Capacitive power time-temperature profiling attachment for temperature-sensitive products like vaccines

Abstract

The present invention relates to a capacitive temperature monitoring attachment for monitoring the temperature chain of a temperature-sensitive product such as vaccines or food, comprising an electric power source, a temperature tracker powered by said electric power source, and a memory for storage of temperature tracking data from the temperature tracker, wherein said temperature tracker includes a temperature dosimeter for collecting temperature dose data indicative of phases of undesired temperatures above and / or below a temperature threshold and an application time thereof, and a temperature switch for switching-off powering of said temperature dosimeter by said electric power source in response to temperature.

Description

[0001] Capacitive power time-temperature profiling attachment for temperature-sensitive products like vaccines

[0002] The present invention generally relates to a temperature-monitoring attachment for monitoring the temperature chain of a product such as vaccines or food. More particularly, the present invention relates to a preferably capacitive time-temperature profiling attachment for monitoring the quality and / or potency of such temperature-sensitive products, comprising an electric power source, a time-temperature profiler powered by said electric power source and a memory for storage of time-temperature profile data from the time-temperature profiler.

[0003] A temperature-sensitive product such as vaccines, pharmaceuticals, meat, fish or other food and beverages often require cold chains for continuously keeping them at low temperatures or, more generally, within a predetermined temperature range over the product’s supply chain including shipments from the manufacturer to the distribution center, transport to the wholesaler and delivery to the customer. Such cold chain management also may relate to supply of the raw materials from which the product is manufactured. The product’s quality and potency may be affected detrimentally by high temperatures and sometimes also by low temperatures. For example, vaccines may lose their potency, whereas meat may go bad when subject to high temperatures and may lose quality when subject to sub-zero temperatures and getting frozen.

[0004] Usually, the deteriorating effect of interruptions of the cold chain does not only depend on the level of temperature as such, i.e. 5° or 10° or 20° above an upper threshold, but also depends on time, i.e. how long the product is subject to a temperature outside the allowed temperature window. Such dependency on time is due to buffering effects as a short temperature peak, for example when moving a product from a fridge storage room to a transporter fridge, may not get through the packaging into the product and may not warm the product itself. Time also may be relevant as deterioration of a product may slowly progress due to chemical reactions occurring at certain temperatures.

[0005] Therefore, it is the “dose” of undesired temperatures in terms of the temperature time profile on which deterioration of the product depends. Smaller temperature deviations applied to the product over a relatively longer time may cause a deterioration effect comparable to larger temperature deviations applied to the product over a shorter period of time. For example, a vaccine which should be stored under let’s say 2° Celsius may suffer in a comparable way when subject to 10° over one hour and when subject to 20° over half an hour.

[0006] Different types of cold chain monitoring devices are known from the prior art, wherein such prior art temperature monitoring devices suffer from being rather complicated or from lacking preciseness.

[0007] More particularly, so-called WM labels, i.e. vaccine-vial-monitoring labels, usually contain a heat-sensitive material that is placed on a vaccine to register cumulative heat exposure over time. Such WM labels may include one or more layers of a temperature-sensitive material such as an ink that irreversibly changes color upon deviation from a predetermined temperature range. For example, document EP 3 444 580 B1 discloses a temperature-monitoring attachment comprising a substrate on which a plurality of temperature indicators are arranged which temperature indicators are made from different types of temperature-sensitive inks which change color after different periods of time of temperature deviation from the set temperature range. However, such color-changing inks make it difficult to decide whether the product is good or bad since, usually, the human eye needs to make the decision if a certain color is present or not. Aside from low accuracy and reduced reliability due to required manual intervention and human observation error, such VVM labels are usually only applicable for monitoring temperatures exceeding an upper temperature threshold, but do not allow monitoring temperatures below a lower threshold.

[0008] Further, there are RFID monitoring devices providing for passive tracking of temperatures. Such RFID time-temperature profilers provide for low cost, but only intermittent tracking. In particular, temperatures are determined and recorded when, for example, the product is moved close to an RFID-reader at, for example, a goods receiving department or at a shipment facility. However, there is no continuous monitoring of excessive temperatures.

