Patent Publication Number: US-2013227971-A1

Title: Wireless food safety monitor system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to Provisional Patent Application No. 61/606,184 filed Mar. 1, 2012, and is incorporated herein as set forth in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention is directed to a device for monitoring temperature within a refrigerator, indicating to a user that the food has entered the danger zone for refrigerated foods, and more particularly, for continuously monitoring the conditions within the refrigerator and notifying a remote user of the status of the conditions within the refrigerator. 
     In this day and age, refrigerators are found in restaurants, places of work, produce stores and the like. Almost all foods are now stored in a refrigerator at one time or another. 
     However, refrigerators are subject to breakage, brown-outs, black-outs, and even improper closing providing unexpected rises in temperature over different periods of time. Even temporary loss of power in a refrigerator may lead to damage of foods contained therein. 
     As a result, the Food and Drug Administration (“FDA”) has determined a “temperature danger zone” of time temperature exposure for foods. The FDA has determined that whenever the temperature of a food subject to spoilage falls between 41° F. and 135° F. (5° C. and 57° C.) the food is within the “temperature danger zone”. The FDA has also set forth guidelines that foods cannot remain for more than four hours in the danger zone before they are no longer safe for consumption. A refrigerator must be continuously working properly for the temperature of its contents to be maintained outside the temperature danger zone. 
     In situations where the owner/operator or staff is away from the refrigerator, such as during a busy work day, when the restaurant is closed, or during brown-outs or black-outs, the operator of the refrigerator can only guess, if they are aware at all, as to whether or not danger zone conditions have been experienced by the food within the refrigerator. 
     One instrument for solving this issue is the inventor&#39;s refrigerated food safety monitor, as known from U.S. Pat. No. 7,360,369 which describes a food refrigeration monitor, including a thermometer and a clock for determining when the thermometer measures a temperature above a predetermined temperature corresponding to food spoilage. If the measured time is greater than a predetermined time value, an alarm is sounded. This device has been satisfactory, however it suffers from the disadvantage, that one must open the refrigerator in order to determine the current status of the time temperature clock, thus increasing the exposure of the refrigerator&#39;s contents to danger zone inducing conditions, and if one is away from the refrigerator, the alarm cannot be monitored. 
     Accordingly, a device which overcomes the shortcomings of the prior art is desired. 
     SUMMARY OF THE INVENTION 
     A wireless system includes food refrigeration monitor having a thermometer for measuring the temperature within a refrigerator and a clock for measuring the time during which the thermometer measures a temperature of the ambient environment. The monitor also determines a time during which the temperature is above a predetermined value. The monitor provides an output to a transceiver and sends one of a temperature signal at predetermined time intervals, and an alarm signal when an accumulated time value exceeds a predetermined value. A remote monitor includes a transceiver for receiving signals from the time temperature monitor and storing temperature data as a time stamped entry, the remote monitor providing an output to a cellular phone transceiver for transmitting the data received from the monitoring unit to a remote device. 
     In one embodiment of the invention, the remote monitor polls the food refrigeration monitor to determine current conditions within the refrigerator. The food refrigeration monitor undergoes the same conditions as the food, so the user may check the food temperature within the refrigerator at any time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing in which: 
         FIG. 1  is a schematic diagram of a system for monitoring food temperature in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made to  FIG. 1  which shows a wireless food safety monitor system, generally indicated as  100 , constructed in accordance with the invention. Wireless food safety monitor system  100  includes a sensing unit, generally indicated as  10 , which is disposed within the refrigerator to be monitored. Wireless food safety monitor system  100  also includes a receiving station  200  disposed locally to the refrigerator (within the same facility or at least within wireless communication range of sensing unit  10 ), but outside of the refrigerator and is in communication with sensing unit  10  as well as a portable communication device. 
     Sensing unit  10  includes a time temperature sensor  12 . Time temperature sensor  12  such as that disclosed in Applicant&#39;s U.S. Pat. No. 7,360,369, which is incorporated herein in its entirety, includes a thermometer  13  encased in a housing for mimicking a temperature experienced by the food in the same environment as sensing unit  10  to measure the temperature of the food within the refrigerator, to provide a temperature output. In a preferred, but non-limiting example, sensor  12  may include a clock  15  for measuring time as known in the art. 
     Thermometer  12  continuously samples temperature within a refrigerator and outputs the measured temperature value. The clock  15  is a time interval clock which receives the temperature value from thermometer  13  and counts a time interval in response to the temperature sensed by the thermometer  13  of sensor  12  being above a predetermined temperature, such as 41° corresponding to the “temperature danger zone”. In this way a total time of temperature exceeding the predetermined temperature as sensed by sensor  12  is counted. Sensor  12  provides a temperature and/or a time temperature output to a microcontroller  14 . 
     Microcontroller  14  may also have a clock thereon as known in the art and may poll sensor  12  for its temperature data, or time temperature data at predetermined intervals, such as every ten minutes, every half hour or some appropriate interval for monitoring changes in temperature within the refrigerator environment. Microcontroller  14  also determines whether the time temperature value monitored by sensor  12  has exceeded a predetermined value indicating that the temperature has been in the “temperature danger zone” for a sufficient time to indicate potential or actual food spoilage; i.e., in time to provide a preemptive warning, or to indicate a temperature violation. As a function of such determination, microcontroller  14  outputs a report signal to a transceiver  16  which is coupled to an antenna  18  to broadcast an alarm condition indicative either that spoilage may have occurred, or may occur if preventive action is not taken. 
     In other embodiments of the invention, microcontroller  14  may also report the monitored temperature at predetermined time intervals to transceiver  16  causing the temperature data to be broadcast by antenna  18  on a periodic basis. In one non-limiting exemplary embodiment, antenna  18  may be a radio frequency (RF) module, but may be any antenna capable of communicating directly with other devices, including receiving station  200  or known portable devices. 
