Vibration Perception Research Articles

Burden of diabetic peripheral neuropathy in a rural demography of India is revealed by biothesiometry: a reliable screening tool

Background: Diabetes mellitus (DM) is the most prevalent non-communicable disease in the world estimated to be 4.4% in 2030 globally. Among its complications, diabetic peripheral neuropathy (DPN) is the common disorder manifested as ‘glove and stocking sensation’ in the lower extremities. Aim to study the prevalence and to grade DPN in patients attending OPD. Methods: Patients coming to the general surgery and plastic surgery outpatient department were selected. A total of 331 patients will be asked history by a simple questionnaire and symptoms are graded by modified neuropathy symptom score (MNSS) and clinical examination are done and graded by diabetic neuropathy examination (DNE) and vibration perception threshold (VPT) is measured by biothesiometry. Results: Among the DPN patients, 57.40% are asymptomatic and 12.08% are having severe symptoms by MNDS score and about 27.49% having increased risk for pronation for foot ulcer by DNE score and about 43.2% having risk for foot ulcer by biothesiometry average from the most common site for loss of sensation involving over 1st, 3rd, 5th metatarsal head to the least involved site as midfoot. Conclusions: This study reveals the impact of DPN in a rural area, so by implementing this type of screening method reduces the development of foot ulcers by about 60% in asymptomatic patients and leg amputations by 85% in patients with severe stage of DPN with proper foot care.

A Chronological Review of the Transmission and Effects of Mechanical Vibrations on the Hand—Arm System in an Occupational Workplace

This paper aims to review researchers’ concerns over time (from the 1980s to the present) regarding the transmission of mechanical vibrations in the workplace to the limbs, with a preponderant focus on the hand–arm system and some of the effects over time. These concerns are strictly approached from the point of view of their effects on different races, types of jobs, and forms of tools handled in the workplace. In this regard, when we refer to unwanted vibrations (harmful to a person) in the industrial environment, these are vibrations that can produce harmful effects on an individual’s health, leading to occupational diseases such as white finger syndrome. Some of the terms specific to the studies reviewed, such as vibration perception and biodynamic force, among others, are explained in this paper as needed. Studies in the field have shown that vibrations are transmitted differently when the arm is bent at the elbow joint compared to when it is outstretched; also, the transmission of vibrations is influenced by other factors, such as the temperature of the working environment, the gender and age of the person who is using the vibrating devices, and last but not least, the time of their use and the frequency. The conclusions presented by the specialized literature often refer to existing standards, in particular SR EN ISO 5349/2003. Finally, in this paper, conclusions are drawn regarding how to analyze the transmission of vibrations over time, and some recommendations are given for avoiding or minimizing them, which can be added to the already-existing standards.

How to determine hands’ vibration perception thresholds – a systematic review

The vibration perception threshold (VPT) is the minimum amplitude required for conscious vibration perception. VPT assessments are essential in medical diagnostics, safety, and human–machine interaction technologies. However, factors like age, health conditions, and external variables affect VPTs. Various methodologies and distinct procedures have been used to access VPTs, leading to challenges in establishing standardized protocols. Following the PRISMA methodology, this systematic review was conducted to answer the research question: “How are vibration perception thresholds assessed on the glabrous skin of the hands and fingers of healthy humans?” Searches were conducted across five databases to locate recent studies reporting data from VPT assessments, published in English, between 2012 and 2023. Thirty-nine studies met the inclusion criteria. Data on study goals and various methodological aspects was categorized and analyzed. Information gaps were identified, and this review offers recommendations for future studies to enhance standardization and facilitate data comparison. This review also suggests directions for future research, aiming to improve our understanding of how humans perceive haptic information.

Vibrotactile perception depends on cognition not just peripheral nerve integrity: a cross-sectional study

Background: Vibration perception is often considered a peripheral nerve and dorsal column function, without considering the role of cognition. The current study tested cognition’s role in vibrotactile perception thresholds (VPT). Methods: We recruited cases with mild-moderate dementia or mild cognitive impairment thought to reflect probable Alzheimer’s pathology (AD/MCI group), and controls without memory concerns (all participants >50 years). Polyneuropathy, B12 deficiency, diabetes, or other conditions associated with cognitive impairment were exclusionary criteria. Participants underwent cognitive evaluation with the Self-Administered Gerocognitive Examination (SAGE), standardized nerve conduction studies, and quantitative VPT testing. Demographic and medical history were obtained through interview and chart review. We constructed linear regression models to test whether poor cognition correlates with VPT. Results: Nineteen AD/MCI participants (age 71.5±8.9, 47.4% female) and fourteen controls (age 67.4±9.3, 78.6% female) did not differ on age or gender. Univariate predictors of poor/increased mean VPT (all p­-values <0.10) were age, AD/MCI, SAGE score, sural sensory nerve action potential (SNAP) amplitude <5 microvolts, yearly income <$50,000, history of vascular disease, and peroneal motor and sural conduction velocity (CV). SAGE score (standardized β=-0.38, p<0.01); sural SNAP amplitude (β=0.51, p<0.001); peroneal motor CV (β=-0.37, p<0.01), history of vascular disease (β=0.27, p=0.03), and female gender (β=0.22, p=0.10) remained independently associated with VPT in multivariable linear regression analysis (backwards modeling; removal criteria p>0.10; model adjusted R2=0.66; p<0.001). Conclusions: Poor cognition is associated with worsened VPT. Neurologists should consider cognition when using sensory perception to assess peripheral nerve integrity, both for research and during a traditional neurologic examination.

Improving Perception Threshold Tracking for Rapid Evaluation of Diabetic Peripheral Neuropathy.

Accurate assessment of diabetic peripheral neuropathy (DPN) is essential to prevent further complications, yet current methods have limitations. Perception threshold tracking (PTT) offers promise as a novel approach for rapid evaluation of both large and small fiber dysfunction. To enhance efficiency, this study explores the Psi method compared to the Method of Limits (MoL) in estimating perception thresholds. The aim is to assess agreement, uncertainty, and the number of stimuli required for adequate estimation by each method. Forty-three participants with diabetes underwent an estimated sural nerve conduction study, quantitative sensory testing, vibration perception threshold testing, and PTT. PTT utilized both patch and pin electrode configurations to activate large and small fibers, respectively. The uncertainty of perception thresholds was estimated as the inverse slope of the psychometric functions. Perception thresholds were significantly higher for the patch electrode (2.5 [2.1-3.0] mA) compared to the pin electrode (0.71 [0.56-0.91] mA; rmANOVA, p < 0.001). Bland-Altman analysis revealed a non-significant 3.3% bias between the methods, but wide limits of agreement (-42%-84%). Uncertainty was lower for the Psi method (0.80 [0.58;1.11] mA) compared to MoL (2.0 [1.2;2.9] mA; rmANOVA, p < 0.005). The Psi method achieved acceptable perception threshold estimation with only 30 stimuli. At the group level, the MoL and Psi methods produced similar perception thresholds. However, the Psi method required fewer stimuli and yielded less uncertainty in perception threshold estimation compared to MoL. Future studies should prioritize the Psi method for its efficiency and reliability.

A Comparative Analysis of Diagnostic Accuracy: Vibration Perception Threshold vs. Diabetic Neuropathy Examination for Diabetic Neuropathy

ABSTRACT Background: Diabetes mellitus has emerged as a global health crisis, with its prevalence escalating dramatically. Diabetic peripheral neuropathy (DPN) stands out as one of the most frequent complications, leading to significant morbidity, including foot ulcers and amputations, if not identified and managed promptly. Effective screening methods are essential for early detection, which can significantly improve patient outcomes and reduce the risk of severe complications. Aim and Objectives: This study aims to evaluate the sensitivity and specificity of the Diabetic Neuropathy Examination (DNE) score in comparison to the vibration perception threshold (VPT) test. Both methods will be assessed individually and in combination to determine their effectiveness in diagnosing DPN among patients with diabetes. The study also seeks to establish a correlation between these screening tests. Materials and Methods: A case-control study was conducted involving 100 subjects, comprising 50 patients diagnosed with DPN and 50 healthy controls. The participants were aged between 30 and 70 years, and various parameters such as fasting blood sugar, anthropometric measurements, DNE scores, and VPT readings were recorded. Ethical clearance was obtained, and informed consent was secured from all participants. Results: The findings indicated that the DNE score demonstrated a sensitivity of 80% and a specificity of 73.33%, while VPT exhibited a sensitivity of 70% and a specificity of 86.67%. When both tests were combined, the sensitivity increased to 90%, highlighting the potential for enhanced diagnostic accuracy through a multimodal approach. Conclusion: The DNE score, when utilized alongside VPT, provides a robust framework for the early detection of DPN, particularly in community settings where resources may be limited. This study underscores the importance of integrating simple, effective screening techniques into routine clinical practice to mitigate the risks associated with diabetic complications.

