Plane Thickness Research Articles

On-wafer magnetically tunable millimeter wave notch filter using M-phase Ba hexagonal ferrite/Pt thin films on Si

A prototype of a fully integrated on-wafer, magnetically tunable band-stop filter operating at millimeter wave frequencies is demonstrated on a Si substrate. In contrast to earlier studies, the filter uses a very thin barium hexagonal ferrite film incorporated into the dielectric layer of a microstrip transmission line to filter the signal. The zero-field operational frequency is about 34 GHz, increasing linearly with the strength of a static, perpendicularly applied magnetic field at a rate of about 2.7 GHz/kOe. Experimentally, high signal attenuation (33–67 dB/cm) at the resonance frequency and insertion losses as low as 4.5 dB were simultaneously observed, while the 3 dB device bandwidths were generally below 1 GHz. Our calculations are in quantitative agreement with the experimental results. We also find an important result that the thickness and conductivity of the Pt ground plane plays a key role in insertion losses, indicating directions for further improvements.

Controlling the sedimentological realism of deltaic reservoir models by the use of intelligent sedimentological prior information

T he generation of multiple reservoir models that match production data is one of the advantages of automatic history matching. Including facies geometry varia­tions within the AHM process without the modeller control could result in the selection of reservoir models that match production data but lack of sedimentological realism (facies geometry that mimic the geometry observed in nature). These unrealistic models will cause problems in production forecasting and reserves estimation. In this article, a technique is proposed to guarantee sedimentological realism within the AHM process. Building realistic prior models that describe the non-linear dependencies between sedimentological parameters of deltaic systems can prevent the development of geologically unrealistic reservoir models. Multi-dimensional realistic priors were generated using One-Class Support Vector Machine. This technique captures hidden relations of deltaic param­eters: Delta Plane Width, Length and Thickness; Distributary Channel Width and Thickness, Meander Amplitude, and Wavelength and Mouth bar dimensions. Variables are sampled from the realistic priors in order to assure facies realism. A Multiple Point Statistics (MPS) algo­rithm is used to model facies in a deltaic reservoir. Variability of facies geometry is produced by changing the MPS geometri­cal parameter, different training images and regions. History-matched models produced under geological realis­tic constraints reduce uncertainty of the production prediction, ensures the realism of the selected reservoir and also helps in the identification of the reservoir geometry.

An approach to estimate the position of the shear plane for colloidal particles in an electrophoresis experiment

The existence of the shear layer has great influence on the stability of colloidal systems and it is an important physicochemical parameter in the field of colloid and interface chemistry. However, to date, people do not know the actual position of the shear plane, and there is no theory to calculate the shear layer thickness. Conventionally, it is thought that the shear plane is very close to the Stern plane. In this study, a new theory for calculating the thickness of the shear layer for a planar charged colloidal particle in an aqueous solution was established; the shear layer thickness can be obtained based on the surface potential (the potential at the original plane of diffusion layer) and zeta potential of colloidal particles. The results showed that the surface potential of montmorillonite in various electrolyte solutions was approximately 3 to 6 times larger than the corresponding zeta potential. The thickness of the shear plane was dependent on the surface potential in the aqueous solution, and the shear plane was located far from the Stern plane but close to the Gouy plane, contradicting the widely accepted, erroneous placing of the shear plane close to the Stern plane. This study also showed that, ionic polarization in the electric field of the diffuse layer will significantly decrease the surface potential and the position of the shear plane.

Stability and amorphization of Cu–Nb interfaces during severe plastic deformation: Molecular dynamics simulations of simple shear

Molecular dynamics is used to investigate in-plane simple shear deformation of three Cu–Nb interfaces with either Kurdjumov–Sachs (KS) or Nishiyama–Wassermann (NW) orientation relationships (ORs). Regardless of the shear direction, both the NW interface and the KS interface with a {111}fcc||{110}bcc habit plane consistently deform via pure interface sliding and are highly stable against the shear deformation. In contrast, the KS interface with a {112}fcc||{112}bcc habit plane exhibits at small strain various deformation mechanisms along different shear directions. Dislocation glide inside the Cu phase results in a change from the original OR. At large strains, additional strain is accommodated almost entirely by localized shearing at interfacial amorphous layers, which grow as the square root of strain, irrespective of shear direction, phase layer thickness or habit plane. With the onset of such shear localization, a new OR becomes stabilized, although it varies with shear direction. The findings in this study are discussed with respect to structural evolution, amorphization, forced mixing, shear strength and experimental observations.

