1. A method for creating a patient-specific template from at least one record of electrographic signal data stored by an implantable device, the method comprising the steps of: uploading the at least one record of electrographic signal data from the implantable device to an external apparatus; processing the at least one record to generate at least one parameter; and forming the patient-specific template from the at least one parameter by performing a single local minimum variant of a greedy line search.