Patent Publication Number: US-7212100-B2

Title: Medical product expiration alerting

Description:
FIELD AND BACKGROUND OF THE INVENTION 
   The present invention relates, in general, to packaging, labeling and inventory management of medical products, and, in particular, relates to a new and useful medical product label used as an alert device, medical product packaging for a medical product using a label as an alert device, an expiration alert system and method for controlling medical product inventory based on expiration dates therefor. 
   It is well known that the packaging and labeling of medical products such as pharmaceuticals and medical devices are critical functions. As a result, many groups have great interest in this area besides the medical products companies and their customers and patients. For instance, groups such as the Healthcare Compliance Packaging Council (HCPC), the National Quality Forum (NQF) and others recognize the role that packaging plays in safeguarding healthcare. And of course, various government agencies, most notably the Federal Food and Drug Administration (FDA) have very stringent packaging regulations and enforcement. 
   Based on the critical nature and role that medical product packaging plays, there are a number of very important issues facing medical packagers as well as patients and consumers. One of these very real issues is the traceability of medical products. 
   Accordingly, there are considerable steps that are required to be taken to ensure packaging traceability. At this point, for example, only some manufacturers have affixed unit-of-use barcodes to hospital injectable drugs and/or IV solutions. Additionally, fraudulent products and drug counterfeiting are problems that also must be addressed. Internet drug sales contribute to this issue. The World Health Organization estimates that fraudulent drugs generate $32 billion dollars in annual earnings for drug counterfeiters. Thus, as can be imagined, tracking the pharmaceutical pedigree of these drug products continues to gain in importance. 
   There are also a number of other key concerns for medical product manufacturers and their customers and patients. Medical products sold and falsely represented as being “fresh”, “current” or “unexpired” after their expiration dates is one of these problems. 
   The diversion of products and ability to keep track of key locations in the supply chain of the medical products is also a chief concern. There are also other pure business concerns relating to the ability to properly track medical products. For example, supply chain management for the ability to properly track inventories, ensure proper supplies, and improve inventory management; inventory control as a key part of supply chain management to ensure tracking of inventory throughout the cycle; the ability to properly and efficiently handle medical product recalls which is a benefit not only to the public and manufacturer but to also to the government as well. As most in the field will agree, effective and efficient traceability of manufactured medical products will ease this complex process. 
   In an effort to meet the growing problem of medical product traceability, packaging technology has been changing in an effort to try to meet the needs of pharmaceutical and medical device manufacturers. 
   The use of bar codes on medical products has been one technology used to combat the traceability problem. Bar coding is currently the methodology for tracking unit dose packaging in pharmaceuticals. However, there are issues associated with using bar codes such as bar coding requires “line of sight” to be workable. It also requires multiple scans to track a drug or medical device from the manufacturer to the patient. Bar coding can even require multiple scans within a given facility to track progress to the patient bedside. The problems with wrinkled or damaged bar code labels can also make scanning difficult. 
   Additionally, in the United States, the lack of unit dose packaging of prescription drugs from the manufacturer results in bulk shipments with a much higher opportunity for diversion or misuse or counterfeiting. The implementation of unit dose with bar coding is one step that has been taken toward trying to improve traceability. 
   Other known issues relate to products containing components that are subject to degradation or are otherwise unsuitable for use after a set period of time. Accordingly, it is customary that these products contain an expiration date on the product packaging. 
   However, this information is usually contained in small print that is not readily obvious to the consumer, distributor or other owners or holders of the products. In addition the consumer and/or distributor are not alerted when product expiration is imminent. Proper product expiration alerting would be useful to have so that consumers and/or distributors may rotate products on shelving, return expired goods to manufacturers, discount the products prior to expiration or otherwise consume the products so that an adverse event relating to the patient, economics or other event can be avoided. 
   Additionally, those users or patients who are sight impaired or blind are significantly disadvantaged by printed expiration dating on the product packaging. 
   Accordingly, to date there has been no system, device or method for alerting a user as to the expiration of a medical product or for controlling medical product inventory and traceability based on expiration dates therefor. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a new and useful medical product label (used as an alert device), package, expiration alert system and method for controlling medical product inventory based on expiration dates therefor. 
   In one embodiment according to the present invention, the present invention is a system for monitoring a time sensitive medical product, the system comprising:
         a medical product;   a packaging containing the medical product;       

   at least one label associated with the packaging or the medical product, the at least one label comprising:
         (i) at least one permanent region having permanent indicia;   (ii) at least one transformable region having time sensitive indicia, the time sensitive indicia being non-detectable in a first state and detectable in a second state;   (iii) a micro-controller operatively connected to at least one of the at least one permanent region and the at least one transformable region, the micro-controller monitoring elapsed time and causing the at least one transformable region to change from the first state to the second state thereby revealing the time sensitive indicia in the second state; and   (iv) a power source operatively connected to the micro-controller.       

