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Biomedical subjects

B Jonson

Publications and source records attributed to B Jonson.

At least 145 records · Page 8Linked to original sources

Noise reduction of ECG by averaging. An experimental study of the procedure and a validated method.

Electrical noise often hampers the interpretation of ECG and other heart-synchronous signals. Time-coherent averaging is a commonly used method to reduce the noise. This method has been implemented on a computer with 12,000 12-bit words of core memory, suitable for on-line use in any clinical laboratory. An analysis was made of which demands apply to the exactness of synchronization of added heart cycles. The method was tested with respect to these demands and also, on a limited scale, for its efficiency in eliminating ectopic beats from the average.

Computers↗

Bronchodilatory and circulatory effects of inhaling increasing doses of an anti-cholinergic drug, ipratropium bromide (SCH 1000).

Dynamic spirometry with flow-volume curves and measurement of static lung volumes in a body plethysmograph were done in 11 patients with reversible airways obstruction before and up to 240 min after inhalation of 20 mug SCH 1000 and of another 40 mug 60 min later. Forced expiratory volume in 1 s (FEV1), vital capacity (VC) and maximal expiratory flow at 50% VC (V 50% VC) increased successively, reaching maximum after 120 min. In a second part of the study 13 patients inhaled 2+4+8 puffs of SCH 1000 (280 mug in all) at 30-min intervals. PEFR increased significantly up to 224 l/min (44% of predicted normal), with increasing number of SCH 1000 inhalations; no further general effect occurred after additional 3 puffs of terbutaline. Heart rate and blood pressure showed no clinically significant changes. No subjective or objective side-effects were noted.

Adult↗