133 research outputs found

    Torso shape detection to improve lung monitoring

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    Two methodologies are proposed to detect the patient-specific boundary of the chest, aiming to produce a more accurate forward model for EIT analysis. Thus, a passive resistive and an inertial prototypes were prepared to characterize and reconstruct the shape of multiple phantoms. Preliminary results show how the passive device generates a minimum scatter between the reconstructed image and the actual shap

    Torso shape detection to improve lung monitoring

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    Newborns with lung immaturity often require continuous monitoring and treatment of their lung ventilation in intensive care units, especially if born preterm. Recent studies indicate that Electrical Impedance Tomography (EIT) is feasible in newborn
 infants and children, and can quantitatively identify changes in regional lung aeration and ventilation following alterations to respiratory conditions. Information on the patient-specic shape of the torso and its role in minimizing the artefacts in the
 reconstructed images can improve the accuracy of the clinical parameters obtained from EIT. Currently, only idealized models or those segmented from CT scans are usually adopted. This study presents and compares two methodologies that can
 detect the patient-specic torso shape by means of wearable devices based on: (1) previously reported bend sensor technology and (2) a novel approach based on the use of accelerometers. The reconstruction of different phantoms, taking into account
 anatomical asymmetries and different sizes, are produced for comparison. As a result, the accelerometers are more versatile than bend sensors, which cannot be used on bigger cross-sections. The computational study estimates the optimal number of
 accelerometers required in order to generate an image reconstruction comparable to the use of a CT scan as the forward model. Furthermore, since the patient position is crucial to monitoring lung ventilation, the orientation of the phantoms is automatically
 detected by the accelerometer-based method. [Abstract copyright: © 2018 Institute of Physics and Engineering in Medicine.

    Cross-sectional chest circumference and shape development in infants

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    Objective: This study investigates the development of the thoracic cross-section at the nipple line level during the early stages of life. Unlike the descriptive awareness regarding chest development course, there exist no quantitative references concerning shape, circumference and possible dependencies to age, gender or body weight. The proposed mathematical relations are expected to help create guidelines for more realistic modelling and potential detection of abnormalities. One potential application is lung electrical impedance tomography (EIT) monitoring where accurate chest models are crucial in both extracting reliable parameters for regional ventilation function and design of EIT belts. Despite their importance, such reference data is not readily available for the younger age range due to insufficient data amid the regulations of neonatal imaging. Results: Chest circumference shows the highest correlation to body weight following the relation fx=18.3735ln0.0012x+2.1010 where x is the body weight in grams and f(x) is the chest circumference in cm at the nipple line level. No statistically significant difference in chest circumference between genders was detected. However, the shape indicated signs of both age and gender dependencies with on average boys developing a more rectangular shape than girls from the age of 1 years and 9 months

    Towards a thoracic conductive phantom for EIT

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    Phantom experiments are a crucial step for testing new hardware or imaging algorithms for electrical impedance tomography (EIT) studies. However, constructing an accurate phantom for EIT research remains critical; some studies have attempted to model the skull and breasts, and even fewer, as yet, have considered the thorax. In this study, a critical comparison between the electrical properties (impedance) of three materials is undertaken: a polyurethane foam, a silicone mixture and a thermoplastic polyurethane filament. The latter was identified as the most promising material and adopted for the development of a flexible neonatal torso. The validation is performed by the EIT image reconstruction of the air filled cavities, which mimic the lung regions. The methodology is reproducible for the creation of any phantom that requires a slight flexibility

    Trimerisation of carbon suboxide at a di-titanium centre to form a pyrone ring system

