Evaluation of a vibration modeling technique for the in-vitro measurement of dental implant stability

The Advanced System for Implant Stability Testing (ASIST) is a device currently being developed to noninvasively measure implant stability by estimating the mechanical stiffness of the bone-implant interface, which is reported as the ASIST Stability Coefficient (ASC). This study's purpose was to determine whether changes in density, bonding, and drilling technique affect the measured vibration of a dental implant, and whether they can be quantified as a change in the estimated BII stiffness. Stability was also measured using RFA, insertion torque (IT) and the pullout test. Bone-level tapered implants (4.1 mm diameter, 10 mm length) were inserted in polyurethane foam as an artificial bone substitute. Samples were prepared using different bone densities (20, 30, 40 PCF), drilling sequences, and superglue to simulate a bonded implant. Measurements were compared across groups at a significance level of 0.05. The ASC was able to indicate changes in each factor as a change in the interfacial stiffness. IT and pullout force values also showed comparable increases. Furthermore, the relative difference in ISQ values between experimental groups was considerably smaller than the ASC. While future work should be done using biological bone and in-vivo systems, the results of this in-vitro study suggest that modelling of the implant system with a vibration-based approach may provide a noninvasive method of assessing the mechanical stability of the implant.

A nasal airflow oscillation device targeting nasal congestion: a preliminary report

PURPOSE

Upper respiratory tract complaints are common in the general population. A safe, non-pharmacologic treatment would be an attractive option for many patients either as an alternative to existing therapies, or as a complementary therapy. This study assessed the acceptability, safety and possible efficacy of a nasal airflow oscillation device in a group of people suffering chronic nasal congestion.

METHODS

Subjects with a known history of nasal congestion, but without fixed anatomical obstruction, participated in a prospective clinical study. Efficacy was assessed using peak nasal inspiratory flow (NPIF) and a 10-point visual analogue scale (VAS) administered before and after the oscillation device had been worn for twenty minutes.

RESULTS

Twenty-one subjects (mean age 37 years; 43% female) were enrolled in the study. After treatment with the small nasal airflow oscillation device for twenty minutes, average NPIF increased significantly from 84.8 L/minute to 99.0 L/minute (p < 0.05). There was a corresponding significant reduction in the VAS score for nasal congestion (p < 0.05). Similar significant improvements were also seen for the immediate sensation of nasal drainage, sinonasal pressure and overall sinonasal symptoms (p < 0.05). There was no change in the sense of smell (p = 0.37). Subjects rated ease of use highly; average = 9.1 (Range 7-10).

CONCLUSION

Treatment of nasal congestion with the nasal airflow oscillation device was found to result in significant improvement in NPIF after twenty minutes of use. Initial patient-reported outcomes improved significantly, and the treatment was safe and highly acceptable.

TRIAL REGISTRATION

Public clinical trial registration: Universal Trial Number (U1111-1259-0704). Australian New Zealand clinical trials registration: ACTRN12623001307695.

Effect of sensor location for modifying center of pressure during gait using haptic feedback in people with chronic ankle instability

BACKGROUND

Gait retraining using haptic biofeedback medially shifts the center of pressure (COP) while walking in orthopedic populations. However, the ideal sensor location needed to effectively shift COP medially has not been identified in people with chronic ankle instability (CAI).

RESEARCH QUESTIONS

Can a heel sensor location feasibly be employed in people with CAI without negatively altering kinematics? Does a heel sensor placement relative to the 5th metatarsal head (5MH) impact COP location while walking in people with CAI?

METHODS

In this exploratory crossover study, 10 participants with CAI walked on a treadmill with vibration feedback for 10 minutes with a plantar pressure sensor under the heel and 5MH. Separate 2×2 repeated measures analyses of covariances (rmANCOVAs) were used to compare the averaged COP location and 3-D lower extremity kinematics from the first 10% of stance before and after training and between sensor locations. Baseline measures served as covariates to adjust for baseline differences.

RESULTS

Feedback triggered by a heel sensor resulted in 40% of participants avoiding a heel strike. There were no significant main effects or interactions between time and sensor location on COP location when controlling for baseline COP (p>0.05). However, with the 5MH placement, participants displayed less ankle internal rotation(IR) (5MH/Heel: -4.12±0.00º/ -6.43±0.62º), less forefoot abduction (-4.29±0.00º/ -5.14±1.01º), more knee flexion (3.40±0.32º/ 0.14±0.57º), less knee external rotation (-10.95±0.00º/-11.24±1.48º), less hip extension (-0.20±0.00º/-1.42±1.05º), and less hip external rotation (3.12±0.00º/3.75±1.98º).

SIGNIFICANCE

A 5MH location may be more feasible based on difficulties maintaining heel strike when the sensor was under the heel. While no sensor location was statistically better at changing the COP, the 5MH location decreased proximal transverse plane motions making participants' gait more like controls. Individual response variations support comprehensive lower extremity assessments and the need to identify responder profiles using sensory feedback in people with CAI.

What are the temporal and physical characteristics of locally applied vibration that modulate balance in older adults? - A systematic review of the literature

BACKGROUND

Compromised balance is known to contribute to falls, which are associated with increased morbidity and mortality for older adults. Evidence suggests that the application of local vibration to the lower limbs of older adults has the potential to modulate balance.

RESEARCH QUESTION

To identify the temporal and mechanical parameters of vibration applied locally to the lower limbs of older adults that modulate measures of balance, and to define the short- and long-term effects of vibration on balance in this population.

METHODS

The PRISMA 2020 guidelines were used to conduct a systematic search including the PUBMED, EMBASE, and Scopus databases to identify peer-reviewed literature where vibration was applied to the lower limbs of older adults to modulate balance. Data was extracted using a study-specific data extraction form and risk of bias assessed. Where possible, effect sizes were calculated.

RESULTS

Of 7777 records screened, ten randomised controlled trials and 43 prospective laboratory-based studies met the inclusion criteria. Vibration frequencies ranged from 1 to 272 Hz, most studies (n=41) used ≤100 Hz. Amplitude ranged from 0.2 to 3.0 mm, most studies (n=28) used ≤1 mm. Effects of short-term vibration (applied for seconds to hours) were measured during and/or immediately after application. Short-term suprathreshold perceived muscle/tendon vibration had a 'large' destabilising effect size on balance in healthy older adults, but little or no effect on older fallers. Short-term subthreshold vibration to the soles of the feet had a 'small' stabilising effect size. Suprathreshold muscle, tendon or sole vibration applied for 10-30 min over days to weeks improved balance measures, but most (8 of 10) had increased risk of bias.

SIGNIFICANCE

The heterogeneity of methodology, populations, and vibration and balance parameters precluded conclusions about the relative effects of lower limb vibration in older adults. However, these results suggest that the application of local vibration to the lower limbs of older adults can modulate balance in the short- and long-term.

Desmin gene expression is not ubiquitous in all upper airway myofibers and the pattern differs between healthy and sleep apnea subjects

BACKGROUND

Desmin is a major cytoskeletal protein considered ubiquitous in mature muscle fibers. However, we earlier reported that a subgroup of muscle fibers in the soft palate of healthy subjects and obstructive sleep apnea patients (OSA) lacked immunoexpression for desmin. This raised the question of whether these fibers also lack messenger ribonucleic acid (mRNA) for desmin and can be considered a novel fiber phenotype. Moreover, some fibers in the OSA patients had an abnormal distribution and aggregates of desmin. Thus, the aim of the study was to investigate if these desmin protein abnormalities are also reflected in the expression of desmin mRNA in an upper airway muscle of healthy subjects and OSA patients.

METHODS

Muscle biopsies from the musculus uvulae in the soft palate were obtained from ten healthy male subjects and six male patients with OSA. Overnight sleep apnea registrations were done for all participants. Immunohistochemistry, in-situ hybridization, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) techniques were used to evaluate the presence of desmin protein and its mRNA.

RESULTS

Our findings demonstrated that a group of muscle fibers lacked expression for desmin mRNA and desmin protein in healthy individuals and OSA patients (12.0 ± 5.6% vs. 23.1 ± 10.8%, p = 0.03). A subpopulation of these fibers displayed a weak subsarcolemmal rim of desmin accompanied by a few scattered mRNA dots in the cytoplasm. The muscles of OSA patients also differed from healthy subjects by exhibiting muscle fibers with reorganized or accumulated aggregates of desmin protein (14.5 ± 6.5%). In these abnormal fibers, the density of mRNA was generally low or concentrated in specific regions. The overall quantification of desmin mRNA by RT-qPCR was significantly upregulated in OSA patients compared to healthy subjects (p = 0.01).

