The NBTdatabase is build as an relational database with nbt_Info.ProjectID, nbt_Info.SubjectID, and nbt_Info.Condition as primary keys.
Meta data exists on four levels:
nbt_Info object stored in ProjectInfo.mat
with this information
Description of Conditions
nbt_Info object stored in each Subject folder in the SubjectInfo.mat or if more convenient in each _info file.
The subject meta information is bound to the project information via the nbt_Info.ProjectID field.
For each signal a corresponding _info file is stored with meta data. This file is bound to the Subject via the nbt_Info.SubjectID field, and condition via the nbt_Info.ProjectID and ConditionID.