array in a different embodiment.
[0078] The transmit antennae (54, 60, and 62) and the receive antennae (56,
64, 66, and
68) may take different forms. In one embodiment as is discussed in more detail
below, a
plurality of "patch" or microstrip antennae were used as the reader receiving
antennae and
were located at positions adjacent various portions of the bottom of the
drawer while the
transmit antennae were wire probes located at positions adjacent portions of
the top of the
drawer. It should be noted that in the embodiments of FIGS. 3 and 4, the RFID
reader 50
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may be permanently mounted in the same cabinet at a strategic position in
relation to the
drawer 20.
[0079] One solution for reliably interrogating densely packed or randomly
oriented RFID
tags in an enclosure is to treat the enclosure as a resonant cavity.
Establishing a resonance
within the cavity enclosure can result in a robust electromagnetic field
capable of activating
all RFID tags in the enclosure. This can be performed by building an enclosure
out of
electrically conductive walls and exciting the metallic enclosure, or cavity,
using a probe or
probes to excite transverse electric (TE) or transverse magnetic (TM) fields
in the cavity at
the natural frequency of resonance of the cavity. This technique will work if
the cavity
dimensions can be specifically chosen to set up the resonance at the frequency
of operation or
if the frequency of operation can be chosen for the specific enclosure size.
Since there are
limited frequency bands available for use in RFID applications, varying the
RFID frequency
is not an option for many applications. Conversely, requiring a specific set
of physical
dimensions for the enclosure so that the natural resonant frequency of the
enclosure will
equal the available RFID tag activating frequency will restrict the use of
this technique for
applications where the enclosure needs to be of a specific size. This latter
approach is not
practical in view of the many different sizes, shapes, and quantities of
medical articles that
must be stored.
[0080] Referring now to FIG. 5, a rectangular enclosure 80 is provided that
may be
formed as part of a medical cabinet, such as the cabinet shown in FIG. 2. It
may be embodied
as a frame disposed about a non-metallic drawer in such a cabinet. The
enclosure 80 is
formed of metallic or metallized walls 82, floor 83, and ceiling 84 surfaces,
all of which are
electrically conductive. All of the walls 82, floor 83, and ceiling 84 may
also be referred to
herein as "walls" of the enclosure. FIG. 5 also shows the use of an energy
coupling or probe
86 located at the top surface 84 of the enclosure 80. In this embodiment, the
probe takes the
form of a capacitor probe 88 in that the probe 88 has a first portion 94 that
proceeds axially
through a hole 90 in the ceiling 84 of the enclosure. The purpose of the
coupling is to
efficiently transfer the energy from the source 52 (see FIGS. 3 and 4) to the
interior 96 of the
enclosure 80. The size and the position of the probe are selected for
effective coupling and
the probe is placed in a region of maximum field intensity. In FIG. 5, a TEm
mode is
established through the use of capacitive coupling. The length and distance of
the bent
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portion 94 of the probe 88 affects the potential difference between the probe
and the
enclosure 80.
[0081] Similarly. FIG. 6 presents an inductive coupling 110 of the external
energy to an
enclosure 112. The coupling takes the form of a loop probe 114 mounted through
a side wall
116 of the enclosure. The purpose of this probe is to establish a TMoi mode in
the enclosure.
[0082] The rectangular enclosures 80 and 112 shown in FIGS. 5 and 6 each
have a
natural frequency of resonance fõ, shown in FIG. 7 and indicated on the
abscissa axis 118 of
the graph by fn. This is the frequency at which the coupled power in the
enclosure is the
highest, as shown on the ordinate axis 119 of the graph. If the injected
energy to the
enclosure does not match the fn frequency, the coupled power will not benefit
from the
resonance phenomenon of the enclosure. In cases where the frequency of
operation cannot
be changed, and is other than fn, and the size of the enclosure cannot be
changed to obtain an
fn that is equal to the operating frequency, another power coupling apparatus
and method
must be used. In accordance with aspects of the invention, an apparatus and
method are
provided to result in a forced resonance ff within the enclosure to obtain a
standing wave
within the enclosure with constructive interference. Such a standing wave will
establish a
robust energy field within the enclosure strong enough to activate all RFID
tags residing
therein.
[0083] When an EM wave that is resonant with the enclosure enters, it
bounces back and
forth within the enclosure with low loss. As more wave energy enters the
enclosure, it
combines with and reinforces the standing wave, increasing its intensity
(constructive
interference). Resonation occurs at a specific frequency because the
dimensions of the cavity
are an integral multiple of the wavelength at the resonance frequency. In the
present case
where the injected energy is not at the natural resonance frequency fin of the
enclosure, a
solution in accordance with aspects of the invention is to set up a "forced
resonance" in an
enclosure. This forced resonance is different from the natural resonance of
the enclosure in
that the physical dimensions of the enclosure are not equal to an integral
multiple of the
wavelength of the excitation energy, as is the case with a resonant cavity. A
forced resonance
can be achieved by determining a probe position, along with the probe length
to allow for
energy to be injected into the cavity such that constructive interference
results and a standing
wave is established. The energy injected into the enclosure in this case will
set up an
oscillatory field region within the cavity, but will be different from a
standing wave that
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would be present at the natural resonance frequency fn of a resonant cavity.
The EM field
excited from this forced resonance will be different than the field structure
found at the
natural resonance of a resonant cavity, but with proper probe placement of a
probe, a robust
EM field can nevertheless be established in an enclosure for RFID tag
interrogation. Such is
shown in FIG. 8 where it will be noted that the curve for the forced resonance
ff coupled
power is close to that of the natural resonance fn.
[0084] Turning now to FIG. 9, an enclosure 120 having two energy injection
probes is
provided. The first probe 86 is capacitively coupled to the enclosure 120 in
accordance with
FIG. 5 to establish a Tat mode. The second probe 114 is inductively coupled to
the
enclosure 120 in accordance with FIG. 6 to establish a TMoi mode. These two
probes are
both coupled to the enclosure to inject energy at a frequency ft that is other
than the natural
resonance frequency fn of the enclosure. The placement of these probes in
relation to the
ceiling 126 and walls 128 of the enclosure will result in a forced resonance
within the
enclosure 120 that optimally couples the energy to the enclosure and
establishes a robust EM
field within the enclosure for reading RFID tags that may be located therein.
