高电压输入双管反激辅助电源驱动研究

高性能的开关管驱动技术是实现辅助电源安全、可靠运行的必要条件。首先,针对高电压输入双管反激辅助电源驱动具有高电压隔离、高频率、低延时和无外接电源等特点,对比各种可行的驱动方案,确定了一种安全、简单的变压器隔离双管驱动电路,并设计了相应的驱动器;其次,通过调整驱动变压器绕组比,实现了开关管在各种控制脉冲下的充分导通,通过增加驱动器输出信号耦合电感,提高了驱动信号的同步性;第三,根据驱动脉冲上升、平顶、下降三个阶段,建立了驱动器等效电路模型,推导了相关公式,分析了驱动器主要参数对驱动性能的影响;最后,在300V～2 500V输入的双管反激辅助电源样机上进行了相关实验,验证了所设计的双管隔离驱动器的正确性、可行性。     

高压电位治疗失眠、慢性疲劳的疗效分析

目的:探讨高压电位治疗失眠、慢性疲劳的疗效和安全性。方法:应用高压电位治疗仪治疗30例失眠患者(失眠组)和30例慢性疲劳患者(慢性疲劳组),治疗电压为9000 V,30 min/次,每天1次,5次为1个疗程,共4个疗程;治疗结束后随访2个月,比较治疗前后各指标变化。结果:治疗4个疗程后,失眠组和慢性疲劳组患者的症状/体征指标平均积分显著下降(P0.001),总有效率分别为89.28%、93.11%。两组患者治疗过程中均无不良反应的发生,患者血尿常规、血清丙氨酸氨基转移氨酶(ALT)、血清天门冬氨酸氨基转氨酶(AST)、血肌酐、血尿素氮及心电图无明显改变。结论:高压电位治疗失眠、慢性疲劳临床疗效显著,安全性高。     

Transmembrane Potentials During High Voltage Shocks in Ischemic Cardiac Tissue

Transmembrane, voltage sensitive fluorescent dye (TMF) recording techniques have shown that high voltage shocks (HVS), typically used in defibrillation, produce either hyper- or depolarization of the transmembrane potential (TMP) when delivered in the refractory period of an action potential (AP) in normal cardiac tissue (NT). Further, HVS produce an extension of the AP, which has been hypothesized as a potential mechanism for electrical defibrillation. We examined whether HVS modify TMP of ischemic tissue (IT) in a similar manner. In seven Langendorff rabbit hearts, recordings of APs were obtained in both NT and IT with TMF using di-4-ANEPPS, and diacetylmonoxime (23 μM) to avoid motion artifacts. Local ischemia was produced by occlusion of the LAD. HVS of either biphasic (5 + 5 ms) or (3 + 2 ms) or monophasic shapes (5 ms) were delivered at varying times (20%–90%) of the paced AP. Intracardiac ECG and TMF recordings of the TMP were each amplified, recorded, and digitized at a frequency of 1 kHz. The paced AP in IT was triangular in shape with no obvious phase 3 plateau, typically seen in NT. There was normally a reduced AP amplitude (expressed as fractional fluorescence) in IT (2.6%± 1.79%) compared to 3.8%± 0.66% in NT, and shortened AP duration (137 ± 42 vs 171 ± 11 ms). One hundred-Volt HVS delivered during the refractory period of paced AP in IT in five rabbits, elicited a depolarization response of the TMP with an amplitude up to three times greater than the paced AP. This is in contrast to NT where the 100-V HVS produced hyperpolarization in four hearts, and only a slight depolarization response in one heart. These results suggest that HVS, typically delivered by a defibrillation shock, modify TMPs in a significantly different manner for ischemic cells, which may influence success in defibrillation.     

腰椎间盘MRIT2高信号区在射频治疗椎间盘源性下背痛中的应用

目的：探讨腰椎间盘MRI高信号区与椎间盘源性下背痛的相关性。方法：下背痛患者47例．根据腰椎间盘MRIT2信号强弱进行腰椎间盘退变程度评估分级，对具有MRIT2高信号区的椎间盘进行造影及射频热凝治疗，并分别于治疗前24h内，治疗后7、15及90d时采用VAs疼痛评分法进行疗效评定。结果：具有MRIT2高信号区的椎间盘造影显示所有纤维环均为2-3级破裂，且高信号区均出现在退变椎间盘内，高信号区与纤维环破裂程度及椎间盘退变程度呈正相关（r=0．7859、0．8135，P=0．025、0．01）；射频治疗后VAS评分较治疗前有显著降低（P〈0．05），治疗后90d随访时疗效评定优良率85％，有效率95．7％，与治疗前比较有显著改善（P〈0．01）。结论：具有MRI高信号区的椎间盘是引起椎间盘源性下背痛的责任椎间盘，对其进行射频治疗，可取得良好效果。