Analysis of biomechanical passive synergistic vibration reduction inspired by the structure, morphology, nano-mechanics of the beetles' hindwing.

Using scanning electron microscopy (SEM), a small animal imaging system, and biological tissue sections, the relationships between the flapping vibrations in the hindwings of Trypoxylus dichotomus and their morphology, structure, and hemolymph dynamics were investigated. Based on these findings, a three-degree-of-freedom (3-DOF) model incorporating nano-mechanical properties was developed to investigate spanwise passive synergistic vibration reduction (PSVR) in the hindwing elements. To ensure precision, the Runge-Kutta and incremental harmonic balance (IHB) methods were employed for both solving and comparing solutions. Analysis of the spanwise force (FOX) signals confirmed the validity of the PSVR model. Parametric analysis revealed that reducing system mass and stiffness increased the resonance amplitude while shifting the resonance frequency in the opposite direction. The resonance frequency and flexible deformation amplitude of the hindwing system could be controlled by adjusting mass and stiffness within the synergistic framework. The mass and damping of the wing base, along with the stiffness of the wing membrane, were identified as critical factors in the system. This model provides valuable insights into the PSVR mechanism, potentially informing the design and manufacture of bionic flexible flapping wings.

Influence of the elevation effect of slope blasting on the vibration velocity of existing buried steel pipes.

Blasting vibration(BV) may cause the instability and damage to the surrounding structures and infrastructures, even leading to serious accident. As far as slope blasting is concerned, more and more attention has been paid to the elevation effect of BV of rock mass. However, scarce information is available on the influence of the elevation effect of slope blasting on the BV of surrounding structures, especially the existing buried pipes. As a consequence, the influence of the elevation effect of slope blasting on the BV of steel pipes was numerically investigated according to finite element model, which was verified against the experimental result. Moreover, the formula is presented to predict the peak vibration velocity (PVV) of steel pipes under slope blasting. It is found that PVV of the steel pipes has the elevation amplification effect in the terrain with positive or negative elevation difference. PVV of the pipes in the terrain with positive elevation difference is greater than that in the terrain with the same negative elevation difference. The elevation effect is more obvious under the condition of the positive elevation difference (2.1-5.1 m). The modified Sadovsky's empirical formula is more suitable to predict PVV of the buried steel pipes during the slope blasting process.

Electron microscopy of seismic waves.

Changes in the surrounding environment, if transmitted to the electron microscope, are frequently perceived as noise that diminishes the quality of the images. However, in fact, 'noises' contain rich information about the environment. This work reports a very rare event where aberration-corrected HAADF-STEM images were acquired during the impact of seismic waves, resulted from a mild earthquake. By analysing these images, we found that the drift and vibration of the sample are detectable and quantifiable. Despite many potential challenges, this work demonstrates the utilisation of electron microscopes in detecting and monitoring seismic waves with high spatial resolution, which may lead to unique applications in the low-frequency regime.

Auditory pathway for detection of vibration in the tokay gecko.

Otolithic endorgans such as the saccule were thought to be strictly vestibular in amniotes (reptiles, birds, and mammals), with little evidence supporting the auditory function found in fish and amphibians (frogs and salamanders). Here, we demonstrate an auditory role for the saccule in the tokay gecko (Gekko gecko). The nucleus vestibularis ovalis (VeO) in the hindbrain exclusively receives input from the saccule and projects to the auditory midbrain, the torus semicircularis, via an ascending pathway parallel to cochlear pathways. Single-unit recordings show that VeO is exquisitely sensitive to low-frequency vibrations. Moreover, VeO is present in other lepidosaurs, including snakes and Sphenodon. These findings indicate that the ancestral auditory function of the saccule is likely preserved at least in the lepidosaurian lineage of amniotes and mediates sensitive encoding of vibration.

Dynamic response and vibration suitability analysis of the large-span double-connected structure under coupled wind and pedestrian loads.

