Calibrating Respiratory Strain Gauges: What the Numbers Mean for Monitoring Respiration
How can you be sure that a larger abdominal waveform, as compared with a smaller chest waveform, means that a client is breathing more abdominally than thoracically? Could this difference be due to discrepancies in the sensitivity of the sensors? This article describes a procedure for measuring the sensitivity of respiratory strain gauges and provides practical recommendations for accurate measurement and display of the relative expansion and contraction of the chest and abdomen.
Location of thoracic and abdominal respiratory strain gauges.
One-minute recording of respiration in which the subject breathes more thoracically (indicated by the larger amplitude of the black thoracic tracing and the ratio of the abdominal/thoracic standard deviations: 3.34/4.40 = 0.76).
Measuring the stretch of a strain gauge with a ruler.
Basic calibration procedure to measure relative units of stretch of respiration strain gauges.
Comparison of the sensitivity of respiratory sensors (relative units of stretch/millimeter).
Erik Peper
Grant Groshans
Richard Harvey
Fred Shaffer
Contributor Notes