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Biomedical Engineering, IEEE Transactions on

Issue 6 • Date June 1982

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  • IEEE Transactions on Biomedical Engineering - Table of contents

    Page(s): c1
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    Freely Available from IEEE
  • IEEE Engineering in Medicine and Biology Society

    Page(s): c2
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    Freely Available from IEEE
  • Long-Term Neuroelectric Signal Recording from Severed Nerves

    Page(s): 393 - 403
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    Six recording electrode units were implanted around the severed sciatic nerves of rabbits immediately after an axotomy was performed. Voluntary and involuntary motor neuroelectric signals (including individual action potentials) were recorded from the surface of the severed nerve for as long as 142 days after implantation, the average duration being 64 days. In order to study the course of the limited duration of the signal detection, a stimulation electrode was implanted around the sciatic nerve proximal to the lesion; evoked neuroelectric signals were recorded throughout the length of the experiment. The impedance of the recording electrode was also measured throughout the length of the experiment. The behavior of the above parameters, combined with histological observations, indicated that nerve degeneration accounted for the deterioration of signal detection. View full abstract»

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  • EMG Pattern Analysis and Classification for a Prosthetic Arm

    Page(s): 403 - 412
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    This paper deals with the statistical analysis and pattern classification of electromyographic signals from the biceps and triceps of a below-the-humerus amputated or paralyzed person. Such signals collected from a simulated amputee are synergistically generated to produce discrete lower arm movements. The purpose of this study is to utilize these signals to control an electrically driven prosthetic or orthotic arm with minimum extra mental effort on the part of the subject. The results show very good separability of classes of movements when a learning pattern classification scheme is used, and a superposition principle seems to hold which may provide a means of decomposition of any composite motion to the six basic primitive motions, e.g., humeral rotation in and out, elbow flexion and extension, and wrist pronation and supination. Since no synergy was detected for the hand movements, different inputs have to be provided for a grip. The method described is not limited by the location of the electrodes. For amputees with shorter stumps, synergistic signals could be obtained from the shoulder muscles. However, the presentation in this paper is limited to bicep-tricep signal classification only. View full abstract»

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  • Theoretical Analyses and Computer Simulation of EGG Ventricular Gradient and Recovery Waveforms

    Page(s): 413 - 423
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    A discrete mathematical propagating model of the electrocardiogram is derived and used to describe and analyze a number of T-wave concepts: ventricular gradient, primary, secondary, and intrinsic T-waves. Several previously accepted, but inadequately justified ideas are precisely defined and rigorously developed. These include ventricular gradient, conditions for zero ventricular gradient, and the gradient's independence of activation sequence. Several new results are derived as well. Specifically, more general conditions for zero ventricular gradient in all leads are defined, the concepts of primary and intrinsic, as well as secondary T-waves are mathematically defined, it is shown that it is impossible to obtain the primary T-wave from the recorded and secondary T-waves by linear operations as has been suggested, the secondary T-wave is shown to be not uniquely definable, and computer-generated simulations illustrating many of the results are presented. View full abstract»

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  • Classification of Cortical Responses Using Features from Single EEG Records

    Page(s): 423 - 438
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    Our research goal is to develop a new methodology for studying brain function using single, unaveraged EEG records. This investigation has led to a new algorithm for feature extraction for the case of small design (learning) sets. The algorithm has been applied to extract features from unaveraged (single) EEG records, which consist of single evoked responses elicited from human subjects who read textual material presented in the form of propositions. The subjects were instructed to make a binary decision concerning each proposition. This gave two possible data classes. We selected features from the evoked event-related potentials (ERP's), and designed a classifier to assign the ERP's for each proposition to one of the two possible classes. View full abstract»

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  • Analysis of Periodic Structure in Model Subcellular Macromolecular Arrays by Fourier Processing of Single Line Video Signals in Scanning Transmission Electron Microscopy

    Page(s): 439 - 447
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    Fourier processing of single line video signals in scanning transmission electron microscopy (STEM) is a convenient and relatively objective method for the demonstration and characterization of the periodic structure present in thick sections of biological material where order cannot be readily determined by methods such as optical diffraction of transmission electron micrographs (TEM). Following alignment of the STEM scan vector with a prominent specimen axis, the video line signals, as visualized and focused in y-mode on the video monitor, were usually recorded on a digital signal processor for evaluation. The STEM line was frequency filtered, amplified, digitized, and subjected to fast forward Fourier transformation (FFT). Frequency space was examined by producing a power spectrum. Reverse Fourier transformations of the FFT, with appropriate frequency windowing, allowed separation of inherent specimen periodicities from background noise arising from various irregularities in the specimen and other sources. Pursuant to our studies on the neuroplasmic lattice of axons in neural tissue, we present here the results obtained with three model systems having spacings in the range of most interest with respect to subcellular macromolecular arrays (5-100 nm). Systems chosen were: 1) the lamellar structure of myelin sheath in cross section, 2) the lattice structure of tropomyosin crystals in thin sections, and 3) the cross-bridge lattice in longitudinal sections of squid mantle muscle fibers. These model tests show that information regarding periodic structure of materials can be obtained from economical single line scans rather than whole picture analysis. View full abstract»

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  • A Stimulator-Regulated Rapid-Freeze Clamp for Terminating Metabolic Processes of the Heart During Normal Physiological Working Conditions

