A novel hyperspectral lifetime probe for autofluorescence

The application of autofluorescence in non-invasive medical diagnostics could have great potential. Two major drawbacks inherent to this approach are low signal levels compared to those from exogenous fluorescent probes and complexity caused by the multiplicity of fluorescent biomolecules in tissue. Here we present a new optical system that is based on single channel detection via an optical fiber and can measure the fluorescence emission spectrum and fluorescence lifetime simultaneously for excitation wavelengths of 355 and 435nm. Single channel measurements integrate the signal normally available in an imaging setup and therefore have a better signal-tonoise ratio. Resolving both the fluorescence emission spectrum and fluorescence lifetime provides the opportunity to discriminate multiple fluorophores. This instrument is intended for NAD(P)H and flavin measurements for the dynamic monitoring of cellular metabolism and optical measurements of cancerous tissue. Initial results from a study of live cells and a clinical study of human skin lesions are presented.