Region Ostergotland 1 article published in JoVE Neuroscience Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb Joakim Henricson1,2, Rani Toll John1,3, Chris D. Anderson4,5, Daniel Björk Wilhelms1,2 1Department of Emergency Medicine, Local Health Care Services in Central Östergötland, Region Östergötland, 2Division of Drug Research, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, 3Division of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University, 4Division of Cell Biology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, 5Department of Dermatology and Venerology, Heart and Medicine Center, Region Östergötland This protocol describes how the use of diffuse polarization spectroscopy can improve the clinical usefulness of the capillary refill test. We suggest a more detailed analysis of the course of the capillary refill in healthy volunteers using diffuse reflectance spectroscopy videos and new informatic endpoints.