   The system according to the present invention has at least one transformable region that is irreversibly transformable. Additionally, the system further comprises a clock and a keypad operatively connected to the micro-controller. The keypad is optional and is used for inputting data to the micro-controller. In many examples, the data relates to an expiration date for the medical product wherein the expiration date is displayed in the at least one permanent region of the label. 
   The system also comprises an audio output device operatively connected to the micro-controller wherein the audio output device provides, emanates or outputs an audio signal when the at least one transformable region changes from the first state to the second state. 
   In certain embodiments according the present invention, the system further comprises a second transformable region operatively connected to the micro-controller. In these embodiments, the second transformable region can be used as a positive control relating to use of the medical product. Additionally, the system may further comprise a third transformable region operatively connected to the micro-controller wherein the third transformable region is used as a negative control relating to use of the medical product. Likewise, the second transformable region and the third transformable region can also display indicia. The indicia can include any combination of letters, characters, symbols, colors, etc. 
   In some embodiments according the present invention, the at least one transformable region, the second transformable region and the third transformable region comprise an electro-chromic material. In other embodiments, the at least one transformable region, the second transformable region and the third transformable region comprise a photo-chromic material or a thermo-chromic material respectively or any combination of these materials. 
   In accordance with the present invention, the medical product can be any type of health care related product, for instance, a drug, device or consumer product as specific examples, and especially any type of medical product that is time sensitive, i.e. has a limited shelf life. In preferred embodiments, the medical product is a drug eluting stent wherein the medical product further includes a stent delivery system. 
   Additionally, the packaging for the medical product can be in any desired form such as a bottle, box or pouch as just a few specific examples and in certain embodiments the packaging is in multiple sections, in one preferred embodiment, and comprises a box, an outer pouch, an inner pouch and a tray for the medical product. 
   More than one label or alert device in accordance with the present invention can be used for the medical product and/or its packaging. For example, a second label is included with the outer pouch and a third label is included with the inner pouch. 
   The present invention is also directed to a method for controlling inventory of a time sensitive medical product wherein the method comprising the steps of:
         providing packaging for the medical product;   configuring an expiration date for the medical product;   displaying the expiration date with the medical product in a visible manner on or within the packaging or on or within the medical product;   configuring a warning period for warning of an upcoming expiration for the medical product in advance of the expiration date;   monitoring elapsed time with the packaging or with the medical product after setting the expiration date for the medical product;   displaying a warning indicator on or within the packaging or on or within the medical product of the upcoming expiration for the medical product upon commencement of the warning period.       

   The method further comprises providing an audio signal from the packaging or from the medical product upon reaching the configured warning period. The audio signal is provided prior to expiration date for the medical product and/or on the expiration date for the medical product. Additionally, the method further comprises using a label (as an alert device) with the packaging or the medical product for controlling inventory of the medical product. 
   The label is used to set the expiration date and the warning period. The label is also used to display the expiration date and the warning indicator. Moreover, using the label, elapsed time is monitored after setting the expiration date. Upon reaching the expiration date, the label provides an audio signal signaling the upcoming expiration of the medical product and/or the actual expiration of the medical product. 
   The method further comprises using an irreversible transformable region on the label to display the warning indicator. Additionally, the method further comprises displaying the warning indicator in discrete sections in the irreversible transformable region wherein each discrete section of the warning indicator is displayed on each day of the warning period. Accordingly, the warning indicator can be displayed in discrete sections on respective sub-regions of the irreversible transformable region. 
   In certain embodiments, the warning indicator uses the word EXPIRED or a variant thereof as the warning indicator. And, in these embodiments, each character of the warning indicator is displayed on a corresponding sub-region of the irreversible transformable region on respective days of the warning period. 
   In some embodiments, a drug is the time sensitive medical product. In other embodiments, a device is used as the time sensitive medical product. In still other embodiments, the time sensitive medical product is a drug eluting stent, either alone or with a stent delivery system. 
   Another embodiment of the present invention is also directed to a method for controlling inventory of a time sensitive medical product, the method comprising the steps of:
         providing a medical product;   providing a packaging containing the medical product;   providing at least one label associated with the packaging or the medical product, the at least one label comprising:
           (i) at least one permanent region having permanent indicia;   (ii) at least one transformable region having time sensitive indicia, the time sensitive indicia being non-detectable in a first state and detectable in a second state;   (iii) a micro-controller operatively connected to at least one of the at least one permanent region and the at least one transformable region, the micro-controller monitoring elapsed time and causing the at least one transformable region to change from the first state to the second state thereby revealing the time sensitive indicia in the second state; and   (iv) a power source operatively connected to the micro-controller.   
           configuring an expiration date for the medical product and storing the expiration date in the micro-controller;   displaying the expiration date for the medical product in a visible manner on the label;   configuring a warning period in the micro-controller for warning of an upcoming expiration for the medical product in advance of the expiration date;   monitoring elapsed time with the micro-controller after setting the expiration date for the medical product;   displaying a warning indicator on the label of the upcoming expiration for the medical product upon commencement of the warning period.       

