Thermal Imaging of the Superficial Temporal Artery: An Arterial Pulse Recovery Model
We present a novel model for measurement of the arterial pulse from the superficial temporal artery (STA) using passive thermal infrared (IR) sensors. The proposed approach has a physical and physiological basis and as such is of fundamental nature. Thermal IR camera is used to capture the heat pattern from superficial arteries, and a blood vessel model is used to describe the pulsatile nature of the blood flow. A multiresolution wavelet-based signal analysis approach is used to extract the arterial pulse waveform, which lends itself to various physiological measurements. We validate the results using a traditional contact vital-sign monitor as a ground truth. Eight people of different age, race and gender have been tested in our study consistent with IRB approval. The resultant arterial pulse waveforms exactly matched the ground-truth readings. The essence of our approach is the automatic detection of region of arterial pulse measurement (ROM), from which the arterial pulse waveform is extracted. To the best of our knowledge, the correspondence between non-contact thermal IR imaging based measurements of the arterial pulse in the time domain and traditional contact approaches has never been reported in the literature.