ABSTRACT: BACKGROUND: In their current laboratory-based form, existing vibrotactile sensory substitution technologies that provide cues of body motion are impractical for home-based rehabilitation use due to their size, weight, complexity, calibration procedures, cost, and fragility. Methods: We have designed and developed a cell phone based vibrotactile feedback system for potential ...

Stegemöller EL, Buckley TA, Pitsikoulis C, Barthelemy E, Roemmich R, Hass CJ. Postural instability and gait impairment during obstacle crossing in Parkinson's disease. OBJECTIVE: To examine whether Parkinson's disease (PD) affects gait behavior and stability while walking over an obstacle. DESIGN: Parallel group comparisons were completed in which participants completed ...

Few studies have compared the discomfort caused by vibration in different directions, and few have investigated the vibration discomfort of standing people. This study was designed to compare the discomfort experienced by standing people exposed to sinusoidal vibration in the fore-and-aft, lateral, and vertical directions. Using the method of magnitude ...

BACKGROUND: Stroke-related sensorimotor impairment potentially contributes to impaired balance. Balance measures that reveal underlying limb-specific control problems, such as a measure of the synchronization of both lower limbs to maintain standing balance, may be uniquely informative about poststroke balance control. OBJECTIVE: This study aimed to determine the relationships between clinical ...

One of the most important factors influencing aircraft seating comfort in economy class, is legroom. In an airline interior mock up, with the ability to adjust the seat pitch in a range of 28 inches to 43 inches, a study to investigate the influence of seat pitch on passengers' well-being ...

Achromatic second-order (contrast) Mach bands can be perceived near the contrast ramp between two contrast levels. In this study we show that a repertoire of chromatic second-order Mach bands is also clearly perceived, under equal-luminance conditions (minimum motion technique). The results show that chromatic and achromatic second-order stimuli yield significant ...

: Current steering between adjacent electrodes makes it possible to create more spectral channels than the number of electrodes in an electrode array. With current steering on nonadjacent electrodes, called "spanning," it could be possible to bridge a defective electrode contact or potentially reduce the number of electrode contacts for ...

Since the introduction of neural response telemetry (NRT) for the Nucleus 24 cochlear implant (CI24), researchers and clinicians have investigated the feasibility of using the electrically evoked compound action potential (ECAP) threshold to objectively predict psychophysical measurements that are used in the programming of the speech processor. The ability to ...

When an undulating surface bearing a painted texture is illuminated the resulting shading pattern produces in-phase modulations of the mean luminance (LM) and luminance amplitude (AM) of the texture. Experimentally, in-phase combinations of LM and AM (LM+AM) are seen as undulating surfaces whereas anti-phase combinations (LM-AM) are more ambiguous; being ...

Metacontrast is a powerful visual illusion by which the visibility of a brief stimulus is drastically reduced when it is followed by a snugly fitting second, masking stimulus. There have been longstanding debates about the levels at which metacontrast mechanisms operate and about the temporal unfolding of the masking effect. ...

Since 2002, six blind patients have undergone implantation of an epiretinal 4 × 4 electrode array designed to directly stimulate the remaining cells of the retina after severe photoreceptor degeneration due to retinitis pigmentosa. This study was conducted to investigate how the brightness of percepts is affected by pulse timing ...

A light-sensitive, externally powered microchip was surgically implanted subretinally near the macular region of volunteers blind from hereditary retinal dystrophy. The implant contains an array of 1500 active microphotodiodes ('chip'), each with its own amplifier and local stimulation electrode. At the implant's tip, another array of 16 wire-connected electrodes allows ...

What's known on the subject? and What does the study add? Ureteric obstruction resulted in a differential change in the electrical activity in the proximal and distal ureter with the proximal ureter having an immediate increase in the frequency of electrical impulses whereas in the distal ureter, the antegrade impulse ...

We have investigated the cutaneous perception differences for anodal and cathodal transcranial direct current stimulation (tDCS) and transcranial random noise stimulation (tRNS) between two electrode configurations: a standard, rectangle-shaped, and a circle-shaped, round geometry with the same surface area, and thus, same nominal current distribution. We have aimed to find ...

We find a transformation in the probability density of intensity for light transmitted through stacks of glass slides of increasing thickness from one-dimensional (1D) to quasi-1D statistics. We argue that this represent a crossover to universal first order intensity statistics beyond 1D associated with the appearance of phase singularities at ...

In this cross-sectional study, we investigated the frequency tuning properties of sound-evoked vestibular myogenic potentials in extraocular muscles (OVEMPs) in normal human subjects. Acoustic tone bursts (130 dB pSPL, 10 ms plateau, 1 ms rise/fall) with nine frequencies from 125 to 4000 Hz were presented monoaurally to 12 normal subjects ...

Spread of excitation within the cochlea in response to electrical stimulation can be measured with the electrically evoked compound action potential (ECAP). Different spread of excitation measurement techniques have been reported in the literature. One method uses a fixed stimulus location while varying the recording electrode along the length of ...

