What is correction factor (CF):
The correction factor corrects any diluted breath sample if any excess O2% present in the breath
sample than required. For example, a good sample is considered to be an end tidal sample where the O2% should be low. If the sample is diluted, then it is corrected by the correction factor to give exact concentrations of H₂ and CH4 in the breath sample.
The correction factor corrects any diluted breath sample if any excess O2% present in the breath
sample than required. For example, a good sample is considered to be an end tidal sample where the O2% should be low. If the sample is diluted, then it is corrected by the correction factor to give exact concentrations of H₂ and CH4 in the breath sample.
Correction factor (CF) applied after bump testing the device with calibration gas:
After bump testing the device with the calibration gas, the final results need to be divided by the
correction factor (CF - 2.33) (press the '?' icon to see the CF) and the final result should be within +/- 10% tolerance of the gas concentration used. For example, if you use 100ppm H₂ & CH4 gas then the final result should be between 90ppm - 110ppm for both H₂ & CH4 and the O2% should be 20.9% (+/- 1%).
Correction factor (CF) applied after the patient breath sample test:
Please note, the results obtained after the patient breath sample test are calculated with CF obtained from the test. If the patient has done the breath test correctly (O2% level in the breath sample is <15%) then the CF will be ‘1’. This means, if the patient's results are 10ppm H₂ & 20ppm CH4 and, if the test was good, then the CF will be 1 and the displayed readings will be 10ppm H₂ and 20ppm CH4.
If the patient breath test was good but did not exhale completely to get the end tidal sample or if the sample is diluted (O2% level in the breath sample is >15%) then the CF will be applied, and the CF value will differ based on the O2% readings on the device. Any readings < 15% O2 is considered a good end-tidal sample. The device will correct any readings above this to account for the sample dilution.
Discrepancy in the duration taken for certain patients to complete the breath test. While
some receive results quickly and others require an extended exhalation period before
obtaining their results:
Please note, there is no fixed time for the breath sample test to complete, as it depends on patients’ breath sample accumulated during the test. The breath sample test ends automatically based on how long patients take to provide a good sample (reaching the O2 level < 15%). Once the O2 level in the breath sample reached to < 15% which means a good sample from the patient breath test has been accumulated, then the arrow will turn green and after 3sec the test ends itself. If the O2 level is > 15%, the device will not end the test itself and if the patient is struggling to exhale then the test can be ended manually by pressing the END button on the screen and then the results will be displayed.
To see a video of a breath test being performed, please see this YouTube video: