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Proceedings of the Fifteenth Annual Northeast Bioengineering Conference

27-28 March 1989

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Displaying Results 1 - 25 of 117
  • Proceedings of the Fifteenth Annual Northeast Bioengineering Conference (Cat. No.89-CH2689-8)

    Publication Year: 1989
    Request permission for commercial reuse | PDF file iconPDF (9 KB)
    Freely Available from IEEE
  • Finite element model for the cardiac pump

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (51 KB)

    Summary form only given. To predict stress values within the myocardium and to explain the pumping action of the left ventricle, an axisymmetrical model has been formulated. The myocardium is a nonhomogeneous continuum made of an elastic matrix, plus a set of crisscrossed unidimensional helical fibers disposed in such a way that torsional motion is prevented. The fiber is characterized by its loca... View full abstract»

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  • Influence of background ions on the audio streaming potentials produced by human hairs

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (86 KB)

    Summary form only given. Human hair, unaltered by dyes or permanents, was collected to study the influence of various cations on the streaming potentials produced by pressure waves in the audio frequency range. The movement of potassium and sodium cations at the hair interface produced potentials which were markedly different for the two cations. It appears that the increased permeability and bind... View full abstract»

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  • Noise reduction for hearing aids

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (81 KB)

    Summary form only given. An overview is given of the various forms of signal processing for noise reduction that have been developed for hearing aid applications. One- and two-microphone systems are discussed. A more advanced form of a two-microphone system is also examined.<> View full abstract»

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  • Behavioral evaluation of noise suppression hearing aids

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (43 KB)

    Summary form only given. Hearing-aid manufacturers have introduced so-called smart noise-suppression systems that intelligently adapt in the presence of background noise, thereby improving the hearing-aid user's ability to hear under adverse listening conditions. How well hearing-aid users perform on speech recognition measures with commercially available noise suppression systems is addressed.< View full abstract»

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  • Evaluation of the efficiency of a newly developed permanent implantable mechanical cardiac assist device

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (82 KB)

    Summary form only given. A permanent implantable mechanical cardiac assist device has been developed to operate efficiently and to be easily implanted. The assist, a counterpulsation device, increases aortic pressure during diastole and reduces aortic pressure just prior to systole displacing a volume of blood. The efficiency and power required by the assist are important factors in evaluating the... View full abstract»

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  • Application of root locus technique to the model for pacemaker control of venous oxygen saturation level

    Publication Year: 1989, Page(s):73 - 74
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (96 KB)

    Summary form only given. A pacemaker-cardiovascular system sets a reference venous oxygen saturation level as the input and cardiovascular venous oxygen saturation as the output. The error drives the pacemaker with gain to regulate the heart rate. Cardiac output is obtained as a function of heart rate and the work load (using the Frank-Starling mechanism). The oxygen supplied by the blood is consu... View full abstract»

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  • Assessment of carotid stenosis as a source of reflected pressure waves using a transmission line model

    Publication Year: 1989
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (37 KB)

    Summary form only given, as follows. A transmission-line model is developed to assess the effects of carotid stenosis on the arterial pressure wave. In particular, the stenosis as a source of reflection is examined. The arterial system from the heart to the carotid bifurcation is modeled with a graded stenosis, representing a progressive atherosclerotic lesion simulated at the bifurcation. Within ... View full abstract»

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  • Motion analysis of upper extremity using six degree of freedom sensors

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (72 KB)

    Summary form only given. The accurate monitoring of extremity motion in the past has been a difficult and tedious task. A process has been developed using a McDonnel Douglas 3Space Digitizer and a Macintosh microcomputer which quickly and accurately provides motion data for a task involving general motion in three dimensions. The digitizer uses electromagnetic technology to create a field around a... View full abstract»

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  • Visual-vestibular interaction during rotation about the Earth horizontal axis

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (63 KB)

    Summary form only given. Seven human subjects were tested for visual-vestibular interaction (VVI) in a constant-velocity Earth horizontal axis (EHA) yaw rotation. This so-called barbecue-spit rotation provides an angular acceleration pulse to the horizontal semicircular canals and a constantly rotating gravity vector to the otolith organs. The subjects were tested with their eyes open in the dark ... View full abstract»

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  • Viscoelastic measurements in soft tissue

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (61 KB)

    Summary form only given. A study was made of viscoelastic changes in the limb in the presence of the compartment syndrome, which can occur when muscle tissues swell following trauma. Measurements were made of the applied pressure-volume displacement curves with a 1.4-cm/sup 2/ indenter placed on the limb surface above the compartment. The noninvasively measured viscoelastic departure from purely e... View full abstract»

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  • Evaluation of a model of visual-vestibular interaction

    Publication Year: 1989, Page(s):197 - 198
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB)

    Horizontal eye movements were recorded in normal subjects during tests of visual-vestibular interaction. The vestibular stimulation consisted of a step of angular velocity about the vertical axis. The optokinetic simulation consisted of full-field visual rotations at 0° and ±40°/s with respect to the head. The responses were simulated using a simple model of visual-vestibular intera... View full abstract»

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  • An alphabet for object detection and recognition

    Publication Year: 1989, Page(s):175 - 176
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (128 KB)

    The author introduces a novel object detection and recognition method using simple geometric primitives as building blocks of complex shaped objects. The method yields a robust recognition scheme and requires only two descriptors to characterize any object of the considered set. This results in an efficient database structure that allows addition of objects or rules in a straightforward fashion View full abstract»

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  • A nonlinear spectrum compression algorithm for the hearing impaired

