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CreatorTitleDescriptionSubjectDate
51 Horch, Kenneth W.Unit analysis in composite neural recordingsWe have used threshold level, sinusoidal stimuli to selectively elicit phase-locked activity from cutaneous mechanoreceptors, for the purpose of evaluating single unit activity in multi-unit peripheral nerve recordings. Each receptor is characterized by its response to a range of mechanical stimuli ...Neural recordings; Nerve fibers; Cutaneous mechanoreceptors1989
52 Horch, Kenneth W.Towards a neuroprosthetic armEvidence indicates that user acceptance of modern artificial limbs by amputees would be significantly enhanced by a system that provides appropriate, graded, distally referred sensations of touch and joint movement, and that the functionality of limb prostheses would be improved by a more natural co...Neuroprosthetic arm; Peripheral nerve; Neuroprosthetics; Amputee2006
53 Gesteland, Raymond F.Cell-free synthesis of herpes simplex virus proteinsPolyribosomes isolated from herpes simplex virus type I (HSV-1)-infected cells have been used to program a eucaryotic cell-free translation system. At least 10 HSV-specific polypeptides, with apparent molecular weights of 25,000 to 160,000, are synthesized by wild-type HSV-infected polyribosomes. Po...Viral Proteins; Herpes Simplex; Peptide Biosynthesis; Thymidine Kinase1977
54 Christensen, Douglas A.FDTD modeling in the design of optical chemical sensor structuresThe finite-difference time-domain method (FDTD) is a numerical technique for solving Maxwell's equations in a discretized space and time frame. It has been used extensively in the analysis of electrically large structures in the microwave domain, but has only recently been applied to optical proble...Finite-difference time-domain method; Immunochemical fluorosensors; Planar waveguides1991
55 Christensen, Douglas A.Dispersion effects in fiber optic interferometryAn extended analysis of the effects of uncompensated fiber dispersion on the fringe visibility of a fiber optic interferometer is developed, with particular emphasis on stellar interferometry. Both material and waveguide dispersion for single-mode, polarization-preserving fibers are considered. It...Stellar interferometry; Fiber optics; Statistical optics1997
56 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
57 Horch, Kenneth W.; Normann, Richard A.Simulation of a phosphene field based visual prosthesisA 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
58 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
59 Vardhan, AvantikaCharacterizing growth patterns in longitudinal MRI using image contrastUnderstanding the growth patterns of the early brain is crucial to the study of neuro-development. In the early stages of brain growth, a rapid sequence of biophysical and chemical processes take place. A crucial component of these processes, known as myelination, consists of the formation of a myel...2014-01-01
60 Normann, Richard A.; Clark, Gregory A.; McDonnall, DanielSelective motor unit recruitment via intrafascicular multielectrode stimulationRecruitment of force via independent asynchronous firing of large numbers of motor units produces the grace and endurance of physiological motion. We have investigated the possibility of reproducing this physiological recruitment strategy by determining the selectivity of access to large numbers of ...Funtional Neuromuscular Stimulation; Microelectrode Array; Neuroprosthesis; Intrafascicular Multielectrode Stimulation; Cats2004
61 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
62 Christensen, Douglas A.Using the cardiovascular system to illustrate fundamental laws and principles in a freshman courseOur Fundamentals of Bioengineering I course is organized around key physical and engineering laws and principles. A semester-long Major Project is assigned which integrates many of these principles by modeling the human systemic cardiovascular system, using both Matlab computer analysis and assembly...Matlab2002
63 Horch, Kenneth W.Are the extrinsic muscles better suited for signaling joint angles or finger tip location?We used a biomechanical model of the human long finger to determine whether the extrinsic muscles are better suited for estimating the finger's joint angles or for estimating location of the finger tip. We found that two of the extrinsic muscles together could provide information sufficient to direc...Extrinsic muscles; Metacarpophalangeal joint; Biomechanical models1997
64 Horch, Kenneth W.Stability of chronic intrafascicular electrode recordingsWe have implanted intrafascicular electrodes in peripheral nerves of cats and have recorded neural activity from a small population of nerve fibers for as long as six months, suggesting that these electrodes can be used on a chronic basis to acquire information about limb position, muscle force and ...Intrafascicular electrodes; Electrode recordings1989
65 Gesteland, Raymond F.; Atkins, John F.; Tuohy, Therese M.Uninterrupted translation through putative 12-nucleotide coding gap in sequence of carA: business as usualPrevious work of others reported an untranslated stretch of 12 nucleotides in the 5' coding sequence of carA from Pseudomonas aeruginosa. However, N-terminal protein sequencing of carA-lacZ translational fusions shows that these 12 nucleotides are normally translated in a continuous triplet manner, ...Base Sequence; Protein Biosynthesis; Sequence Deletion1994
66 Horch, Kenneth W.Selective activation of functional muscle groups through stimulation of spinal motor poolsA microelectrode was used to stimulate motor neurons in the lumbo-sacral spinal cord of adult cats. Consistent with spinal cord anatomical studies, we found that the motor neurons responsible for activation of individual muscle groups are situated together in specific areas of the cord, forming mot...Spinal motor pools1993
67 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
68 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
69 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
70 Gesteland, Raymond F.Translation of Rl7 RNA fragmentsExamination of the events during infection of cells by RNA phages reveals phemonomena that are surprisingly complex for a virus that has only enough information to code for three to four proteins. The coat protein is synthesized at a rapid rate through most of the infectious cycle making it the pre...Electrophoresis; RNA, Messenger; Peptide Biosynthesis; Kinetics1969
71 Horch, Kenneth W.; Normann, Richard A.Noble metal penetrating cortical stimulating electrode array: preliminary resultsElectrical 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
72 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
73 Gesteland, Raymond F.; Atkins, John F.; Baranov, Pavel V.P-site tRNA is a crucial initiator of ribosomal frameshiftingThe expression of some genes requires a high proportion of ribosomes to shift at a specific site into one of the two alternative frames. This utilized frameshifting provides a unique tool for studying reading frame control. Peptidyl-tRNA slippage has been invoked to explain many cases of programmed ...Translation; Recoding; Kinetic Model; Frameshifting; Ribosome2004
74 Christensen, Douglas A.; Herron, James N.Comparison of robust coupling techniques for planar waveguide immunosensorsWe have analyzed and fabricated two different coupling schemes to meet the requirements for a convenient means of coupling into a planar waveguide immunosensor that is relatively insensitive to beam alignment. These are the "launch" coupler and the grating coupler. Each possesses advantages and dis...Planar waveguide immunosensors; Fluorescence; Launch coupler; Grating coupler1993
75 Horch, Kenneth W.Differential activation of nerve fibers with magnetic stimulation in humansEarlier 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
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