Parathyroid Imaging Using NIR Autofluorescence and Speckle Perfusion

The patent combines NIRAF imaging with Laser Speckle Imaging (LSI) into a single integrated system. The detector captures both autofluorescence signals and speckle contrast signals simultaneously or sequentially, allowing the surgeon to evaluate both tissue fluorescence characteristics and perfusion status together. This merging of two detection modalities enables differentiation between true parathyroid tissue and false positives like brown fat, which have different perfusion patterns despite similar fluorescence.

The patent introduces perfusion information as an intermediary parameter to resolve the ambiguity in tissue identification. By adding the speckle contrast metric as an additional diagnostic criterion, the system mediates between the fluorescence signal alone (which causes false positives) and accurate tissue identification. The perfusion status acts as a discriminator that validates or refutes the initial NIRAF-based tissue classification.

The patent utilizes near infrared autofluorescence to induce color changes in tissue that are not visible to the human eye. When illuminated with near infrared light, parathyroid tissue exhibits characteristic fluorescence emission, creating optical contrast against surrounding tissues. This fluorescence-based color change enables clear visualization of tissue boundaries and characteristics that would otherwise be indistinguishable under direct visualization.

The patent replaces direct mechanical/visual inspection with optical detection systems. Instead of relying on the surgeon's eye to directly visualize tissue contrast, the system uses near infrared light sources and detectors to capture fluorescence signals. This substitution of mechanical visualization with optical detection overcomes the limitations of human vision in dark, obstructed surgical fields and provides enhanced tissue contrast.