Effect Of Occlusion Research Articles

Meta-earplugs: Innovative concepts for alleviating the occlusion effect

Passive earplugs are commonly used to reduce workers' exposure to excessively high noise levels. Yet, they are associated with various discomforts of diverse origins (e.g., acoustic, physical, functional, or psychological). The occlusion effect, characterized by an increased perception of physiological sounds transmitted through bone conduction to the cochlea, presents a challenge, leading to acoustic discomfort, especially at low frequencies (0.1 to 1 kHz) and for shallow or moderate insertion depths of the earplug. Building upon acoustic meta-material principles, this study presents “meta-earplug” concepts designed to alleviate the occlusion effect. The approach focuses on reducing the input impedance of the earplug medial surface either to the characteristic impedance of air, using broadband perfect absorption, or to the acoustic impedance of the open ear canal, resulting in a zero objective occlusion effect. For these purposes, the proposed meta-earplug concepts are made of Helmholtz resonators arranged in parallel or series. Transfer matrix models are used in an optimization process to refine the geometry of the meta-earplugs. Although meta-earplug concepts involving multiple Helmholtz resonators have been preliminarily assessed using an artificial ear, a meta-earplug featuring a single resonator has undergone testing with human participants. The evaluation encompasses both objective measurements and subjective assessments.

Designing an acoustical test fixture to evaluate the objective occlusion effect

Earplugs are commonly used to prevent noise-induced hearing loss. However, their effectiveness is often hindered by the discomfort they cause, impacting consistent and correct use. An important acoustical discomfort, known as the occlusion effect, arises from an increased perception of bone-conducted physiological sounds (such as one's own voice, breathing, and chewing) when the ear canal is occluded. To objectively assess this discomfort, the study proposes the use of an acoustical test fixture (ATF) that avoids direct measurements on human participants. The ATF employs an anatomically realistic truncated outer ear, incorporating soft tissues, cartilage, and bone components to replicate the outer ear's bone conduction path, crucial for occlusion effect assessments. The study demonstrates that the proposed ATF can replicate key effects observed in objective ccclusion effect (OE) measurements on human participants, including significant OE at low frequencies diminishing with increasing frequency, reduction of OE with greater insertion depths, and distinctions among various earplug types—especially noticeable at deeper insertions. Furthermore, a computationally efficient finite element method-based virtual tester for the ATF is developed and validated.

Electroacupuncture regulates histone acetylation of Bcl-2 and Caspase-3 genes to improve ischemic stroke injury

BackgroundImbalances between Bcl-2 and caspase-3 are significant evidence of apoptosis, which is considered an influential factor in rapidly occurring neuronal cell death and the decline of neurological function after stroke. Studies have shown that acupuncture can reduce poststroke brain cell damage via either an increase in Bcl-2 or a reduction in caspase-3 exposure. The current study aimed to investigate whether acupuncture could modulate Bcl-2 and caspase-3 expression through histone acetylation modifications, which could potentially serve as a neuroprotective mechanism. MethodsThis study used TTC staining, Nissl staining, Clark neurological system score, and Evans Blue (EB) extravasation to evaluate neurological damage following stroke. The expression of Bcl-2/caspase-3 mRNA was detected by real-time fluorescence quantification of PCR (real-time PCR), whereas the protein expression levels of Bcl-2, Bax, caspase-3, and cleaved caspase-3 were assessed using western blotting. TUNEL staining of the ischemic cortical neurons determined apoptosis in the ischemic cortex. Histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities, along with the protein performance of AceH3, H3K9ace, and H3K27ace, were detected to evaluate the degree of histone acetylation. The acetylation enrichment levels of H3K9 and K3K27 in the Bcl-2/caspase-3 gene were assessed using Chromatin Immunoprecipitation (ChIP) assay. ResultsOur data demonstrated that electroacupuncture (EA) exerts a significant neuroprotective effect in middle cerebral artery occlusion (MCAO) rats, as evidenced by a reduction in infarct volume, neuronal damage, Blood-Brain Barrier (BBB) disruption, and decreased apoptosis of ischemic cortical neurons. EA treatment can promote the mRNA and protein expression of the Bcl-2 gene in the ischemic brain while reducing the mRNA and protein expression levels of caspase-3 and effectively decreasing the protein expression levels of Bax and cleaved caspase-3. More importantly, EA treatment enhanced the level of histone acetylation, including Ace-H3, H3K9ace, and H3K27ace, significantly enhanced the occupancy of H3K9ace/H3K27ace at the Bcl-2 promoter, and reduced the enrichment of H3K9ace and H3K27ace at the caspase-3 promoter. However, the Histone Acetyltransferase inhibitor (HATi) treatment reversed these effects. ConclusionsOur data demonstrated that EA mediated the expression levels of Bcl-2 and caspase-3 in MCAO rats by regulating the occupancy of acetylated H3K9/H3K27 at the promoters of these two genes, thus exerting a cerebral protective effect in ischemic reperfusion (I/R) injury.