The placement
of these probes in relation to the walls of the enclosure, in accordance with
aspects of the
invention, result in the forced resonance curve ff shown in FIG. 8.
[0085] Referring briefly to FIG. 10, an impedance matching circuit 121 is
shown that
functions to match the impedance of a source of energy 122 to the enclosure
120. The
impedance matching circuit is located between the coaxial cable 122 that feeds
activating
energy to the enclosure 120 and the capacitively coupled probe 88 through a
hole in the
metallic ceiling 126 of the enclosure. While the hole is not shown in the
drawing of FIG. 10,
the insulator 123 that electrically insulates the probe from the metallic
ceiling is shown. In
this case. the matching circuit 121 consists of only a resistive attenuator
124 used to reduce
reflections of energy by the enclosure 120. However, as will be appreciated by
those of skill
in the art, capacitive and inductive components are likely to exist in the
enclosure and in the
coupling 88. FIG. 11 on the other hand presents an impedance matching circuit
124 having
passive reactive components for use in matching the impedance of the coaxial
cable/energy
source 122 and the enclosure 120. In this exemplary impedance matching circuit
124, an
inductive component 125 and a capacitive component 127 are connected in
series, although
other configurations, including the addition of a resistive component and
other connection
configurations, are possible.
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[0086] Passive components such as resistors, inductors, and capacitors
shown in FIGS. 10
and 11 can be used to form matching circuits to match the impedances of the
energy source
and the enclosure. This will aid in coupling power into the enclosure.
However, the passive
matching circuit will improve the impedance match for a specific enclosure
loading, such as
an empty enclosure, partially loaded, or fully loaded enclosure. But as the
enclosure contents
are varied, the impedance match may not be optimized due to the variation in
contents in the
enclosure causing the impedance properties of the enclosure to change.
[0087] This non-optimal impedance match caused by variation in enclosure
loading can
be overcome by the use of an active impedance matching circuit which utilizes
a closed loop
sensing circuit to monitor forward and reflected power. Referring now to FIG.
12, an active
matching circuit 130 is provided that comprises one or several fixed value
passive
components such as inductors 132, capacitors 134, or resistors (not shown). In
addition, one
or several variable reactance devices, such as a tunable capacitor 134, are
incorporated into
the circuit; these tunable devices making this an active impedance matching
circuit. The
tunable capacitor 134 can take the form of a varactor diode, switched
capacitor assembly,
MEMS capacitor, or BST (Barium Strontium Titanate) capacitor. A control
voltage is
applied to the tunable capacitor 134 and varied to vary the capacitance
provide by the device.
The tunable capacitor 134 provides the capability to actively change the
impedance match
between the probe 140 and the enclosure 142.
[0088] To complete the active matching circuit, a dual directional coupler
144 along with
two power sensors 146 can be incorporated. The dual directional coupler 144
and the power
sensors 146 provide the ability to sense forward and reflected power between
the RFID
transceiver 148 and the active matching circuit 130 and enclosure 142.
Continuous
monitoring of the ratio of forward and reflected power by a comparator 150
provides a metric
to use to adjust the tunable capacitor 134 to keep the probe 140 impedance
matched to the
enclosure 142. An ability to continuously monitor and improve the impedance
match as the
contents of the enclosure are varied is provided with the active matching
circuit 130.
[0089] Referring now to the side cross-sectional view of FIG. 13, two
ceiling-mounted
160 probe antennae 162 and 164 are shown mounted within an enclosure, which
may also be
referred to herein as a cavity 166, which in this embodiment, operates as a
Faraday cage. As
shown, the Faraday cage 166 comprises walls (one of which is shown) 168, a
back 170, a
floor 172, a ceiling 160, and a front 161 (only the position of the front wall
is shown). All
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surfaces forming the cavity are electrically conductive, are electrically
connected with one
another, and are structurally formed to be able to conduct the frequency of
energy ff injected
by the two probes 162 and 164. In this embodiment, the cavity 166 is
constructed as a metal
frame 167 that may form a part of a medical supply cabinet similar to that
shown in FIG. 2.
Into that metal frame may be mounted a slidable drawer. The slidable drawer in
this
embodiment is formed of electrically inert material, that is, it is not
electrically conductive,
except for the front. When the drawer is slid into the cabinet to a closed
configuration, the
electrically conductive front panel of the drawer comes into electrical
contact with another
part or parts of the metallic frame 167 thereby forming the front wall 161 of
the Faraday cage
167.
[0090] The amount of penetration or retention into the cavity by the
central conductor
180 of each probe is selected so as to achieve optimum coupling. The length of
the bent
portion 94 of the probe is selected to result in better impedance matching.
The position of the
probe in relation to the walls of the cavity is selected to create a standing
wave in the cavity.
In this embodiment, the probe antennae 162 and 164 have been located at a
particular
distance D1 and D3 from respective front 161 and back 170 walls.. These probe
antennae, in
accordance with one aspect of the invention, are only activated sequentially
after the other
probe has become inactivated. It has been found that this configuration
results in a standing
wave where the injected energy waves are in phase so that constructive
interference results.
[0091] FIG. 14 is a front perspective view of the probe configuration of
FIG. 13 again
showing the two probe antennae 162 and 164 located in a Faraday-type enclosure
166 for
establishing a robust EM field in an article storage drawer to be inserted. It
should be noted
again that the Faraday cavity 166 is constructed as a metallic frame 167. In
this figure, the
cavity is incomplete in that the front surface of the "cage" is missing. In
one embodiment,
this front surface is provided by an electrically conductive front panel of a
slidable drawer.