Modern buildings increasingly utilize lightweight, high-strength materials and feature high-rise, large-span structural designs. These structures often exhibit low natural frequencies and are susceptible to resonance from low-frequency dynamic loads such as wind and pedestrian loads. This paper focuses on a large-span double-connected structure and analyzes its dynamic response under the combined effects of wind and pedestrian loads. First, a finite element model of the structure was created using ANSYS, and model validity verification and modal analysis were performed. Second, a Fourier-based pedestrian model was used to simulate pedestrian loads and generate time-range data. The pulsating wind speed was generated from the Davenport spectrum using the harmonic superposition method. Wind load time-range data were calculated for different heights using Bernoulli's theorem. Finally, the solution yields information about the dynamic response of the structure. The study revealed maximum vertical comfort ratings in the connecting corridor were achieved when crowd density did not exceed 0.3 persons/m2. The connecting corridor's most unfavorable horizontal comfort level was evaluated as a medium, except for the 0-degree wind angle condition. This paper provides experience in studying the dynamic response and vibration suitability assessment of the large-span double-connected structure under wind and pedestrian loads.

Impact of foam rolling with and without vibration on muscle oxidative metabolism and microvascular reactivity.

Background and Purpose: There is a growing interest in use vibration foam rolling as a warm up and recovery tool. However, whether vibration foam rolling offers additional benefits to traditional foam rolling is unclear. The current study aims to compare the effects of acute foam rolling, with and without vibration, on skeletal muscle metabolism and microvascular reactivity. Methods: Fifteen physically active young males were tested on two different days, with gastrocnemius muscle microvascular function assessed using near-infrared spectroscopy coupled with the post-occlusive reactive hyperemia technique, before and after foam rolling, performed with or without vibration. The slope of tissue saturation index (TSI) decrease during occlusion between 120 s to 150 s (TSI occlusion slope) was assessed for muscle metabolic rate. Three commonly used microvascular function indexes, including the first10s TSI slope after occlusion (TSI10), time for TSI to reach half of peak magnitude (TSI1/2), and TSI peak reactive hyperemia, were also assessed. Results: None of the measured indexes showed significance for interaction or method (all p > 0.05). However, there was a main effect for time for TSI occlusion slope, TSI1/2, and TSI peak reactive hyperemia (p = 0.005, 0.034 and 0.046, respectively). No main effect for time for TSI10 was detected (p = 0.963). Conclusions: The application of foam rolling can decrease muscle metabolism, and may improve some aspects of muscle microvascular function. However, vibration foam rolling does not seem to offer any additional benefits compared to traditional foam rolling alone.

Vitamin D combined with whole-body vibration training for the treatment of osteo-sarcopenia: study protocol for a randomized controlled trial.

BACKGROUND: Osteo-sarcopenia (OS) has become a global public health problem and a frontier research problem, as a combination of sarcopenia (SP) and osteoporosis (OP) diseases. The clinical performances include muscle weakness, systemic bone pain, standing difficulty, even falls and fractures, etc., which seriously affect the patient's life and work. The pathological mechanism of the OS may be the abnormal metabolism which disrupts the equilibrium stability of the musculoskeletal system. Therefore, this study combined vitamin D (Vit. D) and whole-body vibration training (WBVT) to intervene in subjects of OS, aiming to evaluate the effectiveness and safety of the diagnosis and treatment protocol and to explore the efficacy mechanism. METHODS: We propose a multicenter, parallel-group clinical trial to evaluate the efficacy and safety of Vit. D combined with WBVT intervention in OS. Subjects who met the inclusion or exclusion criteria and signed the informed consent form would be randomly assigned to the WBVT group, Vit. D group, or WBVT+ Vit. D group. All subjects will be treated for 1 month and followed up after 3 and 6 months. The primary outcomes are lumbar bone mineral density (BMD) and appendicular skeletal muscle mass (ASM) measured by dual-energy X-ray absorptiometry (DXA) and handgrip strength measured by grip strength meter. Secondary outcomes include serum markers of myostatin (MSTN), irisin and bone turnover markers (BTM), SARC-CalF questionnaire, 1-min test question of osteoporosis risk, patient health status (evaluated by the SF-36 health survey), physical performance measurement that includes 5-time chair stand test, 6-m walk, and the short physical performance battery (SPPB). DISCUSSION: If Vit. D combined with WBVT can well relieve OS symptoms without adverse effects, this protocol may be a new treatment strategy for OS. After therapeutic intervention, if the serum marker MSTN/irisin is significant, both have the potential to become sensitive indicators for screening OS effective drugs and treatments, which also indicates that WBVT combined with Vit. D plays a role in improving OS by regulating MSTN/irisin. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2400082269 . Registered on March 26, 2024.