     Sensor  12 , microcontroller  14  and transceiver  16  are low voltage devices which are run by battery from a voltage regulated power source  20 . 
     The signal produced by antenna  18  is a low power signal which is transmitted to receiving station  200 , a pager, or other devices. Accordingly, a receiving station  200  is placed in the proximity of sensor  10 , but outside of the refrigerator environment (the broadcast area). Receiving station  100  receives the signal from antenna  18 , processes the signal as discussed below, and then transmits a report or alarm to one or more addressed mobile device, (not shown) such as a pager, tablet, or cell phone, carried by a person interested in the condition of the refrigerator. 
     More specifically, receiving station  200  includes a microcontroller and database  202 . In a preferred non-limiting embodiment, the database and microcontroller are formed as a single unit  202 . However, it is well understood in the art that a memory chip, separate from the microcontroller chip, may be used without departing from the spirit and scope of the invention. Microcontroller  202  is coupled to an antenna  204  by a receiver  206  for receiving the signals produced by antenna  18 . Microcontroller  202  may also communicate with other devices by an Internet connection at Internet port  209 . 
     Microcontroller  202  also receives a clock signal from an oscillator  208  as well as a real time signal from real time clock  210 . Microcontroller  202 , using these signals, may calculate a lapsed time as well as actual time in order to determine intervals and time stamps for monitored events. 
     Receiving station  200  also outputs data and messages to remote communication devices such as telephones, tablet computers, pagers, smart phones, laptops or the like. These remote devices may or may not be at the facility or in situ with the refrigerator being monitored, but utilizing system  100  allows continual monitoring by staff without the need to be continually at the facility with the refrigerator. Accordingly, microcontroller  202 , by way of non-limiting example, is operatively coupled to a GSM module  212  or DCMA or any other type of cellular signal under the control of a subscriber identity module (SIM) chip or card as known in the art. A voltage regulator  216  coupled to power supply and battery charger  222  powers GSM module  212  which outputs an address signal across antenna  213  for broadcast to the desired remote device. 
     The components of receiving station  200  may be portable or fixed and as a result are powered by a power supply and battery charger  222  which may receive power either from batteries  226  such as lithium ion cells or an AC wall plug  224 . In a preferred, non-limiting embodiment, power supply  222  operates on a 3 volt to 9 volt input and produces 3 to 4.7 volts which may be converted by a voltage regulator  228  to a lower voltage for powering either microcontroller  202  or receiver  206 . 
     Visual indicators such as light emitting diodes  220  are connected and powered by microcontroller  202 . Light emitting diodes  220  controlled by microcontroller  202 , may be of two or more colors to indicate a status such that one color such as green may indicate transmission of data from receiving station  200 , another color such as amber may indicate the reception of data, and a third color such as red for a third light indicating diode  220  may indicate temperature violation. 
     During operation, in one exemplary, but non-limiting embodiment, microcontroller  202  is passive and receives either an alert or an alarm signal or the periodic temperature signal from monitor  10  at antenna  204 . Microcontroller  202  then date stamps the data utilizing an input from real time clock  210 , stores the data or outputs a status signal by triggering an output to GSM module  212  causing a broadcast of a signal across antenna  213  to a remote device. 
     For example, microcontroller  202  may be programmed, in one non-limiting example to always forward the report of a danger zone condition, such as temperature above a predetermined value such as 41° F. Microcontroller  202  may also always transmit the alarm corresponding to a determination of spoilage condition by monitor  10 , and the receipt of a spoilage signal at receiving station  200 . 
     On the other hand, microcontroller  202  may make use of time intervals as determined utilizing oscillator inputs from oscillator  208  to determine predetermined time intervals to trigger the output of an information data signal to GSM module  212  or any type of cellular signal or internet communication for transmittal across an antenna  213  even when there is no alarm condition. The information data signal may be the current temperature as determined by monitor  10 , and a real time stamp. Microcontroller  202  may store a number of received temperatures, date and time stamp each as received, and then transmit the stored temperatures, at predetermined intervals, as a summary report. 
     It also should be understood, that microcontroller  202  may be an active element sending polling signals to monitor  10  causing microcontroller  14  to request information from sensor  12  to then be transmitted back to receiving station  200 . It should also be understood that the GSM module  212  or CDMA or cellular signal or internet under the control SIM  214  or other microprocessor can be called by a remote device causing microcontroller  202 , in response to a prompt, personal identification number, or other code from the remote device to dump the data stored in microcontroller  202  as a report to the remote device or poll monitor  10  to obtain a current status of the refrigerator. 
     It should also be well understood, that the functionality of system  100  may be split to varying degrees between receiving station  200  and monitor  10 . By way of example, microcontroller  14  may be “dumbed down” or clock  15  of sensor  12  may be removed because microcontroller  202  may poll monitor  10  at predetermined intervals to determine the temperature and then utilize oscillator  208  as the clock to determine a total elapsed time at which the temperature sensed at sensor  12  was in the danger zone. As a result, almost all of the functionality may be moved to the receiving station  200 . 
     By providing an elapsed time triggered monitor, capable of reporting to a receiving station which is capable of both storing data, or immediately reporting conditions to a remote device, a simple mechanism for allowing a user to recognize the proper operation of a refrigerator without the need to be in the same physical location as the refrigerator is provided. Most importantly, the device provides a quick, simple, automated way of determining in real time whether food contained within the refrigerator is unsafe, whether being physically monitored by the operator of the refrigerator or not, thus decreasing the risk of food poisoning, food spoilage, waste or the like. 
     Thus, while there have been shown, described and pointed out, novel features of the present invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the disclosed invention may be made by those skilled in the art without departing from the spirit and scope of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.