Proceedings of the 1991 IEEE Seventeenth Annual Northeast Bioengineering Conference

4-5 April 1991

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Displaying Results 1 - 25 of 112
  • Establishing constitutive relationships for soft biological tissues

    Publication Year: 1991
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (58 KB)

    Summary form only given. An algorithm is presented by which stress-strain relationships, or constitutive equations, for various soft tissues may be developed, and some of the pitfalls affecting the process are discussed. These concepts are illustrated using the lung as an example. Four elements are required for analysis of the deformation of a body: (1) the geometry of the body in question, (2) a ... View full abstract»

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  • Detection of EEG transients by changes in dimensional complexity

    Publication Year: 1991
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (31 KB)

    Summary form only given. A simple box accounting algorithm is applied to measure the fractal dimension of electroencephalography (EEG). Artificial transients of varying EEG characteristics are embedded. The change is noted in the fractal dimension within a window that is passed along the entire time series. Three embedded evoked potential spikes 100 ms apart buried anywhere in the time series are ... View full abstract»

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  • Evaluating the validity of the Oxylog in adults at rest and during exercise

    Publication Year: 1991, Page(s):147 - 148
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (163 KB)

    The reliability of a portable oxygen consumption meter (Oxylog) before its clinical utilization is determined by comparing simultaneously collected data from an Oxylog and a Medical Graphics 2001 metabolic cart during rest and bicycle ergometer exercise in normal adults. The results indicate differences in oxygen consumption and inspiratory ventilation values between the two systems. It is propose... View full abstract»

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  • Proceedings of the 1991 IEEE Seventeenth Annual Northeast Bioengineering Conference (Cat. No.91CH2997-5)

    Publication Year: 1991
    Request permission for commercial reuse | PDF file iconPDF (12 KB)
    Freely Available from IEEE
  • Oscillatory flow distribution at a bifurcation

    Publication Year: 1991, Page(s):85 - 86
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (128 KB)

    Flow-distribution in a 90° bifurcated airway during high-frequency oscillation is analyzed by numerical simulation. The parent and two daughter branches are of equal length and diameter, describing a T-junction rotated by 90°. The flow is considered laminar and incompressible, which is reasonable for small tidal volumes. The solution has been limited to two-dimensional channels, merely by ... View full abstract»

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  • Two and three-dimensional motion models for the left-ventricular wall

    Publication Year: 1991, Page(s):193 - 194
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB)

    The authors present a unified framework for visual motion tracking of nonrigid objects with specific applications to the left ventricular endocardial wall motion. The theory is based on differential geometry and considers both two-dimensional contours and three-dimensional surfaces and in each case uses an elastic model of the object with constraints on the types of motion allowed for tracking the... View full abstract»

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  • Preliminary results of IR spectroscopic characterization of cholesterol

    Publication Year: 1991, Page(s):175 - 176
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    The authors propose the use of skin over the bony prominences of the hands as a site for infrared (IR) exposure to measure blood cholesterol. Cholesterol, when exposed to IR radiation, generates an absorption spectrum Characteristic of its molecular composition. Aqueous solution of bovine cholesterol, (Sigma Chemicals) with 100mg% and 200mg% of concentration was exposed to laser using attenuated t... View full abstract»

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  • The actimeter: analyzing human functional mobility

    Publication Year: 1991, Page(s):149 - 150
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (184 KB)

    The actimeter is a device that measures and records gross human body movements. The data obtained from the actimeter are used to compare the body position profiles of disable-bodied individuals to those of able-bodied persons for the same occupation. The analysis of preliminary data obtained from actimeter tests indicate that the system is approximately 75% accurate. Error associated with the syst... View full abstract»

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  • Modeling neurite outgrowth on laminin in vitro

    Publication Year: 1991, Page(s):163 - 164
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (92 KB)

