A wound closure apparatus to promote tissue healing at a wound is provided and includes a porous pad positioned at the wound and a suction pump in fluid communication with the porous pad to provide a negative pressure to the porous pad. The suction pump is disposed within a housing. A canister is fluidly connected between the porous pad and the suction pump to collect fluids drawn from the wound by the suction pump, and the canister is removably received by a recess in the housing. A wound cover is positioned over the porous pad to secure the porous pad at the wound, and a switch provides a signal indicating that the canister properly resides within the recess when the switch is pressed.
