Single-fibre laser Doppler flowmetry

A laser Doppler flowmeter with one optical fibre guiding light to and from the tissue under study has been developed. The outer diameter of the probe equals the optical fibre diameter (0·5 mm). The small size makes it useful for studying the deep tissue perfusion in organs. Differential-channel operation was compared with the single-channel operation and the benefit of this technique was evaluated theoretically as well as in a fluid model resembling tissue perfusion. The signal-to-noise improvement ratio was calculated and found to be related to the number of coherence areas detected and to the broadband noise of the laser. In vivo experiments in the gastrocnemius muscle of the pig were performed to compare the results from the single-fibre technique with those of the electromagnetic flowmeter. Linear regression analysis of femoral blood flow data obtained with the electromagnetic flowmeter and local muscle blood flow measured with the single-fibre technique showed a correlation coefficient of 0·88 (n=36, p<0·001).     

Myocardial tissue motion influence on laser Doppler perfusion monitoring using tissue Doppler imaging

Tissue motion of the beating heart generates large movement artifacts in the laser Doppler perfusion monitoring (LDPM) signal. The aim of the study was to use tissue Doppler imaging (TDI) to localise intervals during the cardiac cycle where the influence of movement artifacts on the LDPM signal is minimum. TDI velocities and LDPM signals were investigated on three calves, for normal heartbeat and during occlusion of the left anterior descending coronary artery. Intervals of low tissue velocity (TDI_int<1 cm s⁻¹) during the cardiac cycle were identified. During occlusion, these intervals were compared with low LDPM signal intervals (LDPM_int<50% compared with baseline). Low-velocity intervals were found in late systole (normal and occlusion) and late diastole (normal). Systolic intervals were longer and less sensitive to heart rate variation compared with diastolic ones. The overlap between LDPM_int and TDI_int in relation to TDI_int length was 84±27% (n=14). The LDPM signal was significantly (p<0.001, n=14) lower during occlusion if calculated during minimum tissue motion inside TDI_int), compared with averaging over the entire cardiac cycle without taking tissue motion into consideration. In conclusion, movement artifacts are reduced if the LDPM signal is correlated to the ECG and investigated during minimum wall motion. The optimum interval depends on the application; late systole and late diastole can be used.     

一种新型多普勒血流仪的研制

目的 研制一种具有数据采集、存储、传输、显示及声音辅助诊断功能,可以面向社区和家庭应用的便携式多普勒血流仪.方法 基于多普勒测量血流原理,以STM32微处理器为核心,采用定向型正交相位解调法获取多普勒频移信号,通过电源模块、数据采集模块、USB模块、按键模块、数据存储模块、音频处理模块、液晶显示模块、网络收发模块等外围电路,结合PC构成一个完整的血流检测系统.结果 该血流仪能够实现对患者血流数据的采集、处理、存储、传输,可实时显示脉率、诊听血流声音及输出双向血流频移波形和血流速度波形,可用于糖尿病足的诊断.结论 该血流仪使用方便,通过血流声音、血流速度波形、频移波形和脉率等反映血流特征的信息,进行糖尿病足等与血流相关慢性病的早期检测.     

Assessment of coronary flow reserve with transthoracic Doppler echocardiography: comparison with intracoronary Doppler method

To evaluate the feasibility and usefulness of transthoracic Doppler echocardiography (TTDE) as a non-invasive method in recording distal anterior descending (LAD) coronary flow velocity, we compared coronary flow reserve (CFR) measured by TTDE with measurements by intracoronary Doppler wire (ICDW). Twenty-one patients without LAD stenosis were studied. ICDW performed at baseline and after intracoronary injection of 18 microg adenosine. TTDE was performed at baseline and after intravenous adenosine (140 microg/kgmin for 2 min). Adequate Doppler recordings of coronary flow velocities during systole were obtained in 14 of 21 study patients (67%) and during diastole in 17 (81%) patients. Baseline and hyperemic peak diastolic flow velocities measured by TTDE were significantly smaller than those obtained by ICDW (p<0.05). However, diminishing trends of diastolic and systolic velocity ratio after hyperemia were similarly observed in both methods. CFR obtained by TTDE (3.0+/-0.5), was higher than the value calculated by ICDW (2.5+/-0.4). There were significant correlations between the values obtained by the two methods (r=0.72, p<0.01). It is concluded that TTDE is a feasible method in measuring coronary flow velocity and appears to be a promising non-invasive method in evaluating CFR.     

彩色多普勒血流显像与彩色多普勒能量图在恶性滋养细胞肿瘤的应用

目的探讨彩色多普勒血流显像(CDFI)及彩色多普勒能量图(CDE)在恶性滋养细胞肿瘤(GTD)早期诊断及化疗监测中的应用价值. 方法对20例GTD进行CDFI、CDE检测,观察其血流情况及用PD检测病变区血流速度,测算RI值. 结果 CDFI显示病变区血流异常丰富,CDE显示更丰富的血流信号.PD检测出低阻血流,RI=0.41±0.07,化疗前后相比CDFI、CDE和PD改变明显,RI值差异有非常显著性意义(p<0.01). 结论 CDFI、C DE对恶性滋养细胞肿瘤诊断及观察疗效均有十分重要的价值.     

