How do I synchronize signals???

[Marat]

I have a patient breathing and I am constantly sampling gases and pressure from the mouth. I have a signal from gas analyzer (Signal A) telling me concentrations of expired gas and from pressure transducer telling me what part of the breath cycle I am in (Signal B). Signal A is slower than signal B. I want to align them, so that I know exactly what concentraion of gas occurs during which part of the breath. I want to record raw ALIGNED signals (both A and B), but also be able to pick the concentration of expired gas just prior to the start of inspiration and record them on breath-by-breath basis.

Thanks,

Marat

[Brett_B.]

Marat,

I don't know anything about your setup...but the easiest thing to do would be a continuous acquisition for both signals A&B. You would have a constant stream of parallel data that you could analyze later. It is always better to have more data than wanted as opposed to less data than needed.

A more complicated approach, and again I don't know what HW or SW you are using, would be an analog trigger off of your pressure transducer. You could set the trigger window based on the part of the breath cycle. This would enable you to segment your data based on location in breath cycle. Again...in this case it sounds like it would be easier to take in all the data and delete that which you don't want.

-Brett