JP5985500B2 - RFID-compliant drawer cooling system - Google Patents

Description

  This application incorporates US application 61 / 419,762 dated December 3, 2010 and US patent application No. 12 / 631,861 dated December 7, 2009, and further dated February 9, 2010. Incorporating US application 61 / 302,912, all of these US patent applications are hereby incorporated by reference herein.

  The present invention relates generally to the field of drug management, and more particularly to a drug management system and related methods that provide drug identification, tracking and temperature management.

  For many years, drug removal systems have been used. The initial goal of such a system was to reduce medication errors associated with manual distribution and high maintenance costs associated with large inventory. The current system has many advantages, but this benefit is the cost reduction associated with dispensing and distribution, improved inventory management, physical management, automated documentation, further reduction of errors, and expertise Including reducing the workload of pharmacists and nurses.

  In large-scale medical facilities, the main inventory of medicines is often in a storage location far away from the patient who is the user of the medicine. Various systems have been proposed and put into practical use in order to deliver pharmaceutical products safely and accurately from these storage locations to patients. In an early system, called the “cart change” system, drug carts are transported to a medical facility nurse station away from the central pharmacy and periodically exchanged with a fully supplied cart. Typically, these carts contain a 24-hour supply of medication sorted into individual drawers for each patient. The “used” cart is returned to the central pharmacy in the supply area where the next 24 hours of medication will be replenished. The sleeping pills are stored in a locked box on the floor, requiring two nurses to have separate keys and a written record.

  For some medications, cart change systems are still in use, but the task of processing many new orders from the central pharmacy during the day and returning a large amount of unused medication is significant. It will be labor intensive. The restocking of these drugs needs to be done accurately and is very time consuming. As a result, the use of automated processor-based drug cabinets on nurse floors has increased. Each cabinet processor monitors access to medication in these fixed cabinets, and the current on-hand inventory and what needs to be replenished is sent to a central processing unit at the central pharmacy location. The initial purpose of these processor-based take-out cabinets is to manage sleeping pills more conveniently and to have a common drug “floorstock”, where nurses can place pharmacies on exchange carts We were able to make the first dose of the new prescription drug requested from the floorstock while waiting for 24 hours of replenishment coming from or specially ordered.

  Referring now to FIG. 23, a medication cabinet 300 typically includes an integrated touch screen 304 coupled to a control unit 306, a communication link 308 for linking with a central server 310, and one or more carts. A communication link 314 for linking with 316. Such communication links 308 and 314 are shown schematically as connections for wired communications, but as will be appreciated by those skilled in the communications arts, transmitters and receivers for wireless communications (eg, RF , IR, sound). In addition to data entered via communication links 308 and 314, data is entered manually via a virtual keyboard included in touch screen 304. The communication link 308 is a connection with the server 310 and, if necessary, allows the medication cabinet 300 to interface with the database 320 that the server 310 accesses for real-time updates. It also provides the information needed to guide pre-authorized health care attendants when formulating patient medications, solutions for intravenous injection, and the like. In another embodiment shown in FIG. 24, an actual keyboard 322 or keypad or similar device may replace or supplement the functionality of the touch screen 304.

  These processor-based medication cabinets 300 provide the ability to store most of the medication that patients on that floor may need day and night. In many cases, these medications are stored in pockets in a locked drawer. Once the nurse has entered his personal ID and the ID of a particular patient, the nurse confirms the overall medication approved by the selected patient, and at a particular time, commonly referred to as a “medication due drug” Check for drugs that are due. Next, the central pharmacy's job is to monitor the on-hand stock of medication stored in the cabinet and replenish the medication levels at regular intervals. An important advantage of this process is that no unused drugs are returned to the central pharmacy. This means that the first administration (and subsequent administrations) is readily available.

  In addition, there are a number of situations that still require the drug to be delivered from a central pharmacy. For example, to avoid medication errors, the nurse does not prepare by attaching a so-called piggyback drug bag to a standard diluent bag, but for safety reasons, intravenous fluids containing the drug (IVs) can be mixed at the pharmacy and delivered to the floor. There are also special drugs or drugs that are not frequently used, drugs that have a short life, drugs that require refrigeration, or drugs that require special handling from a pharmacy. Many drugs and vaccines are temperature sensitive and have strict storage requirements. Some medical compositions with low stability need to be kept at low temperatures, perhaps in the range of 2-6 degrees Celsius. Typically, a separate drug cabinet with a cooling unit is used when cooling is required.

  Current drug cabinets are either entirely cooled or not cooled entirely. Depending on the cabinet, all drawers in those cabinets receive the same cooling or lack cooling. Cooling is relatively expensive because of the need for power and cooling equipment. The overall drug cabinet is expensive and relatively large, each with its own computer equipment, power equipment, and communication equipment, each occupying valuable floor space. In the prior art, in many cases where some patients require medication that must be refrigerated until administration and medication that should not be refrigerated, there are two cabinets where one is cooled and the other is not. is necessary. In some cases, although only a small portion of the cabinet requires cooling, cooling is provided to the entire cabinet, with the majority of the cabinet being empty. This is an inefficient approach. Current systems provide an effective method for providing refrigerated medication, but reduce the cost of drawers in the cabinet and allow more items to be singulated with both cooled and uncooled drawers. It would be desirable to be able to hold it in one cabinet. Thus, it would be beneficial to have both a cooled drawer and an uncooled drawer in a single cabinet from both a cost and space perspective.

  It is also desirable to be able to monitor the temperature of a refrigerator or other temperature controlled cabinet or drawer and record the monitored temperature in a log over a long period of time. Continued such monitoring and recording may be strongly recommended or required by several health care mechanisms such as the Joint Commission on Accretion of Healthcare Organizations (JCAHO). It is also desirable for a drug that requires temperature control to automatically provide an alarm if the temperature (or relative humidity) is outside an acceptable range.

  The handling of temperature-controlled drugs is also a manual process with regard to determining which drugs need temperature control and under what conditions the drugs must be stored. Such manual handling, inspection and investigation takes time. To increase efficiency, it would be desirable to provide a system and method that can automate at least some of these requirements.

  Thus, those skilled in the art will recognize the need for automated systems and methods to recognize which drugs need refrigeration, determine what level of cooling is needed, and achieve such cooling. Understand. Those skilled in the art also understand the need to monitor the temperature of a refrigerator or other temperature controlled cabinet or drawer that holds temperature controlled medication and log the monitored temperature over time. Furthermore, those skilled in the art understand that the need to provide both a cooled drawer and an uncooled drawer in a single cabinet to reduce both cost and space requirements. The present invention satisfies these and other needs.

  Wireless automatic identification (“RFID”) performs individual identification using electromagnetic energy (“EM energy”) to prompt the response device (known as an RFID “tag” or transponder) Some provide further stored data. RFID tags typically include a semiconductor device having one or more conductive traces that form a memory, a circuit, and an antenna. Typically, an RFID tag acts as a transponder and provides information stored in a semiconductor device memory in response to an RF interrogation signal received from a reader, also called an interrogator. Some RFID tags include security means such as passwords and / or encryption. In addition, many RFID tags permit writing and storage of information in a semiconductor memory via an RF signal.

  The RFID tag may be incorporated or attached to the tracked item. The tag may be attached to the outside of the article with adhesive, tape or other means, and the tag may be inserted into the article, such as if it is included in the packaging, or in the container of the article Or may be sewn into clothing. An RFID tag is manufactured with a unique individual identification number, and this individual identification number is typically a simple serial number of several bytes with a check digit attached. This individual identification number is incorporated into the tag during manufacture. The user cannot change this serial number / individual identification number, and the manufacturer ensures that each serial number is used only once. This configuration is the low cost limitation of this technology in that the RFID tag is read-only and responds to the challenge signal only with the individual identification number. Typically, the tag responds continuously to the individual identification number. Data cannot be sent to the tag. These tags are very low cost and are mass produced.

  Such read-only RFID tags are typically permanently attached to the item being tracked, and once attached, the tag serial number is associated with the host item in the computer database. For example, a particular type of drug may be contained in hundreds or thousands of vials. RFID tags are attached to each vial at the time of manufacture or when the vial is received at a health care organization. Each vial with a permanently attached RFID tag is checked in the health care organization's database as it is received. The RFID individual identification number may be associated with other information in the database, such as the type of drug, the size of the vial dose, and possibly the expiration date of the drug. Thereafter, when the RFID tag of the vial is interrogated and the individual identification number is read, the health care organization database can match the individual identification number with the stored data for the vial. Next, along with the contents of the vial, any other characteristics that have been stored in the database can be determined. This system requires medical institutions to maintain a comprehensive database of inventory items rather than incorporating such data into RFID tags.

