A data logging system and method in which an implantable medical device transmits logged data to an external data logging device with low energy potential signals. The implantable device generates potential signals modulated with digitally encoded data by operating a current source to cause corresponding electrical potentials that can be sensed at the skin surface by the external data logging device. The data logging device then demodulates the sensed potentials to derive the digital data and stores the data in a data logging storage medium.
This application is a continuation of U.S. patent application Ser. No. 09/740,258, filed on Dec. 18, 2000, now issued as U.S. Pat. No. 6,628,985, and a continuation-in-part of U.S. patent application Ser. No. 09/999,260, filed on Nov. 30, 2001, now issued as U.S. Pat. No. 7,201,733 which is a continuation of U.S. patent application Ser. No. 09/422,433, filed on Oct. 21, 1999, now issued as U.S. Pat. No. 6,361,522, the disclosures of which are hereby incorporated by reference.
