Improved medical filaments for use with dilators to be inserted into a patient, for example into the vascular lumen, are provided, as well as combinations of filaments and dilators. The claimed embodiment includes forwarding information through the ring according to one or more spanning tree instances, each instance designating one of the group of ring ports as a respective alternate port that is in a state of discarding. It is thus possible to take the reaction times of the individual devices or actuators required for the cascading of emergency-off devices for switching on into consideration for a common switch-on operation. In response to determining that at least one additional virtual machine should be started up, the load balancer sends at least one command to start up the at least one additional virtual machine in at least one of the physical machines. An alternative temperature measuring device installs an optical temperature sensing material within a test substrate behind an optical window, and then views the sensing material through the window.