The role of β-adrenergic receptors in the regulation of cardiac tolerance to ischemia/reperfusion. Why do β-adrenergic receptor agonists and antagonists protect the heart?

Catecholamines and β-adrenergic receptors (β-ARs) play an important role in the regulation of cardiac tolerance to the impact of ischemia and reperfusion. This systematic review analyzed the molecular mechanisms of the cardioprotective activity of β-AR ligands. We performed an electronic search of topical articles using PubMed databases from 1966 to 2023. We cited original in vitro and in vivo studies and review articles that documented the cardioprotective properties of β-AR agonists and antagonists. The infarct-reducing effect of β-AR antagonists did not depend on a decrease in the heart rate. The target for β-blockers is not only cardiomyocytes but also neutrophils. β1-blockers (metoprolol, propranolol, timolol) and the selective β2-AR agonist arformoterol have an infarct-reducing effect in coronary artery occlusion (CAO) in animals. Antagonists of β1- and β2-АR (metoprolol, propranolol, nadolol, carvedilol, bisoprolol, esmolol) are able to prevent reperfusion cardiac injury. All β-AR ligands that reduced infarct size are the selective or nonselective β1-blockers. It was hypothesized that β1-AR blocking promotes an increase in cardiac tolerance to I/R. The activation of β1-AR, β2-AR, and β3-AR can increase cardiac tolerance to I/R. The cardioprotective effect of β-AR agonists is mediated via the activation of kinases and reactive oxygen species production. It is unclear why β-blockers with the similar receptor selectivity have the infarct-sparing effect while other β-blockers with the same selectivity do not affect infarct size. What is the molecular mechanism of the infarct-reducing effect of β-blockers in reperfusion? Why did in early studies β-blockers decrease the mortality rate in patients with acute myocardial infarction (AMI) and without reperfusion and in more recent studies β-blockers had no effect on the mortality rate in patients with AMI and reperfusion? The creation of more effective β-AR ligands depends on the answers to these questions.

Association of transcatheter left atrial appendage occlusion with acute changes in left atrial pressure: An invasive hemodynamic study

