Head Rotation Research Articles

Stabilizing Mechanisms in Patients Treated Using Hill-Sachs Remplissage With Bankart Repair in Abduction-External Rotation Position.

Hill-Sachs lesion (HSL) remplissage with Bankart repair (RMBR) provides a minimally invasive solution for treating HSLs and glenoid bone defects of <25%. The infraspinatus tendon is inserted into the HSL during the remplissage process, causing the infraspinatus to shift medially, leading to an unknown effect on glenohumeral alignment during the resting abduction-external rotation (ABER) and muscle-active states. The purpose of this study was to evaluate the possible check-rein effect and muscle-active control in stabilizing the glenohumeral joint after RMBR in vivo. We hypothesized that the check-rein effect and active control would stabilize the glenohumeral joint in the ABER position in patients after RMBR. Controlled laboratory study. We included 42 participants-22 patients in group A who met the inclusion criteria after RMBR and 20 healthy participants in group B without shoulder laxity. Three-dimensional magnetic resonance imaging was performed to analyze the alignment relationship of the glenohumeral joint with and without muscular activity. Ultrasonic shear wave elastography was used to evaluate the elastic properties of the anterior capsule covered with the anterior bands of the inferior glenohumeral ligament. Patients who underwent RMBR demonstrated more posterior (-1.81 ± 1.19 mm vs -0.76 ± 1.25 mm; P = .008) and inferior (-1.05 ± 0.62 mm vs -0.45 ± 0.48 mm; P = .001) shifts of the humeral head rotation center and less anterior capsular elasticity (70.07 ± 22.60 kPa vs 84.01 ± 14.08 kPa; P = .023) than healthy participants in the resting ABER state. More posterior (-3.17 ± 0.84 mm vs -1.81 ± 1.19 mm; P < .001) and less-inferior (-0.34 ± 0.56 mm vs -1.05 ± 0.62 mm; P < .001) shifts of the humeral head rotation center and less anterior capsular elasticity (36.57 ± 13.89 kPa vs 70.07 ± 22.60 kPa; P < .001) were observed in the operative shoulder during muscle-active ABER than in resting ABER states. The check-rein effect and muscle-active control act as stabilizing mechanisms in RMBR during the ABER position. Stabilizing mechanisms in RMBR during the ABER position include the check-rein effect and muscle-active control.

Intraobserver and Interobserver Reliability of Pelvic Obliquity Measurement Methods in Patients With Idiopathic Scoliosis.

Despite the importance of the assessment of pelvic obliquity, especially in the planning of surgery, there is no consensus on the pelvic obliquity measurements. The purpose of this study is to assess the intraobserver and interobserver reliability of 4 different pelvic obliquity measuring methods in patients with idiopathic scoliosis (IS): the Osebold, O'Brien, Maloney, and Allen&Ferguson methods. A retrospective cohort of 85 posteroanterior full-spine radiographs in the standing position of patients with IS involving the pelvic obliquity was evaluated by a team of 3 raters. The same researcher recorded the curve magnitude, apical vertebral rotation, Risser grade, curve pattern, and femoral head height difference. The pelvic obliquity angle was measured using the Osebold, O'Brien, Maloney, and Allen&Ferguson methods. The same graders were asked to regrade the same radiographs after at least 1 month. The Osebold method showed the highest interobserver reliability with an ICC of 0.994 and 0.983. The Allen&Ferguson method had the lowest reliability with an ICC of 0.911 and 0.934, but all of the methods were considered having excellent reliability. The Osebold method also showed the highest intraobserver reliability, ranging from 0.909 to 0.997. The Allen&Ferguson method had the lowest intraobserver reliability, with a range of 0.741 to 0.960. Also, all observers preferred the Osebold Method. The observers reported that the Allen&Ferguson method was considered the most time-consuming method, while the least time-consuming method was specified as the Osebold method. To the best of our knowledge, this study is the first to evaluate the intraobserver and interobserver reliability of pelvic obliquity among common measurement methods in patients with idiopathic scoliosis. All methods were evaluated as having excellent to good reliability in this study, but the Osebold method is the most reliable method of measuring pelvic obliquity on a frontal view radiograph in idiopathic scoliosis. The Osebold method is easier to use as it requires only the iliac crests to be visualized. Level III-Retrospective cohort study.

