Hi Sharon. The CHAT studies do generally have a PPG signal. The montage information can be viewed at https://sleepdata.org/datasets/chat/pages/equipment/montage-and-sampling-rate-information.md. Note that these studies were collected across multiple data collection sites, so naming of the channel might differ between sites. There might also be the occasional study where the signal is missing if a site experienced equipment issues and was unable to collect the signal. For the NCH Sleep DataBank, the depositor of the data did not provide us with a full list of what was collected in each study, but I did take a look at about 10 randomly selected EDF files and did not see a PPG signal in any of the 10. Thanks, and please let us know if you have any other questions.
Hello. For your other 2 questions:
For #1--You are correct. If a study participant was not comfortable exposing the rib cage for the left lead placement on the lower rib location, the placement could be modified so that the electrode was placed at the left subclavicle location, resulting in ECG being recorded from LA-RA leads.
For #2--In the example you mentioned, I believe these are referring to the way the channels were named on the PSG recording. This mean the ECG lead on the left side of the body (ECG L) and the ECG lead on the right side (ECG R) of the body. These are not meant to represent formal lead names as you would think of when looking at 12-lead ECG data.
Hello. There were multiple names used for the airflow signal as described under the SENSORS section at https://sleepdata.org/datasets/shhs/pages/08-equipment-shhs1.md. Here is the info from that page:
Thermistry/Thermocouple: The original Compumedics triple thermister a Y shaped chassis with nasal and oral bead sensors, used for the first few months of the study connected to the side of the PIB using a lemo connector and used Channel 12 named “Airflow” on the collection montage. The Compumedics thermister was uncomfortable and replaced with ProTech thermister M325. This thermister used the "auxiliary" channel as designated on the PIB (Channel 17). Sites were asked to modify the montage and name Channel 17 “New Air” so scorers would be able to tell when Compumedic thermister was used versus the Protech thermister. Instructions were sent to the sites on how to modify the collection montage (add channel 17). It took several attempts for some sites to correctly name this channel and modify the montage. As a result, some studies have this channel 17 named: “NEW AIR”, “NEWAIR”, “AIRFLOW”, “airflow”, "new A/F", "New Air" and/or “AUX.”
The signals you mention all represent combined nasal and oral airflow, as both of the devices referenced (Compumedics and ProTech) had sensors that measured temperature change at the nose and in front of the mouth.
I hope this is helpful, and please let us know if you have additional questions.
Your comment about the more appropriate variables is correct. The OAHI and ahi_a0h4 variables would give3 all apneas regardless of desaturation and hypopnea events with at least a 4% desaturation. The rdi4p variable uses only events with a 4% desaturation. Regarding RERAs, those events were not scored when this study was performed. Hope this helps.
Susan--Thanks so much for sharing your knowledge (and wisdom)! We could not have done it without you!
The NSRR does not currently have any datasets with snore channel sampled at >300 Hz. Additionally, I believe the snore data captured is vibratory snore through either the pressure transducer or via an EMG snore sensor, depending on the study.
The National Sleep Research Resource is organizing a meeting with a group of Early Adopters to be held on October 9th, 2015 in Boston, MA, USA. We identify Early Adopters as members of the scientific community who have obtained access to the data on the repository and are employing those data for their scientific research. Also, we would like to welcome any potential new users of the datasets, who may be interested in using NSRR data for their studies. The purpose of this one-day meeting is to bring together a group of “hands on” participants to promote active interaction and collaboration and to provide feedback to improve the value of the NSRR.
Participants in the meeting will have the opportunity to present research in progress using NSRR data, or planned research using NSRR data, report technical bugs, signal anomalies and issues, to highlight tools they want to share, and to interact with the rest of the NSRR community to promote new ideas and identify opportunities for collaboration in the field of sleep research. This is an exciting opportunity to get to know other NSRR users and the NSRR team, and to discuss the latest updates regarding data and tools in the repository. Please also share this invitation with your colleagues, especially trainees and early investigators.
