Variation In Position Research Articles

Changes in trunk postural control with different types of mounts with relevance for hippotherapy

BackgroundHippotherapy uses horseback riding movements for therapeutic purposes. In addition to the horse's movement, the choice of equipment and types of positions are also useful in the intervention. Trunk postural control demands can be manipulated through varying mounting materials and patient positioning on the horse. The quantification of trunk dynamic parameters under the interaction of the different types of riding material and the position variations act upon trunk postural control provides insight into how children with neurotypical development respond to a similar hippotherapy session. This study aimed to evaluate the postural control of the trunk of children with neurotypical development when the riding materials and positioning of the feet and hands support were modified during horse riding. MethodsFifteen children with neurotypical development, aged 6–12 years old, of both sexes, participated in a hippotherapy session. Postural control was measured by the mean amplitudes of oscillation of the lumbar (L5) and thoracic (T5) segments in the mediolateral, anteroposterior and rotational planes with a portable inertial measurement system, in situations using the saddle or blanket, hands resting on the straps or thigh and feet free or supported on the stirrup. ResultsDifferences were observed in lumbar and thoracic oscillation in the mediolateral direction. Values were significantly higher with the use of the blanket when the hands were on the handle and feet in the stirrups, compared to the use of the saddle. When using the blanket and feet positioned in the stirrups, statistical differences with higher values occurred with the hands on the handle compared to the thigh positioning. ConclusionThe use of the blanket equipment associated with the support of the hands on the handles and feet on the stirrups produces greater mediolateral oscillation in the subjects. DescriptorsBalance. Stability. Children. Hippotherapy. Kinematics.

A decentralized federated learning based interoperable and heterogeneity aware predictive optimization method for energy and comfort in smart homes environment

It is a known fact that a comfortable residential space or workspace is crucial to productivity and well-being. In smart home environments, sensors can be used to sense environment and occupant data and actuators can be controlled accordingly for maximizing thermal comfort. However, keeping in view the growing demand of energy and scarcity of energy generation sources, it is mandatory to optimize the energy usage complementary to optimize thermal comfort. In order for the developed method to be interoperable and heterogeneity aware across different edge device vendors and for ease of hardware connectivity in smart homes, a REST API based framework is developed. Sensors mounted with IoT devices collect data from its respective smart home environment and store the data in its local database. An edge server is used to control the connectivity among these IoT devices and to initiate the decentralized federated learning mechanism. Each IoT device train local deep learning models for predicting energy usage, indoor temperature, indoor humidity for maintaining a comfortable environment state using minimal energy. Models from each IoT devices are aggregated at each IoT device iteratively to make federated learning independent of central server. Global deep learning model is iteratively trained for each prediction requirement. Later, these models are used to predict indoor temperature, humidity and energy consumption for time stamp (t+1), keeping in view environmental and occupant related sensed data at time stamp (t). Optimization of energy consumption and thermal comfort is mathematically modeled and based on the predictions of DL models, environment is controlled by handling actuators using a particle swarm optimization (PSO) mechanism. Relevant constraints are incorporated in PSO for limiting the positional variations in particles for efficient learning. The method continually learns and adapts to changes in the surroundings, providing real-time monitoring and control of thermal comfort to the end users. To validate our approach, data is collected and experiments are conducted in a real-time smart home’s environment. The results are compared with those obtained without using the proposed predictive optimization mechanism. The study demonstrates the effectiveness of proposed predictive optimization mechanism in providing a comfortable and productive smart home or workspace environment utilizing 38% less energy as compared to competitor.

Thermo‐mechanical behavior of ball grid packages with different solder ball grid patterns investigated through moiré interferometry

AbstractPlastic ball‐grid array (PBGA) package assembly comprises various materials with different thermo‐mechanical properties, and the solder ball‐grid patterns can significantly influence the package deformation and solder ball stress. This study utilizes moiré interferometry to investigate the deformation behavior of wire bonded plastic ball‐grid array (WB‐PBGA) packages under varying temperatures. Real‐time moiré interferometry experiments were conducted to capture fringe patterns representing package deformation at different temperature stages. Experiments were conducted for three different wire bonded plastic ball‐grid array packages with distinct solder ball array configurations: full grid patterns (WB‐PBGA‐FG) and perimeter patterns with/without central connections (WB‐PBGA‐PC/P). The analysis revealed considerable variations in thermal strain distribution and positioning of the critical solder ball within the package assembly, depending on the solder ball‐grid pattern. Among these wire bonded plastic ball‐grid array packages, WB‐PBGA‐P/C exhibited the most substantial bending deformation, experiencing the highest effective strain, which directly impacts solder ball failure. These findings emphasize the importance of solder ball‐grid patterns in understanding the deformation behavior and reliability of WB‐PBGA packages under varying temperature conditions.

