Scan Measurements Research Articles

Antigliadin antibodies and the brain in people without celiac disease: a case-control study.

Anti-gliadin antibodies (AGA) occur in approximately 10% of the general population, produced as a response to gluten. Autoimmune gluten-related disorders can have detrimental neurological effects if not properly controlled but the relevance of such "incidental" AGA is not properly established; any harm caused would indicate the gluten-free diet as a means for affected people to protect their brain health. We explored this question by comparing brain MRI scanning, cognitive testing and other measures between healthy volunteers with and without AGA. Healthy volunteers aged 50-70 (without celiac disease, on a gluten-containing diet) underwent blood testing to confirm AGA status. Any AGA+ subjects were matched to AGA- controls on age, sex, BMI, level of education, hypertension diagnosis and smoking history. These subgroups underwent a cognitive test battery, quality-of-life (QoL) surveys and brain MRI scanning. Groups were compared between all outcome measures. Secondary analyses correlated AGA titre with outcomes across the whole cohort. Groupwise comparisons of cognitive, QoL and MRI studies were all negative. Repeating these analyses as correlations with AGA titre across the cohort, a single significant result was found concerning the error rate on the subtle cognitive impairment test, in a direction indicating increased IgG AGA to predict worse performance. This did not survive multiple comparisons correction. Our analysis is the most comprehensive to date and utilises a number of outcome measures known to be sensitive to subtle shifts in neurophysiology and cognition. Incidental AGA does not appear to be associated with any indications of neuropsychological deficit.

Spray‐dried Ni‐Co Bimetallic Catalysts for Dry Reforming of Methane

AbstractDry reforming of methane (DRM) is an attractive reaction for synthesis gas production, since it converts two greenhouse gases into valuable chemical feedstock. Silica supported bimetallic catalysts with constant metal loading but varying Ni/Co ratios (xNi=1, 0.8, 0.6, 0.5, 0.4, 0.2, 0) were produced via spray‐drying for the application in DRM, aiming at the identification of compositions with superior activity. In this study, building block particles refer to an inert framework, supporting the catalyst. The elemental distribution of Si, Ni, and Co within such building block particles was evaluated using scanning transmission electron microscopy. Additionally, X‐ray diffraction and temperature‐programmed reduction experiments confirmed that Ni and Co initially exist in an oxidic state within the SiO2 framework after production and later transform into an alloyed metallic state upon reduction with hydrogen, as confirmed by X‐ray photoelectron spectroscopy. A systematic comparison of the activity over a temperature range (323–1150 K) was performed using temperature scanning measurements. The highest intrinsic activity was found with the bimetallic Ni40Co60 particles.

Research on the application of a dynamic programming method based on geodesic distance for path planning in Robot-Assisted laser scanning measurement of Free-Form surfaces

The use of robots equipped with 3D laser line scanners is currently one of the mainstream geometric measurement methods for free-form surfaces. The key to this technology is to plan an effective measurement path based on the geometric features of the surface. In order to improve the measurement efficiency, a new path planning method for free-form surface measurement is proposed. First, an algorithm is developed to adaptively generate sample points of the surface to be measured based on the geodesic distance. Then, the geometric length of the scanning measurement path and the amplitude variation of the Euler angle are used as the objective function, and the optimal robot scanning measurement path is generated by minimising the objective function based on a dynamic programming algorithm. Finally, experiments show that the scanning measurement path generated based on the proposed method can effectively improve the measurement efficiency compared with existing research methods.

Integration of Terrestrial Laser Scanning and field measurements data for tree stem volume estimation: Exploring parametric and non-parametric modeling approaches

Integration of Terrestrial Laser Scanning and field measurements data for tree stem volume estimation: Exploring parametric and non-parametric modeling approaches

P-747 Can patient self-scans using a home vaginal ultrasound device be used to monitor the ovarian stimulation in ART?