Correlation between BMI, amount of aspirated fat and post-operative complications in VASER liposuction: A single centre experience.

Background: Vibration amplification of sound energy at resonance (VASER) liposuction is an innovative technique that allows surgeons to selectively remove fat and shape desired areas of the body, resulting in more precise and controlled outcomes compared to traditional liposuction techniques. VASER liposuction offers several advantages, including targeted action that reduces trauma to the surrounding tissues, limiting pain, swelling and recovery time. Purpose: This study compared the complication rates among patients who underwent VASER liposuction in relation to their body mass index (BMI) and the amount of fat aspirated. Methods: The authors reviewed the medical records of all patients who underwent VASER liposuction at Scalera Clinic in Naples, dividing them into two groups: the first with BMI < 24.9 kg/m2 and second with BMI >25.0 kg/m2. Results: The authors examined 117 patients who were operated on within a year (2022/2023), with 48 of them having BMIs < 24.9 kg/m2 and 69 showing BMIs >25.0 kg/m2. In patients with a BMI >25 kg/m2, the most common complications were contusion, hematomas and abnormal skin retraction, whereas no complications were observed in the patients with normal-weight. Conclusions: To minimise post-operative complications and maximise results, it is advisable to select patients based on their BMI assessment, the anatomy of the treated body area and the volume of fat to be removed. This approach aims to ensure that the patients are suitable for the procedure and the achieved results align with their aesthetic expectations.

Development and evaluation of an automated breathing-synchronized chest wall vibration stimulation system.

[Purpose] Vibratory stimulation of the upper intercostal region enhances inspiratory movement, whereas stimulation of the lower intercostal region enhances expiratory movement and ventilation. Previous vibration stimulation devices for intercostal muscles required manual stimulation, causing a time lag between breathing and vibration stimulation. The purpose of this experiment was to compare the effects of an automatic vibration stimulation system with manual vibration stimulation in a group of individuals and to verify whether there was an increase in upper and lower chest wall displacement and respiratory flow. [Participants and Methods] Twenty healthy adults were divided into two groups, as follows: an automatic vibration stimulation group using a chest wall vibration stimulation system and a manual vibration stimulation group. Vibration stimulation was applied to the second intercostal space on both sides during inspiration, and to the seventh intercostal space on both sides during expiration. [Results] The vibration stimulation system group showed significantly higher synchronization rates during inspiration and expiration than the manual vibration stimulation group, and there was a significant increase in chest wall displacement and respiratory flow during inspiration and expiration. [Conclusion] The chest wall vibration stimulation system can effectively provide vibration stimulation to the intercostal muscles in synchrony with breathing.

Distribution of Fibrosis-4 index and vibration-controlled transient elastography-derived liver stiffness measurement for patients with metabolic dysfunction-associated steatotic liver disease in health check-up.

