Head Roll Research Articles

Upright BPPV Protocol: Feasibility of a New Diagnostic Paradigm for Lateral Semicircular Canal Benign Paroxysmal Positional Vertigo Compared to Standard Diagnostic Maneuvers.

Background: The diagnosis of benign paroxysmal positional vertigo (BPPV) involving the lateral semicircular canal (LSC) is traditionally entrusted to the supine head roll test, also known as supine head yaw test (SHYT), which usually allows identification of the pathologic side and BPPV form (geotropic vs. apogeotropic). Nevertheless, SHYT may not always allow easy detection of the affected canal, resulting in similar responses on both sides and intense autonomic symptoms in patients with recent onset of vertigo. The newly introduced upright head roll test (UHRT) represents a diagnostic maneuver for LSC-BPPV, supplementing the already-known head pitch test (HPT) in the sitting position. The combination of these two tests should enable clinicians to determine the precise location of debris within LSC, avoiding disturbing symptoms related to supine positionings. Therefore, we proposed the upright BPPV protocol (UBP), a test battery exclusively performed in the upright position, including the evaluation of pseudo-spontaneous nystagmus (PSN), HPT and UHRT. The purpose of this multicenter study is to determine the feasibility of UBP in the diagnosis of LSC-BPPV.Methods: We retrospectively reviewed the clinical data of 134 consecutive patients diagnosed with LSC-BPPV. All of them received both UBP and the complete diagnostic protocol (CDP), including the evaluation of PSN and data resulting from HPT, UHRT, seated-supine positioning test (SSPT), and SHYT.Results: A correct diagnosis for LSC-BPPV was achieved in 95.5% of cases using exclusively the UBP, with a highly significant concordance with the CDP (p < 0.000, Cohen's kappa = 0.94), regardless of the time elapsed from symptom onset to diagnosis. The concordance between UBP and CDP was not impaired even when cases in which HPT and/or UHRT provided incomplete results were included (p < 0.000). Correct diagnosis using the supine diagnostic protocol (SDP, including SSPT + SHYT) or the sole SHYT was achieved in 85.1% of cases, with similar statistical concordance (p < 0.000) and weaker strength of relationship (Cohen's kappa = 0.80).Conclusion: UBP allows correct diagnosis in LSC-BPPV from the sitting position in most cases, sparing the patient supine positionings and related symptoms. UBP could also allow clinicians to proceed directly with repositioning maneuvers from the upright position.

Delayed Development of Head Control and Rolling in Infants With Tracheostomies.

Objective: Advances in neonatal care lead to an increased survival rate of critically ill babies. Infantile tracheostomies are not uncommon. However, only a few studies have addressed the effect of infant tracheostomy on early motor function. By comparing the scores of the Gross Motor Function Measure-88 (GMFM) on head control and rolling of infants with and without tracheostomies, the authors aimed to evaluate the effect of infant tracheostomy on early motor development.Methods: Medical records and the GMFM of subjects were retrospectively reviewed. Thirty-three infants with tracheostomies and 132 infants without tracheostomies were matched by gestational age, birth weight, and corrected age when the GMFM was performed using propensity score matching. GMFM scores in head control and rolling in different positions were compared by using generalized estimating equation (GEE).Results: Infants with tracheostomy showed lower values for head control in the supine position and in the pull to sit maneuver in multivariate GEE (p = 0.008, 0.004, respectively). However, the results of head control in a prone position and head lift while the examiner held the thorax showed no difference between the groups. Rolling from prone to supine was delayed in the infants with tracheostomy (p = 0.002), while rolling from supine to prone was not delayed compared to the non-tracheostomized group. More than half (54%) of the tracheostomy group scored better in rolling from a prone to supine position than in head control in supine position, which was a higher ratio compared to the non-tracheostomy group (p = 0.00).Conclusions: Tracheostomy seems to influence early motor development in infants. In particular, head control skills related to neck flexor muscle activation and rolling from prone to supine were delayed. Interventions may be required to facilitate these activities.

The Anatomical and Physiological Basis of Clinical Tests of Otolith Function. A Tribute to Yoshio Uchino.