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    The reaction of the syn-bimetallic bis(pentalene)dititanium complex Ti2(μ:η5,η5-Pn†)2 (Pn† = C8H4(1,4-SiiPr3)2) 1 with carbon suboxide (O[double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash]O, C3O2) results in trimerisation of the latter and formation of the structurally characterised complex [{Ti2(μ:η5,η5-Pn†)2}{μ-C9O6}]. The trimeric bridging C9O6 unit in the latter contains a 4-pyrone core, a key feature of both the hexamer and octamer of carbon suboxide which are formed in the body from trace amounts of C3O2 and are, for example, potent inhibitors of Na+/K+-ATP-ase. The mechanism of this reaction has been studied in detail by DFT computational studies, which also suggest that the reaction proceeds via the initial formation of a mono-adduct of 1 with C3O2. Indeed, the carefully controlled reaction of 1 with C3O2 affords [Ti2(μ:η5,η5-Pn†)2 (η2-C3O2)], as the first structurally authenticated complex of carbon suboxide

    Estimation of thorax shape for forward modelling in lungs EIT

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    The thorax models for pre-term babies are developed based on the CT scans from new-borns and their effect on image reconstruction is evaluated in comparison with other available models

    Model selection based algorithm in neonatal Chest EIT

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    This paper presents a new method for selecting a patient specific forward model to compensate for anatomical variations in electrical impedance tomography (EIT) monitoring of neonates. The method uses a combination of shape sensors and absolute reconstruction. It takes advantage of a probabilistic approach which automatically selects the best estimated forward model fit from pre-stored library models. Absolute/static image reconstruction is performed as the core of the posterior probability calculations. The validity and reliability of the algorithm in detecting a suitable model in the presence of measurement noise is studied with simulated and measured data from 11 patients. The paper also demonstrates the potential improvements on the clinical parameters extracted from EIT images by considering a unique case study with a neonate patient undergoing computed tomography imaging as clinical indication prior to EIT monitoring. Two well-known image reconstruction techniques, namely GREIT and tSVD, are implemented to create the final tidal images. The impacts of appropriate model selection on the clinical extracted parameters such as center of ventilation and silent spaces are investigated. The results show significant improvements to the final reconstructed images and more importantly to the clinical EIT parameters extracted from the images that are crucial for decision-making and further interventions

    Intramuscular vaccination of Atlantic lumpfish (Cyclopterus lumpus L.) induces inflammatory reactions and local immunoglobulin M production at the vaccine administration site

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    Atlantic lumpfish were vaccinated by intramuscular (im) or intraperitoneal (ip) injection with a multivalent oil‐based vaccine, while control fish were injected with phosphate‐buffered saline. Four lumpfish per group were sampled for skin/muscle and head kidney tissue at 0, 2, 7, 21 and 42 days post‐immunization (dpi) for histopathology and immunohistochemistry (IHC). Gene expressions of secretory IgM, membrane‐bound IgM, IgD, TCRα, CD3ε and MHC class IIβ were studied in tissues by using qPCR. Im. vaccinated fish showed vaccine‐induced inflammation with formation of granulomas and increasing number of eosinophilic granulocyte‐like cells over time. On IHC sections, we observed diffuse intercellular staining of secretory IgM at the injection site at 2 dpi, while IgM + cells appeared in small numbers at 21 and 42 dpi. Skin/muscle samples from im. vaccinated fish demonstrated an increase in gene expression of IgM mRNA (secretory and membrane‐bound) at 21 and 42 dpi and small changes for other genes. Our results indicated that im. vaccination of lumpfish induced local IgM production at the vaccine injection site, with no apparent proliferation of IgM + cells. Eosinophilic granulocyte‐like cells appeared shortly after im. injection and increased in numbers as the inflammation progressed.publishedVersio

    A Structurally Characterized Cobalt(I) σ-Alkane Complex

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    The synthesis, and x-ray structure, of a cobalt s -alkane complex, [Co(Cy 2 P(CH 2 ) 4 PCy 2 )( norbornane )][BAr F 4 ], is achieved by a single-crystal to single-crystal solid/gas hydrogenation from a norbornadiene precursor. Magnetic data show this complex to be a triplet. Periodic DFT and electronic structure analyses identify weak C-H ··· Co σ -interactions, augmented by dispersive stabilisation between the alkane ligand and the anion-microenvironment. The calculations are most consistent with a η 1 : η 1 -alkane binding mode
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