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Biomedical Engineering, IEEE Transactions on

Issue 6 • Date Nov. 1974

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Displaying Results 1 - 23 of 23
  • Table of contents

    Publication Year: 1974 , Page(s): c1
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  • IEEE Engineering in Medicine and Biology Group

    Publication Year: 1974 , Page(s): c2
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  • Computer Modeling of Nonsteady State Sodium Kinetics in Liver

    Publication Year: 1974 , Page(s): 433 - 443
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2909 KB)  

    The exchange of materials in biologic tissues can be quantitatively described by transport rate constants (k's). One way to determine these k's is from studies of tissue fragments with the aid of an isotope as tracer and digital computer simulation. Usual methods of solution require that the material of interest, tracee, remain at steady state during the in vitro outflow recording period. When Na kinetics is studied in liver fragments, it is found that this tissue keeps absorbing Na tracee from the in vitro medium, thus departing from in vivo and yielding a nonsteady state. View full abstract»

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  • The Measurement of Total Lung Capacity Based on a Computer Analysis of Anterior and Lateral Radiographic Chest Images

    Publication Year: 1974 , Page(s): 444 - 451
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4403 KB)  

    This paper addresses the problem of computing the total lung capacity (TLC) without operator intervention by means of the picture analysis of the anterior and lateral X-ray images. Barnhard's ellipse method was employed which requires as parameters such features as the top of the diaphragm in both views, and the width of the heart in the lateral view. View full abstract»

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  • Extracellular Stimulation of a Cell Having a Non-Uniform Membrane

    Publication Year: 1974 , Page(s): 452 - 460
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2056 KB)  

    The response to extracellular simulation of a cell having a non-uniform membrane consisting of a low resistance patch in an otherwise high resistance membrane is examined. The presence of the patch is shown to cause a shift in the isopotential value of the intracellular medium towards the value of potential just outside the patch. The quantitative dependence of this shift upon the electrical parameters of the system is examined; the effect of such a shift upon the distribution of induced transmembrane potentials is discussed; and the case of a cell with multiple low resistance patches is treated. View full abstract»

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  • The Use of Time Dependent Models in Inverse Electrocardiography

    Publication Year: 1974 , Page(s): 460 - 468
    Cited by:  Papers (3)
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    This study investigates the feasibility of utilizing multiple dipole cardiac generators with time dependent dipole moments to obtain physiologically feasible inverse electrocardiographic solutions. View full abstract»

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  • The Use of Intrinsic Components in an ECG Filter

    Publication Year: 1974 , Page(s): 469 - 473
    Cited by:  Papers (20)
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    The problem of filtering artifact from QRST complexes of ECG records has been approached by the use of a digital, time-varying filter. The optimum form of this filter assuming uncorrelated, zero-mean, additive noise is presented and shown to be equivalent to estimating the coefficients of an intrinsic component expansion of the complex. Results are reported showing that QRST complexes in limb leads of normals may be accurately represented by only eight terms of the intrinsic component expansion. A suboptimum filter is presented and results reported which show that an order of magnitude reduction of the 0.05 to 100 Hz artifact energy in the filtered complex can be achieved. View full abstract»

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  • Wavelike Properties of the Alpha Rhythm

    Publication Year: 1974 , Page(s): 473 - 482
    Cited by:  Papers (32)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3142 KB)  

    Apparent similarities between brain waves and physical waves are considered. The distribution of power in the alpha rhythm over frequency and spatial wavelength is measured in several subjects. This is accomplished by means of spatial-temporal Fourier analyses of scalp surface potentials using multichannel recordings from electrodes placed along the midline. It is found that the spectrum of midline alpha oscillations peaks for long wavelengths (¿20 cm). A dispersion relation relating frequency to spatial wavelength apparently exists for frequencies near the peak alpha frequency. That is, in all 13 records, frequency components just above the peak alpha frequency have shorter midline wavelengths than low alpha frequency components. The relationship of these results to theoretical descriptions of the EEG and to other experiments is discussed. View full abstract»

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  • Bevelled Dual-Channel Microelectrodes

    Publication Year: 1974 , Page(s): 482 - 485
    Cited by:  Papers (11)
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    Preparation of bevelled dual-channel glass microelectrodes is described. The bevelled tips overcome some of the problems which complicate intracellular recording. The size of the tip opening is increased, resulting in a lower resistance, which in turn confers greater current-carrying capacity and less noise susceptibility. Bevelling also preserves the sharp point, facilitating tissue penetration and minimizing neuronal trauma. The characteristics of bevelled and unbevelled electrodes filled with 0.5 or 3 M KCI, K Acetate and K2SO4 were similar. Bevelled electrodes were shown to maintain a near constant resistance during current passage, while unbevelled ones showed changes in resistance that were dependent on current magnitude, polarity and duration. Such changes were caused principally by electro-osmosis. View full abstract»

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  • An Integrated Field-Effect Electrode for Biopotential Recording