Otolithic receptors are stimulated by gravitoinertial force (GIF) acting on the otoconia resulting in deflections of the hair bundles of otolithic receptor hair cells. The GIF is the sum of gravitational force and the inertial force due to linear acceleration. The usual clinical and experimental tests of otolith function have used GIFs (roll tilts re gravity or linear accelerations) as test stimuli. However, the opposite polarization of receptors across each otolithic macula is puzzling since a GIF directed across the otolith macula will excite receptors on one side of the line of polarity reversal (LPR at the striola) and simultaneously act to silence receptors on the opposite side of the LPR. It would seem the two neural signals from the one otolith macula should cancel. In fact, Uchino showed that instead of canceling, the simultaneous stimulation of the oppositely polarized hair cells enhances the otolithic response to GIF—both in the saccular macula and the utricular macula. For the utricular system there is also commissural inhibitory interaction between the utricular maculae in each ear. The results are that the one GIF stimulus will cause direct excitation of utricular receptors in the activated sector in one ear as well as indirect excitation resulting from the disfacilitation of utricular receptors in the corresponding sector on the opposite labyrinth. There are effectively two complementary parallel otolithic afferent systems—the sustained system concerned with signaling low frequency GIF stimuli such as roll head tilts and the transient system which is activated by sound and vibration. Clinical tests of the sustained otolith system—such as ocular counterrolling to roll-tilt or tests using linear translation—do not show unilateral otolithic loss reliably, whereas tests of transient otolith function [vestibular evoked myogenic potentials (VEMPs) to brief sound and vibration stimuli] do show unilateral otolithic loss. The opposing sectors of the maculae also explain the results of galvanic vestibular stimulation (GVS) where bilateral mastoid galvanic stimulation causes ocular torsion position similar to the otolithic response to GIF. However, GVS stimulates canal afferents as well as otolithic afferents so the eye movement response is complex.

Improved feasibility of astronaut short-radius artificial gravity through a 50-day incremental, personalized, vestibular acclimation protocol

The “Coriolis” cross-coupled (CC) illusion has historically limited the tolerability of utilizing fast-spin rate, short-radius centrifugation for in-flight artificial gravity. Previous research confirms that humans acclimate to the CC illusion over 10 daily sessions, though the efficacy of additional training is unknown. We investigated human acclimation to the CC illusion over up to 50 daily sessions of personalized, incremental training. During each 25-min session, subjects spun in yaw and performed roll head tilts approximately every 30 s, reporting the presence or absence of the illusion while rating motion sickness every 5 min. Illusion intensity was modulated by altering spin rate based upon subject response, such that the administered stimulus remained near each individual’s instantaneous illusion threshold. Every subject (n = 11) continued to acclimate linearly to the CC illusion during the investigation. Subjects acclimated at an average rate of 1.17 RPM per session (95% CI: 0.63–1.71 RPM per session), with the average tolerable spin rate increasing from 1.4 to 26.2 RPM, corresponding to a reduction in required centrifuge radius from 456.6 to 1.3 m (to produce loading of 1 g at the feet). Subjects reported no more than slight motion sickness throughout their training (mean: 0.92/20, 95% CI: 0.35–1.49/20). We applied survival analysis to determine the probability of individuals reaching various spin rates over a number of training days, providing a tolerability trade parameter for centrifuge design. Results indicate that acclimation to a given, operationally relevant spin rate may be feasible for all subjects if given a sufficient training duration.

The effect of head roll and soft surface on Virtual SVV in healthy subjects: A normalization study

Objective: The utricle is a crucial structure for a sense of gravity, but the contribution of proprioceptive receptors is also essential. This study aimed to measure the effect of head roll and soft surface on subjective visual vertical (SVV) in healthy subjects to determine the effect of neck and plantar proprioceptive inputs.

