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https://www.readbyqxmd.com/read/28463302/co-axis-digital-holography-based-on-sinusoidal-phase-modulation-using-generalized-lock-in-detection
#1
Yunlong Zhu, Julien Vaillant, Manuel François, Guillaume Montay, Aurélien Bruyant
Sinusoidal phase modulating (SPM) interferometers are used to precisely measure complex light fields with simple interferometric setups. Recently, a generalized lock-in technique has been proposed for optimizing the signal extraction in phase-modulated interferometers. This article shows its applicability in digital holography as well as digital holographic interferometry. A compact homemade setup based on the Michelson interferometer was used to observe the scattering sample surface with a spatial resolution of 32 LP/mm; out-of-plane rotation was measured with a theoretical detection limit of 0...
May 1, 2017: Applied Optics
https://www.readbyqxmd.com/read/28457586/adaptation-of-the-vertical-vestibulo-ocular-reflex-in-cats-during-low-frequency-vertical-rotation
#2
Hiroaki Fushiki, Motoyoshi Maruyama, Hideo Shojaku
OBJECTIVE: We examined plastic changes in the vestibulo-ocular reflex (VOR) during low-frequency vertical head rotation, a condition under which otolith inputs from the vestibular system are essential for VOR generation. METHODS: For adaptive conditioning of the vertical VOR, 0.02Hz sinusoidal pitch rotation for one hour about the earth's horizontal axis was synchronized with out-of-phase vertical visual stimulation from a random dot pattern. RESULTS: A vertical VOR was well evoked when the upright animal rotated around the earth-horizontal axis (EHA) at low frequency due to the changing gravity stimulus and dynamic stimulation of the otoliths...
April 27, 2017: Auris, Nasus, Larynx
https://www.readbyqxmd.com/read/28455665/cross-coupling-vestibular-stimulation-motion-sickness-and-the-vestibulo-sympathetic-reflex
#3
Fausto Romano, Nicoletta Caramia, Dominik Straumann, Eugene Nalivaiko, Giovanni Bertolini
Motion sickness is associated with a variety of autonomic symptoms, presumably due to proximity or functional interconnectivity between the autonomic centers in the brainstem and the vestibular system. A direct influence of the vestibular system on cardiovascular variables, defined as the vestibulo-sympathetic reflex, has been reported previously. Our aim was to investigate the sudomotor components of the autonomic responses associated with motion sickness during passive cross-coupling stimulation ("roll while rotating")...
April 28, 2017: Journal of Neurology
https://www.readbyqxmd.com/read/28417834/adaptive-changes-in-the-perception-of-fast-and-slow-movement-at-different-head-positions
#4
Roberto Panichi, Chiara Occhigrossi, Aldo Ferraresi, Mario Faralli, Marco Lucertini, Vito E Pettorossi
BACKGROUND: This paper examines the subjective sense of orientation during asymmetric body rotations in normal subjects. METHODS: Self-motion perception was investigated in 10 healthy individuals during asymmetric whole-body rotation with different head orientations. Both on-vertical axis and off-vertical axis rotations were employed. Subjects tracked a remembered earth-fixed visual target while rotating in the dark for four cycles of asymmetric rotation (two half-sinusoidal cycles of the same amplitude, but of different duration)...
May 1, 2017: Aerospace Medicine and Human Performance
https://www.readbyqxmd.com/read/28396602/nanoplasmonic-upconverting-nanoparticles-as-orientation-sensors-for-single-particle-microscopy
#5
Kory K Green, Janina Wirth, Shuang F Lim
We showed that the anisotropic disk shape of nanoplasmonic upconverting nanoparticles (NP-UCNPs) creates changes in fluorescence intensity during rotational motion. We determined the orientation by a three-fold change in fluorescence intensity. We further found that the luminescence intensity was strongly dependent on the particle orientation and on polarization of the excitation light. The luminescence intensity showed a three-fold difference between flat and on-edge orientations. The intensity also varied sinusoidally with the polarization of the incident light, with an Imax/Imin ratio of up to 2...
April 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28291198/-clinical-results-of-aphakia-correction-with-multifocal-intraocular-lenses
#6
G V Voronin, V R Mamikonyan, V M Sheludchenko, M N Narbut
AIM: to assess visual functions and ergonomics after bilateral versus unilateral implantation of Lentis Comfort LS-313 MF15 multifocal intraocular lenses (MIOL) in aphakic eyes. MATERIAL AND METHODS: A total of 20 patients with М LENTIS LS-313 MF15 MIOLs were followed up. Group 1 consisted of 12 patients after bilateral symmetric implantation, group 2 - of 8 patients after unilateral procedure. The following parameters were examined: uncorrected binocular visual acuity at far, near, and intermediate distances under photopic and mesopic conditions, the range of pseudoaccommodation, spatial contrast sensitivity to achromatic sinusoidal gratings, lens stability with account to its optical design, and patient satisfaction with the resultant vision...