AIMS: The multisociety consensus nomenclature has introduced steatotic liver disease (SLD) with diverse subclassifications, which are metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction and alcohol-associated steatotic liver disease (MetALD), alcohol-associated liver disease (ALD), specific etiology, and cryptogenic. We investigated their prevalence, as per the new definition, in individuals undergoing health check-ups. Additionally, we analyzed the distribution of Fibrosis-4 (FIB-4) index and vibration-controlled transient elastography (VCTE)-derived liver stiffness measurement (LSM) for MASLD. METHODS: In this cross-sectional study, 6530 subjects undergoing a health check-up in Japan were included. Conventional B-mode ultrasound was carried out on all 6530 subjects, and those with MASLD underwent VCTE. RESULTS: The prevalence of SLD was 39.5%, comprising MASLD 28.7%, MetALD 8.6%, ALD 1.2%, specific etiology SLD 0.3%, and cryptogenic SLD 0.7%. Subjects with VCTE-derived LSM ≥8 kPa constituted 2.1% of MASLD. FIB-4 ≥1.3 showed that the sensitivity, specificity, positive predictive value (PPV), and negative predictive value for diagnosing VCTE-derived LSM ≥8 kPa were 60.6%, 77.0%, 5.3%, and 98.9%, respectively. The referral rate to specialists was 23.8% using FIB-4 ≥1.30. "FIB-4 ≥1.3 in subjects <65 years and FIB-4 ≥2.0 in subjects ≥65 years" showed higher PPV (6.7%) and lower referral rate (17.1%) compared with FIB-4 ≥1.3, but the sensitivity (54.5%) did not show adequate diagnostic capability as a noninvasive test for diagnosing VCTE-derived LSM ≥8 kPa. CONCLUSIONS: Acknowledging the selection bias in hepatology centers, we undertook this prospective health check-up study. Although the FIB-4 index proves to be a convenient marker, it might not perform well as a primary screening tool for liver fibrosis in the general population (UMIN Clinical Trials Registry No. UMIN000035188).

Impact of whole-body vibration training on ankle joint proprioception and balance in stroke patients: a prospective cohort study.

BACKGROUND: Although whole-body vibration (WBV) training is acknowledged for its benefits in enhancing motor functions across several neurological disorders, its precise influence on ankle joint proprioception and balance in stroke patients is still not well understood. This research seeks to assess the impact of WBV training on ankle joint proprioception and balance in stroke patients, thereby filling this important research void. METHODS: In this prospective cohort study, thirty-five stroke patients were randomly assigned to either the WBV group (n = 17) or a control group (n = 18) using a random number table method. The control group received daily general rehabilitation for four weeks, while the WBV group received an additional 30 min of WBV training each day with the Trunsan S110 Vibration Training System. Blinded outcome assessments were conducted at baseline and post-treatment, utilizing the Berg balance scale (BBS), Functional reach test (FRT), Romberg test length (RTL) and area (RTA), and completion rates of ankle joint dorsiflexion-plantar flexion (DP) and inversion-eversion (IE) tests. Follow-up assessments were performed after four weeks of intervention, focusing on RTL, RTA, DP, and IE as primary outcomes. RESULTS: Analysis of intra-group changes from baseline to post-treatment revealed significant improvements across the BBS, FRT, RTL, RTA, and DP and IE assessments (p < 0.001). Notably, the WBV group showed significant enhancements compared to the control group in DP and IE (p < 0.001 and p < 0.05, respectively), with mean values increasing from 13.556 to 16.765 (23.7%) and from 5.944 to 8.118 (36.6%), respectively. However, WBV did not provide additional benefits over the control treatment for balance recovery parameters such as BBS, FRT, RTL, and RTA (p > 0.05). CONCLUSIONS: This study demonstrates that WBV therapy is equally effective as conventional methods in enhancing proprioception and balance in stroke patients, but it does not provide additional benefits for balance recovery. WBV significantly improves proprioceptive functions, particularly in DP and IE parameters. However, it does not surpass traditional rehabilitation methods in terms of balance recovery. These findings indicate that WBV should be incorporated into stroke rehabilitation primarily to enhance proprioception rather than to optimize balance recovery. TRIAL REGISTRATION: This study was retrospectively registered in the ISRCTN Registry on 29/07/2024 ( https://www.isrctn.com/ , ISRCTN64602845).

Effect of spider's weight on signal transmittance in vertical orb webs.

