Abstract: A modular vehicle comprises a preassembled undercarriage module, a preassembled overcarriage module, and coupling means for releasably coupling the overcarriage module to the undercarriage module. The undercarriage module includes wheels for permitting travel of the vehicle on a travelling surface, means for holding a power source for supplying operating power to the vehicle, and means for directing controlled motive power from the power source to at least one of the wheels. The overcarriage module includes control means linkable with the undercarriage module for controlling operation of the vehicle.

Abstract: A method of sensing and analyzing electrical activity of the human heart comprises the sensing of voltage signals generated by the heart between four electrodes located at key positions on the surface of a subject's body. Signal processing means combines and scales the voltage signals to produce xyz vectorcardiographic signals, electrocardiographic signals corresponding to the lead signals of a 12-lead electrocardiograph, or both.