Method and system for determining the condition of a time-temperature indicator

Abstract

A device is presented for use in controlling the quality of a perishable object, while progressing on its supply line, by monitoring the condition of a time-temperature indicator (TTI) associated with the object. The device comprises a sensing assembly for detecting a response of the TTI to a predetermined stimulus and generating measured data representative thereof, said measured data being indicative of the condition of the TTI, thereby enabling the determination of the remaining shelf life of the TTI and thereby any perishable good to which it is attached and calibrated.

Claims

1. A system for monitoring a monitored object while progressing on a supply chain, the monitored object being a perishable good, the system comprising an identification object physically associated with the monitored object, wherein said identification object comprises a time-temperature indicator (TTI) to assess the freshness status of the perishable good, the system further comprising a plurality of nodes, the monitored object being monitored at a plurality of said nodes and the monitored object being progressed between said plurality of nodes forming the supply chain, wherein physical control of said monitored object changes at each node, each node comprising: a. sensing assembly for detecting a response of the TTI to a predetermined stimulus, which response is indicative of the full time-temperature history the TTI has experienced, and generating measured data representative of said response, such that said measured data is quantitatively indicative of the condition of the TTI, and thus the freshness status of the perishable good being monitored; b. a communication utility in communication with said sensing assembly for translating said measured data into an output signal providing a quantitative indication of the freshness status of the perishable good being monitored; c. a control unit, communicating with said communication utility, said control unit comprising a data processing and analyzing utility for determining the remaining shelf life of the monitored perishable good at a given temperature according to the value of said output signal received from said communication utility, the determination of remaining shelf life being accomplished without the requirement of knowledge of the starting time of the perishable good into the supply chain; and d. a controller for determining whether the remaining shelf life of the monitored object is sufficient for progressing the monitored object from a current node to a subsequent node in the supply chain according to a handshake protocol, wherein the monitored object is transferred from said current node to said subsequent node according to the remaining shelf life.

2. The system of claim 1, wherein said identification object is selected from the group consisting of a label, a tag and packaging material.

3. The system of claim 2, wherein said sensing assembly comprises a light source generating predetermined incident light, and a light detector, and wherein the detected response includes a light response of the TTI to said predetermined incident light.

4. The system of claim 3, wherein said light detector measures spectral data.

5. The system of claim 3, wherein said light response is in the form of certain color saturation.

6. The system of claim 3, wherein said light response includes reflections of the incident light.

7. The system of claim 3, wherein said light response includes light transmitted through the TTI.

8. The system of claim 3, wherein said incident light is in a visible spectral range.

9. The system of claim 8, wherein said light source is a flash lamp.

10. The system of claim 1, wherein said sensing assembly and said communication utility are located remotely from said control unit.

11. The system of claim 1, wherein the supply chain is a chill chain.

12. The system of claim 11, wherein said identification object is printed upon the monitored object itself.

13. The system of claim 11, wherein said communication utility produces said output signal in the form of at least one of electrical, optical, RF and acoustic signal.

14. The system of claim 1, wherein said identification object comprises a machine readable pattern, at least one feature thereof being configured as said TTI.

15. The system of claim 11, wherein said controller determines at least a minimum remaining shelf-life according to said handshake protocol, such that the monitored object is not progressed along the supply chain if said minimum remaining shelf-life is not met.

16. The system of claim 15, wherein said data processing and analyzing utility determines a quantitative measurement of said remaining shelf-life and wherein said controller determines at least said minimum remaining shelf-life according to said quantitative measurement.

17. The system of claim 16, wherein said controller determines at least a minimum shelf life according to said quantitative measurement.

18. The system of claim 17, further comprising a receiving party at an end node at the end of the supply chain, said receiving party determining whether to accept the monitored object.

19. The system of claim 18, wherein said receiving party comprises an end customer for purchasing the monitored object and for visually inspecting the TTI to determine the remaining shelf life at a given temperature according to said status of the TTI.

