Fola, If you look at the data, the artifact always occurs at the same value (in the y-axis). I suspect that it is an artifact from the auto-ranging function. You are having the issue at ~1.6uS, or 625k. There is a autorange switch at 680k (1470uS), which I think is very suspicious. You could try collecting data without auto-ranging and compare the results -- for example, if you select range2, accuracy will suffer <1470 but you should have the results you want for peaks of GSR activity.
Alternatively you could try skin preparation to shift the GSR curve upwards away from the range transition or changing the time constants in the code for auto-ranging. I would also point you to the GSR User Guide Rev 1.0 on the Shimmer website-- what sample rate are you using? Can you provide a sample-level zoom in to one of the saturation periods? -Ben On Wed, Sep 5, 2012 at 5:21 PM, Fola Alamudun <[email protected]> wrote: > I am including images of what the data looks like over a period of about 6 > hours of data collection. > Does anyone have any advice on how to fix this issue? I have read that this > may have to do with pressure on the gsr node which may cause flat-lining as > we are seeing in our data. > > > "Nothing will benefit human health and increase chances for survival of life > on Earth as much as the evolution to a vegetarian diet." ~ Albert Einstein > (1879 - 1955). > > Fola Alamudun > Computer Engineering > Texas A&M University > mobile: 469-995-4088 | email: [email protected] > > > On Tue, Sep 4, 2012 at 7:32 PM, Fola Alamudun <[email protected]> > wrote: >> >> Hello all, >> >> I am having some issues with the shimmer gsr unit. When we configure this >> unit to collect data using the auto range function, we notice that the >> resistance values saturate about half way / three quarter way through data >> collection. >> I noticed someone else had experienced this but saw no response to the >> question and so i am reposting with the hopes to find a solution to this >> soonest. >> We are using shimmer gsr and it has an orange padding between the gsr unit >> node and the main board (this, i read, was supposed to reduce the >> possibility of the sensor saturating due to pressure). >> Thanks in advance for any help i receive. >> >> >> "Nothing will benefit human health and increase chances for survival of >> life on Earth as much as the evolution to a vegetarian diet." ~ Albert >> Einstein (1879 - 1955). >> >> Fola Alamudun >> Computer Engineering >> Texas A&M University >> mobile: 469-995-4088 | email: [email protected] > > > > _______________________________________________ > Shimmer-users mailing list > [email protected] > https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users > _______________________________________________ Shimmer-users mailing list [email protected] https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users
