US Patent 9713568 Mechanical CPR device with automatic suction cup attachment

A suction cup on the end of a piston of a mechanical CPR device can be automatically attached to a patient's torso. The mechanical CPR device can extend the piston until a first position at which the suction cup comes into contact with the patient's torso. The piston can be further extended to cause air to be forced out from an area between the suction cup and the patient's torso until a first threshold is reached. The piston can be retracted until the suction cup is at the first position. The piston can be further retracted from the first position until a second threshold is exceeded. The piston can then be extended to a second point at which the second threshold is no longer exceeded.