Simplified Design Method of Laterally Loaded Rigid Monopiles in Cohesionless Soil

This paper presents a simplified design method for laterally loaded rigid monopiles in cohesionless soil. The proposed design method is based on a constant depth of the rotation point and a bi-linear distribution of soil lateral reaction along the embedded length of the monopile. Furthermore, a mobilization coefficient of soil resistance is introduced to quantify the magnitude of the soil reaction mobilized under a certain load level applied at the pile head. The mobilization coefficient is found to be directly related to the pile head rotation by back-analyzing test results measured from 13 laterally loaded piles in the published literature. The feasibility and reliability of the proposed design method are evaluated with another 23 laterally loaded piles, which are compiled in a database. The results show that the proposed design method yields relatively satisfactory predictions of the nonlinear load-deformation responses of these piles. Furthermore, comparison of soil lateral reaction profiles between those measured and calculated with the proposed method proves the validity of the assumed soil reaction profiles. As the mobilization coefficient is back-analyzed from piles mostly embedded in uniform ground and the pile bending and translational deformations are neglected in this study, the proposed method is suitable for monopile designs in uniform sites with medium~medium-dense sand, in which the pile bending and translational deformations can be ignored.

Servo navigators: Linear regression and feedback control for rigid-body motion correction.

Navigator-based correction of rigid-body motion reconciling high precision with minimal acquisition, minimal calibration and simple, fast processing. A short orbital navigator (2.3 ms) is inserted in a three-dimensional (3D) gradient echo sequence for human head imaging. Head rotation and translation are determined by linear regression based on a complex-valued model built either from three reference navigators or in a reference-less fashion, from the first actual navigator. Optionally, the model is expanded by global phase and field offset. Run-time scan correction on this basis establishes servo control that maintains validity of the linear picture by keeping its expansion point stable in the head frame of reference. The technique is assessed in a phantom and demonstrated by motion-corrected imaging in vivo. The proposed approach is found to establish stable motion control both with and without reference acquisition. In a phantom, it is shown to accurately detect motion mimicked by rotation of scan geometry as well as change in global B0 . It is demonstrated to converge to accurate motion estimates after perturbation well beyond the linear signal range. In vivo, servo navigation achieved motion detection with precision in the single-digit range of micrometers and millidegrees. Involuntary and intentional motion in the range of several millimeters were successfully corrected, achieving excellent image quality. The combination of linear regression and feedback control enables prospective motion correction for head imaging with high precision and accuracy, short navigator readouts, fast run-time computation, and minimal demand for reference data.

Testing the ‘differences in virtual and physical head pose’ and ‘subjective vertical conflict’ accounts of cybersickness

When we move our head while in virtual reality, display lag will generate differences in our virtual and physical head pose (known as DVP). While DVP are a major trigger for cybersickness, theories differ as to exactly how they constitute a provocative sensory conflict. Here, we test two competing theories: the subjective vertical conflict theory and the DVP hypothesis. Thirty-two HMD users made continuous, oscillatory head rotations in either pitch or yaw while viewing a large virtual room. Additional display lag was applied selectively to the simulation about the same, or an orthogonal, axis to the instructed head rotation (generating Yaw-Lag + Yaw-Move, Yaw-Lag + Pitch-Move, Pitch-Lag + Yaw-Move, and Pitch-Lag + Pitch-Move conditions). At the end of each trial: (1) participants rated their sickness severity and scene instability; and (2) their head tracking data were used to estimate DVP throughout the trial. Consistent with our DVP hypothesis, but contrary to subjective vertical conflict theory, Yaw-Lag + Yaw-Move conditions induced significant cybersickness, which was similar in magnitude to that in the Pitch-Lag + Pitch-Move conditions. When extra lag was added along the same axis as the instructed head movement, DVP was found to predict 73–76% of the variance in sickness severity (with measures of the spatial magnitude and the temporal dynamics of the DVP both contributing significantly). Ratings of scene instability were also found to predict sickness severity. Taken together, these findings suggest that: (1) cybersickness can be predicted from objective estimates of the DVP; and (2) provocative stimuli for this sickness can be identified from subjective reports of scene instability.

Comparison of the Effect of the Jaw Thrust Maneuver, Chin Lift, Head Rotation, and Tongue Protrusion on the Obstruction of Different Levels of the Upper Airway During the Drug-Induced Sleep Endoscopy: A Cross-Sectional Study.

The online version contains supplementary material available at 10.1007/s12070-023-04470-1.

Predicting occupant head displacements in evasive maneuvers; tuning and comparison of a rotational based and a translational based neck muscle controller.