[0009] So as to achieve such continuous monitoring of excessive temperatures, data loggers may be used for continuously measuring and recording temperatures during distribution, whereas such sophisticated data loggers need sufficient, continuous energy supply and are rather bulky and expensive so they are usually only used in large-scale distribution situations such as transportation containers having data logger capable of continuously recording time and temperature.

[0010] So as to, however, allow monitoring temperatures of products individually, labels to be attached to the product are desired to achieve easy handling and individual temperature monitoring. Such labels, however, usually do not have sufficient power storage capacity to continuously power time-temperature profilers as conventional batteries providing for sufficient capacity are rather bulky or would need to be changed during the supply chain to be able to provide for full active tracking of temperatures.

[0011] It is therefore an objective underlying the present invention to provide for an improved temperature monitoring attachment that avoids disadvantages of prior art solutions and further develops the existing solutions. In particular, it would be desirable to reliably and precisely track any undesired temperature along the entire distribution chain of a product without needing bulky batteries. Another objective underlying the present invention is to provide for a small, thin, sheet-like label collecting digital data indicative of the dose of undesired temperatures applied to a product to allow for further processing of temperature data without human intervention.

[0012] According to the present invention, a temperature-monitoring attachment as defined by claim 1 is suggested, Preferred embodiments of the present invention are laid down in the dependent claims.

[0013] More particularly, it is suggested to have the time-temperature profiler monitor phases of undesired temperatures, but to switch off the time-temperature profiler during phases of acceptable temperatures to allow for tracking all relevant phases of possible deterioration of the product without requiring large power storage capacities. Such smart control of the time-temperature profiler provides for accuracy while getting along with small-sized electric power storages without necessitating frequently recharging.

[0014] According to an aspect, the time-temperature profiler is configured to quantify the dose of undesired temperatures in terms of a level of undesired temperatures and application times thereof to reflect the time temperature profile of phases of undesired temperatures. More particularly, the time-temperature profiler includes a temperature dosimeter for collecting digital temperature dose data indicative of temperatures above and / or below a temperature threshold and indicative of application time thereof. A temperature switch which may comprise at least one thermistor element may be provided for switching off powering of said temperature dosimeter by said electric power source in response to temperature.

[0015] Although only phases or chapters of product life of a relevant part of the product life such as the distribution chain are tracked, monitoring of detrimental temperatures is nevertheless complete and accurate as the temperature switch is configured to switch on powering of the time-temperature profiler and the temperature dosimeter during relevant phases of undesired temperatures.

[0016] So as to allow for individual temperature monitoring of single products, the temperature monitoring attachment may form a sheet-like label that is attachable to the product or a packaging thereof. More particularly, the temperature monitoring attachment may consist of such sheet-like label and does not require any additional accessories such as separate battery units or attachable antennas, but may include all relevant components allowing for temperature tracking and reading or transmitting the collected digital temperature dose data.

[0017] More particularly, the temperature monitoring attachment may form a flexible label comprising a multi-layered film sheet including an electronic circuit and / or electronic components and / or electric components on at least one of its layers. In particular, a battery, one or more thermistors and / or one or more capacitive elements may be integrated into such flexible label. According to an advantageous embodiment, said battery may be printed on one of said film layers.

[0018] Forming the temperature monitoring device as a sheet-like label allows for easy attachment onto the surface of the product to be monitored or its packaging. For example, the label may be glued onto the packaging of a vaccine. When the label is flexible, it may be attached to extend over an edge of the packaging and to be attached to two surfaces thereof by adhesive, so as to e.g. form a sort of seal for the packaging. For example, it may be attached to extend and to be glued to an opening lid and a neighboring frame portion to keep the opening lid closed and to necessitate breaking the label to open the lid.

[0019] Advantageously, the temperature monitoring label may be provided with an adhesive layer for gluing the label onto the product and / or its packaging.

