64 research outputs found

    Hysteresis-type electronic controlling device for fuel injectors and associated method

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    A hysteresis-type electronic controlling device is provided for fuel injectors that includes, but is not limited to a power driving unit for driving the fuel injectors with an electric signal, a control stage connected to the power driving unit and a sensing stage fed by the power driving unit and feeding the control stage, the device has a feedback frequency control stage for measuring a waveform period of the signal feeding the fuel injectors; the feedback frequency control stage is fed by the control stage with an electric signal. A fuel injector control method is also provided that includes, but is not limited to driving fuel injectors with an electric signal coming from a power driving unit fed by a control stage , sensing the signal with a sensing stage, and measuring a waveform period of the signal through the feedback frequency control stag

    Hysteresis-type electronic controlling device for fuel injectors and associated method

    Get PDF
    A hysteresis-type electronic controlling device is provided for fuel injectors that includes, but is not limited to a power driving unit for driving the fuel injectors with an electric signal, a control stage connected to the power driving unit and a sensing stage fed by the power driving unit and feeding the control stage, the device has a feedback frequency control stage for measuring a waveform period of the signal feeding the fuel injectors; the feedback frequency control stage is fed by the control stage with an electric signal. A fuel injector control method is also provided that includes, but is not limited to driving fuel injectors with an electric signal coming from a power driving unit fed by a control stage , sensing the signal with a sensing stage, and measuring a waveform period of the signal through the feedback frequency control stage

    Radio-Frequency Safety Assessment of Stents in Blood Vessels During Magnetic Resonance Imaging

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    Purpose: The purpose of this study was to investigate the need for high-resolution detailed anatomical modeling to correctly estimate radio-frequency (RF) safety during magnetic resonance imaging (MRI). RF-induced heating near metallic implanted devices depends on the electric field tangential to the device (Etan). Etan and specific absorption rate (SAR) were analyzed in blood vessels of an anatomical model to understand if a standard gel phantom accurately represents the potential heating in tissues due to passive vascular implants such as stents.Methods: A numerical model of an RF birdcage body coil and an anatomically realistic virtual patient with a native spatial resolution of 1 mm3 were used to simulate the in vivo electric field at 64 MHz (1.5 T MRI system). Maximum values of SAR inside the blood vessels were calculated and compared with peaks in a numerical model of the ASTM gel phantom to see if the results from the simplified and homogeneous gel phantom were comparable to the results from the anatomical model. Etan values were also calculated in selected stent trajectories inside blood vessels and compared with the ASTM result.Results: Peak SAR values in blood vessels were up to ten times higher than those found in the ASTM standard gel phantom. Peaks were found in clinically significant anatomical locations, where stents are implanted as per intended use. Furthermore, Etan results showed that volume-averaged SAR values might not be sufficient to assess RF safety.Conclusion: Computational modeling with a high-resolution anatomical model indicated higher values of the incident electric field compared to the standard testing approach. Further investigation will help develop a robust safety testing method which reflects clinically realistic conditions

    The Human Phenotype Ontology in 2024: phenotypes around the world

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    \ua9 The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research. The Human Phenotype Ontology (HPO) is a widely used resource that comprehensively organizes and defines the phenotypic features of human disease, enabling computational inference and supporting genomic and phenotypic analyses through semantic similarity and machine learning algorithms. The HPO has widespread applications in clinical diagnostics and translational research, including genomic diagnostics, gene-disease discovery, and cohort analytics. In recent years, groups around the world have developed translations of the HPO from English to other languages, and the HPO browser has been internationalized, allowing users to view HPO term labels and in many cases synonyms and definitions in ten languages in addition to English. Since our last report, a total of 2239 new HPO terms and 49235 new HPO annotations were developed, many in collaboration with external groups in the fields of psychiatry, arthrogryposis, immunology and cardiology. The Medical Action Ontology (MAxO) is a new effort to model treatments and other measures taken for clinical management. Finally, the HPO consortium is contributing to efforts to integrate the HPO and the GA4GH Phenopacket Schema into electronic health records (EHRs) with the goal of more standardized and computable integration of rare disease data in EHRs

    The Human Phenotype Ontology in 2024: phenotypes around the world.

    Get PDF
    The Human Phenotype Ontology (HPO) is a widely used resource that comprehensively organizes and defines the phenotypic features of human disease, enabling computational inference and supporting genomic and phenotypic analyses through semantic similarity and machine learning algorithms. The HPO has widespread applications in clinical diagnostics and translational research, including genomic diagnostics, gene-disease discovery, and cohort analytics. In recent years, groups around the world have developed translations of the HPO from English to other languages, and the HPO browser has been internationalized, allowing users to view HPO term labels and in many cases synonyms and definitions in ten languages in addition to English. Since our last report, a total of 2239 new HPO terms and 49235 new HPO annotations were developed, many in collaboration with external groups in the fields of psychiatry, arthrogryposis, immunology and cardiology. The Medical Action Ontology (MAxO) is a new effort to model treatments and other measures taken for clinical management. Finally, the HPO consortium is contributing to efforts to integrate the HPO and the GA4GH Phenopacket Schema into electronic health records (EHRs) with the goal of more standardized and computable integration of rare disease data in EHRs

    Effects of tuning conditions on near field of MRI transmit birdcage coil at 64 MHz

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    This study investigates how the tuning conditions of a 64 MHz / 1.5 T radio frequency (RF) birdcage coil modeled with an RF circuit and 3D electromagnetic co-simulation affect the electric and magnetic near-field distribution. Four models were implemented with different tuning conditions and difference between numerical results and measurements was evaluated. The results show that the simulated near-field depends significantly on coil tuning conditions, especially in volumes close to the ASTM phantom walls. Further extensive evaluations should be conducted to cover proper match between measurement and numerical result

    Effects of tuning conditions on near field of MRI transmit birdcage coil at 64 MHz

    No full text
    This study investigates how the tuning conditions of a 64 MHz / 1.5 T radio frequency (RF) birdcage coil modeled with an RF circuit and 3D electromagnetic co-simulation affect the electric and magnetic near-field distribution. Four models were implemented with different tuning conditions and difference between numerical results and measurements was evaluated. The results show that the simulated near-field depends significantly on coil tuning conditions, especially in volumes close to the ASTM phantom walls. Further extensive evaluations should be conducted to cover proper match between measurement and numerical result
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