Objective: Real-life car crashes are often preceded by an evasive maneuver, which can alter the occupant posture and muscle state. To simulate the occupant response in such maneuvers, human body models (HBMs) with active muscles have been developed. The aim of this study was to implement an omni-directional rotational head-neck muscle controller in the SAFER HBM and compare the bio-fidelity of the HBM with a rotational controller to the HBM with a translational controller, in simulations of evasive maneuvers. Methods: The rotational controller was developed using an axis-angle representation of head rotations, with x, y, and z components in the axis. Muscle load sharing was based on rotational direction in the simulation and muscle activity recorded in three volunteer experiments in these directions. The gains of the rotational and translational controller were tuned to minimize differences between translational and rotational head displacements of the HBM and volunteers in braking and lane change maneuvers using multi-objective optimizations. Bio-fidelity of the model with tuned controllers was evaluated objectively using CORrelation and Analysis (CORA). Results: The results indicated comparable performance for both controllers after tuning, with somewhat higher bio-fidelity for rotational kinematics with the translational controller. After tuning, good or excellent bio-fidelity was indicated for both controllers in the loading direction (forward in braking, and lateral in lane change), with CORA scores of 0.86-0.99 and 0.93-0.98 for the rotational and translational controllers, respectively. For rotational displacements, and translational displacements in the other directions, bio-fidelity ranged from poor to excellent, with slightly higher average CORA scores for the HBM with the translational controller in both braking and lane changing. Time-averaged muscle activity was within one standard deviation of time-averaged muscle activity from volunteers. Conclusion: Overall, the results show that when tuned, both the translational and rotational controllers can be used to predict the occupant response to an evasive maneuver, allowing for the inclusion of evasive maneuvers prior to a crash in evaluation of vehicle safety. The rotational controller shows potential in controlling omni-directional head displacements, but the translational controller outperformed the rotational controller. Thus, for now, the recommendation is to use the translational controller with tuned gains.

Magnetic resonance imaging-based classification of the myodural bridge complex and its influencing factors

Cerebrospinal fluid (CSF) circulation is considered the third circulation of the human body. Recently, some scholars have proposed the myodural bridge (MDB) as a novel power source for CSF flow. Moreover, the suboccipital muscles can exert a driving force on the CSF via the MDB. This hypothesis is directly supported by head rotation and nodding movements, which can affect CSF circulation. The MDB has been validated as a normal structure in humans and mammals. In addition, the fusion of MDB fibers of different origins that act in concert with each other forms the MDB complex (MDBC). The MDBC may be associated with several CSF disorder-related neurological disorders in clinical practice. Therefore, the morphology of the MDBC and its influencing factors must be determined. In this study, T2-weighted imaging sagittal images of the cervical region were analyzed retrospectively in 1085 patients, and magnetic resonance imaging (MRI) typing of the MDBC was performed according to the imaging features of the MDBC in the posterior atlanto-occipital interspace (PAOiS) and posterior atlanto-axial interspace (PAAiS). The effects of age and age-related degenerative changes in the cervical spine on MRI staging of the MDBC were also determined. The results revealed four MRI types of the MDBC: type A (no MDBC hyposignal shadow connected to the dura mater in either the PAOiS or PAAiS), type B (MDBC hyposignal shadow connected to the dura mater in the PAOiS only), type C (MDBC hyposignal shadow connected to the dura mater in the PAAiS only), and type D (MDBC hyposignal shadow connected to the dura mater in both the PAOiS and PAAiS). The influencing factors for the MDBC typing were age (group), degree of intervertebral space stenosis, dorsal osteophytosis, and degenerative changes in the cervical spine (P < 0.05). With increasing age (10-year interval), the incidence of type B MDBC markedly decreased, whereas that of type A MDBC increased considerably. With the deepening of the degree of intervertebral space stenosis, the incidence of type C MDBC increased significantly, whereas that of type A MDBC decreased. In the presence of dorsal osteophytosis, the incidence of type C and D MDBCs significantly decreased, whereas that of type A increased. In the presence of protrusion of the intervertebral disc, the incidence of type B, C, and D MDBCs increased markedly, whereas that of type A MDBC decreased considerably, with cervical degenerative changes combined with spinal canal stenosis. Moreover, the incidence of both type C and D MDBCs increased, whereas that of type A MDBC decreased. Based on the MRI signal characteristics of the dural side of the MDBC, four types of the MDBC were identified. MDBC typing varies dynamically according to population distribution, depending on age and cervical degeneration (degree of intervertebral space stenosis, vertebral dorsal osteophytosis formation, simple protrusion of intervertebral disc, and cervical degeneration changes combined with spinal canal stenosis, except for the degree of protrusion of the intervertebral disc and the degree of spinal canal stenosis); however, it is not influenced by sex.