2017: Vestnik Oftalmologii
https://www.readbyqxmd.com/read/28269379/energy-harvesting-from-human-walking-to-power-biomedical-devices-using-oscillating-generation
#7
Jose A Montoya, Dulce M Mariscal, Edwar Romero
This work summarizes the energy generation limits from walking employing a pendulum-based generation system. Self-winding wristwatches have exploited successfully this energy input technique for decades. Pendulum-based planar devices use the rotation to produce energy for inertial generators. Then the oscillations of body motion during locomotion present an opportunity to extract kinetic energy from planar generators. The sinusoidal motion of the center of gravity of the body, on the sagittal and frontal planes, and the limbs swinging are compliant with oscillating devices...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28249502/a-novel-cmos-transducer-for-giant-magnetoresistance-sensors
#8
Van Su Luong, Chih-Cheng Lu, Jing-Wen Yang, Jen-Tzong Jeng
In this work, an ASIC (application specific integrated circuits) transducer circuit for field modulated giant magnetoresistance (GMR) sensors was designed and fabricated using a 0.18-μm CMOS process. The transducer circuits consist of a frequency divider, a digital phase shifter, an instrument amplifier, and an analog mixer. These comprise a mix of analog and digital circuit techniques. The compact chip size of 1.5 mm × 1.5 mm for both analog and digital parts was achieved using the TSMC18 1P6M (1-polysilicon 6-metal) process design kit, and the characteristics of the system were simulated using an HSpice simulator...
February 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28227622/energy-harvesting-from-human-walking-to-power-biomedical-devices-using-oscillating-generation
#9
Jose A Montoya, Dulce M Mariscal, Edwar Romero, Jose A Montoya, Dulce M Mariscal, Edwar Romero, Dulce M Mariscal, Jose A Montoya, Edwar Romero
This work summarizes the energy generation limits from walking employing a pendulum-based generation system. Self-winding wristwatches have exploited successfully this energy input technique for decades. Pendulum-based planar devices use the rotation to produce energy for inertial generators. Then the oscillations of body motion during locomotion present an opportunity to extract kinetic energy from planar generators. The sinusoidal motion of the center of gravity of the body, on the sagittal and frontal planes, and the limbs swinging are compliant with oscillating devices...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28190505/thoracolumbar-movement-in-sound-horses-trotting-in-straight-lines-in-hand-and-on-the-lunge-and-the-relationship-with-hind-limb-symmetry-or-asymmetry
#10
L Greve, T Pfau, S Dyson
Equine movement symmetry is changed when turning, which may induce alterations in thoracolumbosacral kinematics; however, this has not previously been investigated. Our objectives were to document thoracolumbar movement in subjectively sound horses comparing straight lines with circles on both reins and to relate these observations to the objectively determined symmetry/asymmetry of hindlimb gait. Fourteen non-lame horses were assessed prospectively in a non-random, cross-sectional survey. The horses were trotted in straight lines and lunged on both reins and inertial sensor data collected at landmarks: withers, T13 and T18, L3, tubera sacrale, and left and right tubera coxae...
February 2017: Veterinary Journal
https://www.readbyqxmd.com/read/28176802/ocular-reflex-phase-during-off-vertical-axis-rotation-in-humans-is-modified-by-head-turn-on-trunk-position
#11
Samantha B Douglas, Gilles Clément, Pierre Denise, Scott J Wood
Constant velocity Off-Vertical Axis Rotation (OVAR) imposes a continuously varying orientation of the head and body relative to gravity, which generates a modulation of horizontal (conjugate and vergence), vertical, and torsional eye movements. We introduced the head-turn-on-trunk paradigm during OVAR to examine the extent to whether the modulation of these ocular reflexes is mediated by graviceptors in the head, i.e., otoliths, versus other body graviceptors. Ten human subjects were rotated in darkness about their longitudinal axis 20° off-vertical at a constant velocity of 45 and 180°/s, corresponding to 0...
February 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28125681/accumulation-of-inertial-sensory-information-in-the-perception-of-whole-body-yaw-rotation
#12
Alessandro Nesti, Ksander de Winkel, Heinrich H Bülthoff
While moving through the environment, our central nervous system accumulates sensory information over time to provide an estimate of our self-motion, allowing for completing crucial tasks such as maintaining balance. However, little is known on how the duration of the motion stimuli influences our performances in a self-motion discrimination task. Here we study the human ability to discriminate intensities of sinusoidal (0.5 Hz) self-rotations around the vertical axis (yaw) for four different stimulus durations (1, 2, 3 and 5 s) in darkness...
2017: PloS One
https://www.readbyqxmd.com/read/28077670/the-mammalian-efferent-vestibular-system-plays-a-crucial-role-in-vestibulo-ocular-reflex-compensation-after-unilateral-labyrinthectomy
#13
Patrick P Hübner, Serajul I Khan, Americo A Migliaccio
The α9-nicotinic acetylcholine receptor (α9-nAChR) subunit is expressed in the vestibular and auditory periphery, and its loss of function could compromise peripheral input from the predominantly cholinergic efferent vestibular system (EVS). A recent study has shown that α9-nAChRs play an important role in short-term vestibulo-ocular reflex (VOR) adaptation. We hypothesize that α9-nAChRs could also be important for other forms of vestibular plasticity, such as that needed for VOR recovery after vestibular organ injury...