[0020] So as to allow for detection or determination of an undesired temperature as well as the application time thereof, i.e. the time over which the product is subject to the undesired temperature, or allow for at least an approximation of the time temperature profile of the phases of undesired temperatures with rather simple digital equipment, the aforementioned temperature dosimeter may include an RC circuit, i.e. a resistor- capacitor-circuit, including at least one capacitor and at least one thermistor element to be driven or powered by said electric power source. More particularly, the electric power source may charge the at least one capacitor during phases of undesired temperatures so the charging level of the capacitor continuously increases as long as charging is effected. Consequently, the charging level is dependent on time. As known per se, a capacitor connected in series with a resistor forming an RC circuit, will charge up gradually through the resistor until the voltage across the resistor element reaches that of the supply voltage. Thus, the charging level of the capacitor is dependent on time and, when considering the time period before getting fully charged, the charging level is indicative of time. With the thermistor value defining in turn the charging time of the capacitor and with the thermistor itself changing values based on temperature, such dependency can be used so as to determine the application time of an undesired temperature and thus, to indicate the temperature dose.

[0021] So as to allow for small capacity of the at least one capacitor element of the RC circuit and thus, accurate and fine responding to temperatures, but nevertheless allow for dose tracking or time-temperature profiling over longer time periods, it is suggested to provide for a discharge circuit to discharge the at least one capacitor element in the RC circuit when having reached a certain charging level, for example when reaching the fully charged status, and consequently, repeatedly charging the at least one capacitor element in the RC circuit. So as to cumulatively detect the repeated charging cycles, a counter may be provided and configured to count the discharge cycles of the discharge circuit. For example, when the RC circuit is fully charged four times and discharged four times, the counter may count four charging / discharging cycles and consequently, the counted number four is indicative of the entire time temperature profile and the entire temperature dose of a phase of undesired temperature that caused such four times of charging the RC circuit.

[0022] Each time the capacitor is fully charged, it will increment the counter with its stored power and hence discharging itself completely. As the capacitor charging curve is previously known, each increment in the counter value reflects a certain integrated time temperature profile for the phase of undesired temperatures. When the counter value finally exceeds a certain counter value threshold, it indicates that the permissible dose of undesired temperatures applied to the product has been exceeded. In case of a vaccine, it may indicate that the vaccine is no longer effective or potent. The memory of the temperature monitoring attachment stores such binary information so it can be read out before using the product.

[0023] So as to reflect the level of temperature during phases of undesired temperatures, the RC circuit may be configured to adjust the charging speed or charging rate of the at least one capacitor to the temperature level. In particular, the charging circuit with an NTC thermistor with lower values at higher temperatures facilitates faster charging of the capacitor for relatively higher temperatures and to provide for slower charging of the capacitor for relatively lower temperatures, wherein the aforementioned higher and lower temperatures are still undesired temperatures above the temperature threshold. If undesired temperatures below a lower threshold are to be monitored, the charging circuit defined by a second ‘PTC’ thermistor may be configured to allow for charger fasting for lower temperatures and slower charging for higher temperatures.

[0024] In other words, the charging circuit may be configured to increase the charging speed for larger deviations of the current temperature from the allowed temperature window and to decrease charging speed for smaller deviations of the current temperature from the allowed temperature window. Thus, when the current temperature is further away from the allowed temperature range, the capacitor is charged faster, whereas the capacitor is charged slower for current temperatures closer, but still outside the allowed temperature range.

[0025] Such charging circuit may include a transistor switching circuitry to which at least one thermistor element and at least one resistance element may be connected, said thermistor and resistance elements may together form a temperature sensitive voltage divider. When it is sufficient to monitor only an upper temperature threshold or only a lower temperature threshold, it is sufficient to have one such pair of thermistor element and resistance element. For example, for monitoring the temperature chain for frozen meat, it may be sufficient to monitor temperatures above 0°, and it may not be necessary to monitor a lower temperature threshold. On the other hand, when monitoring an upper temperature threshold as well as a lower temperature threshold, a first pair of thermistor and resistance elements may be used for monitoring the upper threshold and a second pair of thermistor and resistance elements may be used for monitoring the lower temperature threshold.

[0026] More particularly, on the one hand a pair of thermistor and resistor elements together forming a voltage divider may form a temperature switch for switching off and switching on powering of the time-temperature profiler depending on temperature, wherein such pair of thermistor and resistor elements may be arranged between the electric power source and a transistor switching circuit to enable and disable powering of the aforementioned RC circuit for tracking undesired temperature doses.

