pulse oximetry measures the relative concentration of arterial oxygenated hemoglobin and reduced hemoglobin. this paper presents the design of a pulse oximeter, which measures the presence of a third substance, carboxyhemoglobin (hbco), by unfiltered leds at 660 nm, 810 nm, and 940 nm. background information is given on the theory of pulse oximetry. theoretical approximations and calculations w...

BOLD Effect (Blood Oxygen Level Dependent Effect) The change in T ∗ 2 that is caused by changes in the amount of oxygenated hemoglobin in the venous circulation of the brain. Because oxygenated hemoglobin has a much smaller magnetic susceptibility than deoxygenated hemoglobin, and because neural activity causes a change in the amount of oxygenated hemoglobin in the venous blood, the magnetic su...

OBJECTIVE We hypothesize that there is a difference in the cerebral-oxygenation status between cyanotic and non-cyanotic congenital heart disease when commencing a crystalloid-primed cardiopulmonary bypass (CPB). We tested this hypothesis by using near-infrared spectroscopy (NIRS). METHODS Group 1 consisted of ten patients with non-cyanotic congenital heart diseases, including atrial septal (...

OBJECTIVE To describe a toolkit of components for mathematical models of the relationship between cortical neural activity and space-resolved and time-resolved flows and volumes of oxygenated and deoxygenated hemoglobin motivated by optical intrinsic signal imaging (OISI). APPROACH Both blood flow and blood volume and both oxygenated and deoxygenated hemoglobin and their interconversion are a...

OBJECTIVE The objective of this study was to quantify shoulder muscle fatigue during repetitive exertions similar to motions found in automobile assembly tasks. BACKGROUND Shoulder musculoskeletal disorders (MSDs) are a common and costly problem in automotive manufacturing. METHOD Ten subjects participated in the study. There were three independent variables: shoulder angle, frequency, and ...

Micropipette aspiration tests on single erythrocytes have previously shown that the static rigidity (membrane shear modulus) of oxygenated sickle cells increased with increasing hemoglobin concentration, whereas the rigidity of normal cells was independent of hemoglobin concentration. Moreover, it was observed that after mechanical extension, sickle cells exhibited persistent deformation more f...

Thermodynamic properties of sickled and normal hemoglobin protein are considered within the framework classical molecular dynamics. Here we have studied specific heat capacity RMSD (Root Mean Square Deviation) both types protein. Our investigation reveals that for oxygenated is higher than those de-oxygenated sickle It also observed values decrease with a rise in temperature.
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As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenate...

fMRI does not measure neural activity directly. Instead, it measures small and variable changes in the ratio of oxygenated to deoxygenated blood in the brain when a particular task is performed or stimulus presented—the so-called BOLD, or blood oxygen level-dependent, response. Firing neurons, like working muscles, require oxygen; follow the trail of oxygenated hemoglobin, and you find neural a...