Effect of low-frequency pulse percutaneous electric stimulation on peripheral nerve injuries at different sites

BACKGROUND： The postoperative recovery of nerve function in patients with peripheral nerve injury is always an important problem to solve after treatment. The electric stimulation induced electromagnetic field can nourish nerve, postpone muscular atrophy, and help the postoperative neuromuscular function. OBJECTIVE： To observe the effects of low-frequency pulse percutaneous electric stimulation on the functional recovery of postoperative patients with peripheral nerve injury, and quantitatively evaluate the results of electromyogram （EMG） examination before and after treatment. DESIGN ： A retrospective case analysis SETTING： The Sixth People＇s Hospital affiliated to Shanghai Jiaotong University PARTICIPANTS： Nineteen postoperative inpatients with peripheral nerve injury were selected from the De- partment of Orthopaedics, the Sixth People＇s Hospital affiliated to Shanghai Jiaotong University from June 2005 to January 2006, including 13 males and 6 females aged 24-62 years with an average of 36 years old. There were 3 cases of brachial plexus nerve injury, 3 of median nerve injury, 7 of radial nerve injury, 3 of ul- nar nerve injury and 3 of common peroneal nerve injury, and all the patients received probing nerve fiber restoration. Their main preoperative manifestations were dennervation, pain in limbs, motor and sensory disturbances. All the 19 patients were informed with the therapeutic program and items for evaluation. METHODS： ① Low-frequency pulse percutaneous electric stimulation apparatus： The patients were given electric stimulation with the TERESA cantata instrument （TERESA-0, Shanghai Teresa Health Technology, Co., Ltd.）. The patients were stimulated with symmetric square waves of 1-111 Hz, and the intensity was 1.2-5.0 mA, and it was gradually adjusted according to the recovered conditions of neural regeneration following the principle that the intensity was strong enough and the patients felt no obvious upset. They were treated for 4- 24 weeks, 10-30 minutes for each time, 1-3 times a day, and 6 weeks as a course. ② EMG examination was applied to evaluate the recoveries of recruitment, motor conduction velocity （MCV） and sensory conduction velocity （SCV） before and after treatment. The patients were examined with the EMG apparatus （DIS- A2000C, Danmark） before and after the treatment of percutaneous electric stimulation. ③Standards for evaluating the effects included cured （complete recovery of motor functions, muscle strength of grade 5, no abnormality in EMG examination）, obviously effective [general recovery of motor function, muscle strength of grade 4, no or a few denervation potentials, motor conduction velocity （MCV） and sensory conduction velocity （SCV）], improved （partial recovery of motor function, muscle strength of grade 3, denervation potentials and reinneration potentials, slowed MCV and SCV, invalid （no obvious changes of motor function）. MAIN OUTCOME MEASURES： ① Ameliorated degree of the nerve function of the postoperative patients with peripheral nerve injury treated with percutaneous electric stimulation; ② Changes of EMG examination before and after treatment. RESULTS： All the 19 postoperative patients with peripheral nerve injury were involved in the analysis of results. ① Comparison of nerve function before and after treatment in 19 patients with peripheral nerve injury of different sites： For the patients with radial nerve injury （n=7）, the nerve functions all completely recovered after 8-week treatment, and the cured and obvious rate was 100% （7/7）; For the patients with brachial plexus nerve injury （n=3）, 1 case had no obvious improvement, and the cured and obvious rate was 67% （2/3）; For the patients with common peroneal nerve injury （n=3）, the extension of foot dorsum generally recovered in 1 case of nerve contusion after 4-week treatment, and the cured and obvious rate was 67% （2/3）; For the patients with median nerve injury （n=3）, muscle strength was obviously recovered, and the cured and obvious rate was 100% （3/3）; For the patients with ulnar nerve injury （n=3）, 1 case only had recovery of partial senses, and the cured and obvious rate was 67% （2/3）. Totally 9 cases were cured, 7 were obviously effective, 1 was improved, and only 2 were invalid. After 4 courses, the cured rate of damaged nerve function after four courses was 47% （9/19）, and effective rate was 89% （17/19）.② Comparison of EMG examination before and after treatment： Before and after percutaneous electric stimulation, he effective rates of recruitment, MCV and SCV were 89% （17/19）, 58% （11/19）, 47% （9/19） respectively, and there were extremely obvious differences （P〈 0.01）. CONCLUSION： ①Low-frequency pulse percutaneous electric stimulation can improve the nerve function of postoperative patients with peripheral nerve injury of different sites, especially that the injuries of radial nerve and median nerve recover more obviously. ②Percutaneous electric stimulation can ameliorate the indexes of EMG examination, especially the recruitment, in postoperative patients with peripheral nerve injury.

