Patent Application
20240102716
This invention relates to a cold storage device, particularly for storage and/or transportation of vaccines and/or medical products and to methods of operating such devices.
To ensure their quality, longevity and effectiveness, vaccines must be stored and transported at an optimum storage temperature, generally ≥+2° C. and ≤+8° C. Exposure to higher or lower temperatures causes deterioration of the vaccines. Specialised vaccine storage refrigerators address these and other practical requirement, for example the avoidance of any significant temperature variation between different positions within a vaccine storage chamber. Some vaccine refrigerators, particularly sophisticated mains powered vaccine refrigerators used in health centres, also include data loggers for monitoring the temperature of stored vaccines over time; this facilitates verification that the vaccines have been maintained at appropriate cold chain conditions during the entirety of their storage. Alternatively, stand-alone data loggers, often having integrated temperature monitors, can be placed in a vaccine storage compartment along with vaccines being stored. The temperature histories recorded by such data loggers are generally transferred to separate computer monitoring systems for verification and display.
Particular issues occur for refrigerated vaccine storage where a reliable source of mains electricity is not available. For example, at remote health centres in developing countries which are not connected to the electricity grid, solar power systems are used to power ice-lined vaccine refrigerators. Such solar powered ice-lined vaccine refrigerators are configured such that their electrical cooling circuits generate an ice lining which acts as a thermal capacitor; the ice lining absorbs heat from its surroundings and contributes to maintaining the vaccine storage chamber within the desired temperature range when solar power is not available to power the electrical cooling circuit, for example at night or at periods during the day when insufficient solar radiation is available. Such solar powered ice-lined vaccine refrigerators have also been provided with temperature data loggers powered by a data system battery which is recharged when solar power is available. Another specific situation in the cold chain is, for example, where outreach vaccination programs are carried out in villages remote from a health centre. Vaccines are generally transported from a health centre having a specialised vaccine refrigerator to the (often remote) outreach location using passive, ice-lined vaccine containers.
One aim of the present invention is to provide an improved ice-lined vaccine storage device.
In accordance with one of its aspects, the present invention provides a cold storage device in accordance with claim 1. Other aspects are defined in other independent claims. The dependent claims define preferred or alternative features.
In one of its aspects, the present invention is based on the realisation that a significant improvement in the cold chain, particularly for vaccines and medical products, can be made by focussing on ice-lined cold storage devices and particularly on an improved arrangement for displaying data from a data system of an ice-lined cold storage device, notably temperature data and/or warning messages. The electronic paper display allows data to be displayed, and for a display of the data to be maintained, for cold storage devices which, during use, spend considerable periods of time during which they are not connected to an external power source and whose data systems must thus rely upon a data system battery. Furthermore, increased functionalities are being demanded of such data systems, for example, data communication functions, which provide an additional drain on the limited data system battery power available; thus, in requiring little power for their desired operation, the electronic paper display of the data system “frees up” the limited available electrical power for other data system usages.
As used herein, the term “electronic paper display” means a display whose display elements reflects light (unlike, for example LED displays whose LED display elements emit light) and which rely upon a static display using materials whose colour states are bi-stable so that the display continues to display an image without consuming power (unlike, for example, LCD displays which are volatile displays which require power to be applied to maintain the display of an image). The electronic paper display may be an electrophoretic display, a microencapsulated electrophoretic display, an electrowetting display; or an electrofluidic display. Preferably, the electronic paper display is configured to allow for partial refresh; this allows for low power consumption. The ice-lined cold storage devices, particularly passive ice-lined cold storage devices, are frequently used in bright sunlight; the use of an electronic paper display whose display elements reflect rather than emit light also facilitates reading of the display in such conditions.
The data from the data system which the electronic paper display is configured to display may include one or more of: an internal temperature of the cold storage compartment; a temperature outside the cold storage device; remaining battery charge available to the data logger; remaining charge of a data system battery; one or more alarms; an indication of the status of a lid of the cold storage device (eg closed, not closed); remaining autonomy of the cold storage device; telemetric data of the cold storage device.
In preferred embodiments, the cold storage device is a vaccine storage device configured to maintain its cold storage chamber at a temperature between +2° C. and +8° C.
As used herein, the term “ice-lined cold storage device” means a device configured to maintain its cold storage compartment within a controlled temperature range which is below the temperature of its surroundings based upon thermal insulation of the cold storage device and the provision of the ice lining which acts as a thermal capacitor to absorb heat from the cold storage compartment. Preferably, the ice lining is provided by one or more ice-packs. Such ice-packs are preferably filled with water; this allows the use of readily available materials, facilitates maintenance and replacement and allows the ice-lining to be provided by containers which can be filled locally rather than being transported ready-filled. Alternatively, ice-lining may be water-based, for example comprising at least 70 wt %, at least 80 wt % or at least 90 wt % water.
