Portable spatial frequency domain imaging using open-source tools.
SAMPAIO, Murilo Sanches; CRUZ JUNIOR, Luismar Barbosa da; BARROS, Kaio Bernardo de; OLIVEIRA, Julia Cristina da Silva; MONTE, Adamo Ferreira Gomes do; CUNHA, Diego Merigue da; BACHMANN, Luciano.
SAMPAIO, Murilo Sanches; CRUZ JUNIOR, Luismar Barbosa da; BARROS, Kaio Bernardo de; OLIVEIRA, Julia Cristina da Silva; MONTE, Adamo Ferreira Gomes do; CUNHA, Diego Merigue da; BACHMANN, Luciano.
Abstract: Non-invasive mapping of light-tissue properties is essential in biomedical optical diagnostics and therapy. Spatial Frequency Domain Imaging (SFDI) enables wide-field assessment of the optical coefficients through structured-light projection; however, conventional systems depend on bulky projectors and external computers. In this study a portable and open-source SFDI system were developed by combining LED projector, Raspberry Pi 4B, and Pi Camera OV5647 to map tissue absorption (????) and reduced scattering (????') coefficients in real time without external computing. Five onboard models were benchmarked using Monte Carlo references and validated on calibrated phantoms at 640 nm. The exponential fit was fastest (0.0016 s) but least accurate (15% ????, 45% ????' error). Rational fit improved accuracy (12% ????, 14% ????' error), with runtime of 0.0019 s. Neural networks achieved best accuracy (3% ????, 12% ????' error), while maintaining acceptable runtime of 0.040 s. KNN matched accuracy (6% ????, 14% ????' error) but was slowest (0.070 s). These findings indicate good precision on the optical properties measuring using a portable system, and opening possibilities for real-time monitoring in future clinical applications.
@article={003290809,author = {SAMPAIO, Murilo Sanches; CRUZ JUNIOR, Luismar Barbosa da; BARROS, Kaio Bernardo de; OLIVEIRA, Julia Cristina da Silva; MONTE, Adamo Ferreira Gomes do; CUNHA, Diego Merigue da; BACHMANN, Luciano.},title={Portable spatial frequency domain imaging using open-source tools},journal={Instrumentation Science and Technology},note={v. 54, n. 2, p. 172-191},year={2026}}