Low latency breathing frequency detection and monitoring on a personal computer

J Med Eng Technol. 2011 Aug-Oct;35(6-7):322-9. doi: 10.3109/03091902.2011.591481. Epub 2011 Jul 18.


We demonstrate a low latency respiratory/breathing frequency detection system that is fast (<5 ms), easy to operate, requires no batteries or external power supply and operates fully via computer-standard USB connection. Exercises in controlling ones breathing frequency, usually referred to as paced-breathing exercises, have shown positive effects in treating pulmonary diseases, cardiovascular diseases and stress/anxiety-related disorders. We developed a breathing frequency detection system which uses two pairs of microphones to detect exhalation activity, eliminate noise from the environment and stream the recording data via USB connection to a personal computer. It showed 97.1% reliability (10 subjects) when monitoring breathing activity in non-guided free breathing and 100% reliability (10 subjects) when monitoring breathing activity during interactive paced-breathing exercises. We also evaluated the breathing frequency detection systems noise elimination functionality which showed a reduction of 84.2 dB for stationary (white noise) and a reduction of 79.3 dB for non-stationary (hands clapping) noise.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Algorithms
  • Breathing Exercises
  • Equipment Design
  • Female
  • Humans
  • Male
  • Microcomputers*
  • Middle Aged
  • Monitoring, Physiologic / instrumentation*
  • Monitoring, Physiologic / methods
  • Respiratory Mechanics / physiology*
  • Sensitivity and Specificity
  • Signal Processing, Computer-Assisted / instrumentation*
  • Software