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One of the urgent tasks of modern medicine is to detect microcirculation disorder during surgery to avoid possible consequences like tissue hypoxia, ischemia, and necrosis. To address this issue, in this article, we propose a compact probe with sapphire tip and optical sensing based on the principle of spatially resolved diffuse reflectance analysis. It allows for intraoperative measurement of tissue effective attenuation coefficient and its alteration during the changes of tissue condition, caused by microcirculation disorder. The results of experimental studies using (1) a tissue‐mimicking phantom based on lipid emulsion and hemoglobin and (2) a model of hindlimb ischemia performed in a rat demonstrated the ability to detect rapid changes of tissue attenuation confirming the feasibility of the probe to sense the stressful exposure. Due to a compact design of the probe, it could be useful for rather wide surgical operations and diagnostic purposes as an auxiliary instrument. [ABSTRACT FROM AUTHOR]

This article describes a sapphire cryoprobe as a promising solution to the significant problem of modern cryosurgery that is the monitoring of tissue freezing. This probe consists of a sapphire rod manufactured by the edge‐defined film‐fed growth technique from Al2O3 melt and optical fibers accommodated inside the rod and connected to the source and the detector. The probe's design enables detection of spatially resolved diffuse reflected intensities of tissue optical response, which are used for the estimation of tissue freezing depth. The current type of the 12.5‐mm diameter sapphire probe cooled down by the liquid nitrogen assumes a superficial cryoablation. The experimental test made by using a gelatin‐intralipid tissue phantom shows the feasibility of such concept, revealing the capabilities of monitoring the freezing depth up to 10 mm by the particular instrumentation realization of the probe. This justifies a potential of sapphire‐based instruments aided by optical diagnosis in modern cryosurgery. [ABSTRACT FROM AUTHOR]