EOX for Noninvasive Physiologic Monitoring

Abstract

An EOX is an instrument that scans low-powered lasers into a subject's eye and spectroscopically determines oxygen saturation of blood within the retinal veins and arteries. Pilot animal studies performed by our group with an EOX indicate that retinal venous oxygen saturation is a sensitive indicator of blood loss. We have developed a 2-D scanning EOX which is readily reconfigured to operate at various wavelengths, and to use confocal techniques and polarization to constrain the potential sources of collected light. Thus, the instrument is being used to fully explore the physics of retinal oximetry, with the goal of a calibrated instrument. The parallel development of a model eye allows for rapid verification of EOX modifications on a test object with far fewer unknowns. Data collection across varying oxygen saturation, hemoglobin concentration, vessel diameter, fund us reflectivity, and filtering configurations permits analysis of the contributions of each of these components to the actual complex measurement. This data has been critical to improving our understanding of the algorithms necessary for calibrating the EOX. Finally, a human pilot study performed on subjects in a Lower Body Negative Pressure experiment was also accomplished, successfully acquiring data on 15/15 subjects.

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Document Details

Document Type
Technical Report
Publication Date
Jun 28, 2002
Accession Number
ADA403422

Entities

People

  • Art Lompado
  • Lloyd W. Hillman
  • Patrick J. Reardon

Organizations

  • University of Alabama in Huntsville

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Arteries
  • Blood
  • Cardiovascular Physiological Phenomena
  • Diameters
  • Hemoglobin
  • Lasers
  • Measurement
  • Medical Personnel
  • Monitoring
  • Optical Properties
  • Oxygenation
  • Physiological Monitoring
  • Reflectivity
  • Retinal Vessels
  • Saturation
  • Scanning
  • Vital Signs

Fields of Study

  • Physics

Readers

  • Oncology and Biomarker-Based Cancer Detection.
  • Optical Physics and Photonics.
  • Trauma Surgery or Emergency Medicine.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers