Electrical Impedance Tomography Measurements During Apnea Test in Patients With Suspected Brain Death

Apnea testing is the final decisive examination in the strictly regulated process of brain death assessment. There is no standardized method found in the literature for apnea testing except for the inspection of possible spontaneous chest movements. In addition, the test itself lasts for several minutes leading to the collapse of the lungs. Electrical impedance tomography (EIT) is a non-invasive, real-time monitoring technique, which is suitable for detecting changes in lung volumes during ventilation. With its help, one can examine the spontaneous initiation of inspiration, the development of atelectasis and the reopening of collapsed regions by mechanical ventilation. Furthermore, the apnea test provides for analysing the effect of changes in pulmonary perfusion on impedance in the absence of noise generated by ventilation.