Vibration Threshold Research Articles

568-P: Pain Threshold of Intraepidermal Nerve Terminal Reflects Small Nerve Fiber Function and Rises in Early Phase of Diabetes

We measured pain threshold of intra-epidermal nerve terminal (PINT) which is a simple and noninvasive method that can measure pain threshold of A delta fiber by intra-epidermal electrical stimulation. We aimed to investigate normal value, prevalence of abnormality and clinically associated factors to PINT and quantitative vibratory perception threshold (QVT). PINT and QVT were measured by a portable peripheral nerve testing device PNS-7000, and a vibration sensation meter AU 02-B in 656 Japanese regional health checkup examinees (40-75 years old; years old). Glucose tolerance; normal (N), pre-DM, newly diagnosed DM (NDM) and known DM (KDM), and neuropathic findings (pain, paresthesia, numbness in legs and reduced ATRs) were also determined. Relationship between age, glucose tolerance, neuropathic findings and PINT or QVT were investigated by simple and multivariate analyses. In 445 non-DM subjects without neuropathic findings, normal limit value of PINT (mA) was set by quantile regression method, and relationship between prevalence of PINT or QVT abnormalities and clinical factors were examined. As results, PINT was not changed under 70 years old, then somewhat elevated. QVT elevated from 50 years old. PINT was not associated with QVT. PINT was significantly elevated in NDM and KDM. QVT was elevated in diabetes and hypertension. Among the neuropathic findings, PINT was significantly associated with only pain. By multiple regression analyses, significant aggravating factors of PINT were aging and glucose intolerance. Normal values of PINT were > 0.4 (<69 years old) and >0.5 (70< years old) Prevalence of PINT abnormality were 3%, 4%, 13% and 9% in N, pre-DM, NDM and KDM, respectively. They were significantly increased with the deterioration of glucose tolerance. QVT abnormality was not significantly increased with glucose intolerance. In conclusion, PINT reflects small nerve fiber function, and associates with DM. So, PINT may be a useful for diagnosis and evaluation of small fiber neuropathy. Disclosure H. Sasaki: None. S. Kishimoto: None. K. Ogawa: None. S. Kurisu: None. K. Nanjo: None. Funding Japan Society for the Promotion of Science

560-P: Thermal Indicators of Previously Undiagnosed Diabetic Peripheral Neuropathy

Purpose: Neurological clinical exams, quantitative sensory tests (QST), and nerve conduction studies (NCS) have been reported to have low accuracy in diagnosing diabetic peripheral neuropathy (DPN). This study explores the use of infrared (thermal) video imaging to detect small and large fiber DPN. Methods: 48 subjects with and 148 subjects without DPN were studied and compared to age-matched control subjects (n=84). All subjects’ feet were examined for sores, deformities, and other signs of disease, and patients with recent foot surgeries were excluded. Monofilament and vibration threshold testing ware performed on all subjects. Thermal videos were collected for all subjects, and NCS exams were performed on a subset of subjects. Thermal imaging followed a standard procedure: Imaging pre- and post-cooling to 2°C. A thermal classification model using thermal features extracted from the videos was developed with NCS as the reference standard to assess the performance of thermoregulation models. Results: Monofilament and vibration test results were compared with clinical diagnoses and had sensitivities of 52% and 57%, respectively. Sensitivity and specificity increase to 74% and 85% when the two tests were combined in an “either/or” decision. NCS was performed on 39 subjects: 11 control subjects, 12 subjects with clinical DPN, and 16 subjects with DM but without DPN. QST demonstrated a best sensitivity of 59% for the vibration test and a best individual specificity of 100% for the monofilament test when compared to NCS. When combined, QST demonstrated best overall sensitivity and specificity of 63% and 87%. The thermal model returned a sensitivity/specificity of 82%/94% and 91%/75% for different cut-points. Conclusions: Thermal recovery modeling from a cold stimulus yielded superior agreement with clinical and NCS diagnoses as compared to QST in the detection of DPN. A thermal imaging device can be made that is feasible for use in clinics at a lower cost than NCS devices. Disclosure M.R. Burge: None. C.S. Calder: None. J. Wigdahl: None. V. Joshi: None. X. Guo: None. J.C. Carmichael: None. P. Soliz: Stock/Shareholder; Self; VisionQuest Biomedical LLC. Funding National Institutes of Health