  The purpose of the tag is to associate the tag with the item during the lifetime of the item in a particular facility, such as a manufacturing facility, transport vehicle, medical facility, or storage area, so that the item is located when the item moves. To be identified, identified, and tracked. For example, if you always know where a medical article is in a medical facility, it can be very easy to identify the location of medical supplies that are needed when an emergency occurs. Similarly, tracking items through a facility can assist in a more efficient pick-up and inventory management system and can facilitate improved work flow at the facility. In addition, expiration dates can be monitored and older upcoming items can be moved to the front of the line for immediate retrieval. Thereby, favorable inventory management and cost reduction are achieved.

  Other RFID tags are writable and information about the items to which the RFID tag can be attached can be programmed into the individual tags. If the facility's computer server is not available, this may offer a different advantage, but such a tag increases in cost depending on the size of the memory in the tag. Programming each of the tags to have information contained in the article to which the tag is attached incurs additional costs.

  The RFID tag may be applied to a container or article to be tracked by the manufacturer, recipient, etc. When a manufacturer applies a tag to a product, the manufacturer also provides a respective database file that links each individual identification number of the tag and the contents of each article. The database supplied by the manufacturer can be distributed to the customer in a file format that can be easily imported into all of the customer's databases, thereby saving the customer the cost of creating the database.

  Many RFID tags currently in use are passive and do not have a battery or other stand-alone power supply, but instead are interrogating supplied by an RFID reader to provide power to operate the tag. energy). Passive RFID tags require a certain frequency range and a certain lowest intensity energy electromagnetic field to achieve tag operation and transmission of stored data. Another option is an active RFID tag, but such a tag requires an attached battery to provide power to operate the tag, increasing the cost of the tag and making it useful for many applications. Becomes undesirable.

  Depending on the RFID tag application requirements, such as the physical size of the item to be identified, the location and easy access to the item, the tag may have to be read from a short or long range by an RFID reader. Such distance can vary from a few centimeters to over 10 meters. Further, in the United States and other countries, the frequency range in which such tag operation is permitted is limited. As an example, low frequency bands such as 125 KHz and 13.56 MHz may be used for RFID tags in some applications. In this frequency range, electromagnetic energy is rarely affected by liquids and other dielectric materials, but is limited in that the interrogation distance is reduced. At higher frequency bands where RFID use is allowed, such as 915 MHz and 2.4 GHz, the RFID tag interrogation distance will be longer, but the tag will be released more quickly if the material to which the tag is attached changes. Adjust. It was found that RFID tags provided at close intervals detuned from each other when the interval between the tags was reduced at these high frequencies.

  There are many common situations where RFID tags are installed in enclosures. Some of these enclosures may have a metal surface or metallized surface completely or partially. Examples of enclosures include metal enclosures (eg, shipping containers), partial metal enclosures (eg, vehicles such as aircraft, buses, trains and ships with housings made of a combination of metal and other materials) and non- There are metal enclosures (for example, wooden warehouses and buildings). Examples of items with RFID tags that may be installed in these enclosures include items that are not in containers, packaged items, compartments in warehouses, inventory in buildings, various items in retail stores, and in vehicles Various portable items (eg, individual life-saving equipment such as occupant identification cards and tickets, luggage, cargo, life jackets and masks).

  The reading range of the RFID tag (ie, the range of the interrogation signal and / or response signal) is limited. For example, some types of passive RFID tags have a maximum range of about 12 meters, and this range may only be obtained in ideal free space conditions with favorable antenna orientation. At present, the observed tag range is often 6 meters or less. Thus, some of the enclosures described above may have dimensions that are well beyond the read range of individual RFID tags. If the RFID reader cannot be placed in close proximity to the target RFID tag in such an enclosure, the tag will not be activated and read. In addition, the metal surface of the enclosure is a serious obstacle for RF signals that need to be exchanged between the RFID reader and the RFID tag, and the RFID tag located behind the metal surface of the enclosure is difficult to detect. It becomes difficult or impossible.

  In addition to the above, the detection range of RFID systems is typically limited to short distances by signal strength, often less than about 30 centimeters for 13.56 MHz systems. Therefore, a portable reader unit can be used to detect all tagged items, especially if the tagged item is stored in a space significantly larger than the detection range of a stationary or fixed single reader antenna. It may be necessary to go through a group of accessories. Alternatively, a large reader antenna with sufficient power and range to detect a large number of tagged items may be used. However, such antennas are cumbersome and can increase the range of radiated power beyond an acceptable range. Furthermore, these reader antennas are often installed in shops and other places where the value of space is high, and using such large reader antennas is expensive and inconvenient. As another possible solution, multiple small antennas may be used, but if space is at a premium and it is preferable or required to hide the wiring, such a configuration is It can be troublesome.

  For medical supplies and devices, accurate tracking and inventory management so that the location of RFID-tagged devices and articles can be identified immediately when required and can be identified for other purposes, such as expiration dates Development of a system and take-out system is desired. In the case of medical supplies and take-out cabinets used in medical facilities, a large number of medical devices and articles are in close proximity to one another, for example, multiple drawers. Such cabinets are typically metallic and it can be difficult to use an external RFID system to identify stored items. In some cases, such cabinets are locked because sleeping pills or other medical items or devices with high theft rates are in the cabinet. Thus, manually identifying the contents of a cabinet is difficult due to the need for access management.

  Providing an internal RFID system in such a cabinet can also be difficult. If the internal items are randomly placed in the cabinet, the RFID system must ensure that there are no “dead zones” that the RFID system cannot reach. In general, the dead zone is an area where the level of coupling between the RFID reader antenna and the RFID tag is not sufficient for the system to successfully read the tag. The presence of such a dead zone can be caused by the orientation in which the tag and reader antenna are in a vertical plane. As described above, since the article placed in the dead zone is not detected, tracking of the tagged article becomes inaccurate.

  In the medical field, it is often necessary to read a large number of tags attached to items in such an enclosure, and as mentioned above, such an enclosure has limited access for security reasons. . The physical dimensions of the enclosure need to be changed to accommodate multiple items or items of different sizes and shapes. In order to accurately identify and count such closely placed medical articles or devices, it surrounds all such stored articles and devices, ensuring that all tags are activated and read. In addition, a stable electromagnetic energy field at an appropriate frequency within the enclosure must be provided. Such medical devices may have RFID tags attached to the outside of the container, with RFID tags (and associated antennas) oriented in an upward, sideways, downwards, or other pattern in a random pattern. It may be stored in various orientations in the attached state.

  Generating such a stable EM energy field is not an easy task. If the enclosure has a size that resonates at the operating frequency, a resonant standing wave can be generated within the enclosure, and therefore tends to generate a stable EM field. However, in the RFID field, the usable operating frequency is strictly controlled and limited. It has been found that an enclosure is desirable for storing articles that do not have a resonant frequency that matches one of the allowed RFID frequencies. Thus, a stable EM field must be established in another way.

  Furthermore, efficient energy transfer becomes important when EM energy is introduced to such an enclosure to read internal RFID tags. Under static conditions, the input or injection of EM energy into the 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 skilled in the art, such an impedance matching circuit or device maximizes the transfer of power to the enclosure while minimizing power reflections from the enclosure. If the impedance of the enclosure changes by introducing or removing articles from the enclosure, the static impedance matching circuit may not provide optimal energy transfer to the enclosure. If the energy transfer and resulting RF field strength in the enclosure is below a threshold level, some or many of the tags on the items in the enclosure will not be activated and the inventory system will not be Become efficient.

  Keeping EM energy usage to a minimum or at least minimizing it is a goal of many medical facilities. The use of high-power readers to locate and extract data from RFID tags is generally not desirable in medical facilities, but may be acceptable in warehouses with a small number of workers and aircraft cargo holds. is there. It is not desirable to emit a wide EM energy beam in a large area where the EM energy may fall outside of an adjacent more sensitive area. In order to obtain the necessary individual identification information from the tag, the purpose is to improve efficiency when operating the reader. In many cases where RFID tags are read, a handheld reader is used. Such a reader transmits a relatively wide energy beam that reaches all RFID tags at a particular location. Although the final result of activating and reading each tag can be achieved, the energy transfer is not controlled except by the user aiming. In addition, since this is a manual system that requires the service of one or more personnel, it may not be desirable in a facility with a limited number of staff.

  Thus, those skilled in the art understand that a drug cabinet that provides both cooled and uncooled drawers is needed to reduce cost and space requirements and accommodate various types of drugs. doing. Also, the need for an RFID tag reading system that efficiently uses energy to activate and read all RFID tags in the enclosed area is also appreciated. It is also understood that there is a further need to establish a stable EM field in the enclosure to activate and read tags that are randomly oriented. In addition, the need for an automated system for identifying items stored in metal cabinets without the need to access the cabinet is also appreciated. The present invention fulfills these and other needs.

