Improved thermistor transducer and its application for detection of latent heart failure

A thermistor transducer is described which has been designed for the detection of the carotid pulse. Dimensioning parameters are presented. The transducer is characterised by a superior signal-to-noise ratio which enables double differentiation and processing of the steep upstroke of the second derivative. For marking the termination of the ejection period, a newer criterion is defined, featuring advantages for automatic data acquisition. The almost undistorted reproduction of the initial phase of isotonic contraction (s.e.t. interval) is realised by suitable dimensioning of the transducer. Application of the transducer for measuring a modified pre-ejection interval p.e.p.^* and the definition of the so-called pre-ejection index p.i. is given. The first clinical results demonstrate the possibility for the early detection of latent heart failure and revealing the effectiveness of glycoside administration.     

System for simultaneously monitoring heart and breathing rate in mice using a piezoelectric transducer

We propose a novel system for simultaneously monitoring the heart rate (HR) and breathing rate (BR) of anesthetized mice using a piezoelectric transducer (PZT) placed under the body. It is known that a PZT, which transforms mechanical vibrations into electrical signals, can detect heart sounds and breathing movements. However, no PZT system has been reported for simultaneous and continuous monitoring of HR and BR, possibly due to difficulties in eliminating noises and errors caused by the amplitude fluctuation of heart sounds and breathing movements. These difficulties were overcome by custom-designed analogue circuitry and a microprocessor program, resulting in detection of HR and BR with a high reliability compared to the values obtained from ECG and a conventional airflow sensor. We believe that this practical and easy-to-use system can be applied to a wide variety of basic and clinical research fields.     

Recording fetal breathing movements with a passive transducer based on an inductive principle

A new transducer has been developed, based on an inductive principle, for recording fetal movements and sounds. The compliance of this transducer, the INductive PHOno-sensor (INPHO), can be matched to that of the maternal abdomen to provide an optimal transfer of displacement between maternal abdomen and transducer. In this manner it is possible to detect fetal breathing movements by digital filtering of the INPHO signal in a frequency band between 0·5 and 2·0 Hz. Singular breathing movements can be detected and this was verified by real time ultrasound imaging. The INPHO transducer shows a flat (±1·5 dB) frequency response between 0·2 and 200 Hz. The signal-to-noise ratio of the transducer system is better than 95 dB, and enables very weak movements and sounds to be detected. Spectral analysis of the processed signal shows that modulation of fetal breathing by maternal breathing takes place. The measuring setup allows for the quantitative assessment of fetal respiratory sinus arrythymia.     

An ultrasensitive transducer for measurement of isometric contractile force from single heart cells

A novel ultrasensitive force transducer suitable for measuring isometric forces generated by single spindleshaped muscle cells is described. The transducer components are mechanically and electrically simple, consisting of a low power He–Ne laser, a pair of step index, glass optic fibers, and a photodiode detector circuit. To test the operation of the transducer, enzymatically isolated frog ventricular heart cells were used, having peak contractile forces on the order of 100 nN. The transducer presents a number of advantages over existing designs and has a resolution better than 2 nN. As such, it is suitable for excitation-contraction studies in single muscle cells.     

Laparoscopy-assisted intrapelvic sonography with a high-frequency, real-time miniature transducer for assessment of the Fallopian tube: a preliminary report

Our purpose was to visualize normal and abnormal Fallopian tubes using laparoscopy-assisted intrapelvic sonography with a specially developed 20 MHz flexible catheter-based high-resolution, real-time miniature (2.4 mm outer diameter) ultrasound transducer in infertile women. A total of 21 women (20 infertile, one with unilateral hydrosalpinx, and one tubal pregnancy) were studied with pelvic saline effusion under laparoscopy. Fimbriae were clearly depicted with a cockscomb-like form in 95% of patients. All ampullae were visualized, and mucosal layers were clearly distinguished from muscle layers in 70% of patients. Scanty intratubal effusion was noted in 50% of patients, and tubal spastic findings were found in 10% of patients. In all, 60% of isthmuses were detected, and mucosal layers were distinguished from muscle layers in 30%. In the subject with hydrosalpinx, the tubal wall was thinner, and it was not possible to distinguish between muscle and mucosal layers. In the subject with a tubal pregnancy, the amniotic membrane and decidua were depicted more clearly than by transvaginal sonography. In conclusion, laparoscopy-assisted intrapelvic sonography with a high-frequency, real-time miniature transducer may be useful in the assessment of tubal texture and function in tubal disorders, possibly in infertility practice.     