    Publication Year: 1974 , Page(s): 485 - 487
    Cited by:  Papers (79)  |  Patents (6)
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    An integrated liquid-oxide-semiconductor FET structure is described. The structure is similar to a conventional n-channel depletion mode MOSFET except the gate metal is omitted. Immersing the device in a saline solution, the drain current is controlled by the potential between the source and the solution. Operated as an active recording electrode, the structure has several properties useful in neurological research. View full abstract»

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  • An Evaluation of the Resistance to Electrolysis of Metals for Use in Biostimulation Microprobes

    Publication Year: 1974 , Page(s): 487 - 490
    Cited by:  Papers (14)
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    Electrolysis measurements have been made on electrodes of platinum, stainless steel, tungsten, iridium, palladium, rhodium, rhenium, gold, tantalum, titanium, zirconium, and some conducting oxides of the tungsten bronze family. Electrodes were immersed in physiologic saline solution and subjected to biphasic rectangular current pulses of various current densities at 50 pps, 24 hours per day for periods up to nine months. Weight loss was recorded at intervals during this time. We conclude that iridium,rhodium, platinum and palladium are extremely resistant to electrolysis under these conditions and electrolysis under 5¿ thick, made of such materials should have lifetimes on the order of decades. Gold is somewhat poorer but probably acceptable; all the other materials tested, including tungsten and stainless steel, are unacceptable as chronic microelectrode materials. View full abstract»

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  • The Conductivity and Dielectric Constant of a Sphere Determined by Scattered Field Measurements

    Publication Year: 1974 , Page(s): 490 - 492
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    Modeling the human skull as a homogeneous sphere, a method is presented whereby the unknown conductivity and dielectric constant associated with the sphere can be determined through measurements of the Stokes polarization parameters of the angularly scattered radiation, when the sphere is irradiated by an electromagnetic plane wave. The wavelength of the incident field is on the order of the diameter of the sphere so that the Mie description of the scattered field is employed. The technique requires the minimization of the square of the differences between the measurement and its theoretically computed counterpart. A simple systematic variation in the unknown parameters (complex refractive index) is utilized for the minimization process. Numerical illustrations of the method are presented for computer simulated measurements. View full abstract»

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  • Comments on "Threshold 60-Hz Current Required for Ventricular Fibrillation in Subjects of Various Body Weights

    Publication Year: 1974 , Page(s): 493 - 494
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    Lead vector theory of electrocardiography is used to estimate cardiac current density thresholds for ventricular fibrillation from reported data for current thresholds at the skin. The estimated value, which is of the order of 300??A/cm2 is consistent with results obtained by others with 60 Hz currents injected directly into the heart. View full abstract»

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  • The Energy Conservation Equation for Living Tissue

    Publication Year: 1974 , Page(s): 494 - 495
    Cited by:  Papers (41)
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    The widely used bio-heat transfer equation is examined regarding its term describing the thermal effects of blood perfusion. It is demonstrated, both by physical arguments and numerical results, that the description of thermal convection by blood is inconsistent in this equation, and that results are in error by the same order of magnitude as the convective energy transport itself. View full abstract»

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  • On-Line Measurement of Airway Closing Volume

    Publication Year: 1974 , Page(s): 496 - 498
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    An on-line real-time program for measurement of airway closing volume has been developed, using the Lab-8/e (PDP-8/e) computer. The paper describes the procedure for measurement of airway closing volume and the program which was developed. The program in addition to measuring airway closing volume also measures the alveolar plateau volume, and the slopes of the alveolar plateau and the closing volume excursion. The program operates in conjunction with the Digital Equipment Corporation Pulmonary Test System. View full abstract»

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  • Frequency Content of Intravascular and Intracardiac Pressures and Their Time Derivatives

    Publication Year: 1974 , Page(s): 498 - 501
    Cited by:  Papers (2)
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    The purpose of this study was to determine the frequency content of intravascular pressures and their time derivatives. Pressures, recorded using catheter-tip manometers in patients undergoing diagnostic cardiac catheterization, were amplified, filtered (100 Hz) to minimize aliasing errors, and then converted to digital format at 200 samples/sec. After examination of the waveform to exclude obvious artefact, it was analyzed using a Fourier transform and then resynthesized using a decreasing number of harmonics. Peak dp/dt of both the original and resynthesized waveforms was computed until marked differences were observed. View full abstract»

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  • A Remark on Sensory Encoding of Two-Parameter Signals

    Publication Year: 1974 , Page(s): 501 - 502
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    A sensory system with two neurons can unambiguously code all two-parameter stimuli, even though the ``best value'' of one parameter is the same for both neurons. View full abstract»

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  • Contributors

    Publication Year: 1974 , Page(s): 502 - 504
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  • 1974 Index IEEE Transactions on Biomedical Engineering Vol. BME-21

    Publication Year: 1974 , Page(s): 504a - 504c
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  • Subject index

    Publication Year: 1974 , Page(s): 504c - 504g
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  • A look to your future

    Publication Year: 1974 , Page(s): 504-h
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  • IEEE Transactions on Biomedical Engineering Statement Of Editorial Policy

    Publication Year: 1974 , Page(s): 504-i
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  • Institutional listings

    Publication Year: 1974 , Page(s): 504j
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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