  Briefly and broadly, the present invention relates to a system that provides both cooled and uncooled drawers in a single drug cabinet while using RFID for medical product identification and tracking records. . In particular, a cabinet for storing medical products is provided, the cabinet comprising a frame having a plurality of openings for receiving drawers, the frame having a first for receiving a first drawer. A conductive cage is provided around the opening, the cage having a front locate and a rear located at the opening. The cabinet has a plurality of drawers, each drawer is configured to be received by a respective opening, and can enter and exit from each opening, and a first drawer is received in the opening having the cage. It is configured to be. A thermoelectric cooling (“TEC”) device is configured to provide cooling to only one drawer, and the second opening adjacent to the first opening does not have a cooling device. Thermal insulation is disposed between the first and second openings and is configured to prevent the cooling from the thermoelectric cooling device from reaching the drawer of the second opening. An RFID reader is arranged in the cabinet and is configured to read data from an RFID tag located in the cabinet.

  According to a further detailed feature, the TEC device is mounted on the frame such that each drawer moves towards the TEC device when moving to the closed position and away from the TEC device when moving to the open position. It is done. Each TEC drawer includes a TEC device enclosure formed at the back of the drawer, the TEC device enclosure configured to receive the TEC device into the enclosure when the drawer is in the closed position, thereby The depth of becomes smaller. The TEC device enclosure includes a cooling diffuser configured to help circulate cooling from the TEC device equally throughout the drawer. Further, the drawer having the TEC device enclosure further comprises a partition configured to separate the medical items contained in the drawer from each other, and the partition prevents the cooling from the TEC device from being circulated equally throughout the drawer. These partitions are configured so that they do not.

  In another detailed aspect, the RFID reader comprises an antenna that protrudes into the drawer, the drawer comprises a TEC enclosure that receives a TEC device when the drawer is in the closed position, and the enclosure is tagged with the tag located in the drawer It is arranged so as not to interfere with the operation of the antenna for reading the article. The first drawer can be slid into and out of the first opening of the cabinet, and this drawer is in the conductive cage of the first opening when the drawer is slid into position in the cabinet. It has a conductive front panel that contacts it. In the first drawer, the conductive cage around the drawer is closed by forming a portion located at a position in contact with the conductive cage from a conductive material.

  In yet another aspect according to the present invention, the configuration in the cabinet such that the RFID reader creates a resonance in the drawer to provide a stable electromagnetic field for reading the tagged medical article housed in the drawer. Have an arrangement.

  Another detailed aspect is that the first drawer is non-conductive except at the point where it contacts the cage to close the cage around the drawer. Furthermore, a temperature sensor is arranged for measuring the temperature in the drawer.

  The features and advantages of the present invention will be more readily understood from the following detailed description, which should be considered in conjunction with the accompanying drawings.

1 is a schematic representation of a drawer showing storage of a plurality of medical articles randomly positioned in the drawer, each of the medical articles having an integrated RFID tag that is randomly oriented, and may be positioned within a medical retrieval cabinet. FIG. 2 is a perspective view of a drug removal cabinet with five drawers, one of the drawers is similar to the schematic of FIG. 1, and the cabinet periodically maps any RFID tag placed on an article stored in the cabinet. FIG. 3 is a perspective view of a drug removal cabinet with an integrated computer for managing access to the cabinet by performing reading and performing inventory tracking and reporting personally identified items to a remote computer. An RFID reader transmits operating EM energy into a drawer that includes an RFID tag using a single transmit antenna and receives data output from an RFID tag that is operated using a single receive antenna. FIG. 6 is a block flow diagram illustrating an embodiment for receiving data from an operational RFID tag to manage and process transmission of operational energy. An RFID reader transmits operating EM energy into a drawer including an RFID tag using two transmitting antennas and receives data output from an RFID tag operated using three receiving antennas, as shown in FIG. FIG. 4 is a block flow diagram similar to FIG. 3 illustrating an embodiment in which a computer receives data from an operational RFID tag to manage and process the transmission of operational energy. FIG. 5 shows an enclosure having a single probe and connector configured to inject EM energy into the enclosure and excite TE mode. FIG. 5 shows an enclosure having a single probe and connector configured to inject EM energy into the enclosure and excite TM mode. It is a diagram showing a plot showing the relationship between the enclosures coupled power and the frequency of the resonant enclosure, F _n is the natural resonant frequency of the enclosure. FIG. 7 is a plot showing the relationship between enclosure coupling power (ordinate axis) and frequency (abscissa axis), where f _f is the forced resonant frequency, or referred to as the frequency not equal to the enclosure resonant frequency; f _n is the natural resonance frequency of the enclosure that indicates the establishment of a stable field of the coupling power of the enclosure at the f _f frequency. FIG. 3 shows an enclosure in which each of two probes for injecting EM energy into an enclosure has a connector, one probe is a TM probe and the other probe is a TE probe. FIG. 5 shows a probe, connector and attenuator used to increase impedance matching between the probe and the enclosure. FIG. 3 shows a probe, connector and passive matching circuit used to increase impedance matching between the probe and the enclosure. FIG. 4 illustrates an active matching circuit connected between a probe and a transceiver installed in an enclosure, the active matching circuit providing a closed loop variable matching circuit to enhance impedance matching between the probe and the enclosure A tuning capacitor, a bi-directional coupler, multiple power sensors and a comparator. Drawer with drawers removed for clarity, showing the placement of two probe antennas in a “ceiling mounted” configuration to establish a stable EM field for the drawer when the drawer is in place in the cabinet 2 is a side cross-sectional view of the cabinet of FIG. FIG. 14 is a perspective view of a metallic enclosure showing the probe configuration of FIG. 13 again showing two probe antennas for establishing a stable EM field for the drawer to be inserted. FIG. 15 is a cutaway perspective side view of a metal enclosure or frame with the dual probe antenna of FIGS. 13 and 14 attached with the drawer removed for clarity. A cooling system with a cutout plastic drawer in place in a metal enclosure, further showing a double ceiling mounted probe antenna protected by an electromagnetically inert protective cover, mounted on the back of the cabinet near the back of the drawer FIG. 15 is a front perspective view of the view of FIG. 14 further illustrating the components, wherein the drawer also shows a partial view of the drawer slide mechanism for facilitating when sliding the drawer between the open and closed positions in the cabinet. The drawer front panel and the back panel are in a state cut out in FIG. FIG. 17 is a front perspective view from the opposite angle to that of FIG. 16 with the plastic drawer completely removed, showing a dual ceiling mounted probe antenna protected by an EM inert protective cover attached to a metal enclosure. 16 further shows the cooling system component of FIG. 16 attached to the back of the cabinet as a spring loaded feature to automatically push the drawer to the open position when the drawer latch is released, for receiving the drawer slide The mounting rail is further shown. FIG. 16 is a schematic representation of measurements in inches of the placement of two TE ₀₁ mode probes on the top surface of the enclosure shown in FIGS. FIG. 17 is a schematic representation of the size and placement of two microstrip or “patch” antennas and their microstrip conductors in the drawer of FIG. 16, wherein the microstrip conductors, in one embodiment, and other components, Provided between the back of the drawer connected to the SMA connector for interconnection. FIG. 20 is a field strength diagram of an embodiment of an enclosure in which the probe according to the diagram of FIG. 19 is placed in place in the enclosure. FIG. 21 is a lower scale illustration of the field strength diagram of FIG. 20 showing that the field strength is more pronounced closer to the front and back walls of the enclosure. FIG. 3 is a block electrical diagram of a multiple drawer medical cabinet, such as that shown in FIG. 2, showing individual multiplexer switches, a single RFID scanner, and a power controller. FIG. 3 shows a medication administration cabinet having a control unit, a plurality of drawers, and connections to servers and databases. FIG. 24 shows the drug administration cabinet of FIG. 23, showing two input devices, one is a keyboard and the other is a pointing device in the form of a “mouse”. FIG. 3 is an exploded view of the drawer taken from the opening of the drug cabinet and the Faraday box, with a partition for creating a pocket for containing medical items, a TEC enclosure located at the back of the drawer, and a Faraday box generated in the cabinet. 3 shows details of a drawer design including a portion. FIG. 26 is an enlarged view of the drawer of FIG. 25 as viewed from the rear, looking at the metal front of the drawer that completes the Faraday box around the drawer so that the RFID system works effectively when the drawer is in the closed position. Can be taken. FIG. 26 is another view of the drawer of FIG. 25 showing the TEC device enclosure in the rear of the drawer in more detail, showing a thermal diffuser formed into the enclosure. FIG. 5 is a more detailed view of the configuration of the cabinet surrounding the drawer to be cooled, with a slab of insulation around the top, bottom and sides of the drawer, and a metal lining to form a Faraday box Is shown. FIG. 4 shows a view of a portion of the front of the drawer, showing the insertion of insulation into the front panel of the drawer. FIG. 4 shows a perspective view of a system according to an aspect of the invention, with a cooled drawer with TEC device attached (in the open state), a drug located in the drawer pocket, three temperature sensors located in the pocket, ambient temperature Fig. 3 shows connections to sensors, control units, and servers and databases. FIG. 4 illustrates a method according to an aspect of the present invention that results in an automated system that detects drugs to be temperature controlled, identifies the temperature requirements of those drugs, and controls the TEC device to maintain the required temperature; It also shows a temperature data tracking system to meet the requirements imposed by health authorities. An RFID detection system detects the presence of a temperature-controlled medical product and informs the processor, which identifies the temperature requirements of the detected drug and configures the drawer TEC device to maintain the required temperature. FIG. 2 is a block diagram of a system according to an aspect of the present invention in which a controlling and further processor is programmed to generate a log of temperature events while medication is in the cabinet.