BackgroundThe hemodynamic effects of transcatheter left atrial appendage occlusion (LAAO) remain unclear. ObjectiveWe sought to assess the effect of LAAO on invasive hemodynamics and their correlation with clinical outcomes. MethodsWe recorded mean left atrial pressure (mLAP) before and after device deployment. We assessed the prevalence and predictors of mLAP increase after deployment, the association between significant mLAP increase after deployment and 45-day peridevice leak (PDL), and the association between mLAP increase and heart failure (HF) hospitalization. A significant mLAP increase was defined as one equal to or greater than the mean percentage increase in mLAP after deployment (≥28%). ResultsWe included 302 patients (36.4% female; mean age, 75.8 ± 9.5 years). After deployment, mLAP increased in 48% of patients, 38% of whom experienced significant mLAP increase. Independent predictors of mLAP increase were baseline mLAP ≤14 mm Hg, nonparoxysmal atrial fibrillation, and age per 5 years (odds ratios: 3.66 [95% CI, 2.21–6.05], 1.81 [95% CI, 1.08–3.02], and 0.85 [95% CI, 0.73–0.99], respectively). Significant mLAP increase was an independent predictor of 45-day PDL (odds ratio, 2.55; 95% CI, 1.04–6.26). There was no association between mLAP increase and HF hospitalization. ConclusionAfter deployment, mLAP acutely rises in 48% of patients, although this is not associated with increased HF hospitalizations. PDL is more likely to develop at 45 days in patients with significant increase in mLAP after deployment, although most leaks were small (<5 mm). These findings suggest that mLAP increase after deployment is not associated with major safety concerns. Additional studies are warranted to explore the long-term hemodynamic effects of LAAO.

Effect of resuscitative endovascular balloon occlusion of the aorta in nontraumatic out-of-hospital cardiac arrest: a multinational, multicenter, randomized, controlled trial

BackgroundOut-of-hospital cardiac arrest (OHCA) is a significant public health issue worldwide and is associated with low survival rates and poor neurological outcomes. The generation of optimal coronary perfusion pressure (CPP) via high-quality chest compressions is a key factor in enhancing survival rates. However, it is often challenging to provide adequate CPP in real-world cardiopulmonary resuscitation (CPR) scenarios. Based on animal studies and human trials on improving CPP in patients with nontraumatic OHCA, resuscitative endovascular balloon occlusion of the aorta (REBOA) is a promising technique in these cases. This study aims to investigate the benefits of REBOA adjunct to CPR compared with conventional CPR for the clinical management of nontraumatic OHCA.MethodsThis is a parallel-group, randomized, controlled, multinational trial that will be conducted at two urban academic tertiary hospitals in Korea and Taiwan. Patients aged 20–80 years presenting with witnessed OHCA will be enrolled in this study. Eligible participants must fulfill the inclusion criteria, and written informed consent should be collected from their legal representatives. Patients will be randomly assigned to the intervention (REBOA-CPR) or control (conventional CPR) group. The intervention group will receive REBOA and standard advanced cardiovascular life support (ACLS). Meanwhile, the control group will receive ACLS based on the 2020 American Heart Association guidelines. The primary outcome is the return of spontaneous circulation (ROSC). The secondary outcomes include sustained ROSC, survival to admission, survival to discharge, neurological outcome, and hemodynamic changes.DiscussionOur upcoming trial can provide essential evidence regarding the efficacy of REBOA, a mechanical method for enhancing CPP, in OHCA resuscitation. Our study aims to determine whether REBOA can improve treatment strategies for patients with nontraumatic OHCA based on clinical outcomes, thereby potentially providing valuable insights and guiding further advancements in this critical public health area.Trial registrationClinicalTrials.gov NCT06031623. Registered on September 9, 2023

Changes in Cardiac Electrical Biomarker in Response to Coronary Arterial Occlusion: An Experimental Observation.