高强度聚焦超声换能器声场的数值仿真与实验测量

目的 高强度聚焦超声(HIFU)肿瘤治疗过程中,HIFU换能器形成的声场分布是决定其治疗效果的关键因素之一,为了提高HIFU肿瘤治疗的安全性和可靠性,需要对HIFU换能器形成的声场进行预测.方法 采用时域有限差分(FDTD)法数值仿真水体内形成的声压分布与实验测量结果对比的研究方法,分析讨论了HIFU换能器在不同激励功...     

A piconewton force transducer and its application to measurement of the bending stiffness of phospholipid membranes

The bending stiffness of a phospholipid bilayer (kc) was measured by forming thin bilayer cylinders (tethers) from giant phospholipid vesicles. Based on the balance of forces, the tether force was expeeted to be proportional to the square root of the membrane tension, with a constant of proportionality containingk>c. The membrane tension was controlled via the aspiration pressure in a micropipette used to hold the vesicle. The force on the tether was generated by an electromagnet acting on a paramagnetic bead attached to the vesicle surface. The magnitude of the force was determined from measurements on the magnet current which was adjusted to maintain the position of the bead. Measurements were performed on vesicles composed of stearoyl-oleoyl-phosphatidylcholine plus 5% (by mole) biotinylated phosphatidylethanolamine to mediate adhesion to streptavidin-coated beads. From each vesicle, tethers were formed repeatedly at different values of the membrane tension. The expected relationship between membrane tension and tether force was observed. The mean value ofkc for 10 different vesicles was 1.17×10⁻¹⁹ J (SD=0.08×10⁻¹⁹ J). The precision of these data demonstrates the reliability of this approach, which avoids uncertainties of interpretation and measurement that may be associated with other methods for determiningkc.     

Continuous measurement of renal intratubular pressures with a combined pressure transducer microperfusion system

Summary A method has been developed which permits continuous recording of intratubular pressures and simultaneous infusion of test solution at rates of 0–50 nl/min through a single microcapillary. Design and operation of the system is described which consists of an ultraminiature pressure transducer, a micro-perfusion pump and the probing microcapillary. Sealing of the latter was achieved by a screw collar which permits rapid replacement of capillaries without deleterious pressure spikes. At optimal supply voltage the recorded signal was independent of input voltage changes (up to ± 100 mV) and directly proportional to a) pressure applied to the microcapillary tip and b) flow rate through the capillary. — As example the pressure increments following local infusion into the proximal convolution of indigocarmine stained saline or reabsorption inhibitors at a rate of 10 nl/min was measured. During the infusion of 10% mannitol intratubular pressure rose to a plateau and remained above control levels. Application of potassium cyanide (1.5×10^–10 M/min) resulted in a gradual pressure increase starting at the onset of the intratubular perfusion. A qualitative similar rise was observed during administration of furosemide (2.2×10^–11 M/min), however the effect exhibited a time delay of several minutes.

