Calibrated current divider network for precision current delivery during high-voltage transthoracic defibrillation.
The design of a calibrated resistive-network current divider for precision current delivery during transthoracic defibrillation shocks is presented together with test results. The current divider presents a constant 50-ohm load to the defibrillator and thus maintains a constant pulse shape. Current is selected before the shock by setting three rheostats using a computer-generated calibration table. Following each shock, the data acquisition and display software updates the calibration table based on the measured value of transthoracic resistance. Over a range of 15-27 A, the root-mean-square (rms) error for delivered versus selected current was 0.48% for a 45-ohm resistive load, and 0.71% for a 100-ohm load. These test results were confirmed by animal experiments. Over 3 dogs, the rms error was 0.49% from 15-27 A and not greater than 1.5% over the entire 8-44 A range.
Deale
O Carlton
OC
Cardiology Division, Department of Medicine, Weill Medical College of Cornell University, New York, NY 10021, USA. ocdeale@ieee.org
Ng
Kwong T
KT
Lerman
Bruce B
BB
D002138:Calibration; D047548:Defibrillators; D017097:Electric Impedance; D004582:Electronics, Medical; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D013909:Thorax / Q000503:physiopathology