Preoperative microcoil embolization of the common hepatic artery for pancreatic body cancer

AIM:To evaluate safety and feasibility of microcoil embolization of the common hepatic artery under proper or distal balloon inflation in preoperative preparation for en bloc celiac axis resection for pancreatic body cancer.METHODS:Fifteen patients(11 males,4 females;median age,67 years) with pancreatic body cancer involving the nerve plexus surrounding the celiac artery underwent microcoil embolization.To alter the total hepatic blood flow from superior mesenteric artery(SMA),microcoil embolization of the common hepatic artery(CHA) was conducted in 2 cases under balloon inflation at the proximal end of the CHA and in 13 cases under distal microballoon inflation at the distal end of the CHA.RESULTS:Of the first two cases of microcoil embolization with proximal balloon inflation,the first was successful,but there was microcoil migration to the proper hepatic artery in the second.The migrated microcoil was withdrawn to the CHA by an inflated microballoon catheter.Microcoil embolization was successful in the other 13 cases with distal microballoon inflation,with no microcoil migration.Compact microcoil embolization under distal microballoon inflation created sufficient resistance against the vascular wall to prevent migration.Distal balloon inflation achieved the requisite 1 cm patency at the CHA end for vascular clamping.All patients underwent en bloc celiac axis resection without arterial reconstruction or liver ischemia.CONCLUSION:To impede microcoil migration to the proper hepatic artery during CHA microcoil embolization,distal microballoon inflation is preferable to proximal balloon inflation.

Endovascular Embolization of Pseudoaneurysms Complicating Pancreatitis Using Microcoils: Case Series

Purpose: To determine whether endovascular embolization of pseudoaneurysms complicating pancreatitis with microcoils was associated with better therapeutic outcome. Materials and Method: The prospective clinical study was carried out in the Department of Interventional Radiology for a period of 2 years extending from May 2010 upto August 2012 on 16 male patients in the age group of about 30 - 55 years, with each one of them having vascular complications as a sequel to pancreatitis, after obtaining well informed written consent from each one of them. Results: The outcome of the procedure was judged by the following parameters—a) Restoration of the blood pressure of the patient;b) Cessation of the hemetemesis and malena;c) Reduction in abdominal pain and discomfort and d) Overall improvement in the general condition of the patient. Each of the patients had been on follow up for at least 6 months, except 2 of them, with no new complaints in any of them. The procedure related mortality was none. Conclusion: Vascular complications of pancreatitis need immediate and accurate diagnosis and prompt treatment. Micro coil embolisation, is a minimally invasive technique which helps to exclude the pseudoaneurysm from the circulation and thus reduces the scope for massive life threatening internal hemorrhage, and is a better alternative to surgery.

Endovascular embolisation of Giant Ruptured Proximal Splenic Arterial Pseudoaneurysm Using Microcoils &Glue: Case Report

Splenic artery aneurysms (SAA) are third most common intra-abdominal aneurysm (after aneurysms of the abdominal aorta and iliac arteries). A splenic artery aneurysm larger than 3 cm is even rare. Splenic artery aneurysms are fatal vascular lesions if ruptured. The incidence of rupture is increased in larger aneurysms. Transcatheter arterial embolization is an alternative method of treatment in a patient with splenic arterial aneurysm which has relative lower morbidity and mortality than surgical procedures. Here, we report a case of giant ruptured proximal splenic artery pseudoaneurysm detected by contrast enhanced computed tomography (CECT) & referred to Interventional Radiology for Transcatheter arterial embolisation.

Study on the impedance of aligned carbon microcoils embedded in silicone rubber matrix

This paper reports that carbon microcoils are grown through a chemical vapour deposit process, they are then embedded in silicone rubber, and manipulated to parallel with each other along their axes in the resulting composite. The impedance ｜Z｜ as well as phase angle 8 of both the original carbon microcoil sheets and the aligned carbon microcoil/silicone rubber composites are measured. The results illustrate that carbon microcoils in different forms show different alternating current electric properties. The aligned carbon microcoils in the composites show stable parameters for f 〈 104 Hz but a sharp decrease in both ｜Z｜ and θ for frequencies 〉 10^4 Hz, which will also change as the carbon microcoils are extended. But, the original sheets have a pure resistance with their parameters stable throughout the entire alternating current frequency range investigated.