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Abbreviations P Pressure on pressure sensitive diaphragm (gauge pressure) in cm H₂O - P _tub Intratubular pressure - P _tub Rise of intratubular pressure, when perfusion is turned on - P _x Pressure due to resistance of capillary tip; - Perfusion rate (nl/ml) - R Flow resistance of capillary tip, measured either in the aqueous phase on the kidney (R _surface) or in the tubular lumen (R _lumen) - U (P=O) Zero pressure output voltage - f.s. Full scale Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

胎儿左心室壁血管与心腔交通的研究

目的：从发生学角度探讨心肌血管重建术的供血机理。方法：本文采用不同胎龄的人胎心１３个，用墨汁灌注血管、组织切片染色法，观测左心室壁与心腔的血管交通状况。结果：显示人类胚胎早期的心脏，心室壁结构类似海绵状，心腔与心壁间存在着许多窦状通道。这类管道包括肉柱间隙、心肌窦样管等，其排列、配布及在心室壁的分布范围随着胎儿生长、结构重建而不断变化。其胚胎发育过程重复了种系发生的各个阶段。结论：提示激光心肌血管重建术从心腔直接供血，与人胚早期者相类似。     

Saline infusion contrast intrauterine sonographic assessment of the endometrium with high-frequency, real-time miniature transducer in normal menstrual cycle: a preliminary report.

Normal endometrial texture was visualized using saline infusion contrast intrauterine sonography with a specially developed 20 MHz flexible catheter-based high-resolution, real-time miniature (2.4 mm outer diameter) ultrasound transducer in primary infertile women (n = 15) with a normal menstrual cycle. All the women had <2 years infertility duration and were studied in proliferative, and early or mid-secretory phases. Before intrauterine sonography, transvaginal sonographic assessment of the endometrium was conducted. The overall image clarity was subjectively compared between intrauterine and transvaginal sonography. Most endometrial textures in both proliferative and secretory phases were viewed more easily with intrauterine rather than transvaginal sonography, and this was especially true with an intrauterine saline infusion technique. Moreover, it was possible to obtain finer image quality of very small endometrial interfacial and internal textures with intrauterine sonography. However, the depth of penetration of the ultrasound beam is only approximately 2 cm, therefore examination of larger pathological endometrial lesions is markedly limited because of the shallow scanning range of the high-frequency transducer. Intrauterine sonography may be a valuable tool in imaging endometrial texture in normal menstrual cycle, and possibly in infertility practice, complementing and not replacing transvaginal sonography.     

枕颈部三维运动范围的测量

目的：研究枕颈部正常的三维运动范围，为枕颈部不稳分析和治疗提供生物力学基础。方法：运用脊柱三维运动测量分析系统，对１１具成人新鲜枕颈部标本的三维运动范围进行测试。结果：寰枕关节的前屈、后伸、左／右侧屈、左／右轴向旋转运动范围分别是：１１．７°、９．６°、２．８°／２．７°、６．９°／５．４°；寰枢关节分别为：８．９°、５．９°、３．４°／４．２°、３７．５°／３８．７°；寰枢关节中性区为２７．４°，占主运动范围的７１．７％；枕颈部与脊柱其它部位相比，主运动时伴有更明显的藕合运动，屈伸、侧屈时伴有比主运动范围更大的藕合旋转运动，分别为１０．５°、１４．３°。结论：脊柱三维测试分析系统不仅能对枕颈部的三维运动范围进行精确的测量，且能反映枕颈部三维运动的特点。     

Implantable data logging system for heart rate and body temperature: its application to the estimation of field metabolic rates in Antarctic predators

The metabolic rate of free-ranging animals is difficult to measure, but of great importance in understanding the interactions of a species with its environment. Heart rate can, if correctly validated and calibrated, give an estimate of metabolic rate, with both a fine time resolution and over long periods. The telemetry of heart rate is well documented, but is not appropriate over long ranges (possibly several thousands of kilometres) or for diving species. An implantable data logger has therefore been developed for the long term recording of heart rate and body temperature. The logger is built using hybrid and ASIC construction techniques, weighs 20 g and measures 55×24×6 mm. The device is programmable, and its solid-state memory holds over 70 days of data if, for example, heart rate is counted and stored every minute. Current consumption is 155 μA while logging, 50 μA during a programmable initial delay period, and less than 1 μA when the logger closes down after filling its memory. These loggers have been deployed for two field seasons in gentoo penguins, black-browed albatross and fur seals.     