We invite you to complete the application form so we can identify an initial group of individuals who will provide representation of a range of relevant interests and skills. For those who accept the invitation to attend, the NSRR will cover the cost of economy roundtrip airfare to Boston and one night of hotel accommodation. Note that this will be the first of what we hope will be an annual meeting, so even if you do not attend this meeting, we hope you or your colleagues may be interested in future meetings.
Please click on this link to submit your application: https://tryslice.io/survey/national-sleep-research-resource-early-adopters-meeting-10-09-2015
National Sleep Research Resource (NSRR)
Academic User’s Group Meeting and Conference Call Minutes
Monday, March 1, 2014 12pm - 1pm EST
Via Conference Call:
Response to Feedback from Previous Call: S. Redline gave update on the response to feedback from previous AUG call (01/31).
Response to Feedback w/ S. Warby and P. Peppard: In response to feedback from AUG members, S. Warby and P. Peppard, priorities have been focused to providing thorough data dictionaries to allow mapping within cohorts, rather than across cohorts
Updates to Data Resource: SleepData.org will be released to the public on Tuesday, April 1. All SHHS studies will be made available, once users are granted access. SHHS data is linked to BioLINCC using a common ID. CHAT data will be released and made available ~July 1.
New ABOUT page: About page was created for NSRR members and AUG members to introduce users to our team.
New Tools: The purpose of provided tools is to work tightly with data provided in data set. Tools are designed to do ‘pre-processing’ of dataset for users.
DAUA Process and Updates: DAUA process has been established. All users must submit a DAUA, along with IRB review/approval, in order to obtain access to the data sets. Each data set will require a separate DAUA from each user. The DAUA grants the user approval for 3-years of access to the data set or until the expiration date, as outlined in the user’s IRB approval.
Other enhancements planned: We plan on providing a forum for users to meet other researchers from the community. Strength of forums is driven by users, not by the format of the forum.
January 31, 2014 3:00 p.m. EST
Introduction/Welcome to the AUG Susan R. opened the meeting and provided a brief introduction of NSRR staff members from Brigham and Women’s Hospital, Beth Israel Deaconess Medical Center, and Case Western Reserve University. A brief introduction of the AUG members was then provided.
NSRR Overview Susan R. provided an overview of the NSRR grant main goal, and discussed collaboration with BioLincc and possible future collaboration with dbGaP. Funding for NSRR is via a 5 year NIH/NHLBI grant with support from Brigham and Women’s Hospital (BWH) in years 6 through 10. The NSRR Aims were described (summarized below), and an NSRR Organizational chart was presented with an explanation of the working groups/teams.
Purpose of the AUG Susan R.—Academic User Governing Committee is comprised of key stakeholders who are representatives of major participating study groups, community users, and technical experts. The AUG will meet bi-monthly via conference call and 1 to 2 times annually in person. The AUG will develop governance policies, provide input into usability, accelerate the dissemination of tools, help prioritize tasks, provide feedback on web-based user guides and webinars, and create a dynamic user community.
Unveiling of sleepdata.org Remo M. created a survey requesting feedback from AUG members after the meeting and explained the 3 components of sleepdata.org: Explore datasets, download data, analyze data.
Regulatory Issues Susan R. explained that NSRR is trying to be as congruent as possible with BioLincc and to closely collaborate with that group. BioLincc has agreed to provide a link on their site to sleepdata.org when the BioLincc data repository contains data from research participants who also have PSG data residing in the NSRR. NSRR has agreed to do the same. In the future, NSRR hopes to form a similar relationship with dbGaP. Susan R. also discussed the need for a Data Use Agreement (DUA) and IRB review at sites wishing access to NSRR data. Susan R. will work with cohorts to ensure Steering Committees are comfortable with the data that is being shared.
Questions from the AUG