By Topic

Biomedical Engineering, IEEE Transactions on

Issue 1 • Date Jan. 1975

Filter Results

Displaying Results 1 - 23 of 23
  • Table of contents

    Page(s): c1
    Save to Project icon | Request Permissions | PDF file iconPDF (808 KB)  
    Freely Available from IEEE
  • IEEE Engineering in Medicine and Biology Group

    Page(s): c2
    Save to Project icon | Request Permissions | PDF file iconPDF (160 KB)  
    Freely Available from IEEE
  • Diagnosis of Urethral Flow Parameters by Ultrasonic Backscatter

    Page(s): 1 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3606 KB)  

    Earlier reported tests have demonstrated that sufficient ultrasonic scattering can be obtained from particulate matter in urine during voiding to be of value as a transcutaneous diagnostic technique for the lower urinary tract. In this paper, we compare theoretical scattering computations for urethral flow models with data obtained from scattering measurements on the urethra and on physical models. The results indicate that urethral parameters such as the average urine velocity, extent of turbulence, and urethral diameter as a function of position along the tract, including the location of any strictures, can be determined remotely by ultrasonic means. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Nuclear Magnetic Relaxation in Blood

    Page(s): 12 - 18
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2073 KB)  

    The nuclear magnetic relaxation time T1 of protons in human blood has been measured as a function of frequency, pH, and hematocrit. For whole blood at 25°C, T1 is approximately 0.1 s at 20 kHz, increasing to approximately 1 s at 50 MHz. T1 of whole blood is analyzed in terms of the exchange of water molecules between plasma and erythrocyte cytoplasm. A cellular residence time of 19 ms provides the best fit to the data. The T1values for plasma and cytoplasm are explained in terms of their protein content, using the well-established theory of nuclear relaxation in macromolecular solutions. The plasma and cytoplasm data are compared with previous T1 results for apotransferrin and hemoglobin solutions, respectively, and qualitative agreement is found. The T1 values increased with decreasing pH, as is expected from existing data on hemoglobin solutions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pattern Recognition Applied to Monitoring Waveforms

    Page(s): 18 - 24
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1715 KB)  

    This paper demonstrates that fetal heart rate (FHR) patterns can be classified by algorithmically determined linear discriminants. A nonparametric learning algorithm was applied to 17 samples of five-vectors. The coordinates of each sample vector were visual features derived from the FHR curve and the simultaneous uterine contraction pressure data in accord with medical training-literature. Data were obtained from strip-chart recordings from the Cedars-Sinai Medical Center, Los Angeles, where an FHR monitoring and on-line computer processing system based on an IBM System/7 is being installed. The algorithm converged to linear discriminants that correctly classified all the 17 training samples under four different combinations of initial weights, training sequence, and correction increment. Each of the four linear decision rules so obtained was applied to 14 new sample vectors. Three classified 11 samples correctly and one classified 13 samples correctly. Medical anomalies (atypical data) were present in all three misclassified patterns. A perfect success record was found in classifying all seven medically ominous new sample vectors. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Electrically Calibrated Plethysmograph for Direct Measurement of Limb Blood Flow

    Page(s): 25 - 29
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3110 KB)  

    This paper describes an electrically calibrated plethysmograph which may be used with all lengths of mercury-in-rubber strain gauges. Due to the very low resistance of these strain gauges, electrical calibration of previously available plethysmographs has suffered from errors caused by lead-wire resistance. The present instrument eliminates lead-wire errors by a design which effectively places the strain gauge at the corners of the measurement bridge. Linearity of the output for large changes in gauge resistance has been insured by the incorporation of a constant-current bridge supply. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Detection of Digitalis Toxicity by Computerized Electrocardiogram Monitoring

    Page(s): 29 - 34
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1423 KB)  

    A new ECG monitoring technique is described which can detect the condition of digitalis toxicity prior to the onset of arrhythmias. The technique is based on experiments with mice in which digitalis toxicity was induced by the administration of the cardiac glycoside, ouabain. Results are shown in which spreading of the QRS complex is a consistent precursor of premature ventricular contractions and ventricular fibrillation. Both high and low dose studies are described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Localization of Cellular Structures

    Page(s): 35 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4499 KB)  

    A technique for the localization of cytoplasmic and nucleic material in Wrights and Wrights-Giemsa strained blood cells is described. The microscopic field of view is first scanned with three different wavelengths of light and then digitized with the aid of a microscopic/vidicon/computer. Each of the three pictures is then converted to a binary color picture by comparison with three calculated clipping levels. The three binary color pictures are then logically combined to generate ``masks'' or sets of points which correspond to 1)nucleic points in the picture, 2) cytoplasmic points in the picture, and 3)red-cell points in the picture. The algorithms involved are easy to implement either in hardware or software, and execute very rapidly in either environment. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Design of a Piezoelectric Heart Assist Device

    Page(s): 40 - 46
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2593 KB)  

    A piezoelectric heart assist device was designed, and preliminary tests were performed in vitro and in vivo. The device has the advantages of simple construction, low power consumption (approximately one watt), electrical rather than pneumatic drive, and noiseless operation. The device consists of piezoelectric bender elements forming two cantilevers. A unique feature of the device is that two tungsten alloy masses, 0.44 kg each, were added to the free ends of the cantilevers to reduce the resonant frequency to 2.5 Hz. The driving voltage was a 320 V peak-to-peak square wave synchronized with a paced heartbeat. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • In Vivo Modeling for Glucose Homeostasis

    Page(s): 47 - 52
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1835 KB)  

