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Proceedings Paper

A fiber optic probe for measurement of an autonomic dysreflexia event on SCI patients
Author(s): J. C. Ramella-Roman; J. M. Hidler
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Paper Abstract

Autonomic Dysreflexia (AD) is an inappropriate response of the sympathetic nervous system that often occurs in individuals with spinal cord injury (SCI ) at or above the sixth thoracic vertebrae (T6) level when a noxius stimulus is applied below the level of injury. An AD event can be put into motion by something as simple as an ingrown toenail or a full bladder, with symptoms such as headache, elevated blood pressure, reduced heart rate, decreases in blood flow below the level of injury, and in extreme cases, stroke. We have developed a quantitative method of measuring skin oxygen levels during AD using a fiber optics based probe. Two such probes were located above and below the injury level (on the patient forearm and thigh respectively) and were connected to a dual channel spectrophotometer. Oxygen saturation was calculated using the reflectance spectra and an algorithm based on melanin and hemoglobin absorption. We found that during an AD event, the amount of oxygen in the skin below the injury level drops by as much as 40%, while above the injury level skin oxygenation remains constant. Additionally, we observed elevated persperation levels below the injury level. We hypothesize that the combination of AD-related ischemia with pressure related ischemia and increased perspiration places individuals with injury level at T6 or above at significant risk for developing a pressure sore below the injury site.

Paper Details

Date Published: 5 February 2008
PDF: 5 pages
Proc. SPIE 6852, Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications VIII, 685202 (5 February 2008); doi: 10.1117/12.768714
Show Author Affiliations
J. C. Ramella-Roman, The Catholic Univ. of America (United States)
J. M. Hidler, The Catholic Univ. of America (United States)

Published in SPIE Proceedings Vol. 6852:
Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications VIII
Israel Gannot, Editor(s)

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