    Experimental parameters were measured and incorporated into a mathematical model to describe axonal outgrowth on the extracellular matrix molecule, laminin, in vitro. To elucidate the role of laminin and other basement membrane components in axonal growth and guidance, a systematic analysis of the effects of these various molecules on outgrowth characteristics such as the rate and direction of gro... View full abstract»

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  • A Hall-effect magnetic field detector

    Publication Year: 1991, Page(s):255 - 256
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    An accurate low-cost field detector was designed to measure the magnitude of magnetic flux density generated by 60 Hz AC. The Hall effect magnetic field detector was designed as an exposure assessment instrument that can provide the information needed to accurately conduct these epidemiologic studies. Though fields generated by high voltage transmission lines seem to be the focus of much public co... View full abstract»

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  • Neural network classification of EEG data generated through use of the audio oddball paradigm

    Publication Year: 1991, Page(s):7 - 8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    Single trial electrical brain evoked potentials were recorded using two different audio stimuli with unequal probabilities of occurrence. A modified self-organizing Kohonen neural network was used to organize the responses. The output of the network formed a topological map of the various component responses which included both changes in the evoked potential waveforms and the performance reaction... View full abstract»

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  • Sensitivity of phase III slope to FRC and breathing pattern in a single-path airway model

    Publication Year: 1991, Page(s):81 - 84
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    A numerical solution of the convection-diffusion equation with an alveolar source term in a single-path model (SPM) of airway gas transport simulates steady state CO2 washout. The SPM is used to examine the effects of independent changes to adjustable model parameters of lung volume and breathing pattern on the slope of phase III of the single breath CO2 washout curve. The pa... View full abstract»

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  • Structural stability prediction for thermoplastic ankle-foot orthoses

    Publication Year: 1991, Page(s):231 - 232
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB)

    A thermoplastic ankle-foot orthosis (AFO) is an orthotic appliance which extends from the calf to the foot. The solid ankle AFO (SAAFO) is used to provide forces and moments to correctly position the lower leg and foot so that more normal stance is achieved. The SAAFO is a thin shell structure, usually 3/32 to 3/16 in. thick, thermally vacuum formed to a cast representing the patient's lower leg, ... View full abstract»

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  • Impedance mapping of myocardial tissue during ischemia

    Publication Year: 1991, Page(s):189 - 190
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (132 KB)

    An impedance measurement system was developed for measuring myocardial tissue impedance (MTI) during ischemia in sheep and epicardial mapping system was developed that used a four electrode method with cardiac cycle gated and signal averaged measurements. After 60 minutes of ischemia, MTI increased by an average of 200% compared to non-ischemic tissue. A myocardial tissue model was developed which... View full abstract»

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  • A biomechanical study of a cervical spine stabilization device

    Publication Year: 1991, Page(s):24 - 25
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (200 KB)

    The biomechanical properties of surgically destabilized cervical spine motion segments are evaluated. The segments were fixed with spinal fixation plates and tested. The Roy-Camille spinal fixation plates were utilized as the stabilizing device. Results are compared with intact motion segments. It is shown that segments C3-4 and C4-5, when severely destabilized by a surgically created defect, can ... View full abstract»

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  • Automatic segmentation of cardiac images: texture mapping

    Publication Year: 1991, Page(s):202 - 203
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (124 KB)

    Image texture is used to segment left ventricular magnetic resonance (MR) images. The approach is built upon assumptions regarding those probability density functions (PDFs) present within the image. Specifically, an algorithm is constructed which assumes that the data are distributed as fractional Brownian motion (FBM). The FBM is parameterized by H, which quantifies the roughness presen... View full abstract»

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  • Mechanism of the voltage-induced conductance change in the Na channel

    Publication Year: 1991, Page(s):169 - 174
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB)

    A mechanism proposed for the voltage-dependent sodium channel postulates solid-state Na+ conduction through the polypeptide structure. Ion conduction is assumed to be state solid-state, through the protein subunits of the channel, rather than aqueous, through a hypothetical pore. The channel conformational change is taken to be a phase transition, with the closed state ferroelectric and... View full abstract»

