@inproceedings{prahl92c,
  author = {S. A. Prahl and U. Bruggemann and R. R. Anderson},
  title = {Pulsed Photothermal Radiometry of Human Skin Following Exposure to Mid-ultraviolet Light},
  booktitle = {SPIE Proceedings of Lasers in Dermatology and Plastic Surgery},
  year = {1992 abstract only},
  abstract = {Pulsed Photothermal Radiometry (PPTR) measures blackbody radiation emitted by a sample after absorption of an optical pulse. A method for analyzing PPTR signals has been developed which extracts the internal heat source distribution from measurements of the surface temperature. This method is applicable to materials with uniform thermal properties, but having optical properties which vary as a function of depth. A robust algorithm has been obtained using singular value decomposition. This algorithm has been validated using agar-gelled phantoms containing various mixtures of dye and scatterers. PPTR measurements using 630\,nm light were made on ten subjects whose skin was exposed to twice their minimum erythma dose of mid-ultraviolet light. Measurements were made on both exposed and unexposed skin sites on days 2, 5, 10, 15 and 20 following exposure. Since the dominant absorber in skin at 630\,nm is melanin, the internal heat source distribution should be directly related to the melanin profile. These profiles are compared with diffuse reflection measurements and with each subject's minimal erythema dose.},
}