Preliminary note on a method of registering pulmonary ventilation

Abstract

A dcscription is given oí an apparatus to register quantitatively pulmonary ventilation. A spirometer bell divided into two parts oí tlie same volume and tabes with rubber valves are arrenged as may be seen in the sketch. The registering as per this system has the advantage of a closed circuit, one half oí the spirometer bell being connected to the lungs and isolatcd from the atmosphere while the other half is disconnected from the lungs and opened to the atmosphere. In this way ventilation is assured at all times. The expansion of the thorax during inspiration closes, by means of the pneumograph, communication of the spirometer with the atmosphere. Air is coming from this right half to the lungs and by the same inspiration force, the valve connecting the lung with the left half of the spirometer is closed, whilst another valve connecting this cavity with the atmosphere is opened. It will be understood that during expiration the valves operate inversely.

The valve situated at the entrance of atmosphere into the right half of the apparatus, is closed by the pressure of the pneumograph. An electric appliance with a contact opening and closing through air pressure on passing through the trachea, may be employed instead of the pneumograph, or operated by the latter. An analogous appliance may also be utilized for the passing of the air from the expiration side to the atmosphere. The same clectromagnet and contact may serve for the two exits of the apparatus secing that when one opens, the other closes. The method permits quantitative registration of the volunte of air expired and that of air inspired.