A Study Protocol on the Evaluation of Comparative Efficacy of Waj (Acorus calamus Linn.) versus Pregabalin in Diabetic Peripheral Neuropathy

Background: Diabetes is a major global health concern in the twenty-first century. The International Diabetes Federation (IDF) estimates that by the end of 2021, complications from diabetes would have killed 747,000 peoples in India. Diabetic peripheral neuropathy (DPN) is a disorder that develops in patients with diabetes (type 1 and type 2) and is not attributable to any other peripheral neuropathy causes. Clinically, it may manifest as burning, tingling, numbness, or neuropathic pain in the foot that tends to get worse at night. DPN frequently results in ulceration, infection, deterioration of the skin, and ultimately amputation. Methods: This study will be conducted as randomized standard-controlled, single-blind trial on 150 DPN subjects with type 2 diabetes by randomly assigned them to two groups (test or standard), where test group will receive two capsules twice (containing 500 mg powder of test drug in each capsule) with water and control group will receive one capsule of pregabalin 75 mg twice. Both groups will be treated for 60 days with 30 days post treatment follow-up addition to their regular anti-diabetic treatment. The subjective parameters of burning, tingling, and pain in the feet will be evaluated every two weeks using the visual analog scale (VAS) and arbitrary scale. Objective parameters, Toronto Clinical Scoring System (TCSS) will be assessed fortnightly along with vibratory perception threshold (VPT), assessed pre and post-treatment. Data will be assessed statistically with appropriate tests.

Using biothesiometer, Neuropathy Symptom Score, and Neuropathy Disability Score for the early detection of peripheral neuropathy: A cross-sectional study.

Patients with peripheral neuropathy could have damaged peripheral nerves, which leads to sensory and motor dysfunction. Diabetes, infections, and trauma are the major causes of peripheral neuropathy. Vibratory perception threshold (VPT) tools are commonly used to detect peripheral neuropathy. This study aims to determine the assessment of peripheral neuropathy through the different diagnostic tools in the community in Malaysia. A total number of 1283 participants were recruited from the seven retail pharmacies located in Selangor, Malaysia. The peripheral neuropathy test was conducted based on VPT tools on both feet using the digital biothesiometer. Following that, Neurological Symptom Score (NSS) and Neurological Disability Score (NDS) were taken from the participants to assess the neurological symptoms. Participants had an average age of 40.6 ± 12.9 years and were mostly of Chinese ethnicity (54.1%). The findings show that increasing age was associated with more severe peripheral neuropathy across the various assessment tools, but gender differences were found with the biothesiometer test and ethnicity has severity in the biothesiometer and disability scores. The sensitivity and specificity of the biothesiometer test were 0.63 and 0.84, respectively. The combined tool NSS and NDS had high specificity and a high positive predictive value, suggesting that it could be a reliable indicator of peripheral neuropathy when both scores are elevated. The findings show that the biothesiometer test, NSS, and NDS are considered screening VPT tools for diagnosing peripheral neuropathy. However, further evaluation and diagnostic testing are necessary in cases of a positive test result.

Вібрація в будинках, вимоги до допустимих рівнів та критерії оцінки

Objective. The purpose of the study is to determine the current requirements for vibration regulation in buildings. Object and methods of the study. Standards: ISO 2631-1:1997; ISO 2631-2: 2003; DSTU ISO 2631-1:2004; DSTU ISO 2631-2: 2004; BS 6472-1:2008; ONORM S 9012:2010 (Austria); DIN 4150-2:1999 (Germany); UNI 9614:1990 (Italy); Japan: Vibration Control Law; SBR Richtli - Deel B 2002 (Netherlands); NS 8176:2005 (Norway); Real Decreto 1307/2007 (Spain); SS 4604861:1992 (Sweden); FRA (2005), FTA, 2006 (USA). Research results and discussion. The main parameters of vibration, thresholds of sensitivity and comfort, vibration evaluation criteria (VDV, eVDV), directions of action of general vibration, frequency weighting curves (Wb, Wd, Wm), the probability of complaints at different values of vibration acceleration, desirable and maximum weighted average values of vibration acceleration for continuous and impulsive vibration in buildings were analyzed. The current DSTUs on vibration in buildings in Ukraine are analyzed. It was found that these standards are outdated (old coordinate systems and old values of the coefficients of frequency weighting curves are used). It was found that there are no standards for permissible levels or values of vibration in buildings for humans in Ukraine. Conclusions. As a result of the analysis of the considered standards, it was found that the main parameters of vibration are: vibration displacement, vibration velocity; vibration acceleration. Vibration acceleration is most often used. Vibration perception thresholds are not consistent with existing standards, which use frequency weighting factors that do not sufficiently take into account human sensitivity. In different countries, limit value criteria are set above the perception thresholds. Some of them are derived from the threshold irritation level. Vibration criteria are based on maximum and average values. The former are more related to sleep disturbance, the latter are more related to irritation. Keywords. Vibration, standards, vibration criteria, vibration perception thresholds.

