We cannot answer your question because you only posted your top level VI. All the subVIs are missing. In the future, use File»Save As.. and choose to duplicate the hierarchy to a new location. Pack the new code in a ZIP file and post that. Alternately, you can create a source distribution using the application builder (you are using projects?).
I will assume you need the height, width, and area for each pulse, since that is normally how a pulse plethysmographic signal is used. LabVIEW has standard VIs to measure all of these parameters. Look in the Signal Processing » Waveform Measurements palette for most of them. Use one of the integration VIs to find your area.
If you need further help, please post all your code.
