The Virtual Sleep Lab-A Novel Method for Accurate Four-Class Sleep Staging Using Heart-Rate Variability from Low-Cost Wearables.

Sleep staging based on polysomnography (PSG) performed by human experts is the de facto "gold standard" for the objective measurement of sleep. PSG and manual sleep staging is, however, personnel-intensive and time-consuming and it is thus impractical to monitor a person's sleep architecture over extended periods. Here, we present a novel, low-cost, automatized, deep learning alternative to PSG sleep staging that provides a reliable epoch-by-epoch four-class sleep staging approach (Wake, Light [N1 + N2], Deep, REM) based solely on inter-beat-interval (IBI) data. Having trained a multi-resolution convolutional neural network (MCNN) on the IBIs of 8898 full-night manually sleep-staged recordings, we tested the MCNN on sleep classification using the IBIs of two low-cost (

From Pulses to Sleep Stages: Towards Optimized Sleep Classification Using Heart-Rate Variability.

More and more people quantify their sleep using wearables and are becoming obsessed in their pursuit of optimal sleep ("orthosomnia"). However, it is criticized that many of these wearables are giving inaccurate feedback and can even lead to negative daytime consequences. Acknowledging these facts, we here optimize our previously suggested sleep classification procedure in a new sample of 136 self-reported poor sleepers to minimize erroneous classification during ambulatory sleep sensing. Firstly, we introduce an advanced interbeat-interval (IBI) quality control using a random forest method to account for wearable recordings in naturalistic and more noisy settings. We further aim to improve sleep classification by opting for a loss function model instead of the overall epoch-by-epoch accuracy to avoid model biases towards the majority class (i.e., "light sleep"). Using these implementations, we compare the classification performance between the optimized (loss function model) and the accuracy model. We use signals derived from PSG, one-channel ECG, and two consumer wearables: the ECG breast belt Polar® H10 (H10) and the Polar® Verity Sense (VS), an optical Photoplethysmography (PPG) heart-rate sensor. The results reveal a high overall accuracy for the loss function in ECG (86.3 %, κ = 0.79), as well as the H10 (84.4%, κ = 0.76), and VS (84.2%, κ = 0.75) sensors, with improvements in deep sleep and wake. In addition, the new optimized model displays moderate to high correlations and agreement with PSG on primary sleep parameters, while measures of reliability, expressed in intra-class correlations, suggest excellent reliability for most sleep parameters. Finally, it is demonstrated that the new model is still classifying sleep accurately in 4-classes in users taking heart-affecting and/or psychoactive medication, which can be considered a prerequisite in older individuals with or without common disorders. Further improving and validating automatic sleep stage classification algorithms based on signals from affordable wearables may resolve existing scepticism and open the door for such approaches in clinical practice.

Extravascular compared to Intravascular Femoral Closure is Associated with Less Bleeding and Similar MACE after Percutaneous Coronary Intervention.

Background: Various types of vascular closure devices (VCDs) are frequently utilized in patients undergoing percutaneous coronary intervention (PCI) in order to prevent arterial access site bleeding, which represents one of the most relevant complications associated with adverse clinical outcomes. This study aims to compare directly two mechanistically different types of femoral closure (FC) devices in patients undergoing PCI. Methods: This single-center, prospective, observational study includes consecutively patients either treated by the extravascular StarClose SE® (Abbott, Illinois, U.S.A.) or the intravascular AngioSeal™ FC (St. Jude Medical, Inc., St. Paul, MN, U.S.A.) after PCI. The primary endpoint was bleeding complications, the secondary endpoint was major adverse cardiac events (MACE) at 30 days of follow-up. Results: 200 patients in each group (StarClose SE® and AngioSeal™) were enrolled following PCI. The rates of overall and non-access site bleedings were significantly higher in the AngioSeal™ group (56%; 6%) compared to the StarClose SE® group (43.5%; 0.5%) (p = 0.012; 0.003). Additionally, complicated access site bleedings were also significantly higher in the AngioSeal™ group (p = 0.011). No significant differences of MACE were observed in both groups. However, there was a higher rate of unsuccessful implantation of the StarClose SE® (n=12, excluded from the study). Conclusions: In case of successful implantation, FC by the AngioSeal™ is associated with the higher rate of both access and non-access site bleedings, but similar rates of MACE at 30 days compared to the StarClose SE® device.

Spectral imaging enables contrast agent-free real-time ischemia monitoring in laparoscopic surgery.

Laparoscopic surgery has evolved as a key technique for cancer diagnosis and therapy. While characterization of the tissue perfusion is crucial in various procedures, such as partial nephrectomy, doing so by means of visual inspection remains highly challenging. We developed a laparoscopic real-time multispectral imaging system featuring a compact and lightweight multispectral camera and the possibility to complement the conventional surgical view of the patient with functional information at a video rate of 25 Hz. To enable contrast agent-free ischemia monitoring during laparoscopic partial nephrectomy, we phrase the problem of ischemia detection as an out-of-distribution detection problem that does not rely on data from any other patient and uses an ensemble of invertible neural networks at its core. An in-human trial demonstrates the feasibility of our approach and highlights the potential of spectral imaging combined with advanced deep learning-based analysis tools for fast, efficient, reliable, and safe functional laparoscopic imaging.

Differences of bleedings after percutaneous coronary intervention using femoral closure and radial compression devices.

Bleedings represent most relevant complications being correlated with significant rates of adverse clinical outcomes in patients undergoing percutaneous coronary intervention (PCI). To reduce bleeding and improve prognosis various types of vascular closure devices (VCD) are frequently applied. This study aims to compare directly one specific femoral closure (FC) to one specific radial compression (RC) device in patients after PCI focusing on overall and access-site bleedings as well as major adverse cardiac events (MACE).This single-center, prospective, and observational study included consecutive patients either treated by the FC (StarClose SE) or RC (TR Band) device following PCI. The primary outcome was bleeding; the secondary outcomes were MACE at 30 days of follow-up.Two hundred patients in each group were enrolled following PCI. Access-site bleeding was significantly higher in the FC (43%) compared to the RC (30%) group (P = .001). Most common type of access-site bleeding consisted of hematomas. Of these, small and large hematomas were significantly higher in the FC group (P < .05). No significant differences of MACE were observed in both groups. In multivariable logistic regression models no consistent significant association of any risk factor with bleeding complications was identified.Despite the use of VCD, transfemoral arterial access is still associated with a higher rates of access site bleeding consisting mostly of hematomas compared to trans-radial access, whereas no differences of MACE were observed between FC and RC patients at 30 days follow-up.