title: A digital computer technique for analyzing respiratory muscle EMG's.
abstract: A method is described for extracting from the electromyograms of respiratory muscles a continuous signal which has primarily the periodicity of respiratory pressure and flow wave forms. The EMG is first band-pass-filtered from 50 to 500 Hz, then digitized, full-wave rectified, passed through a nonlinear voltage window to reduce noise (particularly ECG) artifacts, then low-pass filtered with a digital continuous, or moving, averager. An average wave form corresponding to one respiratory cycle is produced by ensemble averaging of the wave forms from several consecutive breaths. Diaphragmatic electromyograms from a human and from a rabbit are processed in this manner, and the effect on the processed wave forms of changes in inspired CO2 and of a change in end-expiratory lung volume are demonstrated.
mesh_terms: D000818:Animals; D002245:Carbon Dioxide; D003201:Computers; D003964:Diaphragm / Q000502:physiology*; D004576:Electromyography / Q000379:methods; D005105:Expiratory Reserve Volume; D006801:Humans; D011817:Rabbits
chemical_list: D002245:Carbon Dioxide