A new method for assessing flow-volume measurements by means of a simple isoflow electronic pocket device (IfloPen)

The IfloPen is a new device for measuring isoflows featuring specific information about the effort-independent part of the flow-volume curve. Whereas the recording of the latter normally requires expensive equipment, the IfloPen is a handy, portable and simple device. In addition, the isoflow technique requires minimal cooperation. Significant correlations have been found between the isoflow-points measured with the IfloPen and PF, MEF50, MEF25 and FEV1 (p < 0.001). The IfloPen showed better correlations with spirometric lung function data than with the Peak-flow-Meter. Even experimentally induced bronchial obstruction during a bronchial challenge with carbachol can be measured functionally by the IfloPen, showing similar changes as obtained by the FEV1 and the MEF50 (p < 0.001). From a practical point of view, the IfloPen features a new device to measure more accurately bronchial obstruction (no overestimation, physiological breathing maneuver, good practicability). It can therefore be used in medical practice and is a suitable device for home monitoring.