High-density stacked microcoils integrated microminiaturized electromagnetic vibration energy harvester for self-powered acceleration sensing

With the rapid development of microelectronics and flexible electronics technology,self-powered sensors have significant application prospects in human-machine interface systems and Internet of Things.However,piezoelectric-and triboelectricbased sensors have low current output and are easily affected,while electromagnetic-based sensors are difficult to miniaturize.This work proposes a high-density stacked microcoil integrated microminiaturized electromagnetic vibration energy harvester(EVEH).The double-layer high-density microcoil is fabricated on both sides of the flexible polyimide substrate interconnected via the central through-hole.Owing to reduced single coil line width,line spacing,and stacked structure,the number of turns can be substantially enhanced.Moreover,the relative position of the coils and magnet has a considerable influence on the performances;due to the huge change rate in magnetic flux when the coil is placed in the radial direction of the magnet than in the axial direction,the open-circuit voltage in the radial direction is 10 times greater.The microcoil can maintain good performance at high,low temperatures and under bending conditions.When the distance between the ends of the coil changes from 2 to 20 mm in 2 mm steps,the bending angle of the coil changes from 45°to 270°in 45°steps;furthermore,when the coil is exposed to-40and 60℃conditions,the coil resistance is maintained at approximately 447Ω.The peak open-circuit voltage of three-piece microcoils reaches 0.41 V at 4 Hz under 2g,and the output voltage and current increase with an increasing number of stacked layers.These excellent properties indicate that EVEH can be used for self-powered acceleration sensing.The sensitivity is measured to be 0.016 V/(m/s^(2))with a correlation coefficient of 0.979 over the acceleration range of 1–18 m/s^(2).Thus,the developed microminiaturized EVEH has enormous potential for self-powered sensing applications in confined spaces and harsh environments.

基于平面微型线圈的单线电能传输系统研究

研究了由两个平面特斯拉线圈构成的微型单线电能传输(SWPT)系统,在Comsol软件中对该系统进行建模和参数设定,通过仿真实验,确定了平面特斯拉线圈在SWPT方向的可实现性。重点研究了SWPT系统在不同传输距离、不同传输频率情况下对传输效率的影响。并对SWPT系统模型各参数进行调整,通过改变模型初级和次级匝数,对系统传输效率进行分析。此处通过仿真实验,确定了SWPT系统最大传输效率下的各项系统参数,并通过实物实验验证了系统性能。

Study on intraluminal embolization with microcoils treating traumatic pseudoaneurysms in common carotid artery in rabbits

Objective: To evaluate the long-term effect of endovascular occlusion with microcoils on traumatic pseudoaneurysms (TPAs) in the common carotid artery in rabbits.Methods: TPAs in the right common carotid artery were surgically made in 16 rabbits. At 3-4 weeks after operation, the survived 12 models were randomly divided into a control group (n=3) with no treatment and an experimental group (n=9), in which TPAs were intraluminally embolized with microcoils and corresponding therapy was given. Three months after embolization, the TPAs were examined with digital subtraction angiography and pathology. Results: The 3 rabbits in the control group all died of rupture of TPA. Among the 9 TPAs occluded with microcoils, 4 were completely occluded, 4 were partially occluded, and 1 was excluded due to the microcoils migrating into the parent artery. Three months after embolization, the 4 TPAs which were completely occluded remained obliterated as determined by digital subtraction angiographic findings. The parent artery remained unobstructed and the structure of the TPAs were replaced by a mass of scar tissues. The 4 TPAs which were partially occluded remained unruptured and the microcoils were compressed.Conclusions: The lumen in TPA can be completely occluded by microcoils and the parent artery is unblocked. Partial occlusion of the lumen can also prevent the rupture of TPA.

