@article{HelmerHelfSammethetal.2022,
  author    = {Helmer, Philipp and Helf, Daniel and Sammeth, Michael and Winkler, Bernd and Hottenrott, Sebastian and Meybohm, Patrick and Kranke, Peter},
  title     = {The use of non-invasive continuous blood pressure measuring (ClearSight\(^®\)) during central neuraxial anaesthesia for caesarean section — a retrospective validation study},
  series = {Journal of Clinical Medicine},
  volume    = {11},
  journal   = {Journal of Clinical Medicine},
  number    = {15},
  issn      = {2077-0383},
  doi       = {10.3390/jcm11154498},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286042},
  year      = {2022},
  abstract  = {Background: The close monitoring of blood pressure during a caesarean section performed under central neuraxial anaesthesia should be the standard of safe anaesthesia. As classical oscillometric and invasive blood pressure measuring have intrinsic disadvantages, we investigated a novel, non-invasive technique for continuous blood pressure measuring. Methods: In this monocentric, retrospective data analysis, the reliability of continuous non-invasive blood pressure measuring using ClearSight\(^®\) (Edwards Lifesciences Corporation) is validated in 31 women undergoing central neuraxial anaesthesia for caesarean section. In addition, patients and professionals evaluated ClearSight\(^®\) through questioning. Results: 139 measurements from 11 patients were included in the final analysis. Employing Bland-Altman analyses, we identified a bias of -10.8 mmHg for systolic, of -0.45 mmHg for diastolic and of +0.68 mmHg for mean arterial blood pressure measurements. Pooling all paired measurements resulted in a Pearson correlation coefficient of 0.7 for systolic, of 0.67 for diastolic and of 0.75 for mean arterial blood pressure. Compensating the interindividual differences in linear regressions of the paired measurements provided improved correlation coefficients of 0.73 for systolic, of 0.9 for diastolic and of 0.89 for mean arterial blood pressure measurements. Discussion: Diastolic and mean arterial blood pressure are within an acceptable range of deviation from the reference method, according to the Association for the Advancement of Medical Instrumentation (AAMI) in the patient collective under study. Both patients and professionals prefer ClearSight\(^®\) to oscillometric blood pressure measurement in regard of comfort and handling.},
  language  = {en}
}
@article{HelmerHottenrottRodemersetal.2022,
  author    = {Helmer, Philipp and Hottenrott, Sebastian and Rodemers, Philipp and Leppich, Robert and Helwich, Maja and Pryss, R{\"u}diger and Kranke, Peter and Meybohm, Patrick and Winkler, Bernd E. and Sammeth, Michael},
  title     = {Accuracy and Systematic Biases of Heart Rate Measurements by Consumer-Grade Fitness Trackers in Postoperative Patients: Prospective Clinical Trial},
  series = {Journal of Medical Internet Research},
  volume    = {24},
  journal   = {Journal of Medical Internet Research},
  number    = {12},
  doi       = {10.2196/42359},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299679},
  year      = {2022},
  abstract  = {Background: Over the recent years, technological advances of wrist-worn fitness trackers heralded a new era in the continuous monitoring of vital signs. So far, these devices have primarily been used for sports. Objective: However, for using these technologies in health care, further validations of the measurement accuracy in hospitalized patients are essential but lacking to date. Methods: We conducted a prospective validation study with 201 patients after moderate to major surgery in a controlled setting to benchmark the accuracy of heart rate measurements in 4 consumer-grade fitness trackers (Apple Watch 7, Garmin Fenix 6 Pro, Withings ScanWatch, and Fitbit Sense) against the clinical gold standard (electrocardiography). Results: All devices exhibited high correlation (r≥0.95; P<.001) and concordance (rc≥0.94) coefficients, with a relative error as low as mean absolute percentage error <5\% based on 1630 valid measurements. We identified confounders significantly biasing the measurement accuracy, although not at clinically relevant levels (mean absolute error<5 beats per minute). Conclusions: Consumer-grade fitness trackers appear promising in hospitalized patients for monitoring heart rate.},