20. The system of claim 18, wherein said receiving party comprises a supermarket.

21. The system of claim 1, wherein said supply chain comprises a plurality of physically separated facilities, such that said plurality of nodes comprises at least two different physically separated facilities, wherein said controller determines whether the remaining shelf-life of the monitored object is sufficient for physically progressing the monitored object from a current node to a subsequent node in the supply chain.

22. The system of claim 14, wherein at least one node further comprises a machine-readable pattern reader for reading the pattern on said identifying object to identify the monitored object.

23. A system for monitoring a monitored object while progressing on a supply chain, the monitored object being a perishable good, the system comprising an identification object physically associated with the monitored object, wherein said identification object comprises a time-temperature indicator (TTI) to assess the freshness status of the perishable good, the system further comprising a plurality of nodes, the monitored object being monitored at a plurality of said nodes and the monitored object being progressed between said plurality of nodes forming the supply chain, wherein physical control of said monitored object changes at each node, each node comprising: a. sensing assembly for detecting a response of the TTI to a predetermined stimulus, which response is indicative of the full time-temperature history the TTI has experienced, and generating measured data representative of said response, such that said measured data is quantitatively indicative of the condition of the TTI, and thus the freshness status of the perishable good being monitored; b. a communication utility in communication with said sensing assembly for translating said measured data into an output signal providing a quantitative indication of the freshness status of the perishable good being monitored; c. a control unit, communicating with said communication utility, said control unit comprising a data processing and analyzing utility for determining the remaining shelf life of the monitored perishable good at a given temperature according to the value of said output signal received from said communication utility, the determination of remaining shelf life being accomplished without the requirement of data other than said output signal corresponding to said measured data; and d. a controller for determining whether the remaining shelf life of the monitored object is sufficient for progressing the monitored object from a current node to a subsequent node in the supply chain according to a handshake protocol, wherein the monitored object is transferred from said current node to said subsequent node according to the remaining shelf life.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order to understand the invention and to see how it may be carried out in practice, preferred embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a block diagram of a device according to one embodiment of the invention;

(3) FIG. 2 is a block diagram of a device according to another embodiment of the invention;

(4) FIG. 3 is a schematic illustration of a label attachable to an object and carrying a barcode-like pattern with at least one TTI;

(5) FIG. 4 schematically illustrates an objects' supply chain including a plurality of nodes (points) each utilizing the device of the present invention for determining the object condition when arriving at the chain node;

(6) FIGS. 5A and 5B illustrate two examples, respectively, of the time variation of responses from different types TTIs at respective standard temperature conditions; and

(7) FIG. 6 more specifically illustrates the time variations of the TTI condition at different temperatures.

DETAILED DESCRIPTION OF THE INVENTION

(8) Referring to FIG. 1, there is illustrated by way of a block diagram a device 10 according to one embodiment of the invention for use in determining the condition of a time-temperature indicator (TTI) 12. The device 10 is configured for detecting a response (light response in the present example) of the TTI to predetermined incident light (constituting an external field or stimulus) and generating measured data MD representative thereof. This measured data is indicative of the condition of the TTI and is thus indicative of the condition of an object (not shown) the TTI is associated with.

(9) The device 10 comprises a light source 14; and a light detector 16. A control unit 18 is provided being connectable to the output of the detector, and preferably also connectable to the light source for operating the same. The light source and detector are housed in a chamber 15 designed to appropriately diffuse the incident light in a manner that it will homogeneously irradiate the active point (active region) of the TTI, as well as to direct the collected light response, originating from the active point, to the detector. The detector 16 is accommodated so as to collect the response of the TTI (e.g., reflection of the incident light, excited light, or light transmitted through the TTI). The light source 14 is of the kind generating incident light of a predetermined spectral range in accordance with the TTI type. For example, this may be a flash lamp operating in the visible spectrum. The spectral properties of the incident light beam and the collected light are electronically transferred to the control unit 18 through an interconnecting cable (or wireless transmission).