How Dedicated Ribosomes Translate a Leaderless mRNA

In bacteriophage λ lysogens, the λcI repressor is encoded by the leaderless transcript (lmRNA) initiated at the λpRM promoter. Translation is enhanced in rpsB mutants deficient in ribosomal protein uS2. Although translation initiation of lmRNA is conserved in bacteria, archaea, and eukaryotes, structural insight of a lmRNA translation initiation complex is missing. Here, we use cryo-EM to solve the structures of the uS2-deficient 70S ribosome of host E. coli mutant rpsB11 and the wild-type 70S complex with λcI lmRNA and fMet-tRNAfMet. Importantly, the uS2-deficient 70S ribosome also lacks protein bS21. The anti-Shine-Dalgarno (aSD) region is structurally supported by bS21, so that the absence of the latter causes the aSD to divert from the normal mRNA exit pathway, easing the exit of lmRNA. A π-stacking interaction between the monitor base A1493 and A(+4) of lmRNA potentially acts as a recognition signal. Coulomb charge flow, along with peristalsis-like dynamics within the mRNA entrance channel due to the increased 30S head rotation caused by the absence of uS2, are likely to facilitate the propagation of lmRNA through the ribosome. These findings lay the groundwork for future research on the mechanism of translation and the co-evolution of lmRNA and mRNA that includes the emergence of a defined ribosome-binding site of the transcript.

Three-dimensional characteristics of nystagmus induced by low frequency in semicircular canals of healthy young people.

The study aimed to analyze the three-dimensional characteristics of nystagmus induced by different semicircular canal combinations in healthy young people, and to determine the reference range of nystagmus slow phase velocity (SPV) and its asymmetry. Fifty-two healthy volunteers (26 males and 26 females, aged 17-42 years, average 23.52 ± 6.59), were recruited to perform the manual triaxial rotation testing with a 3D-Videonystagmography (3D-VNG) device (VertiGoggles (ZT-VNG-II), Shanghai ZEHNIT Medical Technology Co., Ltd., Shanghai, China) using a 0.3 Hz prompt beat and a 90° amplitude, respectively. The induced nystagmus around the Z-, X-, and Y-axes were recorded in the yaw, pitch, and roll planes. The directions and slow phase velocities of the horizontal, vertical, and torsional components of the induced nystagmus under different semicircular canal combinations (the left lateral and right lateral semicircular canal combination, bilateral anterior semicircular canals, bilateral posterior semicircular canals combination, and the anterior and posterior semicircular canals combination of each ear), as well as their asymmetry, were taken as the observation indexes to analyze the characteristics of the nystagmus vectors of different combinations. Fifty-two healthy volunteers had no spontaneous nystagmus. The characteristic nystagmus was induced by the same head movement direction in all three axial rotation tests. The SPVs of the left and right nystagmus were 44.45 ± 15.75°/s and 43.79 ± 5.42°/s, respectively, when the subjects' heads were turned left or right around the Z-axis (yaw). The SPVs of vertically upward and downward nystagmus were 31.67 ± 9.46°/s and 30.01 ± 9.20°/s, respectively, when the subjects' heads were pitched around the X-axis (pitch). The SPVs of torsional nystagmus, with the upper poles of the eyes twisting slowly to the right and left ears (from the participant's perspective), were 28.99 ± 9.20°/s and 28.35 ± 8.17°/s, respectively, when the subjects' heads were turned left or right around the Y-axis (roll). There was no significant difference in the SPVs of nystagmus induced by the same rotation axis in two opposite directions (p > 0.05). The reference ranges for the slow phase velocities (SPVs) of nystagmus induced by the triaxial rotation testing were as follows: For the Z-axis (yaw), the SPVs were 13.58-75.32°/s for leftward head rotation and 13.56-74.02°/s for rightward head rotation. For the X-axis (pitch), the SPVs were 13.13-50.21°/s for upward head nystagmus and 11.98-48.04°/s for downward head nystagmus. For the Y-axis (roll), the SPVs were 10.97-47.02°/s for the left-sided head rotation and 12.34-44.35°/s for the right-sided head rotation. This study clarified the three-dimensional characteristics of nystagmus induced by different semicircular canal combinations in healthy young people. It also established a preliminary reference range of SPVs and SPV asymmetry of nystagmus induced by the vertical semicircular canal. It can further provide a basis for the mechanism of semicircular canal-induced nystagmus and the traceability of nystagmus in patients with otogenic vertigo. It is shown that the portable 3D-VNG eye mask can be used for the manual triaxial rotation testing to achieve the evaluation of the low-frequency angular vestibulo-ocular reflex (aVOR) function of the vertical semicircular canal, which is convenient, efficient, and practical.

