Paper
7 December 2004 Development of a portable multiphoton photo-acoustic spectroscopy system for tumor diagnostics
Author Affiliations +
Proceedings Volume 5588, Smart Medical and Biomedical Sensor Technology II; (2004) https://doi.org/10.1117/12.568107
Event: Optics East, 2004, Philadelphia, Pennsylvania, United States
Abstract
In this paper we describe the development of a novel fiber optic probe for subsurface tumor diagnostics, based on non-resonant multiphoton photoacoustic spectroscopy (NMPPAS). In this technique, endogenous biomarkers present in tissues are irradiated in the near infrared, using a tunable high-power laser. The resulting multiphoton excitation events are detected as an acoustic (i.e. ultrasonic) signal, using an ultrasonic piezoelectric transducer. The signal from the piezoelectric transducer is then corrected for laser power fluctuations by normalizing the NMPPAS signal at each wavelength with the laser intensity recorded, from an optical diode. By scanning the laser excitation over the appropriate wavelength range for the tissue of interest, absorption differences between normal and tumor tissues can be measured and analyzed. The fiber optic probe was characterized and optimized for transmission efficiency as well as its time dependent response to high power laser pulses. The focusing optics were optimized and a piezoelectric transducer film detector chosen based on its sensitivity in the ultrasonic frequency range of interest. Using this probe system NMPPAS measurements were performed on several common fluorescent dyes including rhodamine 6G as well as well-characterized biomarkers like tryptophan. Furthermore, the technique was further successfully applied to the differentiation of tumorous and healthy human brain tissues.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Nirmala Chandrasekharan, John B. Kiser, and Brian M. Cullum "Development of a portable multiphoton photo-acoustic spectroscopy system for tumor diagnostics", Proc. SPIE 5588, Smart Medical and Biomedical Sensor Technology II, (7 December 2004); https://doi.org/10.1117/12.568107
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KEYWORDS
Tissues

Tumors

Fiber optics

Transducers

Brain

Diagnostics

Photoacoustic spectroscopy

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