A method and apparatus for providing security to factory automation devices in a switched Ethernet network. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of the patient’s heart, and create a three-dimensional model representing at least a portion of the patient’s heart based on the patient-specific data. The walls of the vessel prevent the loss of wax from run off when the wax is melted by the flaming wick when lit. Each voice customer is allotted one or more frames or portions of frames within the superframe, called sub-frames, as is needed to deliver the lower data rate, low latency voice communication. The controller is coupled to the converter and that receives the digital signal. Said antimicrobial sand filter consists of organic quaternary ammonium salt and inorganic metal compound.