The gradient coils of MRI equipment can induce vibrations in implantable medical devices, causing periodic vibrations of implantable medical devices with respect to the surrounding tissue. This not only results in instrument failure but also causes discomfort to the patient. Therefore, studying the vibration characteristics of implantable devices under different scanning sequences and the orientation of the device relative to the magnetic field is crucial for comprehending vibration performance. This study observed the vibration spectra of a full cranial bone-implanted neurostimulator by using laser vibrometry under typical rapid imaging sequences and explored the impact of different magnetic field orientations on vibration. The results demonstrated that the rapid echo sequences induced diverse and rich vibration components, whereas the planar echo sequences caused relatively simple vibrations. Additionally, the strongest vibrations normally occurred in the maximum conductive surface parallel to the phase-coded direction. It revealed the factors influencing the vibrations of skull fixation active implantable devices and provided guidance for enhancing device safety and protecting patient well-being during MR examinations.
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http://dx.doi.org/10.12455/j.issn.1671-7104.240229 | DOI Listing |
Ultrasonics
March 2025
Key Laboratory of Mechanics on Disaster and Environment in Western China, the College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, China. Electronic address:
This study aims to investigate the relationship between the grain size of salicylic acid crystals and the frequency of acoustic emission signalsduring the crystallization of salicylic acid. During the crystallization process of salicylic acid, an acoustic emission system was utilized to monitor the emitted sound signals. Based on the beam vibration theory, a lateral vibration model of the crystals was constructed to study the correlation between acoustic emission signals and crystal grain size.
View Article and Find Full Text PDFMed Eng Phys
March 2025
Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384, PR China; National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin 300384, PR China. Electronic address:
The dynamic response mechanism of osteocytes to whole-body low-amplitude high-frequency vibration (LMHFV) is investigated using numerical simulation. In this study, a finite element model of a single bone lacuna-osteocyte incorporating the cytoskeleton was established. The vibration parameter dependence characteristics (acceleration amplitude (a), frequency (f)) of the dynamic osteocyte response under LMHFV were simulated.
View Article and Find Full Text PDFBiophys J
March 2025
Department of Chemistry, University of Utah, Salt Lake City, Utah.
Vitamin E (VE) has historically been described as an anti-oxidant and its roles in radical species scavenging and nutrition are well studied. VE has been proposed to have secondary roles within the membrane but these roles are not as well characterized, with contradictory results emerging throughout the literature. Due to similar structural motifs, comparisons between VE and cholesterol (CHO), another membrane component, have been commonly made.
View Article and Find Full Text PDFSci Rep
March 2025
School of Mechanical Engineering and Automation, University of Science and Technology Liaoning, Anshan, 114051, China.
In this paper, an innovative axial domain decomposition method, which uniquely integrates axial and circumferential perforation parameters, is developed for semi-analytical modeling of free vibration of a hard-coating cylindrical shell with arbitrary axial and circumferential perforations, based on the Love's first-order shear deformation theory and Rayleigh-Ritz method. The concept of this method is to decompose the shell into two types of domains at the upper and lower axial boundaries of the circular perforations. The generalized semi-analytical formulas of the perforated composite shell can be derived by assembling the separated energy expressions of each domain.
View Article and Find Full Text PDFMicromachines (Basel)
January 2025
School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
In differential MEMS resonant sensors, a pair of resonators are interconnected with other structural components while sharing a common substrate. This leads to mutual coupling of vibration energy between resonators, interfering with their frequency outputs and affecting the sensor's static performance. This paper aims to model and analyze the vibration coupling phenomena in differential common-based MEMS resonators (DCMR).
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