A method for terminating bleeding from a portion of a bone, which portion has been opened so as to be subject to bleeding, including the steps of extending a covering over the opened portion of the bone, and fixing the covering to the bone such that the covering is in snug engagement with the opened portion of the bone so as to terminate bleeding from the bone. The modified enzyme has been modified with a bonding agent that improves bonding. An output wavelength discriminator receives the reflected sum-frequency that is generated. Timing alignment among each of many field units and the base station is achieved by analyzing messages received at the base station in a corresponding time slot from each field unit.