Provided are a method and apparatus for performing medical catheterizationusing electricalpower circuitry disposed outside a medical catheter and remote internalcircuitry disposedwithin the medical catheter. At least one of the power circuitry and theinternal circuitryis isolated from electrical ground. Exactly two wires connect the powercircuitry to the internalcircuitry and a signal generator is provided for generating an alternatingcarrier that iscommunicated from the power circuitry to the internal circuitry via the wires.Decoders aredisposed in the power circuitry and the internal circuitry, and a transceiverperforms half-duplexdata communication between the power circuitry and the internal circuitry byalternatelymodulating the carrier voltage amplitude in one of the power circuitry and theinternalcircuitry and decoding the modulated carrier voltage amplitude in another ofthe power circuitryand the internal circuitry.
