Abstract: A method of characterizing the respiratory properties of a conscious living organism from a single respiratory waveform containing thoracic and nasal flow signal components is described that includes acquiring a single box flow waveform containing thoracic and nasal flow signal components, measuring the areas of peaks of the waveform, and characterizing respiratory properties from the peak areas. A method is also described for characterizing the respiratory function of a conscious living subject by acquiring separate thoracic and nasal respiratory waveforms, determining the phase shifts between the waveforms at first and second time spaced points, determining the net inspired volume between the points, and characterizing respiratory function using the phase shift and net inspired volume.

Abstract: A whole body plethysmograph for pulmonary measurements of unrestrained small animals includes a cylindrical animal chamber and an integral reference chamber. The animal chamber and the reference chamber each include ports for receiving transducer nipples. The animal chamber and the reference chambers also include ports for selectively venting each of the chambers. A port is mounted in a bulkhead which separates the animal chamber and the reference chamber, and a length of tubing extends from the valve into the reference chamber for providing a high resistance bleed path between the animal chamber and the reference chamber. The plethysmograph further includes an aerosol manifold in the top of the animal chamber. The aerosol manifold includes a plurality of radially extending apertures for uniformly distributing the aerosol in the animal chamber. The plethysmograph still further includes two pneumotachographs in the top of the animal chamber.