When the drawer is slid into the cabinet, the front panel will make electrical
contact with the
other portions of the metallic frame 167 thereby completing the Faraday cage
166, although
other portions of the drawer are plastic or are otherwise non-electrically
conductive. In the
embodiment discussed and shown herein, the two probe antennae 162 and 164 are
both
located along a centerline between the side walls 166 and 168 of the frame
166. The
enclosure in one embodiment was 19.2 inches wide with the probe antennae
spaced 9.6
inches from each side wall. This centered location between the two side walls
was for
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convenience in the case of one embodiment. The probes may be placed elsewhere
in another
embodiment. In this embodiment, the spacing of the probes 162 and 164 from
each other is
of little significance since they are sequentially activated. Although not
shown, two receiving
antennae will also be placed into the Faraday cage 166 to receive response
signals from the
activated RFID tags residing within the cavity 166.
[0092] It will also be noted from reference to the figures that the probes
each have a bent
portion used for capacitive coupling with the ceiling 160 of the cavity, as is
shown in FIG.
13. The front probe 162 is bent forward while the back probe 164 is bent
rearward A
purpose for this configuration was to obtain more spatial diversity and obtain
better coverage
by the EM field established in the drawer. Other arrangements may be possible
to achieve a
robust field within the cavity 166. Additionally two probes were used in the
particular
enclosure 166 so that better EM field coverage of the enclosure 166 would
result.
[0093] FIG. 15 is a cutaway perspective side view of the dual probe
antennae 162 and
164 of FIGS. 13 and 14, also with the drawer removed for clarity. The front
probe 162 is
spaced from the left side wall by 1/2 X, of the operating frequency Ff as
shown. It will be noted
that the probes each have a bent portion used for capacitive coupling with the
ceiling 160 of
the enclosure 166 as shown in FIG. 13. The front probe 162 is bent forward for
coupling
with the more forward portion of the enclosure while the back probe 164 is
bent rearward for
coupling with the more rearward portion of the enclosure 166 to obtain more
spatial diversity
and obtain better coverage by the EM field in the drawer. Other arrangements
may be
possible to achieve a robust field and further spatial diversity and coverage
within the
enclosure.
[0094] FIG. 16 is a frontal upward-looking perspective view of the frame
167 forming a
Faraday cage 166 showing a portion of a drawer 180 that has been slidably
mounted within
the frame 167. The front metallic panel of the drawer has been removed so that
its sliding
operation can be more clearly seen. It will also be noted that the dual
ceiling mount probe
antennae 162 and 164 have been covered and protected by an electromagnetically
inert
protective cover 182. The drawer is formed of a non-metallic material, such as
a plastic or
other electromagnetic inert material having a low RF constant. The back 184 of
the drawer
has also been cut away so that a cooling system comprising coils 186 and a fan
188 located in
the back of the frame 167 can be seen. In this case, the drawer 180 is
slidably mounted to the
Faraday cage frame with metallic sliding hardware 190. The sliding hardware of
the drawer
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is so near the side of the frame 167 of the enclosure 166 and may be in
electrical contact with
the metallic slide hardware of the side walls 168 of the enclosure that these
metallic rails will
have only a small effect on the EM field established within the enclosure.
[0095] FIG. 17 is an upward looking, frontal perspective view at the
opposite angle from
that of FIG. 16; however, the drawer has been removed. The frame 167 in this
embodiment
includes a mounting rail 192 for receiving the slide of the drawer 180. In
this embodiment,
the mounting rail is formed of a metallic material; however, it is firmly
attached to a side 168
of the Faraday cage and thus is in electrical continuity with the cage. The
figure also shows a
spring mechanism 194 used to assist in sliding the drawer outward so that
access to the
articles stored in the drawer may be gained. The spring is configured to push
automatically
the drawer outward when the drawer's latch is released.
[0096] FIG. 18 is a schematic view showing measurements of the placement of
two TEoi
mode capacitive coupling probes 162 and 164 in the ceiling 160 of the frame
167 shown in
FIGS. 13-15. In this embodiment, the frequency of operation with the RFID tags
is 915
MHz, which therefore has a wavelength of 0.32764 meters or 1.07494 feet. One-
half
wavelength is therefore 0.16382 meters or 6.4495 inches. The length of the
capacitive
coupling bent portion 200 of each of the probes is 5.08 cm or 2.00 in. The
length of the axial
extension 202 of the probes into the enclosure is 3.81 cm or 1.50 in., as
measured from the
insulator 204 into the enclosure 166. The probe configuration and placement in
the
embodiment was based on an operation frequency of 915 MHz. In one embodiment,
the
enclosure 166 had a depth of 16.1 inches (40.89 cm), a width of 19.2 inches
(48.77 cm), and a
height of 3 inches (7.62 cm). It was found that the optimum probe placements
for this size
and shape (rectangular) enclosure and for the 915 MHz operating frequency
were: the front
probe was spaced from the front wall by 5.0 inches (12.7 cm) and the rear
probe was spaced
from the back wall by 5.0 inches (12.7 cm). As discuss above, the probes in
this embodiment
would only be activated sequentially.
[0097] FIG. 19 is a schematic view of the size and placement within the
enclosure 166 of
FIG. 16 of two microstrip or "patch" antennae 210 and 212 and their microstrip
conductors
214 and 216 disposed between the respective antennae and the back of the
enclosure at which
they will be connected to SMA connectors (not shown) in one embodiment. Feed
lines 58
(FIG. 3) may be connected to those SMA connectors and routed to the computer
44 for use in
communicating the RFID signals for further processing. The measurements of the
spacing of
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some of the microstrip components are provided in inches. The spacing of 9.7
in. is
equivalent to 24.64 cm. The width of the microstrip line of 0.67 in. is
equivalent to 17.0 mm.
The spacing of 1.4 in. is equivalent to 3.56 cm. Other configurations and
types of receiving
antennae may be used, as well as different numbers of such antennae. In the
present
embodiment, the receiving antennae are mounted on insulation at the bottom
inside surface of
the metallic enclosure frame 167 so that the receiving patch antennae are not
in contact with
the metal surfaces of the Faraday cage.