Abstract Study question Can patient self-scans with a home ultrasound device, with or without professional remote online guidance, be used for ovarian and endometrial monitoring during for ART? Summary answer Follicle number/size and endometrial thickness recorded from patients’ home ultrasound self-acquired scans, especially when guided online, corresponded with standard sonographies and aspirated oocyte yield. What is known already Follicle number and size are a key parameter for monitoring the ovarian stimulation and determining the time for triggering and OPU. The endometrial thickness (EMT) and pattern are important parameters associated with implantation and pregnancy. Both are measured repeatedly in serial sonographies during the ART cycles, imposing a significant burden of time, travel and cost on patients, while adding to the clinic’s workload. Patient self-scans with a home ultrasound device can potentially relief patient travel discomfort and the clinic’s patient congestion. Study design, size, duration Open label study performed during one IVF cycle. Participants were trained to visualize uterus and ovaries using the Pulsenmore FC device. After training the patients were randomized to two groups: independent use (IU-scans) or remote online guidance by a clinical sonographer (CG-scans). Before each in-clinic scan patients obtained and recorded their pelvic scan, which were read blindly and compared to the in-clinic scans for ovaries and uterus visualization, follicles number and size, and EMT. Participants/materials, setting, methods Patients without Mullerian or pelvic pathologies undergoing stimulation for IVF. Clinical decisions and triggering were based on individual considerations and the standard in-clinic ultrasound measurements. OPU was performed 36-38h after triggering. All ultrasound scans were analyzed for image quality, number and size of follicles and EMT and compared to the in-clinic scans as the gold standard (GS). Correlation was calculated based on the Spearman Correlation Factor (SCF). Patient satisfaction was measured using a questionnaire. Main results and the role of chance Twenty-four patients completed the study, 11-CG and 13-IU. Image quality score was>3 and adequate uterine visualization was achieved in 100% of the CG-scans and in 87% of the IU-scans. The right ovary was imaged in 100% of the CG-scans and 85.7% of the IU-scans. The left ovary in 97.4% of the CG-scans and 85.7% of the IU-scans. CG-scans AFC correlated better with the GS than IU-scans AFC (SCF 0.85vs.0.12). Correct identification of the first follicle>14mm was achieved in 100% of the CG-scans and in 92% of the IU-patients. Maximal EMT from CG-scans was better correlated with the GS than the IU-scans (SCF 0.64vs.0.46), with a clinically insignificant difference (0.4mm). The number of stimulated follicles obtained from CG-scans was better correlated with the GS than IU-scans (SCF 0.94 vs.0.43). The oocytes/stimulated follicles ratio was 1.19 for the GS and 1.28 for the self scans (1.06 for CG-scans, 1.9 for IU-scans). The MII/follicles>14mm ratio was 1.12 for the GS and 1.49 for the self scans (1.27 for CG-scans,1.69 for IU-scans). Patients’ questionnaire revealed that 89% of patients felt comfortable to self-scan themselfs, 86.5% were interested to use the device and 75% will recommend it to their friends. Limitations, reasons for caution Self vaginal ultrasound scanning is not suitable for all patients and online support by a sonographer is required. Inter-observer differences in scan measurements should be taken into consideration. Since participation in the study was limited to one cycle, no patient learning curve for IU-scans could be evaluated. Wider implications of the findings Reliable folliculometry and endometrial measurements can be obtained from patient self-use vaginal ultrasound scans. Online assistance enhances scanning accuracy. Together with near/home lab tests, safe remote management of ovarian stimulation can be realized, reducing costs, discomfort and travel time, ultimately reducing workload for fertility clinics, and improving workforce flexibility. Trial registration number NCT05485623

Practical Aspects of Using Modern Laser Scanning Techniques for Measuring Mine Excavations

Abstract For more than a dozen or so years now, there has been growing interest in the use of modern laser scanning measurement methods in numerous mining operations engaged in underground excavation. However, the simple possession of a scanner does not guarantee satisfactory measurement results. This study sets out the results of scanning mine excavations in an active mine and describes the current guidelines on various aspects of the measurement process. These guidelines were developed on the basis of several hundred measurements carried out over the last dozen or so years. This study also outlines the typical measurements errors observed over the course of many years. These errors, resulting partly from hardware limitations and partly from human error when planning or actually performing measurements, were an important factor behind the introduction of standards regulating underground measurements. This study discusses in detail not only scanning that utilises traditional stationary laser scanners but also scanning based on mobile scanners. It also presents possible areas of future technological development in line with global trends.