   The method further comprises providing an audio signal from the label upon reaching the configured warning period. The audio signal is provided prior to expiration date for the medical product and/or on expiration date for the medical product. The method also further comprises using an irreversible transformable region on the label to display the warning indicator. 
   Additionally, in certain embodiments, the method further comprises displaying the warning indicator in discrete sections in the irreversible transformable region wherein each discrete section of the warning indicator is displayed on each day of the warning period. Moreover, the method further comprises displaying the warning indicator in discrete sections on respective sub-regions of the irreversible transformable region. 
   As previously indicated, the word EXPIRED or a variant thereof can be used as the warning indicator. Additionally, each character of the warning indicator can be displayed on a corresponding sub-region of the irreversible transformable region on respective days of the warning period. 
   Moreover, in certain embodiments, a drug is used as the time sensitive medical product. In other embodiments, a device is used as the time sensitive medical product. In preferred embodiments, a drug eluting stent is used as the time sensitive medical product. And in other preferred embodiments, a stent delivery system together with the drug eluting stent is used as the time sensitive medical product. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may be understood by reference to the following description, taken in conjunction with the accompanying drawings in which: 
       FIGS. 1A–1H  illustrate a label for a medical product including a system and method for inventory control of the medical product; 
       FIGS. 2A–2C  illustrate the label and system and method for inventory control of  FIGS. 1A–1H  wherein the medical product is contained in packaging in the form of a box; 
       FIGS. 3A–3C  illustrate the label and system and method for inventory control of  FIGS. 1A–1H  wherein the medical product is contained in packaging in the form of a bottle; and 
       FIGS. 4A–4C  illustrate the label and system and method for inventory control of  FIGS. 1A–1H  wherein the medical product is contained in multiple section packaging for a drug eluting stent as part of a stent delivery system. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention is directed to a new and useful medical product label, package, expiration alert system and method for controlling medical product inventory based on expiration dates therefor. 
   The principles and operation of the medical product label, package, expiration alert system and method for controlling medical product inventory according to the present invention may be better understood with reference to the drawings and accompanying descriptions. 
   Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
   As best illustrated in  FIGS. 1A–1H , the present invention is an alert device depicted as a label, generally designated  100 , particularly useful for medical products ( FIGS. 2A–2C ,  3 A– 3 C and  4 A– 4 C), and particularly useful for time sensitive medical products, i.e. medical products that require an expiration date or have a finite shelf life after being manufactured. As defined herein, the term “medical product” means one or more drugs, pharmaceuticals, chemical compounds, biological agents, biological molecules, organisms, organs, tissue, cells or components thereof such as nucleic acids (i.e. RNA and DNA), proteins, peptides, amino acids, medical devices and their components, nutrition items such as food products, consumable items, consumer products, polymers (i.e. either natural or synthetic polymers) to include biodegradable and/or bioabsorbable polymers to include hydrogel polymers, any product useful for any therapeutic, diagnostic or healthful purpose or any product requiring an expiration date or specified period of use. 
   The present invention disclosed herein is directed to providing a visual and/or audible alert or signal contained as part of the packaging for the medical product or part of the medical product itself in order to notify the handlers and end users of the medial products that the medical product is nearing the end of its life cycle, period of use or expiry date. 
   The alert device  100  (label) has a body  105  having a thickness typically in the range of 0.1 to 0.8 mm (or any desired thickness) and having any width and length dimensions capable of being affixed to the medical product itself or the medical product packaging  50  or capable of being housed or contained in the medical product packaging  50 . As defined herein, the terms “medical device packaging”, “packaging” or “package” can be used interchangeably and mean any type of container or storage mechanism for the medical product. Some relevant examples of “medical device packaging”, “packaging” or “package” include any box, case, bottle, tray, container, pouch, bag, dish, tube, beaker, or the like to include any components associated therewith such as a top, cap, lid, stopper, flap, Tyvek, seal, fitting or the like. Some illustrative examples are shown in  FIGS. 2A–2C  (packaging  50  as a box  50   a ),  FIGS. 3A–3C  (packaging  50  as a bottle  50   b ) and  FIGS. 4A–4C  (multiple section packaging  50  for a drug eluting stent “DES”, such as the CYPHER® Sirolimus-eluting Coronary Stent as part of a stent delivery system “SDS”; described in greater detail later below). 
   When used as a label  100  affixed to the medical product or the packaging  50  of the medical product, the alert device  100  also includes an appropriate attachment system such as an adhesive backing, hook and loop fasteners, etc. (not shown) for securing the label  100  to a surface of the packaging  50 . The alert device  100  may be printed, applied to, or otherwise embedded in the packaging  50 , i.e. the primary and/or secondary product packaging or at the packaging associated with the case or lot level. 
