51 - 75 of 128
Number of results to display per page
CreatorTitleDescriptionSubjectDate
51 Christensen, Douglas A.; Andrade, Joseph D.Improved sensitivity in ellipsometry of thin biochemical films by employing sublayersEllipsometry is widely used for investigating the optical properties of thin films on planar substrates, including films of adsorbed proteins or polymers. The average thickness and effective refractive index of the adsorbed layer are calculated by measuring the A and ¥ ellipsometry parameters. Unfo...Biochemical films; SiO2 sublayer1990
52 Christensen, Douglas A.Influence of temperature probe sheathing materials during ultrasonic heatingThe influence of sheathing materials upon temperature probes used during the monitoring of ultrasonic heating was measured. The measurements show that the sheathing can be heated in a manner not representative of the temperature rise occurring in the surrounding material, altering the probe reading...Ultrasonic hyperthermia; Sheathing; Phantom tests; Teflon1986-05
53 Horch, Kenneth W.Information contrained in sensory nerve recordings made with intrafascicular electrodesMultiunit recordings were made in anesthetized cats with chronically implanted intrafascicular electrodes over a period of six months. Neural signals recorded with these electrodes consisted of activity in sensory fibers innervating a variety of cutaneous mechanoreceptors. Mechanical stimuli wer...Intrafascicular electrodes; Functional electrical stimulation (FES); Closed-loop control1991
54 Horch, Kenneth W.Information extraction from peripheral nervesThis work is directed toward providing better rehabilitation for people suffering from somatosensory loss and paralysis due to spinal cord injury, head trauma, or stroke. The goal of this project is to demonstrate that information suitable for controlling prosthetic devices, modulating functional el...Peripheral nerve; Neural recordings; Intrafascicular electrodes1991
55 Christensen, Douglas A.Interface of forest and agriculture in nonpoint pollution controlManagement practices of agriculture, including conservation and tillage options, recently have received a great deal of attention with respect to their impact upon the environment. Research efforts have focused both on the direct impacts of reduced on-site productivity resulting from the erosion of ...Suspended sediment; Channel erosion; Silviculture1983
56 Horch, Kenneth W.Intrafascicular electrodes for nerve stimulationWe have designed a new type of intrafascicular, implanted electrode for stimulating peripheral nerves to elicit muscle contraction. The electrode requires low current to stimulate the nerve fibers, provides a fine control of muscular force, and causes little or no tissue reaction. it is of potential...Intrafascicular electrodes; Peripheral nerve; Neural recordings1988
57 Horch, Kenneth W.Intraspinal microstimulation using cylindrical multielectrodesA cylindrical multielectrode system specifically designed for intraspinal microstimulation was mechanically and electrically evaluated in the ventral horn of the feline lumbo-sacral spinal cord. Electrode insertions proved to be straight as evaluated from radiographs. Impedances were measured in s...Cylindrical multielectrode; Microstimulation; Neural prosthesis; Current distance constants; Electrode array; Spinal cord stimulation2006-02
58 Christensen, Douglas A.Introduction to biomedical engineering: biomechanics and bioelectricity - part IIntended as an introduction to the field of biomedical engineering, this book covers the topics of biomechanics (Part I) and bioelectricity (Part II). Each chapter emphasizes a fundamental principle or law, such as Darcy's Law, Poiseuille's Law, Hooke's Law, Starling's law, levers and work in the a...Biological membranes; Poiseuille's law; Hooke's law; Starling's law of the heart; Matlab2009
59 Christensen, Douglas A.Introduction to biomedical engineering: biomechanics and bioelectricity - part IIIntended as an introduction to the field of biomedical engineering, this book covers the topics of biomechanics (Part I) and bioelectricity (Part II). Each chapter emphasizes a fundamental principle or law, such as Darcy's Law, Poiseuille's Law, Hooke's Law, Starling's Law, levers and work in the...Bioelectricity; Kirchhoff's voltage law; Kirchhoff's current law; Coulomb's law; Thevenin equivalent circuits; Nernst potential; Matlab2009
60 Christensen, Douglas A.Laser diode coherence length variation with drive current: a tool for dispersion measurementsA visible light (670nm) laser diode was used as a variable coherence length source to measure dispersion characteristics in single-mode fibers. The diode's spectral width, measured against increasing drive current, was found to change from about 16 nanometers to less than 0.2 nanometer. The corresp...Laser diode; Fiber interferometry1992
61 Normann, Richard A.; Branner, AlmutLong-term stimulation and recording with a penetrating microelectrode array in cat sciatic nerveWe studied the consequences of long-term implantation of a penetrating microelectrode array in peripheral nerve over the time course of 4-6 mo. Electrode arrays without lead wires were implanted to test the ability of different containment systems to protect the array and nerve during contractions o...Cats; Microelectrodes; Prosthesis Implantation; Sciatic Nerve2004
62 Horch, Kenneth W.Mechanical testing of metallic and polymeric intrafascicular electrodesWe are exploring alternatives to Pt/Ir wire for constructing ultra-flexible neural intrafascicular electrodes suitable for chronic implantation. In this study we measured the flexural properties of several kinds of fine metal wires and conducting polymer fibers. The fibers were made either of in...Intrafascicular electrodes; Polymer fibers1994