碳线圈阵列的无催化剂制备与微波吸收性能

轻质高性能碳基吸波材料的高效低成本制备是一个巨大的挑战。研究以生物质体内的维管束为模板,在无催化剂条件下成功制备了一种新型碳微米线圈阵列吸波剂。这种碳微米线圈阵列由碳微米线圈取向排列而成,包含有大孔通道、螺旋狭缝孔以及表面微孔构成的分级多孔结构。这种独特的多孔阵列结构体现了良好阻抗匹配性,有利于入射电磁波充分进入吸波体内部,增大电耦合和磁耦合作用面积,同时增加电磁波的反射和散射损耗路径,有利于电磁波吸收损耗。碳线圈表面富氧官能团提高了丰富的极化中心,增强了微波吸收的极化损耗。吸波性能结果表明,碳微米线圈阵列是一种轻质、强吸收的微波吸收体,在填料比为10%(质量分数)时,其最大有效吸收带宽(f_(e))可达5.5 GHz;而填料比为15%(质量分数)时,最大反射损耗(RL_(min))为-45.09 dB。这种维管束基碳线圈阵列的无催化剂制备方法可以在其他生物质中应用。

微弹簧圈五步扫描定位法在肺部多发结节诊治中的应用

目的:探讨微弹簧圈五步扫描定位法在肺部多发结节诊治中的应用及意义。方法:选择2017年6月—2022年12月在清华大学附属垂杨柳医院胸外科进行手术治疗的肺结节患者337例(387个肺内病变),根据术前需定位的结节个数分为对照组(单发,n=297)与观察组(多发,n=40),所有患者均采用微弹簧圈五步扫描定位法进行定位。应用SPSS 21.0统计学软件比较两组患者定位的成功率与并发症。结果:两组病变位置、病变性质、病变大小、病变深度比较,差异有统计学意义(P<0.05)。观察组定位成功率及并发症发生率与对照组比较,差异均无统计学意义(P>0.05)。穿刺定位后观察组出现气胸7例(17.50%),对照组出现气胸32例(10.77%),两组比较差异无统计学意义(P>0.05)。两组均无咯血、空气栓塞及血胸等并发症。两组手术均以胸腔镜亚肺叶切除为主,无中转开胸。两组病变均以早期病变为主。两组患者均痊愈出院,无围术期并发症。结论:使用微弹簧圈五步扫描定位法进行术前定位,肺部多发结节可获得与孤立性结节同样的安全性及有效性。

Fabricating a Micro Electromagnetic Actuator with High Energy Density

This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.

输卵管积水的栓塞治疗

目的探讨和评价输卵管积水栓塞治疗方法的可行性。方法在X线透视监视下,行输卵管选择性插管,将微弹簧圈通过微导管送入输卵管近端,达到栓塞输卵管的目的。结果输卵管栓塞98例患者,双侧输卵管栓塞66例,单侧输卵管栓塞32例,共栓塞164侧输卵管,插管均一次性成功。输卵管栓塞后1个月行子宫输卵管造影术,显示有效者164侧为100%,其中显示最佳效果者136侧输卵管,占82.9%;无效者为0。结论输卵管栓塞的介入治疗是行之有效的方法,与目前采用的方法相比,无手术并发症,简便,安全,经济,对卵巢功能无影响。

双能量CT联合金属伪影削减算法显示微弹簧圈定位肺结节

目的评价双能量能谱CT(DESCT)扫描获得的虚拟单色谱(VMS)图像联合金属伪影削减(MAR)算法在CT引导微弹簧圈定位肺结节中的应用价值。方法选取80例CT引导微弹簧圈定位的肺结节患者,微弹簧圈置入后,对其行DESCT扫描。选择最佳光子能量水平,在最佳能量水平重建VMS图像及经MAR算法处理的VMS图像(VMS+MAR),比较VMS、VMS+MAR图像质量主观评分的差异。结果选择74keV为最佳能量水平。74、90、110、140keV VMS+MAR图像质量优于50keV图像(P均<0.05);74、90、110、140keV水平VMS+MAR图像质量评分差异均无统计学意义(P均>0.05)。74keV VMS+MAR图像质量优于VMS图像(P<0.05)。2名观察者主观评分一致性较好(Kappa值=0.78)。结论 74keV VMS图像联合MAR算法可有效抑制微弹簧圈金属伪影,清晰显示肺结节。