Treatment time influences the effects of a low-frequency pulsed electric field on synthesis of tyrosine hydroxylase and dopamine in PC12 cells

BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial. OBJECTIVE： To determine tyrosine hydroxylase （TH） expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field （LF-PEF） stimulation, and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors. DESIGN, TIME AND SETTING： A parallel, controlled, cell experiment was performed at the Laboratory of Cell Biology, School of Life Science, East China Normal University, between January and October 2006. MATERIALS： PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China. Nerve growth factor was purchased from PeproTech, USA. The protein kinase A inhibitor, H-89, and mitogen-activated protein kinase kinase inhibitor, U0126, were purchased from Sigma, USA. METHODS： （1） Following routine culture in Dulbecco＇s modified eagle medium, primary PC12 cells were stimulated under LF-PEF （pulse frequency 50.Hz, pulse width 20 μs, peak field strength 1 V/m） for 5, 10, 15, 20, and 30 minutes. （2） Inhibitors （H-89 or U0126, 1 μmol/L） were added 30 minutes before LF-PEF stimulation for 10 minutes. MAIN OUTCOME MEASURES： （1） TH expression was determined by Western blot in PC12 cells at 0.5, 1,2, 3, and 4 days after LF-PEF stimulation. Similarly, DA was measured by high-performance liquid chromatography in media at 2, 3, 4, or 5 days after LF-PEE （2） TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEE RESULTS： （1） Short-term LF-PEF stimulation （5 and 10 minutes） increased TH expression and media DA levels after short-term culture （2 days） （P 〈 0.01）, but both parameters decreased with longer culture （3 4 days） （P 〈 0.01）. Long-term LF-PEF stimulation （15, 20, or 30 minutes） decreased TH and DA synthesis, followed by a rapid increase （P 〈 0.01）. （2） H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes, while the inhibition rate of U0126 was 53.2%. CONCLUSION： Short-term LF-PEF first promotes then inhibits, while long-term LF-PEF first inhibits then promotes, TH and DA synthesis. LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.

A reusable planar triggered spark-gap switch batched-fabricated with PCB technology for medium- and low-voltage pulse power systems

Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems.Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion.Additionally,these switches did not employ any structures in securing internal gas composition,resulting in inconsistent performance under harsh atmospheres.In this work,a novel planar triggered spark-gap switch(PTS)with a hermetically sealed cavity was batched-prepared with printed circuit board(PCB)technology,to achieve reusability with low cost.The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision.The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times.The calculated switch voltage and circuit current were consistent with those derived from real-world measurements.Finally,PCB PTS was used to introduce hexanitrostilbene(HNS)pellets in a pulse power system to verify its performance.

Electro-Pulse-Boring(EPB): Novel Super-Deep Drilling Technology for Low Cost Electricity

The inexhaustible heat deposit in great depths （5-10 km） is a scientific fact. Such deposit occurs around the globe. Thereby, everybody is enabled to generate autonomously clean and renewable energy, ample electricity and heat. The economical exploration and exploitation of this superdeep geothermal heat deposit requires a novel drilling technique, because the currently only deep drilling method （Rotary） is limited to about 5 km, due to the rising costs, depending exponentially on depth. Electro-pulse-boring （EPB） is a valuable option to Rotary drilling. EPB, originally investigated in Russia, is ready to be developed for industrialization. The feasibility of EPB is proven by many boreholes drilled up to 200 m in granite （crystalline）. Estimates show outstanding low costs for drilling by EPB： 100 E/m for a borehole with a large diameter （φ） such as 20 （50 cm）, independent on depth and applicable likewise for sediments and crystalline rocks, such as granite. The current rate of penetration （ROP） of 3 m per hour is planned to be augmented up to 35 m per hour, and again, irrespective whether in sedimentary or crystalline formations. Consequently, a 10 km deep borehole with φ 50 cm will ultimately be drilled within 12 days. EPB will create new markets, such as： （i） EPB shallow drilling for geotechnics, energy piles, measures in order to mitigate natural hazards, etc., （ii） EPB deep drilling （3-5 km） for hydro-geothermics, exploration campaigns etc. and （iii） EPB super-deep drilling （5-10 km） for petro-geothermies, enabling the economic generation of electricity. The autonomous and unlimited supply with cost efficient electricity, besides ample heat, ensures reliably clean and renew- able energy, thus, high supply security. Such development will provide a substantial relief to cope with the global challenge to limit the climate change below 2 ℃. The diminution of fossil fuels, due to the energy transition in order to mitigate the climate change, implies likewise the decrease of air pollution.

