25 September 2013 Thin photothermal endoscope for biomedical applications
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Abstract
A thin photothermal (PT) endoscope (∼80  μm ) for the noninvasive/minimally invasive hybrid-optical diagnosis of biological specimens is demonstrated. The technique has the unique advantage that the pump laser delivery fiber itself acts as the thermal wave sensor, which is a Bragg grating. It detects only the conductive component of the PT signal, thus enabling an emissivity independent measurement. The device is slidable through a syringe needle and PT analysis of exposed organs with limited accessibility for conventional PT techniques, and constricted regions can be examined noninvasively. For regions buried in thick tissues, a minimally invasive injection mode may be considered. Temperature measurement sensitivity is about 0.03°C. The amplitude and phase channels are sensitive up to about 3 and 10 kHz, respectively. The endoscope has been used for the simultaneous estimation of flow velocity, absorption coefficient, and diffusivity for a phantom-blood flow. The endoscopically estimated values are in agreement with true flow velocities over a range of 1 to 1000  cm −1 . The endoscope has been used for the optical biopsy of goat bone marrow.
© 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)
Sreekumar Kaiplavil, Sreekumar Kaiplavil, } "Thin photothermal endoscope for biomedical applications," Journal of Biomedical Optics 18(9), 097008 (25 September 2013). https://doi.org/10.1117/1.JBO.18.9.097008 . Submission:
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