Motion Sensitivity Research Articles

Human RAMP1 overexpressing mice are resistant to migraine therapies for motion sensitivity.

Both enhanced motion-induced nausea and increased static imbalance are observed symptoms in migraine and especially vestibular migraine (VM). Motion-induced nausea and static imbalance were investigated in a mouse model, nestin/hRAMP1, expressing elevated levels of human RAMP1 which enhances CGRP signaling in the nervous system, and compared to non-affected littermate controls. Behavioral surrogates such as the motion- induced thermoregulation and postural sway center of pressure (CoP) assays were used to assess motion sensitivity. Nausea readouts revealed that the nestin/hRAMP1 mouse exhibit an increased sensitivity to CGRP's effects at lower doses compared to unaffected controls. In addition, the nestin/hRAMP1 mice exhibit a higher dynamic range in postural sway than their wildtype counterparts, along with increased sway observed in nestin/hRAMP1 male mice that was not present in male unaffected controls. Results from migraine blocker experiments were challenging to interpret, but the data suggests that olcegepant is incapable of reversing CGRP-induced or endogenous alterations in the nestin/hRAMP1 mice, while rizatriptan was ineffective in both the nestin/hRAMP1 and control mice. The results indicate that overexpression of hRAMP1 leads to heightened endogenous CGRP signaling. Results also suggest that both olcegepant and rizatriptan are ineffective in reducing nausea and sway in this hypersensitive CGRP mouse model. This study suggests that the hypersensitive nestin/hRAMP1 mouse may serve as a model for difficult to treat cases of migraine that exhibit increased motion sensitivity.

Characterizing brain mechanics through 7 tesla magnetic resonance elastography

Magnetic resonance elastography (MRE) is a non-invasive method for determining the mechanical response of tissues using applied harmonic deformation and motion-sensitive MRI. MRE studies of the human brain are typically performed at conventional field strengths, with a few attempts at the ultra-high field strength, 7T, reporting increased spatial resolution with partial brain coverage. Achieving high-resolution human brain scans using 7T MRE presents unique challenges of decreased octahedral shear strain-based signal-to-noise ratio (OSS-SNR) and lower shear wave motion sensitivity. In this study, we establish high resolution MRE at 7T with a custom 2D multi-slice single-shot spin-echo echo-planar imaging sequence, using the Gadgetron advanced image reconstruction framework, applying Marchenko-Pastur Principal component analysis denoising, and using nonlinear viscoelastic inversion. These techniques allowed us to calculate the viscoelastic properties of the whole human brain at 1.1 mm isotropic imaging resolution with high OSS-SNR and repeatability. Using phantom models and 7T MRE data of eighteen healthy volunteers, we demonstrate the robustness and accuracy of our method at high-resolution while quantifying the feasible tradeoff between resolution, OSS-SNR, and scan time. Using these post-processing techniques, we significantly increased OSS-SNR at 1.1 mm resolution with whole-brain coverage by approximately 4-fold and generated elastograms with high anatomical detail. Performing high-resolution MRE at 7T on the human brain can provide information on different substructures within brain tissue based on their mechanical properties, which can then be used to diagnose pathologies (e.g. Alzheimer's disease), indicate disease progression, or better investigate neurodegeneration effects or other relevant brain disorders,in vivo.

Motion sickness whilst reading as a passenger in the car is highly predictive of vestibular migraine.

Vestibular Migraine (VM) is a prevalent vestibular disorder, affecting up to 2.7% of the general population. Despite the establishment of diagnostic criteria by the Bárány Society and its inclusion in the International Classification of Headache Disorders, the clinical diagnosis of VM remains challenging due to its complex pathophysiology and symptom overlap with other dizziness disorders. Motion sickness is a core feature of migraine and can be interrogated through simple questionnaires. This study aims to identify to what extent motion sensitivity can predict VM compared to other causes of dizziness. We conducted a cross-sectional study involving 113 patients from the vestibular neurology clinics at University College London Hospitals. Participants were categorized into VM, Persistent Postural Perceptual Dizziness (PPPD), combined VM and PPPD, and 'other' dizziness etiologies. Data on motion sickness history and dizziness during car travel were collected through structured interviews and analyzed using logistic regression to assess the predictive value of these symptoms for VM. A substantial portion of patients with VM (91.2%) reported nausea or dizziness when reading as a passenger, a symptom significantly more prevalent than in those with PPPD or other dizziness diagnoses. Logistic regression indicated that VM patients are significantly more likely to experience these symptoms compared to non-VM patients, with an odds ratio suggesting a strong predictive value for this symptom in diagnosing VM. The findings highlight increased motion sensitivity while reading in a moving vehicle as a promising diagnostic tool for VM, offering a practical aid in clinical settings to distinguish VM from other vestibular disorders.

