用激光多普勒血流仪检测门静脉高压兔的胃粘膜血流量

目的研究门静脉高压症胃粘膜微循环血流量的变化。方法22只兔随机分成2组:门静脉高压模型组(PHT组)11只,通过门静脉部分结扎产生门静脉高压症;假手术组(SO组)11只,仅分离门静脉主干而不结扎。4周后用激光多普勒血流仪(Laser Doppler Flowmetry,LDF)检测胃底、胃窦的粘膜血流量,比较两组间的差异。结果 PHT组胃底、胃窦的粘膜血流量分别为(73.44±25.47)BPU.(97.85±15.05)BPU;SO组相应部位的粘膜血流最为(136.38±18.40)BPU,(89.85±20.34)BPU。PHT组胃底粘膜血流量明显低于SO组(P<0.01),而其胃窦的粘膜血流量与SO组相比稍低,但不具有统计学意义(P>0.05)。结论门脉高压时胃粘膜的血流量降低.     

升主动脉缩窄心衰游离心肌细胞骨架三椎构筑特点

目的 研究心衰时心肌细胞及亚细胞结构的形态学改变,材料和方法,制作鼠升主动脉缩窄模型,制备鼠心衰时的游离心肌细胞,用细胞骨架抽提法制备细胞骨架扫描电镜标本,结果：升主动脉缩窄心衰鼠心肌细胞骨架中微管增加,肌原纤维减少,线粒体固定装置破坏,线粒体发生移位,空泡样改变,Ｔ管开口明显增大,结论：慢性心衰时心肌细胞形态及亚细胞结核均已发生明显的形态学改变。     

激光多普勒血流计在全息穴位上的应用

激光多普勒血流计在全息穴位上的应用文／于泉丽激光多普勒血流计（ＬＤＦ）可以测量皮肤和内脏微区血流量（Ｍｉｃｒｏｂｌｏｏｄｆｌｏｗ，ＭＢＦ）［１］，已应用于皮肤、内脏以及穴位上的测量，但在全息穴位上的应用还未曾见有报道。本文根据全息生物学理论，用ＬＤＦ...     

激光多普勒流量计观察单侧输尿管梗阻大鼠双侧肾皮质微循环血流变化

目的:用激光多普勒流量计观察单侧输尿管梗阻大鼠双侧肾皮质微循环血流的变化,探讨梗阻侧肾间质纤维化的发病机制及健侧肾的代偿机制。方法:成年雌性SD大鼠,随机分为假手术组和模型组。假手术组仅将输尿管游离但不结扎离断,模型组行单侧输尿管结扎术。术后第7、14和21天随机选取并处死各组中的6只大鼠,观察双肾病理学改变,并检测双侧肾皮质微循环血流。结果:H-E染色显示假手术组双侧肾各时间点肾单位结构正常,间质无增宽;模型组大鼠梗阻侧肾术后7 d出现早期间质纤维化的病理改变,并随梗阻时间延长逐渐加重;健侧肾小球系膜细胞增生并随代偿时间延长逐渐增多。肾皮质微循环血流,与假手术组比较,模型组大鼠健侧肾皮质微循环血流显著增加,梗阻侧肾皮质微循环灌注量先增加后进行性降低。结论:血液流变学改变、梗阻侧肾皮质微循环血流灌注量进行性减少是肾间质纤维化的发病机制之一;而健侧肾皮质微循环血流灌注量增高,在一定程度上有利于健侧肾的功能代偿。     

慢性心衰对心肌细胞结构和皮肤微循环的影响

目的我们用本研究室自己制作的Ｗｉｓｔａｒ大鼠升主动脉缩窄模型,经检测达到心衰标准后,制备游离心肌细胞,对其超微结构及三维构筑进行了观察。不仅发现了心肌细胞线粒体规律排列的原因在干线粒体有其特有的固定装置,而且复制出线粒体凹的三维构筑特点;证明在心衰时线粒体的形态学改变、移位、核周围聚集以及Ｚ线扭曲等形态学变化;而且还发现有肌原纤维排列紊乱、断裂、缺失和移位等特征。用激光多普勒血流监测仪,检测的结果证明;慢性心衰时皮肤微循环血流速度明显减慢（手术组１．１８±０．４６ｍｍ／ｓｅｃ;对照组１．６４±０．５７ｍｍ／ｓｅｃ）;组织血流量明显减少（手术组１７．４１±７．４４ｍｌ／ｍｉｎ,对照组２４．７４±７．７２ｍｌ／ｍｉｎ）;左心房游离心肌细胞出现以宽度显著增加为主的特点,手术组游离心房肌细胞宽度为 ４３．９３±１８．４２μｍ,对照组的则为２８．４４±７．６７１μｍ,而心房肌细胞长度的增加相对较小,手术组为１１１．７８μ３０． １０１μｍ,而对照组则为９４．５３±１６．４０μｍ。同时作者对慢性后负荷心衰模型制作,心衰的确定,心衰时不同部位心肌细胞的改变进行了详细的描述。     

