Babbs C F, Whistler S J
Med Instrum. 1978 Jan-Feb;12(1):34-7.
A method is developed for determing actual values of circuit elements in a damped sine wave (Lown waveform) defibrillator solely from measurements of the output, using two or more power resistors and a storage oscilloscope. If a defibrillator containing capacitance C, inductance L, and internal resistance RI, is discharged into increasing 5- to 100-ohm resistive loads R, it is shown for underdamped output waveforms that â = RI/2L + R/2L and ĉ = CRI + CR, where â = pi[t2tan(pit1/t2)], ĉ = 2â/[â2 + (pi/t2)2], t1 = time from onset to peak, and t2 = time from onset to first zero crossing of the output waveform on the oscilloscope trace. Linear plots of â vs R are constructed for seven defibrillators, and values of RI and L computed as intercept/slope and 1/(2 slope) respectively. C is given by the slope of a linear plot of ĉ vs R. Delivered energy is accurately predicted as stored energy X R/(RI + R).
开发了一种方法，仅通过使用两个或更多功率电阻器和存储示波器对输出进行测量，来确定阻尼正弦波（洛恩波形）除颤器中电路元件的实际值。如果将包含电容C、电感L和内阻RI的除颤器放电到5至100欧姆的递增电阻负载R中，对于欠阻尼输出波形，结果表明â = RI/2L + R/2L且ĉ = CRI + CR，其中â = π[t2tan(πt1/t2)]，ĉ = 2â/[â2 + (π/t2)2]，t1是从起始到峰值的时间，t2是从起始到示波器迹线上输出波形的第一个过零点的时间。为七个除颤器构建了â与R的线性图，RI和L的值分别计算为截距/斜率和1/(2斜率)。C由ĉ与R的线性图的斜率给出。输送能量被准确预测为存储能量×R/(RI + R)。
