Resonance frequency analysis (RFA) is valuable for assessing implant status. In a previous investigation, acetabular cup fixation was assessed using laser RFA and the pull-down force was predicted in an in vitro setting. While the pull-down force alone is sufficient for initial fixation evaluation, it is desirable to evaluate the bone strength of the foundation for subsequent fixation. Diminished bone quality causes micromotion, migration, and protracted osseointegration, consequently elevating susceptibility to periprosthetic fractures and failure of ingrained trabecular bone. Limited research exists on the evaluation of bone mineral density (BMD) around the cup using RFA. For in vivo application of laser RFA, we implemented the sweep pulse excitation method and engineered an innovative laser RFA device having low laser energy and small dimensions. We focused on a specific frequency range (2500-4500 Hz), where the peak frequency was presumed to be influenced by foundational density. Quantitative computed tomography with a phantom was employed to assess periprosthetic BMD. Correlation between the resonance frequency within the designated range and the density around the cup was evaluated both in the laboratory and in vivo using the novel laser RFA device. The Kruskal-Wallis test showed robust correlations in both experiments (laboratory study: R = 0.728, p < 0.001; in vivo study: R = 0.619, p < 0.001). Our laser RFA system can assess the quality of bone surrounding the cup. Laser RFA holds promise in predicting the risk of loosening and might aid in the decision-making process for additional fixation through screw insertion.

UNASSIGNED: Recent years have seen a rise in the usage of dental implants to restore lost teeth. The stability of a dental implant is the main factor in determining its success. Implant stability is influenced by various factors. Several approaches have been employed clinically to evaluate stability at different time intervals. One non-invasive way to assess implant stability is by resonance frequency analysis. Utilizing the resonance frequency analysis method, this study seeks to understand how implant length and diameter affect primary and secondary stability.
UNASSIGNED: The current prospective study was conducted in the Prosthodontics Department of Institute of Dentistry, CMH Lahore Medical College. The duration of the study was six months. A total of 90 implants of sizes 4.5 x 8.5 mm and 4 x 10mm were placed. Resonance frequency measurements were recorded using Osstell™ AB device for primary stability at implant insertion and at 12 weeks for secondary stability. All the measurements were carried out by only one of the researchers to minimize inter-observer bias.
UNASSIGNED: The average primary stability was 70.33±6.60, and the average secondary stability was 71.43±5.44. The data was stratified for age, gender, and implant site, and the mean primary and secondary stability of both sizes didn\'t show any statistically significant differences.
UNASSIGNED: Without forfeiting implant stability, both implant sizes (4 x 10mm and 4.5 x 8.5mm) can be used interchangeably, depending on available space and anatomical constraints.

Zero-Group-Velocity (ZGV) Lamb waves in elastic plates had been conducted extensive theoretical and experimental researches in the field of ultrasonic nondestructive testing. The ZGV modes in complex structures had been studied theoretically, but less attention had been paid to their experimental investigation. This paper reports the experimental observation of Zero-Group-Velocity Feature Guided Waves (ZGV-FGWs) in a welded joint using the pitch-catch measurement technique with air-coupled ultrasonic transducers. Firstly, for the elastic plate, it is verified that the received time-domain signal using the pitch-catch measurement method with air-coupled ultrasonic transducers is indeed ZGV Lamb waves. Subsequently, we applied the same pitch-catch measurement method with air-coupled ultrasonic transducers to receive time-domain signals at different excitation frequencies in the welded joint. It is observed that the received time-domain signals in the welded joint oscillate for extended periods of time. By performing short-time Fourier transforms on the received time-domain signals, we analyze the frequency content of the received time-domain signals at different excitation carrier frequencies. By analyzing the spectral amplitude variations of these signals at different excitation carrier frequencies, it can be demonstrated that the spectral amplitude corresponding to the resonance frequency is the largest. These findings collectively affirm that the received time-domain signals in the welded joint exhibit ZGV characteristics, identified as ZGV-FGWs. Consequently, from an experimental perspective, the presence of ZGV-FGWs in the welded joint is verified. Moreover, the experimentally determined resonance frequency of ZGV-FGWs concurs with the results obtained through simulation. This study confirms the feasibility of using the pitch-catch measurement method with air-coupled ultrasonic transducers to excite ZGV-FGWs in a welded joint and provides a reference for future experimental investigations of ZGV-FGWs in complex structures.