P58-T Electrophysiological assessment of small fibres in carpal tunnel syndrome

Background Conventional nerve conduction techniques have limitations on carpal tunnel syndrome (CTS) diagnosing, because dysfunction of small fibres is beyond the resolution of these studies. The lack of the gold standard of CTS evaluation and common misdiagnosis underlie the treatment failure. Evaluation of small fibres susceptibility to damage and the sequence of decline of different types of fibres in CTS were analyzed. Materials and methods 75 hands, in 43 patients, 35 females, 8 males, with elecrophysiologically confirmed CTS were studied. The control group consisted of 35 volunteers (63 hands), sex and age-matched. Standard motor and antidromic sensory nerve conduction velocity studies in the median and ulnar nerves, with distal onset latency, conduction velocity, and amplitude assessment were done. Conduction velocity distribution test (CVD) was performed in the same nerves with estimation of conduction velocities in 10, 50, 90 decyl, and the conduction spread between 90 and 10 decyl. Quantitative sensory testing (QST) for detection temperature, pain and vibratory theresholds were done from thenar and hypothenar skin. Results CVD values of the median nerve in all decyls differed significantly between the carpal tunnel syndrome group and the control group, without any significant differences in the spread of conduction values. The thresholds of temperature and pain were similar, but the vibratory thresholds were significantly higher in the CTS group. Conclusions Mainly large fibers of the median nerve are damaged in the initial stage of CTS. Evaluation of small fibers is not useful in the early diagnosis of CTS.

Standing on your two feet: How skin can help with balance and mobility

There are four distinct cutaneous mechanoreceptors that provide tactile input from the plantar-surface of the foot. The unique patterns of vibration, slip, pressure and stretch provide valuable information regarding the interface of the foot with the environment. This presentation will address the feasibility of foot sole skin to contribute to gait and balance control; with particular attention paid to the distribution and density of skin mechanoreceptors across the foot sole. Here Dr. Bent will talk about the potential for receptors in the skin to respond to input from the environment, and evoke changes in patterns of muscle activity; for example onset and amplitude of lower limb muscles during gait. As such there are implications for rehabilitation advancements such as insoles, orthotics and vibrating devices, whereby skin activation can influence gait outcomes. Importantly, the physical location of mechanoreceptors across the foot sole, and the physical characteristics of the skin (hardness, thickness) have implications on activation of the mechanoreceptors, their perceptual threshold and ultimately the success of clinical testing techniques. The use of microneurography in parallel with other techniques weaves together the link between standard clinical measures of tactile and vibration thresholds and actual cutaneous afferent firing thresholds. Dr Bent will aim to convince the audience that activation of these foot sole mechanoreceptors really can play a role in whole body movement and control.

A two alternative forced choice method for assessing vibrotactile discrimination thresholds in the lower limb

The development of an easy to implement, quantitative measure to examine vibration perception would be useful for future application in clinical settings. Vibration sense in the lower limb of younger and older adults was examined using the method of constant stimuli (MCS) and the two-alternative forced choice paradigm. The focus of this experiment was to determine an appropriate stimulation site on the lower limb (tendon versus bone) to assess vibration threshold and to determine if the left and right legs have varying thresholds. Discrimination thresholds obtained at two stimulation sites in the left and right lower limbs showed differences in vibration threshold across the two ages groups, but not across sides of the body nor between stimulation sites within each limb. Overall, the MCS can be implemented simply, reliably, and with minimal time. It can also easily be implemented with low-cost technology. Therefore, it could be a good candidate method to assess the presence of specific deep sensitivity deficits in clinical practice, particularly in populations likely to show the onset of sensory deficits.

Real-World Hypoglycemia Avoidance with a Continuous Glucose Monitoring System's Predictive Low Glucose Alert.

