Single snapshot spatial frequency domain imaging with real-time 3D profile correction

We have proposed a novel single-snapshot spatial frequency domain imaging method with synchronous three-dimensional (3D) profile correction that addresses the confounding effects of involuntary jitter in tissue under examination and the 3D profile of the tissue on the measurements of optical parameters during in vivo examinations. I. In this scheme, orthogonal composite sinusoidal modulated light is projected onto the tissue to be measured. The single-snapshot multi-frequency demodulation theory, combined with the different sensitivity of different directional fringes to heights, simultaneously recovers the 3D profile and the modulated diffuse reflectance of the tissue to be measured. Finally, the modulated diffuse reflectance is corrected by establishing the correction function of height and angle versus modulated diffuse reflectance, and the optical parameters of the tissue are inverted by the diffusion model. The accuracy of the 3D profile measurement of the scheme was verified using models with different morphologies, and the mean value of the measurement error was found to be lower than 3%. The accuracy of modulation diffuse reflectance measurement was verified using a hemispherical homogeneous phantom made of PTFE. After correction with this method, the standard deviation of the measured diffuse reflectance is reduced by up to 72.2%. Finally, the measurement effect of optical parameters is verified by in vivo experiments and compared with the standard three-phase method. The results demonstrated that the 3D-SSMD method exhibits enhanced stability and efficiency. This introduces an innovative technology for achieving real-time spatial frequency domain imaging, applicable in clinical settings.