Introduction Impedance cardiography is a noninvasive technique for monitoring the changes in the electrical impedance of the thorax z(t), caused by variation in the blood volume during the cardiac cycle [1]. Time derivative of the thoracic impedance is known as the impedance cardiogram (ICG) and it is used for estimating the ventricular ejection time (Tlvet), the negative peak of ICG ((-dz/dt)m...

This study aimed to implement low-frequency forced oscillation technique (LFFOT) in neonatal total liquid ventilation (TLV) and to provide the first insight into respiratory impedance under this new modality of ventilation. Thirteen newborn lambs, weighing 2.5 + or - 0.4 kg (mean + or - SD), were premedicated, intubated, anesthetized, and then placed under TLV using a specially design liquid ve...

Newborn rabbits were rendered acutely anoxic by insertion into an atmosphere of nitrogen and their respiratory movements were recorded by direct observation and by an impedance pneumograph. The respiratory response comprised periods of dyspnoea, preterminal apnoea, gasping, and terminal apnoea. The duration of preterminal apnoea was increased at the expense of the period of gasping by the prior...

The identification of respiratory impedance based on mathematical models and the consequent assessment of respiratory work propose an aid to adequately setting ventilatory support. We compared the respiratory models RC, RIC, eRC, eRIC, aRC and aRIC using parametric identification by ARX, ARMAX and OE and data from simulations, volunteers and patients. The comparison bases on the quality of the ...

Background It is well known that increased airflow limitation as measured by spirometry is associated with the risk of exacerbation in patients with COPD. The forced oscillation technique (FOT) is a noninvasive method used to assess respiratory impedance (resistance and reactance) with minimal patient cooperation required. The clinical utility of the FOT in assessing the risk of exacerbations o...

Details are given of the results obtained from anaesthetized patients when an electrical impedance pneumograph was used to continuously monitor respiratory pattern. The method was convenient to use, and faithfully followed changes in pattern. It is necessary to calibrate each patient initially against a spirometer or syringe. The impedance pneumograph is particularly useful when a number of phy...

INTRODUCTION Automatic ventilation for patients with respiratory failure aims at reducing mortality and can minimize the workload of clinical staff, offer standardized continuous care, and ultimately save the overall cost of therapy. We therefore developed a prototype for closed-loop ventilation using acute respiratory distress syndrome network (ARDSNet) protocol, called autoARDSNet. METHODS ...

The aim of the present study was to determine reference values and predictive variables for respiratory impedance (Zrs) by the forced oscillation technique (FOT) in subjects aged>65 yrs. The investigation involved a prospective study of nonsmoking subjects, with normal forced expiratory volumes. The Zrs parameters, which included average resistance between 4-16 Hz (R4-16), average resistance be...