Refrigerated cabinet, especially for the cold chain of pharmaceuticals

Description of the invention

The subject of the invention is a refrigerated cabinet for the cold chain circulation of drugs, intended for storing and dispensing thermolabile drugs in hospital or outpatient conditions, with computer monitoring of the location and condition of these drugs and maintaining the required storage temperature.

Thermolabile drugs are delivered by wholesalers in appropriate refrigerators. A printout is made from the delivery confirming the storage and transport of such a product. Hospitals, which are a further link in the drug circulation chain, are usually unable to provide an appropriate method of thermal control of their storage. The idea of ​​controlling the cold supply chain in the factory and wholesaler and during transport may therefore end after the drugs have been delivered to the hospital. For this reason, it is necessary to build a system for storing and circulating medicines in the hospital that will allow for controlling their storage temperature until they are administered to the patient.

From the description US2006260335 there is known a solution concerning a refrigerator intended for home use, powered by a battery, which is equipped with a power supply system for both alternating current and direct current. This solution is intended for automatic or manual switching of the refrigerator to the DC power supply mode from the battery via an inverter, in the event of a failure in the home alternating current power supply. The controller of such a refrigerator is connected to a number of electrical components and is programmed to activate or deactivate these components in selected groups, more or less important, in order to reduce the level of electrical consumption while maintaining the temperature in at least one compartment below a predetermined safe maximum temperature. Each cooling compartment contains various shelves, wire shelves and containers for food products.

The controller is therefore designed to operate in two modes. In the first mode, all electrical components are started. In the second mode, the first set of components selected from the group is started, and the second set of components is turned off. It is also possible to turn off all components, leaving only the refrigeration system running. Alternatively, it is possible to switch off all components in the event of a power failure and restart the refrigeration system when the temperature measured by the sensors rises above a certain temperature.

US 7 775 056 describes an intelligent refrigeration system for storing containers of pharmaceutical products, such as vials, ampoules, syringes, bottles, drug tubes, blisters and cartons - at the point of dispensing. Embodiments of the invention utilize product identification technology, such as Radio-Frequency Identification (RFID) tags and readers, to uniquely identify containers as they are added to or removed from the refrigeration compartment of a refrigerator, and information about them is automatically retrieved from a local or remote database and includes various details related to the containers and their contents, such as manufacturing data, expiration dates, refrigeration time, inventory levels, safety information, usage statistics, known contraindications and warnings, etc. If the details indicate that there is a problem with a particular drug (e.g., that it is counterfeit, expired, suspicious, spoiled, recalled or almost out of stock), then a message or warning is automatically delivered to the operator via a connected output device such as a display screen, speaker or printer. Embodiments of the invention may also be configured to monitor and report temperature errors, power failures, and other anomalies related to the refrigerator or cold room.

US 8,749,356 describes an automated system and related method for storing medical supplies comprising a medicine cabinet having at least one refrigerated drawer having a thermoelectric cooling device and an unrefrigerated drawer. The design of the refrigerated drawer is such that cooling gradients across the drawer are minimized. Faraday cages are located around each drawer, which support separate RFID identification readers to monitor medical items in each drawer. Automatic RFID data detection system determines the temperature requirements of medical items in the refrigerated drawer and controls the cooling unit to maintain the required temperature. Temperature recording system for the refrigerated drawer is available. A separate RFID reader determines if a temperature-controlled item has been placed in an uncooled drawer and, if so, sends an alert.

There are basically two temperature ranges for storing drugs: 2 to 8 degrees C and 8 to 15 degrees C. This further complicates the monitoring process, as not only must the storage of drugs at reduced temperatures be monitored, but it is also necessary to distinguish precisely which drugs can be stored in one of the temperature ranges. Lack of full temperature monitoring can lead to the administration of drugs that have lost their therapeutic properties because they were stored outside of refrigerators for some time. Drug manufacturers, when providing a guarantee for the drug's effectiveness, specify the temperature conditions for storing the drug. Above or below the assumed values, drugs lose their properties, and what's more, they can even have the opposite effect to the intended one. That is why temperature monitoring is so important.

The situation of loss of value of a medicine may occur despite monitoring the refrigerators with medicines themselves, because there is no guarantee that the medicines are stored in the refrigerators. They may as well be stored in ordinary storage areas (25 degrees C). Moreover, there is no possibility of analyzing the circulation of medicines between refrigerators, e.g. during transport from the central warehouse to departmental warehouses. This means that it is advisable to improve the currently used processes and redesign them in such a way that the correctness of drug storage control is determined by a process that is independent of humans and recorded automatically.