   Label  100  can be partially made from technology marketed by Power Paper Ltd. (Petah Tikva, Israel) as partially described in U.S. Pat. No. 6,676,021 B1, which is incorporated herein by reference. Label  100  is formed with at least one permanent region thereon, generally designated  110 , for indicating permanent indicia such as an expiration date, period of use or the like. The permanent region  110  optionally includes a plurality of sub-regions  110   a – 110   j  in the examples where the permanent region  110  indicates an expiration date (in this example, four digits for the year, two digits for the month and two digits for the day wherein the year, month and day are separated by hyphens, i.e. 2005-09-30 indicating an expiration date of Sep. 30, 2005). 
   As will be described in better detail below, the permanent region  110 , such as the expiry notice or date  110   a – 110   j  in this example, of label  100 , is set through either programmed (hard coded) by the manufacturer to alert the end user of the expiration information associated with the medial product according to a predetermined, pre-set, non-modifiable time interval, or alternatively, the label  100  and permanent region  110 , such as the expiry notice or date  110   a – 110   j  in this example, is configured by the end user to notify themselves or their personnel according to their personalized or customized choice of time interval, for instance a time interval prior to the manufacturer&#39;s recommended expiry date in order to serve as a warning period alerting the user of the upcoming expiration date. 
   The alert device  100  also includes at least one transformation region, generally designated  140 , for displaying a warning indicator (for example, as shown, the at least one transformation region  140  can include a plurality of sub-regions indicated as  140   a – 140   g  in this example). In several embodiments of the present invention, the transformation region  140  has seven sub-regions  140   a – 140   g  for indicating time sensitive and relevant information or indicia in discrete sections such as each letter of the term “EXPIRED” or any like term indicating the end of recommended use period or product expiry including any variants of these indicia or terms to include abbreviations, etc. Micro-controller  150  can be programmed in any desired language for displaying the warning indicator in any language of choice selected by the end user (not limited to the English language, but rather, any language of a particular country, region or origin). Transformation region  140  and sub-regions  140   a – 140   g  are irreversibly transformable from a first state into a second state. The second state is clearly identifiable and readily discernable by any handler of the medical product packaging or end user as being different from the first state. 
   As shown in  FIGS. 1A–1H , by way of example, transformation sub-regions  140   a – 140   g  contain a warning indicator according to a respective letter of the word “EXPIRED” that are not visible to the naked eye in the first state and clearly visible and readily discernable when transformed to the second state.  FIG. 1A  illustrates all sub-ions  140   a – 140   g  in the first state (term “EXPIRED” is not visible) while  FIG. 1G  illustrates all sub-regions  140   a – 140   g  in the second state wherein the term “EXPIRED” is clearly indicated. 
   Additionally, as a control for ensuring proper functioning for the alert device (label)  100 , other transformable regions  142  and  144  respectively are optionally provided and used as reassurance and quality check of proper functioning for the alert device (label)  100 . As best illustrated in  FIGS. 1A–1H , transformable region  142  can be used as a positive control indicated as a symbol or message indicating proper functioning or non-expiration for the medical product, for example, a message such as “USE” and/or a green light symbol. Moreover, transformable region  144  can be used as a negative control as a symbol or message indicating improper functioning or expiration or termination of use period for the medical product, for example, a message such as “STOP” and/or a red stop sign symbol. 
   Likewise, similar to the functioning of transformation region  140  and sub-regions  140   a – 140   g , transformation regions  142  and  144  respectively are also irreversibly transformable from a first state into a second state wherein the second state is clearly identifiable and readily discernable by any handler of the medical product packaging or end user as being different from the first state. 
   Thus, the transformation region  140 , sub-regions  140   a – 140   g , and other transformation regions  142  and  144  (control regions  142  and  144 ) can transform from a non-detectable region (first state) into a detectable region, e.g., colored region (second state), or from a region having one or no color (first state) into a region having another, readily distinguishable, color (second state), all as is further described and specifically exemplified hereinbelow. 
   The alerting device may be a visual or audible indicator such as a timer that shows decreasing intervals of time before the expiry date is reached or audible speech or other sounds that signal decreasing intervals of time before the expiry date is reached. 
   According to one embodiment of the present invention, each of the transformation regions  140  (including sub-regions  140   a – 140   g ), positive control region  142  and negative control region  144  include an electro-chromic substance, which may be applied in different desirable patterns, and which is capable of irreversibly changing its color as a response to an electrical potential. Such electrical potential is controlled by micro-controller  150  and can, for example, be provided, from an integrated power source  160  operatively connected to the micro-controller  150 . Accordingly, the activating of the power source  160  (by micro-controller  150 ) to exert the electrical potential to each of the transformation regions  140   a – 140   g ,  142  and  144 , results in irreversible change in color of the electro-chromic substance in each of the transformation regions  140   a – 140   g ,  142  and  144 . 
