Patent ID: 8896701

Claim:
An active infrared sensor apparatus comprising: an imaging infrared sensor configured to output time-sequential images of a scene which includes a subject; a beam generator configured to generate a millimeter wave energy beam; and a processor configured to: store a first infrared image of the scene from the imaging infrared sensor in a memory, the first infrared image identifying an initial temperature distribution within the subject prior to illumination of the subject with the millimeter wave energy beam; cause the beam generator to illuminate the subject with the millimeter wave energy beam to thereby create an altered temperature distribution within the subject; obtain a second infrared image of the scene from the imaging infrared sensor, the second infrared image identifying the altered temperature distribution within the subject due to the millimeter wave energy beam; identify differences between the first and second infrared images to determine how the millimeter wave energy beam changes the temperature distribution within the subject; and cause the beam generator to stop illuminating the subject when a highest temperature change across the subject caused by the millimeter wave energy beam equals or exceeds a predetermined temperature change limit.