三维电磁导管标测系统指导射频消融治疗室性心律失常

探讨室性心律失常运用三维电磁导管标测系统指导射频消融治疗在临床效果及有效率方面的优势。方法 试验对象的收集时间为2019年7月至2023年7月,56例流出道室性心律失常全部来源于本院,按照双盲法进行28例/组的分组,其中对照组中的患者以常规的方法进行射频消融治疗指导操作,研究组中的患者则在三维电磁导管标测系统指导下进行射频消融治疗。对比两组心腔内电生理检查及 CARTO指导下心内电生理标测、消融结果评价、手术相关指标、临床效果、不良反应发生情况等比较。结果 研究组所得的各个指标的数据均优于对照组,组间差异均有统计学意义,P<0.05。结论 选择三维电磁导管标测系统指导射频消融治疗方式进行流出道室性心律失常的治疗,不仅成效显著,安全性高,且有利于促进生活质量提升,保证满意度,改善预后,值得借鉴和进一步推广。

评估三维电磁导管标测系统指导局灶性房性快速心律失常射频消融的临床价值

目的探讨三维电磁导管标测系统(Carto)指导导管射频消融治疗局灶性房性快速心律失常(简称房速)的临床价值。方法我院2007年4月至2009年4月共13例房速患者接受治疗,男性7例,女性6例,年龄(42.2±10.2)岁,其中3例为常规消融失败患者。对所有患者应用Carto标测实时重建房速发作时三维电激动图,判断房速起源部位及类型,采用冷盐水灌注导管在最早激动点或关键峡部消融。结果13例房速均为局灶性房速,12例消融成功,1例右心耳体部房速消融失败。7例房速在希氏束或冠状静脉窦(CS)近端记录到显著提前的A波,电解剖标测和消融证实房速起源于上腔静脉口部3例、右心耳体部1例、CS口部及其附近3例。3例房速在CS电极远端记录到明显提前的A波,消融结果证实房速起源于左心耳后壁1例、左上肺静脉开口部2例。3例房速在希氏束和CS近端记录到相对提前的A波,消融证实房速起源于右下肺静脉口部2例、主动脉无冠窦内1例。随访2～24个月,其中1例术后3周复发,再次消融成功。3例术前显著右心扩大者,术后3个月内2例心脏大小恢复正常,1例心脏无显著变化。结论Carto标测房速起源及类型准确快速,能安全、有效指导消融,提高成功率,特别对常规方法消融失败者很有帮助。

左房房性心动过速三维电磁导管标测系统(Carto)标测与射频消融

目的 探讨左房房性心动过速 (房速 )三维电磁导管标测系统 (Carto)系统标测特点及射频消融价值。方法 9例左房房速患者 ,应用Carto系统标测左心房 ,实时重建左房三维电解剖图 ;根据电解剖图 ,判断房速类型 :局灶性或大折返性房速 ;于心房最早激动点处或折返环的关键峡部消融。结果 9例患者中共有 10个房速。在冠状静脉窦 (CS)电极中、远端或近端均记录到相对提早A波 ;9个房速为局灶性房速 ,激动图显示最早激动点位于肺静脉口部 (5个 )、左房后壁 (2个 )、左心耳口部 (1个 )、左心耳体部 (1个 ) ;1个为大折返性房速 ,折返经过右上肺静脉口部与卵圆窝之间关键峡部。 8个局灶性房速在上述最早激动点处消融 ,均成功终止房速 ,1个左心耳体部房速消融失败 ;大折返性房速于关键峡部行线性消融 ,获成功 ;随访 6～ 30个月 ,其中 1例局灶性房速术后次日复发 ,再次消融成功 ;无并发症 ;成功病例手术时间为 90～ 14 0min ,X线照射时间为 8～ 16min。结论 本组结果提示 ,应用Carto系统标测左房房速 ,判断房速类型准确、快速 ;指导消融安全、有效 ,可减少X线照射时间 ,进一步提高消融成功率 ,特别是对于常规方法消融失败病例尤有帮助。