高功率多普勒血流探测仪结合血流成像仪观察氯吡格雷对高血压大鼠微循环的影响

目的:观察抗血小板药物氯吡格雷对高血压大鼠微循环的影响。方法:SPF级雄性13周龄自发性高血压大鼠(SHR),随机分为溶剂对照组和氯吡格雷组,每组5只,分别灌胃1ml 0.5%羧甲基纤维素钠(CMC-Na)和氯吡格雷溶液(10mg/kg),每日一次。连续四周后,用高功率激光多普勒血流探测仪(LDF)检测大鼠脑皮质、耳廓及趾血流量、血细胞聚集度和血流速度,用血流成像仪(LDPI)观察脑血流分布状态。统计学分析检测指标的组间差异。结果:除血细胞聚集度和脑皮质血流速度外,氯吡格雷组大鼠上述LDF检测指标值均高于溶剂对照组(P0.05或P0.01),LDPI检测脑皮质血流分布曲线整体右移,脑皮质高血流量(800-1500PU)面积百分比较溶剂对照组明显增加(P0.01)。结论:氯吡格雷可明显改善SHR微循环障碍。     

高血压微循环与体循环动力学临床研究系列——Ⅱ.高血压病人皮肤微循环血流阻力的临床研究

高血压病人30例,正常血压对照30例,采用Laser Doppler血流计测定手指皮肤血流量,间接测定甲襞毛细血管压,并计算皮肤血流阻力,以袖带法测量肱动脉、桡动脉和指动脉血压,计算出平均血压和毛细血管前压降。结果显示:高血压组皮肤微循环中的血流阻力和毛细血管压升高(26.77±14.53对17.74±9.28mmHg/V,P<0.01;68.68±19.42对43.11±10.30mmHg,P<0.01),而皮肤血流改变无显著性差异(2.56±1.01对2.43±0.92,P>0.05);高血压组毛细血管压升高与其上游压降呈负相关关系(r=-0.78,P<0.01),提示皮肤毛细血管压和血流阻力是受其上游“阻力血管”所控制。用血管扩张剂治疗后的病人,血压明显下降而皮肤血流阻力仍处于升高状态。从而提示皮肤血流阻力的“结构成份”增加并借此作为评价“结构阻力”可逆性的客观指标。     

用于皮肤血流成像的激光多普勒扫描仪

本文介绍了一种利用激光照射皮肤表面,收集其具有多普勒频移的散射光来检测血细胞运动,形成皮下毛细血管血流图象的仪器。典型的毛细血管的血细胞流速为1mm/s的量级上,产生的频移为3KHz,较深的血管散射出的多普勒频移为10KHz。由于光在皮肤组织上随机散射,所以多普勒频移和血细胞流速不直接相关。绝对校准多普勒流量仪是不可能的。一般是利用多普勒光谱与皮肤中血流参数的某些相关变量来建立反映出组织中血细胞一般运动的经验公式,而不是真实的流速的测量。本仪器使用2mv的氦氖激光安放在四个光     

三种激光多普勒血流仪的比较研究

激光多普勒血流仪(Laser Doppler Flowmeter)是微循环研究的常用工具。用它测定某微区微循环血液灌流量的原理,主要是根据激光多普勒频移。由氦氖激光器发出的激光,经光导纤维送到被测部位,部分激光被组织吸收,另一部分被散射。其中从静止结构(血管壁,它与血管中流动的红细胞比相对静止)散射回来的激光与原入射光频率相同,而被组织中运动着的结构(微血管中流动     

Lyapunov Exponents of Laser Doppler Flowmetry Signals in Healthy and Type 1 Diabetic Subjects

The skin of diabetic subjects presents abnormalities in capillary blood flow and its regulation, often leading to the generation of plantar ulcers. In order to gain insight into this pathology for type 1 diabetic patients, Lyapunov exponents (LEs) of signals reflecting microvascular perfusion—laser Doppler flowmetry (LDF) signals—are calculated. The algorithm to compute LEs is first validated on simulated data and LDF surrogates. Then, LDF signals recorded at rest and during the application of local and progressive pressure of 11.1 Pa/s are processed. The exponents appear in pairs and are different for healthy and type 1 diabetic subjects at rest; P = 0.0556 for the 7th, 8th, and 9th LEs. Furthermore, progressive pressure has also a distinct effect on LEs. The difference is more pronounced for diabetic patients, for whom P = 0.0625 for the four LEs of highest absolute value. Because these differences arise from abnormalities in microvascular blood flow, they may help to explain the high prevalence of type 1 diabetic patients developing foot ulcers.     