Quantifying bone loss and lateralization with standardized baseplate versus augmented baseplates

IntroductionReverse shoulder arthroplasty continues to be utilized for the treatment of cuff tear arthropathy, glenohumeral degenerative joint disease, and irreparable rotator cuff tears. With advancement in component designs, glenoid retroversion and inclination are now correctable with augmented baseplates. However, quantifying bone loss and lateralization compared to standard baseplates has not been studied. The purpose of the current study is to determine the volume of bone reamed and net lateralization with a standardized baseplate vs augmented baseplate when glenoid inclination was corrected to neutral. Materials and MethodsA series of 21 CT scans of patients presenting for shoulder arthroplasty were chosen based on a range of increasing native positive inclination. CT scans were uploaded into a segmentation software and processed. Four fellowship trained shoulder surgeons were then blinded from each other and virtually placed a neutral baseplate and an augmented baseplate for each specimen. Baseplate position was standardized. Additionally, baseplate backside seating of a minimum of 80% was also standardized and glenosphere (non-lateralized) size was selected to eliminate variation in baseplate contact and position. Glenoid inclination was corrected to a minimal of neutral in each specimen as well as glenoid retroversion corrected to < 10o. Net lateralization from the center of the glenoid to the most lateral aspect of the baseplate was calculated in millimeters. ResultsThe mean glenoid retroversion was 8.1o and superior inclination was 10.6o for all specimens. Across all specimens and surgeons, use of a 10-degree augment resulted in similar baseplate backside seating area (219.2 mm3 vs 226.2 mm3, p > 0.05). There was substantially lower volume of bone reamed in the augmented baseplate patients (619mm3 vs 1102mm3, p < 0.001). Larger standard deviation seen in the augmented baseplate columns are attributed to differences in surgeon preference for percent backside seating, which was standardized at a minimum of 80%. Use of a 10-degree full wedge augment resulted in 2.4 mm additional glenoid lateralization than a neutral baseplate on average across all included scapulae. ConclusionThe current study demonstrates approximately 50% less bone removal and 2.4 mm of true lateralization with a 10-degree augmented baseplate when compared to standard baseplates.

The ability of perfusion index and positional perfusion index variation to predict spinal anesthesia-induced hypotension in elderly patients: A prospective observational study

BackgroundSpinal anesthesia (SA) is a popular anesthetic technique for several surgeries; however, it is mostly associated with hypotension. The perfusion index (PI) can predict hypotension after spinal and general anesthesia. We aimed to evaluate the predictability of PI postural change, supine and sitting PI to post-SA hypotension in elderly patients. MethodsThis study was conducted on 68 elderly patients aged >65 years, scheduled for elective orthopedic surgical operations under SA in supine position. PI, arterial oxygen saturation, blood pressure, and heart rate were initially recorded at sitting and supine positions then 5, 10, and 20 min after subarachnoid drug injection (in supine position). ΔPI=PI supine−PI sitting. The relative change in PI (rPI) =ΔPI/PI sitting× 100. ResultsHypotension occurred in 33.82 % of patients. The Δ PI was 0.53±0.24, and the r PI was 14.18±6.41 %. Δ PI at cut-off >0.6 and r PI at cut-off > 14 %; could predict SA-induced hypotension with a sensitivity of 82.61 and 86.96 %, respectively, and specificity of 88.89 and 77.78 %, respectively. There was an insignificant difference between Δ PI and r PI and between r PI and baseline supine in predicting SA-induced severe hypotension. The prediction of SA-induced hypotension was higher with Δ PI than baseline sitting and baseline supine (P = 0.002 and 0.027) and between r PI and baseline sitting (P = 0.047). ConclusionsIn elderly patients, the Δ PI has a higher predictive value for SA-induced hypotension than baseline sitting and baseline supine with comparable prediction ability between Δ PI and r PI.