Late-onset temporal lobe epilepsy: insights from brain atrophy and Alzheimer's disease biomarkers.

Considering the growing age of the world population, the incidence of epilepsy in older adults is expected to increase significantly. It has been suggested that late-onset temporal lobe epilepsy (LO-TLE) may be neurodegenerative in origin and overlap with Alzheimer's Disease (AD). Herein, we aimed to characterize the pattern of cortical atrophy and cerebrospinal fluid (CSF) biomarkers of AD (total and phosphorylated tau, and β-amyloid) in a selected population of LO-TLE of unknown origin. We prospectively enrolled individuals with temporal lobe epilepsy onset after the age of 50 and no cognitive impairment. They underwent a structural MRI scan and CSF biomarkers measurement. Imaging and biomarkers data were compared to three retrospectively collected groups: (i) age-sex-matched healthy controls, (ii) patients with Mild Cognitive Impairment (MCI) and abnormal CSF AD biomarkers (MCI-AD), and (iii) patients with MCI and normal CSF AD biomarkers (MCI-noAD). From a pool of 52 patients, twenty consecutive eligible LO-TLE patients with a mean disease duration of 1.8 years were recruited. As control populations, 25 patients with MCI-AD, 25 patients with MCI-noAD, and 25 healthy controls were enrolled. CSF biomarkers returned normal values in LO-TLE, significantly different from patients with MCI due to AD. There were no differences in cortico-subcortical atrophy between epilepsy patients and healthy controls, while patients with MCI demonstrated widespread injuries of cortico-subcortical structures. Individuals with a late-onset form of temporal lobe epilepsy, characterized by short disease duration and normal CSF β-amyloid and tau protein levels, showed patterns of cortical thickness and subcortical volumes not significantly different from healthy controls, but highly different from patients with MCI, either due to Alzheimer's Disease or not.

Study on Dynamic Scanning Trajectory of Large Aerospace Parts Based on 3D Scanning

The aim of manufacturing large aerospace parts for the three-dimensional scanning field demands high precision and efficiency. However, it may be more challenging to meet the full coverage of the measurement problems for large aerospace parts with the scanning range of traditional three-dimensional scanning methods. This paper establishes a dynamic posturing scanning measurement system for large aerospace parts with a six-degree-of-freedom posturing platform and a six-degree-of-freedom industrial robot linkage. It establishes a mathematical model of dynamic three-dimensional scanning posturing. It proposes a platform attitude adjustment strategy based on the field of view angle of a 3D scanner during the adjustment of a six-degree-of-freedom platform. The dynamic scanning path planning is carried out using the three-dimensional spatial decomposition method, and the vector coordinates of the critical points at the edges of the missing areas of the scan are used to re-scan the missing areas to establish the dynamic scanning paths of large aerospace parts. It is experimentally verified that the system can realize the dynamic scanning of complex curved large aerospace parts. The experimental results show that the measurement efficiency is improved by more than 75%, and the point cloud coverage of the scanning reconstruction is improved by 18% for large aerospace components with complex surfaces.

Correlation between degeneration of cervical intervertebral disc and degeneration of paravertebral muscle.

To investigate the relationship between degeneration of cervical intervertebral disc and degeneration of paravertebral muscles[multifidus (MF), cervical semispinalis (SCer), semispinalis capitis (SCap) and splenius capitis (SPL)]. 82 patients with chronic neck pain were randomly selected, including 43 males and 39 females, with 50.73 0.7.51 years old. All patients were scanned by 3.0T MRI Philips Ingenia performed conventional MRI sequence scanning and fat measurement sequence mDIXON-Quant scanning of cervical. Fat infiltration (FI) and cross-sectional area (CSA) of cervical paravertebral muscle (MF, SCer, SCap and SPL) at central level of C5-6 disc were measured by Philips 3.0T MRI image post-processing workstation. According to Pfirrmann grading system, there was no grade I in the included cases. The number of grade IIr IV cases were n=16, 40, 19 and 7 respectively. CSA and FI of cervical paravertebral muscles were compared with t test or one-way ANOVA, Spearman correlation analysis was used to evaluate the correlation between age, disc degeneration, and CSA, FI of cervical paravertebral muscles, and multiple linear regression analysis was used to analyze the independent influencing factors of CSA and FI. CSA of cervical paravertebral muscles in male patients was significantly higher than that in female patients (all P<0.001), but there was no significant difference in FI (all P>0.05). Age was weakly correlated with CSA of MF+SCer, moderately correlated with CSA of SCap and SPL (r=-0.256, -0.355 and -0.361, P<0.05), weakly correlated with FI of SCap and SPL (r= 0.182 and 0.264, P<0.001), moderately correlated with FI of MF+SCer (r=0.408, P<0.001). There were significant differences in FI with disc degeneration (P<0.001, P=0.028 and P=0.005). Further correlation analysis showed that disc degeneration was strongly correlated with FI of MF+SCer (r=0.629, P<0.001), and moderately correlated with FI of SCap and SPL (r=0.363, P=0.001; r=0.345, P=0.002). Multiple linear regression analysis showed that sex and age were the influencing factors of CSA of SCap and SPL, sex was the independent influencing factor of CSA of MF+SCer, and disc degeneration was the independent influencing factor of FI. Age is negatively correlated with CSA and positively correlated with FI. Disc degeneration was correlated with FI of paravertebral muscles, especially with FI of MF and SCer. Sex and age were the influencing factors of CSA, while disc degeneration was the independent influencing factor of FI.

Alterations in DNA methylation machinery in a rat model of osteoarthritis of the hip

BackgroundThis study aimed to validate alterations in the gene expression of DNA methylation-related enzymes and global methylation in the peripheral blood mononuclear cell (PBMC) and synovial tissues of animal hip osteoarthritis (OA) models.MethodsAnimals were assigned to the control (no treatment), sham (25 µL of sterile saline), and OA (25 µL of sterile saline and 2 mg of monoiodoacetate) groups. Microcomputed tomography scan, histopathological assessment and pain threshold measurement were performed after induction. The mRNA expression of the DNA methylation machinery genes and global DNA methylation in the PBMC and hip synovial tissue were evaluated.ResultsThe OA group presented with hip joint OA histopathologically and radiologically and decreased pain threshold. The mRNA expression of DNA methyltransferase (Dnmt 3a), ten–eleven translocation (Tet) 1 and Tet 3 in the synovial tissue of the OA group was significantly upregulated. Global DNA methylation in the synovial tissue of the OA group was significantly higher than that of the control and sham groups.ConclusionsThe intra-articular administration of monoiodoacetate induced hip joint OA and decreased pain threshold. The DNA methylation machinery in the synovial tissues of hip OA was altered.

Comparative Study for Surgical Treatment of Acute Distal Tibiofibular Syndesmotic Lesions Using the Modified Suture-Button Fixation Versus Static Syndesmotic Screw Fixation.

Several techniques to treat acute distal tibiofibular instability are described consisting in static and dynamic fixation procedures. The aim of our work is to compare the outcomes of acute syndesmotic injury fixation between the modified technique of dynamic fixation using the suture-button principle as an efficient and low-cost method and the classic static fixation. It is a prospective study including patients presenting with acute syndesmotic injury. After fracture fixation, residual syndesmotic instability was managed using syndesmotic screw in group A and dynamic fixation with a double Ethibond suture in group B. Functional results were assessed using the American Orthopaedic Foot and Ankle Society score (AOFAS) score. Radiological evaluation was done by a postoperative computed tomography (CT) scan of both ankles and plain X-rays of the ankle after surgery and at 18 months. Group A included 20 patients meanwhile 35 patients were in group B. The reduction was satisfactory in the 2 groups according to the postoperative CT scan measurements. The mean healing time in group A was 49.65 days and 51.49 days in group B (P = .45). We did not find any significant difference in terms of loss of reduction in the 2 groups. The return to work was faster in group B (P = .04). Patients in group B had better AOFAS score (P = .03) and ankle range of motion than those in group A. The difference was statistically significant (P = .02 for dorsal flexion and P = .001 for plantar flexion). For group A, we did not note any early complications. Meanwhile, 7 patients developed skin complications in group B (P = .03). However, no significant difference was found in terms of late complications. The modified dynamic suture-button fixation remains a therapeutic alternative in low-income countries that could achieve better outcomes than static fixation, with easy postoperative follow-up. Level II.

