Remote indicating cumulative thermal exposure monitor and system for reading same

A remote indicating time-temperature integrating cumulative thermal exposure monitor for monitoring heat energy absorbed over time and indicating the degree of deterioration based on a time and temperature thermal deterioration profile of a perishable product that has a known time and temperature thermal deterioration profile and is prescribed to be maintained within a preferred storage temperature range, comprising:

• a thermally-conductive housing having a fluid sealed interior cavity, said housing formed of a material having thermal capacity and insulative properties which moderate heat energy conducted therethrough over time;
• an electrically conductive thermally-responsive member movably disposed in said interior cavity formed of a shape memory material selected from the group consisting of shape memory alloys, shape memory polymer composites, and shape memory materials coated or sheathed with insulating material or polymers that moderate the influx of heat energy into said thermally-responsive member, said thermally-responsive member having a phase transition temperature range encompassing at least the preferred storage temperature range and having a first shape at temperatures below said phase transition temperature range and gradually changing to a second shape at temperatures within or above the preferred storage temperature range;
• a radio frequency (RF) resonant circuit associated with said housing operatively coupled with said electrically conductive thermally-responsive member;
• said thermal capacity and insulative properties of said housing material and said shape memory material phase transition temperature range calibrated relative to one another to function in mutual cooperation such that said housing moderates heat energy conducted therethrough over time and said thermally-responsive member absorbs the heat energy and gradually assumes its said second shape upon absorption of heat energy over time to closely match the known time and temperature thermal deterioration profile of the perishable product;
• said electrically conductive thermally responsive member moves relative to said resonant circuit as it changes from its said first shape to said second shape and remains substantially in a position at which it was last moved, regardless of subsequent exposures of said shape memory material to lower temperatures;
• and
• a resonant frequency is induced in said resonant circuit in proportion to the change in heat absorbed by said thermally-responsive member to indicate the cumulative amount of heat energy absorbed in and above said preferred storage temperature range and whether, at any time, the temperature has been above said preferred storage temperature range for a period of time sufficient to cause any degree of deterioration based on the time and temperature thermal deterioration profile of the perishable product.