Background: Programmable and fixed auditory and/or vibratory threshold alerts are essential features of real-time continuous glucose monitoring (rtCGM) systems that provide users time to intervene before the onset of clinical hypoglycemia or hyperglycemia. A sixth-generation rtCGM system from Dexcom, Inc. (G6) includes a new alert that is triggered when an algorithm predicts that an estimated glucose value ≤55 mg/dL will occur within 20 min, allowing users more time to act to avoid hypoglycemia. We examined whether this predictive low glucose alert provided added benefit to traditional low threshold alerts.Methods: We analyzed glucose values from an anonymized sample of 1424 patients who transitioned to G6 from the preceding fifth-generation system (G5) with no predictive alert. Users with the low threshold alert setting of 70 or 80 mg/dL were evaluated separately. Receiver users, those who disabled the predictive low glucose alert, or those with <30 days of data immediately before or after the transition to G6 were excluded.Results: Percent time <54, ≤55, <70, and >250 mg/dL fell significantly after the transition to G6, independent of low threshold alert setting. Time in range improved for G6 users with a low threshold alert setting of 70 mg/dL.Conclusions: Advance warning provided by predictive low glucose alerts may further reduce hypoglycemia among rtCGM-experienced users.

(215) Differential Expression of Axonal Transport Related Genes and Pathways in Paclitaxel-Induced Peripheral Neuropathy in Breast Cancer Survivors

Taxol is a common chemotherapy (CTX) drug that is associated with the development of neuropathy. Paclitaxel-induced peripheral neuropathy (PIPN) is the dose limiting toxicity of this CTX drug. Paclitaxel exerts its therapeutic effect by binding to β-tubulin, which interferes with microtubule dynamics and results in microtubule stabilization, mitotic arrest, and apoptosis of cancer cells. However, microtubules are critical for axonal function and for the transport of essential organelles to distal nerve endings. Disruption of axonal transport (AT) can lead to axonal degeneration and neuropathy. The purpose of this pilot study was to evaluate for differential expression (DE) and perturbations in AT related genes and pathways between breast cancer (BC) survivors who did (n=25) and did not (n=25) develop PIPN. Gene expression in peripheral blood was assayed using RNA-seq. BC survivors with PIPN were significantly older; more likely to be unemployed; reported lower alcohol use; had a higher BMI and a poorer functional status; and had a higher number of lower extremity sites with loss of light touch, cold, and pain sensations, and higher vibration thresholds. No between group differences were found in the cumulative dose of paclitaxel received or in the percentage of patients who had a dose reduction or delay due to PIPN. Three candidate paclitaxel metabolizing genes were DE (i.e., TUBB4B, TUBB2A, RFX2) and two pathways associated with AT were significantly perturbed (i.e., axon guidance, regulation of actin cytoskeleton). This study is the first to provide molecular evidence that a number of axonal transport mechanisms identified in preclinical models of various types of neuropathic pain including chemotherapy-induced peripheral neuropathy are found in breast cancer survivors with persistent PIPN and suggest genes for validation and as potential therapeutic targets.

Real time end-to-end glass break detection system using LSTM deep recurrent neural network

Presently, glass windows in commercial and residential buildings are very popular. While glass has its benefits, it is also disposed to security risks. Almost all glass break detectors use a pre-determined frequency of breaking glass sound and vibration threshold signals of a pane to determine whether or not breakage has occurred. However, sounds such as thunder sounds, shouting, gunshot, hitting objects are similar in frequency and threshold value to glass breaking sounds events, and may consequently cause false positives in detection in the alarm system. The aim of this paper is to propose a new design for a glass break detection system using LSTM deep recurrent neural networks in an end to-end approach to reduce false positive alarm of state of the art glass break detectors. We utilized raw wave audio data to detect a glass break detection event in End-to-End learning approach. The key benefit of End-to-End learning is avoiding the need of hand-crafted audio features. To address the issue of a vanishing gradient and exploding gradient problem in conventional recurrent neural networks, this paper proposed deep long short term memory (LSTM) recurrent neural network to handle the sequence of the input audio data. As a real time detection result, the proposed glass break detection approach has a clear advantage over the conventional glass break detection system, as it yields significantly higher precision accuracy (99.999988 %) and suffers less from environmental noise that might cause a false alarm.

