A method and apparatus are provided for processing a delayed resource reservation request in an optical telecommunication network for transferring data between a source device and a destination device, wherein the control plane is different from the transfer plane. The present inventors have found that many conventional medical devices contain a metallic component that comes into contact with a pharmaceutically active material during use, and that the contact substantially reduce the pharmaceutical effectiveness of the pharmaceutically active material. A current value of a current of the electric signal is measured.