   Examples of electro-chromic substances suitable for use with the label  100  of the present invention include, but are not limited to, Indium-Tin-Oxide and Indium-Antimony-Tin-Oxide. In one embodiment of the invention, the transformation regions  140   a – 140   g ,  142  and  144  include the electro-chromic substance and encodes unique data e.g., a code of numbers or an alphanumeric code, (in this case, the word “EXPIRED” and positive and negative controls respectively which become irreversibly visible to the packaging handler or end user when the electro-chromic substance changes its state or color as a response to the electrical potential. 
   Micro-controller  150  is operatively connected to the permanent region  110  (including the permanent sub-regions  110   a – 110   j ), the transformation region  140  (including transformation sub-regions  140   a – 140   g ), positive control transformation region  142  and negative control transformation region  144 . The micro-controller provides a respective signal to each of the permanent region  110  (including the permanent sub-regions  110   a – 110   j ), the transformation region  140  (including transformation sub-regions  140   a – 140   g ), positive control transformation region  142  and negative control transformation region  144 . The signal provided by the micro-controller  150  to the permanent region  110  (including the permanent sub-regions  110   a – 110   j ), the transformation region  140  (including transformation sub-regions  140   a – 140   g ), positive control transformation region  142  and negative control transformation region  144  can be any type of appropriate signal for activating or irreversibly changing the state of these various regions. Accordingly, the signal sent by the micro-controller is either based on an electrical signal such as current (AC or DC), electrical potential, voltage, impedance, magnetic, electromagnetic as relevant examples. 
   The micro-controller  150  comprises a logic circuit which can be based on any type of appropriate logic software or ASIC for controlling the permanent region  110  (including the permanent sub-regions  110   a – 110   j ), the transformation region  140  (including transformation sub-regions  140   a – 140   g ), positive control transformation region  142  and negative control transformation region  144 . 
   Additionally, a keypad  180  is operatively connect to and associated with the micro-controller  150  for performing relevant programming of the data necessary for the permanent region  110  (including the permanent sub-regions  110   a – 110   j ), i.e. the expiration date as eight characters separated by hyphens, the transformation region  140  (including transformation sub-regions  140   a – 140   g ), i.e. the term “EXPIRED”, the positive control transformation region  142 , i.e. green light symbol and term “USE” and negative control transformation region  144 , i.e. red stop sign symbol and term “STOP”. Accordingly, in these embodiments according to the present invention, the manufacturer or the end user has the ability to program the expiration date into permanent region  110  (including the permanent sub-regions  110   a – 110   j ) using the keypad  180 . It may be desirable for the manufacturer to permanently set the expiration date in a permanently locked (tamper proof) state in permanent region  110  at the manufacturing site thereby eliminating any possibility of tampering or adjusting of the expiration date by another person. 
   Additionally, an optional clock  170  (which can be a digital clock) is operatively connected to micro-controller  150  for purposes such as setting or configuring the indicia in permanent region  110 , i.e. the eight digit expiration date (not including hyphens for sub-regions  110   a – 110   j ), and for outputting continuous time readings in real time for the monitoring the elapsing time period (through micro-controller  150 ) for transformation regions  140  including  140   a – 140   g , and control regions  142  and  144  respectively. Accordingly, micro-controller  150  continuously monitors the real time output from digital clock  170  through continuous readings and activates irreversible regions  140  (including sub-regions  140   a – 140   g ), and irreversible control regions  142  and  144  respectively at the designated pre-determined times. Power source  160  also provides power to digital clock  170  through micro-controller  150 . 
   An audio output device  190  for outputting an audible signal  195  such as an alarm which can be in the form of any desired tone or tones or audible warning statements in any desired language which can all be programmed into the logic circuit or software of micro-controller  150 , for example, when the last sub-region  140   g  has been achieved and all sub-regions  140   a – 140   g  has been filled, meaning the term “EXPIRED” is reflected in these sub-regions based on the lapse of the pre-determined, set expiration period. The audio signal is provided at any time(s) prior to the expiration date for the medical product and/or on the expiration date for the medical product, i.e. in advance of the expiration date and/or at any desired times during the warning period, and/or on the expiration date for the medical product. 
   The warning system of the present invention is both visual and audible (if desired). Visual warning is provided through irreversible region  140  and sub-regions  140   a – 140   g  of the alert device  100 . These sub-regions  140   a – 140   g  may be a visual indicator such as a timer that shows decreasing intervals of time before the expiry date is reached. Moreover, alarm  190  provides warning  195  in the form of an audible signal or audible speech or other sounds that signal decreasing intervals of time before the expiry date is reached. 
