Vibration Perception Research Articles

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 It was found that these standards are outdated (old coordinate systems and old values of the coefficients of frequency weighting curves are used).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 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 inter-frequency 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 inter-frequency interval play a significant role on 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 to pure tones perceived intensity.

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 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.

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.

Efficacy and Safety of the Combination of Palmitoylethanolamide, Superoxide Dismutase, Alpha Lipoic Acid, Vitamins B12, B1, B6, E, Mg, Zn and Nicotinamide for 6 Months in People with Diabetic Neuropathy.

To investigate the efficacy of Palmitoylethanolamide (PEA, 300 mg), Superoxide Dismutase (SOD, 70 UI), Alpha Lipoic Acid (ALA, 300 mg), vitamins B6 (1.5 mg), B1 (1.1 mg), B12 (2.5 mcg), E (7.5 mg), nicotinamide (9 mg), and minerals (Mg 30 mg, Zn 2.5 mg) in one tablet in people with Diabetic Neuropathy (DN). In the present pilot study, 73 people (age 63.0 ± 9.9 years, 37 women) with type 2 Diabetes Mellitus (DMT2) (duration 17.5 ± 7.3 years) and DN were randomly assigned to receive either the combination of ten elements (2 tablets/24 h) in the active group (n = 36) or the placebo (n = 37) for 6 months. We used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE), measured vibration perception threshold (VPT) with biothesiometer, and Cardiovascular Autonomic Reflex Tests (CARTs). Nerve function was assessed by DPN Check [sural nerve conduction velocity (SNCV) and amplitude (SNAP)]. Sudomotor function was assessed with SUDOSCAN, which measures electrochemical skin conductance in hands and feet (ESCH and ESCF). Pain score (PS) was assessed with Pain DETECT questionnaire. Quality of life was assessed by questionnaire. In the active group, there was a large improvement of pain (PS from 20.9 to 13.9, p < 0.001). There was also a significant improvement of vitamin B12 (B12) levels, MNSIQ, SNCV, VPT, and ESCF (222.1 vs. 576.3 pg/ mL, p < 0.001; 6.1 vs. 5.9, p = 0.017; 28.8 vs. 30.4, p = 0.001; 32.1 vs. 26.7, p = 0.001; and 72.2 vs. 74.8, p < 0.001 respectively). In the placebo group, neither pain (21.6 vs. 21.7, p = 0.870) or any other aforementioned parameters changed significantly, and MNSIE worsened (2.9 vs. 3.4, p < 0.001). As a result, changes from baseline to follow-up in pain, B12 levels, VPT, and MNSIQ differed significantly between the two groups (p < 0.001, 0.025, 0.009, and <0.001, respectively). CARTs, SNAP, ESCH did not significantly change in either of the two groups. The combination of the ten elements in one tablet for 6 months at a daily dose of two tablets in people with DN significantly improves pain, vibration perception threshold, and B12 levels.

Screening tools for diabetic foot ulcers: a narrative review.

The prevalence of diabetic foot ulcers (DFUs) is 4 to 10% among people with diabetes mellitus. DFUs are associated with increased morbidity and mortality as well as reduced quality of life and have a significant impact on overall healthcare expenditure. The main predisposing factors for DFU are diabetic neuropathy, peripheral arterial disease, and trauma. The fact that a range of tests can be used to identify patients at risk for DFU often causes confusion among practitioners regarding which screening tests should be implemented in clinical practice. Herein we sought to determine whether tests of somatic nerve function, such as pinprick sensation, thermal (cold/hot) test, ankle reflexes, vibration perception, 10-g monofilament, Ipswich touch test, neuropathy disability score, and nerve conduction studies, predict the development of DFUs. In addition, we examined whether sudomotor function screening tests, such as Neuropad, sympathetic skin response, and other tests, such as elevated plantar pressure or temperature measurements, can be used for DFU screening. If not treated properly, DFUs can have serious consequences, including amputation, early detection and treatment are vital for patient outcomes.

"Effect Of Electroacupuncture On Sensory Peripheral Nerve Function In Diabetic Peripheral Neuropathy: A Randomized Controlled Trial Protocol."