The Influence of Mechanical Treatment Type on the Tribological Properties of Flame Sprayed Ni-5% Al-15% Al2O3 Composite Coatings

During operation of marine pumps, one of the most common disability is tribological wear of shaftneck cooperating with the gland. In the practice, worn shafts are exchanged for new or are regenerated bychromium plating, padding or thermally sprayed of ceramic coatings, mainly Al2O3. In this article, the use offlame sprayed Ni-5%Al-15%Al2O3 composite coatings were proposed. The surfaces of coatings by turning,grinding are burnishing treatments were formed. Tribological properties of composite materials are dependent onthe proportion and size of the reinforcing phase particles contained in a metal matrix. A reinforcement compositewith very small dimensions and the amounts may result in increased wear and increase the coefficient of friction.It is therefore important to check whether the advisable of phase composition will not adversely affect the wearof the composite and the cooperating the part. The presence of a 15% volume fraction of the alumina particles onthe selected tribological properties of the Ni-5%Al matrix composite coatings were evaluated. In order to assessthe effect of the applied tapes of finishing on wear of composite coatings, the tribological tests were performedon the "T05" tribometer with head roll- piece type. It has been found that the burnishing favors a lower wear ofcomposite coating and the cooperating element compared to the coatings after turning treatments. At the sametime observed more than ten times less wear intensity of composite coatings in the initial time of friction, whichmay indicate a shorter time needed to running-in of cooperating elements.

Upright head roll test: A new contribution for the diagnosis of lateral semicircular canal benign paroxysmal positional vertigo.

Diagnosing the affected side in Benign Paroxysmal Positional Vertigo (BPPV) involving the Lateral Semicircular Canal (LSC) is often challenging and uncomfortable in patients with recent onset of vertigo and intense autonomic symptoms. The Minimum Stimulus Strategy (MSS) aims to diagnose side and canal involved by BPPV causing as little discomfort as possible to the patient. The strategy applied for LSC-BPPV includes the evaluation of pseudo-spontaneous nystagmus and oculomotor responses to the Head Pitch Test (HPT) in upright position, to the seated-supine test and to the Head Yaw Test (HYT) while supine. Matching data obtained by these tests enables clinicians to diagnose the affected side in LSC-BPPV. The purpose of this preliminary study is to propose a new diagnostic test for LSC-BPPV complimentary to the HPT, the Upright Head Roll Test (UHRT), to easily determine the affected ear and the involved arm in the sitting position and to evaluate its efficiency. Our results suggest that the UHRT can increase the sensitivity of the MSS without resorting to the HYT, thus reducing patient’s discomfort.

A Matlab-based toolbox for characterizing behavior of rodents engaged in string-pulling.

String-pulling by rodents is a behavior in which animals make rhythmical body, head, and bilateral forearm as well as skilled hand movements to spontaneously reel in a string. Typical analysis includes kinematic assessment of hand movements done by manually annotating frames. Here, we describe a Matlab-based software that allows whole-body motion characterization using optical flow estimation, descriptive statistics, principal component, and independent component analyses as well as temporal measures of Fano factor, entropy, and Higuchi fractal dimension. Based on image-segmentation and heuristic algorithms for object tracking, the software also allows tracking of body, ears, nose, and forehands for estimation of kinematic parameters such as body length, body angle, head roll, head yaw, head pitch, and path and speed of hand movements. The utility of the task and software is demonstrated by characterizing postural and hand kinematic differences in string-pulling behavior of two strains of mice, C57BL/6 and Swiss Webster.

Reaching around obstacles accounts for uncertainty in coordinate transformations

When reaching to a visual target, humans need to transform the spatial target representation into the coordinate system of their moving arm. It has been shown that increased uncertainty in such coordinate transformations, for instance, when the head is rolled toward one shoulder, leads to higher movement variability and influence movement decisions. However, it is unknown whether the brain incorporates such added variability in planning and executing movements. We designed an obstacle avoidance task in which participants had to reach with or without visual feedback of the hand to a visual target while avoiding collisions with an obstacle. We varied coordinate transformation uncertainty by varying head roll (straight, 30° clockwise, and 30° counterclockwise). In agreement with previous studies, we observed that the reaching variability increased when the head was tilted. Indeed, head roll did not influence the number of collisions during reaching compared with the head-straight condition, but it did systematically change the obstacle avoidance behavior. Participants changed the preferred direction of passing the obstacle and increased the safety margins indicated by stronger movement curvature. These results suggest that the brain takes the added movement variability during head roll into account and compensates for it by adjusting the reaching trajectories.NEW & NOTEWORTHY We show that changing body geometry such as head roll results in compensatory reaching behaviors around obstacles. Specifically, we observed head roll causes changed preferred movement direction and increased trajectory curvature. As has been shown before, head roll increases movement variability due to stochastic coordinate transformations. Thus these results provide evidence that the brain must consider the added movement variability caused by coordinate transformations for accurate reach movements.