[0098] Referring now to FIG. 20, the field intensity or field strength in
the enclosure
discussed above is shown with the ordinate axis shown in volts/meter and the
abscissa axis
shown in meters. It will be seen from the diagram that the maximum field
intensity occurs at
about 5.0 inches (.127 m) which results from the probe positioned at 5.0
inches (12.7 cm)
from the front wall and at a 915 MHz operating frequency. Referring now to
FIG. 21, the
scale has been reduced although the large rise in field intensity can be seen
at 5.0 inches. It
can also be more clearly seen that the field intensity falls off at the right
wall but remains
strong very close to the left wall. Therefore in an embodiment, a second probe
was used that
was placed 5.0 inches (12.7 cm) from the right wall thereby resulting in a
mirror image field
intensity to that shown in FIG. 21. The two probes 162 and 164 are activated
sequentially
and are not both activated simultaneously. It will be noted that better EM
field coverage of
the enclosure 166 is obtained with the two probes and that RFID tags on
articles positioned
close to the front wall 161 will be activated by the front probe 162 and that
RFID tags on
articles positioned close to the rear wall 170 will be activated by the rear
probe 164 (see FIG.
13).
[0099] Although not intending to be bound by theory, in deriving the probe
location for
TE modes in a square or rectangular non-resonant cavity, the following
equation can be
useful:
[0100] N = 2 x L221
-
where: N = positive non-zero integer, for example 1, 2, 3, etc.
L1 = distance between probe and back wall
L, -= distance between probe and front wall
Xs = wavelength in the cavity
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[0101] L1 cannot be zero for TE modes, which implies that the probe for TE
mode
excitation cannot be at the front or back wall. For TM modes, the equation is
the same, but N
can equal zero as well as other positive integers. The probe position cannot
be 2g/2 from the
front or back wall. An L1 and an I-2 are chosen such that N can be a positive
integer that
satisfies the equation. For example, for the enclosure 166 discussed above:
L1 = 4.785 inches
L2 = 11.225 inches
kg = 12.83 inches
Therefore, N = 2 x 11.215 ¨ 4.785 =1.0
12.83
[0102] The actual enclosure had the probe located at a slightly different
location (5.0
inches) than that indicated by the equation (4.785 inches) which was possibly
due to the
insertion of a plastic drawer in the cavity, which introduces a change in the
phase from the
reflected signals. The equation above is set up such that the reflected phase
from both front
and back walls is equal, i.e., they are "in phase" at the probe location.
[0103] The wavelength in the enclosure, kg. can be calculated using
waveguide equations.
Equations for a rectangular cavity are shown below. The cutoff frequency is
required for this
calculation. The equations will change for a cylindrical cavity or for other
shapes.
[0104] The cutoff frequency is at the point where g vanishes. Therefore,
the cutoff
frequency in Hertz is:
1 (rivz + (Hz)
-2 ( ru-t-2
il
[0105]
(fc)trin ¨ ¨
2n- ,11176. a 2 b2
[0106] The cutoff wavelength in meters is:
[0107] (2,, L ___ 2 = __ (m)
i, in 2 (n.,2 l
+1¨
\a) 172
where: a = inside width
b = inside height
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m = number of 1/2-wavelength variations of fields in the "a" direction
n = number of 1/2-wavelength variations of fields in the "b" direction
c = permittivity
= permeability
[0108] The mode with the lowest cutoff frequency is called the dominant
mode. Since
TEiu mode is the minimum possible mode that gives nonzero field expressions
for
rectangular waveguides, it is the dominant mode of a rectangular waveguide
with a > b and
so the dominant frequency is:
[0109]
),0 - __ (Hz)
2aVeTte
[0110] The wave impedance is defined as the ratio of the transverse
electric and magnetic
fields. Therefore, impedance is:
[0111] ' = = jw,u jw,u
TE = ¨
H TE
jj/3,
[0112] The guide wavelength is defined as the distance between two equal
phase planes
along the waveguide and it is equal to:
21T 227
[0113] A
g 13 k
2
[0114] where ke=, ¨ + ¨1171" and
b
[0115] fi = 2 ke2
[0116] FIGS. 22A and 22B together provide a block electrical and signal
diagram for a
multiple-drawer medical cabinet, such as that shown in FIG. 2. In this case,
the cabinet has
eight drawers 220, shown in both FIGS. 22A and 22B. Each drawer includes two
top
antennae, two bottom antennae and a lock with a lock sensor 222 for securing
the drawer.
Signals to and from the antennae of each drawer are fed through an RF
multiplexer switch
224. Each RF multiplexer switch 224 in this embodiment handles the routing of
RF signals
for two drawers. RFID activation field and RFID received signals are fed
through the
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respective RF multiplexer switch 224 to a main RFID scanner 230 (see FIG.
22B). The
scanner 230 output is directed to a microprocessor 232 (see FIG. 22B) for use
in
communicating relevant information to remote locations, in this case by wired
connection
234 and wireless connection 236 (see FIG. 22B). Various support systems are
also shown on
FIGS. 22A and 22B, such as power connections, power distribution, back up
battery (see
FIG. 22B), interconnection PCBA. USB support (see FIG. 22A), cooling (see FIG.
22B), and
others.
[0117] In accordance with one embodiment, drawers are sequentially
monitored. Within
each drawer, the antennae are sequentially activated by the associated
multiplexer 224. Other
embodiments for the signal and electrical control systems are possible.
[0118] FIG. 25 shows an embodiment of an inventory management system 340
according
to aspects of the invention. An enclosure 342 is shown, which in this case
creates a Faraday
cage in that all the walls and top and bottom are electrically conductive
which isolates the
enclosure by preventing (or significantly attenuating) electromagnetic energy
from entering
or escaping the enclosure. The enclosure is fitted with a reader 344
configured to interrogate
RFID tags located within the enclosure, which may take the form of those
devices shown in
FIG. 1. The reader 344 is connected to a computer 346 through a connection
348. The
connection 348 may be a wired connection, wireless connection, or any other
suitable
connection for data transfer. In one embodiment, the physical body of the
computing system
may be attached to the enclosure 342. The computing system 346 has a non-
volatile memory
354 in which is stored at least one database ("db") which may be a local
database, or other.
