Infrared Microscopy Imaging of Index-Finger Pads

In this paper, we present the mid-wave infrared microscopic view of index finger pads of voluntary subjects, an analysis of their thermoregulation response, and a study of their thermal spatial morphology. This is accomplished by means of a custom-made mid-wave infrared imager fitted with appropriate infrared optics. The microscopic thermal images enable us to capture spatial and temporal thermal information emitted from the microscopic finger pad’s blood vessels and irrigation system, spatially attenuated by the finger pad’s skin morphology. As a consequence, we can acquire and extract features that visual-spectrum microscopes or regular infrared imagers are not able to disclose. The thermoregulation response is acquired by exposing to a thermal stress the finger pads of voluntary subjects, while a microscopic infrared sequence was recorded. We used standard infrared imaging and signal processing techniques to extract the thermoregulation curves of the infrared sequences, and the thermal morphology features were estimated from the same imagery. One of the key findings of this paper is that three distinctive index finger pads infrared morphology patterns were identified, and important insights of the thermal behavior of the micro-spatial finger pad anatomy were observed for the very first time.