CONCLUSIONS

Our study shows evidence that muscle fibers in the human soft palate lack both mRNA and protein for desmin. This indicates a novel cytoskeletal structure and challenges the ubiquity of desmin in muscle fibers. Moreover, the observation of reorganized or accumulated aggregates of desmin mRNA and desmin protein in OSA patients suggests a disturbance in the transcription and translation process in the fibers of the patients.

Vibration spectra of DNA and RNA segments

The dispersion curves and density of states are used to analyze the vibrational characteristics of DNA and RNA segments. This is done using a harmonic Hamiltonian and the Green's function technique. Two configurations of DNA and RNA, finite and cyclic, have been investigated and compared to their infinite counterparts. For the DNA molecule, three models, including a fishbone model, a ldder model, and a fishbone ladder model, have been employed, while the RNA molecule has been represented using a half fishbone model. To enhance the realism of DNA and RNA simulations, the unit cells within each infinite system as well as the length of the finite and cyclic cases are gradually enlarged. The connections between the sub-sites have been modeled using linear springs, where the stiffness of the vertical springs exhibits random variations throughout the length of the DNA and RNA models. Shorter DNA and RNA segments exhibit additional peaks in their density of states, resulting in more bands in dispersion curves. This indicates that as the number of building blocks grows in these segments, their curves resemble those of infinite systems. These findings have practical implications for studying the vibration characteristics of similar macro-systems.

Numerical simulation of shoegear-rail coupling vibration under different initial contact forces

As cities have grown, conductor rail power supplies have been widely used in the field of urban rail transit. In order to improve the running performance of trains and reduce the occurrence of accidents, it is necessary to understand the vibration of shoegear-rail system under different initial contact forces and explore the dynamic performance of shoegear-rail system. Therefore, according to the structure of shoegear-rail system, a coupling model of shoegear-rail system is established in this paper. On the basis of the model, the numerical simulation of the shoegear-rail system under different initial contact forces is carried out, and finally the vibration data of the shoegear-rail system under different initial contact forces are obtained. The results show that with the increase of initial contact force in the range of 70-160 N, the vibration amplitude of the electric shoegear and the fluctuation amplitude of the contact force increase, but the maximum absolute shear force value of the conductor rail decreases. It indicates that the lower initial contact force, the better the performance of shoegear-rail system.

Experimental study on shearer traction vibration considering attitude disturbances

Due to the influence of structural clearances, the shearer's oscillates and jumps concerning the scraper are frequent, which induces the collision and vibration impact of the traction components and exacerbates the traction failure of the shearer. Therefore, to explore the correlation between attitude disturbance and traction vibration, an experiment on the traction vibration is carried out, the spatial swaying of the shearer and vibration differences between two traction components are obtained, the influence of the lifting angle of the rocker arm is discussed, and the influence mechanism of the shearer attitude disturbance on traction vibration is elucidated. The results indicate that the rolling swing intensity of the shearer is the highest while the yawing swing intensity is the lowest, and the pitch swing intensity increases with the increase of the lifting angle of the rocker arm. Besides, the vibration impact indices of the two walking mechanisms have a competitive relationship of one decreasing but the other increasing, which can be used as a reference signal to judge the rolling swing and load-sharing performance of the traction part. Moreover, with the swing attitude, the competitive relationship of the average of vibration peaks is shown in the two support shoes, and it can be used as a reference signal to judge the pitching swing and the load-sharing performance of the traction part. This result reveals the impact mechanism of attitude disturbances on traction vibration and proposes a signal monitoring approach for judging the traction attitude disturbance and load-sharing performance, providing a reference for reducing traction faults.

Enhanced interfacial boiling of impacting droplets upon vibratory surfaces

HYPOTHESIS

Despite the flourishing studies of droplet interfacial boiling, the boiling upon vibratory surfaces, which may cause vigorous liquid-vapor-solid interactions, has rarely been investigated. Enhanced boiling normally can be gained from rapid removal of vapor and disturbance of liquid-vapor interface. We hypothesize that the vibratory surfaces enhance both effects with new intriguing phenomena and thus, attain an enhanced boiling heat transfer.

EXPERIMENTS

We experimentally investigated the impacting fluid dynamics and coupled heat transfer patterns of multiple droplets and a single droplet impinging on still and vibratory surfaces of various materials and different wettability.

FINDINGS

The boiling under vibratory surfaces with increased vibration velocity amplitude and enhanced wettability can be enhanced by 80% in heat transfer coefficient and Nusselt number, which is attributed to several reasons: shortened bubble lifespan, thinner and smaller bubbles, and enhanced disturbances in liquid-vapor interfaces. The vibration also delays the Leidenfrost point when the droplet impacts a descending surface, which shows that the droplet impact moment (vibration phase angle) is particularly crucial. The descending surface releases the generated vapor actively and facilitates liquid-solid contact, thereby delaying the Leidenfrost. From fundamentals to application, this article strengthens our understanding of vibrated interfacial boiling in scenarios closer to multiple natural processes and practical industries.

Application of analysis of variance to determine important features of signals for diagnostic classifiers of displacement pumps

This paper presents the use of one-way analysis of variance ANOVA as an effective tool for ranking the features calculated from diagnostic signals and evaluates their impact on the accuracy of the machine learning system's classification of displacement pump wear.The first part includes a review of contemporary diagnostic systems and a description of typical damage of multi-piston displacement pumps and Its causes. The work also contains description of a diagnostic experiment which was conducted in order to obtain the matrix of vibration signals and the matrix of pressures measured at selected locations on the pump housing and at the pump pressure line. The measured signals were subjected to time-frequency analysis. The features of signals calculated in the time and frequency domains were ranked using the ANOVA. The next step involved the use the available classifiers in pump wear evaluation, conducting tests and assessing their effectiveness in terms of the ranking of features and the origin of diagnostic signals.

Comparative study of permeation effects between vibrating microneedle and low-frequency sonophoresis systems

Microneedle transdermal administration and low-frequency ultrasound represent two important physical penetration-promoting methods for enhancing drug penetration. This article aims to investigate and compare the effects of drug penetration enhancement through transdermal administration using vibrating microneedles versus low-frequency sonophoresis. In Vitro permeation studies were conducted using Valia-Chien double chamber diffusion cells to evaluate the transdermal delivery of tetramethylpyrazine hydrochloride (TMPH). The TMPH concentration in the receiving compartment was determined using high-performance liquid chromatography (HPLC). Several combinations of microneedles and ultrasound settings were investigated, including different needle heights, vibration frequencies, exposure times, and assorted distances of ultrasound horn and skin. The results revealed the vibrating microneedle system as the most efficacious treatment to increase the TMPH permeability into the rat skin. The combination of a larger needle, higher frequency, and a 3-min exposure led to a 41.92-fold increase in cumulative permeability compared to the control group. The ultrasound treatment exhibited a moderate enhancement effect on TMPH skin penetration. Using a horn-to-skin distance of 3 mm and a 3-min exposure resulted in a 4.34-fold increase in TMPH cumulative permeation compared to the control group. It could be concluded that while both the vibrating microneedle and the low-frequency ultrasound systems act as penetration enhancers for promoting the TMPH permeation through the skin, the vibrating microneedle system notably demonstrates a more effective penetration-promoting effect.

Study on motion behaviour of coal water slurry particles under vibration conditions

This study uses computational fluid dynamics (CFD) to simulate the motion behavior of coal-water slurry (CWS) particles under vibration conditions. Results show that without vibration, the coal particles settle to the bottom of the container due to gravity, forming distinct regions of low, transition, and high concentration. Under low vibration intensity, the slight energy activates particle motion and promotes settlement. Under high vibration intensity, violent reciprocating motion causes severe shaking and uncertainty, resulting in non-uniform particle distribution and back mixing. Particle velocity distribution is significantly influenced by vibration, with higher frequencies and amplitudes resulting in greater velocities. Additionally, particle pseudo-temperature is higher in the near-wall area due to collisions with particles and wall surfaces. Low frequency and amplitude promote particle settlement, increasing compactness in the bottom area and reducing concentration in the top area. The findings provide valuable insights into CWS behavior under vibration conditions, which can be used to optimize the design and operation of CWS handling and transportation systems.

Effect of vibration of the vortex mixer on the red blood cells

PURPOSES

Red blood cells (RBCs) are often subject to vibration during processing, transfusion, and transport. Further research is necessary to understand the effects of vibration on human RBCs and to reduce experimental deviations caused by device vibration.

METHODS

Flow cytometry was used in this study to observe the cytokine expression of IgG and IgA and deformation of human red blood cells affected by the vibration of a vortex mixer with varying frequency (750 rpm and 1500 rpm), duration (5 min and 10 min), and container volume (96 well plate and 48 well plate).