Background: Diabetes, a chronic metabolic disorder, affects millions globally, with Type 2 diabetes being the most prevalent. Diabetic Peripheral Neuropathy (DPN) is a common complication, characterized by symptoms such as pain, tingling, and numbness due to peripheral nerve damage. The global burden of diabetes has been rising, particularly in low- and middle-income countries. In India, the number of diabetes cases is projected to reach over 134 million by 2045. Traditional treatments for DPN often have limited efficacy and adverse longterm effects, highlighting the need for alternative therapies. Objective: This study aims to investigate the efficacy of electroacupuncture in improving sensory nerve functions in patients with DPN. Specific acupuncture points will be targeted to assess their impact on vibration perception, hot and cold perception, touch sensitivity, and skin temperature. Methods: A randomized controlled trial will be conducted with 80 participants divided equally into an interventional group and a control group. The interventional group will receive electroacupuncture at specific points (ST44, ST36, ST43, K2, K3, BL60, SP9, and GB41) three times a week for 8 weeks. The control group will continue their usual routine and receive the treatment post-study. Primary outcomes will be measured using the NEURO TOUCH instrument to assess sensory thresholds and skin temperature. Secondary outcomes will include pain assessment using the Visual Analog Scale (VAS). Data will be analyzed using SPSS version 16. Results: The study will evaluate the degree of sensory improvement in peripheral nerves and the effectiveness of electroacupuncture in reducing neuropathic pain. This research seeks to bridge the gap in understanding the mechanisms and efficacy of electroacupuncture in DPN treatment. Conclusion: This study will provide significant insights into the potential benefits of electroacupuncture for DPN, offering an alternative approach to improve the management of this debilitating condition. The findings could inform future clinical practices and guidelines for DPN treatment

"Effect Of Electroacupuncture On Sensory Peripheral Nerve Function In Diabetic Peripheral Neuropathy: A Randomized Controlled Trial Protocol."

Background: Diabetes, a chronic metabolic disorder, affects millions globally, with Type 2 diabetes being the most prevalent. Diabetic Peripheral Neuropathy (DPN) is a common complication, characterized by symptoms such as pain, tingling, and numbness due to peripheral nerve damage. The global burden of diabetes has been rising, particularly in low- and middle-income countries. In India, the number of diabetes cases is projected to reach over 134 million by 2045. Traditional treatments for DPN often have limited efficacy and adverse longterm effects, highlighting the need for alternative therapies. Objective: This study aims to investigate the efficacy of electroacupuncture in improving sensory nerve functions in patients with DPN. Specific acupuncture points will be targeted to assess their impact on vibration perception, hot and cold perception, touch sensitivity, and skin temperature. Methods: A randomized controlled trial will be conducted with 80 participants divided equally into an interventional group and a control group. The interventional group will receive electroacupuncture at specific points (ST44, ST36, ST43, K2, K3, BL60, SP9, and GB41) three times a week for 8 weeks. The control group will continue their usual routine and receive the treatment post-study. Primary outcomes will be measured using the NEURO TOUCH instrument to assess sensory thresholds and skin temperature. Secondary outcomes will include pain assessment using the Visual Analog Scale (VAS). Data will be analyzed using SPSS version 16. Results: The study will evaluate the degree of sensory improvement in peripheral nerves and the effectiveness of electroacupuncture in reducing neuropathic pain. This research seeks to bridge the gap in understanding the mechanisms and efficacy of electroacupuncture in DPN treatment. Conclusion: This study will provide significant insights into the potential benefits of electroacupuncture for DPN, offering an alternative approach to improve the management of this debilitating condition. The findings could inform future clinical practices and guidelines for DPN treatment.

A Study to Evaluate the Effect of Alpha-Lipoic Acid on Neuropathic Symptoms in Diabetic Neuropathy Patients on Gabapentin or Pregabalin.