Computer processing of cardiac Doppler signals

A computer processing method has been developed for the extraction of parameters from cardiac Doppler signals. This method is based on the nature of these signals and on the method of their measurement. The parameters are estimated after background subtraction from adequately smoothed spectrograms. The improvement gained by this method of parameter extraction from smoothed spectrograms, rather than from raw spectrograms, is demonstrated. The method is used successfully in a reference value study of cardiac Doppler signals.     

彩色多普勒超声对肝移植后胆道并发症的诊断价值

背景：肝移植后胆道并发症是引起移植后移植肝失功的重要原因,彩色多普勒超声是目前公认的肝移植后患者随访首选简便的检查方法,可以为临床上对肝移植后并发症的诊治提供较可靠的证据。 目的：探讨彩色多普勒超声在肝移植后胆道并发症诊断中的应用价值。 方法：回顾性分析126例肝移植后常规超声检查时胆道并发症的发生情况及彩色多普勒超声检查结果。以磁共振胆胰管成像或超声造影或穿刺引流或临床诊断性治疗等诊断胆道并发症为标准,使用彩色多普勒超声观察肝移植后胆总管及肝内胆管是否有胆漏、狭窄、扩张、胆泥及结石形成。 结果与结论：126例中超声诊断胆道并发症的共33例,其中胆漏4例(3.2%),胆道狭窄11例(8.7%),胆道结石或(和)胆泥18例(14.3%)。提示彩色多普勒超声对肝移植后胆道并发症的诊断具有重要价值,可为临床的诊治提供依据。     

肝移植后彩色多普勒超声的应用

背景：肝移植后监测移植肝脏并发症的发生情况,对肝移植的成功率及延长患者生存时间具有十分重要的意义。 目的：评价彩色多普勒超声对肝移植后并发症的监测效果。 方法：由作者采用电子检索的方式,在万方数据库(http://www.wanfangdata.com.cn/)及Medline数据库(http://www.ncbi.nlm.nih.gov/pubmed/)中以“彩色多普勒超声,肝移植,移植后并发症”为关键词,检索1990-01/2010-12有关彩色多普勒超声对肝移植后并发症监测效果的文章,共查到相关文献60余篇。经阅读标题、摘要、全文,排除内容重复、普通综述、Meta分析类文章后,筛选纳入22篇文献进行评价。 结果与结论：彩色多普勒超声检查具有无创、简便、直观、定位准确及可动态观察等优点,在肝移植后不仅能有效地检测肝脏大小、移植肝形态,而且可以从内部回声及血流动力学方面为肝移植后并发症的早期诊断提供线索,对临床及早治疗、保证肝移植成功具有重要的作用,是肝移植后监测的首选影像学检查方法。     

彩色多普勒对移植肝脏的血流动力学监测

采用彩色多普勒超声对移植肝血流动力学进行监测，了解肝移植前后肝脏血流动力学变化。观察与推测血管吻合口的通畅程度，寻找与排除并发症的存在，进而判断移植肝成活度及预后，就本院近期6例同种原位肝移植术后的移植肝血流进行检测，观察动、静脉吻合口的通畅情况及门静脉与肝动脉血流动力学改善程序，6例移植肝脏周围未见液性及实性异常回声，肝内实质及管道回声与血流方向，速度正常，在24个吻合口中，5例门静脉吻合口通过，1例门静脉吻合口稍窄，局部血流速度稍快，12个腔静脉吻合口中11个吻合口通畅，1个下腔静脉肝下段吻合口稍窄，6个肝动脉吻合口以远的肝动脉血流速度，阻力指数正常，肝移植是解决门脉高压的根本办法，彩色多普勒超声是移植肝血流动力学变化无创检测最佳手段。     

肝移植后胆道并发症的超声诊断价值

背景：肝移植后胆道并发症可引起移植后肝失功,超声是移植肝胆道并发症的重要检查手段之一。目的：探讨超声对肝移植后胆道并发症的诊断价值。方法：纳入92例肝移植患者,男81例,女11例,年龄21-67岁;其中同种异体原位肝移植90例,活体部分肝移植2例;胆道重建方式均为胆管-胆管端端吻合。回顾性分析肝移植后常规检查及彩色多普勒超声检查结果,着重分析患者有无胆漏、胆道狭窄、胆泥或胆石形成,部分患者于超声引导下穿刺引流。结果与结论：92例患者中超声诊断肝移植后胆道并发症14例：胆漏5例;胆道狭窄4例,其中吻合口狭窄2例,非吻合口狭窄2例;4例胆泥形成;1例胆管结石。提示肝移植胆道并发症患者有特征性超声表现,超声对肝移植后胆道并发症的诊断有重要价值。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