Contribution of remote Pacinian corpuscles to flutter-range frequency discrimination in humans

Among the various classes of fast-adapting (FA) tactile afferents found in hairy and glabrous skin, FA2 afferents, associated with Pacinian corpuscles (PC), preferentially signal high-frequency sinusoidal events corresponding with vibration percepts, in contrast to other classes associated with lower frequency flutter percepts. The FA2-PC complex is also uniquely sensitive to distant sources of vibration mechanically transmitted through anatomical structures. In the present study, we used a pulsatile waveform to assess the contribution of FA2 afferents to the perception of flutter-range frequency stimuli (~ 20 Hz) in combination with two methods to abolish local FA inputs and force a dependence on FA2 via transmission from adjacent structures. Firstly, we examined frequency discrimination and perception of vibration applied to the hairy skin overlying the ulnar styloid before and during the blockade of intradermal receptors by local anaesthesia. Secondly, we tested frequency discrimination on the digital glabrous skin before and during the blockade of myelinated fibres by ulnar nerve compression. Despite reliance on vibration transmission to activate remote PCs, we found that flutter-range frequency discrimination was unimpeded across both skin types. Comparisons with stimuli applied to the contralateral side also indicated that perceived frequency was unaffected. This confirms that flutter-range frequency perception can be encoded by the FA2-PC system. Our results demonstrate that input from receptors specialised for low-frequency signalling is not mandatory for flutter-range frequency perception. This explains how the constancy of frequency perception might be achieved across different skin regions, irrespective of the afferent type activated for transmitting these signals.

Effectiveness of a web-based foot-ankle exercise program for treating ulcer risk factors in diabetic neuropathy in a randomized controlled trial

The need for strategies to prevent complications from diabetic neuropathy (DPN) is well recognized. However, foot-ankle exercise programs show weak to moderate evidence, and barriers to their implementation persist, including broad and facilitated access to exercise programs, which guarantee for equity. In this paper, we report for the first time the effectiveness of a web-based foot-ankle exercise program aiming to improve DPN-related outcomes, gait biomechanics and functional outcomes. Sixty-two participants with DPN were randomly allocated into the control group (CG; n = 31), which received the usual care, or the intervention group (IG; n = 31), which received the usual care plus a 12-week foot-ankle exercise program using a web-based software (the SOPeD software). The primary outcomes, DPN symptoms and severity, were assessed using the Brazilian version of the Michigan Neuropathy Screening Instrument and the Decision Support System for Classification of Diabetic Polyneuropathy, respectively. Secondary outcomes included tactile sensitivity (monofilaments) and vibration perception (tuning fork), functional outcomes, such as foot pain and function (Foot Health Status Questionnaire), foot muscle strength and plantar pressure during gait (emed plate), and foot-ankle kinematics and kinetics during gait. Outcomes were assessed at baseline, 12 and 24 weeks by an assessor blinded to group allocation. DPN symptoms and severity remained unchanged after the web-based foot-ankle program. However, IG showed improvements compared to CG, with greater functional reach at 12 weeks, better foot function, reduced foot pain and greater plantarflexion degree during push-off at 24 weeks. Regarding plantar loading during gait, the forefoot pressure reduced in the IG at 12 weeks compared to baseline, but at 24 weeks, forefoot load increased in the IG compared to CG. The 12-week web-based foot-ankle exercise program was feasible, acceptable, demonstrating safety with minimal adverse events, such as delayed onset muscle soreness and foot muscle cramping. While DPN-related outcomes were unaffected by the 12-week SOPeD program, modest improvements in foot pain and function, functional reach, and changes in plantar pressure and plantarflexion degree during gait were noted, mostly at 24 weeks.Trial registration: ClinicalTrials.gov, NCT04011267. Registered on 8 July 2019.