Prevention and management of postoperative air leaks.

A contemporary, practical definition of prolonged air leak (PAL) is an air leak that lasts beyond postoperative day 5. This is consistent with the definition used in the Society of Thoracic Surgeons database and represents a leak whose duration exceeds the average length of stay (LOS) for lobectomy. The reported incidence of PAL ranges from 8% to 26% (1), but the definition of PAL has varied amongst reports. PAL increases the LOS, increases hospital costs, and is associated with elevated rates of empyema and other complications. The most consistently reported risk factors for PAL include poor pulmonary function, use of steroids, performance of an upper lobectomy, presence of a pneumothorax coinciding with an air leak, and the presence of pleural adhesions (1,2). With regard to sublobar resection, although it has yet to be studied scientifically, we believe that segmentectomy may have a higher risk of PAL compared to wedge resection due to the increased thickness of some intersegmental planes and the more extensive dissection involved.

Failure mode maps for circular composites sandwich plates under bending

Abstract Competing failure modes are investigated for circular sandwich plates comprising quasi-isotropic E-glass/epoxy composite faceplates (with [−60/0/60] ns configuration) and polyvinyl chloride (PVC) foam core under bending. Clamped sandwich plates are loaded using flat-ended punch at the center of the plate. Three competing failure modes, viz., core indentation, core shear and face failure/microbuckling, are considered. Analytical estimates for elastic response (stiffness) and initial failure load are proposed, and these are verified by experimental measurements and finite element (FE) predictions. Good agreement (with in ±20%) is observed among analytical estimates, experimental measurements and FE predictions. Analytical estimates for the failure modes are used to plot the failure mode map in non-dimensional plate radius versus faceplate thickness plane for a given material system. The failure mode map thus constructed is assessed by considering a few sandwich plate geometries. Normalized sandwich mass and failure load contours are superimposed onto the failure mode map to identify the locus of minimum weight design by numerical search. Effect of geometrical parameters of the sandwich plate on failure load and mode is also investigated.

Inclusion of surface anisotropy in the micromagnetic analysis of exchange-coupled hard/soft bilayers

The effects of surface anisotropy and interface anisotropy in soft and hard layers have been considered in the frame of a previously developed micromagnetic continuum model for the study of demagnetization processes in exchange-coupled bi- and multi-layers of soft/hard-type with planar and perpendicular anisotropy, in order to extend and generalize it. In particular, fields applied along the easy direction and strong interface ferromagnetic coupling have been considered. The theoretical results have been applied to a bilayer with perpendicular anisotropy in the hard layer and positive perpendicular surface anisotropy in the soft layer, in order to compare them with those obtained by considering the equivalent volume anisotropy in the soft layer. Moreover, the separate effects of positive perpendicular surface and interface anisotropies in the bilayer have been compared. We have deduced the nucleation field equation and obtained plots of the nucleation field as a function of the soft layer thickness and of the surface and interface anisotropies. Demagnetization curves have been also calculated. The nucleation process can be reversible (exchange-spring (ES) regime) or irreversible (rigid magnet (RM) regime) depending on magnetic and geometrical parameters. The critical equation, which allows determining the boundary between RM and ES regions, has been deduced. Corresponding phase diagrams in the plane of soft and hard layer thickness have been obtained as a function of surface and interface anisotropies.

The Variable Capacitance Model: A Strategy for Treating Contrasting Charge-Neutralizing Capabilities of Counterions at the Mineral/Water Interface

Thermodynamic models predicting ion adsorption at mineral/water interfaces can have limitations from the simplifying assumptions that compact plane thicknesses and capacitance values are constant, and that charge densities of electrolyte counterions of different charge-to-size ratios lie at the same planes of adsorption, or split between different planes. To address these limitations a thermodynamic adsorption modeling framework was developed to account for coexisting compact planes for each type of counterion complexes formed on a single mineral surface. This framework was developed to predict charge development at lepidocrocite (γ-FeOOH) particle surfaces suspended in aqueous solutions of NaCl and NaClO4. The model incorporates properties of Cl(-), ClO4(-), and Na(+) complexes formed at the (001) and (010) faces of this mineral obtained by molecular dynamics (MD) simulations. This concept was incorporated in a thermodynamic adsorption model that predicts an overall variable compact plane capacitance in terms of a linear combination of the capacitances of ion-specific EDL structures scaled for their relative surface loadings. These capacitance values are in turn constrained by compact plane thicknesses of every Cl(-), ClO4(-), and Na(+) complex, based on their MD-derived structures and atomic densities. The model predicts experimental potential-determining (H+, OH-) data for submicrometer-sized synthetic lepidocrocite particles exhibiting both (001) and (010) faces. It also isolates electrostatic contributions from these faces. A computer code solving for this Variable Capacitance Model--VCM--is provided in the Supporting Information section of this article, and can be readily modified to predict molecular-level details of any other mineral/water interface systems using this methodology.

