多道阻抗血流图检测新方法

随着阻抗血流图临床应用的深入和电子与计算机技术的发展,血流图检测方法有了长足的进步,同时也存在不少问题,本文提出的多道血流图检查方法采用了一个公共的,以快速切换方式分时工人的恒流源,解决了同时使用两个或两个以上恒流源可能引起的信号混淆和干扰问题,新型血流图检测方法还应输出阻抗和导纳两套波形及测量参数,便于临床人员根据不同的应用要求选择使用,或进行对比研究,同时在血流图分析方面要包容更多的算法,可对心,脑,肺,肝,肾及肢体等器官进行血流图测量,分析,打印相应的报告,并为系统的功能扩充留有余地。     

一种新的分段生物电阻抗评估人体成分方法的实现：人体参数相关性分析

用分段生物电阻抗方法评估人体成分需测量人体各段的长度或横面积，增加了这种方法的复杂性。本文通过分析人体参数间相关性，得到了用性别、身高、体重表示的各段参数的线性回归等式，从而简化了分段阻抗法。     

Measurement techniques for assessing the influence of electromagnetic fields on implanted pacemakers

A method is described for assessing quantitatively the influence of electromagnetic fields on the function of implanted cardiac pacemakers. This influence may occur either indirectly by the action as an antenna of the catheter, or directly by induction into the pacemaker's electronic circuit. The technique comprises: measurement of the influence of electric voltages of various frequencies applied directly across the generator's output connections; determination of the aerial factor of the catheter configuration; combination of the data acquired to a diagram of overall sensitivity of the combination, in which a 10% variation of maximum output pulse amplitude, pulse width, or repetition rate of the pacemaker, whichever occurs first, has been chosen as a limit; comparison of this sensitivity/frequency curve with the electromagnetic field strength produced by several commonly used apparatus; and measurement of the direct influence of fields on the pacemaker itself. It is concluded, that disturbance of pacemaker action may occur in the vicinity of apparatus designed to produce electromagnetic fields, such as broadcast transmitters, diathermy applicators, and radar sets. Normal household appliances appear to be safe in the respect investigated.     

膝关节形态学测量在人工膝关节置换领域的价值及意义

背景：对人工膝关节假体形态尺寸进行观察及测量,并对相关测量统计数据进行人工膝关节形态设计,有利于促进膝关节假体植入后的稳定性和组织相容性。 目的：结合文献探讨形态学测量在临床上膝关节置换中的重要性。 方法：以 “膝关节;假体;测量;设计;置换”为中文关键词,以“artificial knee joint; prosthesis;measure;design;replacement” 为英文关键词。采用计算机检索1998-01/2011-12有关人工膝关节假体设计、测量及膝关节假体植入后相容性的文章。 结果与结论：膝关节的形态学测量即膝关节的三维有限元模型、相关参数及角度、生物力学研究与膝关节假体选择及设计有着重要相关性。膝关节的形态测量有二维和三维测量,以三维测量法精确。膝关节线性尺寸之间、身高与线性尺寸之间均有很好的相关性,所测量的数据在临床上均有应用意义。典型的膝关节三维解剖模型,能为膝关节参数的测量提供一种可靠的方法,提高手术的成功。     

Structural equation modeling using ability parameters: analysis of the situation where item parameters have been estimated by item response theory

One of the problems with structural equation modeling (SEM) is that the estimation of measurement equation is not separated from the estimation of structural equation. The main aim of this study was to propose a new method to overcome that problem by using ability parameters estimated by item response theory (IRT) as data. According to IRT, the error variance of measurement equation can be easily computed as the reciprocal of the information function. By using the estimates of the error variance, we can fix all parameters in measurement equation and can separate the estimation of structural equation from that of measurement equation. This method also allows us to estimate relations among factor scores with improved precision, because the errors of estimating factor scores are taken into account. The article concludes with a simulation result for verifying the efficacy of this method and an actual numerical.     

利用脉搏波特征参数连续测量血压的方法研究

通过研究血压与脉搏波特征参数的关系，提出了一个选择多个与血压相关的脉搏波特征参数,通过回归分析建立适合不同人的特征方程，进行血压的连续测量的新方法，为了验证测量结果的准确性；研制了张力计。实验结果表明：该方法具有较高的测量精度，可以应用于临床危重病人的血压监护和一般医学研究中，经过进一步地改进和完善后可应用于载人航天和日常动态环境。     

Impression technique for the assessment of oedema

A new instrument for the assessment of oedema based on the impression method is described. The measurement parameters are defined and the errors corresponding to the electrical and mechanical stability of the instrument are measured. The overall accuracy is calculated theoretically for the translocated volume. The accuracy and reproducibility are evaluated on plastic foam. The clinical procedure to measure oedema with this instrument is described. We show that the accuracy of the translocated volume parameter is very dependent on the overall stability of the instrument and that this instrument has an overall relative error of less than 7·3 per cent for a representative measurement. Experimental measurements on plastic foam show that the measurement parameters could be reproduced with standard deviations of less than 6 per cent and that the standard deviations for translocated volume are within the calculated overall relative error. Measurements on four patients with chronic oedema in an extremity show significantly different results on locations where pitting could be recognised compared to the contralateral nonoedematous extremity.     