63 Horch, Kenneth W.Microfabricated cylindrical multielectrodes for neural stimulationThe effects of spinal cord injuries are likely to be ameliorated with the help of functional electrical stimulation of the spinal cord, a technique that may benefit from a new style of electrode: the cylindrical multielectrode. This paper describes the specifications for, fabrication techniques for...Cylindrical multielectrode; Depth electrodes; Impedance testing; Microelectromechanical systems (MEMS); Microstimulation; Impedance testing; Neural prosthesis2006-02
64 Jenson, Justin Michael; Bock, Susan C.Mitigating spinal cord injuryHow would your life change if you became one of the 15,000 Americans to suffer a spinal cord injury this year? Trauma to the spinal cord causes immediate loss of function below the level of the injury. Then, in the hours and days after the accident, the body's secondary injury response may extend ...Trapeze Interactive Poster2010-03-15
65 Normann, Richard A.; Horch, Kenneth W.; Cha, KichulMobility performance with a pixelized vision systemA visual prosthesis, based on electrical stimulation of the visual cortex, has been suggested as a means for partially restoring functional vision in the blind. The prosthesis would create a pixelized visual sense consisting of punctate spots of light (phosphenes). The present study investigated the...Visual Prosthesis; Mobility; Phosphene Simulator1992
66 Christensen, Douglas A.Modeling sources in the FDTD formulation and their use in quantifying source and boundary condition errorsThe modeling of voltage and current sources as either added or replaced sources in FDTD simulations is described and their differences discussed in terms of a transmission line analogy. An infinitesimal current element (ICE) is used to illustrate the validation of added source modeling and to study...Finite-difference time-domain method; Infinitesimal current element1995-04
67 Christensen, Douglas A.Multiple sensor optical thermometry system for application in clinical hyperthermiaThe thermometry system described is based upon the temperature dependence of the band edge absorption of infrared light in GaAs crystal. The design of the thermometry was completed, and the system was subjected to an extensive evaluation, including testing with tissue phantoms and microwave applic...Thermometry; Hyperthermia applicator; Phantom tests1984-01
68 Horch, Kenneth W.Muscle recruitment through electrical stimulation of the lumbo-sacral spinal cordThe goal of this study was to determine the feasibility of producing graded muscle contraction in individual muscles or muscle groups by electrically stimulating motor neurons in the lumbo-sacral spinal cord. Recruitment curves were obtained for quadriceps, tibialis anterior and triceps surae/pl...Functional neuromuscular stimulation (FNS); Motor pools, Muscle recruitment, Spinal cord stimulation2000
69 Horch, Kenneth W.Muscle recruitment with intrafascicular electrodesWe have studied muscle recruitment with Tefloninsulated, 25 pm diameter, Pt-Ir intrafasicular electrodes implanted in nerves innervating the gastrocnemius and soleus muscles of cats. The purpose of this study was to measure the performance of these bipolar electrodes, which had been designed to...Functional neuromuscular stimulation (FNS); Intrafascicular electrode1991
70 Normann, Richard A.; Maynard, Edwin M.Neural interface for a cortical vision prosthesisThe development of a cortically based vision prosthesis has been hampered by a lack of basic experiments on phosphene psychophysics. This basic research has been hampered by the lack of a means to safely stimulate large numbers of cortical neurons. Recently, a number of laboratories have developed a...Neuroprosthetics; Artificial Vision; Electrode Arrays; Multielectrode Recordings; Biocompatibility1999
71 Normann, Richard A.; Kolb, HelgaNeural organization of the retina of the turtle Mauremys caspica: a light microscope and Golgi studyThe organization of the retina of the turtle species Mauremys caspica, found in fresh water ponds of Israel, has been examined by light microscopical techniques including examination of fresh wholemount retina, one micron blue-stained vertical sections and Golgi-stained material. The anatomical find...Turtle Retina; Photoreceptors; Golgi Technique; Amarcine Cells1988
72 Horch, Kenneth W.; Tuckett, Robert P.; Burgess, Paul RichardNeural signal for skin indentation depth. I. Changing indentationsPsychophysical tests on human subjects showed that judgments of skin indentation depth made when the fingertip was indented at rates from 0.2 to 16 mm/set were quite insensitive to changes in indentation velocity. Similar results were obtained on the forearm at indentation velocities of 0.4 to 16...Skin; Indentation; Nerve impulses1983
73 Horch, Kenneth W.; Tuckett, Robert P.; Burgess, Paul RichardNeural signal for skin indentation depth. II. Steady indentationsThe glabrous skin of the monkey's hand was stimulated with a waveform that indented the skin at a rate of 0.4 mm/set, held the skin steadily or nearly steadily indented for 12 set or longer, and then retracted back to the starting position. Recordings were made of activity in single afferent fibe...Skin; Indentation; Nerve impulses1983
74 Horch, Kenneth W.; Tuckett, Robert P.; Burgess, Paul RichardNeural signal for the intensity of a tactile stimulusThe effect of indenting the skin at different rates on the perceived intensity of the stimulus was studied by indenting the skin of the fingertip with two triangular waveforms, given as a pair. The subjects were asked to judge which member of the pair was more intense. Perceived intensity was foun...Skin; Indentation; Nerve impulses1984
75 Gerig, GuidoNeuro imaging research lab2012
51 - 75 of 128