Academic Article


  • 2011

The O2 uptake of firefighters working in hot and polluted environment is not known. The portable Metamax II might measure the O2 uptake of firefighters using a breathing apparatus. However, the Metamax requires an inspiration signal between two expirations to work properly. When a firefighter inspires from bottles with pressurised air, the inspired air cannot readily be passed through a metabolic analyser. Expired air is on the other hand released to the surroundings and may be sampled for further analyses. In addition, the Metamax II does not tolerate heat, and gases at the scene of fire may damage its delicate sensors. We have modified the Metamax II, producing an artificial inspiration signal after every expiration. We have also protected the instrument from heat at the scene of fire. Expired air was sampled from exercising subjects using a breathing apparatus. The Metamax II instrument was run in the normal and modified modes while the instrumentʼs reported O2 uptake was recorded. Control experiments showed that without an inspiration signal, the instrument did not work reliably. In a typical experiment the reported O2 uptake was only 50% of the true value. In further experiments an artificial inspiration signal was sent to the main...

Medbø, Jon Ingulf; Synnes, Ole Martin; Von Heimburg, Erna Dianne
Acta Kinesiologiae Universitatis Tartuensis 17: 117–130
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