Quantitative vibratory sensation measurement is related to sensory cortical thickness in MS.

ObjectiveVibratory sensation is a quantifiable measure of physical dysfunction and is often related to spinal cord pathology; however, its association with relevant brain areas has not been fully explored. Our objective was to establish a cortical structural substrate for vibration sensation.MethodsEighty‐four individuals with multiple sclerosis (MS) (n = 54 relapsing, n = 30 progressive) and 28 controls participated in vibratory sensation threshold quantification at the great toe and a 3T MRI evaluating volume of the thalamus and cortical thickness primary and secondary sensory cortices.ResultsAfter controlling for age, sex, and disability level, vibratory sensation thresholds were significantly related to cortical thickness of the anterior cingulate (P = 0.041), parietal operculum (P = 0.022), and inferior frontal gyrus pars operculum (P = 0.044), pars orbitalis (P = 0.007), and pars triangularis (P = 0.029). Within the progressive disease subtype, there were significant relationships between vibratory sensation and thalamic volume (P = 0.039) as well as reduced inferior frontal gyrus pars operculum (P = 0.014) and pars orbitalis (P = 0.005) cortical thickness.ConclusionsThe data show significant independent relationships between quantitative vibratory sensation and measures of primary and secondary sensory cortices. Quantitative clinical measurement of vibratory sensation reflects pathological changes in spatially distinct brain areas and may supplement information captured by brain atrophy measures. Without overt relapses, monitoring decline in progressive forms of MS has proved challenging; quantitative clinical assessment may provide a tool to examine pathological decline in this cohort. These data suggest that quantitative clinical assessment may be a reliable way to examine pathological decline and have broader relevance to progressive forms of MS.

Abstract P1-11-15: Chemotherapy-induced peripheral neuropathy in breast cancer survivors: Comparison of objective and subjective measures

Abstract Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common, potentially debilitating, and dose-limiting side effect experienced by breast cancer survivors. CIPN encompasses symptoms such as pain, numbness, and tingling, which can be measured subjectively by patient-reported outcomes (PRO), or objectively by quantitative sensory testing (QST); however, little is known how QST correlates with symptom profiles measured by PRO. Methods: We conducted a cross-sectional analysis using baseline data of two ongoing clinical trials of breast cancer survivors who experienced moderate to severe CIPN defined by pain, numbness, or tingling ratings of four or greater on a numeric rating scale (NRS) after chemotherapy completion for at least three months. PRO measures of CIPN symptoms included Neuropathic Pain Scale (NPS) and Functional Assessment of Cancer Therapy-Gynecologic Oncology Group/Neurotoxicity subscale (FACT/GOG-Ntx). QST included tactile threshold (TT) measured by Von Frey's filaments, and vibration threshold (VT) measured by biothesiometer. We ran a Spearman correlation to assess the relationship between the subjective measures (NPS and FACT/GOG-Ntx) and objective measures (TT and VT QST). Results: We included 52 sets of baseline data on 50 unique patients; two patients were enrolled in both trials at different times. Mean age was 61 years (SD 10) and 66% were white. The mean NRS pain score was 3.9 (SD 2.8), numbness 5.7 (SD 2.2), and tingling 4.3 (SD 2.8) on a 0-10 scale. The mean NPS total score was 39.2 (SD 23.1) on a 0-100 scale, and FACT/GOG-Ntx was 26.2 (SD 6.8) on a 0-44 scale. High scores on NRS and NPS and low scores on FACT/GOG-Ntx signify more severe CIPN symptoms. See Table 1 for a summary of the correlation between two questions on FACT/GOG-Ntx on tingling/numbness in hands and feet, and NPS total score with QST. A moderate correlation was observed between FACT/GOG-Ntx and QST results, suggesting patient-reported hand and foot numbness or tingling is associated with decreased hand and foot tactile and vibration perception. NPS was positively correlated with tactile perception for the hand and foot, but not with vibration perception. Table 1.Correlation between objective and subjective measures of CIPN Tactile QSTVibration QST HandFeetHandFeetFACT/GOG-Ntx-0.33 (P=0.018)-0.28 (P=0.045)-0.37 (P=0.008)-0.40 (P=0.0034)NPS0.34 (P=0.015)0.32 (P=0.022)0.22 (P=0.12)0.03 (P=0.81) Conclusions: A mild to moderate correlation was observed between subjective and objective measurements of CIPN. As CIPN presents a diverse range of symptoms, better quantifying the subjective and objective measures of CIPN can help incorporate these tools in observational and intervention trials. Understanding the correlation between PRO and QST can help establish QST as a reliable objective measurement of CIPN symptoms, and enable targeted interventions to alleviate CIPN symptoms. Citation Format: Bao T, Kwon A, Piulson L, Chen P, Li Q, Patil S, Seidman A, Blinder V, Vahdat L, Zhi WI, Mao JJ. Chemotherapy-induced peripheral neuropathy in breast cancer survivors: Comparison of objective and subjective measures [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-11-15.

