@misc{TopcuFruehwirthMoseretal.2018,
  author    = {Top{\c{c}}u, {\c{C}}ağda{\c{s}} and Fr{\"u}hwirth, Matthias and Moser, Maximilian and Rosenblum, Michael and Pikovskij, Arkadij},
  title     = {Disentangling respiratory sinus arrhythmia in heart rate variability records},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {913},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43631},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-436315},
  pages     = {15},
  year      = {2018},
  abstract  = {Objective: Several different measures of heart rate variability, and particularly of respiratory sinus arrhythmia, are widely used in research and clinical applications. For many purposes it is important to know which features of heart rate variability are directly related to respiration and which are caused by other aspects of cardiac dynamics. Approach: Inspired by ideas from the theory of coupled oscillators, we use simultaneous measurements of respiratory and cardiac activity to perform a nonlinear disentanglement of the heart rate variability into the respiratory-related component and the rest. Main results: The theoretical consideration is illustrated by the analysis of 25 data sets from healthy subjects. In all cases we show how the disentanglement is manifested in the different measures of heart rate variability. Significance: The suggested technique can be exploited as a universal preprocessing tool, both for the analysis of respiratory influence on the heart rate and in cases when effects of other factors on the heart rate variability are in focus.},
  language  = {en}
}
@misc{FreitagWeberSandersetal.2018,
  author    = {Freitag, Nils and Weber, Pia Deborah and Sanders, Tanja Christiane and Schulz, Holger and Bloch, Wilhelm and Schumann, Moritz},
  title     = {High-intensity interval training and hyperoxia during chemotherapy},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {453},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414112},
  pages     = {7},
  year      = {2018},
  abstract  = {Introduction: We conducted a case study to examine the feasibility and safety of high-intensity interval training (HIIT) with increased inspired oxygen content in a colon cancer patient undergoing chemotherapy. A secondary purpose was to investigate the effects of such training regimen on physical functioning. Case presentation: A female patient (51 years; 49.1 kg; 1.65 m; tumor stage: pT3, pN2a (5/29), pM1a (HEP), L0, V0, R0) performed 8 sessions of HIIT (5 × 3 minutes at 90\% of Wmax, separated by 2 minutes at 45\% Wmax) with an increased inspired oxygen fraction of 30\%. Patient safety, training adherence, cardiorespiratory fitness (peak oxygen uptake and maximal power output during an incremental cycle ergometer test), autonomous nervous function (i.e., heart rate variability during an orthostatic test) as well as questionnaire-assessed quality of life (EORTC QLQ-C30) were evaluated before and after the intervention. No adverse events were reported throughout the training intervention and a 3 months follow-up. While the patient attended all sessions, adherence to total training time was only 51\% (102 of 200 minutes; mean training time per session 12:44 min:sec). VO2peak and Wmax increased by 13\% (from 23.0 to 26.1 mL min kg-1) and 21\% (from 83 to 100 W), respectively. Heart rate variability represented by the root mean squares of successive differences both in supine and upright positions were increased after the training by 143 and 100\%, respectively. The EORTC QLQ-C30 score for physical functioning (7.5\%) as well as the global health score (10.7\%) improved, while social function decreased (17\%). Conclusions: Our results show that a already short period of HIIT with concomitant hyperoxia was safe and feasible for a patient undergoing chemotherapy for colon cancer. Furthermore, the low overall training adherence of only 51\% and an overall low training time per session (∼13 minutes) was sufficient to induce clinically meaningful improvements in physical functioning. However, this case also underlines that intensity and/or length of the HIIT-bouts might need further adjustments to increase training compliance.},
  language  = {en}
}