RiverD International has completed the development of a fiber-optic Raman-module for use with single fiber optical probes. Laser, beam shaping optics, highly reproducible fiber optic coupling, laser suppression filtering in the signal collection path, spectrometer and CCD-detector are all integrated in the Raman module. It is controlled by custom-made software, which also performs system calibration and real-time data pre-processing. The Raman module exploits the fact that in the high-wavenumber region (2500-4000 cm-1) of the Raman spectrum signal background of the fiber optic probe itself can be avoided. This huge benefit enables the use of a single fiber to guide laser light to the tissue and to collect Raman scattered light from the tissue. This avoids the necessity/complexity of integrating optical filters at or near the probe tip and provides maximal freedom in defining the size and location of the measurement volume from which tissue Raman signal is obtained. The Raman module and fiber optic probes are currently used in an in vivo study of the oesophagus and colon at the University Medical Center Groningen (NL). The single fiber probes used in this study collect Raman signal from the tissue surface down to a depth of about 200 microns, which believed to be optimal for detection of dysplasia and field cancerisation.
RiverD International has also completed a prototype module for use with multifiber probes, suitable for Raman measurements in both high-wavenumber and fingerprint spectral regions (400-2500 cm-1). In a close collaboration with art photonics GmbH (Berlin (Germany); a company with much expertise in spectroscopic fiber optic probe design and manufacturing), not part of the Sensitive project) fiber optic probes are being developed with optical filtering near the probe tip to suppress the strong interfering background signal of the fiber optic probe material in the fingerprint region.
The development of these high quality Raman modules, software and compatible (application specific) fiber-optic probes, are opening the door to more widespread (investigation of) diagnostic use of fiber-optic Raman spectroscopy.
RiverD plans to drive these developments further towards commercialisation in collaboration with art photonics (https://www.riverd.com/research-applications/fiber-optic-raman-technology-platform/).