A removable and replaceable dispensing head for a fluid dispenser system adapted to deliver the fluid to a user includes a hollow shank extending on an axis. The produced quantitative phase image may have sufficient contrast for label-free auto-segmentation of cell bodies and nuclei. Metal polishes that have been used to clean and regenerate plate surfaces have also provided a sample plate that has optimal performance for reproducible deposition and analysis by MALDI-MS and MALDI-MSMS processes of analyte mixtures. The surgical instrument can also include various mechanisms for adjusting the position of the guide projection relative to the bone anchor. The shape of the bluff body supports a predetermined oscillatory clockwise and counter clockwise movement about a pivot absent the influence of electrical or mechanical devices for biasing the bluff body’s motion for a given velocity, or range of velocities, of the fluid flow. The dryer directs heated air into the drying chamber through the opening to dry the printed web.