Cost Analysis of the Possibility of Securing an Energy-Efficient Building Against Harmful Effects of Vibrations on People

The aim of this article is to check vibrational comfort in near zero energy building (NZEB) which is often neglected for this type of building but could be annoying for residents. Building chosen for analysis is experimental building of Malopolska Laboratory of Energy Efficient Building which fulfils requirements for NZEB. The main advantage of this building is that it was design specially for research purposes and it has fourteen zones independently controlled. These zones give opportunity to ensure thermal, humidity, luminosity comfort, but do not measure vibrational comfort. Building is located in the city center of Krakow and very close to Szlak street on which cars and vans move. In this article the vibrational measurements carried out on the top floor of the building are presented. Results indicate that vibrational comfort should be taken into account in NZEB. Second part of the article describes possibility to ensure vibrational comfort in such a building by floor specially design for these purposes. In the city centres, vibro-acoustic floors could be the only solution when vibrational comfort during day or night is exceeded. Three different types of vibro-acoustic floor with different layers’ configuration are described. Their advantages and disadvantages are also shown. In the end, cost analysis is made for different types of floor solutions and the most optimal solution is chosen. The selection is made not only by economic reasons but, above all, by functional premises. The floor solution chosen to be used in Malopolska Laboratory of Energy Efficient Building first of all should ensure the vibrational comfort during daytime because it is office building not residing in the night. The owners of the building will be offered an economic option that meets the requirements of vibrational comfort during the day and an exclusive option that will ensure that the vibration threshold of perception will be not exceeded.

Monitoring on Guardrails to Afford Road Safety Using IOT

&lt;p align="justify"&gt;&lt;span&gt;The preservation of the road infrastructures has become an important issue to the road safety and structural monitoring systems industry aiming to reduce the maintenance cost and also to increase the drivers safety. The collision features of the simulation of car- guard rail. It is found that the vibration features of the guardrail within the accident have a good performance to the accident identification. The vibration data of the guardrail are recorded real-timely by the nodes with accelerator sensors on the guardrail network. Then the collision accident is identified in terms of the vibration threshold. The proposed design is a system which can detect accidents in significantly less time and sends the basic information to first aid center within a few seconds covering geographical coordinate the time and angle in which a vehicle accident had occurred. This alert message is sent to the rescue team in a short time which will help in saving the valuable lives.&lt;/span&gt;&lt;/p&gt;

Local effects of acupuncture on the median and ulnar nerves in patients with carpal tunnel syndrome: a pilot mechanistic study protocol