Laser Doppler perfusion monitoring and imaging: novel approaches

Laser Doppler flowmetry (LDF) is a non invasive method enabling the monitoring of microvascular blood flow, a very important marker of tissue health. This article gives an overview on the concept of LDF for microvascular perfusion monitoring and imaging. It first describes the theoretical background of the technique. Then, the benefits of LDF signal processing are shown through clinical examples: use of time-frequency representations and wavelets. Afterwards, the paper introduces novel approaches of velocity components. For that purpose, a work providing the determination of the velocities relative contribution in physiologically relevant units (mm/s) is presented. Imaging perfusion is also reviewed through methods based on laser speckle. The most prominent disadvantage of the latter devices being the time needed to produce a perfusion image, solutions are proposed in the last part of the paper.     

不同年龄和部位女性皮肤微循环变化

目的观察不同部位皮肤血管结构和形态差异,研究年龄对真皮微循环功能的影响.方法采用活体电视毛细血管镜(Intravital Video-capillaroscopy)和激光多谱勒血流仪(laser Doppler flowrnetry)对50名年龄在20～74岁,光皮肤类型为Ⅱ～Ⅲ型白人女性志愿者的前额、眼角、前臂内侧和手背血管作初步观察.并用计算机图象处理技术,对前臂和手背活体真皮血管密度作定量分析.结果真皮乳头毛细血管襻在活体电视毛细血管镜下为点状或逗点状;乳头下的血管丛表现为线条状或网状;年轻人皮肤血管排列整齐,年龄较大者血管扩张增粗、扭曲,排列不规则.年龄与襻状血管数、襻状血管面积显著负相关;与襻状血管间距、平行血管总长正相关;真皮血流量面部高于肢端;随年龄的增加真皮血流有逐渐增加趋势.结论年龄影响真皮微循环的形态和功能.两种无创性检测技术联合应用能动态研究活体真皮血管的形态和结构,在皮肤血管性疾病的诊断和治疗方面有较高的应用前景.     

高血压微循环与体循环动力学临床研究系列——Ⅳ.利用激光多普勒血流计测评高血压患者反应性充血

在本实验中,我们利用激光多普勒血流计测量了25例高血压病人的手指皮肤阻断后反应性充血(PORH)及降压治疗对其影响,结果显示高血压病人(PORH)过程较正常人显著延长(P<0.05),而各流量参数在两组间则无显著差异,同时,我们发现,手腕及手指根部阻断时对于正常人,充血峰值的静息值百分比(PF％)和静息值(RF)之间存在着良好的相关性,而此种情况不存在于高血压病人,经降压治疗后,病人组反应性充血较前加快(P<0.05),此外,我们评价了年龄对正常人PORH的影响,发现较老年组PORH慢于较青年组(P<0.05)。     

2型糖尿病患者足背皮肤微血流变化及其相关危险因素分析

目的:探讨病程≤5年的2型糖尿病患者是否已经存在皮肤微血流的变化,分析影响2型糖尿病患者皮肤微血流的相关因素。方法:应用激光多普勒血流仪(LDF)对24例病程≤5年的2型糖尿病患者(糖尿病组)和25例非糖尿病对照者(对照组)进行足背皮肤微血流测定。微血流的测定应用阻断后反应性充血(PORH)的方法,通过LDF记录皮肤微血流阻断前基值(PORHrest)、袖带加压阻断后最小值(PORHmin)和减压后反应性充血的微血流峰值(PORHpeak),其它观察指标还有微血流从开始减压到升至峰值的时间(Tp)、PORHmax(=PORHpeak-PORHrest)和PORHmax/Tp[=(PORHpeak-PORHrest)/Tp]。结果:与对照组相比,糖尿病组的PORHrest、PORHpeak、PORHmax均明显下降,而Tp和PORHmax/Tp明显增加。多元逐步回归分析显示,影响PORHrest的因素是空腹血糖(FBG)和舒张压(DBP);影响PORHpeak的因素是DBP;影响PORHmax的因素是DBP和FBG。结论:病程≤5年的2型糖尿病患者已存在下肢皮肤微血流改变,高血压、高血糖是导致其微血管病变的主要危险因素。     

