Three-dimensional modeling of the anatomy of the heart and great vessels

Summary The anatomic constraints imposed on a total artificial heart (TAH) require specific anatomic studies. A thoracic anatomic study was performed with a scanning device equipped with three-dimensional (3-D) reconstruction software on 15 male patients, between the ages of 41 to 63 years (52 ± 6 years). All were candidates for heart transplantation. The 3-D reconstructions of the cardiovascular structures obtained from surgical anatomy data specific to TAH implantation allowed a volumetric measurement of these structures. A modeling diagram of these structures permitted reproducible quantitative measurements of the 35 geometrical parameters which characterized shape, orientation, and position of these structures within the thorax. Most of the measured parameters were characterized by low variability (coefficient of variation from 10 to 25%).

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Modélisation tridimensionnelle de l'anatomie du cur et des gros vaisseaux

Résumé Les contraintes anatomiques imposées au cur artificiel total (CAT) nécessitent des études anatomiques spécifiques. Une étude anatomique thoracique a été réalisée avec un scanner doté d'un logiciel de reconstruction tridimensionnelle (3-D) chez 15 patients, tous de sexe masculin, agés de 41 à 63 ans (52 ± 6 ans), et candidats à une transplantation cardiaque. Les reconstructions 3-D des structures cardio-vasculaires réalisées selon les données de l'anatomie chirurgicale propre à l'implantation du CAT ont permis la mesure volumétrique de ces structures. Un schéma de modélisation de ces structures a permis des mesures quantitatives reproductibles de 35 paramètres géométriques caractéristiques de la forme, de l'orientation, de la position de ces structures dans le thorax. Les résultats de ces mesures ont pu être exprimés en termes statistiques. La plupart des paramètres mesurés étaient caractérisés par une faible variabilité (coefficients de variations de 10 à 25%).

     

Correlation dimension analysis of the artificial circulation

Artificial circulation has been analyzed by decomposing it into parts. However, the sum of the decomposed parts is not equal to the whole system, especially in nonlinear dynamic systems such as biological systems. To evaluate prosthetic circulation as an entity, not as decomposed parts, nonlinear mathematical analytic techniques, including fractal dimension analyzing theory, were used. Two pneumatically actuated ventricular assist devices were implanted as biventricular bypasses (BVB) in chronic animal experiments using four healthy adult goats. For comparison between natural and prosthetic circulation in the same experimental animals, the BVB-type complete prosthetic circulation model with ventricular fibrillation was adopted. All hemodynamic parameters with natural and prosthetic circulation were recorded under awake conditions and calculated by a personal computer system. By the use of nonlinear mathematical techniques, time-series data of the hemodynamics were embedded into the phase space, and correlation dimension analysis was performed to evaluate the reconstructed attractor. Our results suggest that the correlation dimension of the arterial blood pressure does not linearly increase according to the increase of the embedding dimension, even during artificial circulation, suggesting those are the fractal time series data. Dimensional analysis of the hemodynamics revealed that lower dimensional fractal dynamics were observed during prosthetic circulation. Fractal time series data are suggested to have robustness and error resistance. Thus, our results suggest that the circulatory regulatory system with the artificial heart may have these desirable characteristics. Accepted: July 14, 1995     

心理干预对人工流产术妇女焦虑情绪的影响

目的:探讨综合性心理干预对人工流产术妇女焦虑情绪的影响。方法:选取妊娠6周~10周要求终止妊娠而无禁忌证的第一次接受人工流产术的门诊妇女100例,随机分为干预组50例、对照组50例。干预组进行综合心理干预,包括术前的健康教育、放松训练和术中的音乐辅助放松,对照组常规处理。手术前后测量两组心率,评估焦虑情绪(Zung焦虑自评量表SAS)、疼痛程度,并对人工流产综合征进行评价。结果:干预前干预组与对照组一般资料、血压、心率和SAS评分无明显差别。干预后①干预组术中中重度疼痛发生率(18%)明显低于对照组(44%,χ2=7.9,P<0.01);干预组人工流产综合征发生率(4%)低于对照组(16%,χ2=4.0,P<0.05);②干预前、术前、术中、术后脉搏变化两组间差异无统计学意义;③术后1周SAS评分干预组明显低于对照组(37.3±5.6/43.3±4.9,t=-5.61,P<0.01)。结论:综合性心理干预有助于降低人工流产术妇女的焦虑程度,降低人工流产综合征的发生率,减轻术中疼痛程度,是一种行之有效的干预方法。     

一种基于EEG特征提取的癫痫棘波综合检测判决方法

癫痫特征的自动检测在临床应用上具有重要的意义。本研究综合小波变换、非线性能量算子、特征提取和神经网络等技术，提出了一种癫痫棘波检测系统，充分发挥各技术的优点，在对真实脑电数据的处理中，表现出良好的性能。     

用高分辨G带和人工细菌染色体荧光原位杂交技术分析中国儿童孤独症患者的染色体改变

目的 检测中国儿童孤独症患者的特征性染色体改变。方法 应用高分辨G带和人工细菌染色体(bacterial artificial chromosome，BAC)荧光原位杂交(flourescence in situ hybridization，FISH)分析68例中国儿童孤独症患者的染色体改变。结果 用G带分析观察到有染色体改变的4例患者，分别为1例t(4；6)(q23-24；p21)、1例21p 和2例9号染色体臂间倒位。BAC FISH进一步证实易位病例，而且更精确[t(4；6)(q25-26；p21-1)]；涉及7号、15号、2号染色体的BAC FISH均未观察到文献中报道的染色体改变；而9号染色体的臂间倒位和21p 因无BAC克隆而无法证实。结论 用G带和BAC FISH发现少数中国孤独症患者有染色体改变，但远没有文献中报道的10％～48％那么高。BAC FISH有助于精确地确定染色体易位断裂点。     

