An internal-combustion engine receives no air from outside atmosphere and it discharges no gas into outside atmosphere. The side sheaths may be collapsed as the introducer is positioned in a desired location of a patient to maintain a low profile. A cut 64 into the extrudate 10 is performed using an ultrasonic knife 27 that vibrates at one or more frequencies. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. Security measures inhibit video game piracy. The elastic sealing member is pierceable to provide a passage for injection of the heat transfer fluid through the elastic sealing member, and is contractible to seal the passage.