RESULTS

The size of RBCs in duration of 10 min is obviously smaller than the duration of 5 min. The 10-minute duration led to visibly smaller RBC sizes compared to the 5-minute duration. There was little effect on the size of RBCs in the 10-minute groups from differences in frequency and container volume. However, decreased RBC size can be observed in the 5-minute groups, where frequency is increased or container volume is decreased. Echinocytes were present in photomicrographs of all 10-minute groups, but microstructure of the RBCs was not impacted by vortex mixer vibration. The elevated frequency or reduced container volume results in an increased cytokine expression of IgG within the 5-minute groupings.

CONCLUSION

It can be inferred that vibration must not be overlooked due to its potential impact on the shape and cytokine expression of RBCs. Hence, the inclusion of vibration must be taken into consideration in experiments and devices pertaining to RBCs.

Do soleus responses to transcutaneous spinal cord stimulation show similar changes to H-reflex in response to Achilles tendon vibration?

INTRODUCTION/PURPOSE

Recently, the use of transcutaneous spinal cord stimulation (TSCS) has been proposed as a viable alternative to the H-reflex. The aim of the current study was to investigate to what extent the two modes of spinal cord excitability investigation would be similarly sensitive to the well-known vibration-induced depression.

METHODS

Fourteen healthy participants (8 men and 6 women; age: 26.7 ± 4.8 years) were engaged in the study. The right soleus H-reflex and TSCS responses were recorded at baseline (PRE), during right Achilles tendon vibration (VIB) and following 20 min of vibration exposure (POST-VIB). Care was taken to match H-reflex and TSCS responses amplitude at PRE and to maintain effective stimulus intensities constant throughout time points.

RESULTS

The statistical analysis showed a significant effect of time for the H-reflex, with VIB (13 ± 5% of maximal M-wave (Mmax) and POST-VIB (36 ± 4% of Mmax) values being lower than PRE-values (48 ± 6% of Mmax). Similarly, TSCS responses changed over time, VIB (9 ± 5% of Mmax) and POST-VIB (27 ± 5% of Mmax) values being lower than PRE-values (46 ± 6% of Mmax). Pearson correlation analyses revealed positive correlation between H-reflex and TSCS responses PRE-to-VIB changes, but not for PRE- to POST-VIB changes.

CONCLUSION

While the sensitivity of TSCS seems to be similar to the gold standard H-reflex to highlight the vibratory paradox, both responses showed different sensitivity to the effects of prolonged vibration, suggesting slightly different pathways may actually contribute to evoked responses of both stimulation modalities.

[Discussion on the status quo and problems of health risk management of hand-transmitted vibration in the workplace]

The risk management in workplace is an important measure to effectively prevent and control the harm of hand-transmitted vibration. Based on the relevant developments at home and abroad, this paper expounds the risk of manual vibration operation in workplace by taking contact assessment and hazard assessment as an example. On this basis, the limit management and hierarchical management related to risk management are discussed, and the existing problems are analyzed.

The dropper stress characteristics under different moving load speeds for a high-speed railway

Dropper failure seriously threatens the operation safety of a high-speed railway. In this work, for a simple chain suspension catenary, one span with five droppers is performed to establish a model and thus the effects of the moving load speed on dropper stress are investigated. First, the partial differential vibration equation of dropper is obtained through the mechanical analysis and converted into the finite difference equation. Then, we consider contact line as a beam element to obtain its motion equation. Furthermore, the boundary and initial conditions of five droppers are determined. Finally, the stresses of five droppers are numerically calculated and the effects of the moving load speed on dropper stress are investigated by writing a MATLAB code. The results suggest that the dropper location significantly affects its stress. Compared with other droppers, droppers II and IV have much more severe vibration amplitudes. Different moving load speeds could cause different stress change of each dropper. With the increasing speed, dropper experiences longer bending compression stage and the bending amplitude increases. The impact of the moving load speed on dropper stress is significant.

A finite element method study of the effect of vibration on the dynamic biomechanical response of the lumbar spine

BACKGROUND

Studies focusing on lumbar spine biomechanics are very limited, and the mechanism of the effect of vibration on lumbar spine biodynamics is unclear. To provide guidance and reference for lumbar spine biodynamics research and vibration safety assessment, this study aims to investigate the effects of different vibrations on lumbar spine biodynamics.

METHODS

A validated finite element model of the lumbosacral spine was utilized. The model incorporated a 40 kg mass on the upper side and a 400 N follower preload. As a comparison, another model without a coupled mass was also employed. A sinusoidal acceleration with an amplitude of 1 m/s2 and a frequency of 5 Hz was applied to the upper and lower sides of the model respectively.

FINDINGS

When the coupled mass point is not introduced: in the case of upper-side excitation, the lumbar spine shows a significantly larger response in the x-direction than in the z-direction, while in the case of lower-side excitation, the lumbar spine experiences rigid body displacement in the z-direction without any movement, deformation, rotation, or stress changes in the x-direction. When the coupled mass point is introduced: both upper and lower-side excitations result in significant differences in z-directional displacement, with relatively small differences in vertebral rotation angle, disc deformation, and stress. Under upper excitation, low-frequency oscillations occur in the x-direction. In both types of excitations, the anterior-posterior deformation of the L2-L3 and L4-L5 intervertebral discs is greater than the vertical deformation. The peak (maximum) disc stress exceeds the average stress and stress amplitude across the entire disc. Regardless of the excitation type, the stress distribution within the disc at the moment of peak displacement remains nearly identical, with the maximum stress consistently localized on the anterior side of the L4-L5 disc.

INTERPRETATION

Accurately simulating lumbar spine biodynamics requires the inclusion of the upper body mass in the lumbosacral spine model. The physiological curvature of the lumbar spine could escalate the risk of lumbar spine vibration injuries. It is more instructive to apply local high stress in the disc as a lumbar spine vibration safety evaluation parameter.

Hilbert transform for covariance analysis of periodically nonstationary random signals with high-frequency modulation

We discuss the use of the Hilbert transform for the analysis of periodically non-stationary random signals (PNRSs), whose carrier harmonics are modulated by jointly stationary high-frequency narrow-band random processes. PNRS of this type are suitable models for numerous natural and man-made phenomena, including the vibration of a damaged mechanism. We show that the auto-covariance function of the signal and its Hilbert transform are the same, and that their cross-covariance functions differ only in their sign, meaning that the sum of squares of the signal and its Hilbert transform cannot be considered a 'squared envelope' and no new information is contained compared with the variance of the raw signal. A representation of the signal in the form of a superposition of high-frequency components is obtained and it is shown that these components are jointly periodically non-stationary random processes. The properties of the band-pass filtered signals are examined, and it is shown that band-pass filtering can reduce both the number of signal variance cyclic harmonics and their amplitudes. We show that it is possible to extract the quadratures of narrow-band high-frequency modulation processes using the Hilbert transform. The results obtained here theoretically substantiate the use of the Hilbert transform for the analysis of high-frequency modulation which occurs when a fault appears. They offer a new way to consider the traditional approach to vibration diagnosis. A processing technique that can be considered an alternative to envelope analysis is described, and its use in the analysis of a vibration signal is discussed.

Effect of Whole-Body Vibration on Balance or Proprioception in Nonspecific Chronic Low Back Pain: A Systematic Review

Objective

This systematic review aimed to investigate the effect of whole-body vibration (WBV) on balance or proprioception for patients with nonspecific chronic low back pain (NSCLBP).

Methods

A comprehensive search was conducted using 5 databases-PubMed, Web of Science, Cochrane Library, Science Direct, and Physiotherapy Evidence Database-from inception to January 2022. Randomized clinical trials that examined the efficacy of WBV on balance or proprioception in patients with NSCLBP were incorporated. The methodological quality of each included study was assessed using the Physiotherapy Evidence Database scale.

Results

Our search strategy yielded 5309 articles, of which 7 published randomized clinical trials (313 patients) met the inclusion criteria. Three of the 4 included studies that investigated balance reported significant improvements after WBV, of which 2 were of high methodological quality. The remaining 3 studies investigating proprioception also showed significant improvements after WBV intervention.

Conclusion

Although some studies seem to provide promising results regarding the efficacy of WBV or WBV combined with exercise in improving balance and proprioception in patients with NSCLBP, at present, no definite conclusions can be drawn due to article heterogeneity and lack of clinical trials.