Cardiac electrical biomarker (CEB), an indicator of ischaemia-induced change in myocyte polarity, has been proposed for diagnosis of acute coronary syndrome. However, effect of coronary occlusion on CEB has not been demonstrated. CEB was acquired before (CEB0), during maximal adenosine hyperaemia (CEBhyp), balloon inflations (CEBmax) and 1 (CEB1h), 2 (CEB2h) and 3 (CEB3h) h after percutaneous coronary intervention along with pre- and post-procedural troponin-I. CEB of subjects with non-cardiac chest pain without risk factors was used as controls (CEBc). "Late recovery" (LR) of CEB was defined as CEB3h > median-CEB0. CEB was recorded in 75 patients undergoing stenting (group 1) including 8 with FFR < 0.8 (group 1a), 25 with FFR ≥ 0.8 (group 2) and 49 controls. In group 1, CEB0 (median, IQR) was higher than CEBc (48.0; 29.5-88.3 vs 30.0; 17.0-44.0; p < 0.001). CEBmax (185; 105.0-331.0) was higher than CEB0 (p < 0.0001). CEB1h (78.0; 31.5-143.8; p < 0.0001) and CEB2h (63.0; 31.5-114.3; p = 0.039) were higher than CEB0 while CEB3h (54.0; 24.3-94.8, p = 0.152) was similar. LR occurred in 50.7% patients. CEBmax predicted LR (OR 1.01, 95% CI 1.00-1.01, p < 0.001) (AUC 0.759, p < 0.001). CEB0 in group 1a and group 2 were similar (p = 0.524). CEBhyp was higher than CEB0 in group 1a (126.0, 109.5-266.0 vs 47.5, 20.5-73.5; p = 0.016) and group 2 (44.0, 27.8-104.8 vs 39.0, 24.0-90.3; p = 0.014). CEBhyp was higher in group 1a than 2 (p = 0.039). CEBhyp (AUC 0.75, p = 0.017) accurately predicted FFR < 0.8. Coronary arterial occlusion increases CEB that retains a "memory" of the ischaemic event. CEBhyp was higher only when FFR was ischaemic and accurately identified FFR < 0.8.

Enhancing Human Action Recognition with 3D Skeleton Data: A Comprehensive Study of Deep Learning and Data Augmentation

Human Action Recognition (HAR) is an important field that identifies human behavior through sensor data. Three-dimensional human skeleton data extracted from the Kinect depth sensor have emerged as a powerful alternative to mitigate the effects of lighting and occlusion of traditional 2D RGB or grayscale image-based HAR. Data augmentation is a key technique to enhance model generalization and robustness in deep learning while suppressing overfitting to training data. In this paper, we conduct a comprehensive study of various data augmentation techniques specific to skeletal data, which aim to improve the accuracy of deep learning models. These augmentation methods include spatial augmentation, which generates augmented samples from the original 3D skeleton sequence, and temporal augmentation, which is designed to capture subtle temporal changes in motion. The evaluation covers two publicly available datasets and a proprietary dataset and employs three neural network models. The results highlight the impact of temporal augmentation on model performance on the skeleton datasets, while exhibiting the nuanced impact of spatial augmentation. The findings underscore the importance of tailoring augmentation strategies to specific dataset characteristics and actions, providing novel perspectives for model selection in skeleton-based human action recognition tasks.

Cross-scale Vision Transformer for crowd localization

Crowd localization can provide the positions of individuals and the total number of people, which has great application value for security monitoring and public management, meanwhile it meets the challenges of lighting, occlusion and perspective effect. In recent times, Transformer has been applied in crowd localization to overcome these challenges. Yet such kind of methods only consider to integrate the multi-scale information once, which results in incomplete multi-scale information fusion. In this paper, we propose a novel Transformer network named Cross-scale Vision Transformer (CsViT) for crowd localization, which simultaneously fuses multi-scale information during both the encoder and decoder stages and meanwhile building the long-range context dependencies on the combined feature maps. To this end, we design the multi-scale encoder to fuse the feature maps of multiple scales at corresponding positions so as to obtain the combined feature maps, and meanwhile design the multi-scale decoder to integrate the tokens at multiple scales when modeling the long-range context dependencies. Furthermore, we propose Multi-scale SSIM (MsSSIM) loss to adaptively compute head regions and optimize the similarity at multiple scales. Specifically, we set the adaptive windows with different scales for each head and compute the loss values within these windows so as to enhance the accuracy of the predicted distance transform map. We perform comprehensive experiments on five public datasets, and the results obtained validate the effectiveness of our method.

Immediate and Delayed Effects of Punctal Plug Insertion on Tear Meniscus Height in Severe Aqueous-Deficient Dry Eye.

