Defibrillation is accomplished by the passage of sufficient current through the heart to terminate ventricular fibrillation (VF). Although current-based defibrillation has been shown to be superior to energy-based defibrillation with monophasic waveforms, defibrillators with biphasic waveforms still use energy as a therapeutic dosage. In the present study, we propose a novel framework of current-based, biphasic defibrillation grounded in transthoracic impedance (TTI) measurements: adjusting the charging voltage to deliver the desired current based on the energy setting and measured pre-shock TTI; and adjusting the pulse duration to deliver the desired energy based on the output current and intra-shock TTI. The defibrillation efficacy of current-based defibrillation was compared with that of energy-based defibrillation in a simulated high impedance rabbit model of VF. Cardiac arrest was induced by pacing the right ventricle for 60 s in 24 New Zealand rabbits (10 males). A defibrillatory shock was applied with one of the two defibrillators after 90 s of VF. The defibrillation thresholds (DFTs) at different pathway impedances were determined utilizing a 5-step up-and-down protocol. The procedure was repeated after an interval of 5 min. A total of 30 fibrillation events and defibrillation attempts were investigated for each animal. The pulse duration was significantly shorter, and the waveform tilt was much lower for the current-based defibrillator. Compared with energy-based defibrillation, the energy, peak voltage, and peak current DFT were markedly lower when the pathway impedance was > 120 Ω, but there were no differences in DFT values when the pathway impedance was between 80 and 120 Ω for current-based defibrillation. Additionally, peak voltage and the peak current DFT were significantly lower for current-based defibrillation when the pathway impedance was < 80 Ω. In sum, a framework of adjusting the charging voltage and shock duration to deliver constant energy for low impedance and constant current for high impedance via pre-shock and intra-shock impedance measurements, greatly improved the defibrillation efficacy of high impedance by lowering the energy DFT.

除颤是通过足够的电流通过心脏以终止心室颤动 (VF) 来完成的。尽管基于电流的除颤已被证明优于具有单相波形的基于能量的除颤，但具有双相波形的除颤器仍然使用能量作为治疗剂量。在本研究中，我们提出了一种基于经胸阻抗 (TTI) 测量的基于电流的双相除颤的新框架：根据能量设置和测量的电击前 TTI 调整充电电压以提供所需的电流；并根据输出电流和内部冲击 TTI 调整脉冲持续时间以提供所需的能量。在模拟的 VF 高阻抗兔模型中，将电流除颤的除颤效果与能量除颤的除颤效果进行了比较。通过在 24 只新西兰兔（10 只雄性）中右心室起搏 60 秒来诱导心脏骤停。在室颤 90 秒后，用两个除颤器中的一个施加除颤电击。不同通路阻抗下的除颤阈值 (DFT) 使用 5 步上下协议确定。间隔 5 分钟后重复该过程。对每只动物总共研究了 30 次颤动事件和除颤尝试。基于电流的除颤器的脉冲持续时间明显更短，波形倾斜要低得多。与基于能量的除颤相比，能量、峰值电压、当通路阻抗 > 120 Ω 时，DFT 和峰值电流 DFT 显着降低，但当通路阻抗在 80 和 120 Ω 之间时，基于电流的除颤的 DFT 值没有差异。此外，当通路阻抗 < 80 Ω 时，基于电流的除颤的峰值电压和峰值电流 DFT 显着降低。综上所述，通过电击前和电击内阻抗测量调整充电电压和电击持续时间为低阻抗提供恒定能量和为高阻抗提供恒定电流的框架，通过降低能量DFT大大提高了高阻抗除颤效率. 当通路阻抗 < 80 Ω 时，基于电流的除颤的峰值电压和峰值电流 DFT 显着降低。综上所述，通过电击前和电击内阻抗测量调整充电电压和电击持续时间为低阻抗提供恒定能量和为高阻抗提供恒定电流的框架，通过降低能量DFT大大提高了高阻抗除颤效率. 当通路阻抗 < 80 Ω 时，基于电流的除颤的峰值电压和峰值电流 DFT 显着降低。综上所述，通过电击前和电击内阻抗测量调整充电电压和电击持续时间为低阻抗提供恒定能量和为高阻抗提供恒定电流的框架，通过降低能量DFT大大提高了高阻抗除颤效率.