激光多普勒血流量图像仪在微循环基础与临床研究中的初步应用

利用激光多普勒效应非接触式扫描成像的原理，我们用激光多普勒血流量图像仪（ＬＤＩ）测量失血和再灌注期间大鼠小肠组织灌流量的变化；比较人体皮肤鲜红斑痣在激光治疗前后血流量的变化以及心脏直视手术中心脏在不同状态下心肌灌流量的改变。实验结果表明ＬＤＩ能够客观反映在不同的功能状态下组织血液灌流量的变比。提示：测量一区域组织表面血流量可反映组织微循环功能，在临床检查中具有重要意义；而作为自动化测量系统，激光多普勒血流量图像仪的性能优于激光多普勒血流量计。     

激光多普勒成像技术对体表不同部位微血流图象的初步观察

目的了解激光多普勒血流成像系统这一新的医学影象技术在人体不同部位测量中的实用价值.方法使用激光多普勒血流成像仪,对人体不同部位的微循环血流阻断、加温后的手部微循环图象予以观察,分析微循环血流图的特点及变化.结果(1)前臂内外侧面和手背、足背和腕部、额部、鼻梁和髌部的血流量分布较少,手掌的大小鱼际部位和指尖、脚趾和趾尖、口唇、颊部等部位的血流分布较多.(2)30 min内前臂、手掌和手背血流的自然波动较小.(3)上肢加压阻断后,手掌部位的血流明显减少.松解加压后,血流恢复.(4)上肢肘部给予加温,手掌部位的血流明显增加.停止加温后,血流逐渐恢复.结论激光多普勒血流成像仪能够以大范围成像方式显示体表不同部位的微循环图象和外界影响血流改变因素导致的血流变化过程.     

Discrimination of capillary and arterio-venular blood flow in skin by laser Doppler flowmetry

The scattering and absorption of light by tissue and blood is wavelength dependent; the tissue penetration of green light (λ=543·5nm) is about 60 per cent of that of red light (λ=632·8 nm) but the absorption of green light by blood is about 20 times greater than for red light. The effect of this difference has been studied by observing the responses of skin blood flow to heat and weal, measured by laser Doppler flowmetry at the two wavelengths. By using time autocorrelation function analysis (ACF) of the scattered light measured, low and high frequency components have been associated with capillary and larger vessel flow, respectively. The comparison of ACF from scattered green and red light has shown that measurements cannot be interpreted by only considering light penetration depth through a homogeneous tissue. Light absorption and multiple scattering by blood at the individual microvessel level, blood rheology and vessel morphology are parameters which are considered for greater attention.     

Functional evidence for the differential control of superficial and deep blood vessels by sympathetic vasoconstrictor and primary afferent vasodilator fibres in rat hairless skin

We quantitatively investigated sympathetic vasoconstriction and antidromic vasodilation mediated by small-diameter primary afferents on the plantar hairless skin of the hindpaws in Wistar rats using laser Doppler (LD) flowmetry and an infrared thermometer. Sympathetic vasoconstriction was elicited by electrical stimulation of the centrally cut ipsilateral lumbar sympathetic trunk (LST) with 50-s trains at 0.1–20 Hz. Antidromic vasodilation was evoked by electrical stimulation of the dorsal root (DR) L5 with 20-s or 50-s trains at 1–4 Hz. Cutting the LST resulted in increases in skin temperature (SKT) by 6.1±1.0° C (mean±SEM) and in LD flow by 128±20%. Stimulation of the LST resulted in a graded decrease in LD flow and SKT that was most pronounced between 0 and 0.1 Hz. However, DR stimulation evoked a large increase in LD flow but only little change in SKT in rats with sectioned LST. When the DR was stimulated either in animals with intact LST or during continuous stimulation of vasoconstrictor fibres in the sectioned LST, i.e. while baseline temperature was relatively low (26.3±1.1° C), DR stimulation still resulted in large increases in LD flow, but only minor changes in SKT. These results suggest that blood flow through both deep and superficial layers of rat hairless skin is regulated by activity in sympathetic postganglionic vasoconstrictor fibres, whereas small-diameter primary afferent fibres appear to influence predominantly the blood flow through superficial layers of rat plantar skin. Received: 22 April 1997/Accepted: 11 July 1997