Carboxyhaemoglobin and plasma thiocyanate concentrations were measured in 79 non-smokers and 360 cigarette smokers. The mean levels were 0.73% and 7.09% carboxyhaemoglobin and 40 . 2 and 133 . 8 mumol thiocyanate/1 plasma respectively. With 1 . 6% carboxyhaemoglobin and 73 . 0 mumol thiocyanate/1 plasma as critical values the concentrations of carboxyhaemoglobin in 96.6% of subjects and of thio...

Blood carboxyhaemoglobin (HbCO%) levels were measured in 61 workers in 35 garages in Leicester and Leicestershire. Of 26 workers in large garages in winter, 44% of the non-smokers and 20% of the smokers had increased CO absorption, the highest HbCO% being 26.0 in a non-smoker. Of 35 workers in 24 smaller, randomly chosen garages visited throughout the year (two per month) the corresponding figu...

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...

Camera-based pulse-oximetry has recently shown to be feasible, even when the signal is corrupted by noise and motion artifacts. Earlier work showed that using three instead of the common two wavelengths improves robustness of the measurement, however without a thorough investigation on the optimal wavelength selection. We therefore performed a search to identify these wavelengths to further imp...

The principal function of the protein hemoglobin contained in red blood cells is transport of oxygen in inspired air from lungs to tissue cells. Although normally present in only trace amounts, there are three species of hemoglobin that cannot transport oxygen. The three species, collectively called the dyshemoglobins because of their functional redundancy, are: carboxyhemoglobin, sulfhemoglobi...

The substances inhaled from tobacco smoke not only act on the vessel wall but also influence eryth rocyte behaviour. The effect of chronic tobacco con sumption on red cell filtration, leading to a rise of the filtration time, is widely known.1-3 This work was meant to study the influence of acute tobacco intoxication on blood filtration and on oxygen transport by hemoglobin as assessed by the p...