This article presents a parametrized response model that enhances the limit of detection (LOD) of piezoelectrically driven microcantilever (PD-MC) based gas sensors by accounting for the adsorption-induced variations in elastic properties of the functionalization layer (binder) and the nonlinear motional dynamics of the PD-MC. The developed model is demonstrated for quantifying cadaverine, a volatile biogenic diamine whose concentration is used to assess the freshness of meat. At low concentrations of cadaverine, an increase in the resonance frequency is observed, contrary to the expected reduction due to mass added by adsorption. The study explores the variations in the elastic modulus vis-à-vis the adsorbed mass of cadaverine and derives the resonance frequency to the adsorbed mass response function. We advance a blended technique involving the analysis of atomic force microscopy (AFM) force-distance (f-d) curves and fitting of the quartz crystal microbalance (QCM) impedance response spectrum to deduce the adsorption-induced changes in the viscoelastic properties of the functionalization layer. The findings obtained are subsequently employed in modeling the response function for a structurally nonhomogenous PD-MC, highlighting the significance of the functionalization layer to the global elastic properties. The structural composition of the PD-MC beam adopted herein features a trapezoidal base hosting the actuating piezoelectric stratum and a rectangular free end with a functionalization layer. The Euler-Bernoulli beam theory coupled with Hamilton\'s principle is used to develop the equation of motion, which is subsequently discretized into a set of nonlinear ordinary differential equations via Galerkin expansion, and the solutions to the first fundamental mode of vibration are determined using the method of multiple scales. The obtained solutions provide a basis for deducing the nonlinear response function model to the adsorbed mass. The derived model is validated by recorded resonance frequency changes resulting from exposure to known concentrations of cadaverine. We demonstrate that the increase in resonance frequency for low concentrations of cadaverine is due to the dominance of the variation of the elastic modulus of the functionalization layer originating from the initial binder-analyte interactions over damping due to added mass. It is concluded that the developed nonlinear response function model can reliably be used to quantify the cadaverine concentration at low concentrations with an elevated Limit of Detection.

In our study, we designed and developed a glucose biosensor that operates without a battery or chip. This biosensor utilizes the principles of radio frequency (RF) to operate. For the construction of a glucose-sensitive interdigitated capacitor (IDC), a famous glucose-sensitive substance called phenylboronic acid (PBA) is combined with a polyvinyl chloride (PVC) and n,n-dimethylacetamide (DMAC) solution. According to the theory of radio frequency sensing, the resonance frequency shifts whenever there is a change in the capacitance of the glucose-sensitive IDC. This change is caused by the fluctuations in glucose concentrations. As far as we are aware, this is the first glucose sensor that employs the RF principle to detect changes in glucose solution concentrations using PBA as the principal glucose-sensitive material. The sensor can detect glucose levels with remarkable sensitivity, around 40.89 kHz/decade, and a broad dynamic range covering 10 μM to 1 M. Additionally, the designed biosensor has excellent linearity performance, with a value of around 0.988. The proposed glucose biosensor has several benefits: lightweight, inexpensive, easy to build, and an acceptable selectivity response. Our study concludes by comparing the proposed RF sensor\'s effectiveness to that of existing glucose sensors, which it outperforms.