Effect of Reynolds Number and Aeroelastic Scaling Upon Launch-Vehicle Ground-Wind Loads

NASA conducted a launch vehicle ground-wind-loads investigation at the NASA Langley Transonic Dynamics Tunnel to investigate wind-induced oscillations (WIOs) of a launch vehicle when exposed to ground winds before launch. Previous publications from this effort have documented the effects of an atmospheric-boundary-layer profile on WIO response and the correlation process between model-scale and full-scale wind characteristics and resulting structural loads. This paper will focus on the importance of aeroelastic scaling and the impact of Reynolds number on WIO response. As described in the literature and confirmed in the present investigation, aeroelastic effects can significantly increase the magnitude of measured loads. Additionally, vortex shedding is sensitive to nuances of the flow in the shear layer, which is governed by Reynolds number. Many wind-tunnel facilities are not capable of producing flight Reynolds numbers for the ground-wind-loads problem. At very low Reynolds numbers, laminar shear layers exhibit different behavior, resulting in different vortex frequencies, oscillating lift magnitudes, and motion sensitivities. This investigation demonstrated that low Reynolds number testing can yield substantially lower dynamic loads with less aeroelastic coupling than those acquired at flight-representative Reynolds numbers for a resonant WIO event. Additionally, a resonant response phenomenon present at flight Reynolds number was absent at low Reynolds number. Conversely, for nonresonant WIO response conditions, similar dynamic load coefficients were obtained for similar test velocities at either Reynolds number condition. These findings impact many large launch vehicles, including the NASA Space Launch System series of vehicles.

EAPTON: Event-based Antinoise Powerlines Tracking with ON/OFF Enhancement

Abstract Event-based powerlines detection and tracking is a thriving research topic with significance in autonomous powerlines inspection, especially for payload-limited UAVs. Currently, event-based line detection methods are developed to address line detection in dynamic scenes, including UAV-based powerlines tracking. However, due to the motion sensitivity of event cameras, it is challenging to eliminate false line detection caused by clustered events from a complex background. Taking inspiration from animals’ motion vision, we propose the EAPTON algorithm to address the vulnerable robustness against complex backgrounds. In our method, the brightness increments (ON events) and decrements (OFF events) are separately processed in parallel pathways, which is prevalent in animals’ motion vision. To increase selective sensibility to powerlines, we utilize the feature that twin-born ON and OFF events will simultaneously arise on the bilateral side of the powerlines. We verified our algorithm in a simulated powerlines inspection scenario with background noise, it outperforms the SOTA algorithm in robustness. Surprisingly, we found that the relative motion type between UAV and the target (e.g., powerlines) is strongly correlated with the statistical asymmetry of the ON/OFF events, which provides a modal of visual cues for motion estimation in other robotic tasks and may shed a light on the explanation of why ON/OFF neural mechanism exists in numerous animals motion vision systems.

Coupled dynamic response and energy conversion characteristics of 10 MW floating vertical axis wind turbine with different configurations

Vertical axis wind turbines (VAWTs) are superior because they have compact structure, good wind adaptability and strong scalability. The coupling dynamic response mechanisms between different configurations of wind turbines and floating platforms are different. Based on the CFD method, dynamic fluid body interaction (DFBI), overlapping grid and dynamic grid techniques are used for numerical simulations. The force characteristics and self-starting features of H-type and Φ-type VAWTs are compared. The aerodynamic performance and motion response of the floating VAWT (FVAWT) are studied under different tip-speed ratios (TSR) and aspect ratios (η). The results show that the power coefficient (Cp) of H-type and Φ-type FVAWTs reaches the peak when TSR = 6 and TSR = 7, respectively. The optimal η for both is 1.2. The H-type FVAWT improves the Cp by 34.3% compared to Φ-type FVAWT. H-type FVAWT has a large thrust and excellent stability. The Φ-type FVAWT requires less initial thrust, and the self-starting performance is 12% superior to H-type FVAWT. With the increase of TSR and η, the heave motion of both FVAWTs is almost unaffected, but the pitch motion sensitivity is stronger. The heave amplitude of H-type FVAWT is 282% larger than Φ-type FVAWT, which has a gain effect on energy conversion. The Φ-type FVAWT has better safety. The strengthened structure of Φ-type VAWT has a noticeable impact on velocity and vortex distribution. In addition, the aerodynamic and hydrodynamic performance of the FVAWT is improved.

