An easily calibrated circumferential respiratory effort transducer with low mechanical load and medium impedance

An open circumferential gauge for monitoring respiratory effort that has the advantage of allowing calibration of absolute length is discussed. There is no known toxicity from the contents of the gauge. Since it has the properties of precision as in an Hg-in-silastic gauge without the toxic content as well as a long service life, it may prove to be an effective respiratory transducer. Two gauges have the potential of accurately reflecting the interactive effects of airway obstruction at the chest and abdomen