How do I continously integrate an air-flow signal?

[lookingforflow]

Hello,

I am trying to integrate an air-flow signal (see attachment) so I can get the volume per breath (sensor is attached to a ventilator). Unfortunately, the signal doesn't look as I expected it. I cut off the negative parts (exhalation) of the signal. I used nearly every integral-VI with lots of different results. In the lower part of the screenshot you can see the integrated signal after I cut off the negative flow. But the result has those weird zig-zags and I expected a nice round curve. Maybe you can help me and tell me what i am doing wrong.

[TMC-NI]

Hi lookingforflow,

I've been scratching my head over this issue for a few days now.  I think this may be a bug.  I recreated the VI, but literally erased and the recreated the graph hooked to the output of the integral, and the integral seems like it works fine now.  Can you try this on your end?