Stability of granular media impacts morphological characteristics under different impact conditions

Abstract In planetary surfaces, oblique impact events are commonplace, and their study holds significant importance for understanding planetary impact processes and aiding in the design of landers and impactors. Current research predominantly focuses on simplified models to study the force and motion under vertical impact craters in terms of scale and impact loading. For oblique impacts, investigations have primarily concentrated on the final crater shape. However, the specific influence of impact load motion on particle bed movement and the precise impact angle’s effect on the ultimate crater shape during the impact process remain unclear. In this study, we used a custom-built oblique impact experimental setup to analyze changes in the velocity field of the particle bed and the horizontal movement of the impact load. Using quasi-static region to assess ellipticity, we aimed to reveal the state of particle movement during oblique impacts and explore the impact of impact angles and energies on crater formation. The results indicate that under large impact angles, the obliquely acquired kinetic energy is minimal, leading to a predominant static point source movement of the particle bed. At higher energy levels, the impact load primarily excavates downward, resulting in the formation of circular impact craters. These findings underscore the sensitivity of particle bed motion to impact angles, making it a crucial metric for assessing the impact of oblique angles on final crater morphology.

Alterations in neural activation in the ventral frontoparietal network during complex magnocellular stimuli in developmental dyslexia associated with READ1 deletion

BackgroundAn intronic deletion within intron 2 of the DCDC2 gene encompassing the entire READ1 (hereafter, READ1d) has been associated in both children with developmental dyslexia (DD) and typical readers (TRs), with interindividual variation in reading performance and motion perception as well as with structural and functional brain alterations. Visual motion perception -- specifically processed by the magnocellular (M) stream -- has been reported to be a solid and reliable endophenotype of DD. Hence, we predicted that READ1d should affect neural activations in brain regions sensitive to M stream demands as reading proficiency changes.MethodsWe investigated neural activations during two M-eliciting fMRI visual tasks (full-field sinusoidal gratings controlled for spatial and temporal frequencies and luminance contrast, and sensitivity to motion coherence at 6%, 15% and 40% dot coherence levels) in four subject groups: children with DD with/without READ1d, and TRs with/without READ1d.ResultsAt the Bonferroni-corrected level of significance, reading skills showed a significant effect in the right polar frontal cortex during the full-field sinusoidal gratings-M task. Regardless of the presence/absence of the READ1d, subjects with poor reading proficiency showed hyperactivation in this region of interest (ROI) compared to subjects with better reading scores. Moreover, a significant interaction was found between READ1d and reading performance in the left frontal opercular area 4 during the 15% coherent motion sensitivity task. Among subjects with poor reading performance, neural activation in this ROI during this specific task was higher for subjects without READ1d than for READ1d carriers. The difference vanished as reading skills increased.ConclusionsOur findings showed a READ1d-moderated genetic vulnerability to alterations in neural activation in the ventral attentive and salient networks during the processing of relevant stimuli in subjects with poor reading proficiency.

Prediction of sensorimotor contingencies generates saccadic omission

With every movement of our eyes, the visual receptors in the retina are swiped across the visual scene. Saccades are the fastest and most frequent movements we perform, yet we remain unaware of the self-produced visual motion. Previous research has tried to identify a dedicated suppression mechanism that either actively or passively cancels vision at the time of saccades.1 Here, we investigated a novel theory, which states that saccadic omission results from habituation to the predicted sensory consequences of our own actions. We experimentally induced novel, i.e., artificial visual consequences of saccade performance by presenting gratings that were drifting faster than the flicker fusion frequency and that became visible only when participants performed saccades. We asked participants to perform more than 100 saccades in each session across these gratings to make the novel contingencies predictable for the sensorimotor system. We found that contrast sensitivity for intra-saccadic motion declined drastically after repeated exposure of such motion. The reduction in sensitivity was even specific to the saccade vector performed in habituation trials. Moreover, when subjects performed the same task in fixation, no reduction in sensitivity was observed. In a motion speed comparison task, we found that the reduction in contrast sensitivity is the consequence of silencing-predicted intra-saccadic visual motion. Our data demonstrate that the sensorimotor system selectively habituates to recurring intra-saccadic visual motion, suggesting an efficient prediction mechanism of visual stability.