Langevin dynamics simulations for the critical adsorption of end-grafted active polymers.

The critical adsorption of end-grafted active polymer chains on an attractive surface is studied using Langevin dynamics simulations. The active polymers are composed of an active Langevin particle located at the head and a sequential passive chain. Results show that the active force exerted by the active head pulls the active polymer away from the surface. Consequently, the adsorption of the active polymer is hindered, and the critical surface attraction strength, , increases proportionally to the square of the active force, Fa2. The increase in depends on the rotation behavior of the active head. Specifically, for the restricted rotating active polymer (RRAP) chain with a longer rotational persistence time as the rotation of the active head is restricted, increases significantly with Fa. On the other hand, for the freely rotating active polymer (FRAP) chain with a shorter rotational persistence time as the rotation of the active head is free, shows a weak dependence on Fa. The results show that the active force has a significantly stronger pulling effect on the RRAP chain than on the FRAP chain. Furthermore, knotted conformations are observed for the adsorbed RRAP chain at large Fa. These knots reduce the adsorption of monomers near the grafted end. In contrast, no knotted conformations are observed for the FRAP chains due to the comparatively weaker pulling effect of the active force.

Incongruent active head rotations increase visual motion detection thresholds.

Attributing a visual motion signal to its correct source-be that external object motion, self-motion, or some combination of both-seems effortless, and yet often involves disentangling a complex web of motion signals. Existing literature focuses on either translational motion (heading) or eye movements, leaving much to be learnt about the influence of a wider range of self-motions, such as active head rotations, on visual motion perception. This study investigated how active head rotations affect visual motion detection thresholds, comparing conditions where visual motion and head-turn direction were either congruent or incongruent. Participants judged the direction of a visual motion stimulus while rotating their head or remaining stationary, using a fixation-locked Virtual Reality display with integrated head-movement recordings. Thresholds to perceive visual motion were higher in both active-head rotation conditions compared to stationary, though no differences were found between congruent or incongruent conditions. Participants also showed a significant bias to report seeing visual motion travelling in the same direction as the head rotation. Together, these results demonstrate active head rotations increase visual motion perceptual thresholds, particularly in cases of incongruent visual and active vestibular stimulation.

Multiple Monitors or Single Canvas? Evaluating Window Management and Layout Strategies on Virtual Displays.

Virtual displays enabled through head-worn augmented reality have unique characteristics that can yield extensive amounts of screen space. Existing research has shown that increasing the space on a computer screen can enhance usability. Since virtual displays offer the unique ability to present content without rigid physical space constraints, they provide various new design possibilities. Therefore, we must understand the trade-offs of layout choices when structuring that space. We propose a single Canvas approach that eliminates boundaries from traditional multi-monitor approaches and instead places windows in one large, unified space. Our user study compared this approach against a multi-monitor setup, and we considered both purely virtual systems and hybrid systems that included a physical monitor. We looked into usability factors such as performance, accuracy, and overall window management. Results show that Canvas displays can cause users to compact window layouts more than multiple monitors with snapping behavior, even though such optimizations may not lead to longer window management times. We did not find conclusive evidence of either setup providing a better user experience. Multi-Monitor displays offer quick window management with snapping and a structured layout through subdivisions. However, Canvas displays allow for more control in placement and size, lowering the amount of space used and, thus, head rotation. Multi-Monitor benefits were more prominent in the hybrid configuration, while the Canvas display was more beneficial in the purely virtual configuration.

