An image data computing apparatus for computing three-dimensional image data on the basis of detection data obtained by employing a two-dimensional sensor array including a plurality of ultrasonic sensors. A procedure for reproduction of a calibration position of an aligned and afterwards displaced calibration substrate uses first and second measurement systems to calculate a new offset position of the calibration substrate after a second wafer is loaded on the wafer chuck. Managing a given one of the media parties may include maintaining a queue of media items, allowing users in the media party to provide input to add media items to the queue and to provide input to skip media items in the queue. The processing chamber can be lowered by a vertically moving mechanism. In embodiments, the surface layer further comprises a particulate silica filler in an amount of about 10 volume percent or less, based on total volume of the surface layer. The biodegradable implants may take various forms, such as rods, pellets, beads, strips, or microparticles, and may be delivered into a sinus in various pharmaceutically acceptable carriers.