The text does not actually say that Jesus ‘lost power’. when he healed. What it says is that Jesus was aware when power had been used for this reason.
Luke 8:46 (NET) But Jesus said, “Someone touched me, for I know that power has gone out from me.”
We don’t know the details of what this means, but it is clear enough that Jesus was consciously aware of God’s power being used to heal when he touched someone, or when they touched him.