Abstract: A patient signalling system comprising a touch sensitive capacitive transducer adapted to be conveniently and comfortably placed with a patient afflicted with an illness or paralysis rendering him incapable of producing any significant manual force or dexterity, a flexible electrical cable of appreciable length connected at one end to the transducer, and a circuit located remote from the patient and connected to the other end of the cable for converting a change in capacitance of the transducer when touched by the patient into an electrical signal for causing operation of an appliance such as a signalling or communication device connected to the circuit. The circuit includes an input stage in the form of a high input impedance semiconductor device, a direct coupled a.c. amplifier, a resistive coupled a.c. amplifier, and a d.c. semiconductor switch. The system can include provision for patient electrical isolation and low battery voltage indication.