29 June 2001 Tissue spectroscopy with a newly developed phase modulation system based on the microscopic Beer-Lambert law
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Proceedings Volume 4250, Optical Tomography and Spectroscopy of Tissue IV; (2001) https://doi.org/10.1117/12.434508
Event: BiOS 2001 The International Symposium on Biomedical Optics, 2001, San Jose, CA, United States
Abstract
We have developed a phase and intensity-modulated spectroscopy system (PMS) using a newly developed algorithm based on the microscopic Beer-Lambert law. Experiments with phantoms and the human body demonstrate the feasibility and reliability of the system as well as the new algorithm. Our goal is to develop compact, cost-effective, highly reliable, and user-friendly medical equipment for the quantitative monitoring of oxygen metabolism, and so on. The PMS system consists of three time-shared wavelength laser diodes with a 70MHz modulation frequency as sources and a 3mm diameter silicon PIN photodiode as a detector with an in-phase quadrature demodulator (IQD) for AC amplitude and phase detection. The PIN photodiode is operated at a low voltage and is durable against strong extraneous light. In addition, a specially designed low-noise amplifier is achieve a high S/N and reliable measurement. Our algorithm is independent of boundary conditions, exterior shape, scattering properties of the medium, and optode separation for measurement. We can therefore quantify the absolute concentration for oxy- deoxy-hemoglobin and hemoglobin saturation in living tissue of various shapes precisely.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hidenao Iwai, Tsuneyuki Urakami, Mitsuharu Miwa, Mitsunori Nishizawa, Yutaka Tsuchiya, "Tissue spectroscopy with a newly developed phase modulation system based on the microscopic Beer-Lambert law", Proc. SPIE 4250, Optical Tomography and Spectroscopy of Tissue IV, (29 June 2001); doi: 10.1117/12.434508; https://doi.org/10.1117/12.434508
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