Patent ID: 8619507

Claim:
A stimulus-indicating device comprising: a first compartment; a second compartment; a constricting portion connecting said first compartment and said second compartment; an upper layer covering both an upper portion of said first compartment and an upper portion of said second compartment; a backing layer covering both a bottom portion of said first compartment and a bottom portion of said second compartment; a stimulus sensitive gel contained in said first compartment and said second compartment that is capable of shrinking in volume in response to exposure to a predetermined stimulus, wherein at least a portion of said stimulus sensitive gel is capable of moving out of said first compartment and is capable of moving through said constricting portion and is capable of moving into said second compartment in response to exposure to the predetermined stimulus; an indicator spot positioned in said first compartment; and a display portion positioned in said upper layer and positioned above said indicator spot, through which a color change can be seen in said first compartment after said stimulus sensitive gel shrinks in response to exposure to the predetermined stimulus and reveals a portion of said indicator spot, wherein said constricting portion is capable of permanently preventing said portion of said stimulus sensitive gel that moved out of said first compartment into said second compartment, from moving back into said first compartment and recovering said portion of said indicator spot visible through said display portion when the predetermined stimulus has been removed.