Effect of Vibration and Tilting Mechanical Loading Device on Parthenogenetic Embryos Development of Mice Immature Oocytes

The growth and development of early mammalian embryos mainly take place in the fallopian tube, which not only provides nutrients for embryonic growth and development but also offers suitable mechanical conditions. The embryo culture system established in assisted reproductive technology mainly simulates the environment in which oocytes and embryos grow and develop in vivo. However, current in vitro embryo culture is mainly static and cannot completely mimic the mechanical environment in which embryos grow and develop in vivo. Therefore, to more accurately simulate the mechanical environment of embryos in the fallopian tube, we have developed a dynamic culture device to investigate the effects of mechanical stimulation on the in vitro maturation of immature oocytes and their parthenogenetic developmental potential. Immature mice oocytes were subjected to in vitro maturation by static culture and vibration (3 Hz, 6 Hz) with tilting for 15∼16 hours. The maturation of oocytes was observed after the culture period. The mature oocytes were activated by parthenogenesis and the rate of embryo compaction and formation of parthenogenetic blastocysts was analyzed. The results showed that using 3 Hz vibration and tilting can significantly improve the parthenogenetic development potential of immature mice oocytes.

Investigating gait-responsive somatosensory cueing from a wearable device to improve walking in Parkinson's disease

Freezing-of-gait (FOG) and impaired walking are common features of Parkinson's disease (PD). Provision of external stimuli (cueing) can improve gait, however, many cueing methods are simplistic, increase task loading or have limited utility in a real-world setting. Closed-loop (automated) somatosensory cueing systems have the potential to deliver personalised, discrete cues at the appropriate time, without requiring user input. Further development of cue delivery methods and FOG-detection are required to achieve this. In this feasibility study, we aimed to test if FOG-initiated vibration cues applied to the lower-leg via wearable devices can improve gait in PD, and to develop real-time FOG-detection algorithms. 17 participants with Parkinson's disease and daily FOG were recruited. During 1 h study sessions, participants undertook 4 complex walking circuits, each with a different intervention: continuous rhythmic vibration cueing (CC), responsive cueing (RC; cues initiated by the research team in response to FOG), device worn with no cueing (NC), or no device (ND). Study sessions were grouped into 3 stages/blocks (A-C), separated by a gap of several weeks, enabling improvements to circuit design and the cueing device to be implemented. Video and onboard inertial measurement unit (IMU) data were analyzed for FOG events and gait metrics. RC significantly improved circuit completion times demonstrating improved overall performance across a range of walking activities. Step frequency was significantly enhanced by RC during stages B and C. During stage C, > 10 FOG events were recorded in 45% of participants without cueing (NC), which was significantly reduced by RC. A machine learning framework achieved 83% sensitivity and 80% specificity for FOG detection using IMU data. Together, these data support the feasibility of closed-loop cueing approaches coupling real-time FOG detection with responsive somatosensory lower-leg cueing to improve gait in PD.

Enhanced electrochemical performance of li-ion battery via ultrasonic-assisted inorganic-rich and thin SEI layer

Lithium-ion batteries (LIBs) stand as a compelling solution to energy source transition in various applications such as the vehicle industry due to their energy and power density. However, the impact of mechanical factors on them remains understudied. Of particular interest is the effect of vibration, an inherent characteristic of vehicles, on battery performance. Ultrasound has been reported to improve mass transfer and surface cleaning, yet its effects on LIBs are still not thoroughly investigated. This study investigates the influence of ultrasound on the solid electrolyte interphase (SEI) layer, resulting in a thin, inorganic-rich layer. The induced SEI layer alteration improves charge transfer, showing enhanced kinetics. We also reveal that ultrasound application enhances cycling stability, maintains discharge capacity at high charging rates, and facilitates inorganic-rich SEI layer creation. This novel combination of ultrasound and LIBs presents a promising pathway for achieving high-performance batteries.

Experimental and analytical investigation on forced and free vibration of sandwich structures with reinforced composite faces in an acidic environment

The main objective of this study is to investigate the impact of nanoparticles as reinforcement material on the vibrational behavior of sandwich structures in an acidic medium. The glass fiber reinforced polymer (GFRP) faces were fabricated with and without the addition of 3 wt% nanoclay and nanosilica to determine the mechanical behaviors of the GFRP faces in the presence of an acidic medium. The obtained results showed adding 3 wt% of nanoclay caused better durability and less mass variation of composite specimens in sulfuric acid. The "Coefficient of acidic immersion expansion" (β a c i d ) is determined by measuring the length and mass variation of GFRP specimens in the immersion, and applied to low order piecewise shear deformation theory (LOPSDT) for the first time; Also the frequency results of LOPSDT have been shown good agreement in validation with the ANSYS numerical solution. It is shown that acidic environment reduces the frequency of the first mode of sandwich plates with reinforced face by 3 wt% nanosilica, and nanoclay has increased by 6.81 % and 4.66 %, respectively. This study indicates after one month of immersion, the natural frequency of the sandwich with pure, and 3 wt% nanoclay reduces about 1 %, and the natural frequency of the sandwich with the faces reinforced with 3 wt% nanosilica reduces by more than 3 %; Moreover, the frequency of forced vibrations, caused by acidic immersion expansion, was improved significantly by 10.04 % and 6.54 % in the first mode by incorporating 3 wt% of nanoclay, and nanosilica into the faces of the sandwich in one month of immersion compared to the sandwich with pure faces.

The effect of local vibration applied to the forearm extensor muscles on hand function and muscle activation in stroke patients: a randomized controlled study

OBJECTIVE

This study aims to reveal the effect of low-frequency local vibration applied to the forearm extensor muscles on stroke patients' muscle activation and hand functions.

METHODS

Twenty-four stroke patients were randomized to the vibration group (n = 12) or control group (n = 12). The vibration was applied at a 30 Hz frequency to the forearm extensor muscles with a local vibration device three days a week after the routine, conventional physical therapy sessions for four weeks. Six vibration sets were applied, including one vibration for one minute and a rest for 2 min. Routine, traditional physical therapy was used for the control group in 60-min sessions for 4 weeks. Patients were assessed for muscle activation with surface electromyography (MVC) and The Wolf Motor Function Test (WMFT), Functional Independent Test (FIM) was applied to all patients before and after treatment.

RESULTS

As a result of our study, MVC measurement, WMFT and FIM scores of the vibration group showed more improvement than the control group. Measurement results of vibration group; While MVC measurement increased from 10.21 to 13.79, WMFT-Functional Ability score increased from 42 to 50, WMFT-Performance Time duration increased from 68.78 to 61.83, and FIM score increased from 74.5 to 83. and the measurement results of the control group; MVC measurement increased from 12.28 to 12.22, WMFT-Functional Ability score increased from 48.5 to 51, WMFT-Performance Time duration increased from 70.39 to 70.61, and FIM score increased from 72.5 to 80.5.

CONCLUSION

It was concluded that low-frequency local vibration applied to the forearm extensor muscles improve forearm extensor muscle activation and hand motor function.

CLINICAL TRIAL REGISTRATION

NCT04562220.

Daily Vibrotactile Stimulation Exhibits Equal or Greater Spasticity Relief Than Botulinum Toxin in Stroke

OBJECTIVE

To test the feasibility and efficacy of the VibroTactile Stimulation (VTS) Glove, a wearable device that provides VTS to the impaired limb to reduce spastic hypertonia.

DESIGN

Prospective 2-arm intervention study-including 1 group of patients who use Botulinum toxin (BTX-A) for spasticity and 1 group of patients who do not use BTX-A.

SETTING

Participants were recruited through rehabilitation and neurology clinics.

PARTICIPANTS

Patients with chronic stroke (N=20; mean age=54 years, mean time since stroke=6.9 years). Patients who were previously receiving the standard of care (BTX-A injection) were eligible to participate and started the intervention 12 weeks after their last injection.

INTERVENTION

Participants were instructed to use the VTS Glove for 3 hours daily, at home or during everyday activities, for 8 weeks.

MAIN OUTCOME MEASURES

Spasticity was assessed with the Modified Ashworth Scale and the Modified Tardieu Scale at baseline and then at 2-week intervals for 12 weeks. Primary outcomes were the difference from baseline and at week 8 (end of VTS Glove use) and week 12 (4 weeks after stopping VTS Glove use). Patients who were receiving BTX-A were also assessed during the 12 weeks preceding the start of VTS Glove use to monitor the effect of BTX-A on spastic hypertonia. Range of motion and participant feedback were also studied.

RESULTS

A clinically meaningful difference in spastic hypertonia was found during and after daily VTS Glove use. Modified Ashworth and Modified Tardieu scores were reduced by an average of 0.9 (P=.0014) and 0.7 (P=.0003), respectively, at week 8 of daily VTS Glove use, and by 1.1 (P=.00025) and 0.9 (P=.0001), respectively, 1 month after stopping VTS Glove use. For participants who used BTX-A, 6 out of 11 showed greater change in Modified Ashworth ratings during VTS Glove use (mean=-1.8 vs mean=-1.6 with BTX-A) and 8 out of 11 showed their lowest level of symptoms during VTS Glove use (vs BTX-A).

