Precision control of eluted activity from a Sr/Rb generator for cardiac positron emission tomography

R. Klein, A. Adler, R.S. Beanlands, R.A. deKemp
The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society  
A rubidium-82 ( 82 Rb) elution system is described for use with clinical positron emission tomography. The system is self-calibrating with 1.4% repeatability, independent of generator activity and elution flow rate. Saline flow is switched between a 82 Sr/ 82 Rb generator and a bypass line to achieve a constant activity elution of 82 Rb. In the present study, pulse width modulation (PWM) of a solenoid valve is compared to simple threshold control as a means to simulate a proportional valve. A
more » ... edictive-corrective control algorithm is developed which produces a constant activity elution within the constraints of long feedback delay and short elution time. Accurate constant-activity elutions of 10-70% of the total generator activity were demonstrated using the threshold comparison control. The adaptive-corrective control of the PWM valve provided a substantial improvement in precision of the steady-state output.
doi:10.1109/iembs.2004.1403433 pmid:17271953 fatcat:mswqcfk3kzedfgptl2ugm7wopi