Yasuaki HORI, Takeshi YASUI and Tsutomu ARAKI

Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan

(Received September 30, 2004; Accepted February 15, 2005)

We have designed a novel multiple-scattering-free optical glucose monitoring system based on femtosecond pulse interferometry. The glucose concentration is determined by a time-of-flight method, while multiple-scattering light is rejected by a coherence gate. The resultant accuracy and precision were 94.7 and 24.5 mg/dl, respectively, for physiological-equivalent glucose concentrations in a scattering medium of 1.0% intralipid solution, while the accuracy and precision for a reference sample containing no scattering medium were 65.3 and 23.8 mg/dl, respectively. Comparing these results, we conclude that the proposed method is effective for glucose measurement in a scattering medium.

Key words: glucose, femtosecond pulse light, multiple scattering, coherence gate, interferometry, time-of-flight, group refractive index