体表脉冲电刺激大动物的安全性评估

Security assessment of surface pulsed electrical stimulation in big animals

背景:目前电刺激技术已成为研究热点,但其对机体心电活动的影响尚不明确,且既往此方面研究主要针对小型动物。目的:在不影响心电活动的前提下,寻找刺激猪肝区所能使用最大的脉冲电压及频率。方法:取健康雄性荣昌猪3头,将脉冲电刺激仪输出电极固定于猪肝右叶体表投影前后对应部位,设置固定电刺激参数为波宽10 ms、方波,刺激时间为1 h,分别进行5-100 V的电压耐受实验和1-5 Hz的频率耐受实验,观察猪的动态心电图变化、其不适反应和生活行为的改变。结果与结论:电压耐受实验中脉冲电刺激电压高低与心率增量呈正相关;当电压>35 V时,可发生窦性心律不齐、室性早搏等轻度心律失常,无恶性心律失常、死亡;当电压>60 V时,可见电刺激诱发形成的q Rs波。频率耐受实验中当频率>2 Hz时可见心律失常发生,无恶性心律失常,脉冲电刺激可诱发形成qR s波。提示选择参数为电压35 V、频率2 Hz的脉冲电刺激猪肝区是安全的,电压大于35 V或频率大于2 Hz的脉冲电刺激猪肝区均可引发心律失常,多为良性心律失常。

BACKGROUND： At present, electrical stimulation technology has become a hot topic, but its effect on body＇s electrical activity remains unclear. Moreover, previous studies on this aspect mainly focused on small-sized animals. OBJECTIVE： Under the premise without prejudice to cardiac electrical activity, to find the maximum pulse voltage and frequency of electrostimulation that is taken on the liver area of pigs. METHODS： Three healthy male Rong-Chang pigs were obtained. Pulse electrical stimulator electrodes were fixed on right lobe of the surface projection of corresponding liver area. Fixed electrical stimulation parameters were set, including pulse width 10 ms, square wave, stimulation time 1 hour. They received voltage tolerance experiment between 5 V and 100 V and a frequency tolerance experiment between 1 Hz and 5 Hz. A detail record of pigs＇ electrocardiogram, discomfort reaction and changes in life behavior of the pigs were obtained. RESULTS AND CONCLUSION： During voltage tolerance experiment, high- and low-voltage electrical stimulation pulse was positively associated with heart rate increment. When the voltage was greater than 35 V, mild arrhythmia such as sinus arrhythmia and ventricular premature beats appeared, without malignant arrhythmia or death. When the voltage was greater than 60 V, q Rs formation induced by electrical stimulation wave occurred. In frequency tolerance experiment, when frequency was greater than 2 Hz, arrhythmia appeared, no malignant arrhythmia was found. Pulsed electrical stimulation can induce the formation of q Rs wave. Above findings suggest that the appropriate frequency and voltage of pulse electrical stimulation are 2 Hz and 35 V. At 35 V voltage or 2 Hz frequency, pulsed electrical stimulation on the liver area can cause arrhythmia, mostly benign arrhythmia.