特发性室性心动过速12例的电磁解剖标测系统标测和消融

目的评价电磁解剖标测系统(Carto)标测和指导射频消融在治疗特发性室性心动过速的临床应用价值。方法入选12例特发性室性心动过速患者,年龄(33±12)岁。心动过速周期(370±95)ms。室性心动过速持续发作时,7FNavi-Star在相关心室标测,实时重建心腔三维电解剖图,右心室室性心动过速在右心室流出道详细标测,根据激动图上最红色区域为较早激动部位,结合大头导管记录心室波最早、且起搏时体表12导联图形与心动过速一致处,作为消融靶点。左心室室性心动过速在间隔部细标,标识较体表QRS波及His束电位提前的P电位处,作为靶点。温控60℃放电消融。以基础态及静脉滴注异丙肾上腺素反复电生理检查.不可诱发室性心动过速作为成功消融终点。结果12例均成功消融,其中右心室室性心动过速7例,均位于右心室流出道前中间隔部,左心室室性心动过速5例,起源于左心室后中间隔4例、中下间隔近心尖部1例。1例左心室室性心动过速于心动过速在左心室后中间隔处标测时,室性心动过速终止,后标志此处作为靶点,放电消融成功。手术时间为(102±25)分钟,曝光时间为(11±7)分钟。随访6～18个月,无复发病例。结论Carto系统通过磁场标测定位,结合心内电图重建室性心动过速时心室电激动图,可有效快速寻找最早激动点或P电位处作为消融靶点,进行电解剖标测,并可在标测导管机械损伤终止室性心动过速处标志,结合起搏标测,作消融参考点指导消融,治疗特发性室性心动过速安全有效。

三维电磁导管标测系统指导射频消融治疗房性快速心律失常患者的临床效果

目的:观察三维电磁导管标测系统指导射频消融治疗房性快速心律失常患者的临床效果。方法:选取60例房性快速心律失常患者为研究对象,采用随机数字表法分为观察组和对照组,每组30例。对照组予以常规方法指导射频消融治疗,观察组予以三维电磁导管标测系统指导射频消融治疗,比较两组消融成功率、手术指标、不良反应发生率及治疗总有效率。结果:观察组消融成功率为96.67%,高于对照组的73.33%,差异有统计学意义(P<0.05);观察组手术时间和住院时间均短于对照组,差异有统计学意义(P<0.05);观察组不良反应发生率为6.67%,低于对照组的26.67%,差异有统计学意义(P<0.05);观察组治疗总有效率为96.67%,高于对照组的73.33%,差异有统计学意义(P<0.05)。结论:三维电磁导管标测系统指导射频消融治疗房性快速心律失常患者,可提高治疗总有效率和消融成功率,缩短手术时间和住院时间,以及降低不良反应发生率,其效果优于常规方法指导射频消融治疗效果。

先天性心脏病外科手术后切口性房性心动过速三维电磁导管标测及射频消融

目的 探讨先天性心脏病外科手术后切口性房性心动过速 (房速 )三维电磁导管 (即Carto)标测特点及射频消融价值。方法 5例切口性房速患者 ,应用Carto系统标测右心房 ,实时重建心腔三维电解剖图 ,标识瘢痕区 ,观察电势图、传导图 ,于折返所经过的关键峡部作线性消融。结果 4例房速呈持续性 ,1例 (三房心 )术中不能诱发。电势图示低电压区主要分布于右房游离壁 ,在右房中侧壁下侧壁分别标测到瘢痕区 1(S1)和瘢痕区 2 (S2 )。 4例持续性房速发生机理与折返有关 ,折返环位于低电压区 ,中心解剖障碍区均为中侧壁瘢痕区 1,3例折返经过S1～S2 ,1例经过S1～三尖瓣环之间的关键峡部 ;于上述关键峡部消融 ,均获成功。三房心患者 (未诱发心动过速 )于S1～S2及三尖瓣环～下腔静脉之间行线性消融 ,无并发症。随访 2～ 2 4个月 ,其中 1例 (三房心 )于术后 1个月出现不典型心房扑动。结论 提示先天性心脏病术后房速的发生机理与折返有关 ,应用Carto系统标测可清楚地显示折返途径 ,消融折返所经过的关键峡部可望达到根治目的。

Hybrid FEM-BEM for simulation of electromagnetic response

A finite element method with boundary element method (FEM-BEM) is presented for computing electromagnetic induction. The features of an edge element method including the volume and surface edge element method are investigated in depth. Surface basis functions of edge elements to an arbitrary shape of target are derived according to the geometrical property of basis functions and applied to discretize the surface integral equation for 3-D general targets. The proposed model is presented to compute resonant frequencies and surface current of underground unexplored ordnance (UXO), and then the electromagnetic responses of single target with different frequencies and positions of sensor are simulated and results are validated by experiments.