(10) The control unit 18 is an electronic module including inter alia a memory utility, a data processing and analyzing utility, and a data presentation utility (e.g., display, indicator). The memory utility stores certain reference data including inter alia the spectral data and calibrated time-temperature color profile. The reference data may include information regarding various types of TTI. The data processing and analyzing utility is preprogrammed to be responsive to the measured data to determine the optical properties of the active point of the TTI and thus determine the condition of the TTI, and generate an output signal indicative thereof. This output signal is then appropriately formatted to be presented to the user via the data presentation utility (including one or more output ports).

(11) It should be noted that the device energy needed to operate the device 10 is supplied by an energy source (not shown) that may be a battery or any other electrical source.

(12) It should also be noted that the technique of the present invention is not limited to any specific type of the TTI and can be used for automatically monitoring the condition of any TTI. The type and operating parameters of the stimulus are selected in accordance with the TTI type.

(13) An example of a photoactivated TTI that may be used in the device of the present invention is that produced by Lifelines, as disclosed in U.S. Pat. No. 4,737,463. According to this patent, a thermally inactive diacetylenic salt (or a mixture of such salts) is mixed, in a polymeric matrix, with a material that generates acid upon exposure to light. Photoexcitation causes the formation of a thermal active free diacetylenic acid. Following this activation step, a progressive color development occurs at a rate that increases with temperature. Another example is the TTI developed in part by one inventor of the present invention and described in WO 99/39197. According to this technique, a planar time-temperature integrator consisting of a matrix and at least one reversible indicator embedded therein is arranged in the area of the substrate. The indicator has photochromic properties based on transfer reactions. On the basis of such properties, the indicator is coloured in photoinduced manner and a time-dependent and temperature-dependent discolouration occurs. The degree of time-related or temperature-related discolouration is measured and the product quality is concluded therefrom.

(14) FIG. 2 illustrates a device 100 according to another example of the present invention. To facilitate understanding, the same reference numbers are used for identifying those components which are similar in the examples of FIGS. 1 and 2. In this example, the device 100 is in the form of a hand-held optical probe including a light source 14, a photodetector 16, a battery 17, and a communication utility 20. The communication utility 20 is connected to the output of the photodetector for receiving measured data MD representative of the detected light response of a TTI, and is appropriately configured for translating the measured data into an output signal of the kind to be wirelessly transmitted to a stand-alone control unit 118. This output signal may be RF, IR or acoustic signal. The control unit 118 is thus equipped with a suitable communication utility for communicating with the device 100.

(15) Reference is now made to FIG. 3 illustrating an optically readable pattern 22 (e.g., barcode), which is configured to be representative of object-related information and has at least one feature in the form of a TTI 24. This pattern 22 is printed on a substrate 200 that may be a label, tag or packaging material, or may be the object itself.

(16) The pattern 22 is thus representative of the object-related data, including data indicative of the object's remaining shelf life at a given temperature. Collecting a light response of the pattern 22 (e.g., by scanning the pattern) allows for reading the object-related information and detecting the condition of the TTI, and thus detecting the freshness condition of the object. In this case, a suitable barcode reader may include the sensor device of the present invention as described above and as exemplified in FIGS. 1 and 2. The sensor device (or stand alone control unit associated with the sensor device) is appropriately preprogrammed with a certain protocol for determining, from the response of the TTI, the remaining shelf life of this TTI, and generating an output signal indicative thereof, thus enabling to either accept or reject the product.

(17) FIG. 4 shows how the present invention can be used for monitoring the object condition while progressing on a supply line. The freshness status of the perishable good may be expressed in its remaining lifetime at a given temperature. This data may be useful in supply line regulations as well as correlating deviations from regulations to specific segments of it. FIG. 4 schematically illustrates an object 30 while progressing on a supply chain 300. The object 30 carries a TTI or a pattern 22 (machine readable code) including TTI-related pattern feature(s). The TTI or the pattern with TTI is printed on the object or on a label/tag attached to the object, or the object packaging material. The supply chain 300 includes several nodes, generally at 32, each utilizing the TTI/pattern reading device of the present invention (for example device 10 or 100 exemplified above) for detecting the TTI condition (and thus the object condition) when arriving at said node.