[0027] On the other hand, a pair of thermistor and resistor elements may be provided for adjusting charging speed of the aforementioned RC circuit in response to temperature as explained above. Such pair of thermistor and resistor elements may be arranged between the capacitor to be charged and the aforementioned transistor switching circuitry to become effective and to adjust charging speed when the temperature switch has switched on powering of the circuitry.

[0028] In order to further save energy of the electric power source, the aforementioned counter may be connected to a transistor circuitry and / or may be configured so as to prevent the temperature dosimeter from being operated when the maximum allowable number of charging cycles of the capacitor have been counted, i.e. when the maximum temperature dose has been determined. Even when further phases of undesired temperatures occur, there will be no repowering of the time-temperature profiler which is switched into a deep sleep mode when the counter has reached the maximum number of counts.

[0029] So as to allow for easy checking the determined temperature dose of undesired temperatures, the temperature monitoring attachment may be provided with data com- munication device such as an RFID device and / or an NFC device to allow transmission of the stored temperature dose data through an onboard antenna, such as a printed antenna, from the temperature monitoring attachments memory to another data processing device such as a smartphone or a data processing station of a distributer unit in the distribution chain.

[0030] For example, the memory of the temperature monitoring device may be provided with such RFID and / or NFC device and may be provided with an antenna allowing for transmission of these stored data.

[0031] According to another aspect, the temperature monitoring attachment may be provided with a tamper protection device. Such tamper protection device may be configured to be responsive to breaking anyone of the electronic circuits and / or electronic components and / or electric components, in particular it may be responsive to breaking the label, when for example opening the packaging of the product when the label is attached to an opening lid or extending over an edge of the packaging as mentioned before.

[0032] More particularly, the temperature monitoring attachment may be provided with a tamper circuit powered by the electric power source and configured to register in the memory digital tamper data such as a date and / or time of a tempering activity such as breaking the label. However, such storage function is not necessary and the tamper circuit may be configured, for example, as a conductive line, for example a simple copper trace, to monitor tampering of the label. When there is an unauthorized opening of the packaging, the tamper circuit in terms of the conductive line will be broken. Such tamper circuit may be printed onto one of the layers of the aforementioned multilayered film product forming the label.

[0033] The present invention will be described in greater detail in combination with an advantageous embodiment illustrated in the following drawings:

[0034] Fig. 1 : A perspective view of a temperature monitoring attachment forming a flexible label according to an advantageous embodiment as attached to the packaging of a vaccine, wherein said temperature monitoring label forms a seal sealing the vaccine’s packaging,

[0035] Fig. 2: the temperature monitoring attachment of figure 1 , wherein partial view a shows a top view of the temperature monitoring label and partial view b shows a plane view of a layer of said label onto which a battery, electronic circuits, an antenna for data communication and energy harvesting and a temper protection circuit are printed,

[0036] Fig. 3: a diagram showing the architecture of the components of the temperature monitoring attachment of the preceding figures,

[0037] Fig. 4: a diagram of the temperature sensitive switch and charging controller for switching on tracking of undesired temperatures in response to temperature,

[0038] Fig. 5: another illustrative example of the architecture of the electronic functional components of the temperature monitoring attachment, and

[0039] Fig. 6: a diagram showing a time temperature profile having phases of allowed temperatures and phases of undesired temperatures to illustrate tracking of the temperature doses of the phases of undesired temperatures in terms of collecting digital data indicative of undesired temperatures and application time thereof.

[0040] As can be seen from figures 1 and 2, the temperature monitoring attachment 1 may be formed as a thin, sheet-like label 2 or tag which may be attached to a product itself or to a packaging 3 thereof. Advantageously, the label 2 may be flexible and / or deformable, and in particular foldable, so it may be attached to different sides of a boxlike packaging 3 or wrapped around / attached to convex contours like pipe-shaped packagings and / or extend over an edge of a packaging box. In particular, it may be glued onto an opening lid 4 and a neighboring frame portion of the packaging 3 so as to form a seal that needs to be broken when opening the opening lid 4. The label 2 may be provided with an adhesive layer forming, for example, a bottom surface of the label 2.

[0041] The label 2 may be a multilayer thin film product comprising a plurality of layers, in particular film layers, wherein electronic and / or electrical components may be arranged on at least one of said layers, as it is shown by Fig. 2b.