可控冲击波震源技术在陕北沙漠区地震勘探的应用

针对现有地震勘探震源存在问题和局限性,创新性地将金属丝电爆炸可控冲击波技术应用于地震勘探中,分析了金属丝电爆炸可控冲击波技术和产生原理。在掌握金属丝电爆炸可控冲击波技术作为地震勘探震源技术的特点和陕北沙漠地区进行现场激发试验的情况下,从理论分析和现场试验验证了金属丝电爆炸可控冲击波技术作为震源技术的可行性。通过对获取的数据进行定量分析,认为可控冲击波技术可作为一种新型震源技术,且在陕北沙漠区煤田地震勘探领域具备较好的应用发展前景。同时,通过总结试验中存在的问题,为下一步的改进提供方向。

基于电磁发射技术的电脉冲铆接设备研制与工艺研究

针对电磁铆接中设备结构体积大、能量转换效率较低等问题,提出了一种电脉冲铆接方法。首先,通过分析电脉冲铆接机理,推导了电能–电磁能–机械能的能量转换过程,并采用有限元建模仿真方法对铆钉电脉冲铆接成形进行了模拟试验,为电脉冲铆接成形的原理分析、设备参数的选择提供依据。然后,设计并研制了一种电脉冲铆接设备,通过仿真方式确定了样机关键参数,并在电路设计基础上实现了脉冲电源与铆枪研制。最后,以充电电压为变量进行了28次电脉冲铆接试验,完成了电脉冲铆接的工艺研究,结果表明,各试验中镦头的高度和直径合格率为100%,电脉冲铆接设备的能量利用率较高。

高压脉冲电场实验交流电源输出电压控制技术研究

常规的高压脉冲电场实验交流电源输出电压控制,主要采用平衡负载电压进行输出电压的谐波控制,忽略了输出电压轴向变量对控制效果的影响,导致控制结果偏差量较大。因此,提出高压脉冲电场实验交流电源输出电压控制技术研究。分析高压脉冲电场实验荷电量以及扩散荷电量等参数,通过矢量相角幅值计算交流电源输出电压的三个轴向变量,构建控制模型,并计算误差补偿值,实现输出电压的控制。实验结果表明:所提控制技术应用后得出的控制结果,表现出的控制偏差量较小,均值仅为0.053,与目标控制效果一致性较高,满足了高压脉冲电场实验中,交流电源输出电压的控制需求。

电脉冲红外成像技术在变电站直流电源系统故障预测中的应用

随着变电站自动化技术的不断进步,直流电源系统作为保障变电站正常运行的关键组成部分,其可靠性和安全性受到极大关注。电脉冲红外成像技术作为一种非接触式的高精度诊断技术,近年来在电力系统中的应用越来越广泛。文章通过深入分析电脉冲红外成像技术的基本原理和特性,结合变电站直流电源系统的运行机制和故障特性,提出一种新的故障预测模型。

纳秒脉冲电流检测技术的研发

目的纳秒脉冲电场治疗设备的临床应用,需要准确稳定获取脉冲输出电流幅值。由于治疗用脉冲前沿陡、脉宽短、电磁干扰强,故本研究旨在研发一种新型的脉冲电流检测技术,以实现脉冲电流检测功能。方法采用高性能隔离式电流传感器进行脉冲电流采样,电流信号调制衰减后通过阻抗匹配和差分的方式进行传输,现场可编译门阵列(Field Programmable Gate Array,FPGA)缓存模数转换后的电流数字量信号,以通讯方式传输到微控制芯片进行电流数据的分析处理。采用多层板的印制电路板(Printed Circuit Board,PCB)设计,增强抗干扰性。结果静态直流测试和实际负载下的动态脉冲测试误差均≤5%,实现了纳秒级别的稳定采样。结论该纳秒脉冲电流检测模块能满足医用级治疗设备的应用要求且方便集成,具有较强的临床实用性。

