Jesus’ power in this context is the divine energy behind his miraculous acts. It seems probable that Jesus felt this divine energy leave him as a bodily sensation, though we cannot be sure. What matters is his knowledge that of all the people touching him, only the woman did so with the purpose of being healed. This touch registered to Jesus as a touch of faith in him.1
30 And Jesus, perceiving in himself that power had gone out from him, immediately turned about in the crowd and said, “Who touched my garments?”