Heart rate variability evaluation of Emfit sleep mattress breathing categories in NREM sleep  Mirja Tenhunen, Jari Hyttinen, Jukka A. Lipponen, Jussi Virkkala, Sonja Kuusimäki, Mika P. Tarvainen, Pasi A. Karjalainen, Sari-Leena Himanen  Clinical Neurophysiology  Volume 126, Issue 5, Pages 967-974 (May 2015) DOI: 10.1016/j.clinph.2014.08.012 Copyright © 2014 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 1 Photograph of the Emfit mattress and the Static Charge Sensitive Bed (SCSB). In the figure the smaller, rectangular Emfit mattress is placed on the full bed sized SCSB for comparison. During the night the Emfit mattress is covered with an ordinary foam mattress and sheet. Clinical Neurophysiology 2015 126, 967-974DOI: (10.1016/j.clinph.2014.08.012) Copyright © 2014 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 2 Examples of 3-min epochs of different breathing categories. Traces from top to bottom: nasal flow, oesophageal pressure, respiratory movements by Emfit mattress, high frequency trace of Emfit, heart rate variation, oxygen saturation. The figures are from the same male subject suffering from sleep apnea and sustained partial obstruction. The scale of the traces is equal in all. (a) Normal breathing (NB) with regular respiration, no respiratory events, normal intrathoracal pressure, no high frequency spikes, moderate heart rate variation, no desaturations. (b) Periodic obstructive breathing (POB) with obstructive apneas, oesophageal pressure swings, periodic breathing with periodic high frequency spikes on Emfit traces, clear heart variation and desaturations. (c) Increased respiratory resistance (IRR) with regular breathing, increased negative intrathoracal pressure, regular breathing with continuous high frequency spikes on Emfit traces, moderate heart rate variation, no desaturations. Clinical Neurophysiology 2015 126, 967-974DOI: (10.1016/j.clinph.2014.08.012) Copyright © 2014 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 2 Examples of 3-min epochs of different breathing categories. Traces from top to bottom: nasal flow, oesophageal pressure, respiratory movements by Emfit mattress, high frequency trace of Emfit, heart rate variation, oxygen saturation. The figures are from the same male subject suffering from sleep apnea and sustained partial obstruction. The scale of the traces is equal in all. (a) Normal breathing (NB) with regular respiration, no respiratory events, normal intrathoracal pressure, no high frequency spikes, moderate heart rate variation, no desaturations. (b) Periodic obstructive breathing (POB) with obstructive apneas, oesophageal pressure swings, periodic breathing with periodic high frequency spikes on Emfit traces, clear heart variation and desaturations. (c) Increased respiratory resistance (IRR) with regular breathing, increased negative intrathoracal pressure, regular breathing with continuous high frequency spikes on Emfit traces, moderate heart rate variation, no desaturations. Clinical Neurophysiology 2015 126, 967-974DOI: (10.1016/j.clinph.2014.08.012) Copyright © 2014 International Federation of Clinical Neurophysiology Terms and Conditions

Fig. 2 Examples of 3-min epochs of different breathing categories. Traces from top to bottom: nasal flow, oesophageal pressure, respiratory movements by Emfit mattress, high frequency trace of Emfit, heart rate variation, oxygen saturation. The figures are from the same male subject suffering from sleep apnea and sustained partial obstruction. The scale of the traces is equal in all. (a) Normal breathing (NB) with regular respiration, no respiratory events, normal intrathoracal pressure, no high frequency spikes, moderate heart rate variation, no desaturations. (b) Periodic obstructive breathing (POB) with obstructive apneas, oesophageal pressure swings, periodic breathing with periodic high frequency spikes on Emfit traces, clear heart variation and desaturations. (c) Increased respiratory resistance (IRR) with regular breathing, increased negative intrathoracal pressure, regular breathing with continuous high frequency spikes on Emfit traces, moderate heart rate variation, no desaturations. Clinical Neurophysiology 2015 126, 967-974DOI: (10.1016/j.clinph.2014.08.012) Copyright © 2014 International Federation of Clinical Neurophysiology Terms and Conditions