We combine two near-infrared diffuse optical techniques to study variations of blood flow, haemoglobin concentration, and blood oxygen saturation in the functioning rat brain. Diffuse correlation spectroscopy (or flowmetry) monitors changes in the cerebral blood flow, without the use of the principles of tracer clearance, by measuring the optical phase-shifts caused by moving blood cells. Near-...

A combined stopped flow-laser photolysis apparatus was used to measure the quantum efficiency for removal of carbon monoxide bound to human hemoglobin as a function of fractional CO saturation. This flow-flash technique allows the properties of partially liganded hemoglobin molecules, which are sparsely populated under equilibrium conditions, to be conveniently studied. Experiments performed at...

Accurate integration of flow simulation and seismic modeling is one of the cornerstones of reliable time-lapse (4D) seismic monitoring. However, the question which scales flow simulations need to resolve to accurately capture reservoir changes during production and whether these scales are resolvable in seismic data is an open one. The answer impacts computational costs and our ability to predi...

We observed the response of vascular resistance and venous oxygen (O2) saturation to sinusoidally modulated continuous exercise of the isolated dog calf. Stimulus frequency was varied sinusoidally between 0.5 Hz and 1 Hz with modulation frequencies ranging from 0.005 Hz to 0.05 Hz. Venous O2 responses were corrected for dispersion due to vascular and catheter transit. As modulation frequency wa...

Adequacy of perfusion during cardiopulmonary bypass (CPB) is dependent on nutrient delivery and waste removal from the tissue. A recent study showed that over 75% of cardiopulmonary bypass procedures are completed using continuous venous saturation (SvO2) monitoring. The purpose of this study was to determine the effect of changing FiO2concentration on SvO2. A total of eight mixed gender 45-kg ...

AN69 membrane is not suited for diffusion, with an suggested limit at 25 mL/min dialysate flow rate. When prescribing continuous hemodialysis this threshold must be surpassed to achieve. We designed a study aimed to check if a higher dose of dialysis could be delivered efficiently with this membrane. Ten ICU patients under continuous hemodiafiltration with 1.4 m(2) AN69 membrane were included a...

Background. Given the influence of systemic blood pressure on pulpal blood flow, anxiolytics prescribed may alter the pulpal blood flow along with the local anesthetic solution containing a vasoconstrictor. This study evaluated the impact of preoperative anxiolytics and vasoconstrictors in local anesthetic agents on pulpal oxygen saturation. Methods. Thirty anxious young healthy individuals wit...

BACKGROUND Mathematical modeling of cardiovascular magnetic resonance perfusion data allows absolute quantification of myocardial blood flow. Saturation of left ventricle signal during standard contrast administration can compromise the input function used when applying these models. This saturation effect is evident during application of standard Fermi models in single bolus perfusion data. Du...