Spider orb web is a sophisticated structure that needs to fulfil multiple roles, such as trapping prey and transmitting web-borne signals. When building their web, heavier spiders tend to increase the pretension on the web, which seems counterintuitive since a tighter web would decrease the chances of stopping and retaining prey. In this article, we claim that heavier orb-weaving spiders increase tension on the web in order to reduce the attenuation of the vibratory signal coming from the bottom part of the web. We support our claim by first building a detailed spider web model, which is tuned by a tension-adjusting algorithm to fit the experimentally observed profiles. Then, the effects of the spider weight and the web tension on the signal transmittance properties are investigated using state-of-the-art finite element analysis tools.

Whole body vibration therapy and diabetes type 2: a systematic review and meta-analysis.

Background: Vibration platforms have demonstrated systemic effects generated by the use of mechanical vibrations, which are similar to those of any physical activity. The effect that whole body vibration (WBV) generates on the organism could be recommended in Diabetes Mellitus 2 (DM 2) patients. Objective: To systematically review and meta-analyze the available evidence on the effects of WBV on glycemic control in patients with DM 2. Material and methods: Exhaustive bibliographic searches were carried out until October 2023 in different biomedical portals and databases: Public Medline (PubMed), Scientific Electronic Library Online (SciELO), VHL Regional Portal, Cochrane Central and Latin American and Caribbean Literature in Health Sciences (LILACS). Randomized clinical trials based on the effects of Whole Body Vibration on glycosylated hemoglobin levels, with control group and participants were non-insulin dependent were the inclusion criteria. Two reviewers extracted data independently. A third reviewer was available for discrepancies. Results: Six articles with 223 participants met the criteria and were included in the systematic review; only four of them met the criteria to be part of the meta-analysis. This meta-analysis reveals a positive and significant effect size (µ ê=0.5731), indicating a substantial difference between the groups studied. Although there is some variability between studies (heterogeneity of 30.05%), the overall direction of the effects is consistent. These findings conclusively suggest the presence of a significant influence of the variable evaluated, underscoring the robustness and consistency of the relationship observed in the literature reviewed. Conclusion: There are no conclusive results due to the lack of data for some variables, which prevents comparison; but WBV may be an effective therapy to improve glycemic control in DM 2 patients. More studies with more patients and longer follow-up are needed.

Design and characteristic analysis of micro multi-core fiber vibration sensor.

We proposed and fabricated a miniaturized multi-core fiber grating vibration sensor. The size of the miniaturized vibration sensor is 10mm × 10mm × 10 mm with a mass of only 0.25g. Finite element analysis and experimental tests were carried out to validate the performance of the vibration sensor. The experiment results indicate that the sensor has a sensitivity of 68.72 pm/g in the X direction and 64.52 pm/g in the Y direction within the operating frequency range of 20-240Hz. The cross-interference between the two directions of vibration measurement falls within 4 %. The sensor is suitable for measuring mechanical vibrations in the mid-low frequency range, especially in cases where size, quality, and distributed measurement are of particular concern.

Label-free spatiotemporal decoding of single-cell fate via acoustic driven 3D tomography.

Label-free three-dimensional imaging plays a crucial role in unraveling the complexities of cellular functions and interactions in biomedical research. Conventional single-cell optical tomography techniques offer affordability and the convenience of bypassing laborious cell labelling protocols. However, these methods are encumbered by restricted illumination scanning ranges on abaxial plane, resulting in the loss of intricate cellular imaging details. The ability to fully control cellular rotation across all angles has emerged as an optimal solution for capturing comprehensive structural details of cells. Here, we introduce a label-free, cost-effective, and readily fabricated contactless acoustic-induced vibration system, specifically designed to enable multi-degree-of-freedom rotation of cells, ultimately attaining stable in-situ rotation. Furthermore, by integrating this system with advanced deep learning technologies, we perform 3D reconstruction and morphological analysis on diverse cell types, thus validating groups of high-precision cell identification. Notably, long-term observation of cells reveals distinct features associated with drug-induced apoptosis in both cancerous and normal cells populations. This methodology, based on deep learning-enabled cell 3D reconstruction, charts a novel trajectory for groups of real-time cellular visualization, offering promising advancements in the realms of drug screening and post-single-cell analysis, thereby addressing potential clinical requisites.

