An estimated 45 million persons in Europe are annually subjected to sleep-wake disorders. State-of-the-art polysomnography provides sophisticated insights into sleep (patho)physiology. A drawback of the method, however, is the obtrusive setting dependent on a clinical-based sleep laboratory with high operational costs. A contact-less prototype was developed to monitor limb movements and vital signs during sleep. A dual channel K-band Doppler radar transceiver captured limb movements and periodic chest wall motion due to respiration and heart activity. A wavelet transform based multi-resolution analysis (MRA) approach isolated limb movements, respiration, and heart rate from the demodulated signal. A test bench setup characterized the prototype simulating near physiological chest wall motions caused by periodic respiration and heartbeats in humans. Single- and multi-tone test bench simulations showed extremely low relative percentage errors of the prototype for respiratory and heart rate within -2 and 1%. The performance of the prototype was validated in overnight comparative studies, involving two healthy volunteers, with polysomnography as the reference. The prototype has successfully classified limb movements, with a sensitivity and specificity of 88.9 and 76.8% respectively, and has achieved accurate respiratory and heart rate measurement performance with overall absolute errors of 1 breath per minute for respiration and 3 beats per minute for heart rate. This pilot study shows that K-band Doppler radar and wavelet transform MRA seem to be valid for overnight sleep marker assessment. The contact-less approach might offer a promising solution for home-based sleep monitoring and assessment.

We successfully demonstrated the feasibility of our system to measure the acetabular orientation during PAO.

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) therapy is a rescue strategy for severe cardiopulmonary failure. The estimation of cardiac output during VA-ECMO is challenging. A lung circuit ($${\dot{\text{Q}}}$$ Q ˙ Lung) and an ECMO circuit ($${\dot{\text{Q}}}$$ Q ˙ ECMO) with oxygenators for CO2 removal ($$\mathop {\text{V}}\limits^{.}$$ V . CO2) and O2 uptake ($$\mathop {\text{V}}\limits^{.}$$ V . O2) simulated the setting of VA-ECMO with varying ventilation/perfusion ($$\mathop {\text{V}}\limits^{.}$$ V . /$${\dot{\text{Q}}}$$ Q ˙ ) ratios and shunt. A metabolic chamber with a CO2/N2 blend simulated $$\mathop {\text{V}}\limits^{.}$$ V . CO2 and $$\mathop {\text{V}}\limits^{.}$$ V . O2. $${\dot{\text{Q}}}$$ Q ˙ Lung was estimated with a modified Fick principle: $${\dot{\text{Q}}}$$ Q ˙ Lung = $${\dot{\text{Q}}}$$ Q ˙ ECMO × ($$\mathop {\text{V}}\limits^{.}$$ V . CO2 or $$\mathop {\text{V}}\limits^{.}$$ V . O2Lung)/($$\mathop {\text{V}}\limits^{.}$$ V . CO2 or $$\mathop {\text{V}}\limits^{.}$$ V . O2ECMO). A normalization procedure corrected $$\mathop {\text{V}}\limits^{.}$$ V . CO2 values for a $$\mathop {\text{V}}\limits^{.}$$ V . /$${\dot{\text{Q}}}$$ Q ˙ of 1. Method agreement was evaluated by Bland–Altman analysis. Calculated $${\dot{\text{Q}}}$$ Q ˙ Lung using gaseous $$\mathop {\text{V}}\limits^{.}$$ V . CO2 and $$\mathop {\text{V}}\limits^{.}$$ V . O2 correlated well with measured $${\dot{\text{Q}}}$$ Q ˙ Lung with a bias of 103 ml/min [− 268 to 185] ml/min; Limits of Agreement: − 306 ml/min [− 241 to − 877 ml/min] to 512 ml/min [447 to 610 ml/min], r2 0.85 [0.79–0.88]). Blood measurements of $$\mathop {\text{V}}\limits^{.}$$ V . CO2 showed an increased bias (− 260 ml/min [− 1503 to 982] ml/min), clinically not applicable. Shunt and $$\mathop {\text{V}}\limits^{.}$$ V . /$${\dot{\text{Q}}}$$ Q ˙ mismatch decreased the agreement of methods significantly. This in-vitro simulation shows that $$\mathop {\text{V}}\limits^{.}$$ V . CO2 and $$\mathop {\text{V}}\limits^{.}$$ V . O2 in steady-state conditions allow for clinically applicable calculations of $${\dot{\text{Q}}}$$ Q ˙ Lung during VA-ECMO therapy.