When cochlear implant (CI) users are allowed to self-select the "most intelligible" frequency-to-electrode table, some of them choose one that differs from the default frequency table that is normally used in clinical practice. CIs reproduce the tonotopicity of normal cochleas using frequency-to-electrode tables that assign stimulation of more basal electrodes ...

Aims: To evaluate the threshold currents required by different-size electrodes under various stimulus parameters by suprachoroidal-transretinal stimulation (STS) in rabbit eyes. Methods: An electrode array with 4 differently sized electrode contacts (50, 150, 350 and 500 μm in diameter) was implanted into the suprachoroidal space of the rabbit eyes. The ...

This study investigated cochlear implant (CI) users' ability to perceive pitch cues from time-varying virtual channels (VCs) to identify pitch contours. Seven CI users were tested on apical, medial, and basal electrode pairs with stimulus durations from 100 to 1000 ms. In one stimulus set, 9 pitch contours were created ...

In this study, we fabricated an electrostatic actuator probe having curved electrodes and evaluated its applicability for use in time-of-flight scanning force microscopy. In this probe, the end position of a cantilever with a tip is switched through electrostatic pull-in effect; the measurement modes can be changed between mass analysis ...

Low-frequency noise of individual MWNTs was investigated with different metal electrodes. Irrespective of the ohmic or non-ohmic voltage-current characteristics, a strong dependence of the noise on the metal contacts was observed. The good electrical contacts with Pd or Pt electrodes enable a quasi-ballistic transport with a bigger exponent in the ...

Recent technological advances have led to new light-weight battery-operated systems for electrophysiology. Such systems are head mounted, run for days without experimenter intervention, and can record and stimulate from single or multiple electrodes implanted in a freely behaving primate. Here we discuss existing systems, studies that use them, and how ...

Previous studies in waking animals have shown that the frequency structure of olfactory bulb (OB) local field potential oscillations is very similar across the OB, but large low-impedance surface electrodes may have favored highly coherent events, averaging out local inhomogeneities. We tested the hypothesis that OB oscillations represent spatially homogeneous ...

High stimulation rates in cochlear implants (CI) offer better temporal sampling, can induce stochastic-like firing of auditory neurons and can increase the electric dynamic range, all of which could improve CI speech performance. While commercial CI have employed increasingly high stimulation rates, no clear or consistent advantage has been shown ...

The photopic negative response (PhNR) has attracted interest as a flash ERG component reflecting inner retinal activity, with investigators adopting various approaches to analysing the response. This study has two principal aims: first to determine the most reliable technique for assessing the PhNR amplitude; secondly to compare the repeatability characteristics ...

Electrocardiographic (ECG) errors due to electrode cable reversal confuse physicians and provoke unnecessary diagnostic tests. They occur in approximately 4% of ECGs performed in the intensive care unit (ICU). We aimed to investigate whether this frequency could be reduced by an appropriate intervention. All ECGs from consecutive patients were collected ...

Recordings of large neuronal ensembles and neural stimulation of high spatial and temporal precision are important requisites for studying the real-time dynamics of neural networks. Multiple-shank silicon probes enable large-scale monitoring of individual neurons. Optical stimulation of genetically targeted neurons expressing light-sensitive channels or other fast (milliseconds) actuators offers the ...

We study the operation of polymer light-emitting electrochemical cells (LECs) by combining scanning Kelvin probe microscopy with in situ imaging of the electroluminescence and photoluminescence on planar LECs. By combining these techniques on the same device in the same apparatus we directly map the relationship between the spatial distribution of ...

OBJECTIVE: High frequency oscillations (HFO) of 100-500Hz have been reported in epileptic human brain. However, the questions of how fast these oscillations can reach, and which frequency range is clinically important remain unanswered. We recorded interictal and ictal very high frequency oscillations (VHFO) of 1000-2500Hz by subdural electrodes using 10kHz ...

Electrowetting-on-dielectric (EWOD) promises to be an important lab-on-a-chip approach for effectively manipulating droplets with electric field-controlled surface tension. Droplets manipulated in electrowetting-based devices are typically sandwiched between two parallel plates and actuated by digital electrodes. The size of pixilated electrodes limits the minimum droplet size that can be manipulated. Here, ...

We present a novel quartz cantilever for frequency-modulation atomic force microscopy (FM-AFM) which has three electrodes: an actuating electrode, a sensing electrode, and a ground electrode. By applying an ac signal on the actuating electrode, the cantilever is set to vibrate. If the frequency of actuation voltage closely matches one ...

Dye-sensitized photovoltaic wires (DSPVWs) are developed using anodized Ti wires that contain ordered arrays of TiO2 nanotubes. The prototype DSPVW consists of N719 dye-adsorbed TiO2 nanotube arrays around a Ti wire as a working electrode, a platinum wire as a counter electrode, and an organic electrolyte encased in a capillary ...