CONCLUSIONS

Daily stimulation from the VTS Glove provides relief of spasticity and hypertonia. For more than half of the participants who had regularly used BTX-A, the VTS Glove provided equal or greater symptom relief.

Early protection against bone stress injuries by mobilization of endogenous targeted bone remodeling

Bone stress injuries are common overuse injuries, especially in soldiers, athletes, and performers. In contrast to various post-injury treatments, early protection against bone stress injuries can provide greater benefit. This study explored the early protection strategies against bone stress injuries by mobilization of endogenous targeted bone remodeling. The effects of various pharmaceutical/biophysical approaches, individual or combinational, were investigated by giving intervention before fatigue loading. We optimized the dosage and administration parameters and found that early intervention with pulsed electromagnetic field and parathyroid hormone (i.e., PEMF+PTH) resulted in the most pronounced protective effects among all the approaches against the bone stress injuries. In addition, the mechanisms by which the strategy mobilizes targeted bone remodeling and enhances the self-repair capacity of bone were systematically investigated. This study proposes strategies to reduce the incidence of bone stress injuries in high-risk populations (e.g., soldiers and athletes), particularly for those before sudden increased physical training.

Multimodal Care of a Patient With Functional Movement Disorders Following a Motor Vehicle Accident: A Case Report

Objective

The purpose of this case report was to describe the multimodal care of a patient with the sudden onset of truncal tremors.

Clinical Features

A 30-year-old female patient presented for chiropractic care with truncal tremors following a motor vehicle accident. Initial outcome measures included the Neck Disability Index (50%) and Oswestry Disability Index (62). The patient's truncal tremors became worse during spinal cord compression testing that included passive cervical flexion and slouched posture. The Romberg test was positive for swaying. Assessments of active range of motions of the cervical, thoracic, and lumbar spine were moderately reduced in all ranges. Case history, physical examinations, diagnostic imaging, and neurology consultations led to a diagnosis of functional truncal tremors. The patient was being concurrently managed by other health care providers. Magnetic resonance imaging studies were ordered by a neurologist and primary medical physician, which showed no structural abnormalities in brain neuroanatomy or spine.

Intervention and Outcome

The multimodal chiropractic care included whole-body vibration therapy (WBVT), spinal manipulative therapy (SMT), and acupuncture therapy. The treatment plan included 8 weekly appointments in which the patient received WBVT and SMT. During treatment weeks 2 to 6, the patient received acupuncture therapy, which occurred immediately following their treatment appointment for WBVT and SMT. The patient practiced stress reduction techniques, as advised by the neurologist, eliminated caffeine, and performed daily yoga exercises for 30 minutes. The Romberg test was negative after the third treatment. The patient was discharged after chiropractic visit 12, 95 days post-accident, as she reached maximal medical improvement. Truncal tremors were still present, but the patient described them as "barely noticeable."

Conclusion

The patient reported improvement under a course of chiropractic care using a multimodal approach, including behavioral, pharmacological, and manual therapies. This case study suggests that WBVT, SMT, and acupuncture therapy may assist some patients with functional movement disorders.

Does vibration frequency and location influence the effect of neck muscle vibration on postural sway? A cross-sectional study in asymptomatic participants

INTRODUCTION

Postural control is of utmost importance for human functioning. Cervical proprioception is crucial for balance control. Therefore, any change to it can lead to balance problems. Previous studies used neck vibration to change cervical proprioception and showed changes in postural control, but it remains unknown which vibration frequency or location causes the most significant effect. Therefore, this study aimed to investigate the effect of different vibration frequencies and locations on postural sway and to serve as future research protocol guidance.

METHODS

Seventeen healthy young participants were included in the study. We compared postural sway without vibration to postural sway with six different combinations of vibration frequency (80, 100, and 150 Hz) and location (dorsal neck muscles and sternocleidomastoid). Postural sway was evaluated using a force platform. The mean center of pressure (CoP) displacement, the root mean square (RMS), and the mean velocity in the anteroposterior and mediolateral direction were calculated, as well as the sway area. The aligned rank transform tool and a three-way repeated measures ANOVA were used to identify significant differences in postural sway variables.

RESULTS

Neck vibration caused a significant increase in all postural sway variables (p < 0.001). Neither the vibration frequency (p > 0.34) nor location (p > 0.29) nor the interaction of both (p > 0.30) influenced the magnitude of the change in postural sway measured during vibration.

CONCLUSION

Neck muscle vibration significantly changes CoP displacement, mean velocity, RMS, and area. However, we investigated and found that there were no significant differences between the different combinations of vibration frequency and location.

Dataset of single and double faults scenarios using vibration signals from a rotary machine

This dataset includes vibration sensor data from accelerometers located on the support bearings on a rotary machine designed as a fault simulator. Data collection for known faulty components include: bearing inner and outer raceway faults and bent shaft. 38 singles and double fault scenarios and a one no fault scenario were collected at three different operating frequencies (shaft rpm). Data was collected for approximately 10 seconds per scenario at a rate of 6400 hertz. Data can be used for machine learning classification.

University of Ottawa constant load and speed rolling-element bearing vibration and acoustic fault signature datasets

The collection and analysis of data play a critical role in detecting and diagnosing faults in bearings. However, the availability of large open-access rolling-element bearing datasets for fault diagnosis is limited. To overcome this challenge, the University of Ottawa Rolling-element Bearing Vibration and Acoustic Fault Signature Datasets Operating under Constant Load and Speed Conditions are introduced to provide supplementary data that can be combined or merged with existing bearing datasets to increase the amount of data available to researchers. This data utilizes various sensors such as an accelerometer, a microphone, a load cell, a hall effect sensor, and thermocouples to gather quality data on bearing health. By incorporating vibration and acoustic signals, the datasets enable both traditional and machine learning-based approaches for rolling-element bearing fault diagnosis. Furthermore, this dataset offers valuable insights into the accelerated deterioration of bearing life under constant loads, making it an invaluable resource for research in this domain. Ultimately, these datasets deliver high quality data for the detection and diagnosis of faults in rolling-element bearings, thereby holding significant implications for machinery operation and maintenance.

Multi-phase composite synchronization of three vibrators in a space far-resonant vibration system

To improve the problem that self-synchronization and control synchronization of vibration systems are respectively restricted by their inherent characteristics and product cost, by combining them a multi-phase composite synchronization scheme is proposed for space far-resonant vibration system actuated by three vibrators. Based on the established mathematical model and sliding mode control (SMC) algorithm, controller of one vibrator is designed to implement the multi-phase control synchronization. Then self-synchronization mechanism of the other two vibrators is analyzed through small parameter average method and Routh-Hurwitz criterion. Besides, necessary calculation and simulation cases in multi-phase composite synchronization state are further conducted. Research results indicate that the multi-phase composite synchronization of three vibrators can be carried out in stable operation regions, but chaotic behaviors, since severe mass asymmetry of the eccentric rotors (ERs), will be induced when the phase differences (PDs) between two coaxial vibrators are controlled in -1.99∼-1.67 and 1.63∼2.1 (rad), and the controlled PDs around -0.4 (rad) should be avoid to ensure a stronger synchronization ability.

Inhibitory Effects of Prolonged Focal Muscle Vibration on Maximal Grip Strength and Muscle Activity of Wrist and Extrinsic Finger Flexor Muscles

Objective

The objective of this study was to identify effective stimulus time by quantifying the inhibitory effects of focal muscle vibration (FMV) on maximal grip strength and muscle activities of the wrist and extrinsic finger flexors.

Methods

A randomized repeated-measures design was used in this study. A total of 22 healthy volunteers (mean age, 20.9 years) participated. An FMV of 86 Hz was applied to the anterior surface of the distal forearm under the following 3 conditions: no FMV (control), 5-minute FMV, and 10-minute FMV. Maximal grip strength was measured before and after FMV. The muscle activities of the flexor digitorum superficialis, flexor digitorum profundus (FDP), and flexor carpi ulnaris were simultaneously recorded using surface electromyography. Discomfort and complications following FMV were also assessed.

Results

Compared with the control group, a significant decrease in muscle activity was observed in both the flexor digitorum superficialis and flexor carpi ulnaris after 5 and 10 minutes of FMV. In contrast, there was no significant decrease in the maximal grip strength or FDP muscle activity after either FMV condition. The discomfort was significantly higher immediately after both FMV conditions than in the control group, but it decreased 15 minutes after FMV, indicating no significant difference among the 3 conditions. Redness and/or swelling were observed in 13.6% and 36.3% of the participants after 5 and 10 minutes of FMV, respectively.

Conclusion

Five-minute FMV to the distal forearm could be a useful therapeutic method with few complications. However, the FMV in this area alone was not sufficient to suppress the muscle activity of the FDP located in the deep layer.