How to improve MRI accuracy in detecting deep infiltrating colorectal endometriosis: MRI findings vs. laparoscopy and histopathology

To verify whether the capability of magnetic resonance imaging (MRI) in diagnosing deep infiltrating colorectal endometriosis (DICE) is improved using an association of MRI findings. The imaging database of our Institute of Radiology was retrospectively reviewed to identify patients subjected to MRI for a suspicion of deep infiltrating endometriosis. Medical history was then investigated and only patients who were also subjected to laparoscopy (LA) were included. Absence of LA represented the exclusion criterion. Images were evaluated twice by two radiologists using two different diagnostic criteria for an abnormal result: the contemporary presence of nodules or hypointense plaque-like lesions in the adjacent fat plane and bowel wall thickness, without (first criterion) or with (second criterion) semicircular shape (i.e. "radial and retracting shape"). Radiologists worked in consensus evaluating images in two separate sessions, using the first criterion in the first section and the second criterion in the second one. MRI results were compared with LA or histopathology as the gold standard by 2×2 tables and statistically analyzed (k statistics). Likelihood-ratio test was also performed, being independent from the prevalence of the disease. By consulting case sheets, 33/50 females (ranging age 24-39years, mean age 32.2years) who were subjected to MRI also underwent LA. Intestinal resection for DICE was performed in 11/33 patients; in 22/33 superficial intestinal foci, adhesions/nodules in the fat plane were simply removed. When the first criterion was applied, MRI agreement with histopathology or LA was poor (51.5%) (k value=0.20; p<0.055), while it was improved (96.9%) when using the second diagnostic criterion (k value=0.93; p<0.0000). Likelihood ratio was 1.375 (95% CI 0.69-2.72) using the first and 22 (95% CI 20.08-24.1) using the second criterion. The second criterion, or the joint presence of nodules or hypointense plaque-like lesions in the adjacent fat plane and bowel wall thickness showing "radial and retracting shape", improves MRI capability in DICE diagnosis. It can be considered an effective indicator of DICE on T2-weighted images at 1.5-T MRI, and can ensure the correct preoperative assessment of the disease for the best therapeutic procedure and treatment planning.

Relative peak frequency increment method for quantitative thin-layer thickness estimation

Quantitative thickness estimation of thin-layer is a great challenge in seismic exploration, especially for thin-layer below tuning thickness. In this article, we analyzed the seismic response characteristics of rhythm and gradual type of thin-layer wedge models and presented a new method for thin-layer thickness estimation which uses relative peak frequency increment. This method can describe the peak frequency to thickness relationship of rhythm and gradual thin-layers in unified equation while the traditional methods using amplitude information cannot. What’s more, it won’t be influenced by the absolute value of thin-layer reflection coefficient and peak frequency of wavelet. The unified equations were presented which can be used for rhythm and gradual thin-layer thickness calculation. Model tests showed that the method we introduced has a high precision and it doesn’t need to determine the value of top or bottom reflection coefficient, so it has a more wide application in practice. The application of real data demonstrated that the relative peak frequency increment attribute can character the plane distribution feature and thickness characteristic of channel sand bodies very well.

Metamaterial Inspired Optically Transparent Band-Selective Ground Planes for Antenna Applications

This paper presents a technique for design of wideband optically transparent band-selective ground planes (BSGP) using the concept of miniaturized element frequency selective surfaces (MEFSS). The proposed multi-layer approach can provide very large bandwidth and high out of band rejection while keeping the thickness of the ground plane very low. Essentially the thickness of the ground plane made to be almost independent of the bandwidth in order to reduce its weight and sensitivity to the angle of incidence and the shape of the wavefront of the incoming radiation. As a starting point, a single pole MEFSS is studied and its performance in terms of transparency and bandwidth is compared to the traditional wire grid and transparent conductive coatings. Next, the proposed multi-pole BSGP design method is introduced and its performance is evaluated numerically and experimentally.

