Just wanted to report on my results, for whomever may be interested.
I applied a simple "decision" to the 16 period moving average:
IF moving average > 0 I am blowing on the sensor
IF moving average < 0 I am NOT blowing on the sensor
with the corollary that:
IF moving average == 0 I am doing whatever I was doing before // No need to actually state
This is the result in graphic form:
The blue line is the sensor data, the red line is the moving average (multiplied by 100 for ease of plotting) and the green line is the result of the decision: 100 I am blowing, 0 I am not blowing.
It's getting accurate, though there are some false positives and false negatives now and then and, in this very example, there are 86 ms of delay from the beginning of the decay (when I stop blowing) to the response of the moving average (when the software realized that I stopped blowing).
I'll continue tweaking the software.
If there is interest I'll keep posting updates.