OBJECTIVE: High-frequency chest wall compression (HFCC) therapy by airway clearance devices (ACDs) acts on the rheological properties of bronchial mucus to assist in clearing pulmonary secretions. Investigating low-frequency vibrations on the human thorax through numerical simulations is critical to ensure consistency and repeatability of studies by reducing extreme variability in body measurements across individuals. This study aims to present the numerical investigation of the harmonic acoustic excitation of ACDs on the human chest as a gentle and effective HFCC therapy.
METHODS: Four software programs were sequentially used to visualize medical images, decrease the number of surfaces, generate and repair meshes, and conduct numerical analysis, respectively. The developed methodology supplied the validation of the effect of HFCC through computed tomography-based finite element analysis (CT-FEM) of a human thorax. To illustrate the vibroacoustic characteristics of the HFCC therapy device, a 146-decibel sound pressure level (dBSPL) was applied on the back-chest surface of the model. Frequency response function (FRF) across 5-100 Hz was analyzed to characterize the behaviour of the human thorax with the state-space model.
RESULTS: We discovered that FRF pertaining to accelerance equals 0.138 m/s2N at the peak frequency of 28 Hz, which is consistent with two independent experimental airway clearance studies reported in the literature. The state-space model assessed two apparent resonance frequencies at 28 Hz and 41 Hz for the human thorax. The total displacement, kinetic energy density, and elastic strain energy density were furthermore quantified at 1 µm, 5.2 µJ/m3, and 140.7 µJ/m3, respectively, at the resonance frequency. In order to deepen our understanding of the impact on internal organs, the model underwent simulations in both the time domain and frequency domain for a comprehensive analysis.
CONCLUSIONS: Overall, the present study enabled determining and validating FRF of the human thorax to roll out the inconsistencies, contributing to the health of individuals with investigating gentle but effective HFCC therapy conditions with ACDs. This innovative finding furthermore provides greater clarity and a tangible understanding of the subject by simulating the responses of CT-FEM of the human thorax and internal organs at resonance.

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Nanoresonators are powerful and versatile tools promising to revolutionize a wide range of technological areas by delivering unparalleled performance in physical, chemical, biological sensing, signal and information processing, quantum computation, etc., via their high-frequency resonant vibration and rich dynamic behavior. Having the ability to tune the resonance frequency and dynamic behavior at the application stage promises further improvement in their effectiveness and enables novel applications. However, achieving significant room-temperature tunability in conventional (monolithically fabricated) nanoresonators is considered challenging. Here we demonstrate ultrawide electrostatic tuning (∼70%) of (initial) resonance-frequency (∼7% V-1) at room temperature in a monolithically fabricated ultrathin Si nanoresonator (width ∼ 40 nm, length ∼ 200 μm) device. Extreme electrostatic tuning of nonlinear behavior is also demonstrated by canceling the cubic-nonlinear coefficient and subsequently flipping its sign. Thus, these results are expected to provide remarkable operational flexibility and new capabilities to microfabricated resonators, which will benefit many technological areas.

BACKGROUND: Biosensors and MEMS have witnessed rapid development and enormous interest over the past decades. Constant advancement in diagnostic, medical, and chemical applications has been demonstrated in several platforms and tools. In this study, the analytical and FEA of the microcantilever used in biomolecular analyses were compared with the experimental analysis results.
METHODS: In this study, MITF antigen, which is a melanoma biomarker, and anti-MITF antibody (D5) were selected as biomolecules. A MEMS-type microcantilever biosensor was designed by functionalizing the AFM cantilever by utilizing the specific interaction dynamics and intermolecular binding ability between both molecules. Surface functionalization of cantilever micro biosensors was performed by using FEA. The stress that will occur as a result of the interactions between the MITF-D5 has been determined from the deviation in the resonant frequency of the cantilever.
RESULTS: It has been found that the simulation results are supported by analytical calculations and experimental results.
CONCLUSIONS: The fact that the results of the simulation study overlap with the experimental and mathematical results allows us to get much cheaper and faster answers compared to expensive and time-consuming experimental approaches.

In this paper, the coupled vibration behavior of cylindrical-conical and cylindrical-exponential ultrasonic concentrators for efficient energy transfer is investigated. A theoretical model is developed to overcome the limitations of traditional one-dimensional theories that neglect the influence of height in the study of cylindrical concentrator vibration. Employing the equivalent elasticity method, the coupled vibration is considered as an interaction between longitudinal and plane radial vibrations. By establishing radial and longitudinal equivalent circuits with their corresponding input impedances, resonance frequency equations and the radial displacement amplification factor are derived. The effects of the radial thickness and the height-to-radius ratio on the characteristic parameters are presented for optimization designs. Numerical simulations are conducted to analyze vibrational modes and validate the theoretical findings. This study enhances the understanding of the vibration mechanism of cylindrical concentrators and provides valuable insights for selecting suitable cross-sections to improve performance and effectiveness in practical applications.