There is therefore a need to create a solution that provides complete control over the place and time of storage of thermolabile drugs in the hospital, so that it can be determined on this basis whether the drugs are suitable for use. It should be emphasized that the solution largely concerns the monitoring of oncological drugs and will determine the effectiveness of therapy. A comprehensive system for storing and monitoring storage conditions will close the cold chain of drug circulation in the hospital from the moment of delivery to the hospital until the drug is administered to the patient.

The technical problem to be solved is the need to introduce refrigeration equipment for storing drugs, which will include solutions that improve storage conditions (in particular constant temperature and low humidity), with the possibility of selecting the appropriate temperature range, as well as monitoring the storage conditions of each individual drug package.

The refrigerating cabinet according to the invention comprises separate chambers located in a housing equipped with a cooling system with a compressor, a condenser and an evaporator.

The essence of the solution according to the invention is that the cabinet has two separate cooling chambers, one of which is intended for storing medicines at a temperature of 2 to 8 degrees C, while the other - at a temperature of 8 to 15 degrees C, separated by a material with low thermal transmittance in the form of a partition equipped with an EMC screen, and each of the cooling chambers constitutes a separate Faraday cage and is equipped with a separate transparent door, and the glass pane of each door is integrated with a screening mesh constituting an EMC screen.

Two separate cooling chambers with transparent separate doors have one common cooling system, equipped with two independent emergency temperature maintenance systems in the event of a device failure or power outage, the first level of protection is a built-in power supply with a battery, the second level of protection is a built-in cold accumulation buffer, connected to the evaporator of the cooling system and made of phase change materials with a phase change at the level of the expected temperature range from -8 to -6°C.

The screening mesh is made of steel wire having a diameter of 0.5 to 1.0 mm, preferably 0.8 mm, with a mesh opening size of 12.5 mm to 13.0 mm, preferably 12.7 mm, and the mesh is galvanically connected to the aluminum frame of the transparent door and through it to the device housing.

Inside each cooling chamber there is a separate RFID signal reading antenna connected to the control system.

The refrigerated cabinet is adapted to be connected to an IT system integrating devices used to monitor the circulation of drugs in the cold chain.

The advantage of the solution according to the invention is the introduction of appropriate temperature conditions, necessary for storing thermolabile drugs, for which temperature is a factor causing the loss of medicinal properties or even the possibility of harm to the patient. Creating two zones in the cabinets with different temperatures makes it easier for the service to choose the appropriate temperature range. The introduction of two independent emergency temperature maintenance systems ensures safe storage of medicines during failure removal.

In addition, it is possible to maintain low temperatures while keeping humidity as low as possible; a requirement entirely different from typical refrigeration where humidity is desired as a factor to enhance freshness.

The solution according to the invention is presented in an example embodiment in the drawings, the individual figures of which represent:

fig. 1 - refrigerating cabinet in a perspective view, with two separate chambers shown, fig. 2 - refrigerating cabinet in a front view, without doors, with shelves shown, fig. 3 - refrigerating cabinet in a longitudinal cross-section, fig. 4 - refrigerating cabinet in an exploded view, fig. 5 - the refrigeration system of the cabinet in an exploded view, fig. 6 - chamber door in a perspective view, fig. 7 - chamber door in a front view, with the screening mesh shown, fig. 8 - side view of the chamber door, Fig. 9 - perspective view of the screening mesh, Fig. 10 - RFID system diagram, Fig. 11 - diagram of the cabinet opening and locking system.

The refrigeration cabinet according to the invention in the housing 1 contains two separate refrigeration chambers 2, separated by a material with low thermal transmittance. One of the chambers is intended for storing medicines at a temperature of 2 to 8 degrees C, while the other - at a temperature of 8 to 15 degrees C.

For both chambers 2 with different temperatures, one cooling system is used. Air circulation in the individual chambers 2 as well as between the upper and lower chambers is forced by upper fans 3 and a middle fan 4, controlled by a thermostat. In each of the chambers 2 there are drawers 5 intended for storing medicines.

In the refrigeration system, the cabinet is equipped with a compressor 6 connected to a condenser 7 and an evaporator 8. During operation of the refrigerating cabinet, water vapour contained in the air of the closed refrigeration chamber 2 condenses on the lamellas of the evaporator 8. The condensed water vapour is discharged outside the device, which reduces the humidity inside the refrigerating cabinet.

