Zhou G, Karlen W, Brant R, Wiens M, Kissoon N, Ansermino JM. A transformation of oxygen saturation (the saturation virtual shunt) to improve clinical prediction model calibration and interpretation. Pediatric Research. 2019 Aug.; 3--10.      [DOI]      [File] 

Kammerer T, Faihs V, Hulde N, Bayer A, Hübner M, Brettner F, Karlen W, Kröpfl JM, Rehm M, Spengler C, Schäfer ST. Changes of hemodynamic and cerebral oxygenation after exercise in normobaric and hypobaric hypoxia: associations with acute mountain sickness. Annals of occupational and environmental medicine. 2018; 30(1):66.      [DOI]      [File] 

Scebba G, Dragas J, Hu S, Karlen W. Improving ROI detection in photoplethysmographic imaging with thermal cameras. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). Jeju Island, South Korea: 2017. p. 4285--88.      [DOI] 

Scebba G, Dragas J, Hu S, Karlen W. Thermal cameras enhance ROI detection in photoplethysmographic imaging. In: Annual Meeting of the Swiss Society for Biomedical Engineering (SSBE). Winterthur: 2017.

Ding X, Zhang Y, Tsang HK, Karlen W. A pulse transit time based fusion method for the noninvasive and continuous monitoring of respiratory rate. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE; 2016. p. 4240--3.      [DOI]      [File] 

Dunsmuir D, Garde A, Zhou G, Raihana S, Huda T, Karlen W, Dehkordi P, Arifeen SE, Ansermino JM. Analysis of the Predictive Potential of Pulse Oximeter Data for Admission. In: Proceedings of the 2016 Society for Technology in Anesthesia Annual Meeting. Anesthesia and analgesia; 2016. p. 75--76.

Garde A, Zhou G, Raihana S, Dunsmuir D, Karlen W, Dekhordi P, Huda T, Arifeen SE, Larson C, Kissoon N, Dumont GA, Ansermino JM. Respiratory rate and pulse oximetry derived information as predictors of hospital admission in young children in Bangladesh: a prospective observational study. BMJ Open. 2016; 6(8):e011094.      [DOI]      [File] 

Karlen W, Raihana S, Dumont GA, Ansermino JM. PPG quality evaluation reduces SpO2 variability in spot check readings. In: Innovations and Applications of Monitoring Perfusion, Oxygenation and Ventilation (IAMPOV) 2015. Tokyo, Japan: 2015 Oct..

Karlen W, Garde A, Myers D, Scheffer C, Ansermino JM, Dumont GA. Estimation of Respiratory Rate From Photoplethysmographic Imaging Videos Compared to Pulse Oximetry. IEEE Journal of Biomedical and Health Informatics. 2015; 19(4):1331--8.      [DOI]      [File] 

Dehkordi P, Garde A, Karlen W, Petersen CL, Ansermino JM, Dumont GA. Detrended fluctuation analysis of photoplethysmogram pulse rate intervals in sleep disordered breathing. In: 2014 IEEE Healthcare Innovation Conference (HIC). Seattle: IEEE Engineering in Medicine and Biology Society; 2014. p. 323--326.      [DOI]      [File] 

Garde A, Dehkordi P, Karlen W, Wensley D, Ansermino JM, Dumont GA. Development of a screening tool for sleep disordered breathing in children using the phone oximeter™. PLoS ONE. 2014; 9(11):e112959.      [DOI]      [File] 

Garde A, Karlen W, Dehkordi P, Ansermino JM, Dumont GA. Oxygen saturation resolution influences regularity measurements. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). Chicago: IEEE Engineering in Medicine and Biology Society; 2014. p. 2257--60.      [DOI]      [File] 

Karlen W, Garde A, Myers D, Scheffer C, Ansermino JM, Dumont GA. Respiratory Rate Assessment from Photoplethysmographic Imaging. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). Chicago,IL,USA: IEEE Engineering in Medicine and Biology Society; 2014. p. 5397--400.

Dehkordi P, Garde A, Karlen W, Wensley D, Ansermino JM, Dumont GA. Sleep Stage Classification in Children Using Photoplethysmogram Pulse Rate Variability. In: Computing in Cardiology (CinC). 2014. p. 297--300.

Crede S, Merwe G, Hutchinson J, Woods D, Karlen W, Lawn J. Where do pulse oximeter probes break?. Journal of clinical monitoring and computing. 2014; 28(3):309--14.      [DOI]      [File] 

Garde A, Karlen W, Dehkordi P, Wensley D, Ansermino JM, Dumont GA. Analysis of Oxygen Saturation in Children with Obstructive Sleep Apnea Using the Phone-Oximeter. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). Osaka: 2013. p. 2531--4.

Karlen W, Ansermino JM, Dumont GA, Scheffer C. Detection of the optimal region of interest for camera oximetry. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). Osaka: 2013. p. 2263--6.      [DOI]      [File] 

Karlen W, Raman S, Ansermino JM, Dumont GA. Multiparameter respiratory rate estimation from the photoplethysmogram. IEEE Transactions on Biomedical Engineering. 2013; 60(7):1946--53.      [DOI]      [File] 

Karlen W, Petersen C, Gow J, Ansermino JM, Dumont GA. Photoplethysmogram Processing Using An Adaptive Single Frequency Phase Vocoder Algorithm. In: Fred, A and Filipe, J and Gamboa, H, editors. BIOSTEC 2011, CCIS 273. Berlin Heidelberg: Springer-Verlag; 2013. p. 31--42.      [DOI]      [File] 

Karlen W. Pulse Oximeters on Mobile Phones for Rural Health Care. In: Sustainable Rural Health Research Day. Worcester, South Africa: 2013.

Dehkordi P, Garde A, Karlen W, Wensley D, Ansermino JM, Dumont GA. Pulse rate variability compared with heart rate variability in children with and without sleep disordered breathing. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). 2013. p. 6563--6.

Karlen W, Kobayashi K, Ansermino JM, Dumont GA. Photoplethysmogram signal quality estimation using repeated Gaussian filters and cross-correlation. Physiological Measurement. 2012 Sep.; 33(10):1617--29.      [DOI]      [File] 

Karlen W, Ansermino JM, Dumont G. Adaptive pulse segmentation and artifact detection in photoplethysmography for mobile applications. In: 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. San Diego: IEEE; 2012 Aug.. p. 3131--3134.      [DOI]      [File] 

Chandler JR, Cooke E, Petersen C, Karlen W, Froese N, Lim J, Ansermino JM. Pulse oximeter plethysmograph variation and its relationship to the arterial waveform in mechanically ventilated children. Journal of clinical monitoring and computing. 2012 Jun.; 26(3):145--51.      [DOI]      [File] 

Raman S, Brouse CJ, Karlen W, Dumont GA, Ansermino JM. A Data Fusion Approach for RR estimation from PPG (STA Engineering Challenge). In: Proceedings of the 2012 Society for Technology in Anesthesia Annual Meeting. West Palm Beach: 2012.