介入微弹簧圈栓塞术治疗颅内动脉瘤

目的探讨介入微弹簧圈栓塞治疗颅内动脉瘤技术,评价临床疗效。方法采用介入方法微弹簧圈栓塞术,对114例119枚颅内动脉瘤进行栓塞治疗。临床表现为自发性蛛网膜下腔出血者107例。119枚动脉瘤中宽颈动脉瘤24枚,其中5枚采用支架辅助技术进行栓塞;2枚椎动脉梭形动脉瘤均进行了隔断绝栓塞术。结果119枚动脉瘤中118枚成功栓塞,其中完全致密闭塞72枚(60.5%),接近完全闭塞30枚(25.2%)、大部分闭塞13枚(10.9%),部分闭塞3枚(2.5%),1枚未能栓塞(0.8%)。6例前交通动脉瘤患者出现术中动脉瘤破裂,均继续栓塞后达到了基本致密的填塞,5例基本康复,1例留下残疾。术后1个月内死亡3例(2.5%),均为Hunt-Hess分级Ⅳ～Ⅴ级的患者,死于原先的严重出血或继发的严重脑血管痉挛。结论介入微弹簧圈栓塞治疗颅内动脉瘤是安全、有效的临床技术,积极、及时的栓塞治疗可有效防止动脉瘤再破裂。

微弹簧圈定位在胸腔镜肺小结节切除术中的应用

目的探讨术前CT引导下微弹簧圈定位在胸腔镜孤立性肺小结节切除术中的应用价值。方法 2014年5月~2016年4月,对21例单发肺部小结节病灶经术前定位后行胸腔镜手术切除。结节直径7~21(10.3±8.0)mm,距离脏层胸膜深度5~23(10.2±4.3)mm。术前1日在CT引导下行"拖尾法"微弹簧圈术前定位,胸腔镜下行病灶楔形切除术,送冰冻病理,如为恶性继续行胸腔镜下肺叶切除加纵隔淋巴结清扫术。结果全组21例肺小结节均成功经皮肺穿刺置入微弹簧圈。定位并发症为无症状气胸3例,均无需处理。胸腔镜术中发现微弹簧圈脱位3例,定位成功率85.7%(18/21)。21例均行胸腔镜手术切除。病理确诊原位癌5例,腺癌11例,非典型腺瘤样增生1例,炎症2例,炎性假瘤1例,肺内转移瘤1例。结论 CT引导下微弹簧圈定位用于肺内小结节术前定位是一种简单、直观、有效、精确的方法,值得推广。

螺旋形炭纤维的吸波性能(英文)

通过气相催化裂解法分别制得了螺径约为4μm、螺距为0.5μm^0.8μm的炭纤维(简称为coils-A)和螺径为20μm左右、螺距为1μm^4μm的炭纤维(简称为coils-B)。以coils-A和coils-B为掺杂体与石蜡制成复合材料在8.2GHz^124GHz范围内通过反射传输系统测量其电磁参数,结果表明该等微米级螺旋形炭纤维磁损耗为零,其中coils-B的介电参数的虚部及其损耗正切值tanδε较coils-A的高。分别以coils-A和coils-B为手性掺杂体制得填充有手性材料的夹芯蜂窝板复合材料,研究发现coils-A的吸波效果较好,在10GHz^15GHz的范围内对电磁波的反射衰减量大于10dB,在4.6GHz^18GHz的范围内对电磁波的反射衰减量均大于5dB,在12.4GHz时最大的反射衰减量为18dB,其结果与藉由电磁参数所预测的结果相反。经计算,coils-A的手性参数ξ较大。因此,手性参数ξ对于提高吸波性能的影响大于介电参数ε的影响。

电镀Ni膜催化生长螺旋纳米碳纤维及其电磁性能研究

采用电镀工艺制备催化剂Ni膜,以化学气相沉积方法合成螺旋纳米碳纤维,通过扫描电镜(SEM)、X射线衍射(XRD)和偏光显微镜对螺旋纳米碳纤维的形态和结构进行表征。研究了电镀时间、电镀电流对螺旋纳米碳纤维生长的影响;并通过波导法对制备出的螺旋状纳米碳纤维测试在12.4～18GHz频段的电磁参数,考察其吸波性能。

基于微线圈阵列的多道神经电刺激信号透皮传输的初步实验研究

通过探索微线圈阵列实现多路神经电刺激信号透皮传输的可行性及影响传输效率的相关因素。根据电磁耦合原理,设计了包括脉冲发生、高频振荡、AM调制、功率放大、选频等刺激信号发射电路,信号接收电路,以及用于多通道信号耦合的微线圈阵列和相应实验测试装置。实验中对电路的性能以及线圈发生横向失配和角形失配时电路的可靠性进行了测试,在此基础上设计了2×2阵列的多通道传输装置。结果表明在调谐网络的作用下通道间信号的干扰较小,各通道输出信号能满足神经电刺激的要求。该方法经试验验证具有可行性,可用作各类植入式医疗仪器刺激或者控制信号的多通道传输装置,具有广泛的应用前景。