Calibration Scheme Under Spherical Coordinates for Magnetic Tracker Used in VR System

A calibration scheme under spherical coordinates is described for a magnetic tracker used in VR (virtual reality) system. A look up table containing data of tracked values for certain positions in the working space, spe cified in spherical coordinates, is generated first, which is then used to calibrate the tracking results by a two dimensional interpolation. The scheme can effectively correct the static errors in the magnetic tracking system. The employment of spherical coordinates significantly reduces the calculation complexity in calibration.

CARTO系统——复杂心律失常治疗的好帮手

射频消融治疗心律失常的传统标测方法是通过直接记录多导心内电图，根据局部电位的形态、振幅以及相互之间的时间关系定位。对于心律失常，射频消融具有简单、实用和快速的优点，但对复杂的心律失常则常常勉为其难。近年来，一种新的标测定位技术。三维电磁标测系统已日趋成熟，在许多国家的医疗机构中开始将其广泛应用于临床。

The distribution of deep source rocks in the GS Sag:joint MT-gravity modeling and constrained inversion

The coal-bearing strata of the deep Upper Paleozoic in the GS Sag have high hydrocarbon potential. Because of the absence of seismic data, we use electromagnetic （MT） and gravity data jointly to delineate the distribution of deep targets based on well logging and geological data. First, a preliminary geological model is established by using three-dimensional （3D） MT inversion results. Second, using the formation density and gravity anomalies, the preliminary geological model is modified by interactive inversion of the gravity data. Then, we conduct MT-constrained inversion based on the modified model to obtain an optimal geological model until the deviations at all stations are minimized. Finally, the geological model and a seismic profile in the middle of the sag is analysed. We determine that the deep reflections of the seismic profile correspond to the Upper Paleozoic that reaches thickness up to 800 m. The processing of field data suggests that the joint MT-gravity modeling and constrained inversion can reduce the multiple solutions for single geophysical data and thus improve the recognition of deep formations. The MT-constrained inversion is consistent with the geological features in the seismic section. This suggests that the joint MT and gravity modeling and constrained inversion can be used to delineate deep targets in similar basins.

Fabrication and Characterization of VO_2 Thin Films by Direct Current Facing Targets Magnetron Sputtering and Low Temperature Oxidation

Low valence vanadium oxide(VO2-x) thin films were prepared on SiO2/Si substrates at room temperature by direct current facing targets reactive magnetron sputtering, and then proc- essed through rapid thermal annealing. The effects of the annealing on the structure and phase transition property of VO2 were discussed. X-ray photoelectron spectroscopy, X-ray diffraction tech- nique and Fourier transform infrared spectroscopy were employed to study the phase composition and structure of the thin films. The resistance-temperature property was measured. The results show that VO2 thin film is obtained after annealed at 320 ℃ for 3 h, its phase transition tempera- ture is 56 ℃, and the resistance changes by more than 2 orders. The vanadium oxide thin films are applicable in thermochromic smart windows, and the deposition and annealing process is compatible with micro electromechanical system process.

Fabrication of solenoid-type microinductor with different magnetic core schemes by MEMS technique

Two micromachined solenoid-type inductors with different electroplated core structures, ellipse and rectangle, were fabricated, tested and compared in order to reach optimum designs for integrated induetoes and transformers. In the process of fabrication, UV-LIGA, dry. etching technique, fine polishing and eleetroplating techniques have been adopted to achieve high performance mieminduetor. Experimental results show that both types of the induetors are characterized by high inductance, Q-factor and low electrical resistance. While the inductance of the inductor with rectangular magnetic core is slightly higher than that with elliptical magnetic core, the quality factor of the latter is larger than that of the former.