Effectiveness and safety of subthreshold vibration over suprathreshold vibration in treatment of muscle fatigue in elderly people

Muscle fatigue is common in many populations, particularly elderlies. Aging increases the incidence of muscle fatigue and delays its recovery. There is a huge debate about the current treatments for muscle fatigue, particularly in elderlies. Recently, it has been discovered that mechanoreceptors have an important role as a sensory system in sensing muscle fatigue which could enhance the body's response to muscle fatigue. The function of mechanoreceptors could be enhanced by applying either suprathreshold or subthreshold vibration. Although suprathreshold vibration improves muscle fatigue, it can cause desensitization of cutaneous receptors, discomfort, and paresthesia, which are barriers to clinical use. Subthreshold vibration has been approved as a safe and effective method of training for mechanoreceptors; however, its use and effectiveness in muscle fatigue have never been tested or explained. Possible physiological effects of subthreshold vibration in the treatment of muscle fatigue include: (1) Enhancing the function of mechanoreceptors themselves; (2) Increasing the firing rate and function of alpha motor neurons; (3) Increasing blood flow to fatigued muscles; (4) Decreasing the rate of muscle cell death in elderlies (sarcopenia); and (5) Driving motor commands and allow better performance of muscles to decrease fatigue incidence. In conclusion, the use of subthreshold vibration could be a safe and effective treatment for muscle fatigue in elderlies. It could enhance recovery from muscle fatigue. Finally, Subthreshold Vibration is safe and effective in treating muscle fatigue in comparison to suprathreshold vibration.

Concordance between the Stockholm Workshop Scale and the International Consensus Criteria for grading the severity of neurosensory manifestations in hand-arm vibration syndrome in a Swedish clinical setting

OBJECTIVES

Occupational exposure to vibration using hand-held tools may cause hand-arm vibration syndrome (HAVS). Correct diagnosis and grading of severity are crucial in protecting the individual's health and for workers' compensation claims. The International Consensus Criteria (ICC) has been suggested to replace the widely used Stockholm Workshop Scale (SWS). The aims were to, in a clinical setting, assess the concordance between the SWS and the ICC neurosensory severity grading of vibration injury, and to present the clinical picture according to symptoms, type of affected nerve fibres and the relation between vascular and neurosensory manifestations.

METHODS

Data were collected from questionnaires, clinical examination and exposure assessment of 92 patients with HAVS. The severity of neurosensory manifestations was classified according to both scales. The prevalence of symptoms and findings was compared across groups of patients with increasing severity according to the SWS.

RESULTS

Classification with the ICC resulted in a shift towards lower grades of severity than with the SWS due to a systematic difference between the scales. Affected sensory units with small nerve fibres were far more prevalent than affected units with large nerve fibres. The most prevalent symptoms were numbness (91%) and cold intolerance (86%).

CONCLUSIONS

Using the ICC resulted in lower grades of the severity of HAVS. This should be taken into consideration when giving medical advice and approving workers' compensation. Clinical examinations should be performed to detect affected sensory units with both small and large nerve fibres and more attention should be paid to cold intolerance.

An analysis of nonlinear thickness vibration frequencies of multi-layered film bulk acoustic resonators

The fast reduction of the physical size of film bulk acoustic wave resonators as a layered structure implies the intensification of the electric field which can induce large deformation in the functioning state of devices as a circuit element. Consequently, the nonlinear behavior of the resonator and accompanying properties are to be included and evaluated in the development and optimization for performance improvement. With this objective, the nonlinear formulation of a multilayered film bulk acoustic resonator is presented for the analysis of vibration frequencies and mode shapes with the consideration of larger mechanical deformation. The dominantly linear relationship between the voltage or deformation and frequency is obtained to understand the nonlinear behavior and properties which have been subjected to extensive research analytically and experimentally to satisfy the application needs in all modes of communications and network technology.

Focal Vibration in dysphagia: a technological treatment for Severe Acquired Brain Injury rehabilitation

BACKGROUND

A patient with severe Acquired Brain Injury (sABI) may experience impairment in the physiological swallowing process. Many studies in the rehabilitation field have sought to understand the effects of local vibration therapy at various levels of the central nervous system and the possible benefits in neuro-rehabilitation. There are few studies directed toward the use of vibratory energy for improving swallowing and phonatory function.

OBJECTIVES

The purpose of this study is to observe the effects of integrating conventional dysphagia therapy with the focal vibration therapy in patients with sABI.

METHODS

This is a pilot, randomized controlled, parallel-arm, single-blind study. Twenty-eight patients with post-sABI dysphagia were included in the study and randomized to Conventional Group (CG, conventional treatment for dysphagia) or Experimental Group (EG, conventional treatment for dysphagia plus focal vibration therapy). Patients were assessed at baseline (T0), after 4 weeks (T1) and after 8 weeks (T2) using the Dysphagia Outcome Severity Scale (DOSS) and the Bedside Swallow Assessment scale (BSAs).

RESULTS

Patients in the experimental group showed a statistically significant change at T1 compared with T0 at DOSS (p=0.014), and at BSAS between T1 and T2 (p=0.024) and between T0 and T2 (p=0.027). Overall, all patients improved significantly at DOSS between T0 and T1 (p<0.001) and between T0 and T2 (p<0.001).

CONCLUSION

The results obtained from this pilot study are encouraging and demonstrate how the use of focal vibration therapy in add on to conventional treatment for dysphagia may be another useful tool for improving swallowing in patients with sABI.

Effect of low-magnitude, variable-frequency vibration therapy on pain threshold levels and mobility in adults with moderate knee osteoarthritis-randomized controlled trial

BACKGROUND

Osteoarthritis (OA) is one of the most commonly recorded diseases in clinical practice. Vibration therapy has been suggested for the treatment of knee OA. The purpose of the study was to determine the impact of vibrations of variable frequency and low amplitude on pain perception and mobility in patients suffering from knee OA.

METHODS

Thirty-two participants were allocated into two groups - Group 1 (oscillatory cycloidal vibrotherapy-OCV) and Group 2-control (sham therapy). The participants were diagnosed with moderate degenerative changes in the knee (grade II based on the Kellgren-Lawrence (KL) Grading Scale). Subjects received 15 sessions of vibration therapy and sham therapy respectively. Pain, range of motion, and functional disability were assessed through Visual Analog Scale (VAS), Laitinen questionnaire, goniometer (ROM - range of motion), timed up and go test (TUG) and Knee Injury and Osteoarthritis Outcome Score (KOOS). Measurements were taken at baseline, after the last session and four weeks after the last session (follow up). T-test and U-Mann Whitney test compare baseline characteristics. The Wilcoxon and ANOVA tests compared mean VAS, Laitinen, ROM, TUG and KOOS. The significant P-value was less than 0.05.

RESULTS

After 3 weeks (15 sessions) of vibration therapy, reduced the sensation of pain and improved mobility was recorded. There was a more significant improvement in the vibration therapy group than the control group in pain alleviation on VAS scale (p < 0.001), on Laitinen scale (p < 0.001), knee ROMs flexions (p < 0.001) and TUG (p < 0.001) at the last session. KOOS score with pain indicator, symptoms, activities of daily living, function in sport and recreation and knee related quality of life improved more in the vibration therapy group than the control group. Effects maintained up to 4 weeks in vibration group. No adverse events were reported.

CONCLUSIONS

Our data demonstrated that the use of vibrations of variable frequency and low amplitude in patients with the knee OA is a safe and effective therapy. It is recommended to increase the number of treatments performed, primarily in patients with degeneration II° according to the KL classification.

TRIAL REGISTRATION

Prospectively registered on ANZCTR ( ACTRN12619000832178 ). Registered on 11 June 2019.

Vibration and current dataset of three-phase permanent magnet synchronous motors with stator faults

Permanent magnet synchronous motors (PMSM) are widely used in industry applications such as home appliances, manufacturing process, high-speed trains, and electric vehicles. Unexpected faults of PMSM are directly related to the significant losses in the engineered systems. The majority of motor faults are bearing fault (mechanical) and stator fault (electrical). This article reports vibration and driving current dataset of three-phase PMSM with three different motor powers under eight different severities of stator fault. PMSM conditions including normal, inter-coil short circuit fault, and inter-turn short circuit fault in three motors are demonstrated with different powers of 1.0 kW, 1.5 kW and 3.0 kW, respectively. The PMSMs are operated under the same torque load condition and rotating speed. Dataset is acquired using one integrated electronics piezo-electric (IEPE) based accelerometer and three current transformers (CT) with National Instruments (NI) data acquisition (DAQ) board under international organization for standardization standard (ISO 10816-1:1995). Established dataset can be used to verify newly developed state-of-the-art methods for PMSM stator fault diagnosis. Mendeley Data. DOI: 10.17632/rgn5brrgrn.5.