  An RFID with a unique individual identification number will now be described in more detail with reference to the exemplary drawings to describe embodiments of the invention in which like reference numbers represent corresponding or similar elements in several drawings. A schematic diagram of a partial enclosure 20 in which a plurality of medical articles 22 each having a tag 24 is stored is shown in FIG. The partial enclosure may comprise a drawer having a front face 26, a left side 28, a right side 30, a back face 32, and a bottom face 34. These articles are randomly distributed in the drawer with the RFID tag oriented in various random directions.

  As used for the embodiments herein, "reader" and "interrogator" refer to devices that can read or write / read. A data capture device is always referred to as a reader or interrogator, whether it can only read or write. A reader typically includes a radio frequency module (transmitter and receiver, sometimes referred to as a “transceiver”), a control unit, and a coupling element (such as one or more antennas) to an RFID tag. . In addition, many readers include an interface for transferring data to any location, such as an RS-232 interface. When transmitting, the reader has an interrogation zone in which the RFID tag is activated. Within the interrogation zone, an RFID tag generated in the interrogation zone by the reader draws power from the electric / magnetic field. In a continuous RFID system (SEQ), the interrogation hall is switched off at regular intervals. RFID tags are programmed to recognize these “off” gaps and are used by the tag to send data such as the tag's unique individual identification number. In some systems, tag data records are captured at the time of tag manufacture and include a unique serial number that cannot be changed. This number may be associated with the specific item in the database when the tag is attached to the specific item. Thus, by determining the location of the tag, the location of the article to which the tag is attached is determined. In other systems, the RFID tag may include more information about the item to which the tag is attached, such as the item name, item identification, expiration date, dose, patient name, and other information. The RFID tag may be writable so that it can be updated.

  As used for the embodiments herein, “tag” means referring to an RFID transponder. Such tags typically have a coupling element such as an antenna and an electronic microchip. Microchips contain data storage, also called memory.

  FIG. 2 represents a typical medical retrieval cabinet 40 with a plurality of movable drawers 42. In this embodiment, there are five drawers that slide outward from the cabinet to access the contents of the drawer. FIG. 1 is positioned in the cabinet of FIG. 2 to slide outward to give access to the contents of the drawer and to slide inward into the cabinet to securely store the contents of the drawer. 1 is a schematic drawing of a representative drawer that may be provided. The cabinet also includes an integrated computer 44 that may be used to control access to the drawers, generate access and content data, and communicate with other systems. In this embodiment, the computer provides data regarding the number and type of the item in the drawer, the name of the patient to whom the item was prescribed, the prescribed drug and the date and time of administration of the prescribed drug, and other information. Generate. In a simpler system, the computer simply receives a unique individual identification number from the stored item and sends these to an inventory management computer that has access to a database to match the individual identification number with the item description. Send individual identification number.

  Such a cabinet may be installed in a nurse station on a particular floor of a health care organization and may contain patient prescription drugs on that floor. When the patient's prescription drug on that floor is prepared, the prescription drug is carried and placed in the cabinet 40. The prescription drug may be recorded in the integrated computer 44 and the receipt of the prescription drug may be notified to the pharmacy. The withdrawal may include non-prescription medical supplies or articles for dispensing to the patient as determined by the nursing staff. At the appropriate time, the nurse uses the computer 44 to access the drawer where the medical items are stored and removes specific patient prescription drugs and any required non-prescription items and then strictly Close the drawer to be stored. In order to access the cabinet, the nurse may need to provide various information and may require a secure access code. The drawer 42 may be locked or unlocked depending on the required conditions.

  The computer 44 may be in communication with other facilities of the health care organization in some cases. For example, the computer 44 may notify the pharmacy of the health care organization that the patient's prescription medication has been removed from the cabinet for administration at a particular date and time. The computer may also notify the health department's finance department that prescription drugs and other medical items have been removed for administration to a particular patient. This medication cost may then be applied to the patient's bill. In addition, the computer 44 may communicate that it has been administered to update the patient's medication administration record (MAR), the so-called e-MAR. The computer 44 of the medication cabinet 40 may be wirelessly connected to other computers of the health care organization or may have a wired connection. Wheels may be attached to the cabinet, and the cabinet may be moved or stationary so that it cannot be moved as necessary.

  Systems that use RFID tags often employ an RFID reader that is in communication with one or more host computing systems that act as a repository for storing, processing, and sharing data collected by the RFID reader. Referring now to FIGS. 3 and 4, a system and method 50 for tracking an article is shown, in which the drawer 20 of the cabinet 40 of FIG. 2 is located on the article in the drawer. Monitored to obtain data from the RFID tag. As described above, a stable field of EM energy needs to be established in the storage area so that the RFID tags attached to various storage articles operate in any direction.

  3 and 4, a tracking system 50 for identifying items in an enclosure is shown and includes an EM energy transmitter 52 as part of an RFID reader. The transmitter 52 has a specific frequency, such as 915 MHz, to extract EM energy by the transmit antenna 54 and transmit it into the 20. The transmitter 52 is configured to transmit the required RFID EM energy and any required timing pulses and data into the enclosure 20 in which the RFID tag is located. In this case, the enclosure is a drawer 20. The computer 44 of the RFID reader 51 controls the EM transmitter 52 so as to repeat a transmission period and a non-transmission period, a so-called off period. During the transmission period, EM energy transmitted above the threshold intensity level activates the RFID tag by surrounding the RFID tag in the drawer. The transmitter 52 is then switched to the off period, during which the RFID tag responds to the respective stored data.

  The embodiment of FIG. 3 includes a single transmit probe antenna 54 and a single receive antenna 56 that is oriented to optimally read data transmitted by an operational RFID tag installed in the drawer 20. A single receive antenna 56 is communicatively coupled to the computer 44 of the reader 50 located on the outside of the drawer 20 or on the inside bottom of the drawer. Other mounting locations are possible. A coaxial cable 58 or other suitable single link can be used to couple the receive antenna 56 to the computer 44. In different embodiments, a wireless link may be used. Although not shown in the drawings, those skilled in the art will recognize that various additional circuits and devices are used to separate digital data from RF energy for use by a computer. Let's go. Such circuits and devices are not shown in FIGS. 3 and 4 so as not to unnecessarily complicate the drawings.

  The embodiment of FIG. 4 is similar to the embodiment of FIG. 3, but differs in that it uses two transmit probe antennas 60 and 62 and three receive antennas 64, 66 and 68. The configuration and number of transmit probe and receive antennas used in the system are at least the size of the enclosure 20, the operating frequency, the relationship between the operating frequency and the natural resonant frequency of the enclosure, and the expected number of RFID tags placed in the enclosure. Since it may vary based in part, all of the RFID tags in the enclosure can be reliably activated and read. The location and number of RFID reader components may depend on the particular application. For example, a smaller number of components may be required for a relatively small size enclosure, whereas more components may be required for more enclosures, as shown in FIG. Although shown in block form in FIGS. 3 and 4, it should be understood that each receive antenna 56, 64, 66 and 68 of system 50 may comprise a subarray in different embodiments.

  The transmit antennas (54, 60 and 62) and the receive antennas (56, 64, 66 and 68) may take different forms. As described in more detail below, in one embodiment, a plurality of “patches” or microstrip antennas are used as the receiving antenna of the reader and are located adjacent to various portions of the bottom of the drawer. On the other hand, the transmitting antenna is a wire probe installed at a position adjacent to the upper part of the drawer. Note that in the embodiment of FIGS. 3 and 4, the RFID reader 50 may be permanently attached to the same cabinet in an advantageous position relative to the drawer 20.