    Page(s): 448 - 453
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    A stimulator-regulated rapid-freeze clamp has been developed by which squeezing action is used to forge the physiologically functioning rat heart into a 0.5 mm thick wafer, thereby freezing (-80°C) the entire heart, and thus terminating metabolic processes in 5 ms ±0.5 ms at any defined point in the contraction cycle. The pneumatic cylinders contain large ports and frictionless seals. 80 psi of compressed air drives the anvils at an overall rate of 0.14 in/ms. View full abstract»

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  • On-Line Detection of Respiratory Events Applied to Behavioral Conditioning in Rabbits

    Page(s): 453 - 456
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    The respiratory behavior of rabbits was analyzed to determine statistical features characteristic of exploratory sniffing. Statistical procedures and performance measures were incorporated into an on-line computer test to detect sniffing. The algorithm was employed in behavioral research to detect respiratory responses to conditioning stimuli in rabbits. The algorithm correctly sorted respiratory events from nonevents with an accuracy of 98 percent when compared to visual classification of polygraph tracings. View full abstract»

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  • 1/f Fluctuation of Heartbeat Period

    Page(s): 456 - 457
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    It is found that a heartbeat period fluctuation usually has a power spectral density which is inversely proportional to frequency, to which a spike is added at a breathing frequency. View full abstract»

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  • Fetal Electrocardiogram Enhancement by Time-Sequenced Adaptive Filtering

    Page(s): 458 - 460
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    An adaptive method for performing optimal time-varying filtering of nonstationary signals having a recurring statistical character, e.g., recurring pulses in noise, has been proposed. This method, called time-sequenced adaptive filtering, is applied to the enhancement of abdominally derived fetal electrocardiograms against background muscle noise. It is shown that substantial improvement in terms of signal distortion is obtained when time-sequenced filtering, rather than conventional time-invariant filtering, is employed. The method requires two or more abdominal channels containing correlated signal components, but uncorrelated muscle noise components. The location of the fetal pulses in time must be estimated in order to synchronize the filter's time-varying impulse response to the fetal cardiac cycle. View full abstract»

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  • Parameter Estipiates in a Five-Element Respiratory Mechanical Model

    Page(s): 460 - 463
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    Using four sets of forced random noise impedance data from each of five normal subjects and five patients with obstructuve lung disease, we computed parameter estimates for a three-element series model and a five-element parallel compartment model. For normal subjects, the five-element model provided no better fit to the impedance data than did the simple series model. Estimates obtained from normal subjects using this three-element model were reasonable and reproducible within 25 percent. For all subjects with lung disease, the five-element model provided a significantly (p 0.05) better fit than the three-element model. Estimates for parameters representing central inertance and resistance, airway compliance, and peripheral resistance were reasonable and reproducible-within 18 percent. However, estimates for the compliance of the lung and chest wall were more variable since measured impedance appeared to be insensitive to this parameter in the frequency range used. View full abstract»

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  • Phase-Locked Loop Measurement of Sarcomere Length with High Time Resolution

    Page(s): 463 - 466
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    A method for making high-speed measurements of sarcomere length directly from the muscle striation image is presented. A phase-locked loop is used with a self-scanned photodiode array to measure the spatial frequency of the striation pattern. Computation circuitry converts frequency to sarcomere length. The sarcomere length output has a resolution better than 2 nm at a sample rate of once every 250¿s. View full abstract»

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  • Fitting the Hill Equation to Data: A Statistical Approach

    Page(s): 467 - 469
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    A procedure is presented for fitting the hyperbolic Hill equation to data. The procedure is a maximum likelihood method applied to a statistical specification of the problem which allows for measurement errors in two dimensions. The procedure is found to give an excellent fit. Problems encountered with the estimation of parameters when the estimates are highly correlated due to improper spacing of the observations are discussed. View full abstract»

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  • On Quantitative Analysis of Periodicity in Neonatal Respiratory Signals

    Page(s): 469 - 472
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    A quantitative wavelet periodicity measure was defined. This measure allows the quantitative description of wavelet periodicity in the neonatal respiratory signal. An iterative algorithm for on-line estimation of the periodicity measure may be useful as one of the features for automatic evaluation of the state of consciousness in premature infants. View full abstract»

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  • Classification of Spectral Patterns Obtained from Eustachian Tube Sonometry

    Page(s): 472 - 477
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    Spectral patterns of sound transmission through the Eustachian tube (ET) have been obtained in a series of experiments designed to identify ET dysfunction. Previous studies of ET function using sonometry have relied on heuristic and somewhat arbitrary methods in interpreting the data. In this study, an automated classification algorithm was developed to separate these sonograms into three distinct groups. From a total of 150 sample spectra, 75 were used in the formation of learning sets. The remaining spectra were classified into these three groups using standard Bayesian techniques. Both parametric and nonparametric methods were applied in estimating conditional probability density functions. Results of classification are compared with an independent test of ET function. Agreement between our classifier and the results of the independent test was as good as 97.3 percent. The results of this study indicate that an automated classification procedure can effectively distinguish among the three major types of sonograms obtained from ET sonometry. View full abstract»

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  • 4th Annual IEEE-EMBS Conference

    Page(s): 477a - 477b
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    Freely Available from IEEE
  • Applications Invited for Transactions Associate Editor for Medical Imaging

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  • IEEE Transactions on Biomedical Engineering Statement of Editorial Policy

    Page(s): 477-d
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  • Institutional listings

    Page(s): 477e
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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