The influence of nano-particle tracers on the slip length measurements by microPTV

Direct measurement of slip length is based on the measured fluid velocity near solid boundary. However, previous micro particle image velocimetry/particle tracking velocimetry (microPIV/PTV) measurements have reported surprisingly large measured near-wall velocities of pressuredriven flow in apparent contradiction with the no-slip hypothesis and experimental results from other techniques. To better interpret the measured results of the microPIV/PTV, we performed velocity profile measurements near a hydrophilic wall (z = 0.25–1.5 μm) with two sizes of tracer particles (ϕ 50 nm and ϕ200 nm). The experimental results indicate that, at less than 1 μm from the wall, the deviations between the measured velocities and no-slip theoretical values obviously decrease from 93% of ϕ200 nm particles to 48% of ϕ50 nm particles. The Boltzmann-like exponential measured particle concentrations near wall were found. Based on the non linear Boltzmann distribution of particle concentration and the effective focus plane thickness, we illustrated the reason of the apparent velocity increase near wall and proposed a method to correct the measured velocity profile. By this method, the deviations between the corrected measured velocities and the no-slip theoretical velocity decrease from 45.8% to 10%, and the measured slip length on hydrophilic glass is revised from 75 nm to 16 nm. These results indicated that the particle size and the biased particle concentration distribution can significantly affect near wall velocity measurement via microPIV/PTV, and result in larger measured velocity and slip length close to wall.

Pulmonary Intersegmental Planes: Imaging Appearance and Possible Reasons Leading to Their Visualization

To describe the normal imaging appearance of pulmonary intersegmental planes on thoracic computed tomographic (CT) scans and determine the possible reasons related to their visualization in terms of aging and anatomy. The study was approved by the internal ethics review board. Informed consent was obtained. A retrospective review was undertaken of 104 thoracic multidetector CT scans of an older group (>65 years) and younger group (<55 years). The number, location, and appearance rate of intersegmental planes were assessed. Group comparisons were made, and linear regression analysis was used to assess relationships between age and visualization of intersegmental planes. Thirty lung samples (10 × 10 × 10 mm(3)) from autopsy were scanned by using micro-CT. Thicknesses of intersegmental planes were measured. Significant differences of the thickness between visible and invisible intersegmental planes were assessed with the independent t test. In five fetal specimens (17-21 weeks in gestational age), 7.0-T magnetic resonance (MR) imaging was performed to determine the congenital difference of thickness of intersegmental planes. Within the right lung, appearance rates of visible intersegmental planes were 71.2% at S1-S3, 54.8% at S4-S5, and 70.2% at S7-S10. Within the left lung, appearance rates of visible intersegmental planes were 39.4% at S1+2 to S3, 64.4% at S4-S5, 18.3% at S7-S8, and 89.4% at S7-S10. Appearance rates of visible intersegmental planes on thoracic CT scans were not significantly different (P ≥ .38) between younger and older groups. Mean thicknesses of visible and invisible intersegmental planes were 681.3 μm ± 75.3 (standard deviation) and 221.7 μm ± 54.1, respectively. Visible intersegmental planes were significantly thicker than invisible intersegmental planes (P < .05). Visible intersegmental planes were also seen on fetal lung 7.0-T MR images. The thickness of pulmonary intersegmental planes and variation of intersegmental veins were closely related to visualization of intersegmental planes on thoracic CT scans. Aging was excluded as the possible reason.

Thermal Evaluation of High-Current Polyimide Rigid and Rigid-Flex Printed Wiring Board Trace Widths in a Vacuum

This paper details the thermal evaluation of high-current polyimide rigid and rigid-flex printed wiring boards in a vacuum. Although industry standards, such as IPC-2152 or MIL-STD-275, can be used to determine required trace width for PWB traces that carry current to between 20 or 30 amps for multiple copper plane thicknesses, they typically cannot be used to determine trace width for PWB traces that handle current greater than 15 amps. This paper presents results from testing and analysis of high-current rigid and rigid-flex PWBS that must carry current of up to 60 amps. Testing was performed in vacuum on a controlled-temperature platen, measuring board temperature at specific locations to determine performance of different trace widths using 2 and 4 ounce copper layers. A thermal imaging camera was used to identify PWB hot spots. Test results were compared to IPC-2152 standards, extrapolated to 60 amps current.