The non-volatile memory 354 comprises one or more computer readable media
within the
computer system 346 and may be located within the computer itself or external
to the
computer. The memory is shown here as being outside the computer only for
clarity of
illustration in the discussion and is not meant to limit the invention in any
way. In another
embodiment, part or all of the local database may be held on a server 360. The
computing
system 346 is also connected to the remote database 360 at which is located a
first remote
database 362 and a second remote database 364. As in the local computer, these
remote
databases may be stored on a memory that is internal to the server or that is
external to the
server. Further, the server 360 may he located nearby the local computer 346
or may he
remote therefrom. By remote, it is meant that it may be in the same room, or
in the same
wing, or in the same facility, or may be in the cloud. Connection 366 to the
server 360 may
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likewise be a wired connection, wireless connection, or any other suitable
connection for data
transfer.
[0119] In one embodiment, the data held on the local database 352 may
depend on the
location/specialty/facility using computer system 346. For example, if the
computer system
346 were stationed in an emergency room ("ER"), the local database 352 may
hold only
information or data regarding medical articles, medical containers, and other
inventory most
used in an ER. In one embodiment, the remote database 362 at the server 360
may serve as a
main database and contain data for all medical articles, medical containers,
and other
inventory for all medical locations/facilities/specialties. The local database
352 may maintain
a copy of the portion of data held on the remote database 362 that is most
relevant to the
computer system 346, but can access the remote database 362 when encountering
medical
items, medical containers, or other inventory for different
facilities/specialties/locations.
[0120] The enclosure 342 has an opening 370 through which a tray 372 may be
slid into
the enclosure. The tray is placed completely within the enclosure so that the
front door 374
can be closed over the opening 370 to complete the Faraday cage of the
enclosure 342. The
tray includes a number of medical items 376 with each one having an RFID tag
378 attached.
As discussed previously, each RFID tag has a stored different identification
number
comprising a few bytes with a check digit. Manufacturers guarantee that each
serial number
is used only once. Some RFID tags have more complex codes for identifying the
RFID tag.
In this case, the tray 372 also has an RFID tag 280 attached to its outer
surface 382. The
reader 344 will read those identification numbers from the tags, communicate
them to the
computer which will compare them against one or more databases either locally
352 or
remotely through a server 362 and/or 364. The process of using the
identification numbers of
the tags is discussed below.
[0121] Medical item information may include information such as name, lot
code, date of
manufacture, expiration date, dosage, weight, color, and an image of the
medical article. In
one embodiment, the identification ("Ill") data may be partially made of drug
codes that
identify the drugs. As an example and not by way of limitation, the
identification data may
use the National Drug Code ("NDC") as part of its data allowing for easy
identification of the
attached medical item. Identification data may also have other identifying
codes that
establish the manufacturer, lot code, dosage, drug type, expiration date, etc.
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[0122] Shown in FIG. 26 is an enclosure 342 formed in accordance with
aspects of the
invention by which it is much smaller than an enclosure sized to be resonant
at the operating
frequency of RFID yet the EM field within the enclosure 342 is highly robust
and effective at
exciting and reading all RFID tags located therein. Because inventive aspects
are
incorporated, the enclosure is much smaller than other enclosures and is
therefore highly
desirable in areas where space is limited, such as a pharmacy in a healthcare
facility.
Although not shown, the front door 374 includes latching hardware to retain it
in a closed
when it is rotated upwards and put in use. A handle 384 assists in managing
the
configuration of the front door. The enclosure is formed of a metallic mesh or
solid metallic
material to establish a Faraday cage about trays that are slid within it for
scanning and
inventorying. The front door in this embodiment is also formed of a metallic
material and
closes the Faraday cage when the door 374 is closed. The RFID reader 344 is
shown in
dashed lines as are the electronics and battery 388 for the enclosure. The
electronics include
a processor, communications, wired and wireless connections, and a local power
source. In
another embodiment, an AC adapter may be included for using wall power.
Communications
ability over networks is provided.
[0123] The approximate volume for a resonant enclosure at an RFID operating
frequency
of 900 MHz is 3 ft. x 3 ft. x 3 ft. for a total of 27 cubic feet. In one
embodiment, the
enclosure 342 had the dimensions of 2.25 ft. wide by 1.6 ft. long by 0.88 ft.
high for an
approximate volume of 3.15 cubic feet, yet achieved an equally effective EM
field within the
enclosure at exciting and reading all RFID tags located therein. The
difference in sizes of the
two enclosures makes one formed in accordance with the invention more
attractive in many
situations where space is limited.
[0124] FIG. 27 presents another enclosure 390 of a much larger size so that
it can
accommodate crash carts 392 that do not include an internal RFID reader. In
this
embodiment, enclosure 390 has a ceiling 394 and a floor 396 which are at least
partially
metallic. The enclosure 390 also has two fixed side walls 398 and 400 and a
back (not
shown). Part of an RFID reader system 402 is shown within the enclosure. The
front part
404 of the enclosure is a hinged metallic door that, when closed, completes
the Faraday cage
of the enclosure 390. Instead of a door, the front 404 may be a flexible panel
that is also at
least partially metallic. Other approaches to providing a covering over the
front opening are
possible, provided that they complete the Faraday cage about the crash cart
392 once it is
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moved completely within the enclosure 390. In an alternative embodiment, all
four sides of
the enclosure may be made of flexible panels so that the enclosure can more
easily be moved
to another location. In one embodiment, the ceiling, floor, sides, back, and
front can all be
fitted with RFID readers/antennas 402 so that articles within the crash cart
having RFID tags
can be accurately identified.
[0125] It should be noted that use of a Faraday cage is highly beneficial
in healthcare
facilities due to the ubiquitous presence of medical articles that have RFID
tags. Without the
ability to electrically isolate the tray or crash cart to be read, an RFID
reader may read the
RFID tags of other pharmaceuticals on shelves outside the tray or crash cart
thereby giving
the operator the incorrect information that those external read articles are
in the tray or crash
cart.
