open-discussion
open-discussion > RE: Shared NIRS Data Format - SNIRF
Nov 16, 2012 08:11 PM | David Boas
RE: Shared NIRS Data Format - SNIRF
Alex,
Thanks for your comments.
1) Time is more general and more informative than storing the data by sample number. When analyzing the data, we need to know the time of each sample. By providing the time variable, it provides this information and allows for variable timing in the acquisition within a channel and between channels.
2) Your point about referencing optodes to 10-20 coordinates is a good one. This is a topic that needs further consideration. There are several approaches already for handling this that are separate from NIRS time series acquisition. I hope that people more experienced on this topic can share there thoughts.
3) source power would be stored in meta data.
4) Please share your thoughts on meta data using this forum. Thanks
Originally posted by Alex Cristia:
Thanks for your comments.
1) Time is more general and more informative than storing the data by sample number. When analyzing the data, we need to know the time of each sample. By providing the time variable, it provides this information and allows for variable timing in the acquisition within a channel and between channels.
2) Your point about referencing optodes to 10-20 coordinates is a good one. This is a topic that needs further consideration. There are several approaches already for handling this that are separate from NIRS time series acquisition. I hope that people more experienced on this topic can share there thoughts.
3) source power would be stored in meta data.
4) Please share your thoughts on meta data using this forum. Thanks
Originally posted by Alex Cristia:
Hello,
Thanks for getting this discussion started, it will be great to have a standard format. I've a couple clarification questions and comments:
- "The time variable. This provides the acquisition time of the measurement relative to the time origin." I'm guessing this is preferable over sample number because (1) there's no need to look at sampling frequency before comparing to studies; (2) some systems may actually store time, if the sampling frequency is variable/there are errors. Is that so?
- You could add a field SD.Origin which can specify the 10-20 electrode used as reference, since most fNIRS neurocog users will have one. This simple addition would make it much easier to incorporate localization in an eventual meta-analysis.
- Would original source power (e.g., 0.6mW) be stored in metadata? Some systems, particularly those which use multiple distances, can specify different powers for each source.
- It would be useful to have a forum with suggested fields for metadata. I won't put them here, but there are several variables that appear to affect data quality in infant research, so it would be useful if we could keep track of them. If you're interested in starting to collect suggestions, let me know and I'll email you my list.
Alex Cristia
--
__________________________
Scientific staff member MPI-Nijmegen
sites.google.com/site/acrsta
Wundtlaan 1
6525 XD, Nijmegen
Netherlands
__________________________
Thanks for getting this discussion started, it will be great to have a standard format. I've a couple clarification questions and comments:
- "The time variable. This provides the acquisition time of the measurement relative to the time origin." I'm guessing this is preferable over sample number because (1) there's no need to look at sampling frequency before comparing to studies; (2) some systems may actually store time, if the sampling frequency is variable/there are errors. Is that so?
- You could add a field SD.Origin which can specify the 10-20 electrode used as reference, since most fNIRS neurocog users will have one. This simple addition would make it much easier to incorporate localization in an eventual meta-analysis.
- Would original source power (e.g., 0.6mW) be stored in metadata? Some systems, particularly those which use multiple distances, can specify different powers for each source.
- It would be useful to have a forum with suggested fields for metadata. I won't put them here, but there are several variables that appear to affect data quality in infant research, so it would be useful if we could keep track of them. If you're interested in starting to collect suggestions, let me know and I'll email you my list.
Alex Cristia
--
__________________________
Scientific staff member MPI-Nijmegen
sites.google.com/site/acrsta
Wundtlaan 1
6525 XD, Nijmegen
Netherlands
__________________________
Threaded View
| Title | Author | Date |
|---|---|---|
| David Boas | Oct 19, 2012 | |
| David Boas | Aug 1, 2013 | |
| Mathieu Coursolle | Apr 2, 2013 | |
| Mathieu Coursolle | Apr 15, 2013 | |
| David Boas | Jul 31, 2013 | |
| David Boas | Jul 31, 2013 | |
| David Boas | Nov 20, 2012 | |
| Alex Cristia | Nov 20, 2012 | |
| Alex Cristia | Nov 5, 2012 | |
| David Boas | Nov 16, 2012 | |
| Mathieu Coursolle | Nov 16, 2012 | |
| Alessandro Torricelli | Oct 25, 2012 | |
| Blaise Frederick | Oct 26, 2012 | |
| David Boas | Nov 5, 2012 | |
| Alessandro Torricelli | Oct 25, 2012 | |
| Mathieu Coursolle | Oct 22, 2012 | |
| Blaise Frederick | Oct 22, 2012 | |
| David Boas | Nov 5, 2012 | |
| Mathieu Coursolle | Nov 20, 2012 | |