How to track open positions which does not fit with the price streaming?

Let’s suppose I’ve traded long at 15:22 on EUR/USD, and I’d like to track some indicators which works very well in two hours range. My broker (OANDA) provide me a good price streaming for all granularities so next two hours bars will be filled at 16:00, 18:00, 20:00 and so on.

The problem is that among 15:22 (when I’ve opened my position) and next bar there are only 38 min, not two hours. Thus, my indicators won’t be as accurate as I would like to. If I try to use shorter time-ranges my strategy just won’t work that good (I’ve backtested it) because there will be more noise.

How do you handle this kind of situations?