Tactile sensitivity to missing tones in complex vibrotactile signals.

Haptic interactions with objects induce complex vibrotactile signals that are central to tactile perception. Despite the broad literature on vibrotactile perception, surprisingly little is known about the sensory processing of complex tactile signals made of multiple pure tones. To fill this gap, the study reported here investigated the impact of the constitutive pure tones of a complex vibrotactile signal on its perception. Participants completed a three-alternative forced choice (3-AFC) task in which they were asked to identify an odd signal among two complex references. The odd signal was created by removing one pure tone from the reference, which varied in spectral composition, harmonicity, and interfrequency intervals. Each reference signal was made of either two, three, or four pure tones. The results revealed that the removed pure tone's value as well as the interfrequency interval play a significant role in participants' performance whereas changes in harmonicity and complexity have little impact. The smaller the ratio between the removed frequency and the lowest one of the reference signals, the better the participants' capacity to identify the signal with the missing tone. As this ratio correlates with that of pure tone's perceived intensity, participants' performance can be linked to either of them. Analysis of a subset of complex signals made of pure tones perceived with roughly equal intensity showed that the correlation still holds but slightly decreases. Overall, these results suggest that perception of complex vibrations might be mediated by tactile mechanisms related to both frequency selectivity and pure tones' perceived intensity.NEW & NOTEWORTHY This research investigates the respective roles of frequency range, harmonicity, and complexity on human perception of vibrotactile signals. The results revealed that only pure tones that are close to the lower frequencies of the complex vibration are noticed when they are missing. This finding sheds new light on the mechanisms underlying the tactile perception of complex vibrations.

Clinical Cues for the Early Diagnosis of Transthyretin-Related Polyneuropathy.

The estimated prevalence of hereditary transthyretin-related familial amyloid polyneuropathy (TTR-FAP) and the small number of known patients in Germany indicate that many patients with TTR-FAP remain undiagnosed, and may instead be classified as "idiopathic." The aim of this study was to identify biomarkers for detecting TTR-FAP among a cohort of patients with idiopathic polyneuropathy (PNP). Clinical evaluations (including the Neuropathy Impairment Score and Neuropathy Disability Score), nerve conduction studies (NCSs), quantitative sensory testing, and autonomic function tests were performed on 23 patients with TTR-FAP and 89 with idiopathic PNP. Discriminant analysis was then performed to identify variables useful for predicting TTR-FAP. Patients with TTR-FAP had paresis of the finger and thumb muscles, and reduced vibration perception and increased pressure pain in the upper and lower extremities. The NCSs showed that action potentials were smaller in the median, ulnar (both motor and sensory), and sural nerves in TTR-FAP. The sensory nerve conduction velocity was also reduced in the ulnar nerve. Autonomic neuropathy was confirmed by reduced sympathetic skin responses in the hands and feet in TTR-FAP. Multivariate discriminant analysis revealed that finger abduction strength, sensory ulnar nerve action potential amplitude, and vibration detection and pressure pain thresholds in the upper extremities were sufficient to correctly identify TTR-FAP in 81.3% of cases. Detailed clinical and neurophysiological investigations of standard parameters in the upper limb may help to identify the otherwise-rare TTR-FAP.

Glucose-lowering medication associated with weight loss may limit the progression of diabetic neuropathy in type 2 diabetes.

Obesity is a major risk factor for diabetic peripheral neuropathy (DPN) in type 2 diabetes (T2D). This study investigated the effect of glucose lowering medication associated with weight change on DPN. Participants with T2D were grouped based on whether their glucose lowering medications were associated with weight gain (WG) or weight loss (WL). They underwent clinical, metabolic testing and assessment of neuropathic symptoms, vibration perception threshold (VPT), sudomotor function and corneal confocal microscopy (CCM) at baseline and follow-up between 4 and 7 years. Of 76 participants, 69.7% were on glucose lowering medication associated with WG, and 30.3% were on glucose lowering medication associated with WL. At baseline, participants in the WG group had a significantly longer duration of diabetes (p < .01), higher douleur neuropathique en 4 (DN4) score (p < .0001) and VPT (p = .01) compared with those in the WL group. Over a 56-month period, participants in the WG group showed no significant change in body weight (p = .11), HbA1c (p = .18), triglycerides (p = .42), DN4 (p = .11), VPT (p = .15) or Sudoscan (p = .43), but showed a decline in corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD) and corneal nerve fiber length (CNFL) (p < .0001). Participants in the WL group showed a reduction in weight (p = .01) and triglycerides (p < .05), no change in DN4 (p = .30), VPT (p = .31) or Sudoscan (p = .17) and a decline in the corneal nerve branch density (p < .01). Participants treated with glucose lowering medication associated with weight gain had worse neuropathy and greater loss of corneal nerves during follow-up, compared to patients treated with medication associated with weight loss.