低频脉冲电刺激技术结合温针灸治疗产后尿潴留临床观察

目的探讨低频脉冲电刺激技术结合温针灸治疗产后尿潴留的临床效果。方法2020年4月—2022年1月,选取徐州市妇幼保健院收治的82例产后尿潴留患者,随机分为治疗组(41例)与常规组(41例)。常规组予以低频脉冲电刺激技术治疗,治疗组在常规组基础上联合温针灸治疗,2组疗程均为3 d。比较2组患者的临床疗效、视觉模拟量表(VAS)评分及首次排尿时间、膀胱残余尿量以及并发症发生情况。结果治疗组的临床总有效率为97.56%(40/41),显著高于常规组的80.49%(33/41)(P<0.05)。与常规组比较,治疗组首次排尿时间显著更短、膀胱残余尿量显著更少、VAS评分显著更低(P<0.05)。并发症方面,与常规组比较,治疗组患者的留置尿管率、再次尿潴留率显著更低(P<0.05)。结论对于产后尿潴留,采用低频脉冲电刺激技术结合温针灸治疗,可取得显著的效果,能够明显降低患者小腹疼痛程度,缩短患者首次排尿时间,减少患者膀胱残余尿量,减少并发症发生,值得推广。

基于盆底解剖三代电生理技术治疗盆底肌过度紧张患者的临床疗效观察

目的探讨基于盆底解剖三代电生理技术治疗盆底肌过度紧张的临床疗效。方法回顾性分析2022年10月至2023年5月在暨南大学附属第一医院就诊的36例男性患者,年龄21~82(48.47±19.68)岁,均诊断为盆底肌过度紧张,临床表现以尿等待、尿线细、尿中断、尿潴留等排尿困难为特征,可出现尿频、夜尿,部分伴有排粪困难,直肠指检肛门括约肌紧张。彩超前列腺大小23~43(32.42±5.24)g。其中3例患者因尿潴留留置尿管。每例患者在电生理技术治疗前均口服盐酸坦索罗辛缓释胶囊(0.2 mg,每晚1次)或赛洛多辛胶囊(4 mg,每日2次)2~4周,临床症状没有改善。26例患者伴有排大便困难,采用经皮低频脉冲电刺激治疗。治疗前给予每例患者红外线热成像检测,可视化选择患者个体化电治疗参数,精准治疗,每完成10次治疗,重复红外线热成像检测,调整电治疗参数。采用配对t检验、χ^(2)检验。结果患者电刺激治疗后尿等待时间[(2.39±1.44)s]短于治疗前[(41.21±12.25)s],最大尿流率(Q_(max))[(16.06±1.90)ml/s]高于治疗前[(7.46±1.39)ml/s],尿频次数[(6.00±0.71)次]低于治疗前[(10.76±1.50)次],夜尿次数[(0.45±0.50)次/晚]少于治疗前[(2.06±1.22)次/晚],差异均有统计学意义(均P<0.0001)。尿潴留患者治疗后均顺利拔除尿管,排尿顺畅。排大便困难治疗前发生率为72.0%(26/36),治疗后发生率为0。结论在采用α1受体阻滞剂治疗排尿困难后无效,伴有排大便困难时,要考虑盆底肌过度紧张。三代电生理技术治疗盆底肌过度紧张获得满意的近期临床疗效,随着治疗例数增加,远期疗效将得到进一步证实,为治疗盆底肌过度紧张提供了一种可靠的新方法。

脉冲电场技术通过氧化应激途径诱导营养物质合成和杀灭微生物的研究进展

脉冲电场(Pulsed Electric Field,PEF)技术是一种新兴非热食品加工技术,由于PEF对食品质量损伤小且能杀灭食品中有害微生物所以被广泛应用。PEF通过氧化应激途径激活植物类食品的营养物质合成途径,诱导营养物质合成、提高食品质量,然而关于这一领域的研究较少。PEF发生了氧化应激反应造成了营养物质合成与积累,植物类食品受到PEF刺激后产生大量活性氧(Reactive Oxygen Species,ROS),ROS会激活代谢物合成途径最终合成蛋白、多酚、硫代葡萄糖苷和胡萝卜素等物质;ROS聚集在微生物的细胞膜上会造成蛋白表达异常,损害脂质层和脱氧核糖核酸(Deoxyribonucleic Acid,DNA),最终导致微生物失活。

