In a DC to DC converter, first and second primary windings are magnetically coupled to a first secondary winding. The cushion includes a pad that may be formed of a resilient foam material. The blade nozzle emits at least one jet of heating andor oxygen-cutting fluids through its leading edge to strike the heating edge of the slot where it combines with the jet of oxygen-cutting fluids emitted by the oxygen-cutting torch to form a leading edge of the slot having a profile in the form of a broken line. The display panel displays different images when the light deflectors are in the different operable states. Other embodiments are disclosed. The sphincterotome includes an actuatable handle attached to an elongate shaft having a needle knife near its distal end.