An evaluation of resolution, accuracy, and precision in FT-IR spectroscopy

Infrared spectroscopy is a foundational technique for the elucidation of chemical structures. The advancements in interferometric spectroscopy, and specifically the development of Fourier transform infrared (FT-IR) spectroscopy, are responsible for the widespread usage of IR spectrometers ranging from teaching labs to pharmaceutical quality control. FT-IR affords an excellent signal-to-noise ratio that permits sensitive sampling with quantitative accuracy and high wavenumber precision based on well documented advantages (Jacquinot, Fellgett, Connes). However, the effect of resolution and instrument-to-instrument variation on wavenumber accuracy is not well understood, with previous work grossly overestimating error. Here, a recommendation of wavenumber accuracy as a function of spectral resolution, accounting for instrument variation among leading manufacturers, is given based on an experimental study of polystyrene and acetaminophen. For peaks that are well resolved and not saturated, the position can be known within 1.1 cm−1 at a spectral resolution of 4 cm−1 or higher, and within 2.2 cm−1 at 8 cm−1 resolution. Other sources of variation are also discussed (e.g., poorly resolved peaks, peak saturation, water interference, spectral noise) to give general recommendations on when IR peak positions can be considered significantly different. Such guidelines are critical for interpreting subtle positional variations, as are often present in different crystal forms of pharmaceuticals.

EXAGGERATED CAECUM WITH ABERRANT APPENDIX- A CASE REPORT

Introduction: Depending on shape, four types of caecum are known out of which exaggerated caecum is of rare type. In this type the right saccule of caecum overgrows and left saccule is atrophied. In normal anatomy the appendicular orifice is situated about 2.5 cm below and behind the ileocaecal Orifice. Methodology: The right iliac fossa was dissected to note for the position of Appendix with respect to iliocaecal junction in a formalin fixed cadaver. Result: An exaggerated caecum with aberrant appendix was found, with the base of appendix above the ileocaecal junction, a large right sacculation and an absent left sacculation of the Caecum was also observed. Conclusion: An exaggerated caecum in itself is uncommon but along with the positional variation in the base of appendix it becomes a rare finding. The knowledge about this variation will be useful to surgeons while operating in this region.

Patterns of Cross-Peaks in Two-Dimensional Correlation Spectra to Probe Intermolecular Interactions Described by Two Reversible Reactions.

Two-dimensional correlation spectroscopy is used to investigate the intermolecular interaction between two substances dissolved in the same solutions, where the intermolecular interaction is described by two reversible reactions producing two supramolecular aggregates. The severe overlappings expected among the characteristic peaks of the original solute and aggregates make conventional one-dimensional spectra difficult to accurately reflect the physiochemical nature of the intermolecular interaction. The double asynchronous orthogonal sample design (DAOSD) approach is utilized to analyze the simulated data for proof-of-principle demonstration. The patterns of cross-peaks are much more complex compared with the intermolecular interaction described by only a single reaction. Four major groups of cross-peaks with characteristic patterns observed in the pair of DAOSD asynchronous spectra are systematically analyzed and classified. Further analysis of the spectral feature of the cross-peaks of the DAOSD asynchronous spectra is helpful to exact additional information concerning the variation of the peak position and peak width of the aggregates compared with those of the original solute. The result is important to reveal the physicochemical nature of intermolecular interaction between the solutes (e.g., changes in conformation, dynamical behavior, etc.). The pattern of cross-peaks in the corresponding 2D asynchronous spectra may become rather complex when the peak position, peak width, and peak intensity of two supramolecular aggregates change simultaneously. Further work using artificial intelligence techniques to interpret the complex cross-peaks is still being carried out.

Center of mass position does not drive energetic costs during climbing.