Simultaneous electromagnetic field probing system with Y‐shaped separation detection structure

AbstractSimultaneous electromagnetic field probing system (SEMPS) has been popular in recent years. Herein, a simultaneous electromagnetic field probing system with Y‐shaped separation detection structure (SEMPS Y) is first proposed, in which the electric field probing region and the magnetic field probing region of the probe are separated by completely covering the shield along the loop and adding a pin‐shaped metal wire to capture the electric field, which are not the same as the classical dual probe structure. Combined with the non‐rotating asymmetric calibration method (NRACM), a 4‐port vector network analyser (VNA) and a highly symmetric grounded coplanar waveguide (GCPW) calibrator are used to solve the calibration matrix of the asymmetric SEMPS Y. The high symmetry GCPW calibrator is used to generate the standard electromagnetic field for calibration. The results of standing wave measurements show that the SEMPS Y can achieve ultrawideband electromagnetic field measurement of up to 20 GHz. Based on near‐field scanning measurements, SEMP Y can obtain results consistent with the calculation. In addition, when the probe is rotated 90° to invalidate the H‐field input, the decoupling curves of E‐field and H‐field are measured. Results show that the separation detection structure can effectively solve the cross‐coupling problem.

Production and characterisation of microfluidized olive powder

SummaryMicrofluidization has been gaining popularity as a size reduction process in recent years. In this study, microfluidization technique was used for olives to change the cell wall structure and decrease the size of oil droplets. Olive powders were produced from green, black and raw olives using freeze drying following microfluidization at 1200 bar. Antioxidant activity was not affected significantly for all powders while total phenolic content decreased for green and raw olive powders with microfluidization. Among all olive powders, the one raw olive gave the highest antioxidant activity and phenolic content. In microscopic analysis, Scanning Electron Microscope images revealed that microfluidization results in finer particles which are self‐encapsulated by trapping the oil droplets. Stability analysis through Turbi Scan and rheological measurements of the powder suspensions showed that microfluidization process enables more stable suspensions having higher water holding capacity. Herschel–Bulkley model was found for the flow behaviours of the olive powder suspensions.

Proscan: a structure-based proline design web server.

The ability to control protein conformations and dynamics through structure-based design has been useful in various scenarios, including engineering of viral antigens for vaccines. One effective design strategy is the substitution of residues to proline amino acids, which due to its unique cyclic side chain can favor and rigidify key backbone conformations. To provide the community with a means to readily identify and explore proline designs for target proteins of interest, we developed the Proscan web server. Proscan provides assessment of backbone angles, energetic and deep learning-based favorability scores, and other parameters for proline substitutions at each position of an input structure, along with interactive visualization of backbone angles and candidate substitution sites on structures. It identifies known favorable proline substitutions for viral antigens, and was benchmarked against datasets of proline substitution stability effects from deep mutational scanning and thermodynamic measurements. This tool can enable researchers to identify and prioritize designs for prospective vaccine antigen targets, or other designs to favor stability of key protein conformations. Proscan is available at: https://proscan.ibbr.umd.edu.

Tree growth potential and its relationship with soil moisture conditions across a heterogeneous boreal forest landscape

Forest growth varies across landscapes due to the intricate relationships between various environmental drivers and forest management. In this study, we analysed the variation of tree growth potential across a landscape scale and its relation to soil moisture. We hypothesised that soil moisture conditions drive landscape-level variation in site quality and that intermediate soil moisture conditions demonstrate the highest potential forest production. We used an age-independent difference model to estimate site quality in terms of maximum achievable tree height by measuring the relative change in Lorey’s mean height for a five year period across 337 plots within a 68 km2 boreal landscape. We achieved wall-to-wall estimates of site quality by extrapolating the modelled relationship using repeated airborne laser scanning data collected in connection to the field surveys. We found a clear decrease in site quality under the highest soil moisture conditions. However, intermediate soil moisture conditions did not demonstrate clear site quality differences; this is most likely a result of the nature of the modelled soil moisture conditions and limitations connected to the site quality estimation. There was considerable unexplained variation in the modelled site quality both on the plot and landscape levels. We successfully demonstrated that there is a significant relationship between soil moisture conditions and site quality despite limitations associated with a short study period in a low productive region and the precision of airborne laser scanning measurements of mean height.

