초록 ▼

A method and apparatus for accurately measuring respiratory flow, while the subject breathes, without using a mouthpiece, face mask or any device about the head. The rate of change of the circumference of the rib cage (chest) and the rate of change of the circumference of the abdomen are measured us

A method and apparatus for accurately measuring respiratory flow, while the subject breathes, without using a mouthpiece, face mask or any device about the head. The rate of change of the circumference of the rib cage (chest) and the rate of change of the circumference of the abdomen are measured using an extensible belt with series strips of piezoelectric film. The stress on the film produces an electric output proportional to the rate of application of stress when connected to a proper electronic amplifier. Calibration is performed by measuring the circumference changes while the subject performs an isovolume maneuver for several breaths or while the subject breathes through a pneumotachometer and mouthpiece at a variable rate for several breaths.

대표청구항 ▼

A method of measuring respiratory air flow comprising the steps of a. measuring the rate of change of abdomen circumference using an abdominal linear piezoelectric sensor, with said piezoelectric sensor being attached to an extensible abdominal belt by means of at least on non-electrically-conductiv

A method of measuring respiratory air flow comprising the steps of a. measuring the rate of change of abdomen circumference using an abdominal linear piezoelectric sensor, with said piezoelectric sensor being attached to an extensible abdominal belt by means of at least on non-electrically-conductive rivet, said linear piezoelectric sensor having an electrically-conductive coating on each side thereon, which coating on one side of said linear piezoelectric sensor is removed around said rivet, to provide an electrical output; b. measuring the rate of change of rib cage circumference using a rib cage linear piezoelectric sensor, with said piezoelectric sensor being attached to an extensible rib cage belt by means of at least one non-electrically-conductive rivet, said linear piezoelectric sensor having an electrically-conductive coating on each side thereon, which coating on one side of said linear piezoelectric sensor is removed around said rivet, to provide an electric output; c. weighting and summing the outputs of the rib cage and abdominal sensors so that the summed output represents total respiratory flow.