Introduction Chronic hyperglycemia is a key factor in the development of diabetic peripheral neuropathy (DPN), contributing significantly to the progression of this condition through the induction of oxidative stress. Elevated blood glucose levels lead to increased production of reactive oxygen species (ROS), which cause damage to neuronal cells and exacerbate neuropathic symptoms. Alpha-lipoic acid (ALA) is a potent antioxidant that neutralizes ROS and reduces oxidative damage. By addressing the mechanisms of neuropathy, ALA mitigates the effects of chronic hyperglycemia through antioxidant regeneration, inflammation reduction, and endothelial function improvement. As a result, ALA is emerging as a promising intervention for managing oxidative stress and inflammation in DPN. Methods Prospective, double-blind, placebo-controlled study, a total of 52 DPN subjects on gabapentin or pregabalin were randomly assigned to either ALA 600 mg oral once daily or placebo oral once daily for 12 weeks. Treatment outcome was assessed using vibration perception threshold (VPT), Neuropathy Total Symptom Score 6 (NTSS-6), quality of life (QOL) assessed by 12-Item Short Form Health Survey (SF-12) Questionnaire, oxidative stress biomarkers (malondialdehyde (MDA), nitric oxide (NO), and glutathione (GSH)) and inflammatory biomarker (high-sensitivity C-reactive protein (hs-CRP)) at baseline and every visit (four, eight, and 12 weeks). Neuron-specific enolase (NSE) levels were done at baseline and 12 weeks. Glycated hemoglobin (HbA1C) and safety parameters were done at screening and 12 weeks. Compliance with the study medication was assessed by pill count. Reported adverse drug reactions were recorded. Results A total of 52 subjects (males = 22; females = 30) with a mean age of 55.63 ± 7.5 years were randomized to receive either ALA or placebo. A significant reduction in VPT was observed with ALA at 12 weeks compared to baseline (from 26.92 ± 3.58 to 22.14 ± 1.94; p < 0.0001). Secondary parameters like NTSS-6, QOL by SF-12 questionnaire, NSE levels, oxidative biomarkers levels, and inflammatory biomarkers showed significant improvement with ALA compared to placebo. No serious adverse events were reported. Conclusion ALA demonstrated a protective effect against DPN by its antioxidant and anti-inflammatory effects and was found to have good safety.

Assessment of small nerve fiber function as an early marker of peripheral neuropathy in children and adolescents with type 1 diabetes mellitus (T1DM).

This study aimed to assess subclinical peripheral diabetic neuropathy (PDN) in adolescents with type 1 diabetes mellitus (T1DM). Subjects included 53 T1DM patients (age (mean ± SE): 15.8 ± 0.54 years, disease duration: 6.0 ± 0.51 years and HbA1c: 7.9 ± 0.19%), and 37 healthy gender matched controls (age: 15.6 ± 0.52 years). PDN was assessed by vibration perception threshold (VPT) and by quantitative sensory testing (QST). In controls, 95% confidence intervals were calculated. Among patients, VPT prevalence of abnormality ranged from 60-73.4% on different sites. Higher VPT was found in patients on all examined sites (p < 0.01). In controls, VPT correlated with height (r = 0.48, p = 0.05). Regarding QST prevalence of abnormality, cold detection threshold (CDT) ranged 7.3-39.0%, cold pain threshold (CPT) ranged 22.22-29.63%, hot detection threshold (HDT) ranged 34.14-63.41%, and hot pain threshold (HPT) ranged 15.79-36.84%. In patients, CPT correlated with BMI (r = 0.42, p = 0.05) and diabetes duration, (r = 0.40, p = 0.05), HPT correlated with age (r = 0.36, p = 0.05) and height (r = 0.35, p = 0.05), while in controls with BMI (r = 0.51, p = 0.05). No correlation of VPT or QST with HbA1c was observed. Adolescents with T1DM in this study, although asymptomatic, showed a high prevalence of impaired indices of PDN, highlighting potential clinical implications of early identification of PDN.

