Infrared Impulse Spectroscopy for Inclusion-Independent Chemical Imaging

The patent applies periodic action by using pulsed infrared illumination instead of continuous illumination. The pulse duration is specifically controlled to be shorter than the thermal diffusion time constant, creating periodic thermal excitation that allows heat to remain localized to the inclusion rather than diffusing to surrounding areas. This periodic pulsed action enables the signal to depend on the absorptivity and concentration of the analyte rather than inclusion size, resolving the contradiction between acquisition speed and measurement precision.

The patent applies preliminary action by performing rapid sequential sampling at multiple time points immediately following the infrared pulse, capturing the thermal response before significant heat diffusion occurs. By collecting multiple time-resolved measurements during the brief thermal event and processing them through deconvolution algorithms, the method extracts chemical composition information from the temporal evolution of the signal, achieving both high measurement precision and improved acquisition rate compared to single-point sampling.

The patent applies feedback through iterative deconvolution algorithms that process the time-resolved signal to extract the impulse response function. The algorithm uses the measured thermal response at multiple time points and iteratively refines the estimate of the chemical composition and thermal parameters. This computational feedback mechanism allows the system to achieve high spatial resolution and sensitivity by extracting maximum information from the limited temporal sampling, while maintaining reliable signal-to-noise ratios through mathematical reconstruction rather than simple temporal averaging.