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TitleCreatorDescriptionSubjectDate
51Acoustic droplet vaporization, cavitation, and therapeutic properties of copolymer-stabilized perfluorocarbon nanoemulsionsAcoustic droplet vaporization, cavitation, and therapeutic properties of copolymer-stabilized perfluorocarbon nanoemulsionsChristensen, Douglas A.Acoustic and therapeutic properties of Doxorubicin (DOX) and paclitaxel (PTX)-loaded perfluorocarbon nanoemulsions have been investigated in a mouse model of ovarian cancer. The nanoemulsions were stabilized by two biodegradable amphiphilic block copolymers that differed in the structure of the hydr...Cancer therapy; Targeted drug delivery; Nanobubbles; Ultrasound; Perfluoropentane2009
52Action potential classification with dual channel intrafascicular electrodesAction potential classification with dual channel intrafascicular electrodesHorch, Kenneth W.Using recordings of peripheral nerve activity made with carbon fiber intrafascicular electrodes, we compared the performance of three different recording techniques (single channel, differential, and dual channel) and four different unit classification methods (linear discriminant analysis, temp...Carbon fiber intrafascicular electrodes; Dual channel recording1994
53Plasma-etched polymer waveguides for intrachip optical interconnectsPlasma-etched polymer waveguides for intrachip optical interconnectsChristensen, Douglas A.Optical intrachip communication offers the potential advantages of high speed and lack of electrical interference. We report on progress made on an interconnect design using GaAs LEDs, polymer waveguides, and photodiodes in a silicon substrate. The polymer waveguides are fabricated in polyimide or p...Polymer waveguides; Intrachip interconnects; LEDs1998
54Problem and treatment of DC offsets in FDTD simulationsProblem and treatment of DC offsets in FDTD simulationsChristensen, Douglas A.; Furse, Cynthia M.This paper discusses the causes of and some solutions to the commonly observed problem of dc field offsets in finite-difference time-domain (FDTD) simulations. DC electric and magnetic field offsets are shown to be valid calculated responses of the modeled systems, resulting from interaction betwee...Finite-difference time-domain method; Direct current offsets; Waveforms2000-08
55General formulation for connecting sources and passive lumped-circuit elements across multiple 3-D FDTD cellsGeneral formulation for connecting sources and passive lumped-circuit elements across multiple 3-D FDTD cellsChristensen, Douglas A.A previous extension of the finite-difference time-domain (FDTD) method to include lumped-circuit elements is further extended to model lumped-element circuits connected across multiple FDTD cells. This formulation is needed to model many kinds of circuits, like those with a transistor or other ac...Finite-difference time-domain method; Lumped-element circuit; Dielectric; Microstrip1996-02
56Fiberoptic laser angioplasty probe with optical steerabilityFiberoptic laser angioplasty probe with optical steerabilityChristensen, Douglas A.; Vincent, G. MichaelWe have designed and bench tested an optically steerable fiberoptic probe for use in laser angioplasty. The unique feature of this design is the use of a gradient-index (GRIN) lens attached to the distal end of a seven-fiber bundle. By selecting which fiber of the bundle is illuminated by the source...Fiberoptic probe; GRIN lens; Steerability1990
57Finite-difference time-domain modeling and experimental characterization of planar waveguide fluorescence sensorsFinite-difference time-domain modeling and experimental characterization of planar waveguide fluorescence sensorsChristensen, Douglas A.The finite-difference time-domain method (FDTD) is a powerful numerical technique for solving Maxwell's equations in a discretized space and time grid. Its applications have up to now been in the analysis of electrically large structures in the microwave domain, and the scope of investigations has b...Finite-difference time-domain method; Planar waveguide1992
58Biosensor development at the University of UtahBiosensor development at the University of UtahChristensen, Douglas A.Interest in biosensors has increased rapidly in the past few years due to the many potential advantages of these devices, such as small size, speed of response, and specificity 111. The term "biosensor" in the broad sense describes any device or apparatus which detects biological signals for the pu...Silicon retina; Photosensing array; CHEMFET; Fluorescence lmmunosensor; Planar waveguide1994-07