Investigation of vestibular function in patients with vestibular neuritis

To optimize the diagnostic algorithm for vestibular neuritis based on an assessment of the sensitivity of clinical methods for studying vestibular function in the recovery period of the disease. A comprehensive assessment of the sensitivity of clinical methods for the study of vestibular function in the acute (up to 14 days: at the time of initial treatment, on the 7th and 14th day) and subacute (up to 3 months: on the 28th and 90th day) periods of the disease in 52 patients with upper vestibular neuritis was carried out. The timing of the processes of restoration of vestibular function after a transferred vestibular neuritis is individual: after 14 days, restoration of vestibular function was recorded in 52% (n=27) patients, after 1 month - in 62% (n=32), after 3 months - in 71% (n=37) patients with upper vestibular neuritis. Statocoordination, statokinetic, oculomotor tests under visual control have the highest sensitivity in the acute period of vestibular neuritis, within up to 7 days from the onset of symptoms. In the subacute period of vestibular neuritis, the study of spontaneous nystagmus and nystagmus in the head shaking test retains high sensitivity only when using special tools (Frenzel goggles or videonystagmography). A decrease in the sensitivity of the head rotation test and the dynamic visual acuity test in the subacute period of vestibular neuritis is associated with the processes of central compensation and the formation of a latent saccade. The sensitivity of clinical tests in patients with vestibular neuritis depends on the timing of the examination.

The Influence of Body Posture on the Mirror Neuron System

Though the mirror neuron system (MNS) is studied in the scientific community, the influence of the body posture on the functioning of the MNS, as well as on the excitatory and inhibitory system of the brain, has not been revealed yet. In our study, we investigated the functioning of the MNS in case of head rotation. Participants underwent a session of the mirror task, while they were observing movements of the little finger and the index finger of a static hand in three head positions (left, straight and right), combined with transcranial magnetic stimulation (TMS) that was applied at various time intervals. Results showed significant interactions between the movement type and the targeted muscle (F[1,113–16,688] = 9.47, MSE = 56296.14, p = .006, partial η2 = .39). This indicates a robust increase in the activation of the First Dorsal Interosseous (FDI) muscle during the index finger movement (p = .01) and the neutral movement (p .001) observation compared to the little finger movement. Conversely, a significant inhibition of the Abductor Digiti Minimi (ADM) muscle activity was observed during the index finger movement compared to neutral (p = .026). A reversed effect emerged during the little finger movement observation, with higher activation for the ADM muscle and inhibition of the FDI muscle (p = .037). These findings suggest an intricate interplay between MNS activation and muscle activation, indicating an increase in muscle activity corresponding to the observed finger movement and simultaneous inhibition of the muscle not involved in the observed movement.

Toward Robust and Unconstrained Full Range of Rotation Head Pose Estimation.

Estimating the head pose of a person is a crucial problem for numerous applications that is yet mainly addressed as a subtask of frontal pose prediction. We present a novel method for unconstrained end-to-end head pose estimation to tackle the challenging task of full range of orientation head pose prediction. We address the issue of ambiguous rotation labels by introducing the rotation matrix formalism for our ground truth data and propose a continuous 6D rotation matrix representation for efficient and robust direct regression. This allows to efficiently learn full rotation appearance and to overcome the limitations of the current state-of-the-art. Together with new accumulated training data that provides full head pose rotation data and a geodesic loss approach for stable learning, we design an advanced model that is able to predict an extended range of head orientations. An extensive evaluation on public datasets demonstrates that our method significantly outperforms other state-of-the-art methods in an efficient and robust manner, while its advanced prediction range allows the expansion of the application area. We open-source our training and testing code along with our trained models: https://github.com/thohemp/6DRepNet360.

Эссенциальная младенческая эзотропия

Relevance. Essential infantile esotropia (EIE) is the most common type of childhood strabismus. The incidence of EIE varies on average from 0.1 to 1.0% in the general population of children, which is significant for timely diagnosis and provision of appropriate assistance to this category of patients. The exact etiology of infantile essential esotropia remains unknown, but historically a number of conflicting theories have been proposed. Purpose. To summarize the accumulated experience in the field of studying EIE to determine the optimal path to achieving the main goal of treatment – achieving orthoposition with the subsequent formation of binocular vision in this category of patients. Material and methods. To complete the review, a search of literature sources was carried out in the PubMed and Scopus abstract databases for the period up to 2022 inclusive. A total of 32 articles relevant to the review topic were selected and analyzed. Results. Having analyzed the literature data, we can conclude that today there is no unified classification of infant essential esotropia, but a certain symptom complex of clinical manifestations has been identified that are pathognomonic for this type of strabismus. Usually, EIE manifests in the first 6 months of life, appears a large horizontal esodeviation, may be accompanied by latent nystagmus, compensatory head rotation, and cross-fixation syndrome. This type of strabismus occurs in infants with normal age-related refraction and normal neurological status. The clinical approach to tactics and methods of treatment of infantile esotropia varies widely in the strabismus world. There are conflicting opinions regarding the following issues: the optimal timing for the operation, the most effective type of operation, and what determines the favorable outcome of the treatment of essential congenital esotropia. Conclusion. Many aspects of EIE remain controversial and poorly defined. To optimally realize the main goal of EIE treatment – achieving orthoposition with the subsequent formation of binocular vision – is a feasible task, which will soon find a solution. Key words: essential infantile esotropia, latent nystagmus, cross fixation syndrome, binocular vision