AI based optimal analysis of electro-osmotic peristaltic motion of non-Newtonian fluid with chemical reaction using artificial neural networks and response surface methodology

PurposeThe present work is devoted to investigating the sensitivity analysis of the electroosmotic peristaltic motion of non-Newtonian Casson fluid with the effect of the chemical reaction and magnetohydrodynamics through the porous medium. The main focus is on flow efficiency quantities such as pressure rise per wavelength, frictional forces on the upper wall and frictional forces on the lower wall. This initiative is to bridge the existing gap in the available literature.Design/methodology/approachThe governing equations of the problem are mathematically formulated and subsequently simplified for sensitivity analysis under the assumptions of a long wavelength and a small Reynolds number. The simplified equations take the form of coupled nonlinear differential equations, which are solved using the built-in Matlab routine bvp4c. The response surface methodology and artificial neural networks are used to develop the empirical model for pressure rise per wavelength, frictional forces on the upper wall and frictional forces on the lower wall.FindingsThe empirical model demonstrates an excellent fit with a coefficient of determination reaching 100% for responses, frictional forces on the upper wall and frictional forces on the lower wall and 99.99% for response, for pressure rise per wavelength. It is revealed through the sensitivity analysis that pressure rise per wavelength, frictional forces on the upper wall and frictional forces on the lower wall are most sensitive to the permeability parameter at all levels.Originality/valueThe objective of this study is to use artificial neural networks simulation and analyze the sensitivity of electroosmotic peristaltic motion of non-Newtonian fluid with the effect of chemical reaction.

Understanding Abnormal Examination Findings During Concussion Recovery: A Retrospective Chart Review.

Physical examination findings in athletes with sport-related concussion (SRC) are not well described in the literature. The objective of this study was to describe physical examination findings during the first month following concussion in athletes, with a focus on the effect of sex, age, and time since injury. This was a retrospective electronic medical record (EMR) review of physical examination findings in 500 patients aged 6-24 who were initially seen within 15 days of SRC at a multidisciplinary outpatient academic concussion clinic between 2017 and 2019. A standardized concussion examination built in the EMR recorded mental status, cranial nerve, vestibulo-ocular motor screen, and balance findings for all patients. The primary outcome was the frequency of abnormal examination findings during the first 30 days postinjury, which was further analyzed by sex, age, and time since injury using mixed logistic regression models. The most common abnormal examination findings overall were eyes-closed single-leg stance, vestibular-ocular reflex, visual motion sensitivity, the neck examination, and eyes-closed tandem stance. Abnormal findings were more frequent in female athletes for vestibular ocular reflex and visual motion sensitivity. The frequency of abnormal findings increased with age for vestibulo-ocular reflex, visual motion sensitivity, the neck examination, convergence testing, and eyes-open single-leg stance, whereas abnormalities decreased in frequency with age for eyes-open tandem stance and tandem gait. The frequency of abnormal findings generally decreased with time over the first 4 weeks following injury. A comprehensive physical examination is pivotal for evaluation of athletes with concussion. These findings highlight high-yield components of the concussion examination and support use of these examination components as injury markers. Future work should investigate associations between physical examination findings and postconcussion symptoms and recovery outcomes. This retrospective cohort study provides Class IV evidence that neurologic examination with specifically designed clinical tests are helpful for diagnosis of traumatic brain injury in young athletes at age 6-24.

Self-powered porous polymer sensors with high sensitivity for machine learning-assisted motion and rehabilitation monitoring

Muscle contraction and relaxation inherently contains valuable information crucial for monitoring physical states, rehabilitation, and injury prevention. However, the majority of flexible wearable devices struggle to offer customizable sensors with high sensitivity, durability, and stability, resulting in suboptimal biofeedback performance. Herein, the machine learning-assisted smart motion and rehabilitation monitoring system (SMRMS) is demonstrated for full-body motion recognition and rehabilitation assessment using a designed porous triboelectric nanogenerator (TENG) array. A theoretical model of porous materials is built to demonstrate the effect mechanism of porosity on TENG output. Through pore design on the tribolayer, theoretical simulation and experimental are performed to determine the key features of porous TENG sensors with high sensitivity (1.76 kPa−1), fast response time (50 ms) and high durability (over 100,000 cycles). A ring-shaped TENG (RS-TENG) is fabricated based on the porous TENG sensor, enabling real-time recording of leg/arm force without additional attachment. By integrating the RS-TENG array with a multichannel signal acquisition system, an SMRMS is designed to capture motion information during human subjects’ exercise and rehabilitation training. These data are then fused for machine learning analytics, resulting in significantly improved accuracy in motion pattern recognition (98.75 %) and rehabilitation monitoring (100 %). The simple, precise and durable porous sensors could help mitigate the risk of excessive exercise-induced muscle injuries, expanding self-powered wearable functionalities and adaptabilities.