Corneal nerve loss in adolescents with obesity and acanthosis nigricans.

Obesity and related metabolic abnormalities in adults are associated with peripheral neuropathy. Acanthosis nigricans (AN) is associated with insulin resistance, fatty liver, hyperlipidemia and glucose intolerance, all of which are risk factors for neuropathy. The aim of this study was to investigate if obese adolescents with AN have evidence of small nerve fiber damage. Adolescents with obesity with and without AN underwent body composition analysis, assessment of vibration perception threshold (VPT), monofilament sensitivity and corneal confocal microscopy (CCM) to quantify corneal nerve fiber density (CNFD), branch density (CNBD), length (CNFL) and inferior whorl length (IWL). Forty-six participants with obesity with (n = 31) and without (n = 15) AN aged 15(14-17) years were compared to 20 healthy controls aged 13(12-14) years. There was no difference in VPT, monofilament sensitivity and CCM measures between adolescents with obesity and controls. However, adolescents with AN had a significantly higher weight (P = 0.022), fat% (P = 0.029) and fat-muscle ratio (P = 0.012) with a lower CNFD (P = 0.045) compared to those with obesity without AN. Adolescents with obesity and acanthosis nigricans have a higher fat mass and small nerve fibre loss, indicative of a sub-clinical neuropathy.

Hand’s Vibration Perception Thresholds—A Systematic Review

The term vibration perception threshold (VPT) refers to the minimum amplitude required for a vibration to be consciously perceived. Knowledge of VPTs can be used to aid in the diagnosis of various pathologies, or to support design decisions during human-machine interface development. However, several factors affect VPT measurements (e.g., contactor size and pressure), thus, comparing VPT results from multiple studies should not be done without considering both the similarities and differences between said studies. This paper presents a systematic review on VPT results obtained across multiple studies, taking into consideration the different factors affecting the values reported in the literature. We intended to answer the following question: “What are the Vibration Perception Thresholds assessed on the glabrous skin of the hands and fingers of healthy humans?” To the best of our knowledge, this is the first attempt at conducting a systematic review focused specifically on numerical VPT results. Starting from 936 records, VPT results from 37 studies were organized according to various factors (gender, age, probe size, contact pressure, psychophysical method, room temperature, skin temperature, and hand location). This data was organized into a table, the Organization Table that is available for readers. This review can help future researchers and developers working on or working with the topic of human perception of vibrations by examining the factors that affect VPTs and discussing strategies to address them. We offer recommendations for future research and insights on how design engineers can utilize VPTs in the development of new haptic devices.

Research on Human Exposure to Transport-Induced Vibration in Buildings

The analysis of human perception of vibrations in buildings is a critical aspect of structural engineering, particularly as urbanization intensifies and the proximity of vibration sources to buildings increases. This paper addresses the frequent errors in the assessment and diagnosis of the impact of vibrations on building occupants. Despite stringent standards and detailed methodologies, misinterpretations and incorrect implementations of these guidelines are common, leading to flawed diagnostic studies. These errors often stem from the misuse of measurement equipment, inappropriate selection of measurement points, and a general lack of comprehensive education on vibration analysis. National guidelines, although largely based on ISO standards, vary significantly, contributing to inconsistent practices across Europe. The dominant sources of urban vibrations include vehicle traffic, particularly heavy trucks and rail vehicles, which significantly impact both building structures and human comfort. This paper reviews the methodologies for measuring and interpreting vibrations, emphasizing the importance of correct sensor placement and data analysis. It highlights the necessity of integrating vibrational comfort into building design, considering both external and internal vibration sources. The study also explores the effectiveness of different evaluation methods, such as the RMS and VDV methods, and the impact of various weighting functions on the analysis results. The findings underscore the need for improved education and standardization in the field to ensure accurate assessments and enhance the vibrational comfort of building occupants.

