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Laser Resonance Frequency Analysis: A Novel Measurement Approach to Evaluate Acetabular Cup Stability During Surgery
摘要： Artificial joint acetabular cup stability is essential for successful total hip arthroplasty. However, a quantitative evaluation approach for clinical use is lacking. We developed a resonance frequency analysis (RFA) system involving a laser system that is fully contactless. This study aimed to investigate the usefulness of laser RFA for evaluating acetabular cup stability. First, the finite element method was performed to determine the vibration mode for analysis. Second, the acetabular cup was press-fitted into a reamed polyurethane cavity that replicated the human acetabular roof. The implanted acetabular cup was vibrated with pulse laser irradiation and the induced vibration was detected with a laser Doppler vibrometer. The time domain signal from the vibrometer was analyzed by fast Fourier transform to obtain the vibration frequency spectrum. After laser RFA, the pull-down force of the acetabular cup was measured as conventional implant fixation strength. The frequency of the first highest amplitude between 2 kHz and 6 kHz was considered as the resonance peak frequency, and its relationship with the pull-down force was assessed. The peak frequency could predict the pull-down force (R2 = 0.859, p < 0.000). Our findings suggest that laser RFA might be useful to measure acetabular cup stability during surgery.
关键词： implant stability,laser,resonance frequency analysis,total hip arthroplasty,finite element method,acetabular cup
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Research on the resonance frequency reduction of the single fiber scanner
摘要： Single fiber scanner has been applied in many fields, such as minimally invasive surgery, nondestructive testing(NDT), borescopy technology. The resonance frequency of the single fiber cantilever is an important parameter for a scanner. Especially in the application of OCT (Optical Coherence Tomography), a relatively low resonance frequency is required. In this study, we proposed a new method to lower the resonance frequency of the single fiber scanner, other than simply lengthening the fiber. The simulation results agree well with the measured data.
关键词： single fiber scanner,fiber cantilever,resonance frequency
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON) - Lviv, Ukraine (2019.7.2-2019.7.6)] 2019 IEEE 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON) - Study of Perspective of Gaseous Dielectric Parameters Monitoring with Use of Coupled Biconical Resonators
摘要： The advantages of using coupled biconical resonators for monitoring the parameters of gaseous dielectrics are considered in the paper. In this case, one of the resonators is the reference one. Application of coupled biconical resonators makes it possible to detect deviations of the dielectric constant and loss tangent of the test medium with values of the order of 10-4 and 10-5 correspondingly.
关键词： coupled resonators,Q-factor,biconical resonator,resonance frequency,the complex dielectric constant
更新于2025-09-11 14:15:04
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A highly accurate measurement of resonator <i>Q</i> -factor and resonance frequency
摘要： The microwave cavity perturbation method is often used to determine material parameters (electric permittivity and magnetic permeability) at high frequencies, and it relies on the measurement of the resonator parameters. We present a method to determine the Q-factor and resonance frequency of microwave resonators which is conceptually simple but provides a sensitivity for these parameters which overcomes those of existing methods by an order of magnitude. The microwave resonator is placed in a feedback resonator setup, where the output of an amplifier is connected to its own input with the resonator as a bandpass filter. After reaching steady-state oscillation, the feedback circuit is disrupted by a fast microwave switch, and the transient signal, which emanates from the resonator, is detected using down-conversion. The Fourier transform of the resulting time-dependent signal yields directly the resonance profile of the resonator. Albeit the method being highly accurate, this comes with a conceptual simplicity, ease of implementation, and lower circuit cost. We compare existing methods for this type of measurement to explain the sensitivity of the present technique, and we also make a prediction for the ultimate accuracy for the resonator Q and f0 determination.
