Fig. 4: Hypoxia and intravascular exogenous agent concentration decay tests on mice.

a The hypoxia experiment setup for in vivo animal tests. b The linear correlation between sO2 and OA amplitudes. c The trend lines of peak-to-peak values of the OA signals measured by OBS in the hypoxia test. The orange regions represent periods with nitrogen supply (low oxygen status). Blue and red lines are OA amplitudes of veins and arteries, respectively. The gray region represents the oxygen saturation measured by an oximeter. d Snapshot images of the reconstructed 3D mice blood oxygen mapping at 30 s, 320 s, 520 s, 710 s, and 760 s. e The trend lines of peak-to-peak values of OA signals measured by OBS for intravascular exogenous agent concentration monitoring. Rhodamine B metabolism in blood vessels (red line) and the tissues (blue line) show the trend of decay over time. f The decay trend of Rhodamine B in blood (red line) measured from the OBS. The decay coefficient from the solid blue fitted curve is 3.6 × 10⁻⁴ s⁻¹, R² = 94.3%, and RMS = 91.8%. g The decay trend of Rhodamine B in blood (red points) measured from the in vitro fluorescence method. The decay coefficient from the solid blue fitted curve is 3.22 × 10⁻⁴ s⁻¹, R² = 88.4%, and RMS = 86.4%. h Snapshot images of 3D mice Rhodamine B concentration mapping at 200 s, 700 s, 1200 s, and 1900 s in concentration decay test. Rhodamine B in the blood is rendered orange, whilst Rhodamine B in tissues is rendered purple. Source data are provided as a Source Data file.