    Publication Year: 1989, Page(s):21 - 22
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (132 KB)

    A technique is proposed for increasing the speech intelligibility of persons with profound sensorineural hearing loss. The processing is based on a modification of the chirp-z transform that allows for nonlinear sampling along an arbitrary contour of the z-plane. Although the theory allows the nonlinear sampling to be arbitrary, an example showing that it is appropriate for nonli... View full abstract»

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  • Using signal processing techniques for DNA sequence comparison

    Publication Year: 1989, Page(s):173 - 174
    Cited by:  Papers (10)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB)

    The most widely used algorithm for the comparison of two sequences of DNA are O(m×n) on the lengths, m and n, of the sequences been compared. The authors present a comparison algorithm that is O(nlog n) on the length, n, of the longer sequence. This algorithm uses techniques developed for rapid comparison of two discrete signals,... View full abstract»

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  • Simulated hearing loss as a baseline for the assessment of auditory function in cochlearly impaired listeners

    Publication Year: 1989, Page(s):19 - 20
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    An overview is presented of results obtained in listeners with real and simulated impairments. Spectral processing is assessed by psychoacoustical tuning curves and growth-of-masking functions; temporal processing is assessed by temporal integration and gap detection thresholds. When comparisons are made to normal listeners tested in the quiet, impaired listeners generally show deficits on all the... View full abstract»

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  • A programmable timing device for neurophysiological studies of the auditory system

    Publication Year: 1989, Page(s):193 - 194
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (156 KB)

    To study the effects of stimulus duration on neural responses, it is essential to be able to modify stimulus timing paradigms rapidly. A four-channel programmable timing device (PTD) has been designed to provide flexible and accurate data-acquisition timing protocols, PTD outputs are used to control data-acquisition and stimulus-generation peripherals. Four attributes of the timing protocol are pr... View full abstract»

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  • Measurement of turbulent flow in vascular grafts

    Publication Year: 1989, Page(s):85 - 86
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (136 KB)

    For a smooth-walled tube, the critical Reynolds number R c is primarily determined by the geometry of the inlet and is usually on the order of Rc=2000, although it has been measured as high as Rc=40000 in some highly refined systems. The effect of wall irregularities, such as in a fabric graft, is to lower Rc. The auth... View full abstract»

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  • Intraocular lens optical quality testing

    Publication Year: 1989, Page(s):47 - 48
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (88 KB)

    The possibility that problems relating to the optical quality of manufactured intraocular lenses (IOLs) may require regulatory attention is addressed. Based on the American National Standard for Ophthalmics-Intraocular Lenses-Optical and Physical Requirements (ANSI Standard Z80.7-1984), the US Food and Drug Administration (FDA) will soon be ready for conformance testing of IOLs. A description is g... View full abstract»

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  • Spectral characterization of the myoelectric signal in infants

    Publication Year: 1989, Page(s):155 - 156
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (124 KB)

    Myoelectric signal data were recorded from infants between the ages of 6 months and 2 years and processed to determine the spectral content of the signal. The protocol for obtaining the infant myoelectric signal and processing the resultant nonstationary data is described. The results indicate that the spectral content of the infant myoelectric signal does not differ significantly from the spectra... View full abstract»

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  • Technology and quantitative techniques for monitoring multi-faceted neonatal data

    Publication Year: 1989, Page(s):191 - 192
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (128 KB)

    A microprocessor-based system has been developed to evaluate the effects of environmental stimuli on infants in the neonatal intensive care unit. Physiological parameters, such as heart rate, respiration, blood pressure, and transcutaneous oxygen and CO2 levels are routinely monitored in the nursery by standard intensive care monitoring instruments. These outputs are digitized and recor... View full abstract»

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  • Semi-invasive fiber-optic tonometer

    Publication Year: 1989, Page(s):167 - 168
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB)

    A semi-invasive method for the instantaneous and continuous measurement of absolute blood pressure in small arteries is developed using the principle of arterial tonometry. This is accomplished with a miniature implantable fiber-optic sensor enclosed in an applanation ring and positioned around the artery. A reflective stainless-steel diagram (0.005 mm) bonded to a stainless-steel block is used to... View full abstract»

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  • Mean velocity measurements within a Penn State left ventricular assist device

    Publication Year: 1989, Page(s):83 - 84
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB)

    A laser Doppler anemometer (LDA) was used to measure two components of the mean velocity vectors at over 125 locations within a 70-cm3 plexiglas model of the Penn State left ventricular assist device (LVAD). The model ventricle was filled with a blood analog fluid and operated at normal physiological conditions. The probe volume was positioned at the strategically selected locations alo... View full abstract»

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  • Digital image enhancement for the visually-impaired: simulations and results

    Publication Year: 1989, Page(s):45 - 46
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB)

    The authors evaluate whether patients demonstrate improved face recognition when viewing enhanced images. Difficulty with face recognition is a frequent, early complaint of many patients with macular disease. Faces can be recognized when low-pass filtered to a large degree or high-pass filtered. To evaluate actual face recognition rather than the ability to discriminate among test faces, the autho... View full abstract»

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  • Nitroprusside abolishes increased arterial wave reflections from methoxamine-induced hypertension

    Publication Year: 1989, Page(s):131 - 132
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (116 KB)

    Afterload reduction has been considered to be of primary importance in the treatment of hypertensive patients. It has not been clear how the central aorta and the peripheral vasculature interact to bring this about. The authors examined this aspect in terms of wave reflections in open-chest anesthetized dogs. Results show that nitroprusside effectively reduced the increased wave reflection from hy... View full abstract»

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