The aim of this study was to assess the immediate and delayed effects of tear punctal occlusion with punctal plugs on tear meniscus height (TMH) in severe aqueous-deficient dry eye (ADDE) disease. Consecutive patients with severe ADDE related to Sjögren syndrome or ocular graft-versus-host disease underwent inferior and superior occlusion with punctal plugs. TMH was measured using the LacryDiag ocular surface analyzer platform before, 10 minutes, and at least 1 month after punctal occlusion. The corneal fluorescein staining (CFS) score was graded with the Oxford scale (from 0 to 5). Ocular symptoms were graded with a visual analog scale (from 1 to 10). We included 24 eyes of 24 patients (mean age 61 ± 9 years; mean follow-up 7 ± 5 months). The mean TMH was 0.19 ± 0.06 mm at baseline and increased significantly to 0.41 ± 0.13 mm (P < 0.001) and 0.46 ± 0.17 mm (P < 0.001) at 10 minutes after punctal plug insertion and at the end of follow-up, respectively. The median CFS score decreased from 3 ± 1 before plug insertion to 1 ± 2 at the end of follow-up (P < 0.001). Many patients (67%; n = 16) reported subjective improvement of symptoms. TMH was negatively correlated with the CFS score and visual analog scale score assessing symptoms. Upper and lower punctal occlusion increased TMH in patients with severe ADDE as soon as 10 minutes after plug insertion. TMH remained stable over time, which led to the relief of symptoms and reduced corneal staining.

Severe Bacterial Balanitis in Circumcised Adult Males

Balanitis is the inflammation of the glans penis while balanoposthitis involves both the glans penis and prepuce and occurs only in uncircumcised males. Balanitis is more common in uncircumcised males due to the occlusive effect of the foreskin, which facilitates smegma retention and bacterial and fungal overgrowth. Therefore, balanitis is rare after circumcision and severe balanitis is even rarer. In patients with recurrent balanoposthitis, circumcision is indicated, and the presence of diabetes should be ruled out. Diabetes mellitus is a frequent predisposing factor for Candida balanoposthitis and has been associated with male genital lichen sclerosus, which in progressive stages leads to phimosis. Circumcision is also indicated in the treatment of lichen sclerosus associated with phimosis. Candida albicans stands as the primary culprit in cases of acute infectious balanoposthitis, with aerobic bacteria constituting the second most common etiological factor. Among these bacteria, streptococci particularly groups B and D and staphylococci, notably S. aureus, are prevalent. Mixed infections may also occur. The typical clinical manifestations involve erythema and oedema accompanied by itching and/or pain. In instances of painful, erosive streptococcal balanoposthitis, severe balanopreputial oedema with purulent exudate can be observed. Staphylococcus haemolyticus, a prominent member of the coagulase-negative staphylococci of the skin microbiota, causes infections in the male urogenital tract, such as urinary tract infections, chronic prostatitis and epididymo-orchitis. However, it had not been associated with balanitis. Enterococcus faecalis is part of the normal gastrointestinal microflora and is also a frequent cause of urinary tract infections and of chronic prostatitis. Enterococcus has been associated with mild balanoposthitis in adults and E. faecalis has been described to cause balanoposthitis in young children, but its association with severe balanitis .....

Oxyberberine protects middle cerebral artery occlusion triggered cerebral injury through TLR4/NLRP3 pathway in rats