[0126] The enclosure of FIG. 27 includes a ramp 406 that may or may not be
attached to
the floor 396 of the enclosure. The purpose of the ramp is to facilitate
rolling the crash cart
into the enclosure. Other means are possible.
[0127] FIG. 28 is a schematic diagram depicting an exemplary implementation
of an
inventory management system 410 according to an embodiment of the invention.
Starting at
the top, a database of medical articles managed by the system 410 is built
411. As an
example, a medication vial 412 on which an RFID tag 414 is mounted is being
registered
with the system 410 by entering the RFID tag's serial number 416 along with
the relevant
information 418 about the medication in the vial 412 into an "articles
database" 420 by the
computer 422. In this case, the computer comprises a processor 424, a display
426, and an
input device 428 which in this case is a keyboard. An RFID reader 430 obtains
the RFID
tag's serial number and assigns it to the medication information in the
medication to which
the RFID tag is mounted. In this case, the information about the medication
comprises: the
drug name, the dose, the volume, the expiration date, the manufacturer's name,
the lot
number, the NDC number, the UPC number, the tray number in which the
medication will be
store, and the location of the medication in the tray. Other information may
also be included.
This is then stored in the Articles Database or "Articles db" 420. Building
the Articles
database can be done in different ways and may be automated or may be pre-
prepared by the
medication manufacturer and given to the healthcare facility in electronic
form. The above is
repeated for all medications and other medical articles that may be placed in
a tray.
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[0128] The tray database, or "tray db" is built 440 in similar fashion. A
tray 442 is
supplied with its contents according to a Required Inventory list. Medical
articles are
collected and properly placed within the tray 442. In FIG. 27, only a few
medical articles are
shown for the purpose of clarity of the illustration. Many more articles may
be placed in the
tray. Each medical article within the tray includes an RFID tag 444. The fully
supplied tray
is placed within a Faraday cage 446, although this is not required if the tray
can be
sufficiently isolated from random tags, and a reader 448 reads the contents of
the tray. The
reader also reads an RFID tag 449 attached to the tray 442 itself. A computer
450 receives
the read tag numbers and stores them as a tray database 452. In the tray
database, the tray
RFID tag identification is connected with the type and name of the tray and
the RFID tag
numbers are connected with the medical articles placed in the tray. Trays may
have certain
categories, such as ER, or ICU, or pediatric, or other, and the tray database
will indicate that
category for the RFID no. of the tray RFID tag. As in the other systems, the
computer here
includes a processor 454, a display 456, and an input device 458 which in this
case is a
keyboard. The computer also comprises both random access memory and non-
volatile
memory, as do the other computers shown and described herein. In one
embodiment, the tray
database is relational in that it points to the medical articles database to
obtain more detailed
information about its inventory.
[0129] While the embodiment herein described refer to "trays," other
container types may
function equally well. It is not meant to confine the invention to any
particular type of
container unless so indicated.
[0130] A scanning and inventory system is shown at the bottom of FIG. 28
and includes
positioning the tray to be inventoried 460 within a RFID reader enclosure 446
that provides a
Faraday cage within itself. The tray to be inventoried 460 is positioned
entirely within the
Faraday case part of the enclosure 446 so that no external RFID tags will be
read by the
reader. 462. After closing the enclosure, the RFID reader 462 scans the tray
460, including
the RFID tag on the tray itself 490 and the tags on each of the medical
articles within the tray.
The identification numbers of each of the read RFID tags is communicated by
the reader to a
computer 464 similar to the other computers 424 and 450 described above. The
computer
includes a display 466, an input device 468 which, in this case, is a
keyboard, and a processor
470 forming part of the computer 464. In this embodiment, the computer
processor 470
compares the tray RFID tag serial no. to those stored in the tray database
452. If found in the
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tray database, that tray's inventory will be provided for further processing,
as described
below.
[0131] In accordance with an aspect of the invention, the enclosure
described above; i.e.,
enclosure 446, is a RFID scanning enclosure (see FIG. 26) configured with the
robust EM
field in accordance with the inventive aspects above. In particular, the
enclosure may be
configured as shown in FIGS. 13-17 and perform as described to achieve the
robust field for
detecting, activating, and reading all RFID tags within the enclosure.
[0132] Referring now to FIG. 29, a flow chart is provided that describes an
embodiment
of a method of scanning and inventorying a code tray in accordance with
aspects of the
invention. A tray is positioned in an enclosure 490 such as that provided by
FIGS. 13-17 and
26. An RFID reader then reads the RFID tag of the tray 492. The serial number
of the tray
RFID tag is then automatically compared to a tray database to determine if
this scanned tray
is in the database 494. If the tray is not in the database, an alarm is
provided 496. If the tray
is in the tray database, all RFID tags of medical articles in the tray are
read, and the names
and details of the medical article to which they are attached are
automatically compared 498
to the Required Inventory list of that tray. A determination is made if there
are any extra
articles in the tray that are not included in the stored tray database 450.
The access by the
program of multiple databases may be needed to perform this step. If extras
are detected, an
alarm is provided 496 so that those extra articles may be removed from the
tray. If no extra
articles are found, a determination is made if all required inventory articles
are in the tray
452. If articles are missing, a list of the missing articles is automatically
displayed 504 and
may be printed as needed. In one feature of an embodiment, the computer
program
performing the above steps may display 506 a graphical image of the tray 506
and indicate
where in the tray the missing articles should be placed. Such an image is
shown in FIG. 31
where a blinking asterisk 508 indicates where a medical article should be
placed. Many
different ways may be employed to assist in the placement of medical articles
in the tray.
Replacements for the missing medical articles are collected and the tray is re-
supplied 532 by
positioning the medical articles at the proper location in the tray.
[0133] If all articles are present in the tray, the computer program may be
informed of
such and formalities are then conducted. The electronic record for the
particular tray is
updated and an inventory sheet for the tray is printed for inclusion with the
tray. The tray is
then sealed and taken to the assigned location in the healthcare facility for
possible future use.
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However, in the event that the operator of the computer program performing the
described
scanning and inventory, the expiration dates of all medical articles in the
tray may be
checked. From the scan of the medical articles, the inventory dates are
compared against the
present date 510. In another aspect of the invention, the program may display
a screen asking
the operator which time period of expiration is desired for checking. Turning
now to FIG.