Serum levels of biomarkers related to severity staging of Raynaud’s phenomenon, neurosensory manifestations, and vibration exposure in patients with hand-arm vibration injury

Our aim was to explore possible relationships between serum levels of biomarkers in patients with hand-arm vibration injury in relation to the severity of the vascular, i.e., Raynaud’s phenomenon (RP), and neurosensory manifestations, the current exposure level, and the duration of exposure. This study was of case series design and involved 92 patients diagnosed with hand-arm vibration injury. Jonckheere’s trend test was used to assess any association between serum levels of biomarkers and RP as well as neurosensory manifestations, graded by the International Consensus Criteria. Generalized linear models with adjustment for possible confounders were also used for associations between serum levels of biomarkers and; (1) severity of RP recorded as the extent of finger blanching calculated with Griffin score, (2) vibration perception thresholds, (3) magnitude of current exposure as [A(8); (m/s2)] value, and (4) the duration of exposure in years. Serum levels of thrombomodulin, von Willebrand factor, calcitonin gene related peptide (CGRP), heat shock protein 27, and caspase-3 were positively associated with severity of RP. Serum levels of CGRP were positively associated with the neurosensory component. No associations with exposure were shown for these biomarkers. For Intercellular adhesion molecule 1 and monocyte chemoattractant protein 1, no associations were found with neither severity nor exposure. Levels of serum biomarkers associated with endothelial injury or dysfunction, inflammation, vasodilation, neuroprotection, and apoptosis were positively associated with the severity of hand-arm vibration injury.

Cooperation mechanism between the vacuum levels and interface dipole energy of triboelectric materials for real-time vibration recognition

Triboelectric Nanogenerator (TENG) device, acting as sensors of energy harvesting and material identification, are attracting intensive attention. Nevertheless, vibration wave recognition cannot be achieved by the developed devices owing to device structure and working mechanism limitations. Here, a cooperation mechanism between the vacuum level and interface dipole energy of triboelectric materials is proposed to explore triboelectric charge generation and migration. Hence, metallized cottons of high specific surface area encapsulated by polydimethylsiloxane (PDMS) of low elastic modulus are developed as TENG-based sensors to realize vibration recognition. The results indicate electrons flow from PDMS to metallized cotton with the generation of an extremely thin interfacial dipole barrier layer because the vacuum level of metallized cotton is higher than that of PDMS, resulting in the accumulation of triboelectric charges on the PDMS surface under vibration, further leading to generating distinct triboelectric signals that can be simply differentiated using signal amplitude or peak shape with 98.3 % recognition accuracy for vibration waveform. Besides, combined with the deep machine learning and triboelectric effect, a vibration perception system integrated with a TENG-based sensor, data processing and display modules is also developed for real-time vibration monitoring. This work contributes to further clarifying the theoretical mechanisms of triboelectric charge excitation under vibration.

416 The Impact of Pancreas Transplantation on Secondary Diabetic Complications: A Systematic Review

Abstract Aim Pancreas transplantation (PT) provides diabetic cure for patients with complicated Type 1 Diabetes Mellitus (T1DM). We aimed to examine the impact of PT on secondary diabetic complications, including retinopathy, neuropathy, and cardiovascular disease. Method A database search using MedLINE for publications up to April 2023 was conducted employing MeSH terms ‘Pancreas Transplantation’ AND ‘Diabetes Mellitus, Type 1’ AND ‘Diabetic Retinopathy’ OR ‘Heart Disease’ OR ‘Cardiovascular Diseases’ OR ‘Peripheral Vascular Disease’ OR “Amputation’ OR ‘Neuropathy.” Results 223 articles were screened, with 172 excluded as per study design (total included 51). 64.7% (n=33) of studies were retrospective case control studies, 35.3% (n=18) of studies were retrospective cohort studies. A total of 5616 patients with a mean of 99.1 (SD± 262.4) simultaneous kidney transplant (SPK) patients and 48.2 (SD± 262.4) pancreas transplant alone (PTA) patients per article were studied. All articles examining diabetic retinopathy concluded that retinopathy improved or stabilized. 69% (n=11) of papers demonstrated no significant change to visual acuity. An equal number of articles (n=4) demonstrated increased peripheral nerve conduction velocity after SPK and PTA. 40% (n=2) of articles examining vibration perception studies demonstrated an increase post-transplantation. Improvements in cardiac events incidence, metabolic factors, and heart structure were seen in 79% (n=15) of cardiovascular articles. Conclusions Despite significant heterogeneity in outcome measures observed, PT provides benefits in mitigating the complication profile of T1DM. Standardised outcome measurement should be adopted to allow assessment of the impact of beta-cell replacement with the potential for objective evidence reversibility of secondary complications.