Cleavage and size reduction of graphite crystal using ultrasound radiation

The influence of ultrasound radiation on graphite structure was studied by laser light scattering, X-ray diffraction, Raman spectroscopy and Transmission Electron Microscopy. Irradiations of polycrystalline graphite powder suspensions at frequencies of 20kHz and 500kHz, were carried out in three different solvents: water (as the best medium for cavitation), a surfactant (OMImBr) aqueous solution and also a mixture of sulfuric and nitric acids which caused the exfoliation by intercalation. The average basal particle size of 168μm was reduced to 4μm after ultrasonication delivering a huge energy density up to 1.2MW/m2. Change of the sonication time and the nature of the solvents produced different reduction of the graphite crystals dimensions, affecting the out of plane thickness and the basal width as well. The ultrasonication promoted the disordering of the graphite tridimensional stacking for all solvents used, with the strongest effect in acidic medium. Turbostratic structures formation and exfoliation of graphene flakes have been observed after the use of surfactant for sonication medium. Intercalation in acid medium prior to the ultrasound treatment produced similar effects.

Cortical thickness of supratemporal plane predicts auditory N1 amplitude

The auditory-evoked potential's N1 component of the scalp electroencephalogram is a well-established measure of electrical brain activity. The N1 reflects basic auditory processing and is modulated by auditory experience, for instance, by musical training. Here, we explore a possible correlation between the auditory N1 amplitude and cortical architecture in the supratemporal plane. We hypothesize that individual differences in N1 amplitude reflect differential acuity, which might also be reflected by differences in auditory cortex anatomy. Auditory potentials evoked by sine wave tones and structural MRI were collected from 27 healthy volunteers. The thickness and surface area of the cortex were calculated using a surface-based morphometry approach. Cortical thickness, rather than surface area, in a cluster on the posterior supratemporal plane, predominantly located on Heschl's sulcus and lateral aspects of Heschl's gyrus, correlated with the N1 amplitude. In particular, lower cortical thickness was associated with larger N1 amplitudes. This is well in agreement with previous functional magnetic resonance studies reporting a thinner cortex to be related to a larger functional response.

Optokinetic stimulation can break Listing's law without induction of eye movement

Pseudo-images of three-dimensional eye movements captured on an infrared video oculogram can be translated onto a rotational expression around axial vector. This provides a subject's Listing's plane, which moves according to the head's orientation relative to gravity. Optokinetically induced changes in the cognitive gravitational reference frame will affect the context of Listing's plane. The purpose of this study was to estimate the effect of OKS on Listing's plane. In this study, we presented vertical optokinetic visual stimulation with fixation targets, which are thought to induce pseudo-inclination of the head, and evaluated changes in the subjects' Listing's plane. We observed no stimulus-induced movement of Listing's plane that corresponded to the assumed pseudo-recognition of a change in verticality. On the other hand, we did observe vergence movement of Listing's plane (in the yaw plane), which corresponded to exposure to diminished and increased gravitational circumstance. In addition, the thickness of Listing's plane significantly increased with the load of each stimulation. Vertical OKS leads to a rotation of Listing's plane mainly around a vertical axis. This may represent false exhibition of central compensatory re-weighting with respect to inherent otoconial mass asymmetry resulting from the OKS-mediated loss of the gravity reference. In addition, a OKS-mediated thickening of Listing's plane suggests to us that confusing visual input can reduce the stability of the internal model, which would likely manifest itself as a thickening of Listing's plane. In other words, fluctuation between the build-up and drop-out of vection induced by optokinetic stimulation will cause a thickening of Listing's plane. The thickness of Listing's plane could be a novel clinical parameter for quantitatively evaluating static vestibular function and accuracy of the internal model.

Effect of slice thickness on detectability in breast CT using a prewhitened matched filter and simulated mass lesions

