摘要 |
A method and apparatus are shown for monitoring respiration volumes by continuously measuring, while the patient breathes, variations in the patient's chest cross sectional area, or preferably, variations in both chest and abdomen areas. Each area is measured by measuring the inductance of an extensible electrical conductor closely looped around the body, by connecting the loop as the inductance in a variable frequency LC oscillator followed by a frequency-to-voltage converter and a voltage display. Calibration is made by measuring the area variations for a few breaths while directly measuring corresponding volumes of breath, preferably while the patient assumes at least two body positions, for example sitting and supine. The method and apparatus may also be used to monitor changes in area of any non-magnetic object.
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