   One appropriate example for use of the alert device  100  in accordance with present invention is a drug eluting stent (DES), such as the CYPHER® Sirolimus-eluting Coronary Stent as part of a stent delivery system (SDS), generally designated  50   g , in its multiple section packaging  50  as best shown in  FIGS. 4A–4C . In this example, the medical product (CYPHER® Sirolimus-eluting Coronary Stent)  50   g  has an FDA mandated expiration date period, for instance, 90 days from date of manufacture. Accordingly, alert device  100  is associated with (affixed to or adhered to) all key sections of the multiple section packaging  50  in accordance with this example. For instance, alert device  100  is affixed to the box  50   c  as shown. Box  50   c  contains sterile packaging and maintains a sterile environment by using an outer pouch (outer foil pouch)  50   d  with a tearable section (indicated by dashed horizontal lines across the top portion of outer pouch  50   d . The outer pouch  50   d  also includes a second alert device  100  affixed on a surface thereof. An inner pouch  50   e  is removable housed or contained within outer pouch  50   d . Inner pouch  50   e  is also a sealed pouch maintaining a sterile environment for tray  50   f  and medical product  50   g  (DES and SDS in this example) which is protected and held in place by tray  50   f . The inner pouch  50   e  also includes a third alert device  100  affixed on a surface thereof (not shown—hidden behind second alert device  100  on outer pouch  50   d ). Thus, in this example, three separate alert devices  100  are used on each key section of the multiple section packaging  50  associated with this particular product  50   g . Each of the alert devices  100  are programmed with the same expiration date  110  through use of the micro-controller  150  associated with each alert device  100  in the manner described previously above. 
   Furthermore, the present invention is also a method for controlling inventory of medical product  50   g . The inventory of medical product  50   g  is controlled according its expiration date through permanent region  110  and irreversible transformable region  140  and its sub-regions  140   a – 140   g . In this example, the irreversible region  140  and its sub-regions  140   a – 140   g  serve as a visual indicator that counts down the remaining week (7 day period) before expiration by forming the word “expired” through a thin, digital display or through the appearance of letters via a chemical (e.g. oxidative) process is as follows:
     E (7 days before expiry)   EX (6 days before expiry)   EXP (5 days before expiry)   EXPI (4 days before expiry)   EXPIR (3 days before expiry)   EXPIRE (2 days before expiry)   EXPIRED (Day of expiry)   

   Accordingly, the alert device  100  uses an algorithm that is contained in the micro-controller  150  as follows:
 
Time exp −Warning Period total =Time warn start 
 
   In this example, Time exp  (Sep. 30, 2005)−Warning Period total  (7 days total to expiry)=Time warn start  (Sep. 24, 2005). 
   Upon final manufacturing of the medical product  50   g , the expiration date (reflected in permanent region  110 ) is keyed into the software program and algorithm of micro-controller  150  through use of the keypad  180 . Accordingly, the manufacturer programs this expiration date into the software of the micro-controller such that the expiration date is visually indicated on the label  100  of the packaging. When multiple section packaging is used that require separate labels  100  for each key section of the packaging  50  (such as shown in  FIGS. 4A–4C ), the same expiration date is programmed into the micro-controller  150  for each label  100 . 
   Additionally, alert device or label  100  commences a series of consecutive visual indicators by using irreversible sub-regions  140   a – 140   g  on consecutive days according to a formula (contained in the micro-controller  150 ) wherein each irreversible sub-regions  140   a – 140   g  indicates the appropriate warning based on the number of days prior Expiry date. Thus, a separate sub-region  140   a – 140   g  is visible for each day prior to Expiry date beginning on the date the warning visual should start, i.e. Time warn start  (Sep. 24, 2005 in the example shown) with a visual indicator shown in sub-region  140   a . Each subsequent day, will cause another sub-region  140   b ,  140   c , etc. to show its appropriate visual indicator on that designated day prior to Expiry date. 
   Accordingly, in this example, on Sep. 24, 2005, irreversible sub-region  140   a  will indicate “E” seven days prior to Expiry; irreversible sub-region  140   b  will indicate “EX” six days prior to Expiry; irreversible sub-region  140   c  will indicate “EXP” five days prior to Expiry; irreversible sub-region  140   d  will indicate “EXPI” four days prior to Expiry; irreversible sub-region  140   e  will indicate “EXPIR” three days prior to Expiry; irreversible sub-region  140   f  will indicate “EXPIRE” two days prior to Expiry; and irreversible sub-region  140   g  will indicate “EXPIRED” on the day of Expiry. 
   Additionally, the audio alarm  190  (optional) sounds an audio signal or audio expiration message  195  which can be either a specific audible tone, audible pulse tone (such as series of beeps) or audible verbal message or statement (in any desired language programmed into the micro-controller  150 ) that medical product (in this example DES  50   g ) has reached its expiration date. 
