The summing comparator includes: a first integrator; a second integrator for receiving an output of the first integrator; and a comparator for switching when the output of the first integrator is greater than the output of the second integrator. Thus, it is possible to reflect network status that varies constantly in selecting an optimum route in a routing protocol, thus maximizing optimum route effects and increasing transmission efficiency of a network. A distal portion of a catheter can be advanced to an existing blood vessel to deliver the arteriogenic factor. The method may further include storing the delta image with a reference to the reference image. The measured load and speed can be transmitted to a processor which can perform calculations and comparisons thereon, and can transmit related notifications to client devices through a network.