A neuromuscular human body model for lumbar injury risk analysis in a vibration loading environment

BACKGROUND AND OBJECTIVE

Long-term intensive exposure to whole-body vibration substantially increases the risk of low back pain and degenerative diseases in special occupational groups, like motor vehicle drivers, military vehicle occupants, aircraft pilots, etc. This study aims to establish and validate a neuromuscular human body model focusing on improvement of the detailed description of anatomic structures and neural reflex control, for lumbar injury analysis in vibration loading environments.

METHODS

A whole-body musculoskeletal in Opensim codes was first improved by including a detailed anatomic description of spinal ligaments, non-linear intervertebral disc, and lumbar facet joints, and coupling a proprioceptive feedback closed-loop control strategy with GTOs and muscle spindles modeling in Python codes. Then, the established neuromuscular model was multi-levelly validated from sub-segments to the whole model, from regular movements to dynamic responses to vibration loadings. Finally, the neuromuscular model was combined with a dynamic model of an armored vehicle to analyze occupant lumbar injury risk in vibration loadings due to different road conditions and traveling velocities.

RESULT

Based on a series of biomechanical indexes, including lumbar joint rotation angles, the lumbar intervertebral pressures, the displacement of the lumbar segments, and the lumbar muscle activities, the validation results show that the present neuromuscular model is available and feasible in predicting lumbar biomechanical responses in normal daily movement and vibration loading environments. Furthermore, the combined analysis with the armored vehicle model predicted similar lumbar injury risk to the experimental or epidemiologic studies. The preliminary analysis results also showed that road types and travelling velocities have substantial combined effects on lumbar muscle activities, and indicated that intervertebral joint pressure and muscle activity indexes can need to be jointly considered for lumbar injury risk evaluation.

CONCLUSION

In conclusion, the established neuromuscular model is an effective tool to evaluate vibration loading effects on injury risk of the human body and assist vehicle design vibration comfort by directly concerning the human body injury itself.

A mathematical approach to estimate micro-displacement of a dental implant using electromagnetic Frequency Response Analysis

The aim of this paper is to formulate a mathematical model of dental prosthetic using single degree of freedom (SDOF) to assess the micro-displacement under electromagnetic excitation. Using Finite Element Analysis (FEA) and values from literature, stiffness and damping values of the mathematical model were estimated. For ensuring the successful implantation of dental implant system, monitoring of primary stability in terms of micro-displacement is crucial. One of the most popular techniques for the measurement of stability is the Frequency Response Analysis (FRA). This technique assesses the resonant frequency of vibration corresponding to the maximum micro-displacement (micro-mobility) of the implant. Among the different FRA techniques, the most common method is the Electromagnetic FRA. The subsequent displacement of the implant in the bone is estimated by equations of vibration. A comparison has been made to observe the variation in resonance frequency and micro-displacement due to varying input frequency ranges of 1-40 Hz. The micro-displacement and corresponding resonance frequency were plotted using MATLAB and the variation in resonance frequency is found to be negligible. The present mathematical model is a preliminary approach to understand the variation of micro-displacement with reference to electromagnetic excitation force and to obtain the resonance frequency. The present study validated the use of input frequency ranges (1-30 Hz) with negligible variation in micro-displacement and corresponding resonance frequency. However, input frequency ranges beyond 31-40 Hz is not recommended due to large variation in micromotion and corresponding resonance frequency.

Assessment of vibration modulated regional cerebral blood flow with MRI

Human brain experiences vibration of certain magnitude and frequency during various physical activities such as vehicle transportation and machine operation, which may cause traumatic brain injury or other brain diseases. However, the mechanisms of brain pathogenesis due to vibration are not fully elucidated due to the lack of techniques to study brain functions while applying vibration to the brain at a specific magnitude and frequency. Here, this study reported a custom-built head-worn electromagnetic actuator that applied vibration to the brain in vivo at an accurate frequency inside a magnetic resonance imaging scanner while cerebral blood flow (CBF) was acquired. Using this technique, CBF values from 45 healthy volunteers were quantitatively measured immediately following vibration at 20, 30, 40 Hz, respectively. Results showed increasingly reduced CBF with increasing frequency at multiple regions of the brain, while the size of the regions expanded. Importantly, the vibration-induced CBF reduction regions largely fell inside the brain's default mode network (DMN), with about 58 or 46% overlap at 30 or 40 Hz, respectively. These findings demonstrate that vibration as a mechanical stimulus can change strain conditions, which may induce CBF reduction in the brain with regional differences in a frequency-dependent manner. Furthermore, the overlap between vibration-induced CBF reduction regions and DMN suggested a potential relationship between external mechanical stimuli and cognitive functions.

Reduction of vibration and noise pollution from agricultural tractor engine using novel pine oil and soapnut oil methyl ester as fuel

The exhaust emissions from automotive diesel engines are successfully controlled over the years by adopting different combustion strategies and after treatment devices, whereas the combustion induced vibration and noise are the major pollutant in off-road vehicle engines and yet to be optimized. In the present study, a twin cylinder, Simpson's S-217 tractor diesel engine was used to evaluate the performance, combustion, vibration, and noise characteristics, using biofuel blends. For this study, the blends of pine oil - soapnut oil biodiesel (P75SNB25), diesel - soapnut oil biodiesel (SNB20) and diesel were used as fuel. The pine oil used in this research was purchased and used in its neat form. The soapnut oil was extracted from the soapnut seeds by cold pressing method and trans-esterified in two stages by using methanol and catalysts. The experimental results revealed that the performance and combustion characteristics of the blend P75SNB25 was superior to diesel and the blend SNB20 was slightly inferior to diesel. For the blend P75SNB25, the amplitude of acceleration with respect to time was reduced by 19.48% and 11.58% at no load and full load conditions respectively, whereas for the blend SNB20, the amplitude of acceleration showed a reduction of 14.27% and 9.46% at no load and full load conditions respectively in comparison with diesel operation. But both the blends P75SNB25 and SNB20 showed a maximum reduction of noise by 2.34% at different engine loads compared to diesel operation.

The effects of vibration on the neuronal activity of lateral vestibular nuclei in unilaterally labyrinthectomized rats

Unilateral labyrinthectomy causes distinct oculomotor and postural disorder syndromes that gradually deteriorate. Simultaneously, compensatory mechanisms for the suppression of pathological disorders were activated. The current study aimed to investigate the characteristics of impulse activity in the ipsilateral and contralateral neurons of the lateral vestibular nucleus of unilaterally labyrinthectomized rats during various periods of vibration exposure. A program analysis of the background impulse activity of the neurons in the right- and left-lateral vestibular nuclei of rats under normal condition and after right-sided labyrinthectomy was performed. The animals were subjected to different periods of vibration exposure 2 days after surgery (5-, 10-, and 15-day periods). A comparison of the characteristics of the background impulse activity of neurons in both nuclei of intact rats revealed an initial asymmetry in the values of the mean impulse frequency and coefficient of variation of interimpulse intervals. After 5 days of vibration exposure, the values of the mean impulse frequency of neurons in both Deiters' nuclei were almost equal in labyrinthectomized rats. The mean impulse frequency of neurons on the uninjured side was higher than that on the injured side on the days following vibration exposure. The characteristics and functional significance of the findings are discussed.

[Evaluation of the results and feasibility of vibration, diuresis and inversion therapy in the treatment of upper urinary tract stones]

OBJECTIVES

To evaluate the feasibility, efficiency, and predictive factors of therapeutic success of Vibration, Diuresis and Inversion (VDI) therapy for the removal of upper urinary tract stones.

METHODS

It is a retrospective, single-center study at the CHU - La Conception, Marseille, France including all patients treated with VDI from 2013 to 2018. VDI was indicated for stones <6mm in first-line treatment or for residual fragments <6mm after ureteroscopy, PCNL, microPCNL. The protocol included 4 sessions in outpatient care from 2013 to 2015 then 6 sessions from 2015 to 2018 and a final radiological evaluation.

RESULTS

In total, 109 patients or 489 sessions are reported: median age was 55 years [14-84], median BMI 25kg/m² [15-37], average cumulative size of kidney stones 3mm ±4. VDI was performed after flexible ureteroscopy (62%), SWL (20%), percutaneous treatment (9%) or as a first-line treatment (9%). Compliance was 87 %. The median VAS during the session was 0[0-8]. The incidence of post-session renal colic was 4% (all Clavien I). The postoperative fragment-free and microfragment rates were respectively 39% and 21%, i.e. an overall success of 60% for kidney stones, and 43% and 21%, i.e. an overall success of 64% for lower pole kidney stones.

CONCLUSION

VDI is a simple, non invasive and well tolerated technique for the elimination of small renal lithiasis after SWL, ureteroscopy, PCNL or as a first-line treatment.