30, a screen shot 550 of the program is reproduced showing that in this
embodiment, a drop-
down list 552 of expiration periods is available to the operator. By selecting
any one of the
periods, the program will then search for and list 554 below the selected
period all medical
items expiring in that time period. If any medical items are listed 554, they
may be found in
the tray and replaced 514.
[0134] The program next proceeds to determining if any scanned medical
articles have
been recalled 514 by the manufacturer of the FDA, or otherwise. The comparison
of the
identification of the detected medical articles in the tray are compared to a
"Recalled"
database and if any articles match recalled articles, it is then determined if
a substitute
medical article exists 520. If none exists, an alarm is provided 522. If a
substitute article
does exist, a substitute is located 528 and supplied to the tray 532. If no
recalled articles exist
in the tray, in this embodiment, the inventory of the tray is updated in the
database 524; i.e.,
that a scan and verification of contents was just made, an inventory sheet is
printed, and the
tray is sealed 526. The tray may now be moved to a location in the healthcare
facility where
it may be put to use.
[0135] However, in the case above where medical articles had to be added to
the tray for
missing, expired, or recalled items, a rescan if performed 530 in this
embodiment. Such
scans, rescans, replacements, expiration, and recalls are all noted for one or
more databases
kept by the inventory re-supply system in accordance with the invention.
Because of the data
captured in scans and in the databases built by embodiments, many searches for
medical
articles may be performed. For example, if a pharmacy were concerned to locate
all
medications or other medical articles having an expiration date within one
month (see FIG.
30), a search of one or more databases of the embodiment above can be made to
find such
expiring articles. Another search on a database may be then made to track the
position of
those expiring articles; i.e., to determine if they are in a tray, and if so,
which tray it is, and in
what pocket of the tray. Such trays will expiring articles may be gathered,
and the re-supply
may be made.
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[0136] Referring now to FIG. 32, there is shown a computer program screen
shot 540 of a
listing of the articles detected in a tray during a scan of that tray in
accordance with aspects of
the invention. Various categories are shown including expiration 542 and
recall 544.
Incorrect articles 546 may be listed and for convenience, the entire Required
Inventory list
can be displayed as well as a check mark next to each one that is present and
not expired.
Many different forms of the display of results from scanning a tray, crash
cart, or other
container may be provided. FIG. 32 is just one embodiment.
[0137] Multiple databases may be employed in the system and method
described above.
According to one embodiment, the system 340 (FIG. 25) and the method 489 (FIG.
29) may
search one or more databases of medical article information matching the
identification data.
In one embodiment the identification data may be found in multiple databases
each database
containing different information. As by way of example and not limitation, the
name,
dosage, lot code and expiration date may be on one database while recall
status may be in
another database. In another embodiment all the medical item information may
be held in
one database which may have its information on other databases as backup. In
yet another
embodiment, medical item information may be stored on a local database within
the
computing device connected to the enclosure, and the local database may be
updated
periodically over a network connection from one or more remote databases.
[0138] The alarms that are provided may be done so visually, such as by
displayed on a
computer screen, audibly, such as through speaker sounds, and/or tactile by
vibrations. Other
means or combinations of means for communicating an alarm condition may be
used.
[0139] According to one embodiment, the data files within the databases
containing
medical information may take the form of a comma separated value list which
may have
multiple data fields and may look like "Name, Dosage, and Expiration." Other
serialized
formats may be used to contain the data, including but not limited to.
Extensible Markup
Language (XML), JavaScript Object Notation (JSON), etc. The data may also take
the form
of proprietary file formats created by medical article manufacturers.
Furthermore, the data
may contain a pointer or addresses to additional data providing additional
information about
the medical item or medical container. One example of additional information
may be a data
representation of a medical item's image. There are many different file or
data formats that
may be used to store medical information and any suitable format is
contemplated within this
invention. In one embodiment, multiple datasets using different data formats
containing
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medical item information may be used, each for a particular medical item
manufacturer or
distributor. A system may be configured to identify particular datasets based
on the
identification data from a data carrier (such as an RFID tag). In an
alternative embodiment, a
single data format may be used across all medical items independent of
manufacturers.
[0140] The inventory management system in accordance with the invention may
display
a list of every medical item missing from the medical container, any
additional medical items
not within the inventory list, any drugs with incorrect dosages, and any
expiration date and/or
status of every medical item within the container that is attached to a data
carrier with
identification data. In one embodiment as discussed above, the system may also
display an
image of each medical article that is missing, additional, incorrect dosage,
expired, recalled,
etc. That image of the medical article may make it easier for operators to
find the displayed
medical article or articles in the medical container. The image may be a
visual representation
of the medical article or its container which may include label colors. In an
alternative
embodiment, a diagram of the medical container may he provided, and the
location of the
medical article in the medical container may be highlighted in the diagram.
[0141] In one embodiment, an inventory management system and method in
accordance
with the invention may use color indicators to communicate any
differences/anomalies with
the articles within the medical container and the inventory list. The
inventory management
system and method may also provide expiration indicators. As an example, but
not by way of
limitation, expiration indicators may include displaying a countdown of the
number of days
left until expiration of a medical article. In another embodiment, a color
indicator using color
gradients or color coding may indicate the life of the medical article such as
green to red,
white to black, etc. Each end of the color/gradient spectrum may represent the
life or
expiration of the a medical article.
[0142] In further regard to FIG. 32, the display may use multiple windows.
Each window
may display different information regarding the contents of the scanned
medical container
such as a window for missing articles, a window for expired articles, a window
for incorrect
or additional articles not part of the container's inventory, a window for an
inventory list, a
window for recalled articles, and a window for aggregated information. Each
window may
have an image display, name, dosage, number of articles, and expiration or
recall status
indicator. Each window may also have a scroll bar for additional data that
does not fit in a
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single window. In an alternative embodiment, a single window may be used and
the user
may be provided with the ability to select what is displayed in the window.
