Process monitoring and particle characterization with ultrasonic backscattering

摘要

A fermention process is monitored by detecting ultrasound backscattered from the cells as a function of time. A transducer 46 is placed in a fermentor 30 and transmits ultrasound towards a reflecting surface 50 . The transducer receives that portion of the ultrasound which reflects from the reflecting surface 50 , as well as that portion of the ultrasound which backscatters from cells 34 between the transducer 46 and the reflecting surface 50 . Signals from the transducer are conditioned and subsequently processed to provide output to a controller regarding the status of the fermentation process in real time. The backscattering measurements can be used to determine a growth phase transition, such as the transition between the logarithmic growth phase of the cells and their stationary phase.