Database Creation for 1-d CNN implementation

Hello there, I'm implementing CNN for signal classification problem, for which I need to create the database of the signals which I'll be giving as input to the CNN. To create the database there is a function called imageDatastore and some other database functions, which will create the database of images only. If signals which are stored in .mat( an array of 1xn) format and are given to this function, it will create the database, but will give problem at the time of trainNetwork , error as unable to read the file. Please suggest me some technique to create the database of my signals. What changes should I make in the existing functions so as to get the database of signals ?

     dbs = imageDatastore(fullfile(rootFolder, categories),'IncludeSubfolders', true, 'FileExtensions',{'.mat'}, 'LabelSource', 'foldernames')

this is code I'm using to create the database, but its not useful at time of training the network.