BackgroundWhile acupuncture’s mechanism of action is not fully understood, there is consensus that the nervous system plays a key role in processing its effects. This research is based on the structural theory of acupuncture, which aims to correlate the location of acupuncture points to peripheral nerves, spinal segments, and spinal plexuses. This mechanistic study explores the close anatomical association between the Pericardium meridian/median nerve and the Heart meridian/ulnar nerve in an attempt to produce electrophysiologic data measuring acupuncture’s direct, nerve-specific effect on the underlying nerves. Specifically, the purpose of this research is to use nerve conduction studies (NCSs) and quantitative sensory testing (QST) to assess for any local, nerve-specific effect of three acupuncture modalities on two anatomically distinct nerves in the forearm — the median and ulnar nerves — in subjects with carpal tunnel syndrome (CTS). The choice of CTS as an injured nerve model allows for comparisons between the response in an injured nerve (median) to that of a healthy one (ulnar).MethodsSubjects with mild to moderate CTS will be randomized to three intervention groups: manual acupuncture and low- and high-frequency electroacupuncture. Each subject will receive two treatments, 1 week apart, to points in the forearm, which overlay the median nerve (Pericardium meridian) or the ulnar nerve (Heart meridian). Acupuncture will be administered in random order to minimize learning effects in sensory testing. During Week 1, baseline NCS and QST (vibration and cold detection thresholds) will be obtained in both nerve territories, followed by acupuncture and post-acupuncture NCS and QST measurements in both nerve territories. During Week 2, repeat baseline QST and NCS measurements will be obtained, followed by acupuncture to points overlying the nerve not treated in Week 1, followed by post-acupuncture NCS and QST measurements in both nerve distributions.DiscussionThis works aims to capture and characterize the local effects of acupuncture on an underlying nerve and compare them to those on a neighboring nerve. Quantifying acupuncture’s effects using physiologic parameters and discrete values could standardize treatment regimens and help assess their therapeutic effect.Trial registrationClinicalTrials.gov, NCT03036657. Registered on 30 January 2017. Retrospectively registered.

Playbacks of Asian honey bee stop signals demonstrate referential inhibitory communication

Referential communication provides a sophisticated way in which animals can communicate information about their environment. Previously, research demonstrated that honey bee stop signals encode predator danger in their fundamental frequency and danger context in their duration. Here, we show that these signals also encode danger in their vibrational amplitude. Stop signals elicited by the more dangerous predator, the large hornet (Vespa mandarinia) had significantly 1.5-fold higher vibrational amplitudes than those elicited by the small hornet predator (Vespa velutina). We measured the freezing vibrational response thresholds, and show that natural signals exceed these response thresholds. Finally, with artificial playbacks of the vibratory stop signal, we demonstrate that these signals referentially encode the danger that foragers experience at food source. Stop signals elicited by the larger and significantly more dangerous predator (V. mandarinia) were significantly 1.4-fold more inhibitory than stop signals elicited by the smaller and less dangerous predator (V. velutina).

High-Performance Floating Slab Track: Design and Construction Improvements Based on Lessons Learned from Prototype Slabs

The Northgate Link extension of the Sound Transit’s Link light-rail transit system subway tunnels under the University of Washington must meet stringent vibration thresholds as agreed between Sound Transit and the university to protect vibration-sensitive research labs. To meet the vibration thresholds the design team developed a 5 Hz floating slab track with an ultra-straight rail as the appropriate solution. Considering that such a solution pushes the engineering envelope, a 440-foot prototype section with 5 Hz floating slab track and a 1000-foot section of un-isolated track with milled rail were installed in the University Link tunnels to test the design. The performances of both prototype sections were evaluated during pre-revenue service and revenue service of the University Link. Based on the performance evaluation, the design of the floating slab track was refined, and the construction tolerances were tightened. The design refinements focused on improving vibration isolation performance, including stiffer rail fasteners, slightly softer support pads, and slightly heavier slabs. The construction specifications included limits on rail undulation consistent with European standards for high-speed track, EU Type 1 rail welding standards, and implementation of a frequency response pass/fail criteria on the installed slabs. This paper provides the details of the design changes, the construction tolerances, and preliminary performance results.

Contribution of Loss of Large Fiber Function to Pain in 2 Samples of Oncology Patients.