Automating Linear and Angular Measurements for the Hip and Knee After Computed Tomography: Validation of a Three-Stage Deep Learning and Computer Vision-Based Pipeline for Pathoanatomic Assessment

BackgroundVariability in the bony morphology of pathologic hips/knees is a challenge in automating preoperative computed tomography (CT) scan measurements. With the increasing prevalence of CT for advanced preoperative planning, processing this data represents a critical bottleneck in presurgical planning, research, and development. The purpose of this study was to demonstrate a reproducible and scalable methodology for analyzing CT-based anatomy to process hip and knee anatomy for perioperative planning and execution. MethodsOne hundred patients with preoperative CT scans undergoing total knee arthroplasty for osteoarthritis were processed. A two-step deep learning pipeline of classification and segmentation models was developed that identifies landmark images and then generates contour representations. We utilized an open-source computer vision library to compute measurements. Classification models were assessed by accuracy, precision, and recall. Segmentation models were evaluated using dice and mean Intersection over Union (IOU) metrics. Contour measurements were compared against manual measurements to validate posterior condylar axis angle, sulcus angle, trochlear groove-tibial tuberosity distance, acetabular anteversion, and femoral version. ResultsClassifiers identified landmark images with accuracy of 0.91 and 0.88 for hip and knee models, respectively. Segmentation models demonstrated mean IOU scores above 0.95 with the highest dice coefficient of 0.957 [0.954-0.961] (UNet3+) and the highest mean IOU of 0.965 [0.961-0.969] (Attention U-Net). There were no statistically significant differences for the measurements taken automatically vs manually (P > 0.05). Average time for the pipeline to preprocess (48.65 +/− 4.41 sec), classify/retrieve landmark images (8.36 +/− 3.40 sec), segment images (<1 sec), and obtain measurements was 2.58 (+/− 1.92) minutes. ConclusionsA fully automated three-stage deep learning and computer vision-based pipeline of classification and segmentation models accurately localized, segmented, and measured landmark hip and knee images for patients undergoing total knee arthroplasty. Incorporation of clinical parameters, like patient-reported outcome measures and instability risk, will be important considerations alongside anatomic parameters.

High entropy alloys (FeCoNi)0.75Cr0.25-xCux – thermal stability and physical properties

The paper reports on the phase stability of the (FeCoNi)0.75Cr0.25-xCux HEA system with equimolar ratio of Fe, Co and Ni by differential scanning calorimetry (DSC) and measurements of physicochemical properties: density, electrical resistivity, Seebeck coefficient, thermal conductivity, and magnetic behaviour in a broad temperature region as well as hardness and elastic modulus at room temperature as a function of the gradual substitution of chromium by copper in a series of (FeCoNi)0.75Cr0.25-xCux alloys with different mole fraction of Cu (x = 0, 0.05, 0.1, 0.15 and 0.2). DSC measurements showed that all alloys are thermally stable. Increasing content of Cu was found (i) to increase the formation of a fcc Cu-rich phase, (ii) to strengthen ferromagnetic interactions, resulting in rising ordered magnetic moments, as well as in growing ferromagnetic transition temperatures, and (iii) to distinctly change physical properties like electrical resistivity, thermal expansion, and mechanical properties. Experimental data regarding the phase stability are supported by CALPHAD calculations.

Accuracy enhancement and joint calibration method of multi-station triangulation network based on absolute ranging

Precision measurement methods and technologies for large-scale three-dimensional coordinates are in high demand in advanced equipment manufacturing. The multi-station triangulation network represented by the rotary-laser scanning measurement system has the advantages of having high precision, having multitask parallel measurement capability, and having a high degree of automation. It is widely used in the docking of large components, quality control of key points, and collaborative positioning of production equipment. Nevertheless, due to the limitations in the measurement principle, the positioning accuracy along the depth direction is notably lower when compared to other directions. This difference becomes more pronounced with increasing distance. This paper proposes a method to address this issue by integrating a distance measurement station into the network. A novel, to the best of our knowledge, cooperative target, coupled with a high-dynamic beam guidance mechanism, is designed to achieve fast absolute distance measurement to the target. The weighted fusion of the distance and angle observations effectively enhances the measurement accuracy while preserving the advantages of highly automated measurement. Additionally, we introduce a joint calibration method for extrinsic parameters of multi-type stations. High-precision absolute distances are utilized to establish optical scale bars, complemented by the incorporation of physical scale bars, thereby obviating the necessity for using external reference instruments such as laser trackers. Finally, a series of experimental verifications demonstrate the effectiveness of calibration and measurement methods. The root mean square error of all measured points drop to 42.6% of that the triangulation method measures.

