Use of thoracic impedance sensors to screen for sleep-disordered breathing in patients with cardiovascular disease

Abstract

Screening patients for the possibility of sleep apnoea, one of the most common forms of sleep-disordered breathing, requires measurement of respiration. We propose a simple method to estimate the amplitude modulation of a respiratory tidal volume, using a semi-quantitative measure of respiration based on thoracic impedance (TI). Because respiratory volume changes may be accommodated by varying displacements of the rib cage (RC) and abdomen (AB), the latter produced by outward motion of the diaphragm, it is necessary for any useful measure of respiration to be closely related to both RC and AB displacements. Because the relative contributions of RC and AB displacements to respiratory tidal volume vary in different body positions, the present measurements were recorded from subjects in supine, and right and left lateral decubitus postures. We observed a clear linear relationship between TI and both RC and AB signals in all three body positions. There were no statistically significant differences between observed relationships between TI and AB and between TI and RC, and these relationships were independent of the body position. TI sensors appear to be a useful candidate for a simple method of screening for sleep apnoea, especially in a cardiology clinical setting. Further investigation is warranted for the refinement of algorithms to detect changes in amplitude modulation occurring with apnoeas and to remove artefacts due to gross body movements.

Recycling cardiogenic artifacts in impedance pneumography

“…We may, however, augment the filtering in [15] with one of two spectral methods to achieve an estimate for the IHR which rivals the dsSST approach. To show that the advantages of the dsSST include a cancellation of respiratory harmonics exceeding the threshold 0.5 Hz, we do the following.…”

Thoracic impedance, in association with oximetry, in a multi-modal ECG Holter system is useful for screening sleep disordered breathing

“…Efficacy of statins has been demonstrated in secondary prevention of acute coronary syndromes (ACS) even with normal lipid level [1,2]. Statins act in cardiovascular diseases as a lipid-lowering drug but have also pleiotropic effects [3]. Statins in randomized controlled studies in large primary prevention populations have no clear impact on total mortality [4].…”

“…To be well adapted to routine cardiology practice, development of a specific automatic analysis of this signal is necessary to limit time-consuming visual analysis. A new method, based on thoracic impedance (TI) sensors imbedded in multimodal electrocardiogram (ECG) Holter system has been proposed as a simple method of screening for SDB [2,3]. In this prospective study, we assessed TI alone and in association with oximetry in a multi-modal ECG Holter system with automatic analysis, by comparing it with the gold standard method, a simultaneous, in-hospital polysomnography (PSG), in a large population suspected of SDB.…”

Investigation of Obstructive Sleep Apnea Using Nonlinear Mode Interactions in Nonstationary Snore Signals

“…14 Hence, several researchers have attempted to propose techniques that could facilitate effective, convenient, and inexpensive mass screening for OSA. These techniques include, but are not limited to, analyzing heart rate variability, 24 thoracic movement, 43 and acoustical properties of snores. 1,2,8,11,17,19,22,30,37,38,40,46,47,53 Among these techniques, snore-based analysis has received growing interests as it can possibly offer safe and non-invasive data measurement with minimum labor and medical costs.…”