Climbing animals theoretically should optimize the energetic costs of vertical climbing while also maintaining stability. Many modifications to climbing behaviors have been proposed as methods of satisfying these criteria, focusing on controlling the center of mass (COM) during ascent. However, the link between COM movements and metabolic energy costs has yet to be evaluated empirically. In this study, we manipulated climbing conditions across three experimental setups to elicit changes in COM position, and measured the impact of these changes upon metabolic costs across a sample of 14 humans. Metabolic energy was assessed via open flow respirometry, while COM movements were tracked both automatically and manually. Our findings demonstrate that, despite inducing variation in COM position, the energetic costs of climbing remained consistent across all three setups. Differences in energetic costs were similarly not affected by body mass; however, velocity had a significant impact upon both cost of transport and cost of locomotion, but such a relationship disappeared when accounting for metabolic costs per stride. These findings suggest that climbing has inescapable metabolic demands driven by gaining height, and that attempts to mitigate such a cost, with perhaps the exception of increasing speed, have only minimal impacts. We also demonstrate that metabolic and mechanical energy costs are largely uncorrelated. Collectively, we argue that these data refute the idea that efficient locomotion is the primary aim during climbing. Instead, adaptations towards effective climbing should focus on stability and reducing the risk of falling, as opposed to enhancing the metabolic efficiency of locomotion.

Evaluation of Diaphragm Position Variations During Proton Therapy for Pediatric Patients With Neuroblastoma.

Background To evaluate the respiratory-induced intrafractional diaphragm motion and interfractional diaphragm displacement in pediatric patients with neuroblastoma (NBL). Materials and methods Ten pediatric patients with a mean age of 4.5 years (range: 1.8-8.7 years) with abdominal NBL treated with proton therapy (PT) have been evaluated. Intrafractional motion and interfractional displacement have been analyzed by using cine radiography and orthogonal X-ray images, respectively. In each case, the cranio-caudal positions of the diaphragm have been measured as an index. This study has investigated the possible correlations between intrafractional diaphragm motion and height. Additionally, interfractional displacementand its time trend during the treatment course have been analyzed. Results The average right and left diaphragm intrafractional motions of 8.3 mm (range: 4.4-11.5 mm) and 6.4 mm (range: 2.2-11.8 mm) were observed, respectively; however, no significant correlation has been observed with height. An interfractional displacement of 5 mm or more has been observed in 20 out of 152 fractions (13%). The average absolute value of the interfractional displacement was 2.5 mm (range: 0-8.6 mm). Interfractional displacement did not show a peculiar tendency throughout the treatment period. Conclusions It was suggested that respiratory-induced diaphragm position variation in children varies greatly among individuals, and accurately estimating it based on height is difficult. Thus, these individual evaluations are considered indispensable.

Proposing candidate genes under telomeric control based on cross-species position data.

In this paper, we present a comprehensive computational framework aimed at suggesting genes whose transcriptional regulation is likely to be influenced by their chromosomal position. This framework provides a user-friendly web interface, enabling researchers to explore the positional properties of all human genes and their orthologs across species, with a focus on their relation to the telomeres. Our approach involves multiple scoring methods, each adjustable by users, representing different features of the genes' positional variation across species. The resulting rankings can be combined to identify candidate genes that may be subject to position effects. Furthermore, the ranking can be tailored to a specific set of reference genes. We evaluate the method within the context of TPE-OLD, a mechanism where telomeres can exert a direct influence on gene expression across considerable genomic distances, and empower researchers to delve deeper into genes of interest, analyzing their position across species and estimating their susceptibility to position effects like TPE-OLD. We also provide simple enrichment analyses of user-provided gene lists in relation to top-ranking candidate genes.

Localized region of Goos-Hänchen shifts in reflection and transmission based on position-dependent complex conductivity

The complex conductivity-dependent localized region of GH shift in transmission as well as reflection are controlled and modified with the position and parameters of deriving fields. The conductivity-dependent dielectric function and the conductivity-dependent refractive index are determined while using the density-matrix approach, Maxwell equations, and four-level conducting mediums. Using that refractive index, we determine the complex conductivity-dependent reflection as well as transmission, and related lateral shift in reflection and also transmission. Significant positive-negative GH-shift in the reflection as well as transmission are reported with variations in position and deriving fields. The normalization condition |R|+|T|=1 is satisfied for each point of the position and deriving field parameters. The maximum positive-negative GH shift in the reflection as well as transmission are computed to SR,T=±50λ. The maximum phase of reflection and transmission is calculated to ±500 microradian. The modified outcomes of this work are helpful in optical sensors as well as waveguide switching technologies.