A micro-structure supported on a droplet is subjected to capillary force and aligned dependent on its shape. If the droplet's boundary conditions at the bottom and the micro-structure are non-circular, capillary torque is exerted on the structures. The direction of torque is determined by the boundary conditions and the position ...

This work demonstrates a large-scale batch fabrication of GaN light-emitting diodes (LEDs) with patterned multi-layer graphene (MLG) as transparent conducting electrodes. MLG films were synthesized using a chemical vapor deposition (CVD) technique on nickel films and showed typical CVD-synthesized MLG film properties, possessing a sheet resistance of [Formula: see text] ...

OBJECTIVE: Current mainstream EEG electrode setups permit efficient recordings, but are often bulky and uncomfortable for subjects. Here we introduce a novel type of EEG electrode, which is designed for an optimal wearing comfort. The electrode is referred to as C-electrode where "C" stands for comfort. METHODS: The C-electrode does ...

This article presents results of detailed and direct real-time observations of the wide variety of SnO(2) nanobelt motions induced by ac dielectrophoresis (DEP) in an innovative microfluidic setup. High ac electric fields were generated on a gold microelectrode (approximately 20 microm electrode gap) array, patterned on a glass substrate and ...

Three experiments studied discrimination of changes in the rate of electrical pulse trains by cochlear-implant (CI) users and investigated the effect of manipulations that would be expected to substantially affect the pattern of auditory nerve (AN) activity. Experiment 1 used single-electrode stimulation and tested discrimination at baseline rates between 100 ...

Estimates of place-pitch sensitivity in cochlear implant (CI) users are typically obtained using electric pulse trains presented directly to the implanted electrodes. Such estimates may overestimate the place-pitch sensitivity available to these listeners through their speech processors due to spectral smearing by the analysis filters. To determine the influence of ...

This paper describes a design and implementation of a portable physiological signal recorder. The device is designed for measuring electrocardiography, bioimpedance, and user's activity. The bioimpedance measures the dynamic changes in the impedance, and its main application is monitoring user's respiration. Activity is measured with three-axis acceleration sensor. During the ...

OBJECT: Intraoperative monitoring of visual evoked potentials (VEPs) has been regarded as having limited significance for the preservation of visual function during neurosurgical procedures, mainly due to its poor spatial resolution and signal-to-noise ratio. The authors evaluated the usefulness of cortically recorded VEPs, instead of the usual scalp VEPs, as ...

We can detect visual movements not only from luminance motion signals (first-order motion) but also from non-luminance motion signals (second-order motion). It has been established for first-order motions that the visual system pools local one-dimensional motion signals across space and orientation to solve the aperture problem and to estimate two-dimensional ...

Biopotential measurements with capacitive electrodes do not need any direct contact between electrode and skin, which saves the time devoted to expose and prepare the contact area when measuring with conductive electrodes. However, mechanical vibrations resulting from physiological functions such as respiration and cardiac contraction can change the capacitance of ...

Gold electrodes with switchable conductance are created by coating the gold surface with different colloidal quantum dots. For the quantum dot immobilization, a dithiol compound was used. By polarizing the electrode and applying a light pointer, local photocurrents were generated. The performance of this setup was characterized for a variety ...

The aim of the present study was to examine cochlear implant (CI) users' perceptual segregation of speech from background noise with differing degrees of electrode separation between speech and noise. Eleven users of the nucleus CI system were tested on consonant identification using an experimental processing scheme called "multi-stream processing" ...

The delivery of stimulus by a deep brain stimulation (DBS) contact electrode at a particular location may lead to a quantifiable physiologic effect, both intraoperatively and postoperatively. Consequently, measured data values can be attributed to discrete scattered points in neuroanatomic space, allowing for interpolative techniques to generate a topographic map ...

This article shows that differences in the waveforms of the electric organ discharges (EODs) from two taxa are due to the different responsiveness of their electric organs (EOs) to their previous activity (auto-excitability). We compared Gymnotus omarorum endemic to Uruguay (35 degrees South, near a big estuary), which has four ...

The purpose of this study was to develop techniques to quantify the propagation pattern of the electrical activation during atrial fibrillation (AF) along a one-dimensional catheter. Taking intra-atrial signal organization aspects into account, the atrial activations are detected and combined into wavefronts. Parameters describing wavefront consistency and activation order along ...

Visual evoked potentials (VEPs) can provide important diagnostic information regarding the functional integrity of the visual system. This document updates the ISCEV standard for clinical VEP testing and supersedes the 2004 standard. The major change in this revision is that test parameters have been made more precise to achieve better ...

Implanted intraocular microelectrode arrays are being used to provide sight to individuals who are blind due to photoreceptor degeneration. It is envisioned that this retinal prosthesis will create the illusion of motion by stimulating focal areas of the retina in a sequential fashion through neighboring electrodes, much like the rapid ...