De Bock Filip, De Wachter Stefan, Wyndaele Jean-Jacques
Department of Urology, University of Antwerp, Wilrijk, Belgium.
Neurourol Urodyn. 2009;28(3):246-50. doi: 10.1002/nau.20633.
Intravesical electrical stimulation (IVES) with square wave pulses, low frequencies and short pulse durations has been used for decades in diagnosis and treatment of lower urinary tract dysfunction. The results are not always satisfying. Several parameters have been studied before but not the use of other waveforms and the effect of electrical charge. This study compares the effect of changing waveforms, frequencies, pulse durations, amplitudes and derived parameters in IVES.
IVES, performed in seven female Sprague-Dawley rats, was given for 10 sec with constant current unipolar square or sawtooth pulses with different pulse durations (10, 20, or 100 msec), frequencies (5, 20, or 10 Hz) and amplitudes (2, 4, 6, and 8mA). Bladder pressure was recorded. Electrical charge and power were calculated.
Stimulation with the same frequency, same pulse duration and same amplitude showed significantly higher maximal pressure rises (max DeltaP) for square wave (all P < 0.05). Stimulation with the same frequency, same pulse duration and same electrical charge, gave no different max DeltaP for both waveforms (all P > 0.05). The charge and power could be reduced without changing max DeltaP, by lowering frequencies and/or shortening pulse durations.
Sawtooth pulses are equally effective as square pulses for inducing detrusor contraction during IVES with the same electric charge. Frequency and pulse duration had, in this study, a minor influence on the efficacy of IVES. Lower frequency and/or shorter pulse duration results in lower charge and power without changing stimulation efficacy. This finding can be important for the battery life of implanted stimulators and for patient's comfort.
数十年来，具有方波脉冲、低频和短脉冲持续时间的膀胱内电刺激（IVES）一直用于下尿路功能障碍的诊断和治疗。但其结果并非总是尽如人意。此前已经对多个参数进行了研究，但未涉及其他波形的使用以及电荷的影响。本研究比较了在IVES中改变波形、频率、脉冲持续时间、幅度及派生参数的效果。
对7只雌性斯普拉格-道利大鼠进行IVES，给予持续10秒的恒定电流单极方波或锯齿波脉冲，其具有不同的脉冲持续时间（10、20或100毫秒）、频率（5、20或10赫兹）和幅度（2、4、6和8毫安）。记录膀胱压力。计算电荷和功率。
在相同频率、相同脉冲持续时间和相同幅度下进行刺激时，方波的最大压力上升值（最大ΔP）显著更高（所有P<0.05）。在相同频率、相同脉冲持续时间和相同电荷下进行刺激时，两种波形的最大ΔP没有差异（所有P>0.05）。通过降低频率和/或缩短脉冲持续时间，可以在不改变最大ΔP的情况下减少电荷和功率。
在相同电荷的IVES期间，锯齿波脉冲在诱导逼尿肌收缩方面与方波脉冲同样有效。在本研究中，频率和脉冲持续时间对IVES的疗效影响较小。较低的频率和/或较短的脉冲持续时间可在不改变刺激效果的情况下降低电荷和功率。这一发现对于植入式刺激器的电池寿命和患者舒适度可能具有重要意义。
