POSITIVE-NEGATIVE-PRESSURE RESPIRATION PUMP FOR LABORATORY ANIMALS

A positive-negative-pressure respiration pump with one piston for inspiration and one for expiration for tracheotomized laboratory animals is described. The tidal volume ranges from 7-45 ml and the frequency from 20-70 cpm. Respiration with expiratory, symmetrical or inspiratory typus is possible. In experiments with intact thorax during long lating artificial respiration the mean tracheal side pressure should remain close to atmospheric pressure in order to secure minimal mechanical effects upon blood circulation (respectively upon the arterial blood pressure). For this purpose the volumes of both pistons are adjustable to each other. The pump is also applicable in experiments with opened thorax. The instrument allows artificial respiration of rodents of medium size, rabbits, cats and small dogs. © 1969 Springer-Verlag.