Lateral control strategy based on head movement responses for motion sickness mitigation in autonomous vehicle

Passengers are more susceptible to motion sickness (MS) than the drivers because during cornering, they tilt their heads according to lateral acceleration direction, while the drivers tilt their heads against it. During slalom driving, high lateral acceleration that resulted from inappropriate wheel’s turning will increase the severity level of MS as it contributes to a larger passenger’s head roll angle towards the lateral acceleration direction. Thus, for an autonomous vehicle, it is necessary to design a smooth lateral control to obtain appropriate wheel angle to prevent high lateral acceleration. This study proposes an inner-loop lateral control strategy which utilized head roll angle as the controlled variable to generate corrective wheel angle to reduce the lateral acceleration. Firstly, an estimation model of driver’s and passenger’s head roll angle is developed by radial basis function network method based on the correlation between lateral acceleration and occupant’s head roll angle. The driver’s and passenger’s models are considered as the reference and the controlled subject, respectively. Secondly, a fuzzy logic controller is adopted to generate corrective wheel angle based on the head roll angle responses. The reduction of the lateral acceleration caused by the corrective wheel angle minimized the passenger’s head roll angle and hence mitigated their MS level. Simulation results show 3.25% and 10.86% reduction of motion sickness incidence in a single lap and ten laps after the proposed control strategy is applied. It is expected that the proposed control strategy will contribute to the MS mitigation study in autonomous vehicle field.

Impact of visual signals on axial segmental control during walking in patients with vestibular disorder and healthy persons

Head and trunk control during standing in patients with vestibular disorder may depend on intact visual signal to override vestibular disturbance. It is unknown if such process during walking would change. Therefore, the aims of this study were to quantify (1) head and trunk control in healthy participants (HPs) and patients with unilateral vestibular hypofunction (UVH) during walking with and without visual manipulation; and (2) the correlation/association between vestibular function and head/trunk control during walking with visual manipulation in patients. Seventeen UVH patients and 15 HPs completed all the tests. They participated in the caloric test, which was used to examine vestibular function, and walked on a treadmill with and without visual manipulation. Head and trunk angular displacement and velocity were primary outcome measures, deviation of center of mass and step variability were secondary. Head roll angular displacement (7.38° ± 1.38 [mean ± SE] v.s. 12.95° ± 1.48, p = 0.004) and head-trunk correlation (in the pitch/sagittal plane: 0.22 ± 0.05 v.s. 0.38 ± 0.05, roll/frontal plane: 0.35 ± 0.06 v.s. 0.55 ± 0.06, p < 0.05) were significantly lower in patients compared to HPs. Head pitch angular velocity (8.58°/s ± 2.17 v.s. 14.23°/s ± 1.22, p = 0.026) and step width variability (0.075 ± 0.010 v.s. 0.083 ± 0.009, p = 0.04) increased with visual manipulation only in patients. No significant correlation/association was found between vestibular function and head/trunk control. Lower head-trunk correlation in patients suggests an independent head-trunk control strategy in response to vestibular impairment. Visual input could be used by patients to compensate for vestibular disturbance for head control and foot placement. Severe UVH may not lead to worse postural control compared to mild disorder.

Objective Analysis of Neck Muscle Boundaries for Cervical Dystonia Using Ultrasound Imaging and Deep Learning.