Comparative study between ultrasound and MR enterography in evaluation of Crohn’s disease

BackgroundCrohn’s disease is a chronic inflammatory bowel disease that can affect any part of the gut. Endoscopy is the gold standard for diagnosis, but it only assesses mucosal lesions. Magnetic resonance enterography (MRE) can assess disease presence and activity, but it has limitations such as motion sensitivity, long scan time, and high cost. Bowel sonography has been introduced as a non-invasive, practical, safe, and low-cost technique to assess disease activity and complications. In our study we aim to assess the comparability of ultrasound to MRE in evaluation of patients with Crohn’s disease, and its complications.ResultsTwenty-five patients with 38 Crohn’s disease affected segments were evaluated by bowel ultrasound (BUS) and MRI enterography (MRE), where BUS and MRE showed equivalent diagnostic performance for disease detection and localization (97.4%, 100%), for sensitivity and specificity of both modalities. Peri-mural fluid (89.5%, 94.4%) and mural stratification loss (100%, 100%) showed high sensitivity and specificity by BUS compared to MRE, while for assessment of mural vascularity, BUS showed high sensitivity and specificity for high grade vascularity (100%, 83.3%), but low sensitivity and high specificity for low and moderate vascularity (0%–62.5%, 81.8%) compared to MRE. Complications including fistulae and abscessed were all correctly identified in BUS compared to MRE.ConclusionBUS showed comparable results to MRE for identification, localization, assessment of findings related to disease activity, and complications in cases of Crohn’s disease rendering it a viable alternative to MRE.

IVOMS: Instrumented Vestibular / Ocular motor screen in healthy controls and mild traumatic brain injury

Objective Vestibular/ocular deficits occur with mild traumatic brain injury (mTBI). The vestibular/ocular motor screening (VOMS) tool is used to assess individuals post-mTBI, which primarily relies upon subjective self-reported symptoms. Instrumenting the VOMS (iVOMS) with technology may allow for more objective assessment post-mTBI, which reflects actual task performance. This study aimed to validate the iVOMS analytically and clinically in mTBI and controls.Methods Seventy-nine people with sub-acute mTBI (<12 weeks post-injury) and forty-four healthy control participants performed the VOMS whilst wearing a mobile eye-tracking on a one-off visit. People with mTBI were included if they were within 12 weeks of a physician diagnosis. Participants were excluded if they had any musculoskeletal, neurological or sensory deficits which could explain dysfunction. A series of custom-made eye tracking algorithms were used to assess recorded eye-movements.Results The iVOMS was analytically valid compared to the reference (ICC2,1 0.85–0.99) in mTBI and controls. The iVOMS outcomes were clinically valid as there were significant differences between groups for convergence, vertical saccades, smooth pursuit, vestibular ocular reflex and visual motion sensitivity outcomes. However, there was no significant relationship between iVOMS outcomes and self-reported symptoms.Conclusion The iVOMS is analytically and clinically valid in mTBI and controls, but further work is required to examine the sensitivity of iVOMS outcomes across the mTBI spectrum. Findings also highlighted that symptom and physiological issue resolution post-mTBI may not coincide and relationships need further examination.

A Proposed Mechanism for Visual Vertigo: Post-Concussion Patients Have Higher Gain From Visual Input Into Subcortical Gaze Stabilization.