肱骨远端的解剖观测与肱骨假体的设计

目的:为临床肱骨远端假体的设计与安放提供相关数据。方法:测量120块(男35对、女25对)成人干燥肱骨远端相关结构,对所测得结果用SPSS软件处理。结果:(1)肱骨远端前倾角和肱骨滑车外旋角,男女分别为(35.78±5.12)°、(36.33±5.06)°和(5.35±1.13)°、(5.55±1.22)°。(2)内上髁至外上髁最大宽度、滑车最内侧缘至小头最外侧缘宽度、肱骨滑车和肱骨小头宽度男女分别为(58.92±4.03)、(55.75±3.85);(45.34±3.15)、(42.18±3.01);(24.82±1.74)、(21.78±1.51)和(17.69±1.23)、(16.39±1.21)mm。(3)肱骨滑车和肱骨小头最大矢径男女分别为(23.35±2.06)、(23.13±2.15)和(19.47±1.38)、(19.13±2.19)mm。男女之间和左右之间各测量数据无显著性差异(P>0.05)。个体间有较大差异。结论:肱骨远端各项目的测量值,可供设计与安放肱骨假体提供解剖参数。     

Blastocoele collapse by micropipetting prior to vitrification gives excellent survival and pregnancy outcomes for human day 5 and 6 expanded blastocysts

BACKGROUND: Manual puncture of the trophectoderm of human blastocysts with a needle before vitrification increases their survival rate, but the embryos take a long time to re-expand. This study examined whether causing human blastocysts to collapse by manual pipetting before vitrification would allow more rapid re-expansion and improve pregnancy rates. METHODS: After embryo transfer in IVF cycles, surplus embryos that developed to the expanded blastocyst stage were placed in cryoprotectant and then artificially shrunk by mechanical pipetting with a fine hand-drawn glass pipette slightly smaller in diameter than the blastocyst. The shrunken embryos were placed in a small volume of vitrification solution and plunged into liquid nitrogen on a cryotop. The blastocysts were thawed by warming and then dilution in 1 mol/l sucrose. RESULTS: Of 49 expanded vitrified blastocysts, 48 (98%) re-expanded within 3 h after warming. Following transfer (48 blastocysts in 28 cycles), 14 women (50%) became clinically pregnant, and the implantation rate was 33% (16/48). Eight healthy babies have been born in six deliveries, and the other eight pregnancies are ongoing. To date, there have been no spontaneous abortions. CONCLUSIONS: The results suggest that artificial shrinkage with pipetting is a simple and effective technique to assist successful cryopreservation of expanded blastocysts by vitrification.     

不同位置植入SMH人工腰椎间盘对小关节应力分布的影响

目的:通过三维有限元方法研究正常椎间盘、SMH人工腰椎间盘前置、中置和后置四组模型中小关节的应力分布情况,探讨不同位置植入SMH人工腰椎间盘对小关节应力分布的影响。方法:建立正常腰椎间盘、人工SMH腰椎间盘前置、中置和后置的三维模型,然后模拟腰椎节段的运动,进行小关节应力分布的比较研究。结果:与正常L4/5椎间盘模型相比,除SMH人工腰椎间盘前置模型前屈时比正常模型小关节应力小外,其余运动时SMH人工腰椎间盘前置、中置和后置模型中小关节的应力均高于正常腰椎间盘组,但后置SMH人工腰椎间盘组则相对较小。结论:SMH人工腰椎间盘后置可以更好地预防小关节的退变;人工椎间盘植入位置的不同对人工腰椎间盘术远期疗效的预测具一定的作用。     

肠腔静脉人工血管C型分流术的远期疗效观察

目的 探讨肠腔静脉C型分流术治疗食管胃底静脉曲张破裂出血的远期疗效。方法 对成阳市中心医院肝胆外科1992年以来施行的36例肠腔静脉C型分流术的临床资料进行总结分析。结果 36例患者术后门静脉压平均下降1．51kPa，胃镜检查食管静脉曲张均有明显减轻或消失。术后再出血率5．6％，肝性脑病发生率8_3％，术后1年、3年、5年及10年的生存率分别为97．2％、93．3％、89．3％及66．7％。结论肠腔静脉C型分流术手术适应证广，操作简单，近、远期疗效满意，适于推广。     

叶轮泵式全人工心脏的结构设计及流体力学特性

目的通过模型样机研制和流体力学特性测试．探索以叶轮式血泵为结构基础的新型可完全植入的全人工心脏。方法全人工心脏模型样机分为左心泵和右心泵2个基本单位。2血泵均采用叶轮泵．共同设置在球形外壳中。2半球形外壳由高分子材料经激光快速成型制成．球形腔内设置固定左右心泵后对合为球形外壳．表面由医用聚氨酯橡胶涂层，直径55mm，总质量150g左右。在体外模拟循环台上对左心泵和右心泵的流体力学特性进行测试．主要观测指标为泵的转速、输出压力、流量、能耗和效率。模拟循环装置由模拟左右心房、血泵、阻力调节器、流量计串联组成，采用30％甘油水溶液作为循环介质。通过调节阻力测定特定泵转速下压力和流量。结果体外模拟测试表明全人工心脏模型样机可满足血液动力学基本要求，左心泵在9000-13000r／min转速条件下可以达到5-7L／min流量和13．3kPa（100mmHg）的压力输出，右心泵在约1／2左心泵转速和4．00kPa（30mmHg）后负荷下达到相似流量．可分别满足体、肺循环的要求。在该工作负荷条件下，2血泵的总效率约为14％。结论轴流泵作为人工心脏的血泵单位．流体力学特性可达到全人工心脏的基本要求．