   In general, handlers and end users, for example surgical nurses and physicians, of this type of medical product, i.e. stent products or DES products, are commonly known to select their stent products or DES products, from their storage rooms and inventory shelving without referring to expiration dates marked or indicated on the packaging. Accordingly, stent products or DES products or other types of medical products that actually have longer remaining expiration periods are selected for use first, whereas those medical products that are closer to expiration are often not chosen or selected due to simple oversight by the product handlers and end users. Accordingly, the alert device or label  100  in accordance with the present invention avoids this problem and ensures that the inventory of medical product is properly managed, i.e. by ensuring each product visibly reflects remaining days prior to expiration through the EXPIRED nomenclature and methodology outlined above. Thus, when using the alert device or label  100  as part of an overall inventory management system, the product handler or end user selects only those medical products that have the earliest expiration date reflected through visual indicators shown in irreversible sub-regions  140   a – 140   g . In this example, DES product  50   g , can be managed by visually identifying those products closest to their expiration date (reflected in permanent region  110 ) and reinforced and visually alerted as a visual indicator by identifying how many of the irreversible sub-regions  140   a – 140   g  have reversed their color or visual scheme. 
   Accordingly, the product handler or end user will first identify only that medical product  50   g  which has one or more irreversible sub-regions  140   a – 140   g  that have undergone color or visual scheme change. In order of priority, the handler or end user will select medical product  50   g  according to the following prioritized scheme:
     EXPIRED (Day of expiry)   EXPIRE (2 days before expiry)   EXPIR (3 days before expiry)   EXPI (4 days before expiry)   EXP (5 days before expiry)   EX (6 days before expiry)   E (7 days before expiry)   

   In the event none of the medical product  50   g  in inventory does not have any irreversible sub-regions  140   a – 140   g  with a color change, i.e. Time warn start  has not yet been initiated due to the present date or date of use of the medical product  50   g  being more than 7 days prior to its expiry date, the handler or end user will draw medical product  50   g  from inventory for use based on the earliest expiry date reflected in permanent region  110 . 
   According to another embodiment of the present invention permanent region  110  (including the permanent sub-regions  110   a – 110   j ), the transformation region  140  (including transformation sub-regions  140   a – 140   g ), positive control transformation region  142  and negative control transformation region  144  include a heatable element which is capable of irreversibly changing an appearance of each of these regions when heated, by for example, inflicting burn marks thereon. The heatable element contained within permanent region  110  (including the permanent sub-regions  110   a – 110   j ), the transformation region  140  (including transformation sub-regions  140   a – 140   g ), positive control transformation region  142  and negative control transformation region  144  can be, for example, a heatable resistor (heating wire), a heatable conductor or a heatable semiconductor, e.g., semiconductor junction. Again, micro-controller  150  controls activation of the heatable element in each of the regions through the integrated power source  160  such that activating power source  160  to heat the heatable element results in irreversible change in appearance of permanent region  110  (including the permanent sub-regions  110   a – 110   j ), the transformation region  140  (including transformation sub-regions  140   a – 140   g ), positive control transformation region  142  and negative control transformation region  144 . Similar to the above-outlined embodiment, according to a preferred configuration, the heatable element encodes the unique data which becomes irreversibly visible to the packaging handler or end user when heatable element is activated or heated upon command of micro-controller  150 . 
   According to a preferred embodiment of the present invention the integrated power source  160  includes a capacitor which can be discharged, thereby providing high voltage which is required for implementing some of the embodiments of the present invention as herein described. Such a capacitor can be charged by an integrated battery (electrochemical cell) or in other cases, by an inducible power source, such as, but not limited to, a radiofrequency responsive coil or a piezoelectric component which is mechanically inducible. Direct power supply can also be effected by any of the above power sources, as well as AC power, when combined with a DC to AC converter. 
   A highly suitable power source for use with the alert device  100  of the present invention includes a flexible thin layer open liquid state electrochemical cell. The structure, manufacture and integration into electronic applications of such a flexible thin layer open liquid state electrochemical cell are described in detail in U.S. Pat. Nos. 5,652,043; 5,811,204 and 5,897,522, all to Nitzan, which are incorporated by reference as if fully set forth herein. 