Continuous Measurement of O2 Consumption and CO2 Elimination During a Wakeful Hypometabolic State

Abstract

A previous investigation has demonstrated that the practice of a meditational technique elicits a wakeful, hypometabolic state. Measurement of O₂ consumption and CO₂ elimination was made by sampling techniques; mean values of these parameters were calculated from 6–10 minute samples. The present study extends this investigation, using a recently developed method of continuous measurement of O₂ consumption and CO₂ elimination. Continuous measurement of these parameters permitted the determination of mean values for the entire experimental periods as well as for selected intervals and permitted the examination of the sequence of respiratory changes. The present study reports statistically significant decreases in O₂ consumption of 5 percent and CO₂ elimination of 6 percent for the entire 20 minutes of the meditation period. These are lower than the sample values of 16 percent and 15 percent reported in the previous study. However, when selected intervals of the meditation period are examined, decreases in O₂ consumption and CO₂ elimination are comparable to those previously reported. The results are consistent with the difference between the discontinuous sampling measurement method originally employed and the continuous measurement method of the present investigation.     

Analysis of facial sebum distribution using a digital fluorescent imaging system

Current methods for analysis of sebum excretion have limitations, such as irreproducible results in repeatable measurements due to the point measurement method, user-dependent artifacts due to contact measurement or qualitative evaluation of the image, and long measurement time. A UV-induced fluorescent digital imaging system is developed to acquire facial images so that the distribution of sebum excretion on the face could be analyzed. The imaging system consists of a constant UV-A light source, digital color camera, and head-positioning device. The system for acquisition of a fluorescent facial image and the image analysis method is described. The imaging modality provides uniform light distribution and presents a discernible color fluorescent image. Valuable parameters of sebum excretion are obtained after image analysis. The imaging system, which provides a noncontact method, is proved to be a useful tool to evaluate the amount and pattern of sebum excretion. When compared to conventional "Wood's lamp" and "Sebutape" methods that provide similar parameters for sebum excretion, the described method is simpler and more reliable to evaluate the dynamics of sebum excretion in nearly real-time.     

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.     

Measurement of Passband of Spatial-Frequency Channels of the Visual System

A method for measurement of the passband of spatial-frequency channels of a visual system is suggested. The spatial-frequency parameters were measured using differential threshold of flicker frequency. The results of experimental tests are considered. Translated from Meditsinskaya Tekhnika, Vol. 43, No. 3, 2009, pp. 33–35.     

A hydraulic-pouch method for assessing muscle dynamics

A simple method is described for measuring some mechanical parameters of flat muscle tissuein vivo. The method can be implemented with equipment normally found in a physiological laboratory with the addition of a few extra components. A small pouch is formed from the muscle, and into this is inserted a fluid-filled balloon which can be connected to a variety of hydraulic measurement circuits. The technical and physiological limitations of the system are discussed, and some representative measurements are given.     

示波法血压测量技术仿真研究

示波法血压测量技术是目前在血压自动测量仪器中被广泛采用的一种测量方法，这一方法的判据是通过大量的人群实验由统计学方法给出，因此这种测量方法必将造成个体测量之间的误差，有时误差是较大的，但是目前这一方法仍被广泛用于临床血压的监测。本文利用可塌陷管理论，根据示波法血压的测量过程和测量原理，建立了示波法动脉血压测量过程的物理模型，根据这种模型，在引用前人获取的模型参数的基础上对示波法血压测量技术进行了仿真。从仿真结果可以看出，示波法可以被用来监测同一人体血压随时间的变化，但在对不同个体进行测量时会导致测量误差。     

A Method for Identification of Nonlinear Equivalent Circuit Parameters of Electric Admittance of Skin

A method for identification of the parameters of the nonlinear equivalent circuit of electric admittance of skin is proposed. The circuit is represented by parallel connection of power-polynomial approximated nonlinear admittance and linear capacity in the presence of free-form current signal. A hardware–software system for nonlinear electrical skin admittance measurement is described. The range of linear and nonlinear skin admittance components was estimated using this system and polynomial approximation of degree three for test audience skin reflexogenic zones. The suggested method of verification for parameter identification of electrical skin admittance nonlinear equivalent circuit is accomplished.     