    A model for the glucose-insulin control system has been developed. The primary controllers in this model are the pancreas and liver. These subsystems operate within the metabolic environment to maintain normal glucose levels. The prime control variables for each subsystem, as well as for systemic glucose utilization, are the plasma glucose and insulin concentrations perfusing these organs. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Threshold Determination by Titration: A Markoff Chain Model

    Page(s): 53 - 57
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1141 KB)  

    Threshold is often defined as that stimulus intensity which is correctly detected 50% of the time. A titration procedure increases the stimulus intensity by a fixed increment if the subject fails to detect the stimulus, and decreases the stimulus if it is detected. The mean stimulus intensity thus obtained is an estimate of threshold. The Markoff chain model developed here allows the mean and variance of the mean to be calculated for any specified stimulus values, number of trials, and distribution of the underlying variate. Examples are given to illustrate the effects of changing the experimental parameters and the underlying distribution. The titration mean was fairly insensitive to these changes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Mechanism of Cutting in Electrosurgery

    Page(s): 58 - 62
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1439 KB)  

    A detailed analysis shows how electrosurgical r-f power is localized in the vicinity of the cutting electrode. This localization requires a small radius of curvature for the surgical tip, relatively high r-f voltages, and rapid surgical tip motion. The erratic results sometimes encountered in electrosurgery may be due to a deficiency in the above procedures as well as a lack of care in the use of the r-f leads and ground plates. A further analysis supports the supposition that evolving steam bubbles in the tissue at the surgical tip continuously rupture the tissue and are responsible for the cutting mechanism. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Grounding and Safety

    Page(s): 62 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2600 KB)  

    Several basic facts about the effects of steel conduits in A.C. power systems are reviewed to show that the geometry of a grounding path may have a greater effect on its effectiveness as a ground return path than its D.C. resistance. Data are presented on the effect of ¿¿ E.M.T. conduit and No. 10 conductors in tests simulating regular room wiring under ground fault conditions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Feedback Controlled Stimulator That Delivers Controlled Displacements or Forces to Cutaneous Mechanoreceptors

    Page(s): 66 - 69
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1260 KB)  

    Based on a design by the root locus method and utilizing both displacement and force feedback an instrument is described which can be used to deliver either controlled displacement or controlled force stimuli to the skin. Examples of the stimulator operated in each of its two modes are given. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Inexpensive Device for Determining Sinus Node Function and the Refractory Periods of Cardiac Conduction Systems

    Page(s): 69 - 71
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (968 KB)  

    A simple, inexpensive device capable of measuring the refractory period of the cardiac conducting system has been described. All components used in the device may be purchased for less than $150 and commercial equipment capable of performing similar tasks costs over two-thousand dollars. The undesired features of previous methods have been eliminated and results of using the device in clinical settings have been given. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • EEG Spectra Measured with a Distorting System

    Page(s): 71 - 74
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (994 KB)  

    The distortion effects upon the measurement of EEG spectra are investigated. A non-linear model of zero-memory type is used for the input-output relation of the measurement system. The model is identified by means of measured second and third harmonics. Examples illustrate the distortion effects upon power spectra of waking infant and adult EEG's. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Microwave Properties of Fresh Mammalian Brain Tissues at Body Temperature

    Page(s): 74 - 76
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (811 KB)  

    The complex dielectric constant of human, primate, canine, ovine, and swine brain tissues at 37°C was measured in S band using a slotted waveguide section. The in vitro measurements indicate that mammalian brains exhibit very little dispersion within the frequency range of 2.25 to 3.95 GHz. The dielectric constant was found between 30 and 35 and the conductivity varied from 1.1 to 3.1 mho/m. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Versatile Temperature Controlled Exposure Chamber for Microwave Bioeffects Research

    Page(s): 76 - 77
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1606 KB)  

    A versatile temperature controlled microwave exposure chamber has been designed especially for use in microwave bio-effects research. The device uses a thermoelectric heat pump to cool the air in the chamber below ambient and a resistive heater for above ambient operation. A unique feature of the exposure chamber is that the radiating antenna can be either inside or outside of the chamber. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Effect of Radial Node Spacing on Finite Difference Calculations of Temperatures in Living Tissues

    Page(s): 77 - 80
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2021 KB)  

    Finite difference calculations of the transient radial temperature distribution in living tissue are compared with an analytical solution in which metabolism, blood flow rate, and arterial blood temperature vary with time. The effects of node spacing and integration time interval on the accuracy of the finite difference calculations are investigated. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Effect of Radial Nodal Spacing on the Performance of a Mathematical Model of the Human Temperature Regulatory System

    Page(s): 80 - 83
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1122 KB)  

    A mathematical model of the human temperature regulatory system has been constructed and tested. The number of finite difference nodes used to approximate the radial temperature distribution in each of the major body elements was independently varied. For exposure to warm environments, a four node unequally spaced configuration is adequate, while ten nodes unequally spaced are adequate in cold air environments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contributors

    Page(s): 84 - 88
    Save to Project icon | Request Permissions | PDF file iconPDF (5693 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Biomedical Engineering Statement of Editorial Policy

    Page(s): 88-a
    Save to Project icon | Request Permissions | PDF file iconPDF (277 KB)  
    Freely Available from IEEE
  • Institutional listings

    Page(s): 88b
    Save to Project icon | Request Permissions | PDF file iconPDF (53 KB)  
    Freely Available from IEEE

Aims & Scope

IEEE Transactions on Biomedical Engineering contains basic and applied papers dealing with biomedical engineering. Papers range from engineering development in methods and techniques with biomedical applications to experimental and clinical investigations with engineering contributions.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Bin He
Department of Biomedical Engineering