Acoustic, aerodynamic, and vibrational effects of ventricular folds adduction in an ex vivo experiment.

Objectives: The excessive adduction of ventricular folds has been observed in patients with dysphonia and professional singers. Whether these changes in the ventricular folds are the cause or just a result of disease progression remains unclear, and their potential pathological and physiological implications are yet to be determined. This study aimed to examine the impact of different degrees of ventricular adduction on acoustics, aerodynamics, and vocal fold vibration. Methods: The excised models of mild and severe ventricular adduction were established. We recorded the vibration pattern of vocal folds and ventricular folds and measured acoustic metrics, including fundamental frequency (F0), Jitter, Shimmer, harmonic-to-noise ratio (HNR), and sound pressure level (SPL). Furthermore, we evaluated the aerodynamics index through phonation threshold pressure (PTP), phonation instability pressure (PIP), mean flow rate (MFR), phonation threshold flow (PTF), and phonation instability flow (PIF). Results: Irregular vibrations of the ventricular fold were observed during ventricular adduction. Notably, mild and severe ventricular adduction conditions showed a significant increase in PTP, Shimmer, and Jitter, whereas MFR, PIF, and HNR decreased compared with the control condition. Conclusions: Ventricular adduction leads to the deterioration of acoustic and aerodynamic parameters. The aperiodic and irregular vibration of the ventricular folds may be responsible for this phenomenon, although further experiments are warranted. Understanding the functioning of ventricular folds can be beneficial in directing the treatment of muscle tension dysphonia and improving voice training techniques.Level of evidence: level 4.

Vibration-Induced Illusory Movement Task Can Induce Functional Recovery in Patients With Subacute Stroke.

In recent years, mental practice (MP), which involves repetitive motor imagery (MI), has been applied in rehabilitation to actively enhance exercise performance. MP is a method that involves repetitive MI, consciously evoking the intentions and content of the exercise without actual exercise. Combining actual exercise with MP promotes the development of exercise skills. However, it is possible that the MI recall ability differs greatly between individuals, affecting the therapeutic effect. In contrast, the vibration-induced illusory movement (VIM) task acts as a method to induce a motor illusion by somatosensory stimuli without actual motor. VIM, actual movement, and MI are thought to share a common neural basis in the brain. Therefore, it was hypothesized that the VIM task would complement the differences in MI recall in individual patients with hemiplegic stroke and may be a new treatment to enhance MI recall. Accordingly, in this study, we investigated the therapeutic effects of the VIM task in patients with hemiplegic stroke. In Study I, the therapeutic effect of the VIM task in 14 patients with post-stroke hemiplegia was evaluated by motor function assessment. In Study II, treatment effects were investigated by examining the ability of the same group of patients to recall MI and by neurophysiological examination of the electroencephalogram (EEG) during MI recall in four patients who consented to the study. Motor function and MI were assessed four times: before the intervention, after occupational therapy, after the VIM task (which used the motor illusion induced by tendon vibration), and one month after acceptance of therapy. Compared with occupational therapy, the VIM task showed a statistically significant improvement in upper limb function and MI ability. In addition, we found an increase in event-related desynchronization intensity during MI in the affected hemisphere only after the VIM task. It is possible that the VIM task facilitates motor function and MI. VIM task implementation of MI recall variability between individuals, which is a problem in mental practice, possible to increase the effectiveness of the brain-machine interface.

Effectiveness of External Precooling and Vibration Induced by BUZZY on Pain and Anxiety During Inferior Alveolar Nerve Block Injection in Children.

