For the purpose of retinal oximetry, this requires the measurement of light absorption at a minimum of two wavelengths to determine the relative concentrations of oxyhaemoglobin
and deoxyhaemoglobin, and, therefore, enabling the oxygen saturation of a blood vessel to be determined.
Gastric mucosal NOS activity was measured spectrophotometrically using the oxidation of oxyhaemoglobin
to methaemoglobin by NO as described previously (Knowles et al.
The absorption of oxyhaemoglobin
and deoxyhaemoglobin at these two wavelengths is very different.
Three-dimensional fourier synthesis of horse oxyhaemoglobin
The level of oxygen in the blood is calculated from the ratio of absorbed red to infrared light using the ratio of oxyhaemoglobin
to the sum of all the functional haemoglobin.
In severely anaemic patients, CT may miss a haemorrhagic lesion due to low oxyhaemoglobin
Maximal or minimum values during the exercise period were used to determine absolute concentration changes for deoxyhaemoglobin ([DELTA]HHb), oxyhaemoglobin
(DELTA]O2Hb), total haemoglobin (DELTA]cHb), and tissue oxygenation index (TOI, the ratio of oxygenated to total tissue haemoglobin) and normalised tissue haemoglobin index (nTHI, the relative concentration of total haemoglobin).
reaches the body's oxygen-hungry tissues, it then releases its oxygen.
1) Since then, near-infrared spectroscopy (NIRS) has been used to monitor oxyhaemoglobin
, deoxyhaemoglobin, blood volume and cytochrome oxidase for a variety of clinical and research applications.
Hypopnoea was defined as a discernible reduction in respiratory airflow during a preceding period of normal breathing for [greater than or equal to] 10 sec accompanied by a decrease of 4 per cent or more in oxyhaemoglobin
saturation during sleep.
Sleep Disordered Breathing (SDB) is characterized by repetitive upper airway obstruction and consequent oxyhaemoglobin
desaturation during deep stages of sleep.
Blood pressure was monitored non-invasively every five minutes throughout surgery and heart rate via electrocardiogram and oxyhaemoglobin
saturation (pulse oximetry) monitored continuously.