[0042] More particularly, an electric power source 6 such as a battery and / or electronic circuits 7 for temperature tracking and / or an antenna 8 for data transmission and / or energy harvesting, and / or a tamper protection circuit 9 may be arranged on one of the layers of such multilayer label. For example, the battery may be printed onto one of the layers.

[0043] The architecture of the electronic and electric components of the temperature monitoring attachment 1 may be seen from figures 3, 4 and 5 in greater detail.

[0044] In particular, the electronic circuits 7 for temperature tracking may include a timetemperature profiler 10 that can be powered from said electric power source 6 and a memory 11 for storage of digital time-temperature profile data determined by said time-temperature profiler 10.

[0045] More particularly, said time-temperature profiler 10 includes a temperature dosimeter 12 for collecting temperature dose data indicative of temperatures above and / or below a temperature threshold and application time thereof.

[0046] Said temperature dosimeter 12 includes an RC circuit 13 including at least one capacitor 14 connected in series to form the RC circuit so the capacitor 14 will charge up gradually through the thermistor element 15 until the voltage across the capacitor element reaches that of the voltage supply source. A plurality of thermistors comprising of NTC and PTC can enable the temperature dosimeter to record doses effectively for temperatures exceeding both upper and lower thresholds respectively. More particularly, as illustrated by Fig. 3, the charging circuit for charging the capacitor 14 may be configured to be temperature-sensitive, wherein the charging circuit may include at least one thermistor Rth3 to control the charging speed. As it is known per se, a thermistor changes its resistance with temperature changes, wherein, for example, NTC thermistors exhibit a predictable decrease in their resistance with increase in temperature. Thus, when temperature increases, charging resistance decreases and thus, faster charging of the capacitor 14 is allowed for relatively higher temperatures. For the temperatures below a lower threshold, an inverse operation may be performed through a PTC thermistor and the same charging capacitor, wherein faster charging of the capacitor 14 is facilitated for relatively lower temperatures.

[0047] Charging of the capacitor 14 is powered from the electric power source 6 which may be the printed battery mentioned before. However, powering is switched on and switched off depending on temperature by means of a temperature-sensitive switch 16 which is shown in figures 3-5. More particularly, such temperature-sensitive switch 16 may include at least one pair of thermistor Rth1 , Rth2 and at least one resistor element Rdivl , Rdiv2 arranged as voltage divider and connected to a transistor switching circuit 17, cf. Fig. 4. Such at least one pair of thermistor and resistor elements form a voltage divider preventing powering of the time-temperature profiler 10 before temperature has reached or exceeded a certain threshold temperature 20.

[0048] More particularly, as becomes clear from Fig. 4 and Fig. 5, the temperature switch 16 including the at least one pair of thermistor and resistor elements allows power from the electric power source 6 to charge the capacitor 14 only when a sufficient bias voltage for the transistor switching circuit 17 has been reached or exceeded due to temperature becoming high enough and, thus, resistance of the thermistor Rth1 , Rth2 becoming low enough. When the transistor switching circuit 17 is in saturation, i.e. in the “on” operating status, the power source 6 is allowed to charge the capacitor 14. On the other hand, when the temperature is still below the aforementioned threshold temperature 20, no sufficient biasing voltage for the transistor switching circuit 17 is provided and, thus, no power from the power source 6 may get to the capacitor 14.

[0049] When the temperature switch 16 has switched on powering of the RC circuit to charge the capacitor 14, speed of such charging is controlled and adjusted by thermistor element Rth3 of the charging circuit, cf. Fig. 3, independency on temperature. Again, as thermistor Rth3 changes its resistance with temperature changes, in particular decreases its resistance with increasing temperatures, faster charging is allowed for higher temperatures, whereas slower charging is allowed for lower temperatures.

[0050] As can be seen from figures 3 and 5, the capacitor 14 may be discharged via a discharger 18 connected to the capacitor 14, wherein such discharger 18 is configured to effect discharging only when the capacitor 14 has reached a certain charging level.

[0051] In particular, the discharger 18 may be configured to initiate discharging of the capacitor 14 each time when the capacitor 14 has been fully charged.