Cerebral ischemia is a life-threatening health concern that leads to severe neurological complications and fatalities worldwide. Although timely intervention with clot-removing agents curtails serious post-stroke neurological dysfunctions, no effective neuroprotective intervention is available for addressing post-recanalization neuroinflammation. Herein, for the first time we studied the effect of oxyberberine (OBB), a derivative of berberine, on transient middle cerebral artery occlusion (MCAO)-generated neurological consequences in Sprague-Dawley rats. The MCAO-operated rats exhibited significant somatosensory and sensorimotor dysfunctions in adhesive removal, foot fault, paw whisker, and rotarod assays at 1 and 3 days post-surgery. These MCAO-generated neurological deficits were prevented in OBB-treated (50 and 100 mg/kg) rats, and also coincided with a smaller infarct area (in 2,3,5-triphenyl tetrazolium chloride staining) and decreased neuronal death (in cresyl violet staining) in the ipsilateral hemisphere of these animals. The immunostaining of neuronal nuclear protein (NeuN) and glial-fibrillary acidic protein (GFAP) also echoes the neuroprotective nature of OBB. The increased expression of neuroinflammatory and blood-brain barrier tight junction proteins like toll-like receptor 4 (TLR4), TRAF-6, nuclear factor kappa B (NF-κB), pNF-κB, nNOS, ASC, and IKBα in the ipsilateral part of MCAO-operated rats were restored to normal following OBB treatment. We also observed the decline in plasma levels/mRNA transcription of TNF-α, IL-1β, NLRP3, IL-6, and matrix metalloproteinase-9 and increased expression of occludin and claudin in OBB-treated rats. These outcomes imply that OBB may prevent the MCAO-induced neurological consequences and neuroinflammation by interfering with TLR4 and NLRP3 signaling in rats.

Evaluation of C/N0 raw observation positioning by smartphone based on indoor asynchronous pseudolite

With the rapid development of the economy and information services, there is an increasing demand for indoor positioning. However, Global Navigation Satellite System (GNSS) signals face difficulties in penetrating buildings, making indoor positioning challenging. As a complementary solution to outdoor GNSS signals, pseudolites have shown promising results in various scenarios, and have become one of the research hotspots in the field of indoor positioning. Previous studies on indoor positioning with pseudolites have focused on issues such as initial position determination and carrier phase ambiguity resolution. However, most of these studies have remained in the research stage due to data post-processing and complex calculations. To overcome the limitations associated with the aforementioned factors, this paper proposes a real-time indoor positioning method that utilizes only a smartphone equipped with a built-in GNSS chip. By effectively obtaining pseudolite signal information, the smartphone establishes a simple model based on the distance and received power between the pseudolite and the smartphone. Kalman filtering is employed to mitigate the effects of multipath and occlusion. This simple and low-complexity model enables fast estimation of the user's distance from the pseudolite, thereby facilitating indoor positioning services. In this paper, the effectiveness and low complexity of the method are verified through data collection and experiments in the actual scene of the underground garage. The valuation results show that the root mean square error (RMSE) of its navigation and positioning is better than 3 m, which can meet the needs of daily life applications.

A Drop-By-Drop Self-Assembled All-Natural Hydrogel as a Desensitizer for Rapid and Enduring Management of Dentin Hypersensitivity.

Dentin hypersensitivity (DH) is a prevalent dental condition arising from the exposure of dentin tubules (DTs), leading to discomfort upon external stimuli. However, achieving swift and profound occlusion of these exposed DTs for immediate and enduring relief remains challenging due to the intricate dentin structure and oral environment. Herein, a pioneering and facile drop-by-drop strategy involving an in situ generated natural supramolecular hydrogel formed by self-assembling silk fibroin (SF) and tannic acid (TA) within the narrow DT space is proposed. When SF and TA aqueous solutions are applied successively to exposed dentin, they penetrate deeply within DTs and coassemble into compact gels, robustly adhering to DT walls. This yields a rapid and compact occlusion effect with an unprecedented depth exceeding 250µm, maintaining stable occlusion efficacy even under rigorous in vitro and in vivo erosion and friction conditions for no less than 21 days. Furthermore, the biocompatibility and effective occlusion properties are verified through cell studies in simulated oral settings and an in vivo rabbit model. This study, for the first time, demonstrates the translational potential of hydrogel-based desensitizers in treating DH with prompt action, superior occlusion depth and enduring treatment benefits, holding promise as clinical-friendly restorative solutions for delicate-structured biosystems.

Impact of the ear canal motion on the impedance boundary conditions in models of the occlusion effect.

