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15 July 1999 Feasibility of frequency domain NIR spectrometer to measure fetal cerebral blood oxygenation in utero
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Proceedings Volume 3597, Optical Tomography and Spectroscopy of Tissue III; (1999)
Event: BiOS '99 International Biomedical Optics Symposium, 1999, San Jose, CA, United States
We present a preliminary assessment of the feasibility of using a frequency domain spectrometer for measuring fetal cerebral blood oxygenation in-utero at 750 and 780 nm of modulation at 70 MHz. The amplitude and phase of the diffuse photon density wave which propagates through the tissue is detected by a photomultiplier tube. The absorption coefficient ?a and the reduced scattering coefficient ?'s are calculated based on the analytic solution of the photon diffusion equation for a semi-infinite geometry. The accuracy of the instrument and the algorithm in measuring ?a is tested by an experiment performed on a homogeneous ink/intralipid tissue phantom. Also the sensitivity of the system to the change of blood volume and oxgenation is evaluated through a homogeneous blood/intralipid tissue phantom experiment. Clinical data was recorded during the elective Cesarean section of human subjects. The measurements were made on maternal abdomen in the post-epidural stage and on the fontanel region of neonate before (pre-cord) and after (post-cord) the umbilical cord was detached. The source detector separation used were 7 and 3(or 4) cm respectively. The deoxygenated and oxygenated hemoglobin concentration, blood volume and saturation were calculated based on ?a of 2 wavelength. The averaged optical properties and blood parameters for each stage are presented. The post-epidural blood saturation value correlates well with the pre-cord saturation value. A larger number of human subjects are being evaluated to provide statistically significant results.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Re-Gine Choe, Gargi Vishnoi, Nirmala Ramanujam, Vasilis Ntziachristos, Shoko Nioka, Britton Chance, Arjun G. Yodh, Martha E. Rode, Iraj Forouzan, and Mark Morgan "Feasibility of frequency domain NIR spectrometer to measure fetal cerebral blood oxygenation in utero", Proc. SPIE 3597, Optical Tomography and Spectroscopy of Tissue III, (15 July 1999);

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