[0052] As can be seen from figures 3 and 5, said discharger 18 includes a counter 19 which can be powered by the power stored in the capacitor 14. Said counter 19 is incremented each time when discharging the capacitor 14 so the counter 19 is configured to count the number of discharging cycles of the capacitor 14.

[0053] Such counted number of discharging cycles is then stored in memory 11 and is indicative of the temperature dose to which the temperature monitoring attachment 1 has been subject to as it reflects the total cumulative charging load of the capacitor 14 as applied to the capacitor in multiple charging cycles.

[0054] After having being discharged, the capacitor 14 may be charged once again if the temperature is still - or once again - above the threshold temperature - or in case of monitoring a lower threshold temperature, below such threshold temperature. In such case, i.e. when the current temperature is still outside the allowed temperature window, the temperature switch 16 is still in its “on” condition enabling powering of the CR circuit and, thus, charging the capacitor 14. Such recharging (after a preceding discharge operation) continuous until the capacitor is again fully charged or reaches the predetermined charging level so another discharging operation may take place and, thus, the counter 19 is incremented once again.

[0055] Such discharging and recharging procedure is repeated as long as the current temperature is still outside the allowed temperature window and, thus, the counted member of discharging procedures is indicative of the cumulative charging load of the capacitor 14 and, thus, indicative of the temperature dose.

[0056] As becomes clear from Fig. 6, repeating the charging-and-discharging-cycles as described before approximates the area below the temperature-time-curve and above the threshold temperature shown in Fig. 6, wherein the threshold temperature is illustrated to be approximately -2°. In other words, repeatedly charging and discharging the capacitor 14 integrates the time temperature profile during the phases of undesired temperatures as it depends on the level of the undesired temperature as well as on the application time of such undesired temperature.

[0057] More particularly, Fig. 6 shows a temperature curve starting at 0 min. at approximately -5° and thus, below the threshold temperature 20 of about -2°. The temperature then starts increasing at about 2 min., but is still below the temperature threshold 20. At about 4 min., the current temperature becomes higher than the threshold temperature 20 and continuous to increase to reached at about 8 to 11 min., and then starts decreasing, but is still above the temperature threshold 20 until about 15 min. In the phase between about 15 and 22 min., the current temperature is below the threshold temperature 20, wherein another phase of undesired temperature above the threshold temperature 20 occurs in the period from about 22 to 26 min., cf. figure 6. Thus, as it is apparent from figure 6, phases of undesired temperatures above the temperature threshold 20 and phases of allowable temperatures below the temperature threshold 20 alternate with each other. Due to the above described temperature switch 16, only the phases of undesired temperatures are tracked, whereas the time-temperature profiler 10 is disabled and powered off during phases of acceptable temperatures.

[0058] Although figure 6 shows only an upper temperature threshold, it is needless to say that also a lower temperature threshold may be monitored in a corresponding manner, wherein the time-temperature profiler 10 is powered during phases in which the temperature is below the lower threshold.

[0059] When the counted number of discharging cycles has reached a predetermined maximum number indicative of the maximum temperature load or temperature dose allowed for the respective product, the time-temperature profiler 10 may be completely disable or switched off. In particular, the counter 19 may be configured to give a signal to the transistor switching circuit 17 which may disable the powering of the RC circuit and thus charging of the capacitor 14 until a reset is effected. Thereby, unnecessary tracking cycles may be avoided and energy stored in the battery may be saved.

[0060] As mentioned before, a tampering protection circuit 9 may be provided, wherein such tampering protection circuit 9 may include, for example, a tamper protection line extending along the label 2, cf. figure 2b, wherein such tamper protection line may extend over the entire length and / or the entire width of the label 2 to fully monitor any breaking of the label 2.

Claims

Claims1. Time-temperature profiling attachment for monitoring the quality and / or potency of a temperature-sensitive product such as vaccines or food, comprising an electric power source (6), a time-temperature profiler (10) powered by said electric power source (6), and a memory (11 ) for storage of time-temperature profile data from the time-temperature profiler (10), characterized in that said time-temperature profiler (10) includes a temperature dosimeter (12) for collecting temperature dose data indicative of phases of undesired temperatures above and / or below a temperature threshold (20) and an application time thereof, and a temperature switch (16) for switching-off powering of said temperature dosimeter (12) by said electric power source (6) in response to temperature.

