TWO MORE RESPIRATORS

Assisted ventilation using cuirass respirators.

The effects of cuirass-assisted ventilation have been studied in 25 subjects with chest wall disease. Cuirass respirators increase ventilation in proportion to the peak negative pressure within the cuirass shell and the respiratory rate. Positive pressure applied during expiration produces little additional ventilation. During cuirass-assisted ventilation end-expiratory volume increases, arteri...

Drinker's "Iron Lung" and Other Artificial Respirators

Motion by releasing the oxygen from the cylinder. There was also a bag (as in Haldane's oxygen apparatus) Which served to keep the oxygen pressure from rising too high in the delivery tube. Thus the oxygen on its Way to the face kept the pump working, and this produced alternately a negative and positive pressure in the delivery tube provided the face-piece was closely applied to the face. This...

Two patients with occupational asthma who returned to work with dust respirators.

OBJECTIVES To assess the efficacy of dust respirators in preventing asthma attacks in patients with occupational asthma (asthma induced by buckwheat flour or wheat flour). METHODS The effect of the work environment was examined in two patients with occupational asthma with and without the use of a commercially available mask or a dust respirator. Pulmonary function tests were performed immedi...

Comparing More Than Two Groups

More planar two-center algorithms

This paper considers the planar Euclidean two-center problem: given a planar n-point set S, nd two congruent circular disks of the smallest radius covering S. The main result is a deter-ministic algorithm with running time O(n log 2 n log 2 log n), improving the previous O(n log 9 n) bound of Sharir and almost matching the randomized O(n log 2 n) bound of Eppstein. If a point in the intersectio...