Deep conditional generative model for longitudinal single-slice abdominal computed tomography harmonization.

Two-dimensional single-slice abdominal computed tomography (CT) provides a detailed tissue map with high resolution allowing quantitative characterization of relationships between health conditions and aging. However, longitudinal analysis of body composition changes using these scans is difficult due to positional variation between slices acquired in different years, which leads to different organs/tissues being captured. To address this issue, we propose C-SliceGen, which takes an arbitrary axial slice in the abdominal region as a condition and generates a pre-defined vertebral level slice by estimating structural changes in the latent space. Our experiments on 2608 volumetric CT data from two in-house datasets and 50 subjects from the 2015 Multi-Atlas Abdomen Labeling Challenge Beyond the Cranial Vault (BTCV) dataset demonstrate that our model can generate high-quality images that are realistic and similar. We further evaluate our method's capability to harmonize longitudinal positional variation on 1033 subjects from the Baltimore longitudinal study of aging dataset, which contains longitudinal single abdominal slices, and confirmed that our method can harmonize the slice positional variance in terms of visceral fat area. This approach provides a promising direction for mapping slices from different vertebral levels to a target slice and reducing positional variance for single-slice longitudinal analysis. The source code is available at: https://github.com/MASILab/C-SliceGen.

Acute Pericarditis Manifesting as Persistent Chest Pain Following Primary Percutaneous Coronary Intervention: A Missed Diagnosis

Percutaneous coronary intervention (PCI) is a very rare cause of acute pericarditis. It usually develops after a latent period but can present early in case of procedural complications. A high degree of suspicion is required for diagnosis as most cases can be easily missed. Here, we highlight a case of 54-year-old admitted as a case of non-ST elevated myocardial infarction who in view of ongoing chest pain underwent urgent coronary angiography, followed by the primary PCI to left anterior descending artery after which the patient became pain-free. However, 12 h after the procedure, the patient developed severe persistent chest pain with positional and respiratory variation. He was suspected to have reinfarction and treated accordingly but had no symptomatic improvement and was planned for check angiography. However, based on dynamic electrocardiogram (ECG) changes, new echocardiographic findings aided laboratory parameters, he was diagnosed with acute pericarditis. He was treated with nonsteroidal anti-inflammatory drugs following which his pain resolved and ECG returned to baseline after 4 days. His follow-up echocardiography showed complete resolution of pericardial effusion. This case highlights the importance of keeping acute pericarditis as a differential diagnosis of chest pain in PCI patients. A high degree of suspicion is required, as most cases are easily missed to diagnose.

Assessment of Mental Foramen Characteristics in Syrian Population Using Cone Beam Computed Tomography: A Pilot Study.

Background Knowledge of the mental foramen (MF) characteristics is crucial for avoiding iatrogenic injuries during dental implant placement, root canal treatment, orthognathic surgery, and other dental and surgical interventions. Cone beam computed tomography (CBCT) offers a valuable tool for evaluating the MF characteristics with its precise anatomical details. The current study investigates the horizontal and vertical position variations in addition to the exit angle of MF within the Syrian adult population. Materials and methods The sample included CBCT scans of 42 subjects with an equal number of males and females (21 males, 21 females), with no underlying pathology in the investigated region, mean age was 24.7 years (SD: 7.2 years). CBCT scans were retrospectively analyzed in terms of the vertical, horizontal, and exit angle direction of MF. The chi-square test was conducted to investigate statistical differences in terms of MF horizontal and vertical positions. A T-test was conducted to investigate statistical differences in terms of exit angle direction. Comparisons were conducted between males and females groups, and between the left and right sides in the total sample group. Results The most frequent horizontal position was position 3 (MF between the first and second premolars) on the right side (n=20, 47.61%), and on the left side (n=21, 50%). The most frequent vertical position was position 3 (MF below the apices of the premolars) on the right side (n=29, 69.04%), and on the left side (n=27, 64.28%).The exit angle of the MF was in a backward direction, with a mean value of 118.42° (SD: 6.45 degrees), and 115.97° (SD: 7.29 degrees) on the right and left side, respectively. Statistically significant differences were found in terms of the right vertical position between males and females (P value < 0.05). Conclusion Variations in MF characteristics exist in the Syrian population. Statistically significant differences were found in the right vertical position of MF. The current study findings necessitate precise preoperative three-dimensional imaging for dental interventions among this population. By establishing normative values for the Syrian population, the results can contribute to improved surgical planning and patient care, and can be used for comparative studies for more understanding of the human anatomical variations.

