Ambulatory impedance pneumography device for quantitative monitoring of volumetric parameters in respiratory and cardiac applications

The estimation of respiratory flow and volume parameters is difficult to perform and uncomfortable for the patient during long-term monitoring outside the clinical environment. It is also hard to perform during sleep due to the usage of a facemask. The impedance pneumography (IP) device allows monitoring of breathing activity, estimates the respiratory rate and provides the quantitative measurements of the static and dynamic respiratory parameters, e.g. tidal volume (TV) or peak expiratory flow (PEF). A miniaturized, Holter-type impedance pneumography device, Pneumonitor, with analog output and intrinsic digital memory, was designed and constructed. The system allows long-term assessment of ventilation by measuring changes in thoracic impedance using the tetrapolar method.