基于电脉冲红外成像技术的变电站电气设备热故障识别方法

为提高电气设备热故障识别准确性,减少由热故障导致的电网供电服务异常事故发生次数,引进电脉冲红外成像技术,以某变电站为例,设计一种针对电气设备的热故障全新识别方法。设定电脉冲辐射线的发射率,实现基于电脉冲红外成像技术的电气设备温度场图像获取。同时,利用均值法、均值滤波法进行图像的灰度化、滤波处理,完成红外图像处理后,引进相对温差法进行图像中高温区域的提取,以此实现对电气设备在运行中热故障的诊断。实验结果表明,设计的热故障识别方法应用效果良好,可以确保识别结果与电气设备实际故障结果高度一致,精准排查电气设备在运行中的故障现象,提高电气设备运行的可靠性和安全性。

电动汽车充电桩快速充电技术研究

文章在分析电动汽车的充电模式及充电方法的基础上,提出了一种带负脉冲快速充电技术,并对该技术的充电原理进行分析,之后通过试验对比的方式,对这一充电技术的充电效率进行验证。试验结果证明,相较于大电流充电、恒流充电方法,带负脉冲充电技术可提高电池充电容量,减少充电时长,是一种充电效率较高的充电方式。

基于SPWM调制技术的采集终端备电系统设计

以往的采集终端备电系统虽然能在电网停电的状态下持续供电,但其电能转化率低,造成了很大的资源浪费。在上述背景下,设计基于正弦脉宽调制(Sinusoidal Pulse Width Modulation,SPWM)技术的采集终端备电系统。在硬件设计上,设计了备电光伏板和采集电源信息继电器;在软件设计上,利用SPWM调制技术转化率高、低成本、高效能的特点设计了系统的逆变输出模块,结合发电模块和蓄电模块,完成了采集终端备电系统的设计。通过系统实验表明,设计的备电系统电能转化率远高于以往的备电系统,电能转化率更高。

高压脉冲电场设备及其在食品非热处理中的应用

为较全面了解高压脉冲电场(PEF)食品非热加工技术,总结了清华大学在PEF上的开发和应用研究,对PEF技术的理论研究和工业化发展现状进行了综述。首先分析了清华大学4代高压脉冲电场系统的电源结构拓扑和性能以及处理室的结构特性,其次对相关系统在液态食品处理领域的应用研究进行了总结介绍。研究结果表明,经过近10a的努力,清华大学所设计开发研制的高压脉冲电场果汁非热处理系统可满足实验室应用需求,并正向工业中试规模应用努力。

面向化石能源开发的电爆炸冲击波技术研究进展

针对化石能源开发中储层改造技术的局限性,创新性地提出了重复脉冲强冲击波增透储层新技术。分析了水中放电、金属丝电爆炸和电爆炸等离子体驱动含能混合物产生冲击波的3种机理。介绍了冲击波作用储层的机理研究和现场应用结果,从理论、实验和现场实践验证了冲击波技术增透储层的可行性。结果表明,以电爆炸等离子体驱动含能混合物产生更强的和区域可控的冲击波,可针对储层做单点多次、分段式的增透改造,在化石能源开发中的意义重大。

非热物理加工新技术对食品品质的影响及应用

阐述了超高压技术、辐照技术、脉冲电场技术、超声波技术等非热物理加工新技术的定义及特点,并综述了这些新技术对食品成分的影响及其在食品加工中的应用。

用高压脉冲电场技术快速提取苹果渣果胶

将高压脉冲电场技术用于提取苹果渣中的果胶。通过单因素试验和正交试验得出了提取苹果渣果胶的最佳工艺参数:电场强度为15 kV/cm、pH值为3、脉冲数为10、料液比为1∶19、温度为62℃,该条件下苹果渣果胶得率最高为14.12%。将该技术与酸提取法、草酸铵法、超声波提取法、微波提取法进行了对比研究,发现高压脉冲电场方法是最为有效的提取果胶的方法。

变频调速技术的发展及其在电力系统中的应用

从电力半导体、控制技术和主电路拓扑结构等方面综述了变频调速技术的发展历史和现状,并总结了在变频控制中的主要控制技术;分析了高压变频调速技术的发展动态和几种实现方案的技术特点对比情况;指出变频调速技术在未来的发展趋势。最后介绍了变频调速技术在电力系统中节能降耗、改善工艺和控制性能等方面的应用。