In recent years, it was found that magnetostrictive ultrasonic guided wave transducers experimentally excited nonlinear harmonic components under a certain combination of dynamic and static magnetic fields. However, a satisfactory model for the relevant excitation mechanisms is not available. In this study, a new magnetostrictive guided wave excitation model was established and the causes for harmonics generation were analyzed. In addition, the calculation results of the model were obtained under different magnetic field parameters. We firstly changed the calculation conditions of magnetostrictive strain in the model and then theoretically calculated the odd and even harmonics of SH mode ultrasonic guided waves for the first time. Furthermore, the accuracy of the model was experimentally verified. By changing the strength ratio of the dynamic magnetic field to the static magnetic field (H/H), the excitation amplitudes of odd and even harmonics could be regulated with a magnetostrictive sensor. As the ratio of H/H increased, the normalized amplitude of the second harmonic firstly increased and then decreased, whereas the normalized amplitude of the third harmonic showed an exponential growth with different curvatures. This study enriched the theory of magnetostrictive guided wave excitation and provided a theoretical basis for the applications of magnetostrictive sensors.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.ultras.2024.107480 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Effect of Interventional Ultrasound in the Treatment of Postthyroidectomy Vocal Cord Dysfunction: A Preliminary Exploratory Study.
Ultrasound Med Biol
December 2024
Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China. Electronic address:
Purpose: To explore the efficacy of interventional ultrasound treatment for hoarseness caused by nondisconnected recurrent laryngeal nerve injury after thyroidectomy.
Materials And Methods: In this retrospective study, we analysed the clinical data of 21 patients who underwent interventional ultrasound therapy (ultrasound-guided injection of a Diprospan and saline mixture) for postthyroidectomy hoarseness at our hospital between August 1, 2023, and January 31, 2024 (the Diprospan group) and randomly selected 21 patients who did not receive any treatment for postthyroidectomy hoarseness during the same period as the control group. The average vocal cord activity improvement time for the Diprospan group was calculated and compared with that of untreated patients from previous studies.
Chinese guidelines for ultrasound-guided thermal ablation of thyroid nodules (2024 Edition).
Int J Surg
December 2024
Department of Interventional Ultrasound, Chinese PLA General Hospital, Beijing, China.
The Chinese Guidelines for Ultrasound-guided Thermal Ablation of Thyroid Nodules (2024 edition) were jointly initiated by the Ultrasound Committee of Chinese Medical Association, the Interventional Ultrasound Committee of Chinese Association of Ultrasound in Medicine and Engineering, the Ultrasonic Intervention Committee of Chinese Colleges of Interventionalists, the Oncological Intervention Committee of Chinese Research Hospital Association, 37 multidisciplinary experts in interventional ultrasound, ultrasound medicine, endocrinology and thyroid surgery participated in the compilation of this guide, which expanded the depth and breadth of the perspective and enhanced the authority of the guide. Based on the systematic review of literatures related to ultrasound-guided thermal ablation of thyroid nodules and the professional opinions of experts, the guidelines define the indications and contraindications of thermal ablation, including pre-ablation evaluation and preparation, thermal ablation techniques and operational procedures, post-ablation follow-up, therapeutic effect evaluation, complications prevention and treatment, and the writing of medical documents for ablation. According to the Grading of Recommendations Assessment, Development and Evaluation (GRADE), a total of 17 objective and comprehensive recommendations were given.
View Article and Find Full Text PDFExtraction and Analytical Methods for the Characterization of Polyphenols in Marine Microalgae: A Review.
Mar Drugs
November 2024
Department for Life Quality Studies, University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy.
Marine microalgae are emerging as promising sources of polyphenols, renowned for their health-promoting benefits. Recovering polyphenols from microalgae requires suitable treatment and extraction techniques to ensure their release from the biomass and analytical methodologies to assess their efficiency. This review provides a comprehensive comparison of traditional and cutting-edge extraction and analytical procedures applied for polyphenolic characterization in marine microalgae over the past 26 years, with a unique perspective on optimizing their recovery and identification.
View Article and Find Full Text PDFUltrasonication outperforms electroporation for extracellular vesicle cargo depletion.
Extracell Vesicle
December 2024
The Pq Laboratory of BiomeDx/Rx, Department of Biomedical Engineering, Binghamton University, Binghamton, NY, 13902, USA.
Extracellular vesicles (EVs), submicron-sized membranous structures released by cells, serve as vehicles of tissue-specific proteins and nucleic acids, facilitating intercellular communication and playing roles in pathophysiological processes. Leveraging their unique characteristics, EVs have emerged as promising drug delivery nanocarriers. Electroporation (EP) and ultrasonication (US) are among the prevalent techniques used for loading exogenous drugs into EVs owing to their simplicity and efficiency.
View Article and Find Full Text PDFClinical Study on the Treatment of Upper Limb Dysfunction in Stroke Patients Using Ultrasound-Guided Electroacupuncture.
J Mot Behav
December 2024
Department of Vasculocardiology, Chuzhou First People's Hospital, Chuzhou, Anhui Province, China.
This study aimed to compare the effects of electroacupuncture on traditional acupoints and muscle belly of different target muscles against upper limb dysfunction in stroke patients with hemiplegia. A total of thirty-nine stroke patients with subacute hemiplegia were randomly divided into the control group ( = 19) and observation group ( = 20). The control group was treated with physical therapy and normal electroacupuncture, while the observation group was treated with physical therapy and ultrasound-guided electroacupuncture on the muscle belly.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!