Principal component analysis of chest wall movement in selected pathologies

A method is presented for assessing a compact set of parameters characteristic of respiratory system functional status. 3D movements of points in the chest wall and the volumes of chest wall compartments (pulmonary rib cage, abdominal rib cage and abdomen) are considered. The co-ordinates of these points are measured using an optoelectronic system for 3D motion analysis. Principal component analysis is applied to these data. The behaviour of the eigenvectors of the covariance matrix of the 3D co-ordinates of the points on the chest wall shows close agreement with the pathology characteristics. The same is found for the percentage of total variance explained by the principal components of the volume variations. In this case, the higher values of variance percentage explained indicate independent motions (active or passive) in the degrees of freedom of the system identified by partitioning the total volume into compartments.     

心传导束相关特异性抗体制备及其在心脏疾病检测中的初步应用

目的：研发和制备心钠肽（ANP）的兔单克隆抗体,检测其在心窦房结、传导束的免疫特性表达及其在心 脏疾病中的检测应用。方法：采用固相多肽合成法合成ANP 特异性多肽,对新西兰大耳白兔进行免疫,取出兔 脾细胞与兔的骨髓瘤细胞240E-W3 进行融合,采用兔单克隆抗体技术制备兔单抗,运用免疫印迹、免疫组织化 学法鉴定其特异性和敏感性。收集24 例人心组织,其中呼吸系统疾病、心血管系统疾病、其他疾病导致死亡的 比例分别占33%、54%、13%,对24 例人心组织进行免疫组织化学检测ANP 表达。结果：制备抗ANP 的兔单克 隆抗体（ab225873）,经免疫印迹检测显示,ANP 在人心组织中可以特异性识别大小为16 kD 的条带。免疫组织 化学结果显示,ANP 特异性表达在成人心组织的窦房结和左心室的传导束,但心室肌以及成人的其他组织中不表 达。24 例人心组织中心房肌阳性率为100%,窦房结阳性率为100%,传导束阳性率为50%,心室肌阳性率为0。 结论：本研究制备的抗ANP 兔单克隆抗体（ab225873）在免疫印迹和免疫组织化学上均表现有良好的特异性与敏 感性,能特异识别心窦房结、传导束,为研究窦房结、传导束相关疾病提供分子检测工具。     

信号转导子和转录激活子6及其mRNA在哮喘大鼠气道炎症中的作用

目的：探讨信号转导子和转录激活子6(STAT6)及其mRNA在哮喘大鼠气道炎症中的作用。 方法： 20只二级雄性SD大鼠随机分为2组, 对照组和哮喘组。以卵清白蛋白(OVA) 致敏激发法复制大鼠哮喘模型，每只大鼠左肺留取肺组织，右肺进行支气管肺泡灌洗并留取支气管肺泡灌洗液(BALF)。对BALF进行细胞总数、嗜酸性粒细胞(EOS)计数和分类计数；应用双抗体夹心酶联免疫吸附试验（Sandwich ELISA）法测定BALF和血清中IL-4浓度；采用免疫组化法和原位杂交法测定STAT6蛋白和STAT6 mRNA的表达情况。 结果： (1) BALF和血清中白细胞介素4(IL-4)的浓度哮喘组均显著高于对照组(均P<0.01)；(2)免疫组化和原位杂交显示，哮喘组支气管STAT6蛋白和STAT6 mRNA的表达均显著高于对照组(均P<0.01)，其主要表达细胞是上皮细胞；(3)支气管上皮细胞STAT6蛋白及其mRNA含量分别与BALF中的IL-4浓度、EOS绝对值呈非常显著正相关。 结论： 哮喘大鼠STAT6蛋白和mRNA高表达，上皮细胞是其主要表达细胞，并与IL-4浓度、EOS募集密切相关。     