Intelligent Evaluation of Global Spinal Alignment by a Decentralized Convolutional Neural Network

Degenerative changes of the spine can cause spinal misalignment, with part of the spine arching beyond normal limits or moving in an incorrect direction, potentially resulting in back pain and significantly limiting a person’s mobility. The most important parameters related to spinal misalignment include pelvic incidence, pelvic tilt, lumbar lordosis, thoracic kyphosis, and cervical lordosis. As a general rule, alignment of the spine for diagnosis and surgical treatment is estimated based on geometrical parameters measured manually by experienced doctors. However, these measurements consume the time and effort of experts to perform repetitive tasks that could be automated, especially with the powerful support of current artificial intelligence techniques. This paper focuses on creation of a decentralized convolutional neural network to precisely measure 12 spinal alignment parameters. Specifically, this method is based on detecting regions of interest with its dimensions that decrease by three orders of magnitude to focus on the necessary region to provide the output as key points. Using these key points, parameters representing spinal alignment are calculated. The quality of the method’s performance, which is the consistency of the measurement results with manual measurement, is validated by 30 test cases and shows 10 of 12 parameters with a correlation coefficient?>?0.8, with pelvic tilt having the smallest absolute deviation of 1.156°.

     

A new method for the simultaneous measurement of the moment of inertia,the damping coefficient and the location of the centre of mass of a body segmentin situ

A new method which permits, in a single measurement, the determination of the moment of inertia, the angular damping coefficient of the joint and the location of the centre of mass of a body segmentin situ is presented. The underlying principle is the theory of small, damped oscillations of a system about its equilibrium position. The fact that the oscillogram contains information about certain parameters of the oscillating system is used to find these parameters. The application of the method is simple and does not require highly sophisticated instrumentation. The results are very reproducable and immediately available.     

血液凝固过程中粘度动态变化的测量方法及其临床意义的研究

探讨血液凝固过程中一种测量血液粘度动态变化的方法。设计的锥板粘度计由产生不同切变率的机械传动装置、放置血样的试样杯和锥板等装置组成。用8051单片机设计了PID检测控制系统，检测到的扭矩反映了血液粘度的变化。用此装置检测了鸡、兔、大鼠、及人的离体血液凝血过程中有物理性质改变的粘度指标，随时间变化的动态曲线及特征参数，表明此法可行、有效。分析在不同病理状态下的这些曲线和特征参数变化规律，有助于预报与防治血栓病，为研究血栓形成提供依据。     

A new approach to the computer-assisted quantitative analysis of nuclear shape

In recent years, researchers have explored the use of computer-assisted morphometric analysis to evaluate nuclear shape. Most of these studies use nuclear shape factors which are based on circumference/surface measurement ratios, such as variations of the nuclear contour index, the form factor, and the nuclear roundness factor. Here we present a new method for the objective evaluation of nuclear shape, involving a simple computer-assisted determination of nuclear area (N) divided by the area of a rectangular figure (F) with sides tangent to the nuclear margin and parallel to the frame of a video monitor. Following calculation of N/F for individual nuclei, our method generates statistical parameters for quantitating nuclear irregularity directly at the population level: the mean N/F ratio; standard deviation; and coefficient of variation. Our use of surface/surface measurement ratios makes our method independent of both magnification and nuclear size. Our method is applied first to normal lymphocytes and neutrophils to manifest the parameters for nuclear irregularity which are generated by our method. The sensitivity of our method is demonstrated using lymphoblasts from patients with acute lymphoblastic leukemia (ALL). Our objective ranking of nuclear irregularity for 20 cases of ALL correlates well with the subjective ranking of two pathologists. Because our method scores irregularity on a population basis and independently of other morphological criteria, it is compatible for use with the French-American-British (FAB) classification system (1981) for ALL.     

System for measurement and data reduction of meal-related parameters.

A system allowing accurate, simultaneous measurement of meal-related parameters such as meal size, meal duration and intermeal intervals for several animals is described. These measurements are made automatically, thereby reducing experimenter-animal interactions. In addition, a method for the automated definition and analysis of meal-related parameters is presented. Such a method provides a solution to the data reduction problem occurring in meal patterning research.     

Methods and devices for anode voltage measurement in x-ray apparatuses

Measurement of anode voltage of X-ray apparatuses is discussed. Operational parameters are considered and standard requirements for devices for noninvasive control of anode voltage are analyzed. A comparative specification table of modern X-ray apparatuses is presented. The dual-energy radiation method of measurement is described. Disadvantages of an indirect method of finding the practical peak voltage are shown.