Post-concussion syndrome (PCS) is commonly associated with dizziness and visual motion sensitivity. This case-control study set out to explore altered motion processing in PCS by measuring gaze stabilization as a reflection of the capacity of the brain to integrate motion, and it aimed to uncover mechanisms of injury where invasive subcortical recordings are not feasible. A total of 554 eye movements were analyzed in 10 PCS patients and nine healthy controls across 171 trials. Optokinetic and vestibulo-ocular reflexes were recorded using a head-mounted eye tracker while participants were exposed to visual, vestibular, and visuo-vestibular motion stimulations in the roll plane. Torsional and vergence eye movements were analyzed in terms of slow-phase velocities, gain, nystagmus frequency, and sensory-specific contributions toward gaze stabilization. Participants expressed eye-movement responses consistent with expected gaze stabilization; slow phases were fastest for visuo-vestibular trials and slowest for visual stimulations (P < 0.001) and increased with stimulus acceleration (P < 0.001). Concussed patients demonstrated increased gain from visual input to gaze stabilization (P = 0.005), faster slow phases (P = 0.013), earlier nystagmus beats (P = 0.003), and higher relative visual influence over the gaze-stabilizing response (P = 0.001), presenting robust effect sizes despite the limited population size. The enhanced neural responsiveness to visual motion in PCS, combined with semi-intact visuo-vestibular integration, presented a subcortical hierarchy for altered gaze stabilization. Drawing on comparable animal trials, findings suggest that concussed patients may suffer from diffuse injuries to inhibiting pathways for optokinetic information, likely early in the visuo-vestibular hierarchy of sensorimotor integration. These findings offer context for common but elusive symptoms, presenting a neurological explanation for motion sensitivity and visual vertigo in PCS.

Improved Spatiotemporal Resolution in Echocardiography Using Mixed Geometry Imaging Sequences.

Cardiac ultrasound seeks to image the most dynamic environment in the body-the moving heart. Many modern ultrasound imaging techniques address the tradeoff between spatial and temporal resolution using either narrow focused beams or with broad beam, synthetic aperture (SA) sequences that have been shown to suffer from motion artifacts. Retrospective encoding for conventional ultrasound sequences (REFoCUS) unifies the processing of these various geometric sequences, but the motion sensitivity of this approach has yet to be investigated. We hypothesize that a "mixed sequence" enabled by the REFoCUS method incorporating several beam geometries may better resolve cardiac motion over a wide field of view (FOV) and at a high frame rate. First, the motion sensitivity of REFoCUS was evaluated in simulation for several focused and broad transmit profiles. Focused transmissions resolve both lateral and axial motion much more effectively than broad transmissions, with performance similar to conventional beamforming techniques. Second, a mixed sequence was designed that insonifies the full field-of-view with plane wave (PW) transmissions and key moving targets with focused transmissions. This mixed sequence was tested in simulation and in vivo and was used to image the heart as well as the liver, a low-motion control. By combining a sparse PW sequence ( n=60 ) with a small group of targeted focused transmissions ( n = 10), the anterior mitral valve leaflet (AML) at its peak observed velocity was better resolved. We believe that mixed sequences have strong potential to resolve cardiac motion at clinically relevant frame rates.

Visual and vestibular motion perception in persistent postural-perceptual dizziness (PPPD)

Persistent postural-perceptual dizziness (PPPD) is a chronic disorder of perceived unsteadiness. Symptoms can be exacerbated in visually complex stationary or moving environment. Visual dependence and increased motion sensitivity are predictors for PPPD but its pathophysiology remains unknown. We hypothesized an abnormal sensory–perceptual scaling mechanism in PPPD and tested visual- and vestibular perceptional thresholds in 32 patients and 28 age-matched healthy control subjects (HC). All participants showed normal vestibular function tests on quantitative testing. Visual motion coherence thresholds were assessed by random dot kinetomatograms. Vestibular perceptional thresholds of egomotion were assessed by binaural galvanic vestibular stimulation (GVS) and passive chair rotation around an earth-vertical axis. Chair rotation trials were contrasted with no-motion (sham) stimulus trials. Mean thresholds of visual motion perception were higher in patients compared to HC. The perception threshold of GVS was lower in patients but the threshold of correctly perceived egomotion during chair rotation did not differ. Interestingly, the number of trials with correct perception in the no-motion condition increased with the threshold of correct responses for rotatory egomotion in patients. Unlike expected, PPPD patients required more coherently moving random dots than HC to perceive visual motion. A poorer complex visual motion recognition, e.g., traffic visual stimuli, may increase anxiety and levels of uncertainty as visuomotor reactions might occur delayed. The vestibular rotatory perception threshold predicted the probability of making false assignments in the sham condition in PPPD, i.e., patients who readily recognize the correct egomotion direction are prone to perceive egomotion in the no-motion condition. As this relation was not found in healthy subjects, it may reflect an abnormal sensory–perceptual scaling feature of PPPD.

