Abstract: | According to the Standards IEC 60601-2-12:2001, and ISO 10651-1:1993, the delivered respiratory volume is measured on the basis of isothermal compliance value of a lung model. Meanwhile, actual compression/decompression into lung model is not isothermal but polytropic during calibration. Therefore, in medical practice standard calibration overestimates the respiratory volume of ventilated lungs. The alternative method of calibration and testing of channels suggested in this work does not require a priori information about lung stretchability. Determination of stretchability of a model contour as a parameter allowed the stretchability of lungs and respiratory volume to be calculated using the method suggested in this work based on measurement of volume of gas, discharged to the atmosphere through the gas exhaust port. |