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Use of near infrared spectroscopy for the clinical monitoring of adult brain

1996; SPIE; Volume: 1; Issue: 4 Linguagem: Inglês

10.1117/12.252413

1560-2281

Peter J. Kirkpatrick,

Non-Invasive Vital Sign Monitoring

Adult near infrared spectroscopy (NIRS) is a potential method for noninvasively assessing changes in cerebral oxygenation. Unlike neonatal NIRS, access of light to the adult brain requires penetration through thick extracranial tissues, and hence detection of changes in cerebral chromophore concentration can only be achieved by using NIRS in the reflectance mode. This adds variables that are difficult to control. They include the effects of a different intraoptode distance, intersubject anatomical variation, and the influence of a pathological extra- to intracranial collateral blood supply. Although studies showing movements of oxyhemoglobin concentration following specific cerebral stimuli have been published, the separation of changes occurring in the extracranial and intracranial compartments remains a challenge. Experience with NIRS in the three adult clinical scenarios of carotid endarterectomy, head injury, and carbon dioxide stress testing is presented. The influence of extracranial contamination is demonstrated, as are the methods adopted to help control for extracranial blood flow changes. Provisional experience with spatially resolved spectroscopy (SRS) technology is also discussed.