A document retrieval system having improved response time. The clipboard manager allows a user to select data from a second document. Expandable as well as fixed-dimension non-expandable pulmonary vein prosthetic valves for implantation by a variety of surgical and percutaneous procedures are also described. The method takes linear time as a function of the number of pins in the net and is much faster than using a Steiner tree method in this context. An output module can receive the linearized signal from the linearization module and provide a device output signal. The time of the receiving device at each communication channel comprises a phase lock time and a reception time of a whole signal section.