The invention is particularly suitable for passive cold storage devices. As used herein, the term “passive cold storage device” means a cold storage device which does not comprise a refrigeration circuit, for example an electrically powered refrigeration circuit, and relies upon passive means, notably pre-frozen ice-packs and the thermal insulation cold storage device, to maintain its cold storage compartment within a controlled temperature. When in use to store vaccines or other products, for example during transport of vaccines from a health centre to an outreach program, such passive cold storage devices are not connected to an external electrical energy source such as a mains electricity supply or solar panels. Consequently, no external electrical energy source is available to power the data system or to recharge a data system battery.
Particularly where the ice-lined cold storage device is a passive cold storage device, the device may be a transport device configured to store products, particularly vaccines, during transport. The passive cold storage device may have:
The invention is also suitable for regeneratively powered ice-lined cold storage devices. As used herein, the term “regeneratively powered cold storage device” means a cold storage device having an electrically power cooling circuit comprising a a compressor which is powered directly by solar panels or by a wind turbine, rather than being powered by connection to a mains electricity supply. Such a regeneratively powered, ice-lined cold storage device is preferably configured such that its electrically powered cooling circuit cools integrated ice-packs to form an ice-lining, so that, when the regenerative power is not available the pre-formed ice lining absorbs heat from its surroundings and contributes to maintaining the cold storage compartment within its desired temperature range. Preferably, the regeneratively powered cold storage device has a battery-free electrical cooling circuit, that is to say, an electrical cooling circuit which does not include a battery configured to provide power to a compressor of the cooling circuit (as opposed to a battery which provides power to a control circuit for controlling, for example, a compressor). This avoids issued associated with transport, replacement and disposal of such batteries.
Particularly for such a regeneratively powered, ice-lined cold storage device:
The ice-lining, notably for regeneratively powered ice-lined cold storage devices, preferably extends around at least 50%, at least 60%, at least 70% or at least 80% of periphery of the cold storage compartment; this helps to ensure consistency of the temperature within the cold storage compartment.
The cold storage device may be provided with an inner liner which preferably forms a continuous barrier between the cold storage compartment and the ice-lining. The inner liner may comprise a thermally insulating layer, for example of foam. The inner liner contributes to the control of heat flow from the cold storage compartment to the ice-lining to avoid over-chilling the cold storage compartment and provides a physical separation to avoid direct contact between vaccines and the ice-lining.
The data system is preferably integrated in the ice-lined cold storage device, that is to say is a permanent part of the cold storage device; this ensures its presence and use each time the cold storage device is used and avoids the risk of a non-integrated standalone system being lost or omitted.
The data system preferably comprises:
Such transmission is preferably wireless transmission. Thus, the data system may be configured, for example:
The data system is preferably powered by a data system battery integrated in the cold storage device. The data system battery is preferably rechargeable, for example from the solar power source where the cold storage device is a regeneratively powered cold storage device or from an external power source, for example a mains electricity supply, to which, for example a passive cold storage device may be periodically connected for this purpose. The data system battery may be replaceable. A configuration in which the data system battery has an operating voltage in the range 4.5 to 6 volts (eg 5 volts) and/or a battery capacity in the range 500 to 3000 mAh allows use of fairly small, readily available types of battery which will not add significant weight.
A configuration in which the electronic paper display has a refresh power requirement in the range 5 to 100 mW and/or a standby power which is less than 1 mW and preferably less than 0.1 mW; this is helpful to reduce the amount of power used by the display. Preferably, the electronic paper display is configured for partial refresh, that is to say that a portion of the display can be refreshed without requiring the entire display to be refreshed. This reduces the power required to change data displayed at a portion of the display.
The data system may be configured to be switchable between a) a standard display mode in which the electronic paper display is periodically updated to display a plurality of updated data from the data system and b) and an energy saving display mode in which the electronic paper display displays only a selected portion of the said data. For example, the display may be configured such that:
This allows a reduction in the amount of power required to change the display in the energy saving mode and thus ensures that more critical data is displayed.
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which:
An integrated, electronic paper display 20 is provided in the top of the lid 12 as part of a data system of the vaccine cooler 10 for displaying, for example, the temperature of a temperature probe (not shown) positioned within the vaccine storage compartment 16 and/or one or more warning messages, for example a warning regarding a rate of increase of temperature within the cold storage compartment 16 and/or a warning message received by a data system of the vaccine carrier 10 from an external network.
An example of the above-described ice-lined cold storage device 10 was configured and successfully tested using a GDEM029T94 electronic paper display manufactured by Dalian Good Display Co., Ltd. and having the following characteristics:
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019621.8 | Dec 2020 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/084818 | 12/8/2021 | WO |