Evaluation of 3D C-Arm Fluoroscopy versus Diagnostic CT for Deep Brain Stimulation Stereotactic Registration and Post-Operative Lead Localization

Introduction: DBS efficacy depends on accuracy. CT-MRI fusion is established for both stereotactic registration and electrode placement verification. The desire to streamline DBS workflows, reduce operative time, and minimize patient transfers has increased interest in portable imaging modalities such as the Medtronic O-arm® and mobile CT. However, these remain expensive and bulky. 3D C-arm fluoroscopy (3DXT) units are a smaller and less costly alternative, albeit incompatible with traditional frame-based localization and without useful soft tissue resolution. We aimed to compare fusion of 3DXT and CT with pre-operative MRI to evaluate if 3DXT-MRI fusion alone is sufficient for accurate registration and reliable targeting verification. We further assess DBS targeting accuracy using a 3DXT workflow and compare radiation dosimetry between modalities. Methods: Patients underwent robot-assisted DBS implantation using a workflow incorporating 3DXT which we describe. Two intra-operative 3DXT spins were performed for registration and accuracy verification followed by conventional CT post-operatively. Post-operative 3DXT and CT images were independently fused to the same pre-operative MRI sequence and co-ordinates generated for comparison. Registration accuracy was compared to 15 consecutive controls who underwent CT-based registration. Radial targeting accuracy was calculated and radiation dosimetry recorded. Results: Data were obtained from 29 leads in 15 consecutive patients. 3DXT registration accuracy was significantly superior to CT with mean error 0.22 ± 0.03 mm (p < 0.0001). Mean Euclidean electrode tip position variation for CT to MRI versus 3DXT to MRI fusion was 0.62 ± 0.40 mm (range 0.0 mm–1.7 mm). In comparison, direct CT to 3DXT fusion showed electrode tip Euclidean variance of 0.23 ± 0.09 mm. Mean radial targeting accuracy assessed on 3DXT was 0.97 ± 0.54 mm versus 1.15 ± 0.55 mm on CT with differences insignificant (p = 0.30). Mean patient radiation doses were around 80% lower with 3DXT versus CT (p < 0.0001). Discussion: Mobile 3D C-arm fluoroscopy can be safely incorporated into DBS workflows for both registration and lead verification. For registration, the limited field of view requires the use of frameless transient fiducials and is highly accurate. For lead position verification based on MRI co-registration, we estimate there is around a 0.4 mm discrepancy between lead position seen on 3DXT versus CT when corrected for brain shift. This is similar to that described in O-arm® or mobile CT series. For units where logistical or financial considerations preclude the acquisition of a cone beam CT or mobile CT scanner, our data support portable 3D C-arm fluoroscopy as an acceptable alternative with significantly lower radiation exposure.

Grating-based metasurfaces for ultra-narrow near-infrared bandpass filtering with wide out-of-band suppression

Here, we present a straightforward strategy for designing silicon grating-based metasurfaces tailored for narrow near-infrared bandpass filtering. By selecting appropriate structural parameters for the grating and including periodic groove perturbations within each grating slit, transverse guided mode resonances (GMRs) propagating perpendicular and parallel to the grating slit are created to provide wide out-of-band suppression and high-Q filter responses, respectively. The destructive and constructive interference between radiations from groove perturbations are then introduced to eliminate all GMRs except one, producing a single-band bandpass filter. Simply adjusting the period of the groove perturbations allows precise tuning of the passband’s central wavelength across the operational spectral range from 1350 nm to 1750nm, throughout which the passband exhibits a Q-factor exceeding 9,000 and the attenuation level outside the passband remains below 1%. Furthermore, our proposed narrow bandpass filters are found to be robust against the potential fabrication imperfections, such as variations in groove size and position.

