Estimation of Electrical Cell–Capillary Admittance During Injection with Frequency Response Method

This paper describes electrical equivalent circuit models of cell–capillary admittance during injection of a living cell and presents a measurement system to estimate corresponding frequency responses during microinjection tests. Since the admittance estimate is calculated from data collected during injection, the amount of data is limited. To overcome this constraint, the approach proposed in this paper takes advantage of properties of periodic pseudo random binary sequence (PRBS) excitation signal and avoids end effect anomalies of correlation calculation. The fast and accurate estimation is used to detect the degree of contact during cell injection and to detect breakage and clogging of capillary during a sequence of multiple operations.