April 1, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28063365/aging-reduces-the-high-frequency-and-short-term-adaptation-of-the-vestibulo-ocular-reflex-in-mice
#14
Serajul I Khan, Patrick P Hübner, Alan M Brichta, Doug W Smith, Americo A Migliaccio
Prevailing evidence indicates a relatively late life decline in human vestibulo-ocular reflex (VOR) function. Although mice are commonly used in mechanistic studies of vestibular function, it remains unclear whether aging produces a corresponding decline in VOR function in mice. We sought to determine how the baseline VOR and its short-term adaptation were affected by aging. We tested 8 young (3-month old) and 8 aged (30-month old-equivalent to a ∼80-year old human) C57BL/6 mice. We measured their VOR response to whole-body static tilts and during 0...
March 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28047059/th-cd-207a-06-optimizing-four-dimensional-digital-tomosynthesis-acquisition-based-on-respiratory-guidance
#15
D Kim, S Lee, S Kim, S Kang, T Kim, K Kim, M Cho, D Shin, Y Noh, T Suh
PURPOSE: Patient breathing-related sorting method of projections in 4D digital tomosythesis (DTS) can be suffered from severe artifacts due to non-uniform angle distribution of projections and noncoplanar reconstructed images for each phase. In this study, we propose a method for optimally acquiring projection images in 4D DTS. METHODS: In this method every pair of projections at x-ray tube's gantry angles symmetrical with respect to the center of the range of gantry rotation is obtained at the same respiration amplitude...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/27903636/spatiotopic-coding-during-dynamic-head-tilt
#16
Kyriaki Mikellidou, Marco Turi, David C Burr
Humans maintain a stable representation of the visual world effortlessly, despite constant movements of the eyes, head, and body, across multiple planes. Whereas visual stability in the face of saccadic eye movements has been intensely researched, fewer studies have investigated retinal image transformations induced by head movements, especially in the frontal plane. Unlike head rotations in the horizontal and sagittal planes, tilting the head in the frontal plane is only partially counteracted by torsional eye movements and consequently induces a distortion of the retinal image to which we seem to be completely oblivious...
February 1, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/27830658/nematic-liquid-crystals-on-sinusoidal-channels-the-zigzag-instability
#17
Nuno M Silvestre, Jose M Romero-Enrique, Margarida M Telo da Gama
Substrates which are chemically or topographically patterned induce a variety of liquid crystal textures. The response of the liquid crystal to competing surface orientations, typical of patterned substrates, is determined by the anisotropy of the elastic constants and the interplay of the relevant lengths scales, such as the correlation length and the surface geometrical parameters. Transitions between different textures, usually with different symmetries, may occur under a wide range of conditions. We use the Landau-de Gennes free energy to investigate the texture of nematics in sinusoidal channels with parallel anchoring bounded by nematic-air interfaces that favour perpendicular (hometropic) anchoring...
November 10, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/27782689/online-4d-ultrasound-guidance-for-real-time-motion-compensation-by-mlc-tracking
#18
Svenja Ipsen, Ralf Bruder, Rick O'Brien, Paul J Keall, Achim Schweikard, Per R Poulsen
PURPOSE: With the trend in radiotherapy moving toward dose escalation and hypofractionation, the need for highly accurate targeting increases. While MLC tracking is already being successfully used for motion compensation of moving targets in the prostate, current real-time target localization methods rely on repeated x-ray imaging and implanted fiducial markers or electromagnetic transponders rather than direct target visualization. In contrast, ultrasound imaging can yield volumetric data in real-time (3D + time = 4D) without ionizing radiation...
October 2016: Medical Physics
https://www.readbyqxmd.com/read/27752252/vestibular-perceptual-thresholds-increase-above-the-age-of-40
#19
María Carolina Bermúdez Rey, Torin K Clark, Wei Wang, Tania Leeder, Yong Bian, Daniel M Merfeld
We measured vestibular perceptual thresholds in 105 healthy humans (54F/51M) ranging from 18 to 80 years of age. Direction-recognition thresholds were measured using standard methods. The motion consisted of single cycles of sinusoidal acceleration at 0.2 Hz for roll tilt and 1.0 Hz for yaw rotation about an earth-vertical axis, inter-aural earth-horizontal translation (y-translation), inferior-superior earth-vertical translation (z-translation), and roll tilt. A large subset of this population (99 of 105) also performed a modified Romberg test of standing balance...
2016: Frontiers in Neurology
https://www.readbyqxmd.com/read/27686250/dual-processing-of-visual-rotation-for-bipedal-stance-control
#20
Brian L Day, Timothy Muller, Joanna Offord, Irene Di Giulio
KEY POINTS: When standing, the gain of the body-movement response to a sinusoidally moving visual scene has been shown to get smaller with faster stimuli, possibly through changes in the apportioning of visual flow to self-motion or environment motion. We investigated whether visual-flow speed similarly influences the postural response to a discrete, unidirectional rotation of the visual scene in the frontal plane. Contrary to expectation, the evoked postural response consisted of two sequential components with opposite relationships to visual motion speed...
October 1, 2016: Journal of Physiology
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