NSRR staff
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We generally remove calendar dates from all our files since they are considered identifiers. This does pose difficulties in aligning some data, such as the MESA PSG and actigraphy files.
There is a section on this page that describes the overlap between MESA PSG and actigraphy data - https://www.sleepdata.org/datasets/mesa/pages/actigraphy-introduction.md
I believe you could use that supplemental file, along with the HRV **seconds **column (https://www.sleepdata.org/datasets/mesa/pages/hrv-analysis.md), to align these data sources (when they overlapped, which was not the case for some subjects).
Thanks for the suggestion - I agree raw accelerometry data will be helpful to researchers. Unfortunately, the device used in MESA and HCHS - the Philips Actiwatch Spectrum - does not output raw accelerometry data. It only outputs activity/light data into binned epochs, e.g. 30 seconds. For future datasets with accelerometry data we plan to make those data available for download.
Thanks for checking out the site. In SHHS, HRV analysis was only performed during sleep time. From https://sleepdata.org/datasets/shhs/pages/13-hrv-analysis.md:
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summary (Entire night) - Analysis is performed from sleep onset to sleep termination. This analysis requires the following information: the time of occurrence of each R-wave, and the sleep onset and termination times. These times were extracted from the file containing the sleep stage annotations as the first and last 30 sec episode of stage 1, 2, 3 or 5 (REM), respectively. RR intervals larger than 2.5 seconds were excluded from the analysis.
Thanks for your interest in the site. From https://sleepdata.org/about/
The NSRR Data Access Committee reviews incoming data requests and responds to them within 1-2 weeks of submission.
Thanks - I saw your question. I referred it to another team member to comment first.
I'm very confused about how to use the dataset. Can you give me some advice about how to use it correctlly?
Note the "Known Issues" for SHHS, if you haven't already: https://sleepdata.org/datasets/shhs/pages/05-polysomnography-introduction.md
In addition to linking desaturations there may be other quirks with events that either 1) start in sleep and end in wake, or 2) start in wake and end in sleep.
You won't find as many of these discrepancies in newer datasets.
The "hard" part, I think, would be reverse engineering the linking of desaturations with hypopneas. I'm not sure what sort of time windows before/after the respiratory event that the scoring software used. You might play around with your detection.
You could add up the total number of events of each type and then compare them with the numerator of ahi_a0h3 - https://sleepdata.org/datasets/shhs/variables/ahi_a0h3
For instance, carbp + carop + canbp + canop should be the total number of central apneas. There is another set of variables for obstructive apneas, and another for hypopneas with >=3% desaturation.
Good question - unfortunately the Profusion scoring software did not make this straightforward because it does not always output metadata about each respiratory event, such as "associated with a desaturation of X%" and/or "associated with an arousal". It would be up to you (the user) to try and piece this together.
Thanks for using the site.
Thanks for checking out the site. Unfortunately I don't think anyone on the NSRR team is familiar with the Morpheus recorder.
Thanks for using the NSRR.
Please read through the available MESA documentation, e.g. the PSG Manual of Procedures (https://sleepdata.org/datasets/mesa/files/documentation/MESA_Sleep_Actigraphy_Manual_of_Procedures.pdf) and equipment overview (https://sleepdata.org/datasets/mesa/pages/equipment), and let us know if you have specific questions.