  One solution to reliably address RFID tags that are densely or randomly oriented in the enclosure is to treat the enclosure as a resonant cavity. Establishing resonance in the cavity enclosure provides a stable electromagnetic field that can actuate all RFID tags in the enclosure. This creates an enclosure from conductive walls, using one or more probes to excite the transverse electric field (TE) or transverse magnetic field (TM) in the cavity at the natural resonant frequency of the cavity, and is metallic This can be done by exciting the enclosure, the so-called cavity. This technique works if the cavity dimensions are specifically selectable to set resonance at the operating frequency, or if the operating frequency is selectable for a particular enclosure size. Since the frequency bands available for use in RFID applications are limited, changing the RFID frequency is not an option for many applications. Conversely, requiring physical dimensions for a specific set of enclosures such that the natural resonant frequency of the enclosure is equal to the available RFID tag operating frequency, for applications where the enclosure needs to be of a specific size Thus, the use of this technology is limited. This latter approach is not practical in terms of many different sizes, shapes and quantities of medical articles that need to be stored.

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. The enclosure may be embodied as a frame located around a non-metallic drawer in such a cabinet. Enclosure 80 is formed from the surfaces of metallic or metallized walls 82, floor 83 and ceiling 84, all of which are conductive. Wall 82, floor 83, and ceiling 84 may all be referred to herein as enclosure “walls”. FIG. 5 illustrates the use of energy coupling or probe 86 installed on top surface 84 of enclosure 80. In this embodiment, the probe 88 takes the form of a capacitor probe 88 in that it has a first portion 94 that extends axially through a hole 90 in the ceiling 84 of the enclosure. The purpose of the coupling is to efficiently transfer energy from the source 52 (see FIGS. 3 and 4) to the interior 96 of the enclosure 80. The probe size and position are chosen so that coupling is efficient, and the probe is placed in the region of maximum field strength. In FIG. 5, the TE ₀₁ mode is established using capacitive coupling. The length and distance of the bent portion 94 of the probe 88 affects the potential difference between the probe and the enclosure 80.

Similarly, FIG. 6 represents inductive coupling 110 of external energy to the enclosure 112. The coupling takes the form of a loop probe 114 attached through the side wall 116 of the enclosure. The purpose of this probe is to establish a TM ₀₁ mode in the enclosure.

Each of rectangular enclosures 80 and 112 shown in FIGS. 5 and 6, shown in Figure 7, and is shown in the abscissa 118 of graph by _{f n,} it has a natural resonant frequency _{f n.} This is the frequency at which the coupling power in the enclosure is maximum, as shown on the ordinate axis 119 of the graph. If the energy injected into the enclosure does not match the _fn frequency, the coupled power will not benefit from the enclosure resonance phenomenon. If the operating frequency cannot be changed and is other than f _n and the enclosure size cannot be changed to obtain f _n equal to the operating frequency, another power coupling apparatus and method must be used. In accordance with aspects of the present invention, an apparatus and method are provided for causing a forced resonance _ff to occur in an enclosure to obtain a standing wave in the enclosure using constructive interference. Such standing waves establish a stable energy field within the enclosure that is strong enough to operate all RFID tags within the enclosure.

When an EM wave that resonates with the enclosure enters, the EM wave bounces back and forth within the enclosure with low loss. As more wave energy enters the enclosure, it combines with the standing wave, strengthening the standing wave and increasing its strength (constructive interference). Since the cavity dimensions are integer multiples of the wavelength at the resonant frequency, resonance occurs at a particular frequency. In such cases where the injected energy is not at the enclosure's natural resonant frequency f _n , a solution according to aspects of the present invention is to set a “forced resonance” in the enclosure. This forced resonance differs from the enclosure's natural resonance in that the physical dimensions of the enclosure, like the resonant cavity, are not equal to an integer multiple of the wavelength of the excitation energy. Forced resonance can be achieved by determining the probe position along with the probe length that allows energy to be injected into the cavity such that constructive interference results and a standing wave is established. In this case, the energy injected into the enclosure sets an oscillation field region in the cavity, but is different from a standing wave present at the natural resonance frequency f _n of the resonance cavity. The EM field excited from this forced resonance is different from the field structure seen in the natural resonance of the resonant cavity, but still with the proper probe placement of the probe, a stable EM field is used to call the RFID tag Can be established. Such a state is illustrated in FIG. 8, in which it is noted that the curve of the coupled power of the forced resonance f _f is close to that of the natural resonance f _n .

Referring 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 according to FIG. 5 to establish the TE ₀₁ mode. The second probe 114 is inductively coupled to the enclosure 120 in accordance with FIG. 6 to establish the TM ₀₁ mode. Both of these two probes are coupled to the enclosure to inject energy at a frequency f _f other than the enclosure's natural resonant frequency f _n . Positioning these probes against the ceiling 126 and wall 128 of the enclosure optimally couples energy into the enclosure and establishes a stable EM field in the enclosure for reading RFID tags that can be installed in the enclosure. A forced resonance is obtained in the enclosure 120. According to an aspect of the present invention, placing these probes against the wall of the enclosure, forced resonance curve f _f shown in FIG. 8 is obtained.

  Referring briefly to FIG. 10, an impedance matching circuit 121 that functions to match the impedance of the energy source 122 to the enclosure 120 is shown. The impedance matching circuit is installed between a coaxial cable 122 that supplies operating energy to the enclosure 120 and a capacitively coupled probe 88 that passes through a hole in the enclosure's metallic ceiling 126. Although no holes are shown in the view of FIG. 10, an insulator 123 is shown that electrically insulates the probe from the metallic ceiling. In this case, the matching circuit 121 consists only of a resistive attenuator 124 that is used by the enclosure 120 to reduce energy reflection. However, as those skilled in the art will appreciate, capacitive and inductive components tend to be in the enclosure and coupling 88. On the other hand, FIG. 11 represents an impedance matching circuit 124 having a passive reactive component for use in matching the impedance of the coaxial cable / energy source 122 and the enclosure 120. In this exemplary impedance matching circuit 124, the inductive component 125 and the capacitive component 127 are connected in series, but other configurations are possible including the addition of resistive components and other connection configurations.

  Passive components such as resistors, inductors and capacitors illustrated in FIGS. 10 and 11 can be used to form a matching circuit to match the impedance of the energy source and the enclosure. This helps the combined power in the enclosure. However, passive matching circuitry enhances impedance matching to the load of a particular enclosure, such as an empty enclosure, a partially loaded enclosure, or a fully loaded enclosure. However, because the contents of the enclosure are variable, impedance matching may not be optimized due to variations in the contents of the enclosure, changing the impedance characteristics of the enclosure.

  Such impedance matching de-optimization caused by enclosure load variations can be eliminated by using an active impedance matching circuit that 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 includes one or more fixed value passive components, such as inductors 132, capacitors 134, or resistors (not shown). In addition, one or more variable reactance devices, such as tuning capacitor 134, are incorporated into the circuit, which makes the circuit an active impedance matching circuit. The tuning capacitor 134 may be in the form of a varactor diode, a switched capacitor assembly, a MEMS capacitor, or a BST (Barium Strontium Titanate) capacitor. A tuning voltage is applied to the tuning capacitor 134 and is changed to change the capacitance provided by the device. Tuning capacitor 134 provides the ability to actively change the impedance match between probe 140 and enclosure 142.

  To complete the active matching circuit, a bi-directional coupler 144 can be incorporated with two power sensors 146. Bidirectional coupler 144 and power sensor 146 provide the ability to sense forward and reflected power between RFID transceiver 148, active matching circuit 130, and enclosure 142. Continuous monitoring of the ratio of forward power to reflected power by the comparator 150 provides a metric that can be used to adjust the tuning capacitor 134 to keep the probe 140 impedance matched to the enclosure 142. The ability to continuously monitor and enhance impedance matching as the enclosure contents change is provided using the active matching circuit 130.

Referring now to the side cross-sectional view of FIG. 13, there are two ceiling mounted 160 probe antennas 162 and 164 mounted in an enclosure, also referred to herein as a cavity 166, which operate as a Faraday box in this embodiment. It is shown. As shown, the Faraday box 166 includes a wall 168 (one of a plurality of walls is shown) 168, a back surface 170, a floor 172, a ceiling 160, and a front surface 161 (only the position of the front wall is shown). With. All surfaces forming the cavity are electrically conductive and electrically connected to each other and are structurally formed so as to be able to conduct the energy frequency f _f injected by the two probes 162 and 164. In this embodiment, the cavity 166 is constructed as a metal frame 167 that may form part of a medical supply cabinet similar to that shown in FIG. A slidable drawer may be mounted in the metal frame. The slidable drawer in this embodiment is formed from an electrically inert material, i.e. is not conductive except at the front. When the drawer slides into the cabinet into the closed configuration, the drawer's conductive front panel is placed in electrical contact with one or more other parts of the metal frame 167 so that the Faraday box 167 is in contact with the drawer. A front wall 161 is formed.

  The amount of insertion or retention of each probe into the cavity by the central conductor 180 is selected to achieve optimal coupling. The length of the probe bend 94 is selected to provide good impedance matching. The position of the probe relative to the cavity wall is selected to produce a standing wave in the cavity. In this embodiment, the probe antennas 162 and 164 are installed at specific distances D1 and D3 from the front wall 161 and the back wall 170, respectively. According to one aspect of the present invention, these probe antennas are only activated continuously after the other probe is deactivated. It has been found that this configuration provides a standing wave when the injected energy wave is in phase so that constructive interference is obtained as a result.