Multi-view orientational attention network combining point-based affinity for polyp segmentation

Most existing deep learning-based polyp segmentation methods neglect two important aspects of polyps: the geometric orientation information of polyps and the point information of the entire colonoscopy area. In this paper, we introduce a multi-view orientational attention network (MVOA-Net), which incorporates orientation and point awareness to effectively address the issue of intra-class inconsistency resulting from variations in polyp shape, size, and position, as well as the inter-class indistinction caused by the high similarity between polyp lesions and surrounding tissues. To achieve robust orientation awareness, we propose a novel geometric orientation transformer encoder (GOTE) based on horizontal and vertical views. Moreover, To simultaneously capture the global context information of GOTE and emphasize the important local information of the convolution-based attention encoder (CBAE), a global and local cross attention fusion module (CAFM) is also proposed to simultaneously model the long-range dependencies of polyps and pay sufficient attention to the local boundaries of polyps. Additionally, a efficient atrous spatial pyramid pooling (E-ASPP) module is proposed to enhance the semantic representation of high-level features. Finally, a point-based affinity module (PBAM) and a multi-scale fusion module (MSFM) are proposed to distinguish the disguise of polyps, further alleviating inter-class indistinction. The ablation study results demonstrate the effectiveness of each component. Quantitative and qualitative experimental results show that MVOA-Net achieves the best segmentation accuracy across domain polyp datasets and has obvious advantages in segmenting multiple polyp objects.

Clinical practicality and patient performance for surface-guided automated VMAT gating for DIBH breast cancer radiotherapy

Background and purposeTo evaluate the performance of automated surface-guided gating for left-sided breast cancer with DIBH and VMAT. Materials and methodsPatients treated in the first year after introduction of DIBH with VMAT were retrospectively considered for analysis. With automated surface-guided gating the beam automatically switches on/off, if the surface region of interest moved in/out the gating tolerance (±3 mm, ±3°). Patients were coached to hold their breath as long as comfortably possible. Depending on the patient’s preference, patients received audio instructions during treatment delivery. Real-time positional variations of the breast/chest wall surface with respect to the reference surface were collected, for all three orthogonal directions. The durations and number of DIBHs needed to complete dose delivery, and DIBH position variations were determined. To evaluate an optimal gating window threshold, smaller tolerances of ±2.5 mm, ±2.0 mm, and ±1.5 mm were simulated. Results525 fractions from 33 patients showed that median DIBH duration was 51 s (range: 30–121 s), and median 4 DIBHs per fraction were needed to complete VMAT dose delivery. Median intra-DIBH stability and intrafractional DIBH reproducibility approximated 1.0 mm in each direction. No large differences were found between patients who preferred to perform the DIBH procedure with (n = 21) and without audio-coaching (n = 12). Simulations demonstrated that gating window tolerances could be reduced from ±3.0 mm to ±2.0 mm, without affecting beam-on status. ConclusionIndependent of the use of audio-coaching, this study demonstrates that automated surface-guided gating with DIBH and VMAT proved highly efficient. Patients’ DIBH performance far exceeded our expectations compared to earlier experiences and literature. Furthermore, gating window tolerances could be reduced.

Exploring the utility of Geometric Morphometrics to analyse prehistoric hand stencils

Hand stencils are a remarkable graphic expression in Prehistoric rock art, dating back to 42 ka BP. Although these stencils provide direct impressions of the artists’ hands, the characterization of their biological profile (i.e., biological sex and age) is very challenging. Previous studies have attempted this analysis with traditional morphometrics (TM), whereas little research has been undertaken using Geometric Morphometrics (GM), a method widely used in other disciplines but only tentatively employed in rock art studies. However, the large variation in relative finger position in archaeological hands poses the question of whether these representations can be examined through GM, or, in contrast, if this creates an unmanageable error in the results. To address this issue, a 2D hand scans sample of 70 living individuals (F = 35; M = 35) has been collected in three standardized positions (n = 210) and digitized with 32 2D conventional landmarks. Results show that the intra-individual distance (mean Procrustes distance between Pos. 1–2 = 0.132; 2–3 = 0.191; 1–3 = 0.292) is larger than the inter-individual distance (mean in 1 = 0.122; 2 = 0.142; 3 = 0.165). Finally, it has been demonstrated that the relative finger positions, as well as the inclusion of all hand parts in the analysis, have an overshadowing effect on other variables potentially involved in the morphometric variability of the hand, such as biological sex.