Dedicated breast CT (bCT) is an emerging technology with the potential to improve the detection of breast cancer in screening and diagnostic capacities. Typically, the 3D volume reconstructed from the scanner is displayed as sectional images. The purpose of this study was to evaluate the effect of section thickness on the detectability of simulated masses using a prewhitened matched filter (PWMF) as a model observer. A breast CT scanner has been designed and fabricated in the authors' laboratory with more than 200 women imaged in IRB-approved phase I and phase II trials to date. Of these, 151 bilateral data sets were selected on the basis of low artifact content, sufficient breast coverage, and excluding cases with breast implants. BIRADS breast density ratings were available for 144 of these patients. Spherical mass lesions of diameter 1, 2, 3, 5, 11, and 15 mm were mathematically generated and embedded at random locations within the parenchymal region of each bCT volume. Microcalcifications were not simulated in this study. For each viewing plane (sagittal, axial, and coronal) and section thickness (ranging from 0.3 to 44 mm), section images of the breast parenchyma containing the lesion were generated from the reconstructed bCT data sets by averaging voxels over the length of the section. Using signal known exactly (SKE) model observer methodology, receiver operating characteristic (ROC) curve analysis was performed on each generated projected image using a PWMF based model observer. ROC curves were generated for each breast data set, and the area under the ROC curve (AUC) was evaluated as well as the sensitivity at 95% specificity. For all lesion sizes, performance rises modestly to a peak before falling off substantially as section thickness increases over the range of the study. We find that the optimal section thickness tracks the size of the lesion to be detected linearly with a small positive offset and slopes ranging from 0.27 to 0.44. No significant differences were observed between left and right breasts. Performance measures are negatively correlated with measures of breast density, with an average correlation coefficient of -0.48 for the BIRADS breast density score and -0.81 for the proportion of glandular tissue in the breast interior. This study shows quantitatively how PWMF detection performance of a known lesion size is influenced by section thickness in dedicated breast CT. While the optimal section thickness is tuned to the size of the lesion being detected, overall performance is more robust for thin section images compared to thicker images.

Influence of film casting method on block copolymer ordering in thin films

We study the orientation of the cylinder phase of the block copolymer (BCP) poly(styrene-block-methylmethacrylate) (PS-b-PMMA) in thin spun-cast films having a range of film thicknesses and temperatures and compare to our earlier observations on flow-coated films of the same BCP under similar thermodynamic conditions. As in our former measurements on flow-coated films, morphology maps of our spun-cast BCP films reveal distinct ordering regimes where the cylinders orient predominantly perpendicular or parallel to the interface and an ‘intermediate’ regime where these morphologies are mixed. However, we find that the locations of these morphology lines in the temperature–film thickness plane are greatly influenced by the method of film formation. We hypothesize that the slow solvent evaporation of the flow-coated films leads to films having higher residual stresses than spun-cast films because of a relatively inhibited transport of the solvent out of the film during drying, and annealing measurements on both types of cast films provide supporting evidence that the BCP surface morphology change is associated with residual stresses within the films. Contrary to our initial expectations, spun-cast films showed little sensitivity to film casting speed so that residual stress effects associated with the comparatively violent fluid flow conditions of spin-casting appear to be small. Instead, residual stresses arising from slow film evaporation appear to be implicated. Residual stress effects arising during the course of film casting and drying are relevant to other fabrications involving cast polymer films, such as in organic photovoltaic devices where flow-coating or similar industrial film casting method is normally employed for film formation.

Changes in Listing Plane Thickness Caused by Vestibular Schwannoma

Three-dimensional analysis of video-oculograms can be used to calculate Listing plane for patients and experimental subjects. Listing plane reflects the head's orientation with respect to gravity, which suggests that the plane is derived from otolithic vestibular input, itself, or from a gravity-oriented internal model constructed through integration of visual, vestibular, and proprioceptive sensory inputs. The goal of this study was to determine whether the Listing plane can serve as a parameter for evaluating static (peripheral or central) vestibular function. Prospective study. Tertiary referral center. Healthy subjects and patients with unilateral vestibular schwannoma without any previous treatment. Diagnostic. Video-oculograms were recorded from healthy subjects (aged 36.8 ± 6.3 yr) and from patients (aged 60.3 ± 7.5 yr) during voluntary gaze with the head in an upright or each-side-down orientation, and the thicknesses of the calculated Listing planes were then compared. Results revealed thickening of the Listing plane in patients only when the head was in an impaired-side-down orientation (1.250 ± 0.795 and 1.074 ± 0.759 degrees in the right- and left-side-down head orientations in healthy subjects versus 2.222 ± 1.237 degrees in the impaired-side-down orientation in patients), and this thickening correlated with caloric weakness. By contrast, neither the sensation of postural instability nor postural disturbance in force platform recordings contributed to the thickness of Listing plane. The thickness of the Listing plane could be a novel parameter for quantitatively evaluating static vestibular (otolithic) function, although central compensation might exist.