Vibration motor stimulation device in smart leggings that promotes motor performance in older people

Globally, accelerated aging is taking place alongside increased life expectancy of the population. This poses a challenge to maintaining autonomy and independence as people age but preventing falls and disabilities. Currently, there are few specific technologies on the market that are focused on the rehabilitation and promotion of autonomy in older adults. This study presents the development of a prototype (Myoviber®) of a low-cost, wearable everyday garment, designed to stimulate the lower limbs by the application of focal muscle vibration and incorporating technical textile qualities. The presented approach is proactive and preventive, maintaining functionality for the elderly while integrating electronic technology into an everyday garment. For this, a comprehensive study was carried out that included the design of the leggings through anthropometric analyses, the development of vibration devices at a stable frequency located in the knee extensor muscle and a smart belt with wireless connection, and the optimization of the battery autonomy. The development of the prototype was carried out through the construction of a vibratory device, which was validated with biomechanical evaluations. The results show an increase in the functional capacity of the lower limbs, in relation to motor tasks such as postural balance and gait in older people.

Change of Phonation in Canines Without Vocal Fold Paralysis After Vocal Processes Resection

The effects of the vocal processes resection on phonation in an animal without vocal fold paralysis have not been clarified. The present study used an in vivo animal model with vocal processes resection and excised larynges phonation model to investigate the effects of the vocal processes resection on phonation. Six months after resection of bilateral vocal fold processes, glottal airflow, subglottal air pressure, acoustic signals, and ultra-high-speed video images were recorded in the excised larynges phonation model of canine. Glottal aerodynamic parameters were estimated by calculation of subglottal pressure and glottal flow. Histological analyses of the scarred were assessed for wound healing completion. In the vocal processes resection group, fundamental frequency(F0) and vocal intensity decreased, and the Jitter and Shimmer increased significantly. The phonation threshold power(PTW) of the vocal processes resection was significantly higher than controls. The vibratory amplitude of the vocal fold posterior and visual vocal fold vibration length increased. Expression of collagen I-III in scarred tissue samples in vocal process resection was similar to controlling soft tissue specimens around vocal process cartilage, and collagen fiber formed matured thick bundles. The results suggest that the F0, voice quality, and vocal intensity significantly decreased after complete wound healing of vocal processes resection in canines without vocal folds paralysis. The higher PTW and posterior scarred vocal vibration may be the dynamic reasons.

The effects of whole-body vibration and head supported mass on performance and muscular demand

For military rotary-wing aircrew, little is known about the interactive effects of vibration exposure and the addition of head supported mass (HSM) on target acquisition performance, head kinematics, and muscular demand. Sixteen healthy male participants wore an aviator helmet with replica night vision goggles and completed rapid aiming head movements to acquire visual targets in axial and off-axis movement trajectories while secured in a Bell-412 helicopter seat mounted to a human-rated shaker platform. HSM configuration (with or without a counterweight (CW)) and vertical whole-body vibration (WBV) conditions (vibration or no vibration exposure) were manipulated as independent variables. WBV exposure degraded target acquisition performance and lengthened time to peak velocity of head movements. For yaw peak velocity in the axial movement trajectory, peak velocity was 9.9%, 11.6%, and 8.4% higher in the noCW + WBV condition compared to the CW + WBV, CW + noWBV, and noCW + noWBV conditions, respectively.Practitioner summary: The majority of military helicopter aircrew use a counterweight to counteract the anteriorly displaced load of night vision googles. This study was undertaken to better understand how helicopter vibration and counterweight use interactively affect performance and health-related measures during rapid scanning head movements.

Shoulder vibratory exercises improves shoulder external rotation muscle strength and shoulder function: Randomized comparison trial

BACKGROUND

Based on electromyography measurements, shoulder vibratory exercises efficiently stimulate shoulder muscles activity. Yet very few studies have supported that shoulder vibratory exercises increased shoulder muscles strength and function, and the noninferiority compared with conventional elastic resistance exercises remains unknown.

OBJECTIVE

This study investigated the effect of vibratory exercises versus conventional elastic resistance exercises with elastic bands on shoulder external rotation muscles strength and functional performance in young adults.

METHODS

26 young adults (7 males and 19 females, with age 23.89 ± 3.02) were recruited and randomly allocated to shoulder vibratory exercises with FLEXI-BAR (FLEXI-BAR group) or conventional resistance exercises with elastic band (TheraBand group) for 3 times/week, 4 weeks totally. Shoulder external rotator muscles strength test and Underkofler softball distance throw test (USDTT) were performed before and after the training period.

RESULTS

After 4 weeks training, shoulder external rotator muscles strength increased 22.25 ± 15.06 N (P= 0.004, effect size = 1.48) within FLEXI-BAR group and 22.81 ± 14.94 N (P= 0.007, effect size = 1.53) within TheraBand group. There were no statistically significant differences between groups in the three muscle strength tests (P> 0.65). Regarding shoulder function, FLEXI-BAR exercises increased the throw distance 0.81 ± 0.92 meters in USDTT (P= 0.041, effect size = 0.88) while TheraBand exercise did not (P= 0.284), yet there was no statistically significant between group effects (P= 0.608).

CONCLUSIONS

These findings suggest that shoulder vibratory exercises can improve shoulder muscles strength in young adults and can be a useful alternative to the conventional elastic resistance exercises to improve the shoulder muscles strength and function. This provides therapists with more options in terms of choosing training equipment for rehabilitation programs.

Association between physical risk factors and sleep disturbance among workers in Korea: The 5th Korean Working Conditions Survey

OBJECTIVE

Sleep disturbance is associated with negative effects to workers' health and productivity; hence, it is important to find which population of workers are associated with sleep disturbance. This study aimed to investigate the association between physical risk factors (vibration, noise, high, and low temperatures) and sleep disturbance in the Korean working population.

METHODS

We analyzed data on 29,213 paid workers from the 5th Korean Working Conditions Survey. Individual and occupational characteristics, physical risk factors exposure, and sleep disturbance were collected using self-reported questionnaires. To assess the association between physical risk factors and sleep disturbance, the chi-square test and multivariable logistic regression models were conducted. All statistical analyses were performed in sex-based subgroups.

RESULTS

We observed that all physical risk factors are associated with sleep disturbance. The adjusted odds ratios (95% confidence interval [CI]) of severe exposure to vibration, noise, high and low temperature were 1.69 (CI:1.47-1.94), 2.52 (CI:2.17-2.92), 3.09 (CI:2.69-3.56), and 1.96 (CI:1.68-2.28) in male workers and 2.27 (CI:1.89-2.72), 3.52 (CI:2.92-4.24), 3.30 (CI:2.81-3.87), and 2.87 (CI:2.44-3.38) in female workers, respectively. The prevalence of sleep disturbance increased with increased exposure to physical risk factors, indicating a dose-response relationship.

CONCLUSIONS

Physical risk factors exposure in the workplace was associated with sleep disturbance of workers, indicating a dose-response relationship. Given the impact of sleep disturbance on workers' health and efficiency, it may be important to control exposure to physical risk factors in the working environment with regards to sleep conditions.

Vibratory and plantar pressure stimulation: Steps to improve freezing of gait in Parkinson's disease

INTRODUCTION

Freezing of gait (FOG) is a devastating symptom that develops in patients with advanced Parkinson's disease (PD) and is often unresponsive to pharmacological treatment. Recent research suggests that FOG may result from dysfunctional plantar peripheral sensory systems. The impact of combined plantar pressure and vibratory stimulation over vibratory or pressure alone on FOG remains unexplored.

METHODS

PD patients with FOG were randomised into four groups and treated with combined vibratory and pressure stimulation, vibratory stimulation alone, pressure stimulation alone, or controls (no stimulation). Vibratory stimulation targeted both Achilles' tendons. Simultaneous bilateral pressure stimulation was applied to the first hallux, first metatarsal bone, and the sole. The primary outcome included normalized percent changes in percent FOG measured both pre- and immediately post-stimulation. Other outcomes including clinical rating scale, response to questionnaires, number and duration of freezing episodes, and spatiotemporal gait parameters at pre- and freezing episodes were also explored.

RESULTS

Sixty PD patients participated in the study. Patients who were treated with combined vibratory and pressure stimulation responded with significant decreases in normalized percent changes of percent FOG (62.75 ± 25.54%, p < 0.001) compared with those treated with vibration alone (11.38 ± 8.29%, p < 0.001), pressure alone (15.15 ± 16.18%, p < 0.001), or controls (8.59 ± 16.85%, p < 0.001).

CONCLUSION

Our study demonstrated the benefit of combined vibratory and pressure stimulation on FOG suggesting that this strategy might be developed as a novel treatment modality for PD patients with FOG.