(18) The predetermined TTI condition varies from point to point of the chill chain supply line which can be monitored in accordance with a preset handshake protocol. This protocol may define for each point (node) where a product changes hands, a nominal (plus minimal and maximal) color condition. Hence, at each point of the supply line, the detected current condition of the TTI gives indication of the remaining shelf life of the TTI at a given temperature.

(19) FIG. 5A shows the time response of “Fresh Check” TTI (produced by Lifelines) at 4° C. The active matrix of the TTI changes its color from light to dark, in a process that at 4° C. takes 185 hours. The points in the graph of FIG. 5A represent values corresponding to the readings obtained from the TTI at different time intervals, starting when bringing the TTI to a temperature of 4° C. from its storage temperature, thus setting its “time zero”. Along the lifespan of the TTI, the color of the TTI active matrix progresses in a predictable fashion as a function of the time.

(20) FIG. 5B shows the time response of the ITT of another type (developed in part by one inventor of the present invention and disclosed in WO 99/39197) at 2° C. The active matrix of the TTI changes its color from dark blue to white, in a process that at 2° C. takes 500 hours. The points in the graph represent the values of readings of the TTI response at different time intervals after charging the TTI using UV light, thus setting its “time zero”. Along the TTI lifespan, the color of the active matrix of the specific TTI progresses in a predictable fashion as a function of the time.

(21) FIG. 6 more specifically illustrates the time-temperature behavior of this TTI (being sensed as the TTI response to 365 nm incident radiation). Positions a to d correspond to the TTI variations during the time period of 13 days under the temperature conditions of, respectively, 2° C., 5° C., 7° C. and 20° C., and position e shows the TTI conditions of position b but obtained using a green filter. As shown, the color of the TTI active matrix varies in a predictable fashion from dark blue to white as a function of the time and temperature.

(22) The following are two specific, but not limiting, examples of using the chill chain handshake protocol in accordance with the present invention for controlling the TTI condition (i.e., the object condition) all along the supply chain.

Example 1

(23) In this example, the TTI used for demonstrating the monitoring and control of the chill chain using a handshake protocol in accordance with the present invention, is the “Fresh Check” Time Temperature Indicator produced by Lifelines. The specific time response of this TTI at 4° C. is shown in FIG. 5A.

(24) In a simulation of a chill chain condition, the TTI is transferred from one person (node of the chain) to another in a way that none of them could know the time-temperature history of the TTI prior to the time point he received the TTI. Each of the participants is equipped with a reading device of the present invention appropriately calibrated to the specific TTI for reading data indicative of the TTI (or the entire pattern including the TTI-feature).

(25) The standard conditions of the specific chill chain determined for the experiment are as follows: Each party (at each node of the chain) is entitled to refuse acceptance of the goods transported along the chill chain, if the remaining standard shelf life (RSSL) is shorter than a certain minimal value. This is depicted in Table 1 exemplifying the minimal remaining standard shelf life (MRSSL) at 4° C.:

(26) TABLE-US-00001 TABLE 1 Remaining standard shelf life (hrs) Station Minimum Maximum Color a 180 0.17 b 160 0.20 c 128 0.23 d 109 0.26 e 83 0.30

(27) First experiment—a TTI (product with TTI) is kept at a constant temperature of 4° C. all along the experiment:

(28) At the starting node a of the supply chain, user A (representing the company that produces the product) brings the TTI from its storage temperature to the 4° C. temperature, thus setting its “time zero”. At that moment, user A measures the TTI response to incident light (e.g., the color of the TTI) in a manner described above, thus confirming that the response (color) of the TTI is lower than 0.17 O.D., corresponding to the MRSSL at 4° C. of 180 hours. The ITT then progresses on the supply chain to node b.

(29) At node b, user B (representing the first transporter that transports the goods from the producer to the first warehouse) is responsible for controlling the goods' condition arriving from the producer (node a). Upon accepting the goods from user A, user B measures the response (color) of the TTI and detects that the color of the TTI is lower than 0.20 O.D., representing the minimal value (MRSSL at 4° C.) of 160 hours.