  language  = {en}
}
@article{DongBoeppleThieletal.2023,
  author    = {Dong, Meng and B{\"o}pple, Kathrin and Thiel, Julia and Winkler, Bernd and Liang, Chunguang and Schueler, Julia and Davies, Emma J. and Barry, Simon T. and Metsalu, Tauno and M{\"u}rdter, Thomas E. and Sauer, Georg and Ott, German and Schwab, Matthias and Aulitzky, Walter E.},
  title     = {Perfusion air culture of precision-cut tumor slices: an ex vivo system to evaluate individual drug response under controlled culture conditions},
  series = {Cells},
  volume    = {12},
  journal   = {Cells},
  number    = {5},
  issn      = {2073-4409},
  doi       = {10.3390/cells12050807},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311030},
  year      = {2023},
  abstract  = {Precision-cut tumor slices (PCTS) maintain tissue heterogeneity concerning different cell types and preserve the tumor microenvironment (TME). Typically, PCTS are cultured statically on a filter support at an air-liquid interface, which gives rise to intra-slice gradients during culture. To overcome this problem, we developed a perfusion air culture (PAC) system that can provide a continuous and controlled oxygen medium, and drug supply. This makes it an adaptable ex vivo system for evaluating drug responses in a tissue-specific microenvironment. PCTS from mouse xenografts (MCF-7, H1437) and primary human ovarian tumors (primary OV) cultured in the PAC system maintained the morphology, proliferation, and TME for more than 7 days, and no intra-slice gradients were observed. Cultured PCTS were analyzed for DNA damage, apoptosis, and transcriptional biomarkers for the cellular stress response. For the primary OV slices, cisplatin treatment induced a diverse increase in the cleavage of caspase-3 and PD-L1 expression, indicating a heterogeneous response to drug treatment between patients. Immune cells were preserved throughout the culturing period, indicating that immune therapy can be analyzed. The novel PAC system is suitable for assessing individual drug responses and can thus be used as a preclinical model to predict in vivo therapy responses.},
  language  = {en}
}
@article{HelmerRodemersHottenrottetal.2023,
  author    = {Helmer, Philipp and Rodemers, Philipp and Hottenrott, Sebastian and Leppich, Robert and Helwich, Maja and Pryss, R{\"u}diger and Kranke, Peter and Meybohm, Patrick and Winkler, Bernd E. and Sammeth, Michael},
  title     = {Evaluating blood oxygen saturation measurements by popular fitness trackers in postoperative patients: a prospective clinical trial},
  series = {iScience},
  volume    = {26},
  journal   = {iScience},
  number    = {11},
  issn      = {2589-0042},
  doi       = {10.1016/j.isci.2023.108155},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349913},
  year      = {2023},
  abstract  = {Summary Blood oxygen saturation is an important clinical parameter, especially in postoperative hospitalized patients, monitored in clinical practice by arterial blood gas (ABG) and/or pulse oximetry that both are not suitable for a long-term continuous monitoring of patients during the entire hospital stay, or beyond. Technological advances developed recently for consumer-grade fitness trackers could—at least in theory—help to fill in this gap, but benchmarks on the applicability and accuracy of these technologies in hospitalized patients are currently lacking. We therefore conducted at the postanaesthesia care unit under controlled settings a prospective clinical trial with 201 patients, comparing in total >1,000 oxygen blood saturation measurements by fitness trackers of three brands with the ABG gold standard and with pulse oximetry. Our results suggest that, despite of an overall still tolerable measuring accuracy, comparatively high dropout rates severely limit the possibilities of employing fitness trackers, particularly during the immediate postoperative period of hospitalized patients. Highlights •The accuracy of O2 measurements by fitness trackers is tolerable (RMSE ≲4\%) •Correlation with arterial blood gas measurements is fair to moderate (PCC = [0.46; 0.64]) •Dropout rates of fitness trackers during O2 monitoring are high (∼1/3 values missing) •Fitness trackers cannot be recommended for O2 measuring during critical monitoring},
  language  = {en}
}