Field Evaluation of an Autonomous, Low-Power Eddy Covariance CO2 Flux System for the Marine Environment

Abstract Eddy covariance (EC) air–sea CO2 flux measurements have been developed for large research vessels, but have yet to be demonstrated for smaller platforms. Our goal was to design and build a complete EC CO2 flux package suitable for unattended operation on a buoy. Published state-of-the-art techniques that have proven effective on research vessels, such as airstream drying and liquid water rejection, were adapted for a 2-m discus buoy with limited power. Fast-response atmospheric CO2 concentration was measured using both an off-the-shelf (“stock”) gas analyzer (EC155, Campbell Scientific, Inc.) and a prototype gas analyzer (“proto”) with reduced motion-induced error that was designed and built in collaboration with an instrument manufacturer. The system was tested on the University of New Hampshire (UNH) air–sea interaction buoy for 18 days in the Gulf of Maine in October 2020. The data demonstrate the overall robustness of the system. Empirical postprocessing techniques previously used on ship-based measurements to address motion sensitivity of CO2 analyzers were generally not effective for the stock sensor. The proto analyzer markedly outperformed the stock unit and did not require ad hoc motion corrections, yet revealed some remaining artifacts to be addressed in future designs. Additional system refinements to further reduce power demands and increase unattended deployment duration are described.

Insights on Using Time-of-Flight Camera for Recovering Cardiac Pulse From Chest Motion in Depth Videos.

In this article, we introduce a novel use of depth camera to extract cardiac pulse signal from human chest area, in which the depth information is obtained from a near infrared sensor using time-of-flight technology. We successfully isolate weak chest motion due to heartbeat by processing a sequence of depth images without raising privacy concern. We discuss motion sensitivity in depth video with examples from actuator simulation and human chest motion. Compared to other imaging modalities, the depth image intensity can be directly used for micromotion reconstruction. To deal with the challenges of recovering heartbeat from the chest area, we develop a set of coherent processing techniques to suppress the unwanted motion interference from breathing motion and involuntary body motion and eventually obtain clean cardiac pulse signal. We, thus, derive inter-beat-interval, showing high consistency to the contact photoplethysmography. Additionally, we develop a graphical interpretation of the most and the less pulsatile principal components in eigen space. For validation, we test our method on ten healthy human subjects with different resting heart rates. More importantly, we conduct a set of experiments to study the robustness and weakness of our methods, including extended range, multi-subject, thickness of clothes and generation to other measurement site.

The Role of Motion Sensitivity and Headaches on Vestibular Rehabilitation Outcomes in Pediatric Vestibular Migraines.

To determine the utility of the motion sensitivity quotient (MSQ) in diagnosing pediatric vestibular migraine (VM) and to characterize the role of motion sensitivity and headache control on vestibular rehabilitation (VR) outcomes in pediatric VM. Retrospective cohort analysis. Pediatric tertiary referral center. Children (≤18 years old) with dizziness who completed vestibular testing from January 2016 to August 2022, diagnosed with either VM or another vestibular disorder. VR, which included MSQ testing. Initial MSQ, number and duration of vestibular physical therapy (PT) sessions, PT goals met, and posttreatment MSQ. Two hundred fifty-seven patients met study criteria. MSQ was not a reliable diagnostic marker in pediatric VM as there was no difference in initial MSQ between VM and non-VM patients (9.4 vs. 7.8 in non-VM, p = 0.014). Both VM (n = 116) and non-VM (n = 141) patients demonstrated significant improvement in MSQ after VR (p = 0.004). However, VM patients tended to be less likely to meet at least one PT goal (60 vs. 77% in non-VM, p = 0.016, d = 0.37), although not significant. VM patients with more frequent headaches had significantly higher initial MSQ (p = 0.008). VM patients with more frequent headaches or higher initial MSQ tended to require increased number and longer duration of VR (small/medium effect size although not statistically significant after Bonferroni correction). VR is an effective treatment for both VM and non-VM pediatric patients. VM patients, especially those with severe motion sensitivity or poorly controlled headaches, may be less responsive to VR and may require increased frequency and duration of VR. Our findings propose the importance of counseling pediatric patients with severe motion sensitivity or uncontrolled migraines regarding realistic expectations of their VR course.