(30) The product with TTI is then passed to node c. Here, user C (representing the warehouse), upon accepting the goods from user B, measures the ITT response (color), confirming that the color of the TTI is lower than 0.23 O.D., representing the minimal value (MRSSL at 4° C.) of 128 hours.

(31) The product with TTI is then passed to node d where the second transporter is responsible for transporting goods from the warehouse to a supermarket store-room. Upon accepting the goods from user C, user D measures the color of the TTI, confirming that the color of the TTI is lower than 0.26 O.D., representing the MRSSL at 4° C. of 109 hours.

(32) The product with TTI is then passed to node e, constituting the supermarket shelf. Upon accepting the goods from node d, user E at node e measures the color of the TTI, confirming that the color of the TTI is lower than 0.30 O.D., representing a MRSSL at 4° C. of 83 hours.

(33) Second experiment—a TTI (product with TTI) is kept at a constant temperature of 4° C. all along the experiment, except for that of the warehouse, where the TTI is exposed for an unknown period of time to the room temperature.

(34) At the starting node a, user A (a company that produces the product) brings the TTI from its storage temperature to a temperature of 4° C., thus setting its “time zero”. At that moment, user A measures the color of the TTI, confirming that it is lower than 0.17 O.D., representing a MRSSL at 4° C. of 180 hours.

(35) The product with TTI is then passed to node b representing the first transporter that transports the products from the producer to the first warehouse. Upon accepting the goods from node a, user B measures the color of the TTI, confirming that the color of the TTI is lower than 0.20 O.D., representing a MRSSL at 4° C. of 160 hours.

(36) The product with TTI is then passed to node c, representing the warehouse. Upon accepting the goods from node b, user C measures the color of the TTI, confirming that the color of the TTI is lower than 0.23 O.D., representing a MRSSL at 4° C. of 128 hours. At this node, the TTI becomes exposed to the room temperature for an unknown period of time.

(37) The product with TTI is then passed to node d representing the second transporter that transports the goods from the warehouse to the supermarket store-room. Upon accepting the goods from company c, user D measures the color of the TTI, expecting to detect whether the color is lower than 0.26 O.D., representing a MRSSL at 4° C. of 109 hours. However, the reading shows the color of 0.29 O.D. which represents a MRSSL at 4° C. of 109 hours. This is because the TTI has been exposed to the room temperature for an unknown period of time that occurred at node c.

(38) The temperature abuse can now be easily correlated with company c since this company is delivering the product with TTI, the condition of which was in accordance with the standards until it reached node c and was found to exceed the maximal color at the supply chain between nodes c and d.

(39) The protocol may thus allow the receiving party to refuse accepting goods having shorter than determined minimal remaining standard shelf life at a standard temperature. Alternatively, the protocol may serve to find failure points in such a chill chain or allow pricing of goods with respect to their minimal remaining standard shelf life at a standard temperature.

Example 2

(40) In this example, the TTI used for demonstrating the monitoring and controlling of the chill chain using a handshake protocol in accordance with the present invention, is the Time Temperature Indicator developed in part by one inventor of the present invention and disclosed in WO 99/39197. The specific time variation of the TTI response at 2° C. is shown in FIG. 5B.

(41) In a simulation of the chill chain condition, the TTI is transferred from one person (node) to another in a way that none of them could know the time-temperature history of the TTI prior to the time point the TTI is received at the specific node. Each of the participants is equipped with the TTI response reading device of the present invention, calibrated to the specific TTI.

(42) The standard conditions of the specific chill chain determined for the experiment are as follows: Each party is entitled to refuse acceptance of the goods transported along the chill chain, if the remaining standard shelf life at 2° C. (MRSSL at 2° C.) is shorter than the minimal value, as depicted in Table 2.

(43) TABLE-US-00002 TABLE 2 Minimal remaining standard shelf life at 2° C. Remaining standard shelf life (hrs) Station Minimum Maximum Color (L*) a 500 49 b 458 57 c 412 64 d 335 72 e 225 78

(44) First experiment—the TTI is kept at a constant temperature of 2° C. all along the experiment.