应用微种植支抗大鼠牙齿移动过程中牙周组织OPN的表达变化

目的　观察应用微型种植支抗使大鼠牙齿移动过程中骨桥蛋白（OPN）的表达变化,探讨其在成骨细胞诱导和骨改建中的作用。 方法　建立应用微型种植支抗牵引移动大鼠下颌第一磨牙的实验模型。OTM组在大鼠右侧下颌做加力牵引,左侧下颌作为对照组,分别于OTM后 2、4、7及14 天,解剖分离大鼠下颌骨,HE染色观察组织形态,免疫组织化学检测OPN表达变化及时间分布特点。 结果　HE显示OTM组中张力侧成骨细胞、压力侧破骨细胞表达较多。免疫组化显示OTM组OPN阳性细胞数随加力时间的增加而增加,第7天达到高峰,此后逐渐降低。 结论　在正畸牙移动过程中,OPN表达的变化规律与骨改建过程中成骨细胞分化、形成和功能密切相关,与牙槽骨改建过程一致。     

海南地区(汉族)新生儿心脏的解剖学观察

目的提供国人新生儿心脏的解剖学资料,为临床新生儿心脏超声诊断提供解剖学依据。方法选取发育正常新生儿尸体,10%福尔马林灌注后行直视下解剖学测量,获取心的重量、体积、各房室壁及室间隔厚度、心室流出道长度、乳状肌数目、腱索数目等数据,并与已知国人参考值进行对比。对12例有生前B超资料的与相关解剖学测量值进行配对t检验。结果心的重量、体积、冠状沟周径、心的长、宽、厚、左右心室流出道、乳头肌长度、腱索的数目小于参考值(P<0.01);房室壁厚度、乳头肌数目与参考值无差异(P>0.01);房室壁及室间隔厚度、心室流出道长度的B超值小于解剖学测量值(P<0.01)。结论海南地区(汉族)新生儿心脏重量?体积的解剖学测量值小于参考值;新生儿心脏B超测量值与解剖学测量值可能存在差异?     

Sonographic measurement of lateral parapharyngeal wall thickness in patients with obstructive sleep apnea

INTRODUCTION: Lateral parapharyngeal wall (LPW) thickness may be a predominant anatomic factor causing airway narrowing in apneic subjects. In this study, we explored sonographic measurement of the LPW thickness and compared the results with LPW thickness measured by magnetic resonance imaging (MRI). We also investigated the association between sonographic measurement of LPW thickness and apnea-hypopnea index (AHI). METHOD: Seventy-six patients with suspected obstructive sleep apnea (OSA) underwent ultrasound examination of LPW thickness after overnight polysomnography. Fifteen out of 76 subjects also participated in correlation and reliability studies of sonographic and MRI measurements of LPW thickness. RESULTS: There was good correlation between measurements of LPW thickness on ultrasound and MRI (r = 0.78, P = 0.001), although Bland-Altman analysis indicated overestimation of LPW thickness by ultrasound, when compared with the LPW as measured by MRI. The sonographic measurement of LPW thickness had high reproducibility, with intraclass correlation coefficients of 0.90 and 0.97 for intraoperator and interoperator reliability, respectively. Fifty-eight subjects with significant OSA (AHI > or = 10/h) had a higher body mass index, larger neck circumference, and greater LPW thickness measured by ultrasound than those (n = 18) with an AHI of less than 10 per hour. LPW thickness had a positive correlation with AHI on univariate analysis (r = 0.37, P = 0.001). On multivariate analysis, LPW thickness had a positive independent association with AHI after adjustment for age, sex, neck circumference, and body mass index. The positive association of LPW thickness with AHI remained significant in both univariate and multivariate analyses of men only (n = 62). CONCLUSIONS: Sonographic measurement of LPW thickness is a novel and reliable technique and had good correlations with measurement by MRI and the severity of OSA. Ultrasound may provide an alternative imaging modality with easy accessibility and lower cost in OSA research.