59Bringing an integrative modeling experience to a freshman biomedical engineering courseBringing an integrative modeling experience to a freshman biomedical engineering courseChristensen, Douglas A.As an integrating lab experience in our Fundamentals of Bioengineering freshman course, we have included a Major Project that ties together many of the principles of biomechanics and bioelectricity covered in the lecture. It uses the human systemic cardiovascular system as a model. During the first...Matlab2004
60Evanescent coupling in a waveguide fluoroimmunosensorEvanescent coupling in a waveguide fluoroimmunosensorChristensen, Douglas A.; Herron, James N.A key factor in the analysis of evanescently-coupled optical sensors, such as the planar waveguide immunosensor analyzed here, is the efficiency of coupling between the optical waveguide modes and the fluorescent sources located on the surface of the waveguide. This is an important parameter in dete...Evanescent coupling; Waveguide; Fluoroimmunosensor1992
61Experience with the first three years of an accelerated dual-degree program in biomedical engineeringExperience with the first three years of an accelerated dual-degree program in biomedical engineeringChristensen, Douglas A.; Horch, Kenneth W.Our Department of Bioengineering has instituted a pilot program aimed at helping a select group of highly qualified students obtain both bachelor's and master's degrees in an accelerated timeframe-approximately four years from the beginning of their university studies. A key element of this progra...Accelerated; Dual-degrees; Education2004
62Differential activation of nerve fibers with magnetic stimulation in humansDifferential activation of nerve fibers with magnetic stimulation in humansHorch, Kenneth W.Earlier observations in our lab had indicated that large, time-varying magnetic fields could elicit action potentials that travel in only one direction in at least some of the myelinated axons in peripheral nerves. The objective of this study was to collect quantitative evidence for magnetically in...Magnetic stimulation; Peripheral nerve; Electromyographic potential; Somatosensory potential2006
63Accelerated 4-year bachelors/masters degree program in biomedical engineeringAccelerated 4-year bachelors/masters degree program in biomedical engineeringHorch, Kenneth W.; Christensen, Douglas A.In response to the need for providing advanced engineering education in a shorter time period than is currently possible by traditional curricula, we have created an Accelerated Dual Degree program in biomedical engineering. The purpose of this pilot program is to attract the brightest students, g...Accelerated; Dual-degrees; Education2002
64Accelerated 4-year bachelors/masters degree program in biomedical engineeringAccelerated 4-year bachelors/masters degree program in biomedical engineeringHorch, Kenneth W.; Christensen, Douglas A.In response to the need for providing advanced engineering education in a shorter time period than is currently possible by traditional curricula, we have created an Accelerated Dual Degree program in biomedical engineering. The purpose of this pilot program is to attract the brightest students, g...Accelerated dual-degree program2002
65Accelerated dual-degree BS/MS program - experience with the first three yearsAccelerated dual-degree BS/MS program - experience with the first three yearsChristensen, Douglas A.; Horch, Kenneth W.We have initiated a pilot program that accelerates the studies of a small group of highly qualified students early in their college careers and allows them to earn both a bachelor's degree and a master's degree in about four years after starting college. It does this by introducing them early to res...Accelerated dual-degree program2004
66Simulation of a phosphene field based visual prosthesisSimulation of a phosphene field based visual prosthesisHorch, Kenneth W.; Normann, Richard A.A visual prosthesis for the blind based upon electrical stimulation of the visual cortex requires the development of an array of electrodes. To establish design specifications for such an electrode array, we have conducted psychophysical experiments with normally sighted subjects wearing a portable...Visual prosthesis; Phosphene simulator1990