To provide objective visualization and pattern analysis of neck muscle boundaries to inform and monitor treatment of cervical dystonia. We recorded transverse cervical ultrasound (US) images and whole-body motion analysis of sixty-one standing participants (35 cervical dystonia, 26 age matched controls). We manually annotated 3,272 US images sampling posture and the functional range of pitch, yaw, and roll head movements. Using previously validated methods, we used 60-fold cross validation to train, validate and test a deep neural network (U-net) to classify pixels to 13 categories (five paired neck muscles, skin, ligamentum nuchae, vertebra). For all participants for their normal standing posture, we segmented US images and classified condition (Dystonia/Control), sex and age (higher/lower) from segment boundaries. We performed an explanatory, visualization analysis of dystonia muscle-boundaries. For all segments, agreement with manual labels was Dice Coefficient (64 ± 21%) and Hausdorff Distance (5.7 ± 4mm). For deep muscle layers, boundaries predicted central injection sites with average precision 94 ± 3%. Using leave-one-out cross-validation, a support-vector-machine classified condition, sex, and age from predicted muscle boundaries at accuracy 70.5%, 67.2%, 52.4% respectively, exceeding classification by manual labels. From muscle boundaries, Dystonia clustered optimally into three sub-groups. These sub-groups are visualized and explained by three eigen-patterns which correlate significantly with truncal and head posture. Using US, neck muscle shape alone discriminates dystonia from healthy controls. Using deep learning, US imaging allows online, automated visualization, and diagnostic analysis of cervical dystonia and segmentation of individual muscles for targeted injection.

ОРИЕНТАЦИЯ В ПРОСТРАНСТВЕ, ВЕСТИБУЛЯРНАЯ ФУНКЦИЯ И ЗРИТЕЛЬНОЕСЛЕЖЕНИЕ ВУСЛОВИЯХ ИЗМЕНЕННОЙ ГРАВИТАЦИОННОЙ СРЕДЫ

The paper reports results of the author's sensorimotor physiology studies made under the guidance of I.B.Kozlovskaya. The vestibular function and ocular tracking tests were performed by more than 100 cosmonauts prior to and after long-term missions to the Mir and International space station. Fifty two of them implemented these tests between mission days 129 to 215. We studies orientation illusions, spontaneous eye movements, static vestibulo-ocular response to head turns (static otolith-cervical reflex), dynamic vestibulo-ocular reactions to the head roll about the body axis, precision of fixational eye movements, and smooth tracking. Results of testing in the real changed gravity were compared with the data from 7 to 21-day simulation studies in horizontal dry immersion. The tests revealed 4 forms of vestibular disorders characterized by disturbances of spatial perception, orientation illusions, inversions of vection illusions, weakening of static and strengthening of dynamic vestibulo-ocular reactions, a new visual tracking strategy termed a saccadic approximation, that is the gaze approaches or tracks a target using a series of saccadic movements. In addition, the tests made it possible to specify the impact of afferentation deficit (sensory deprivation) on accuracy of ocular and ocular-manual tracking and validate additional sensory stimulation as a method to counteract the effects of sensory deprivation in real and simulated microgravity.

Lateral head flexion as a noncoplanar solution for ring gantry stereotactic radiosurgery.