Localization of brain signals by alternating projection

A popular approach for modeling brain activity in MEG and EEG is based on a small set of current dipoles, where each dipole represents the combined activation of a local area of the brain. Here, we address the problem of multiple dipole localization with a novel solution called Alternating Projection (AP). The AP solution is based on minimizing the least-squares (LS) criterion by transforming the multi-dimensional optimization required for direct LS solution, to a sequential and iterative solution in which one source at a time is localized, while keeping the other sources fixed. Results from simulated, phantom, and human MEG data demonstrated the high accuracy of the AP method, with superior localization results than popular scanning methods from the multiple-signal classification (MUSIC) and beamformer families. In addition, the AP method was more robust to forward model errors resulting from head rotations and translations, as well as different cortex tessellation grids for the forward and inverse solutions, with consistently higher localization accuracy in low SNR and highly correlated sources.

Internal manual rotation in intrapartal arrest of fetal head engagement

ObjectiveThe success of internal manual or digital rotation of the head in mechanical dystocia due to malpresentation, malposition or malrotation is presented in this paper on our own clinical material with reference of today's research and clinical recommendations. Study designThrough a retrospective bicentric clinical study, we investigated the success of internal head rotation in two University Clinics for gynecology and obstetrics from year 2017 to 2023. In 152 singleton term (37–42 weeks) in cases of persistens intrapartum arrest of the fetal head. After palpatory and ultrasonographically verified arrest of fetal head engagement, a therapeutic manual (Liepmann) or digital rotation was performed. ResultsIn 152 cases, manual rotation was performed in 108 (71.05 %) and digital rotation in 44 (28.94 %) cases in 73 (48.02 %) primiparous and 79 (51.97 %) multiparous. Intrapartum identification by digital palpation was done in all cases, and the following are: persistent occipital posterior position in 68 (44.73%), persistent deep transverse head presentation in 12 (7.89%), persistent high (longitudinal) occipital presentation in 64 (42.10 %) and persistent anterior asynclitism in 8 (5.26 %) cases. Episiotomy was used in 36 (23.68%) cases. Vacuum extraction was completed in 14 (9.21 %) deliveries, and cesarean section due to unsuccessful internal rotation in 15 (9.8 %) cases (%) without other indication. We did not record any intrapartum complications or cardiotocographic abnormalities. Cervical lacerations were treated with sutures in 4 cases (2.63 %). Successful correction of internal rotation procedure with spontaneous vaginal delivery was found in 80.92 % of cases. If we exclude delivery assisted by vacuum extraction whose indications were fetal hypoxia or dystocia after successful internal head rotation procedure, then the success rate of this method was 90.13 %. ConclusionInternal head rotation is a simple, safe and successful obstetric manual intervention that directly increases the rate of vaginal deliveries after correction of the birth mechanism anomaly and directly reduces the percentage of cesarean section. Manual or digital head rotation is an established midwifery/obstetric skill in several centers which, based on numerous clinical researches and experience, should become protocolized and included in the guidelines of professional associations.

A Wearable Wireless Magnetic Eye-Tracker, In-Vitro and In-Vivo Tests.

A wireless, wearable magnetic eye tracker is described and characterized. The proposed instrumentation enables simultaneous evaluation of eye and head angular displacements. Such a system can be used to determine the absolute gaze direction as well as to analyze spontaneous eye re-orientation in response to stimuli consisting in head rotations. The latter feature has implications to analyze the vestibulo-ocular reflex and constitutes an interesting opportunity to develop medical (oto-neurological) diagnostics. Details of data analysis are reported together with some results obtained in-vivo or with simple mechanical simulators that enable measurements under controlled conditions.