Electromagnetic Compatibility Technology of Electric Vehicles and Its Development Trend

The electromagnetic compatibility of electric vehicles is not only the important technology issue in researches,development and industrialization of electric vehicles,but also the key research area of ISO.In this paper,both national and international standards of electromagnetic compatibility of electric vehicles are analyzed;it is also suggested that our standards of electromagnetic compatibility of electric vehicles be improved from several aspects such as testing items,test procedures,limit value,etc.The electromagnetic environment of electric vehicles is analyzed in terms of interfering sources,providing the solutions to electromagnetic compatibility and measures of reducing electromagnetic interference.Advanced equipments introduced into Chinese electromagnetic compatibility testing laboratories accelerate the pace of the researches on related technologies and standards;China will develop the standards system which covers from the complete electric vehicle to the key components,promote the technology improvement and industrialization work of Chinese electric vehicles,transform the latest achievements and advanced experiences of Chinese electric vehicles industry to the related standards and contribute the development of international standards.

A novel current vector decomposition controller design for six-phase permanent magnet synchronous motor

The vector control algorithm based on vector space decomposition （VSD） transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a current vector decoupling control algorithm for six-phase permanent magnet synchronous motor （PMSM） is designed. Using the proposed synchronous rotating coordinate transformation matrix, the fundamental and harmonic components in d-q subspace are changed into direct current （DC） component, only using the traditional proportional integral （PI） controller can meet the non-static difference adjustment, and the controller parameter design method is given by employing intemal model principle. In addition, in order to remove the 5th and 7th harmonic components of stator current, the current PI controller parallel with resonant controller is employed in x-y subspace to realize the specific harmonic component compensation. Simulation results verify the effectiveness of current decoupling vector controller.

原地跑频率测定器

原地跑頻率測定器用来檢查运动員在規定时間内原地跑的頻率,和規定时間內前后各阶段中跑的頻率和抬腿高度的变化,借以反映出大(月老)皮质相应于下肢部分的运动分析器的灵活性和工作能力。构造如图由座板(1)、紀紋鼓(2)、記时部分和記跑部分构成。記时部分包括台式間隔时間記录器(3)、电磁标(4)和固定电磁标的支柱(5)等部分。記跑部分包括跑动杠杆(6)、滑輪支柱(7)和記录指針(8)等部件。記时部分和記跑部分安放在座板的左側,記紋故安放在座扳的右侧。跑动杠杆由木料做成,支柱(6a)是-內柱(6б)插在套筒(6B)

Wideband electromagnetic characteristics modeling and analysis of missile targets in ballistic midcourse

The wideband electromagnetic characteristics of missile targets in midcourse are the foundation of midcourse attack-defense confrontation. This paper proposes a novel electromagnetic scattering modeling method for midcourse targets based on a pre- cise scattering center model, in which the nonideal scattering phenomenon, shielding effect and micro-motion are taken into consideration for the first time. Firstly, a precise scattering center model incorporating both the sliding scattering and artist- tropic scattering is established. Then the change rule of the target attitude is generalized, and a checking method of the scatter- ing center shielding effect is proposed for rotationally symmetric targets. Afterwards, a novel dynamic electromagnetic scat- tering model is presented, where the scattering center model updates along with the variation of the target attitude and can characterize the change of the electromagnetic characteristics of midcourse targets exactly. Finally, in light of the established model, the dynamic electromagnetic characteristics within different attitude angle bounds are analyzed by stages, and some useful conclusions are obtained. Experiment results from the measured data in anechoic chamber verify the validity of the proposed modeling method and relevant analysis.

Nonlinear magnetic network models for flux-switching permanent magnet machines

In this paper, firstly, a basic nonlinear magnetic network model considering iron saturations is proposed for a three-phase 12-stator-slot/10-rotor-pole flux-switching permanent magnet(FSPM) machine. This model is built under cylindrical coordinates and enables the open-circuit air-gap flux-density distributions, phase permanent magnet(PM) flux-linkage, and electromotive-force(EMF) to be predicted with acceptable accuracy. However, large discrepancies are found in the predictions of armature inductances. Then, the basic model is modified by taking into account the localized saturation effect. As a result, the electromagnetic performance can be predicted more accurately, especially for the air-gap flux-density distributions. Furthermore, two improved models are proposed by adding bypass-bridge branches in stator network, to enhance the calculating accuracy of both saturated and unsaturated armature inductances. Finally, the predicted results from the four magnetic network models are validated by both 2D finite element analysis(FEA) and experimental measurements on a machine prototype. Overall, comparisons indicate that the model with bypass-bridge branches between stator teeth and back irons exhibits best performances.