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1	Camera-based photoplethysmography in an intraoperative setting Trumpp, Alexander, Lohr, Johannes, Wedekind, Daniel, Schmidt, Martin, Burghardt, Matthias, Heller, Axel R., Malberg, Hagen, Zaunseder, Sebastian 11 June 2018 (has links) (PDF) Background Camera-based photoplethysmography (cbPPG) is a measurement technique which enables remote vital sign monitoring by using cameras. To obtain valid plethysmograms, proper regions of interest (ROIs) have to be selected in the video data. Most automated selection methods rely on specific spatial or temporal features limiting a broader application. In this work, we present a new method which overcomes those drawbacks and, therefore, allows cbPPG to be applied in an intraoperative environment. Methods We recorded 41 patients during surgery using an RGB and a near-infrared (NIR) camera. A Bayesian skin classifier was employed to detect suitable regions, and a level set segmentation approach to define and track ROIs based on spatial homogeneity. Results The results show stable and homogeneously illuminated ROIs. We further evaluated their quality with regards to extracted cbPPG signals. The green channel provided the best results where heart rates could be correctly estimated in 95.6% of cases. The NIR channel yielded the highest contribution in compensating false estimations. Conclusions The proposed method proved that cbPPG is applicable in intraoperative environments. It can be easily transferred to other settings regardless of which body site is considered. Kamerabasierte Photoplethysmographie Intraoperatives Monitoring Fernüberwachung Level Set Methoden Räumliche Homogenität TU Dresden Publikationsfond Camera-based photoplethysmography Intraoperative monitoring Remote monitoring Level set methods Spatial homogeneity TU Dresden Publishing Fund ddc:610 rvk:XA 10000
2	Camera-based photoplethysmography in an intraoperative setting Trumpp, Alexander, Lohr, Johannes, Wedekind, Daniel, Schmidt, Martin, Burghardt, Matthias, Heller, Axel R., Malberg, Hagen, Zaunseder, Sebastian 11 June 2018 (has links) Background Camera-based photoplethysmography (cbPPG) is a measurement technique which enables remote vital sign monitoring by using cameras. To obtain valid plethysmograms, proper regions of interest (ROIs) have to be selected in the video data. Most automated selection methods rely on specific spatial or temporal features limiting a broader application. In this work, we present a new method which overcomes those drawbacks and, therefore, allows cbPPG to be applied in an intraoperative environment. Methods We recorded 41 patients during surgery using an RGB and a near-infrared (NIR) camera. A Bayesian skin classifier was employed to detect suitable regions, and a level set segmentation approach to define and track ROIs based on spatial homogeneity. Results The results show stable and homogeneously illuminated ROIs. We further evaluated their quality with regards to extracted cbPPG signals. The green channel provided the best results where heart rates could be correctly estimated in 95.6% of cases. The NIR channel yielded the highest contribution in compensating false estimations. Conclusions The proposed method proved that cbPPG is applicable in intraoperative environments. It can be easily transferred to other settings regardless of which body site is considered. info:eu-repo/classification/ddc/610 ddc:610
3	Theory and Numerics for Shape Optimization in Superconductivity / Theorie und Numerik für ein Formoptimierungsproblem aus der Supraleitung Heese, Harald 21 July 2006 (has links) No description available. 510 Mathematik Mathematics and Computer Science Supraleitung Randwertproblem Integralgleichungen Level Set Methoden Formoptimierung superconductivity boundary value problem integral equations level set methods shape optimization 31.80 33.06 31.76 electromagnetic theory: General}

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