Purpose: Children's fear of the injection of local anesthetic agents affects their cooperation in pediatric dentistry. Different techniques are available to decrease the injection pain, including the use of precooling agents or vibrators. The present study investigated the effectiveness of Buzzy (Buzzy MMJ Labs, Atlanta, GA, USA). This device transfers cold and external vibration to the injection site during the inferior alveolar nerve block (IANB) injection. Materials and Methods: The present self-control, randomized, and double-blind clinical trial evaluated 30 children aged 6-12, who had bilateral mandibular permanent or primary carious molar teeth. On one side, the BUZZY was applied before and during the IANB injection, and the other side was considered as control. On both sides, a topical anesthetic gel was applied before injection. The pain severity and children's anxiety were determined using Wong-Baker, face, leg, activity, cry, consolability (FLACC) scales, and the heart rate. Results: The mean age of the participants was 7.18 ± 1.5 years, with 12 girls and 18 boys. The Wong-Baker scale and FLACC scale did not show any statistically significant difference between BUZZY and control (p value = 0.9 and 0.15, respectively). In addition, BUZZY tool did not significantly decrease pain and anxiety during injection, assessed through the heart rate difference (p=0.38). Conclusion: Under the limitations of the present study, a combination of precooling and vibration using the BUZZY device did not decrease pain and anxiety in children during the IANB injection.

Differences in Somatosensory Function Related to Hand Dominance: Results of a Quantitative Sensory Testing Study in Healthy Volunteers.

Purpose: Quantitative sensory testing commonly utilizes the unaffected, contralateral side as a control to detect somatosensory dysfunction. There is scant evidence that somatosensory function for the volar dominant and non-dominant hands is equivalent, therefore intra-patient comparisons are unwarranted. This study aimed to identify dominance-related differences in palmar hand somatosensation, thereby determining if the unaffected contralateral hand is a valid comparator in clinical populations. Participants and Methods: With ethical approval (IREC_13_1_10) and informed consent, 110 healthy adult volunteers' participated in this clinical measurement study. Somatosensory function was assessed with the German Research Network on Neuropathic Pain (DFNS) quantitative sensory testing (QST) protocol. Half of the participants were tested on the dominant hand. Thirteen parameters of thermal and mechanical detection and pain threshold were evaluated at both the dorsal and volar hand (distal middle finger). Tests were performed in the same order and instructions were read from a standardized script. Results for dorsal hand tests were compared to DFNS normative data to confirm participants met study inclusion criteria. Between-group differences for age and sex were investigated with the independent samples t-test and Chi-square test of independence, respectively. Group differences for dominant and non-dominant hands for all 13 continuous QST parameters were investigated with the Mann-Whitney U-test. Results: Data for 106 participants were included in statistical analysis. Fifty percent of participants were tested on the dominant hand [n=53]; there were no differences for age or sex between groups (dominant or non-dominant hand test group). The dominant volar hand was significantly more sensitive to vibration detection threshold than the non-dominant hand (P=0.001). There were no significant differences related to dominance for other DFNS QST measures. Conclusion: For quantitative sensory testing with the DFNS protocol in healthy cohorts, the contralateral, unaffected hand is a valid control, with the exception of vibration detection threshold.

A roadmap for assessing the diagnostic usefulness of neurosensory testing and an updated method for exposure assessment among vibration-exposed workers in northern Sweden.

Workers who use handheld vibrating machines such as grinders, hammers and chainsaws expose themselves to hand-arm vibration (HAV). Exposure to HAV may cause injuries to both the neurological and the vascular system. The occupational health services (OHS) in Sweden use a formal guideline for secondary prevention focusing on early detection of vibration-related injuries. The guide includes several screening tools, such as a screening questionnaire, clinical examinations, and laboratory tests. There are no studies, to our knowledge, on the diagnostic value of the separate items on symptoms in the screening questionnaire in relation to the laboratory tests or the clinical examinations performed during a medical examination among patients exposed to HAV. Furthermore, the recently presented ISO standard for HAV measurements (ISO/TR 18,750) has only been tested for vascular injuries and not neurological injuries. This research roadmap aims to evaluate separate items in a screening questionnaire on neurological symptoms in relation to laboratory and clinical tests among HAV exposed workers in the Arctic region of Northern Sweden. It also covers a comparison of the dose-response of the current ISO 5349-1 measurement standard and the new suggested standard ISO/TR 18,750 with the neurosensory outcomes. This manuscript describes the study rationale, design, methods, and significance.