Hello,
I acquired fNIRS data using the Artinis Brite system, which records at 762 nm and 841 nm. When I attempt to compute the fluences on the warped MRI (Colin27) to the head digitization points, I encounter the following error:
Liner23: nst_get_tissues_optical_properties (line 23). No optical property for wavelength 762 nm for tissue Background.
It seems that there are no predefined optical properties for 762 nm in the current setup. Has anyone encountered a similar issue? Is there a way to manually specify the optical properties for this wavelength or adjust the pipeline to accommodate it?
Thanks,
Maxime
Hello,
When computing the fluences, we need to know the optical property of the tissues for the specific walevelengh used by the system. Think about those as the tissues conductivity when you compute the forward model in EEG/MEG. (See table 2 here: Optica Publishing Group)
In Nirstorm, we define those coeficient here: nirstorm/bst_plugin/forward/tissues_property.json at master · Nirstorm/nirstorm · GitHub . (ie. FOr each tissue, we define mua, mus, g and n).
In you case, you wavelengh are quite close to the one provided ( 690, and 830). SO you might be able to replace all 690 and 80 respectively by 762 and 841 to use the property of 690 and 830.
But i agree that we should find value in the literature for more wavelengh and a system, similar as to how we enter the conductivity, to allow user to specify the tissue property when we dont have value for it 