In this master’s thesis, we investigated the effect of blue laser light with a wavelength of 445 nm on blood coagulation. Due to its higher absorption in hemoglobin compared to green laser light (532 nm), blue light proves more effective in stopping bleeding. The aim of the study was to experimentally determine key interaction parameters for reliable and non-ablative blood coagulation. We developed an experimental system featuring synchronized operation of a high-speed thermal camera and an ultra-fast visible-spectrum camera, enabling precise monitoring of temperature and optical changes during the process. Based on the analysis of the recordings, we determined the temperature thresholds for the onset of coagulation and ablation and tracked optical changes in the blood. We identified a safe coagulation temperature window (85–145 $^°$C) and established fluence thresholds for its onset at different laser powers (3.1–4.5 J/$cm^2$). Additionally, we defined the fluence thresholds for the transition to ablation, which ranged from 13.6 to 23.9 J/$cm^2$. The developed methodology enables detailed analysis of the coagulation process and provides a solid foundation for further development of clinical applications of blue laser light in bleeding control.
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