电解可脱弹簧圈联合微弹簧圈栓塞治疗脾动脉瘤的临床应用评价

目的探讨电解可脱弹簧圈（guglielmidetachablecoils，GDC）联合微弹簧圈栓塞治疗脾动脉瘤的可行性、安全性及操作要点。方法回顾解放军总医院血管外科2012年1月-2013年3月采用GDC联合微弹簧圈治疗8例脾动脉瘤患者的临床资料，其中2例脾动脉瘤位于脾动脉起始部，3例位于脾动脉中段，3例位于脾门处。瘤体平均直径（24±3．4）（20～28）mm。结果全部病例均一次性栓塞成功，共使用GDC33枚，普通弹簧圈58枚，未出现手术相关并发症。平均随访（11±4．5）（5～181个月，脾动脉瘤未见血流通过，无脾梗死发生。结论GDC结合微弹簧圈栓塞脾动脉瘤安全可行，远期效果需进一步随访观察。

基于MEMS工艺的高能量密度微电磁驱动器

提出了制作高能量密度电磁驱动器的工艺方法。利用微机械(MEMS)工艺在硅片上得到多匝平面线圈和磁芯的掩模图形,接着沉积种子层铜(Cu),然后对种子层进行整体Cu的电铸;当种子层生长到20μm左右时,剥离硅片表面的镀层并用光刻胶保护磁芯位置的镀层;再用沿线电铸的方法对线圈进行电铸;最后保护制作好的线圈镀层,电铸NiFe合金材料。在10 mm×10 mm×0.38 mm的硅片上,制作出线圈匝数22×2(铜线截面积60μm×60μm、总长度达1 164 mm)、NiFe合金磁芯尺寸为3mm×3 mm×0.2 mm的高能量密度微型电磁驱动器。把这种微型驱动器应用于无阀微泵做驱动实验:通入0.3 A的正弦电流时,微驱动器产生约50 mN的电磁力。实验结果表明:这种型微电磁驱动器在相同的输入功率下,比同类其他微电磁驱动器具有更高的能量密度,能产生更大的电磁驱动力。

颅内动脉瘤栓塞治疗后数字减影血管造影随访研究

目的探讨颅内动脉瘤栓塞术后再通、出血等问题及数字减影血管造影(DSA)随访的必要性。方法选择用GDC或EDC、MDS、Matrix微弹簧圈行血管内栓塞的颅内动脉瘤患者102例,共114个动脉瘤,112个动脉瘤行血管内栓塞,2例多发性动脉瘤患者各有1个小动脉瘤未行栓塞。随访时间为术后1个月至6．5年,平均10．5个月。随访方法为DSA,将随访时的DSA资料与栓塞术后即刻DSA资料进行对比分析。结果初始治疗的动脉瘤闭塞率为100%的58个(51．79%),≥95%的37个(33．04%),＜95%的17个(15．17%)。栓塞治疗后弹簧圈稳定的动脉瘤87个(77．68%),残腔体积缩小6个(5．36%),再通19个(16．96%)。采用GDC或EDC栓塞的90个动脉瘤中,14个再通(15．56%)。闭塞100%、≥95%和＜95%的动脉瘤,再通率分别为4．08%、26．67%和36．36%,三者之间差异有极显著性(P＜0．01)。对术后再通的动脉瘤,9个及时补充GDC栓塞后均未发生再出血,而继续观察的5个动脉瘤中,有1个不全闭塞者发生迟发性再出血。随访结果,经MDS栓塞治疗的18个动脉瘤中,5个再通。采用Ma- trix微弹簧圈或Neuroform支架+Matrix微弹簧圈治疗的4个动脉瘤,无论是近乎完全闭塞还是不完全闭塞,DSA均显示动脉瘤完全闭塞。结论颅内动脉瘤栓塞术后再通与初始治疗的闭塞程度、栓塞材料等因素有关。对闭塞不完全的动脉瘤,应通过DSA进行随访,若明显再通,需及时补充栓塞。