Assessment of the parameters of human external respiration by means of a portable volumeter under the field and laboratory conditions

Spirometric assessment of human lung capacity is usually feasible only under laboratory conditions, using expensive equipment, bicycle ergometers, or treadmills. Hence, it is desirable to develop a portable device to measure the key parameters of the external respiration of a subject under field conditions, with the data saved in the memory on a breath-by-breath basis and then transferred to a computer for further analysis. We have created a portable device consisting of an easy and tiny sensor fastened to a respiratory mask. The sensor is connected with a cable to a tiny device with an LCD screen where the values of pulmonary ventilation ( Ve ), expiratory volume ( Vt ), and respiratory rate are shown in turn by the choice of the operator. Metrological studies have shown that the instrument error generally did not exceed 5%.