The high/low frequency balance drives tactile perception of noisy vibrations.

Noisy vibrotactile signals transmitted during tactile explorations of an object provide precious information on the nature of its surface. Understanding the link between signal properties and how they are interpreted by the tactile sensory system remains challenging. In this paper, we investigated human perception of broadband, stationary vibrations recorded during exploration of textures and reproduced using a vibrotactile actuator. Since intensity is a well-established perceptual attribute, we here focused on the relevance of the spectral content. The stimuli were first equalized in perceived intensity and subsequently used to identify the most salient spectral features using dissimilarity estimations between pairs of successive vibration. Based on dimensionally reduced spectral representations, models of dissimilarity ratings showed that the balance between low and high frequencies was the most important cue. Formal validation of this result was achieved through a Mushra experiment, in which participants assessed the fidelity of resynthesized vibrations with various distorted frequency balances. These findings offer valuable insights into human vibrotactile perception and establish a computational framework for analyzing vibrations as humans do. Moreover, they pave the way for signal synthesis and compression based on sparse representations, holding significance for applications involving complex vibratory feedback.

A Comparative Analysis of Smartphone and Standard Tools for Touch Perception Assessment Across Multiple Body Sites.

Tactile perception plays an important role in activities of daily living, and it can be impaired in individuals with certain medical conditions. The most common tools used to assess tactile sensation, the Semmes-Weinstein monofilaments and the 128 Hz tuning fork, have poor repeatability and resolution. Long term, we aim to provide a repeatable, high-resolution testing platform that can be used to assess vibrotactile perception through smartphones without the need for an experimenter to be present to conduct the test. We present a smartphone-based vibration perception measurement platform and compare its performance to measurements from standard monofilament and tuning fork tests. We conducted a user study with 36 healthy adults in which we tested each tool on the hand, wrist, and foot, to assess how well our smartphone-based vibration perception thresholds (VPTs) detect known trends obtained from standard tests. The smartphone platform detected statistically significant changes in VPT between the index finger and foot and also between the feet of younger adults and older adults. Our smartphone-based VPT had a moderate correlation to tuning fork-based VPT. Our overarching objective is to develop an accessible smartphone-based platform that can eventually be used to measure disease progression and regression.

The Role of a Biothesiometer in Early Detection and Management of Diabetic Neuropathy.

Diabetic foot ulcers (DFUs)have become a common and serious outcome of diabetes mellitus (DM). Diabetic peripheral neuropathy (DPN) is often underdiagnosed, which impairs the capacity to prevent foot ulceration. The clinical manifestations typically include sensory complaints, which leavepatients vulnerable to increased risk of injury without their awareness. The current study aims to assess the viability of VPT (vibration perception threshold) testing using a biothesiometer as an early diagnostic tool for detecting diabetic neuropathy and reducing the burden of diabetic foot disease. This prospective study was conducted in Dr. D. Y. Patil Medical College, Pimpri, Pune from August 2022 to July 2024 among 50 patients with DFUs. Ethical approval was taken from the Institutional Ethical Committee. An informed consent was obtained from all the study participants. VPT testing using a biothesiometer was done to assess the neurological status of the patient's limbs. A significant difference between the symptomatic and asymptomatic cases was also calculated to evaluate the co-relation of symptoms compared to VPT. The largest age group among those surveyed is 41-50 with a mean age of 50.72. Males form a slightly larger proportionthan females. A total of 22 (44%) ulcers are present over the plantar aspect of the foot. Out of the entire study, 37 (74%)individuals reported Grade II or III neuropathy, and 29 (58%)individuals reported no symptoms of diabetic neuropathy. The majority portion ofindividuals in the study had an HbA1c ranging from 6.5% to 8%. After an intervention, 44 (88%) patients did not experience a change in their VPT grading after six months. The chi-square test results suggest that the onset period of diabetes in years or the type of treatment history for diabetes does not significantly influence VPT grading among the surveyed individuals. However, individuals with higher HbA1c levels tend to exhibit more severe VPT impairments. Regular monitoring of VPT grading is crucial for early diagnosis of neuropathy, tracking disease progression, and assessing intervention effectiveness. Hence, we recommend all diabetic patientsregularly undergo biothesiometry as part of their routine diabetic check-ups to help prevent disease progressionand complications like amputations and improve their overall quality of life.