超声造影在原位肝移植术后血管并发症早期发现中的应用

目的 评价超声造影在原位肝移植术后血管并发症早期发现中的意义.方法 对肝移植术后存活的89例患者进行常规超声检查追踪,对发现血流参数异常的患者行超声造影检查和CT血管造影检查,分析常规超声、超声造影和CT血管造影检查之间的一致性.结果 常规超声检查发现血流参数异常27例,经超声造影诊断为术后血管并发症12例,并与CT血管造影检查结果 相一致.结论 通过超声造影追踪可以早期发现肝移植术后血管并发症,让术后血管并发症患者得以及时治疗,明显提高手术的成功率及患者的成活时间.     

彩色多普勒超声评价移植肾的并发症

背景：彩色多普勒超声检查可较敏感地反映移植肾形态结构及血流动力学的改变,随时观察移植肾的成活情况。 目的：评价彩色多普勒超声在移植肾并发症中的应用效果。 方法：由第一作者以“彩色多普勒超声,移植肾,术后并发症”为关键词在万方数据库检索1999-01/2010-12有关彩色多普勒超声对移植肾中并发症应用效果的文章,筛选纳入20篇文献进行评价。 结果与结论：彩色多普勒超声具有简便、迅速、无创、可重复性等优点,已成为肾移植后临床观察治疗效果的首选监测手段。它能客观、动态显示移植肾形态结构及其内部的血流分布,血流频谱形态、流速、舒张期血流方向和血流指数变化,及时发现移植肾各种并发症,为临床提供有价值的诊断信息,避免移植肾功能丧失。     

超声造影在增强原位肝移植后肝脏血管显像中的作用

目的　评价超声造影与彩色多普勒在观察原位肝移植后供肝血管血供情况中的作用。方法　分析了原位肝移植后的 4 7例患者 ,在注射利声显造影剂前后 ,用彩色多普勒分别观察肝脏血管的血供情况 ,并按供肝血管的血供情况进行评分等级分析 ,评分根据彩色多普勒检测血流信号的多少分 0～ 4级。结果　门静脉的血供情况在使用利声显造影前后无明显变化。肝动脉在使用利声显造影剂前 ,4 7例患者中彩色多普勒只检测到 39例患者的血流信号。应用造影剂后 ,4 6例患者的肝动脉均检测到血流信号 ;另 1例患者的肝动脉未检测到血流信号 ,后经血管造影确诊为…     

彩色多普勒超声在诊断乳腺肿块中的应用

目的 评价彩色多普勒超声在乳腺肿块中的诊断价值.方法 应用彩色多普勒,对86例乳腺良性肿块及恶性肿瘤患者分别进行彩色多普勒检查,经手术、病理证实的乳腺肿块的超声诊断对照分析.结果 彩色多普勒超声检查对乳腺肿瘤的早期检出具有重要价值,能准确快速诊断乳腺肿块性质、大小、内部结构,能动态、清晰地显示病灶周边及内部血管分布情况及血流频谱的相关参数.结论 彩色多普勒超声检查可为乳腺肿块的性质提供可靠诊断依据.     

彩色多普勒超声在诊断乳腺肿块中的应用

目的评价彩色多普勒超声在乳腺肿块中的诊断价值。方法应用彩色多普勒,对86例乳腺良性肿块及恶性肿瘤患者分别进行彩色多普勒检查,经手术、病理证实的乳腺肿块的超声诊断对照分析。结果彩色多普勒超声检查对乳腺肿瘤的早期检出具有重要价值。能准确快速诊断乳腺肿块性质、大小、内部结构,能动态、清晰地显示病灶周边及内部血管分布情况反血流频谱的相关参数。结论彩色多瞢勒起声检查可为乳腺肿块的性质提供可靠诊断依据。     

彩色多普勒超声诊断下肢静脉血栓及其形成因素的分析

目的 探讨下肢静脉血栓彩色多普勒超声影像学的特点,评价其临床诊断价值,并对其形成因素进行分析,为临床早期发现下肢静脉血栓及早期治疗提供依据.方法 对32例下肢静脉血栓患者进行彩色多普勒超声检查,观察其血栓的回声特点、血栓范围、静脉管壁、血管内径及其血流情况.结果 32例患者中,彩色多普勒超声诊断急性下肢静脉血栓17例,亚急性血栓12例,慢性血栓3例,各期的超声影像学特点均有其特异性;同时在患者中以下肢外伤性骨折居多.结论 彩色多普勒超声检查是下肢静脉血栓无创检查的首选方法,它不仅可以对下肢静脉血栓程度及范围作出肯定的诊断,同时可以动态观察其演变情况,在临床诊断下肢静脉血栓中具有其他影像学不可替代的优势.     

多普勒效应的模拟设计

利用VB编程技巧，形象展示多普勒效应的物理机理，便于学生理解和掌握。