2. Time-temperature profiling attachment according to the preceding claim, wherein the temperature dosimeter (12) includes an RC circuit (13) comprising at least one capacitor (14) and at least one NTC thermistor and / or PTC ther-mistor (15) arranged in series, which together comprise or form part of a temperature-sensitive charging circuit for adjusting the charging speed of the capacitor (14) defined by the changing thermistor (Rth3) value in response to the temperature, and to be powered by said electric power source (6) when the temperature switch (16) allows powering of the temperature dosimeter (12) by said electric power source (6).

3. Time-temperature profiling attachment according to the preceding claim, wherein the temperature dosimeter (12) further includes a discharger (18) comprising a counter (19) configured to discharge the capacitor (14) when having been charged to a predetermined charging level and counting the number of discharging cycles, wherein the memory (11 ) and the counter (19) are configured to store and update the number of counted discharging cycles as an indicator of the temperature dose.

4. Time-temperature profiling attachment according to the preceding claim, wherein said charging circuit is configured to increase charging speed of the capacitor (14) through decreased values of the NTC thermistor for temperatures over an upper threshold and / or through decreased values of the PTC thermistor for temperatures below a lower threshold, for increasing deviations of the current temperature from the allowed temperature window and to decrease charging speed through increased values of said NTC or PTC thermistor for decreasing deviations of the current temperature from the allowed temperature window.

5. Time-temperature profiling attachment according to one of the two preceding claims, wherein said charging circuit includes at least one thermistor (RTH3) for modifying the charging time for fully charging the capacitor (14) in response to temperature.

6. Time-temperature profiling attachment according to anyone of the preceding claims, wherein said temperature switch (16) is configured to switch-off pow-ering of the temperature dosimeter (12) when the temperature is within a predetermined allowable temperature window and to switch-on powering of the temperature dosimeter (12) when the current temperature is outside said allowable temperature window.

7. Time-temperature profiling attachment according to anyone of the preceding claims, wherein said temperature switch (16) includes at least one thermistor (RTH1 , RTH2) for modifying a transistor’s bias voltage for a transistor switching circuitry (17) in response to temperature.

8. Time-temperature profiling attachment according to the preceding claim, wherein said temperature switch (16) includes at least one pair of thermistor and resistor elements (RTH1 , RDIV1 ; RTH2, RDIV2) forming a voltage divider between the electric power source (6) and the transistor switching circuitry (17).

9. Time-temperature profiling attachment according to claim 6 or 7 or 8, wherein said temperature switch (16) includes two thermistors (RTH1 , RTH2) and two resistor elements (RDIV1 , RDIV2) forming a first pair of thermistor and resistor elements configured to switch-off powering of the temperature dosimeter (12) when the temperature exceeds an upper threshold temperature and a second pair of thermistor and resistor elements (RTH2, RDIV2) configured to switchoff powering of the temperature dosimeter (12) when the temperature is below a lower threshold temperature.

10. Time-temperature profiling attachment according to anyone of the preceding claims, wherein the memory (11 ) is connected to a data communication interface, in particular to a communication module or a combination of communication modules, for communicating the stored temperature dose data to an external data processing device such as a mobile phone, through an onboard antenna, in particular a printed onboard antenna (8).

11. Time-temperature profiling attachment according to the preceding claim, wherein said temperature monitoring attachment forms a sheet-like label (2) attachable to the product or a packaging (3) thereof.

12. Time-temperature profiling attachment according to the preceding claim, wherein said label is flexible and comprises a multi-layered film sheet including at least one electronic circuit (7) printed on at least one of its layers, comprising of printed and / or SMD electronic components.

13. Time-temperature profiling attachment according to the preceding claim, wherein said battery is printed on one of said layers of said multilayered film sheet.

14. Time-temperature profiling attachment according to anyone of the preceding claims, further comprising an adhesive surface layer for gluing the temperature monitoring attachment to the product or a packaging (3) thereof.

15. Time-temperature profiling attachment according to anyone of the preceding claims, further comprising a tampering protection circuit (9) for indicating tampering activities.

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