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  • A parallel implementation of a multi-state Kalman filtering algorithm to detect ECG arrhythmias

    Publication Year: 1991, Page(s):239 - 240
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (172 KB)

    Detecting arrhythmias from the electrocardiogram (ECG) is of vital importance for the continued development of an intelligent cardiovascular monitor (ICM). The ICM's main goal is to present to the clinician a high-level analysis of the patient's condition based upon low-level physiologic signals (e.g., blood pressure, heart rate, etc.). The authors report on the parallel implementation of a multi-... View full abstract»

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  • An alternative mobility aid for the blind: the `ultrasonic cane'

    Publication Year: 1991, Page(s):158 - 159
    Cited by:  Papers (3)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    A design of a small portable electronic cane utilizing Polaroid's Ultrasonic Ranging Unit intended to supplement or replace the traditional long cane is presented. A prototype was fitted in a flashlight-like enclosure made of a PVC tube with an external battery pack as power supply and an ear-plug, for the audible output. Preliminary testing of the prototype with two blind individuals shows that s... View full abstract»

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  • An investigative study of membrane-based biosensors

    Publication Year: 1991, Page(s):253 - 254
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB)

    A system for incorporating naturally occurring membrane-based biological recognition elements into surface structures has been investigated. Alkylsilane molecules were covalently bound to the surface of a silicon/silicon dioxide (Si/SiO2) electrode as one half of a bilayer membrane mimetic structure. Detergent dialysis was then used to reconstitute lipids and proteins into the other hal... View full abstract»

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  • Modeling amplitude-modulated (AM) tone encoding behavior of cochlear nucleus neurons

    Publication Year: 1991, Page(s):5 - 6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    An attempt was made to understand the mechanisms underlying the response of the cochlear nucleus (CN) neurons, specifically the choppers, to the AM tone. The AM tone excitation via the auditory nerve fibers was modeled as a combination of DC, AC, and a zero-mean Gaussian noise current at the soma of the model neuron. The DC represents the high frequency carrier beyond the neuron's phase-locking li... View full abstract»

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  • Interaction of magnetic field with blood flow

    Publication Year: 1991, Page(s):79 - 80
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    A mathematical model governing steady laminar flow of an incompressible fluid subjected to a steady magnetic field including internal heating due to Joule effect, heat transfer due to conduction and convection, and thermally induced buoyancy forces has been developed. The thermal buoyancy was accounted for via Boussinesq approximation. To demonstrate effects of the Lorentz and Joule heating on the... View full abstract»

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  • Automated design of custom femoral stem prosthesis

    Publication Year: 1991, Page(s):56 - 59
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (180 KB)

    An automatic custom femoral stem capability has been developed and used to design prosthesis for several difficult cases not amenable to off-the-shelf components. The capability is based on the IDEAS package of programs. Computer tomography scan plates are digitized to generate cross-section profiles of inner and outer cortex. From these profiles a solid model is automatically generated. From the ... View full abstract»

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  • Bone graft translation of four upper cervical spine fixation techniques in a cadaveric model

    Publication Year: 1991, Page(s):229 - 230
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB)

    The goal of spinal fixation is to promote bony fusion by restricting motion at the site of the bone graft. In order to evaluate the efficiency of various cervical fixation techniques, the authors determined the translations at the posterior arch of C1 for four C1 -C2 posterior techniques: Gallie, Brooks, Mageri, and Halifax. The authors assumed that translational laxity is the critical motion para... View full abstract»

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  • Pulmonary input impedance spectra in models of chronically altered pulmonary hemodynamics

    Publication Year: 1991, Page(s):187 - 188
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (128 KB)

    Pulmonary input impedance spectra were estimated in one-month-old lambs whose circulation had been altered during the first few days of life to mimic the pulmonary. hemodynamic states observed in infants and children with left-to-right shunts (high flow) and /or pulmonary vascular obstructive disease (high pressure). Spectral results obtained from the animal models were compared with those obtaine... View full abstract»

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