 1. Prior authors have demonstrated that tissue spectroscopy can be used in both animal human experiments to detect and differentiate between tissue transfer flaps with adequate vascular supply vs. flaps with either artery andor vein occlusions prior to the detection of such complications using standard clinical observation during the post-operative period. These authors demonstrated that detection of the changes from baseline values in the post-operative period of the total hemoglobin Hb-total, deoxygenated hemoglobin Hb-deoxy, and oxygenated hemoglobin Hb-O2 concentrations using tissue spectroscopy correlated with the clinical development of arterial or venous occlusion. 1,2 As the MI device developed at the Beckman Laser Institute has been demonstrated to be able to detect the Hb-total, Hb-deoxy and Hb-O2 as well as the concentration of water,H2O in a non-contact manner; we believe the MI device will also be able to detect development of arterial and or venous occlusion in tissue transfer flaps without requiring direct tissue contact with a tissue spectroscopy device, as was the case with the instruments used by other authors.3, 4 