Abstract: An extra-capillary fluid cycling unit for maintaining and cycling fluid volumes in a cell culture chamber includes a housing and a first flexible reservoir extra-capillary fluid reservoir disposed in the housing. The extra-capillary fluid reservoir is in fluid communication with a cell culture chamber. A second flexible reservoir is also located in the housing, the second flexible reservoir being in fluid communication with a pressure source. A sensor plate is movably disposed in the housing between the extra-capillary reservoir and the second reservoir, wherein the second reservoir is pressurized to move the sensor plate in relation to the extra-capillary reservoir to cause fluid cycling and maintain fluid volumes in the cell growth chamber.

Abstract: A sonic transducer includes a transducer body and a drive element coupled to the transducer body to produce a sonic output in response to an applied electrical input. A sense element is coupled to the sonic drive element and is configured to provide an electrical feedback output related to the sonic output. The electrical feedback output is adapted to be used to control the applied electrical input to the sonic drive element so as to control the energy delivered to the working area or tip of the transducer.