A combined Raman-fluorescence spectroscopic probe for tissue diagnostics applications

We designed and developed two different optical fibre probes for combined Raman and fluorescence spectroscopic measurements on human tissues. The experimental setup combines fluorescence spectroscopy and Raman spectroscopy in a multimodal approach. Two laser diodes, respectively emitting in the UV (378 nm) and in the visible (445 nm), were used for fluorescence spectroscopy. An additional laser diode emitting in the NIR (785 nm) was used for Raman spectroscopy. Laser light was delivered to the tissue under examination through a multimode optical fibre located in the centre of the fibre bundle probe. The surrounding 24 optical fibres were used for collection of the signal of interest and for delivering light to a common detection unit. Both fluorescence and Raman spectra were acquired on a cooled CCD camera, connected to a spectrograph. The device was successfully used for diagnosing melanocytic lesions in a good agreement with common routine histology. Additional measurements were performed on other human tissue samples, such as colon tissue and brain tissue in order to test the capability of the device for diagnosing a broader range of tissue lesions and malignancies. The system has the potential to improve diagnostic capabilities on a broad range of tissues and to be used for endoscopic inspections in the near future. © 2013 OSA-SPIE.