Ring gantry radiotherapy devices are often limited to deliver beams in the axial plane, severely limiting beam entrance angles and rendering noncoplanar beam delivery impossible. However, a ring gantry geometry greatly simplifies delivery machines and increases the efficiency of treatment with the potential to decrease the overall costs of radiotherapy. This study explores the use of lateral head flexion in order to increase beam entrance angles and extend the available solid angle space for a ring gantry stereotactic radiosurgery (SRS) application. A 1.5T magnetic resonance imaging scanner was used to scan seven healthy volunteers at three different head positions: a neutral position, a left lateral flexion position and a right lateral flexion position. The lateral flexion scans were co-registered to the neutral head position scan using rigid registration and extracting the rotational transformation. The head pitch, roll, and yaw were computed for each registration to evaluate the natural range of motion for all volunteers. A ring gantry plan geometry was used to generate two sets of single fraction SRS plans (21Gy): one coplanar set for head neutral scans, and a three-arc plan set using the head neutral and lateral head flexion scans. The conformity index (CI), intermediate dose fall-off (R50), low dose spillage (R10), and gradient measure (GM) were used to evaluate both sets of plans. The treatment plans were generated for a ring-gantry linear accelerator (linac) (Varian Halcyon 2.0) as well as radiosurgery linac (Varian Edge) for comparison. The average pitch, yaw, and roll for the lateral head flexion scans were 4.1°±4.7°, 16.9°±3.7°, and 2.5°±4.9° for the right flexion and 4.9°±4.3°, 14.0°±3.7° and 2.8°±5.4° for left flexion. When comparing the head flexion technique with a fully coplanar geometry, the ring gantry plans showed an average improvement in CI of 7.3% (1.46±0.25 vs 1.36±0.28), a decrease of 13% in R50 (5.46±1.14 vs 4.78±1.12), a decrease of 32% in R10 (85.7±20.3 vs 58.2±15.1), and a decrease of 7.8% in GM (0.53±0.05 vs 0.49±0.04). The Edge plans showed an average improvement in CI of 3.0% (1.49±0.26 vs 1.45±0.25), a decrease of 6.8% in R50 (5.19±1.03 vs 4.82±0.83), a decrease of 29% in R10 (84.1±16.3 vs 59.9±12.5), and a decrease of 5.0% in GM (0.50±0.04 vs 0.47±0.03). Lateral head flexion was shown to increase beam entrance angles considerably improving plan conformity and normal tissue sparing in this pilot study of seven sets of plans. Rigid registrations demonstrated each lateral flexion to be analogous to a 15° couch kick. The head flexion technique outlined here was shown to be a feasible solution for SRS treatments being delivered on ring gantry devices.

Differences in the Head Roll Test, Bow and Lean Test, and Null Plane between Persistent and Transient Geotropic Direction-Changing Positional Nystagmus.

Background: Persistent geotropic direction-changing positional nystagmus (DCPN) has the characteristics of cupulopathy, but its underlying pathogenesis is not known. We investigated the relationship of the results of the head roll test, bow and lean test, and side of the null plane between persistent and transient geotropic DCPN to determine the lesion side of persistent geotropic DCPN and understand its mechanism. Methods: We enrolled 25 patients with persistent geotropic DCPN and 41 with transient geotropic DCPN. We compared the results of the head roll test, bow and lean test, and side of the null plane between the two groups. Results: The rates of bowing and leaning nystagmus were significantly higher in the persistent DCPN group. Only 16.0% of the persistent DCPN patients had stronger nystagmus in the head roll test and the null plane on the same side. The rates of the direction of bowing nystagmus in the bow and lean test and stronger nystagmus in the head roll test on the same side were also significantly lower in persistent DCPN than in transient DCPN. Conclusion: It was difficult to determine the lesion side in persistent geotropic DCPN using the direction of stronger nystagmus in the head roll test and null plane when the direction of the stronger nystagmus and null plane were opposite. Further study is needed to understand the position of the cupula according to head rotation and the anatomical position in persistent geotropic DCPN.

Determining Potential Benefits of Volumetric Image Matching in Radiation Therapy

Accurate daily setup of head and neck cancer patients receiving radiation therapy is a high priority due to the presence of critical structures near the target volume. It is generally accepted that volumetric image matching is superior to projection image matching in detecting head roll about the axial plane, however it increases treatment time and peripheral dose. The goal of this study is to quantify the difference in patient setup error inherent to projection and volumetric image matching.

Nusinersen for Type 1 Spinal Muscular Atrophy: A Father's Perspective.