   Briefly, the cell described in these U.S. Patents is an open liquid state electrochemical cell which can be used as a primary or rechargeable power supply for various miniaturized and portable electrically powered devices of compact design. The cell comprises a first layer of insoluble negative pole, a second layer of insoluble positive pole and a third layer of aqueous electrolyte, the third layer being disposed between the first and second layers and including (a) a deliquescent material for keeping the open cell wet at all times; (b) an electroactive soluble material for obtaining required ionic conductivity; and, (c) a water soluble polymer for obtaining a required viscosity for adhering the first and second layers to the first layer. Several preferred embodiments of the battery disclosed in U.S. Pat. No. 5,652,043 include (i) engaging the electrolyte layer in a porous substance, such as, but not limited to, a filter paper, a plastic membrane, a cellulose membrane and a cloth; (ii) having the first layer of insoluble positive pole include manganese-dioxide powder and the second layer of insoluble negative pole include zinc powder; (iii) having the first layer of insoluble negative pole and/or the second layer of insoluble positive pole further include carbon powder; (iv) selecting the electroactive soluble from zinc-chloride, zinc-bromide, zinc-fluoride and potassium-hydroxide; (v) having the first layer of insoluble negative pole include silver-oxide powder and the second layer of insoluble positive pole include zinc powder and the electroactive soluble material is potassium-hydroxide; (vi) having the first layer of insoluble negative pole include cadmium powder and the second layer of insoluble positive pole include nickel-oxide powder and selecting the electroactive soluble material to be potassium-hydroxide; (vii) having the first layer of insoluble negative pole include iron powder and the second layer of insoluble positive pole include nickel-oxide powder and selecting the electroactive soluble material to be potassium-hydroxide; (viii) having the first layer of insoluble negative pole and the second layer of insoluble positive pole include lead-oxide powder, the cell is charged by voltage applied to the poles and the electroactive soluble material is selected in this case to be sulfuric-acid; (ix) the deliquescent material and the electroactive soluble material can be the same material such as zinc-chloride, zinc-bromide, zinc-fluoride and potassium-hydroxide; (x) the deliquescent material is selected from the group consisting of calcium-chloride, calcium-bromide, potassiumbiphosphate and potassium-acetate; (xi) the water soluble polymer can be polyvinylalcohol, poliacrylamide, polyacrylic acid, polyvinylpyrolidone, polyethylenoxide, agar, agarose, starch, hydroxyethylcellulose and combinations and copolymers thereof; (xii) the water soluble polymer and the deliquescent material can be the same material such as dextrane, dextranesulfate and combinations and copolymers thereof. The cell described in these U.S. patents preferably includes terminals, each of the terminals being in electrical contact with one of the first and second pole layers. Such terminals can be made, for example, of graphite or a metal, such as iron, nickel, titanium, copper, stainless steel and mixtures thereof. The terminals can be applied to the cell and the entire cell can be manufactured by a suitable printing technology such as, but not limited to, silk print, offset print, jet printing, lamination, materials evaporation or powder dispersion. At least one carbon or graphite based conductive layer can be employed with the cell for improving the electronic conductivity of at least one of the first and second pole layers. Preferred configurations for power source  160  of the alert device  100  according to the present invention involve those combinations which are devoid of poisonous compounds. 
   According to another embodiment of the present invention irreversible region  140  and sub-regions  140   a – 140   g  include a photo-chromic substance which is capable of irreversibly changing its color as a response to lighting in a predefined wavelength, e.g., the visible range and/or ultraviolet radiation. Examples of photo-chromic substances suitable for use with alert device  100  of the present invention include Oxazine and Naphthopyran. Suitable radiation sources for activating the photo-chromic substance include sunlight, an ultraviolet light source, and any other artificial light source in a suitable wavelength range. The photo-chromic substance preferably encodes unique data on the alert device  100  (label) which becomes irreversibly visible to the medical product handler or end user when the photo-chromic substance changes its color as a response to lighting. A removable light impermeable cover can be used to protect the alert device  100  from light exposure prior to use. 
   According to another embodiment of the present invention irreversible region  140  and irreversible sub-regions  140   a – 140   g  of alert device  100  include a thermo-chromic substance which is capable of irreversibly changing its color as a response to external heating. Examples of thermo-chromic substances suitable for use with the label  100  of the present invention include M 2  HgI 4 , where M is Ag(I) or Cu(I). Suitable radiation sources for activating the thermo-chromic substance include sunlight, an infrared light source, and any other heat source. The thermo-chromic substance preferably encodes unique data which becomes irreversibly visible to medical product handler or end user when the electro-chromic substance changes its color as a response to external heating. 
   Additionally, any relevant electro-chromic, thermo-chromic and photo-chromic substances can be used with the present invention. The use of such substances and of heatable elements which may inflict burns according to the present invention provides the alert device  100  of the present invention with a highly effective means for providing visual warning of product expiration and method for inventory control. 
   The label  100  together with any time sensitive medical product and the packaging  50  therefor comprise a useful system for monitoring shelf life and elapsed time prior to expiration of the medical product and alerting the end user of an upcoming expiration according to a warning period in advance of the expiration date and/or at any desired times during the warning period, and/or on the expiration date for the medical product. 
   The alert device  100  and system and method for managing inventory for medical product is particularly cost effective especially given the high cost of goods usually associated with products such as medical devices and prescription medications, over the counter non-prescription consumer goods and packaged foods. 
   Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. 
   Inasmuch as the foregoing specification comprises preferred embodiments of the invention, it is understood that variations and modifications may be made herein, in accordance with the inventive principles disclosed, without departing from the scope of the invention. 
   While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will now occur to those skilled in the art without departing from the invention. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.