A space filler material is used to prevent accumulation of debris that could later foul the operation of adjacent moving parts. The bitline biasing circuit operating to provide a negative biasing voltage to the bitline. The first structural unit is derived from a tetraalkoxysilane. Energy is then applied through a distal tip of the shaft in order to induce desiccation and plug formation in a blood pool formed between the distal end of the shaft and the wall of the blood vessel. The subassembly is intended to be implemented as a modular unit assembled outside of the hydraulic housing, wherein the guide bushing and the valve element are fastened to one another, and the piston is secured in a captive manner in the guide bushing. The sensor is coupled to the bearing assembly.