The occlusion effect (OE) denotes the increased low-frequency perception of bone-conducted sounds when the ear canal (EC) is occluded. Circuit and finite element (FE) models are commonly used to investigate the OE and improve its prediction, often applying acoustic impedances at the EC entrance and tympanic membrane (TM). This study investigates the sound generation caused by the structural motion of the EC. In addition to the EC wall vibration, it accounts for the motions of the EC entrance and TM, resulting from nondeforming motion of the surrounding structures. A model extension including these motions with the impedances is proposed. Related mechanisms are illustrated based on a circuit model. Implications are discussed by using an EC motion extracted from a FE model of a human head. The results demonstrate that the motions of the EC entrance and TM, addressed by the proposed extension, affects the TM sound pressure and may lead to a reduction of the OE at lower frequencies compared to solely considering the EC wall vibration. Accordingly, this phenomenon potentially reconciles differences between experimental data and OE simulations at frequencies below about 250 Hz, highlighting the importance to discern between multiple contributing mechanisms to the TM sound pressure.

Individual tree segmentation in occluded complex forest stands through ellipsoid directional searching and point compensation

Terrestrial laser scanning (TLS) accurately captures tree structural information and provides prerequisites for tree-scale estimations of forest biophysical attributes. Quantifying tree-scale attributes from TLS point clouds requires segmentation, yet the occlusion effects severely affect the accuracy of automated individual tree segmentation. In this study, we proposed a novel method using ellipsoid directional searching and point compensation algorithms to alleviate occlusion effects. Firstly, region growing and point compensation algorithms are used to determine the location of tree roots. Secondly, the neighbor points are extracted within an ellipsoid neighborhood to mitigate occlusion effects compared with k-nearest neighbor (KNN). Thirdly, neighbor points are uniformly subsampled by the directional searching algorithm based on the Fibonacci principle in multiple spatial directions to reduce memory consumption. Finally, a graph describing connectivity between a point and its neighbors is constructed, and it is utilized to complete individual tree segmentation based on the shortest path algorithm. The proposed method was evaluated on a public TLS dataset comprising six forest plots with three complexity categories in Evo, Finland, and it reached the highest mean accuracy of 77.5%, higher than previous studies on tree detection. We also extracted and validated the tree structure attributes using manual segmentation reference values. The RMSE, RMSE%, bias, and bias% of tree height, crown base height, crown projection area, crown surface area, and crown volume were used to evaluate the segmentation accuracy, respectively. Overall, the proposed method avoids many inherent limitations of current methods and can accurately map canopy structures in occluded complex forest stands.

Performance and Reliability Evaluation of an Automated Bone-Conduction Audiometry Using Machine Learning.

To date, pure-tone audiometry remains the gold standard for clinical auditory testing. However, pure-tone audiometry is time-consuming and only provides a discrete estimate of hearing acuity. Here, we aim to address these two main drawbacks by developing a machine learning (ML)-based approach for fully automated bone-conduction (BC) audiometry tests with forehead vibrator placement. Study 1 examines the occlusion effects when the headphones are positioned on both ears during BC forehead testing. Study 2 describes the ML-based approach for BC audiometry, with automated contralateral masking rules, compensation for occlusion effects and forehead-mastoid corrections. Next, the performance of ML-audiometry is examined in comparison to manual and conventional BC audiometry with mastoid placement. Finally, Study 3 examines the test-retest reliability of ML-audiometry. Our results show no significant performance difference between automated ML-audiometry and manual conventional audiometry. High test-retest reliability is achieved with the automated ML-audiometry. Together, our findings demonstrate the performance and reliability of the automated ML-based BC audiometry for both normal-hearing and hearing-impaired adult listeners with mild to severe hearing losses.

