A method of applying electrotherapy to the heart of a patient includes positioning electrodes in communication with the heart of the patient; monitoring the patient’s heart to determine if its fibrillating; and providing a first signal with a current generator to the heart through the electrodes in response to an indication that the heart is fibrillating. The plurality of coverage models are then arranged in a hierarchy of increasing coverage level and the program is tested using at least a subset of the coverage models in a sequence according to the hierarchy so as to achieve a predetermined overall level of coverage. The at least one printed circuit board is at least partially decoupled relative to the at least one housing component of the electronic module housing. In one embodiment, the vehicle includes steering means for pivoting the front wheel about a first vertical axis to control the direction of movement of the vehicle, and a hub and pivot means mounting the hub on the outer end of the swing arm for pivotal movement of the rear wheel about a second vertical axis. Because a jammed staple protrudes from the release holes, the jammed staple can be pulled out from the release holes using the fingers. The robot includes a first mechanism of moving the robot at least along the width direction, a second mechanism of pulling out or loading the cell units from or into the rack, and a third mechanism of unloading or loading the cartridge from or into one of the cells while the cell unit is pulled out, and loading or unloading the cartridge into or from a drive operating the cartridge.