(45) At the starting node a (a company that produces the product), the TTI associated with the product is charged at a temperature of 2° C., thus setting its “time zero”. At that moment, the TTI response (color) is measured (using the device of the present invention), confirming that the color of the TTI is higher than 49 L*, representing a MRSSL at 2° C. of 500 hours. The TTI is then allowed to pass to node b representing the first transporter that transports the goods from the producer to the first warehouse.

(46) At node b, upon accepting the goods from node a, the color of the TTI is measured, confirming that the color of the TTI is higher than 57 L*, representing a MRSSL at 2° C. of 458 hours. The TTI is then passed to node c representing the warehouse.

(47) At node c, upon accepting the goods from node b, the color of the TTI is measured, confirming that it is lower than 64 L*, representing a MRSSL at 2° C. of 412 hours. The TTI is then passed to node d representing the second transporter that transports the goods from the warehouse to the supermarket store-room.

(48) At node d, upon accepting the goods from node c, the color of the TTI is measured, confirming that it is lower than 72 L*, representing a MRSSL at 2° C. of 335 hours. The TTI is then passed to node e, representing the supermarket shelf.

(49) At node e, upon accepting the goods from node d, the color of the TTI is measured, confirming that it is lower than 78 L*, representing a MRSSL at 2° C. of 225 hours.

(50) It should be understood that the main differences between Examples 1 and 2 are in the direction of the change in color: in Example 1 the TTI color changes from light to dark, while in Example 2—from dark to light; and in that the TTI of Example 2 is chargeable and may be charged at the precise desired time.

(51) Second experiment of Example 2—the TTI is kept at a constant temperature of 4° C. all along the experiment, except for that in the warehouse, where the TTI is exposed to the room temperature for an unknown period of time.

(52) At node a, the TTI color is sensed, confirming that it is higher than 49 L*, representing a MRSSL at 2° C. of 500 hours. The TTI is then passed to node b representing the first transporter that transports the goods from the producer to the first warehouse.

(53) Upon accepting the goods from node a, user B at node b measures the color of the TTI, confirming that the color is higher than 57 L*, representing a MRSSL at 2° C. of 458 hours. The product with TTI is then passed to node c, representing the warehouse.

(54) At the warehouse (node c), upon accepting the goods from node b, the color of the TTI is measured, confirming that the color is higher than 64 L*, representing a MRSSL at 2° C. of 412 hours. Here, the TTI becomes exposed to the room temperature for an unknown period of time. The TTI is then passed to node d, representing the second transporter that transports the goods from the warehouse to the supermarket store-room.

(55) At the node d, upon accepting the goods from node c, the TTI is inspected to determine whether its color is higher than 72 L*, representing a MRSSL at 2° C. of 335 hours. The inspection shows the color to be of 84 L*, which corresponds to a MRSSL at 2° C. of only 155 hours. This is because at node c the TTI has been exposed to the room temperature for an unknown period of time. The temperature abuse can now be easily correlated with company c since this company is delivering a product with TTI that was in accordance with the standards until it reached node c and is found to exceed the maximal color when arrives to node d. Hence, here again, the protocol may allow the receiving party to refuse accepting goods having shorter than determined minimal remaining standard shelf life at a standard temperature, or alternatively, the protocol may serve to find failure points in such a chill chain or allow pricing of goods with respect to their minimal remaining standard shelf life at a standard temperature.

(56) One more example of the technique of the present invention consists of using a normal TTI that is characterized by one reference scale that is available only to the parties involved in the product chill chain supply. These parties are thus allowed for carrying out the quantitative assessment of the TTI using this reference scale. As for the end customer, he can solely obtain a digital YES/NO reference scale. The reference scale available to the parties of the chill chain supply line is made with a transparent region or hole in the middle, and can be placed manually and temporarily onto the TTI, such that the chill chain reference scale covers the customers scale during the inspection at the nodes of the chill chain.

(57) Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the invention as hereinbefore exemplified without departing from its scope as defined in and by the appended claims.