Modeling of speech-dependent own voice transfer characteristics for hearables with an in-ear microphone

Many hearables contain an in-ear microphone, which may be used to capture the own voice of its user. However, due to the hearable occluding the ear canal, the in-ear microphone mostly records body-conducted speech, typically suffering from band-limitation effects and amplification at low frequencies. Since the occlusion effect is determined by the ratio between the air-conducted and body-conducted components of own voice, the own voice transfer characteristics between the outer face of the hearable and the in-ear microphone depend on the speech content and the individual talker. In this paper, we propose a speech-dependent model of the own voice transfer characteristics based on phoneme recognition, assuming a linear time-invariant relative transfer function for each phoneme. We consider both individual models and models averaged over several talkers. Experimental results based on recordings with a prototype hearable show that the proposed speech-dependent model enables to simulate in-ear signals more accurately than a speech-independent model in terms of technical measures, especially under utterance mismatch and talker mismatch. Additionally, simulation results show that talker-averaged models generalize better to different talkers than individual models.

Occlusal effects on text reading: an eye-tracker study.

Asymmetric electromyographic (EMG) activity during teeth clenching has been linked to cognitive impairment, as evaluated by the Spinnler-Tognoni matrices test, and to asymmetric pupil size (anisocoria). Anisocoria indicates an asymmetric Locus Coeruleus activity, leading to an asymmetric hemispheric excitability worsening cognitive performance. Bite splint wearing corrects EMG asymmetry, reduces anisocoria and improves cognitive performance. This study explores the possible effect of EMG asymmetry on oculomotor behavior during text reading. In subjects showing different degrees of EMG asymmetry during clenching, the number and duration of fixation periods during a reading task, performed under two different occlusal conditions were analyzed. The first lecture was executed with a dental impression (imprint) interposed between the dental arches (corrected condition) and the second one with the arches in direct contact (habitual condition), without clenching effort. The imprint reduced the EMG asymmetries during clenching. In both occlusal conditions, total reading time correlated with duration of fixations, but not with their number. An inverse relation was observed between the number of fixations and their duration across individuals. Fixation frequency and duration were positively and negatively correlated with the amplitude of EMG asymmetry, respectively. Differently, total reading time was not related to the EMG asymmetry. When switching from the corrected to the habitual condition, an increase in the number of fixations and a reduction in their duration was observed, while total reading time could be either increased or decreased. An increased fixation frequency was observed in most of the subjects, while a reduced duration only among individuals with shorter reading times in habitual condition. In the habitual condition, EMG asymmetry influences reading patterns (more saccades/shorter fixations, less saccades/longer fixations) in our sample. The changes in text reading behavior elicited by occlusal correction can be explained by assuming that occlusal disharmony negatively interferes with the reading task by increasing the number of saccades necessary for text scanning. This finding may also indicate an increased difficulty in processing of visual information. The potential involvement of trigeminal pathways in the relation between occlusal factors and oculomotor control is discussed.

Different effects of visual occlusion on interpersonal coordination of head and body movements during dyadic conversations.

In recent decades, interpersonal coordination and synchrony have been extensively examined in the field of psychology and cognitive science. Studies suggest that perceptual information enables interpersonal coordination and that perceptual noise may even enhance coordination. However, how these perceptual factors influence interpersonal coordination dynamics between head and body movements remains unclear. This study investigated the effect of visual information on the interpersonal coordination of head and body movements during dyadic conversations. The availability of visual information was manipulated by positioning a partition halfway between a pair of participants, and the conversations were recorded using a video camera. A video-based human pose estimation software (OpenPose) was used to quantify each interlocutor's head and body movements, which were submitted for cross-recurrence quantification analysis (CRQA), to assess the degree of coordination between the interlocutors. The results showed different effects between head- and body-movement coordination (i.e., a CRQA measure, maximum line length). The occlusion of visual information increased head-movement coordination, whereas it decreased body-movement coordination. The results suggest that a distinct mechanism may be present at the head- and body-movement coordination level and this study observed differing appearances of compensatory behaviors. Further studies should be conducted to investigate the complex relationships between interpersonal coordination dynamics and various kinds of communication constraints, such as long-term or short-term, and lower-order (perceptual-motor) or higher-order (cognitive-social) level constraints.