关键词： down-conversion,microwave cavity perturbation,feedback oscillator,Q-factor,resonance frequency
更新于2025-09-10 09:29:36
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Frequency-Tunable Power Divider Based on Frequency Sampling Method
摘要： A novel frequency-tunable power divider based on frequency sampling method is designed in this paper. The frequency-tunable structure located on the input-port of the is different from the conventional power divider, which frequency-tunable method. The frequency-tunable function of the frequency-tunable structure depends on the slot-line resonator. The resonant frequency of the slot-line resonator can be tuned by changing the voltage of the parallel varactor. The frequency-tunable power divider has the features of simple structure and easy-to-realization. Only one varactor is used for the tunable frequency. The simulated results show that the operation frequency of the power divider can be tuned between 0.87GHz and 1.45GHz with the return loss and the isolation greater than 15dB. The output-port’s amplitude unbalance is less than 0.05dB and the phase unbalance is less than 0.5degree.
关键词： frequency-tunable,resonance,frequency sampling method,power divider
更新于2025-09-09 09:28:46
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Characterization of core–shell nanostructure consisting Si–Au–SiO2 based on manipulation of optical properties
摘要： In this article, we investigated some physical characteristics of core–shell nanostructure in optical regime and perturbation has been also introduced as an effective method in shaping of optical properties. The proposed nanostructures are composed of the selected materials as: Silicon, Silicon Dioxide and Gold. At first, the extinction cross section spectra are calculated for multilayer core–shell nanostructures in optical range and the configuration effect of the constructed materials in a multilayer nanostructure are investigated for determination of Plasmon range. Then, the new structures of core–shell nanoparticles (gold–silicon) are presented, which have an amount of impurity particle in their shells as perturbation and also their extinction cross section spectra are calculated. The obtained results in this article give a proper approach about perturbation effect in broadening, sharpening and shifting of optical response which are decisive factors especially nano-network systems. Indeed, it has been proposed that the impurity particles in the shells can be a mechanism for tuning of optical characteristics of the presented nanoparticles in practical fields and also creation of local oscillations as plasmonic resonances in a considered optical range. Besides, redshift in extinction cross section can be also created by particle perturbation. At the end, the effective permittivity of the perturbed core-shells are extracted. The optional frequency range is selected between 300 and 900 (THz).
关键词： Effective permittivity,Perturbation,Nanoparticle impurity,Extinction cross section,Core–shell nanostructure,Plasmonic resonance frequency
更新于2025-09-09 09:28:46
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Characterization of ultrafast plasmon dynamics in individual gold bowtie by time-resolved photoemission electron microscopy
摘要： We report on the investigation of ultrafast dynamics of the plasmonic field in individual gold bowtie nanostructure by combining interferometric time-resolved photoemission electron microscopy with a damped harmonic oscillator model. We experimentally obtain different plasmon dephasing times in the tips of the bowtie nanostructure. In the meantime, we demonstrate that the experimental time-resolved photoemission signal can be used to directly compare resonance frequency and dephasing time of different hot spots. In addition, we find that the plasmon field, which is extracted from the photoemission signal, initially oscillates at the laser field frequency, and finally develops into its eigenfrequency after experiencing a few periods of frequency fluctuation due to the competition between forced and autonomous oscillation of the plasmons.
关键词： ultrafast plasmon dynamics,gold bowtie,resonance frequency,plasmon dephasing times,time-resolved photoemission electron microscopy
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP) - Hiroshima (2018.5.27-2018.6.1)] 2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP) - Piezoelectric Resonating Force Sensor in the Second Vibration Mode
摘要： A resonating force sensor is studied, which is composed of a metal bridge coated with a piezoelectric ?lm for force detection. It is thought to operate the sensor at the second ?exural vibration mode having one node at the center of the bridge. Resonance frequency and piezoelectric coupling are investigated in the frame of an analytical model, and compared with ?nite element analysis (FEA) in a desired force range. The resonance frequency-force relation derived from the analytical model is close the the FEA result in the force range. The coupling factor-force relation from the analytical model agrees with the one from FEA in the small force region, but it shows lower coupling than the FEA result in the large force region.
关键词： Resonance sensor,Electromechanical coupling,Piezoelectric sensor,Force sensor,Resonance frequency,Second mode
更新于2025-09-04 15:30:14