Double lumen endobronchial tube intubation: lessons learned from anatomy

BackgroundDouble lumen endobronchial tubes (DLTs) are frequently used to employ single lung ventilation strategies during thoracic surgical procedures. Placement of these tubes can be challenging even for experienced clinicians. We hypothesized that airway anatomy, particularly of the glottis and proximal trachea, significantly impacts the ease or difficulty in placement of these tubes.MethodsImages from 24 randomly selected Positron Emission Tomography – Computed Tomography (PET-CT) scans were evaluated for several anatomic aspects of the upper airway, including size and angulation of the glottis and proximal tracheal using calibrated CT measurements and an online digital protractor. The anatomic issues identified were confirmed in cadaveric anatomic models.ResultsProximal tracheal diameter measurements in PET-CT scans demonstrated a mean ± standard deviation of 20.4 ± 2.5 mm in 12 males and 15.5 ± 0.98 mm in 12 females (p < 0.001), and both were large enough to accommodate 39 French and 37 French DLTs in males and females, respectively. Subsequent measurements of the posterior angulation of the proximal trachea revealed a mean angle of 40.8 ± 5.7 degrees with no sex differences. By combining the 24 individual posterior tracheal angles with the 16 angled distal tip measurements DLTs (mean angle 24.9 ± 2.1 degrees), we created a series of 384 patient intubation angle scenarios. This data clearly showed that DLT rotation to a full 180 degrees decreased the mean intubation angle between the DLT and the proximal trachea from a mean of 66.6 ± 5.9 to only 15.8 ± 5.9 degrees.ConclusionsRotation of DLTs a full 180 instead of the recommended 90 degrees facilitates DLT intubations.

Inkjet printed acrylate-urethane modified poly(3,4-ethylenedioxythiophene) flexible conductive films

Abstract Flexible electronics is a new generation of electronic devices in which electronic components are integrated into flexible substrates. It is used in the fabrication of displays, solar cells, integrated circuits, and increasingly in the fabrication of electronic skin (E-skin), which can mimic the properties of human skin by being able to follow skin movements and flexures without loss of mechanical and electrical properties. E-skin is suitable for integrating various sensors to monitor personal health. Conductive polymers are used in flexible electronics due to their electrical conductivity, low mass, and stability. However, their main disadvantage is their brittleness, which is why they don’t possess flexibility property without modification. Therefore, in this work, the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) was used as the main chain and the side branches of poly(acrylate-urethane) (PAU) were grafted onto it by atom transfer radical polymerization (ATRP) onto it, obtaining the grafted copolymer PEDOT-g-PAU. In this way, the main chain of PEDOT retains the property of electrical conductivity without losing conjugation, while the side branches of PAU have the ability to crosslink non-covalently through hydrogen bonds with PAU side branches of adjacent polymer molecules due to the presence of oxygen in their structure. The presence of hydrogen bonds allows increasing the stretchability and flexibility of the material, and they also have the ability to spontaneously renew themselves when they break due to excessive stress. Three different synthesis conditions were used to obtain polymers of different structure, which were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and measurement of electrical conductivity with a four-point probe (4PP) method. The obtained graft copolymer was prepared in the form of ink and printed on a polyurethane (PU) substrate using inkjet technique. The conductivity of the printed layer, its elongation and adhesion were investigated, while possible delamination of the printed polymer layer was also monitored. The results showed that the PEDOT-g-PAU copolymer was successfully synthesized and inkjet printing on PU film was successful. The obtained material has satisfactory electrical and mechanical properties and could be used for the integration of fully functional biosensors with further optimization of the composition.