Embodiments of negative pressure wound therapy systems and methods aredisclosed. In one embodiment, a systemincludes a wound dressing, negative pressure source, switch, and controlcircuitry. The switch can include an actuator that toggles statesof first and second pairs of contacts in response to a user input. The controlcircuitry can supply negative pressure with the negativepressure source when the state of the first pair of contacts is a first stateand the state of the second pair of contacts is a second state,and the control circuitry can disable supply of negative pressure with thenegative pressure source when the state of the first pair ofcontacts is not the first state or the state of the second pair of contacts isnot the second state.