67Neural signal for skin indentation depth. I. Changing indentationsNeural signal for skin indentation depth. I. Changing indentationsHorch, Kenneth W.; Tuckett, Robert P.; Burgess, Paul RichardPsychophysical 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
68Neural signal for skin indentation depth. II. Steady indentationsNeural signal for skin indentation depth. II. Steady indentationsHorch, Kenneth W.; Tuckett, Robert P.; Burgess, Paul RichardThe 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
69Neural signal for the intensity of a tactile stimulusNeural signal for the intensity of a tactile stimulusHorch, Kenneth W.; Tuckett, Robert P.; Burgess, Paul RichardThe 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
70Noble metal penetrating cortical stimulating electrode array: preliminary resultsNoble metal penetrating cortical stimulating electrode array: preliminary resultsHorch, Kenneth W.; Normann, Richard A.Electrical stimulation of the visual cortex causes subjects to see spots of light (phosphenes) in their visual fields. We have developed arrays of penetrating electrodes which may from the basis of a visual prosthesis centered around electrical stimulation of the visual cortex. These arrays have bee...Visual prosthesis1988
71Optical immunoassay systems based upon evanescent wave interactionsOptical immunoassay systems based upon evanescent wave interactionsChristensen, Douglas A.; Herron, James N.Immunoassays based upon evanescent wave interactions are finding increased biosensing application. In these devices, the evanescent tail associated with total internal reflection of an incident beam at the substrate/solution interface provides sensitivity for surface-bound proteins over bulk molec...Diagnostics; Evanescence; Planar waveguides; Human chorionic gonadotropin (hCG)1996
72Identification of single units in multi-unit recordings from peripheral nervesIdentification of single units in multi-unit recordings from peripheral nervesHorch, Kenneth W.We are developing a computer-based method for identifying individual action potentials in multi-unit peripheral nerve recordings. Threshold level, sinusoidal stimuli are used to elicit phase-locked activity from single units. These action potentials are digitized, and a template is constructed usin...Peripheral nerve; Neural recordings; Cutaneous mechanoreceptors1988
73Ontogeny of diving and feeding behavior in juvenile seaturtles: Leatherback Seaturtles (Dermochelys coriacea L) and Green Seaturtles (Chelonia mydas L) in the Florida CurrentOntogeny of diving and feeding behavior in juvenile seaturtles: Leatherback Seaturtles (Dermochelys coriacea L) and Green Seaturtles (Chelonia mydas L) in the Florida CurrentHorch, Kenneth W.We compared activity, diving behavior and response to prey by Dermochelys coriacea and Chelonia mydas during their first 8-10 weeks of development.We reared juveniles in the laboratory and, at two-week intervals, released them in the ocean for a brief trial. Each turtle towed a device used to measur...Hatchlings; Posthatchling; Habitats2004
74Synaptic inputs to physiologically defined turtle retinal ganglion cellsSynaptic inputs to physiologically defined turtle retinal ganglion cellsNormann, Richard A.; Muller, Jay F.; Kolb, HelgaTwo physiologically distinct, HRP-marked turtle retinal ganglion cells were examined for their morphology, GABAergic, glycinergic, and bipolar cell synaptic inputs, using electron-microscopic autoradiography and postembedding immunocytochemistry. One cell was a color-opponent, transient ON/OFF gangl...Turtles; Neural Pathways; Synapes; Retinal Ganglion Cells1991
75Study of printed spiral coils for neuroprosthetic transcranial telemetry applicationsStudy of printed spiral coils for neuroprosthetic transcranial telemetry applicationsNormann, Richard A.; Shah, Maulik R.We have explored the use of printed spiral coils (PSC's) for neuroprosthetic transcranial telemetry applications. We fabricated two-dimensional PSC's on a thin (25 microns) polyimide substrate using copper (35 microns) as a conducting material. All the coils had a fixed inner diameter of 1.0 cm. We ...Blindness; Neuroprosthesis; Transcranial Telemetry System; Prosthesis Design1998
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