Defibrillator patient connection system with automatic identification

A defibrillator patient connection system is disclosed for automatically identifying to a defibrillator system the type of pads or paddles assembly connected to the system for conveying electrical energy to shock a patient. Each of the available pads or paddles assemblies is identified by a corresponding analog voltage level provided to the base unit through a corresponding cable assembly. The identification voltage is sensed by an A/D converter in the defibrillator base unit. The identification voltage is provided to the base unit on a charge-done signal line which otherwise is asserted by the base unit to controllably actuate a charge-done indicator light in an external paddles assembly. The disclosed methods and apparatus thus maintain a simple defibrillator/cable assembly interface and require no additional signal lines for implementing automatic identification. A plug assembly latch mechanism also is disclosed that provides the dual functions of locking a plug assembly in place in the defibrillator base unit and preventing actuation of discharge buttons on the plug assembly when the latch is not in the locked position, thereby avoiding a high energy discharge unless the plug assembly is securely locked in position.