Figure 1

Clinical prototype. (a) 3D model of the custom-made portable prototype employed to record microscopy videos of the microcirculation in nailfold capillaries of patients, with its different components. (b) Patients place their ring finger in a 3D-printed holder, which plays a dual role: achieving stability throughout the one-minute recording duration and holding the oil employed for optical coupling. (c) The finger is placed so that illumination and imaging is directed at the nailfold area (dashed purple line).