[0143] In one embodiment, the inventory management system may allow for
registering
or creating specialized and/or individualized medical containers and
inventories for entry into
one or more databases. A user may fill a medical container with the correct
number of
medical articles (attached with data carriers) intended for the medical
container. The user
may insert the medical container into the enclosure of the inventory
management system,
such as described above in FIG. 28 at numeral 41. A user may instruct the
inventory
management system 410 through an input device 428, to register the container
under a certain
category, including specialized and/or individualized categories. The system
may read
identification data from every data carrier within the enclosure. In one
embodiment, a data
carrier is attached to the medical container itself. The system 410 may search
a database for
medical information associated with each identification data read from the
data carriers
within the container. The system builds an inventory list from the accessed
medical article
information and stores it on the database in association with the
identification data of the
specialized medical container.
[0144] The computers 422, 450 and 464 of FIG. 28 may take any suitable
form, including
but not limited to, an embedded computer system, a system-on-chip (SOC), a
single-board
computer system (SBC) (such as, for example, a computer-on-module (COM) or
system-on-
module (SOM)), a laptop or notebook computer system, a smart phone, a personal
digital
assistant (PDA), a server, a tablet computer system, a kiosk, a terminal, a
mainframe, a mesh
of computer systems, etc. The computers may be a combination of multiple
forms. The
computers may include one or more computer systems, be unitary or distributed,
span
multiple locations, span multiple systems, or reside in a cloud (which may
include one or
more cloud components in one or more networks).
[0145] In one embodiment, the computers 422, 450 and 464 of FIG. 28 may
include one
or more processors, memory, storage, an input/output (I/0) interface 3004, a
communication
interface, and a bus. Although this disclosure describes and illustrates a
particular computer
system having a particular number of particular components in a particular
arrangements, this
disclosure contemplates other forms of computer systems having any suitable
number of
components in any suitable arrangement.
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[0146] In one embodiment, processor includes hardware for executing
instructions, such
as those making up software. Herein, reference to software may encompass one
or more
applications, byte code, one or more computer programs, one or more
executable, one or
more instructions, logic, machine code, one or more scripts, or source code,
and vice versa,
where appropriate. As an example and not by way of limitation, to execute
instructions,
processor may retrieve the instructions from an internal register, an internal
cache, memory
or storage; decode an execute them; and then write one or more results to an
internal register,
an internal cache, memory, or storage. In one embodiment, processor may
include one or
more internal caches for data, instructions, or addresses. Memory may be
random access
memory (RAM), static RAM, dynamic RAM or any other suitable memory. Storage
maybe a
hard drive, a floppy disk drive, flash memory, an optical disk, magnetic tape,
or any other
form of storage device that can store data (including instructions for
execution by a
processor).
[0147] In one embodiment, storage may he mass storage for data or
instructions which
may include, but not limited to, a HDD, solid state drive, disk drive, flash
memory, optical
disc (such as a DVD, CD, Blu-ray, and the like), magneto optical disc,
magnetic tape, or any
other hardware device which stores may store computer readable media, data
and/or
combinations thereof. Storage may be internal or external to computer system.
[0148] The term "operationally responsive" is used herein for the purpose
of additional
clarity. It is believed that one skilled in the art would recognize that an
RFID device built for
operation at a particular nominal frequency would not be considered
operationally responsive
at a much different frequency, even though it may function somewhat, but at an
unacceptable
or "nonoperational" level. Therefore the term "not responsive" should be
sufficient but for
the avoidance of doubt, applicant has used the term not operationally
responsive, but believes
that it is synonymous with not responsive.
[0149] In one embodiment, input/output (I/0) interface, includes hardware,
software, or
both for providing one or more interfaces for communication between computer
system and
one or more I/0 devices. Computer systems may have one or more of these I/0
devices,
where appropriate. As an example but not by way of limitation, an I/0 device
may include
one or more mouses, keyboards, keypads, cameras, microphones, monitors,
display, printers,
scanners, speakers, cameras, touch screens, trackball, trackpad, biometric
input device or
sensor, or the like.
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[0150] In still another embodiment, a communication interface includes
hardware,
software, or both providing one or more interfaces for communication between
one or more
computer systems or one or more networks. A communication interface may
include a
network interface controller (MC) or a network adapter for communicating with
an Ethernet
or other wired-based network or a wireless NIC or wireless adapter for
communications with
a wireless network, such as a local wireless network. In one embodiment, bus
includes any
hardware, software, or both coupling components of a computer system to each
other.
[0151] "Medical article" is used in this document its broadest sense. For
example, a
medical article can be a medical device, a pharmaceutical drug, a lab
specimen, a blood
product, a human organ, a hospital scrub, a surgical instrument, a medical
implant, a sponge
or gauze pad, a healthcare institution code tray containing drugs to be
tracked, and a code tray
containing medical devices to be tracked.
[0152] As has been described, the various embodiments of the present
invention relates to
a system and method for medical article inventory and management. For purposes
of
explanation, specific nomenclature is set forth to provide a thorough
understanding of the
present invention. Description of specific applications and methods are
provided only as
examples. Various modifications to the embodiments will be readily apparent to
those skilled
in the art and the general principles defined herein may be applied to other
embodiments and
applications without departing from the spirit and scope of the invention.
Thus the present
invention is not intended to be limited to the embodiments shown, but is to he
accorded the
widest scope consistent with the principles and steps disclosed herein.
[0153] Although REID tags arc used herein as an embodiment, other data
carriers that
communicate through electromagnetic energy may also be usable.
[0154] While the invention has been described in connection with what is
presently
considered to be the most practical and preferred embodiments, it is to be
understood that the
invention is not to be limited to the disclosed embodiments and elements, but,
to the contrary,
is intended to cover various modifications, combinations of features,
equivalent
arrangements, and equivalent elements included within the scope of
the appended
claims.
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[0155] Unless the context requires otherwise, throughout the specification
and claims that
follow, the word "comprise" and variations thereof, such as, "comprises" and
"comprising"
are to be construed in an open, inclusive sense, which is as "including, but
not limited to."
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