110 likes | 177 Views
Explore how Electrodermal Activity (EDA) reveals unique sleep patterns. Analyze EDA storms during sleep, distinguish stages, and compare with traditional methods. Discover insights into sleep quality and disorders.
E N D
Toward a Taxonomy of Autonomic Sleep Patterns with Electrodermal Activity Akane Sano and Rosalind W. Picard, Massachusetts Institute of Technology Media Lab Affective Computing Group akanes@mit.edu
What is Electrodermal Activity? • Electrical measures of sweat gland activity • Index of sympathetic nervous activation • Classically, has been measured with wired and gelled electrodes on the skin • Our research group developed a dry electrode, wearable sensor for long-term ambulatory measurement
Electrodermal Activity (EDA) during sleep Q:Sympathetic nervous activity goes up during a day and goes down and get silent during sleep? A: No!!! High frequency “storm” patterns during sleep Why these storm patterns happen?
Measurement of Sleep Polysomnography (PSG) + measures EEG and more, provides 30 s epochs labeled as: Wake, NonREM (stage 1-3), and REM - expensive and obtrusive Actigraphy + less invasive than PSG, low cost - only measures movement Our EDA sensor + comfortable, same or lower cost than actigraphy + measures EDA, skin temperature and actigraphy -+ measures different patterns than traditional
Objectives • Evaluate EDA sleep patterns quantitatively from healthy groups • Understand what the changing patterns ofEDA mean in terms of traditional PSG. Experiments Collected EDA+motionduring sleep from healthy adults Total: 168nights
Analysis: sleep vs. wake Sleep and wake are discriminated from accelerometer data with standard zero-crossing and Cole’s function wake
Analysis: EDA storms during sleep • After low-pass filtering (0.4 Hz, 32nd order FIR filter), we detected “storm” regions during sleep, regions of EDA with a burst of peaks Storm epoch: > 3 peaks / 30-sec with the slope of each peak >0.09 micro Siemens/s Storm: Storm epochs that are adjacent or within 5 minutes of each other Example: 6 storms in one night of sleep * wake Raw EDA * EDA Storm
EDA vs. sleep stages from PSG EDA raw data Motion data EDA peaks Sleep Stage Wake is red
More than 90 % of EDA Storms occurred in SWS and NREM2 (N=7, one night each) One subject had storms below the threshold Portion of storm epochs in each category of sleep.
2/3 of nights had >= 1 storm 1/2 of nights had >= 2 storms Histogram of # of storms over night (168 nights)
Summary • We analyzed electrodermal activity from healthy subjects over 150 nights • More than 90 % of EDA storms occurred in SWS and NREM2 (N=7, one night each) • 2/3 of nights showed more than 1 EDA storm 1/2 of nights had more than 2 storms Next Steps • Needs more detail analysis with EEG and heart rates • Are they related with sleep quality/ Sleep disorders or Memory consolidation?