* Abbreviations: HINE-2 — : Hammersmith Infant Neurologic Examination, section 2 — SMA — : spinal muscular atrophy We thought our younger son was healthy at birth, and we had high hopes for his future. His weak movements and excessive fussiness raised our concerns, leading to an unsuspected, devastating diagnosis of type 1 spinal muscular atrophy (SMA). The US Food and Drug Administration had recently approved nusinersen, the first disease-modifying treatment for SMA, but its supporting evidence and steep list price made the drug controversial. We made the decision to treat him, despite limited available information. My roles of father and physician soon became inextricably linked; pulse oximetry alarms needed attention at home like in the emergency department, and sometimes the commute from work to our son’s bedside involved only a brief elevator ride to the PICU. This experience offered an unexpected perspective on the benefits and costs of nusinersen therapy for type 1 SMA. Consider the patient impact of 1 end point of the ENDEAR trial1 (identifier NCT02193074 at www.clinicaltrials.gov): motor-milestone response, assessed by using the Hammersmith Infant Neurologic Examination, section 2 (HINE-2). The HINE-2 quantifies infant motor development by assigning scores to various abilities,2 including head control, rolling, and sitting. The use of this end point was motivated by the natural history of type 1 SMA; children rarely gain new motor milestones after symptom onset, and loss of previously achieved milestones is expected instead.3 The value of motor-milestone response may not be self-evident, but for our son, what seem like minor changes in the HINE-2 led to major improvements in function. Our son fit the population enrolled in the ENDEAR trial, … Address correspondence to Nathan R. Hoot, MD, PhD, Department of Emergency Medicine, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin St, 4th Floor JJL, Houston, TX 77030. E-mail: nathan.r.hoot{at}uth.tmc.edu

Radial basis function neural network for head roll prediction modelling in a motion sickness study

&lt;span&gt;Motion Sickness (MS) is the result of uneasy feelings that occurs when travelling. In MS mitigation studies, it is necessary to investigate and measure the occupant’s Motion Sickness Incidence (MSI) for analysis purposes. One way to mathematically calculate the MSI is by using a 6-DOF Subjective Vertical Conflict (SVC) model. This model utilises the information of the vehicle lateral acceleration and the occupant’s head roll angle to determine the MSI. The data of the lateral acceleration can be obtained by using a sensor. However, it is impractical to use a sensor to acquire the occupant’s head roll response. Therefore, this study presents the occupant’s head roll prediction model by using the Radial Basis Function Neural Network (RBFNN) method to estimate the actual head roll responses. The prediction model is modelled based on the correlation between lateral acceleration and head roll angle during curve driving. Experiments have been conducted to collect real naturalistic data for modelling purposes. The results show that the predicted responses from the model are similar with the real responses from the experiment. In future, it is expected that the prediction model will be useful in measuring the occupant’s MSI level by providing the estimated head roll responses.&lt;/span&gt;

Perioperative vestibular assessment and testing

Vestibular disorders can be difficult to accurately diagnose and manage. A careful history and focused physical examination are typically adequate to establish a diagnosis and initiate medical treatment. Vestibular testing is an important component of the work-up, but it is particularly essential for patients being considered for surgical intervention for a vestibular disorder, where the testing can be used to more definitively confirm a suspected diagnosis and to determine baseline vestibular organ function. In this article, we will first briefly review key components of the history and physical examination of patients with vestibular complaints. We will then discuss the most commonly used vestibular tests and their role in the preoperative assessment of patients undergoing vestibular surgery, including nystagmography, caloric testing, rotary chair testing, video head impulse testing, and vestibular evoked myogenic potential testing.

The Correlation Model of Head Roll and Lateral Acceleration during Curve Driving via Hammerstein-Wiener

Generally, passengers are more prone to Motion Sickness (MS) than the drivers. The difference of their severity level of MS is due to their different head movement towards the direction of the lateral acceleration. During cornering, the passengers tend to tilt their heads according to the direction, while the drivers tends to tilt their head opposite to the direction. Based on this fact, the passengers are able to reduce their MS level if they can imitate the driver’s head movement or lessen their head tilt angle towards the direction of the lateral acceleration. However, it is easier to design MS mitigation method based on the head tilt movement strategy if the mathematical expression of their head behaviour is known beforehand. On way to derive the mathematical expression is by modelling the relationship between the occupant’s head tilt movements and the vehicle’s lateral acceleration during curve driving. Therefore, this study proposed the usage of Hammerstein-Wiener (H-W) method for the modelling purpose. Experiment is set up to obtain the naturalistic data for the modelling process. The modelling process is carried out by varying the input output nonlinearities estimators. The results show that the estimated output responses from the H-W models are similar with the real responses taken from the experiment.The derived models for both passenger and driver have 68.88% and 66.32% of Best Fit (BF) percentages. With further study, the passenger’s and driver’s models which are developed by the proposed H-W modelling strategy are expected to contribute in MS minimisation studies.