  FIG. 14 is a front perspective view of the probe configuration of FIG. 13 again showing two probe antennas 162 and 164 installed in a Faraday type enclosure 166 to establish a stable EM field for the inserted article storage drawer. It is. Note again that the Faraday cavity 166 is assembled as a metallic frame 167. In the figure, the cavity is incomplete in that there is no front of the “box”. In one embodiment, this front face is provided by a slidable drawer conductive front panel. When the drawer is slid into the cabinet, the rest of the drawer other than the front panel is plastic, or if it is not plastic, it is non-conductive, but the front panel is in addition to the metal frame 167. The Faraday box 166 is completed by being in electrical contact with the portion. In the embodiment described and illustrated herein, the two probe antennas 162 and 164 are both installed along the centerline between the side walls 166 and 168 of the frame 166. The enclosure is, in one embodiment, 19.2 inches wide, and the probe antennas are spaced 9.6 inches from each side wall. Such a centered location between the two sidewalls is for convenience in one embodiment. The probe may be located anywhere in other embodiments. In this embodiment, the spacing of the probes 162 and 164 from each other is of little importance because they are actuated continuously. Although not shown, two receive antennas are also placed in the Faraday box 166 to receive response signals from the activated RFID tag in the cavity 166.

  It should be noted from the drawing reference that each probe has a bend used to capacitively couple to the ceiling 160 of the cavity, as shown in FIG. The front side probe 162 is bent forward while the back side probe 164 is bent backward. The purpose of this configuration is to obtain more spatial diversity and better reach due to the EM field established in the drawer. Other arrangements are possible to achieve a stable field in the cavity 166. In addition, two probes are used for a particular enclosure 166 to provide good EM field reach of the enclosure 166.

FIG. 15 is a cutaway side perspective view of the dual probe antennas 162 and 164 of FIGS. 13 and 14, with the drawer removed for clarity. As shown in the figure, the front probe 162 is spaced from the left wall by ½λ of the operating frequency F _f . Note that each probe has a bend that is used to capacitively couple to the ceiling 160 of the enclosure 166, as shown in FIG. In order to obtain more spatial diversity and better reach by the EM field of the drawer, the front probe 162 is bent forward to couple with the front part of the enclosure, whereas the rear probe 164 is bent rearward to couple with a more rear portion of enclosure 166. Other arrangements are possible to achieve a stable field within the enclosure as well as additional spatial diversity and reach.

  FIG. 16 is a front upward perspective view of the frame 167 forming a Faraday box 166 showing the portion of the drawer 180 slidably mounted within the frame 167. The drawer's metallic front panel has been removed so that the sliding motion can be seen more clearly. Note that the dual ceiling mounted probe antennas 162 and 164 are covered and protected by an electromagnetically inert protective cover 182. The drawer is formed of a non-metallic material such as plastic or other electromagnetically inert material having a low RF constant. The drawer back 184 is cut away so that a cooling system 189 with a coil 186 and a fan 188 installed on the back of the frame 167 can be seen. In this case, the drawer 180 is slidably attached to the frame of the Faraday box together with the metallic slide hardware 190. Because the drawer slide hardware is near the sides of the frame 167 of the enclosure 166 and may be in electrical contact with the metal slide hardware on the enclosure sidewall 168, these metal rails are located within the enclosure. It has a small impact on the EM field established in

  FIG. 17 is a front perspective view looking upward from an angle opposite to that of FIG. 16, but with the drawer removed. The frame 167 includes a mounting rail 192 for receiving the slide of the drawer 180 in this embodiment. In this embodiment, the mounting rail is made of a metallic material but is in electrical communication with the box because it is secured to the side 168 of the Faraday box. The figure also shows a spring mechanism 194 that is used to facilitate the outward sliding of the drawer so that the articles stored in the drawer can be accessed. The spring is configured to automatically push the drawer outward when the drawer latch is released.

FIG. 18 is a schematic diagram showing measured values of the arrangement of two TE ₀₁ mode capacitive coupling probes 162 and 164 on the ceiling 160 of the frame 167 shown in FIGS. In this embodiment, the operating frequency of the RFID tag is 915 MHz, so the wavelength is 0.32764 meters or 1.07494 feet. Thus, the half wavelength is 0.16382 meters or 6.4495 inches. The length of each capacitively coupled bend 200 of the probe is 5.08 cm or 2.00 inches. The length of the probe axial extension 202 into the enclosure is 3.81 cm or 1.50 inches when measured from the insulator 204 into the enclosure 166. The configuration and arrangement of the probe in this embodiment is based on an operating frequency of 915 MHz. In one embodiment, the depth of the enclosure 166 is 16.1 inches (40.89 cm), the width is 19.2 inches (48.77 cm), and the height is 3 inches (7.62 cm). . The optimal probe placement for this size and shape (rectangular) enclosure and 915 MHz operating frequency is 5.0 inches (12.7 cm) between the front probe and the front wall, and between the back probe and the back wall. The spacing was found to be 5.0 inches (12.7 cm). As mentioned above, in this embodiment, the probe is only activated continuously.

  FIG. 19 is located between two microstrip or “patch” antennas 210 and 212 and their respective antennas and, in one embodiment, the back of the enclosure to which the antenna is connected to an SMA connector (not shown). 17 is a schematic illustration of the size and placement of the microstrip conductors 214 and 216 within the enclosure 166 of FIG. Supply line 58 (FIG. 3) may be connected to these SMA connectors and routed to computer 44 for use in communicating RFID signals for further processing. Some spacing measurements for microstrip components are given in inches. The 9.7 inch spacing is equivalent to 24.64 cm. The width of the 0.67 inch microstrip line is equivalent to 17.0 mm. The 1.4 inch spacing is equivalent to 3.56 cm. Other configurations and types of receive antennas may be used with different numbers of such antennas. In this embodiment, the receiving antenna is attached to the insulation on the bottom inner surface of the metallic enclosure frame 167 so that the receiving patch antenna is not in contact with the metal surface of the Faraday box.

  Referring now to FIG. 20, the field strength or field strength in the enclosure described above is shown on the ordinate axis shown in volts / meter and the abscissa axis shown in meters. Maximum field strength occurs at a position of approximately 5.0 inches (0.127 m), where the probe position is 5.0 inches (12.7 cm) from the front wall and the operating frequency is 915 MHz. You can see from the figure that this is the result. Referring now to FIG. 21, a large increase in field strength is seen at 5.0 inches (12.7 cm), but the scale is reduced. It can be seen more clearly that the strength of the field decreases on the right side wall, but remains strong very close to the left side wall. Thus, in one embodiment, the use of a second probe located 5.0 inches (12.7 cm) from the right side wall provides a mirror image field strength as shown in FIG. The two probes 162 and 164 are operated sequentially and both are not operated simultaneously. A better EM field reach of the enclosure 166 is obtained using two probes, and the RFID tag of the article located near the front wall 161 is actuated by the front probe 162 and near the back wall 170. Note that the RFID tag of the positioned article is actuated by the backside probe 164 (see FIG. 13).

式中、Ｎ＝正の非ゼロ整数、例えば、１、２、３、など
Ｌ_１＝プローブと背壁との間の距離
Ｌ_２＝プローブと前壁との間の距離
λ_ｇ＝キャビティの波長 While not wishing to be bound by theory, the following equation may be useful in deriving the probe location in TE mode in a square or rectangular non-resonant cavity.

Where N = positive non-zero integer, eg 1, 2, 3, etc. L ₁ = distance between probe and back wall L ₂ = distance between probe and front wall λ _g = wavelength of cavity

L ₁ is not zero in the TE mode, meaning that there is no probe to excite the TE mode at the front or back wall position. For TM mode, the equation is the same, but N is equal to zero and other positive integers. The probe position is not λ _g / 2 from the front or back wall. L ₁ and L ₂ are selected such that N can be a positive integer that satisfies the equation. For example, in the case of the enclosure 166 described above,
L ₁ = 4.785 inches L ₂ = 11.225 inches λ _g = 12.83 inches

Therefore,

  In an actual enclosure, the probe is installed at a location (5.0 inches) that is slightly different from the value shown in the equation (4.785 inches), which may in some cases insert a plastic drawer into the cavity. This is because the phase from the reflected signal is changed. The above equation is set up so that the reflection phases from both the front and back walls are equal, i.e., "in phase" at the probe location.

The wavelength λ _g of the enclosure can be calculated using the waveguide equation. The equation for a rectangular cavity is shown below. This calculation requires a cut-off frequency. For cylindrical cavities or other shapes, the equation changes.