The refrigerated cabinet is equipped with two independent emergency systems to maintain the temperature in the event of a device failure or power failure.

The first level of protection is a power supply unit (UPS) built into the cabinet (Uninterruptible Power Supply) with a battery (10) that allows for correct operation of the device for at least 30 minutes after a power failure.

The second level of protection (passive protection) is a cold accumulation buffer 11 built into the rear wall of the device, connected to the evaporator 8 of the cooling system via a capillary 12.

The cold accumulator buffer 11, the so-called cold accumulator, is made of phase change materials with a phase change at a temperature level of -8 to -6°C. During the operation of the device, the phase change material accumulates cold, which is later released to the device in the event of a failure of the mechanical cooling systems, allowing for an extension of the period of maintaining a low internal temperature in it.

The use of double security guarantees the safety of medicines by maintaining appropriate temperature conditions inside the cooling chambers.

Each of the chambers 2 is equipped with a separate transparent door 13 made in the refrigeration door technology using a double-glazed system with a low thermal transmittance coefficient mounted in a frame 14 made of a multi-chamber aluminium profile with an integrated refrigeration seal.

The external glass pane 15 of door 13 is integrated with a steel screening mesh 16. The parameters of the mesh 16 have been selected so that the signals emitted from inside the cooling chamber (signals from the antenna reading the electronic drug tags) do not spread to the outside and also so that external electromagnetic signals/interference do not interfere with the correct operation of the drug reading system.

A mesh made of steel wire with a diameter of 0.5 to 1.0 mm, preferably 0.8 mm, with a mesh opening of 12.5 to 13.0 mm, preferably 12.7 mm, is used. The mesh 16 is galvanically connected to the aluminum frame 14 and through it to the housing 1 of the device.

Two separate transparent doors 13 equipped with an internal screening mesh 16 in each wing, constituting an EMC (ElectroMagnetic Compatibility) screen, and an inter-chamber screening partition 21, made of a material with low thermal transmittance and also provided with an EMC screen, together with the remaining walls of the cabinet - define two separate Faraday cages, which are separately both chambers 2.

Faraday cages, by blocking the emission of electromagnetic radiation, enable the correct operation of the drug reading system, eliminating the possibility of reading drug markers located outside the chamber as well as external electromagnetic field interference that could affect such reading of markers inside the chambers.

The use of a screening mesh 16 integrated in the glass pane 15 of the door 13, instead of the standard screening provided by a solid steel door, allows the user to view the contents of the refrigerated cabinet without having to open it each time.

Inside the cooling cabinet there are two antennas 17 of the RFID system, one for each chamber, connected to the control system 18. In order to correctly read the drug data, high-power directional antennas are selected. The structure and power of the antennas allow for reading electronic tags connected to drugs regardless of their location inside a given chamber 2.

The use of independent shielding of chambers 2 with respect to electromagnetic radiation eliminates the possibility of erroneous reading of signals via antennas 17.

The cabinet is closed and opened using locks 19. The temperature setting controls, separately for each chamber 2, are located in the control panel 20.

The refrigerated cabinet according to the invention is intended for use in the cold chain of drug circulation in hospitals. Drugs are received from the supplier in the hospital pharmacy reception lock. Then, each drug package is indexed with an internal code - a unique number in the system, which is done in two ways, both by using the RFID radio code and the internal EAN barcode. The marked medicine package is then moved via a mobile cooling unit to a refrigerated cabinet where it is stored in the required temperature and humidity conditions.

At the same time, a file is created in the IT system, to which further data from the chain of drug circulation in the entire hospital can be added. This allows for full identification of a single drug package and monitoring of its movement within the hospital, until the drug is administered to the patient.

The cooling cabinet is connected to an IT system integrating all devices used in the system and monitoring the above-described circulation of medicines in the hospital. The system continuously records the temperature in the chambers of the cabinet or multiple cabinets, the time of placing and removing the medicine package from the cabinet, the time and amount of the medicine administered, changes in the state of the medicine in a single package - the amount of medicine in individual packages.

The system also provides solutions to prevent mistakes - alerts to prevent the accidental introduction of drugs into the wrong chambers of the cabinet, which is important due to the different temperature ranges in which drugs can be stored, alarm signaling of a temperature increase, alarm signaling of exceeding the storage time of the drug outside the devices (mobile refrigeration device for transporting drugs, refrigeration cabinet), and control of staff access to each drug package.