Fig. 3: Study schematic and CONSORT diagram for Benchmarking Study and Replication Study.

a, The Benchmarking Study conducted at The Villages was designed to define the relationship between parenchymal resistance (R_P) and glymphatic function. Reported here are the overnight and morning device recordings, overnight and morning gold-standard PSG, and morning CE-MRI following intravenous GBCA administration as a measure of glymphatic function. Primary and secondary outcome data not reported here included blood analysis of amyloid β and tau levels, cognitive assessment and non-contrast MRI. b, The Replication Study conducted at the University of Washington had a primary outcome of confirming the effect of sleep state on device-measured R_P, and secondary outcomes of confirming the associations between R_P and sleep stages, heart rate and EEG spectral band power. The Replication Study also included secondary outcomes on blood analyses for amyloid β and tau levels, cognitive assessment and non-contrast MRI. c, The Benchmarking Study enrolled 34 participants of which 30 completed both visits. Three were censored due to changes in device data collection and sensor locations. One withdrew following the first MRI scan. Of the 30 that completed the study, 5 overnight sleep visits and 8 overnight wake visits failed the data quality control (QC) criteria to provide sufficient artefact-free data to yield results. This resulted in 25 sleep and 22 wake device, PSG and MRI complete datasets. Of these, 20 sleep and 21 wake device participants had complete data from both the overnight and morning sleep/wake periods. The Replication Study enrolled 14 participants. All 14 completed the study, of which 2 wake visits failed the data QC criteria and no sleep visit failed. Sleep op, sleep opportunity.