to vary the inductance and the resonant frequency of the l c circuit as already described an acrylic plastic shield sleeve 79 may be fitted over and secured to the bellows end of sleeve 73 to extend over the side surfaces of the bellows to prevent tissue interference with the bellows holes not shown may be formed in the sidewall of the shield sleeve to insure free fluid circulation around the bellows the distal end of the shield sleeve is open and the inner wall of the shield sleeve is radially spaced from the bellows sidewall to insure free movement of the bellows responsive to pressure changes the l c circuit components with bellows 77 and sleeve 73 and optionally sleeve 79 depending on the application form transducer subassembly 68 which can be mounted in several ways depending upon the geometry of the space in which fluid pressure is to be measured in an epidural configuration 81 as shown in fig7 the transducer subassembly is seated in a hollow dome shaped housing 83 which includes a base 84 and a cover 85 base 84 is a flat circular plate of an implantable material such as acrylic plastic and an opening 86 is formed in the center of the plate a tubular extension 87 is integrally formed with the plate around opening 86 and the extension defines an inwardly extending annular flange 88 against.