A method system and program for encoding and decoding a speech signal including error correction data. The shim piece is used to form a shim of a magnet and is designed to suppress eddy currents in the shim created by the introduction of a gradient magnetic field. Internal bumpers within the inner chamber act to limit the range of motion or travel of at least one mobile element within the inner chamber. A tube is in fluid communication with the injector manifold and extends into a chamber having fluid communication with the fluid source, the chemical and fluid from the fluid source combining in the chamber and discharged therefrom.