The cut-off frequency is that at which g disappears. Therefore, the cutoff frequency in hertz is as follows.

式中、ａ＝内部の幅
ｂ＝内部の高さ
ｍ＝「ａ」方向の場の１／２波長変動の数
ｎ＝「ｂ」方向の場の１／２波長変動の数
ε＝誘電率
μ＝透磁率 The cutoff wavelengths in meters are as follows:

Where: a = internal width b = internal height m = number of ½ wavelength fluctuations in field in “a” direction n = number of ½ wavelength fluctuations in field in “b” direction ε = dielectric constant μ = permeability

The mode with the lowest cut-off frequency is called the main mode. Since the TE ₁₀ mode is the smallest possible mode that gives the rectangular waveguide a non-zero field representation, it is the main mode of a> b rectangular waveguide where the main frequencies are:

Wave impedance is defined as the ratio of the transverse electric field and the transverse magnetic field. Therefore, the impedance is as follows.

式中、以下のようになっている。

The guide wavelength is defined as the distance between two in-phase planes along the waveguide and is equal to:

In the formula, it is as follows.

  FIG. 22 represents a block electrical signal diagram of a multiple drawer medical cabinet as shown in FIG. In this case, the cabinet has eight drawers 220. Each drawer includes two top antennas, two bottom antennas, and a lock with a lock sensor 222 to secure the drawer. Signals to and from each drawer antenna are supplied through the RF multiplexer switch 224. Each RF multiplexer switch 224 handles the routing of the RF signal in this embodiment for a two stage drawer. The RFID field and the received RFID signal are sent to the main RFID scanner 230 through the respective RF multiplexer switch 224. The output of the scanner 230 is in this case directed to the microprocessor 232 for use in communicating relevant information to a remote location via a wired connection 234 and a wireless connection 236. FIG. 20 also shows various support systems such as power connection, power distribution, backup battery, wiring PCBA, USB support, and cooling.

  According to one embodiment, the drawer is continuously monitored. Within each drawer, the antenna is operated continuously by an associated multiplexer 224. Other embodiments of the signal and electrical control system are possible.

  In this specification, RFID tags are used as an embodiment, but other data carriers that communicate by electromagnetic energy may also be usable.

Cooling Drawer Referring now to FIG. 25, a generally non-metallic sliding drawer 330 is configured to be attached to the drug cabinet 332. Various dividers or dividers 334 are provided in the drawer that form “pockets” 336 in which medical items are placed for storage and administration. The cabinet in which the drawer is slidably mounted includes a metal frame 338 that surrounds the drawer to function as a Faraday box. Referring now further to FIG. 26, the front 340 of the drawer 330 can be formed of metal 342, or the front 340 of the drawer 330 can be metal in the cabinet 332 when the drawer is in a closed state. It may include a metal portion that contacts the rest of the frame 338 to complete the Faraday box around the drawer. Within this frame, as described in more detail above, an RF system is provided for detecting the presence of an RFID tagged article in the drawer.

  Referring now to FIG. 16, in accordance with another aspect of the present invention, a thermoelectric cooling (“TEC”) device 189 is located at the rear of the metal frame 170. See also FIG. 30 showing the position of the TEC device 189 attached to the drawer and moving with the drawer to the open and closed positions. In one embodiment, the TEC device is placed in the rear corner of the drawer rather than in the middle. An RFID reader 182 for detecting an RFID-tagged article in the drawer 180 is provided in the frame around the drawer, with the probes 162, 164 being located in the center above the drawer in this embodiment. Thus, there is not much space available for the TEC device 189 in the center of the drawer. In addition, the inventors of the present invention have realized that the TEC device must actually protrude to some extent in the drawer because of the need to keep the drug cabinet and drawer smaller. It has been found that when the TEC device is located at the rear corner of the drawer, it only interferes with the two pockets 336 of the drawer as seen in FIG. However, if the TEC device is placed in the center of the drawer, it will interfere with the three pockets and the storage space for storing medical items in the drawer will be small.

  In one embodiment of the present invention, a Peltier TEC device 189 is used. Such units are available from TE Technology, Inc. of 1590 Keane, Travel City, MI. From part number AC-037 (www.tech.com). In this embodiment, Peltier units are used because of their small size, semiconductor properties, availability, and sufficient cooling capacity. The use of such a unit provides several significant advantages, one of which is that there is no vibration because no compressor is required. However, the present invention is not limited to heat-cooling units, and other units that may be available in the existing or future can be used.

  One advantage of the present invention is that the cabinet of this embodiment has both a cooled drawer and an uncooled drawer. In the prior art, as described in detail in the background section above, either the entire cabinet is either cooled or not entirely cooled. This is an undesirable technique because it requires two cabinets for two different types of drugs, one that always needs cooling and the other that needs to be at room temperature for use. is there. Accordingly, a cabinet that can provide both cooled and uncooled drawers is needed and provided herein in the art.

  Referring again to FIG. 25 and further to FIG. 27, the enclosure TEC device 350 is shown in the rear corner of the drawer 330. In FIG. 25, the enclosure 350 is covered, but FIG. 27 shows the enclosure more clearly. This enclosure is part of the “rear estate” of the drawer and is used to receive the TEC device when the drawer is in the closed position. It should be noted that holes 352 are formed in the enclosure 350 at the front and side partitions 334 that function to diffuse the cooling effect of the TEC device. Further, FIG. 16 shows that the TEC device 189 of this embodiment includes a fan 188 that reduces or eliminates the temperature gradient that tends to exist in the drawer 330 when combined with a diffuser (FIG. 25). The size and position of the partition 334 and the perforated holes 360 also help reduce the temperature gradient.

  In one embodiment, the TEC device 189 is secured to the frame of the cabinet 300 and the drawer 330 engages the TEC device 189 when closed and moves away from the TEC device 189 when opened. This configuration is shown in FIG. This allows ambient air to have a greater effect on the contents of the drawer when the drawer is in the open position. In another embodiment, as shown in FIG. 30, the TEC device is secured to the drawer 330 and moves with the drawer when the drawer is opened. This allows cooler air from the TEC device to be always present, thus reducing the effect of ambient air on the drawer contents when the drawer is opened.

  Turning again to the drawer 330, the RF drawer as intended by the present invention uses both electrical and thermal insulation. The electrical insulation forms the required Faraday box (as shown in FIG. 28, part of which is shown as frame 338 in FIG. 25 and shows the part of the cabinet with the drawer removed). As such, it is provided by placing conductive material on all sides around the drawer. Thermal insulation 344 is provided by using widely available standard insulation. In some cases where a large surface area is available, the insulation slab is cut to the appropriate size and placed in the frame around the location of the drawer 330 as shown in FIG. As shown in FIG. 29, the front portion 340 of the drawer 330 can also have a thermal insulation 344 therein. In areas such as the back of the drawer where electrical conductors and other equipment used in conjunction with the drawer are present, after the manufacture of the drawer has been completed, the spray is applied to place the required insulation around the drawer. A thermal insulation of the formula (not shown) can be used. The use of high quality insulation, such as semi-rigid PVC foam, not only keeps the cold air inside the drawer when the drawer is in the closed position, but is also created by the TEC device 189 for that particular drawer. Protect adjacent drawers from cooling. It can be seen that with the proper amount of insulation, the adjacent drawers can remain at room temperature and the cooled drawers can be kept in the range of 3-10 ° C.

  In one embodiment, the TE Technology Peltier thermoelectric cooler module 189 described above is used and has a capacity of 73 watts at a 0 ° temperature differential. A medicine cabinet 300 in which this cooler module is installed to cool one drawer 330 holds a total of five drawers. It has been found that by using a Peltier unit of this capability in conjunction with the ambient isolation technique described above and in the drawings, the subject drawer can be kept at the desired temperature and adjacent drawers can be kept at room temperature. . In addition, the power requirements and size of TEC devices are significantly reduced compared to systems based on traditional compressors.

  In another feature, the TEC device 189 of the drawer 330 of the cabinet 300 can be selectively turned off so that the cooling system does not operate and the drawer can be brought to ambient temperature. This allows the medical facility to reduce costs because the TEC device 189 does not waste power.

  In a further feature, the drawer 330 includes at least one temperature sensor 370. Temperature data from these sensors can be communicated to the control unit 306 for monitoring. In the unlikely event that the temperature of the drawer to be cooled rises above a predetermined threshold, an alarm can be provided on the display device 304. In addition, the control unit 306, server 310, and database 320 can cooperate to perform temperature data tracking records for historical charting and analysis. In the embodiment of FIG. 30, an ambient temperature sensor 372 is provided. The sensor is positioned away from the heat outlet of one or more TEC devices so that its reading is not affected by the exhaust heat of the TEC device. Having only one ambient temperature sensor eliminates the need for a sensor on each uncooled drawer. The drawers are presumed to be at ambient temperature because they do not have a temperature control device acting on them.

