ELECTRICAL POWER CONTROLLERS FOR POWER-OPERATED WHEELCHAIRS AND CARTS, AND ASSOCIATED CONTROLS AND CABLES; CONTROLS TO ASSIST THE SEVERELY HANDICAPPED, NAMELY ELECTRICAL AND ELECTRONIC SWITCHES, JOYSTICKS, BREATH ACTUATORS, ATTENDANT SIGNALLING AND ALERTING CONTROLS, AND WIRELESS REMOTE CONTROLS [ ; AND COMMUNICATORS ENABLING A DISABLED PERSON TO CONVEY MESSAGES ]