How to separately sum up disparate number-value clusters with varied gaps between 'em

[SleepnGood]

My request and purpose is to obtain or develop my first macro (of any significance at all) to interpret data produced by my sleep apnea device's EDF files, which are, to me, huge with over 700k data rows. To date I've not found a way to use usual Excel workbook features to do the immediate task for anything but small samples of a few thousand data points. Some mix of "manual" methods with Excel and EDF data files has provided helpful illumination. It's time to do whole files.

New here with little Forum experience, I've blundered but am trying to learn how to handle myself. a long time Excel Worksheet user (for some engineering and financial work, going back to 1986, DOS and Excel 2.0).

The attachment is an Excel Workbook with its 2 sheets (and a macro if successful sending these 3 items). Sheet 1 is intended to be an input sheet for the macro I desire and haven't been successful writing. Sheet 2 was deleted. Sheet 3 has dummy data and a mix of mental and Excel arithmetic work for illustration of my Subject difficulty and the need: the problem is scattered, varying-count clusters of numeric values with varying gaps between them. The range of a SUM function must vary (as far a I know), yet it must be copy-able down 700 ks rows. Any single SUM range working for most all waves will generate hundreds, if not thousands, of sum errors.

Writing the macro has stumped me and that is embarrassing because my sense is that it will be very short and simple. I'm tangled up in mixing types, not handling range objects properly etc. I haven't looked that much here yet, but find that most writers narrowly illustrate single topic instances using generic placeholders without any full context examples that I learn fastest from. Those show coherent concurrent uses of key elements.

The total focus of my request is on adding up .04 second by up to, say, 50 Liter/second strips inside each inhalation "half wave" of each breath--that is, the goal is to do numerical integration to determine the +curve-axis-enclosed wave areas representing air-volume delivered by my device during sleep. Once I have sums of each inhalation wave area I can then move to doing a sliding window smoothing and do comparisons of windowed wave averages to the next single wave. Then compute percentiles, etc.