  The present invention utilizes a database 320 that can be maintained by a medical institution to list medications and other medical supplies that require refrigeration. In addition, there are RFID systems that determine the need for refrigerated drug environments in RFID-enabled take-out cabinets 300 or mobile carts 318 and control such environments. The system automatically determines what conditions are required for the drug placed there by the database, maintains the environment required by the drug, and at a predetermined time interval for the purpose of recording history. Make necessary inputs / outputs to ensure they are recorded on the basis.

  When the medication 378 is placed in the RFID retrieval cabinet 300 or the movable cart 316, the system recognizes the need for cooling, if necessary. This recognition can be done in various ways. In one method, an RFID tag associated with a drug can be encoded to indicate that temperature control is required and how much temperature control is required. In another method, the control unit 306 is withdrawn from the RFID detection system, receives 330 medication identifications, accesses the remote server 310 and its database 320, and provides data on the identified medication (temperature control Indicates need and temperature required).

  A “smart” system via the host computer 306 produces the necessary output to determine the need for cooling and provide the correct environmental conditions for it. More particularly, turning to FIGS. 30 and 31, systems and methods for this “smart” system are shown. In FIG. 30, the cabinet 300 is shown with the drawer 330 open. Drawer pockets are shown, some of these pockets containing medication 378, each medication having an RFID tag. When the drawer is pushed back into the cabinet, the RFID system automatically detects and reads the drug tag (step 400). In one embodiment, the control unit 306 receives data from the RFID tag and automatically contacts the remote server 310 to look up the drug in the database 320 (step 402). The control unit then determines whether the drug requires temperature control (step 404). If temperature control is required, the control unit automatically measures the ambient air temperature by referring to the ambient temperature sensor 372 (step 406) to determine whether a cooled drawer is required. (Step 408). If the temperature of the cycle air meets the requirements of temperature controlled medication 378, the control unit continues to monitor ambient temperature to ensure that no change has occurred.

  In another embodiment, an RFID tag located on each medication 378 includes a temperature sensor, and a portion of the data transmitted by the medication RFID tag includes the temperature of the medication.

  If the ambient temperature does not meet the drug temperature requirement, the control unit determines whether the temperature of the drawer where the drug is placed can be controlled (step 410). If this is not possible, an alarm is automatically provided that the drug must be moved to a cooled drawer (step 412). Once the medication is transferred to the cooled drawer, the RFID system automatically determines again the presence of the medication in that drawer, and then the control unit 306 sets the temperature of the TEC device (step 414) and Keep together.

  Another feature in accordance with aspects of the invention is that temperature monitoring and tracking is performed. The control unit 306 determines whether a temperature controlled (TC) drug is placed in the drawer (step 420). If so, the drawer's temperature sensor 370 is monitored by the control unit 306 (step 422) and periodically recorded as required by the medical institution or other authority's policy (step 424). If necessary, the record can be printed or transferred to another location in digital form.

  Turning now to FIG. 32, a block diagram of a system 440 according to aspects of the present invention is shown. An RFID detection system 442 located in the cabinet drawer detects the presence of a medical product having an RFID tag. The detection system 442 supplies data read from the RFID tag to the processor 444. The processor then accesses the server 446 and associated database 448 to characterize the detected medical product and determine whether the medication has a need for temperature control. Other data about the medical item may be important for tracking this item or for other purposes.

  If the medical product requires temperature control, the processor accesses the ambient temperature sensor 450 to determine whether the ambient temperature meets the requirements of the medical product. If the medical product requires a temperature below ambient temperature, the processor determines whether the medical product is currently located in a temperature controlled drawer of the medication cabinet. If not, the processor displays a warning message on the display device 452 to cause the user to move the medical item to a temperature controlled drawer. Once this movement has occurred, the RFID detection system 442 automatically detects the presence of the medical item in the temperature controlled drawer and notifies the processor 444. The processor then sets the drawer's TEC device 454 to the correct temperature to be maintained. The TEC device automatically maintains the temperature of the drawer at the temperature required for the medical product. The system 440 of FIG. 32 can have one or more additional temperature controlled drawers that include a sensor 460 and a TEC device 462.

  The same applies to withdrawal from temperature controlled drug withdrawal. A processor monitors all medications that are withdrawn into and withdrawn and automatically controls the cooling device accordingly. If there is no longer any drug in the drawer that needs temperature control, the processor will automatically shut down the drawer's cooling unit, allowing the drawer to return to ambient temperature, thus wasting energy. Absent.

  In another feature, the processor monitors the drawer's temperature sensor 456 and logs 470 regarding the temperature of the medical product and the detected retention of the medical product, for example, as needed, such as twice daily. Is generated. The log can be kept in the processor's memory, transferred to a server, or otherwise stored or printed. The log can optionally include various details such as cabinet identification, drawer identification, temperature sensor type, calibration date, arrival date and time, retrieval date and time, and other data.

  Thus, RFID-enabled drawer refrigeration systems provide a number of advantages. Other drawers can cool at room temperature while specific drawers can be selectively cooled. Because of this feature, there is only one cabinet for both refrigerated medical items and room temperature medical items. Modular designs exist in that the drawer can be set and selected between cooling and ambient temperature.

  Throughout the specification and the following claims, unless otherwise required by context, the term “comprise” and variations thereof, eg, “comprises” and “comprising”, are open and inclusive meanings. In the sense of “including but not limited to”.

  Although the present invention has been described using what is presently considered to be the most practical and preferred embodiments, the present invention is not limited to the disclosed embodiments and elements, on the contrary. It should be understood that various modifications, combinations of features, equivalent arrangements and equivalent elements are intended to be included within the spirit and scope of the appended claims.

Claims (4)

A method of storing medical products,
Store medical items in a plurality of drawers in a medical cabinet, each configured to be withdrawn into and out of each cavity into a closed position within the cavity and an open position where the drawer is at least partially out of the cavity. Steps,
Attaching a thermoelectric cooling (“TEC”) device to provide cooling only to a first drawer located within the first cavity;
By isolating the first cavity from a second cavity located adjacent to the first cavity, cooling provided to the first drawer in the first cavity is provided to the second cavity. And preventing the second drawer from being reached and attempting to keep said second cavity and drawer at ambient temperature;
Detecting the temperature in the first drawer and recording a temperature reading over time;
Reading RFID tag data from an RFID tag located on an item located in the first drawer and determining whether a temperature requirement exists for the item to which the tag is attached;
Controlling the temperature in the first drawer by the TEC device to meet the temperature requirement when it is determined that an item in the first drawer has a temperature requirement;
Reading RFID tag data from an RFID tag located on an item located in the second drawer and determining whether a temperature requirement exists for the item to which the tag is attached;
Providing a warning that an item subject to temperature control has been placed in the second drawer if it is determined that a temperature requirement exists for the item in the second drawer. When the ambient temperature around the medicine cabinet is detected and ambient temperature data is provided to indicate it, as determined from the RFID tag data, if the medical product present in the first drawer requires a special temperature Is
The detected ambient temperature data is compared with the temperature required for the medical product, and if the ambient temperature satisfies the temperature required for the medical product,
Control the TEC device to the off state,
The method of claim 2. A cabinet for storing medical products,
  A plurality of drawers in the medical cabinet each configured to be inserted into and exited from the respective cavity into a closed position within the cavity and an open position at least partially out of the cavity;
  A thermoelectric cooling (“TEC”) device mounted to provide cooling only to a first drawer located within the first cavity;
  By isolating the first cavity from a second cavity located adjacent to the first cavity, cooling provided to the first drawer in the first cavity is provided to the second cavity. And insulating means to prevent reaching the second drawer and to keep the second cavity and drawer at ambient temperature;
  A recording device for detecting the temperature in the first drawer and recording the temperature reading over a long period of time;
  A read decision device that reads RFID tag data from an RFID tag located on an item located within the first drawer and determines whether a temperature requirement exists for the item to which the tag is attached;
  A control device that controls the temperature in the first drawer by the TEC device to meet the temperature requirement when it is determined that an item in the first drawer has a temperature requirement;
  A read decision device that reads RFID tag data from an RFID tag located on an item located in the second drawer and determines whether a temperature requirement exists for the item to which the tag is attached;
  A warning device for providing a warning that an item to be temperature controlled has been placed in the second drawer when it is determined that a temperature requirement exists for the item in the second drawer;
Including cabinet. When the ambient temperature around the medicine cabinet is detected and ambient temperature data is provided to indicate it, as determined from the RFID tag data, if the medical product present in the first drawer requires a special temperature Is
The detected ambient temperature data is compared with the temperature required for the medical product, and if the ambient temperature satisfies the temperature required for the medical product,
Control the TEC device to the off state,
Comprising a control device,
The cabinet according to claim 3 .

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