Numbness associated with neuropathic pain suggests the loss of function in myelinated, large diameter sensory neurons. The purpose of this study was to examine the relationships between pain severity and subjective (ie, severity of numbness) and objective (ie, loss of light touch sensations, vibration thresholds) measures of loss of large fiber function in adult survivors with chemotherapy-induced peripheral neuropathy (CIPN, n=426) and breast cancer patients with persistent postsurgical pain (n=80). For both samples, average pain and numbness were evaluated using a 0 to 10 numeric rating scale. Loss of light touch sensations in the hands and feet of patients with CIPN and in the upper arm of patients at 5 and 6 months following breast cancer surgery were assessed using Semmes Weinstein monofilaments. Loss of vibration in the hands and feet of patients with CIPN was assessed using a biothesiometer. Pearson Product Moment correlation coefficients were calculated between average pain and the number or percentage of sites with loss of light touch sensations, mean vibration thresholds, and the severity of numbness. For both pain conditions, average pain scores were significantly correlated with objective measures of large fiber function (r=0.12 to 0.34; all P<0.05) and numbness (r=0.22 to 0.52; all P<0.008). Our findings, in 2 independent samples of oncology patients, suggest that loss of function of myelinated, large diameter fibers contributes to the severity of neuropathic pain.

Epigenetic aging is associated with clinical and experimental pain in community-dwelling older adults.

Gerontological research reveals considerable interindividual variability in aging phenotypes, which has motivated research efforts to identify “aging biomarkers.” Aging biomarkers are used to calculate biological age, which are better predictors of disease risk and residual lifespan when compared to chronological age alone. Emerging evidence using the epigenetic clock as an aging biomarker supports highly reliable individualized predictions about future health. This study aimed to determine whether an epigenetic aging biomarker was associated with chronic pain in older adults (60–83 years old). A subset of participants (n = 29) in the Neuromodulatory Examination of Pain and Mobility Across the Lifespan study underwent a blood draw, demographic, psychological, cognitive, and pain assessments. We estimated Horvath’s epigenetic clock and calculated the difference between epigenetic age and chronological age that has been previously reported to predict overall mortality risk. Older individuals without chronic pain (n = 9) had significantly “younger” epigenetic age compared to those with chronic pain (n = 20, p < 0.05). Older epigenetic age was associated with greater pain during daily activities (r = 0.494, p = 0.010) and anatomical pain sites (r = 0.741, p < 0.001) but not pain frequency/duration. An older epigenetic age was also associated with higher vibratory detection thresholds (r = 0.490, p = 0.021), heat pain thresholds (r = −0.478, p = 0.028), and pressure pain thresholds at the trapezius (r = −0.571, p = 0.006) but not thermal detection, pressure pain at the quadriceps or pain inhibition (p’s > 0.05). Epigenetic aging was associated with greater emotional stability (r = −0.461, p = 0.027), conscientiousness (r = −0.549, p = 0.007), and lower extraversion (r = 0.414, p = 0.049) but not depression or affect (p’s > 0.05). Epigenetic aging was also associated with lower episodic (r = −0.698, p = 0.001) and working memory (r = −0.760, p < 0.001). Our findings suggest that chronic pain is associated with accelerated epigenetic aging in healthy, community-dwelling older individuals, and future studies with larger samples are needed to confirm our findings. An aging biomarker such as the epigenetic clock may help identify people with chronic pain at greater risk of functional decline and poorer health outcomes.

Vibration testing: Optimizing methods to improve reliability.

In this study we assessed the test-retest reliability of a Rydel-Seiffer tuning fork and an electronic vibrameter with hand-held and fixed probes. Fifty healthy volunteers were assessed twice in the upper and lower limb 15 minutes apart. Reliability was assessed by intraclass correlation coefficient (ICC) and standard error of measurement (SEM). The effect of stimulus parameters on vibration disappearance threshold (VDT) was assessed by analysis of variance. All 3 tools showed good reliability (ICCs = 0.65-0.95). Vibrameter recordings with the fixed probe showed high variability. The vibrameter was more sensitive in detecting body-site and age differences in vibration thresholds than the tuning fork. Significantly higher VDT was observed when higher starting amplitudes and slower rates of change were used. The hand-held vibrameter is a superior tool to monitor vibration sense. The stimulus amplitude and rate of change are important to control as they alter VDT. Muscle Nerve 59:229-235, 2019.

IoT-Based Vibration Analytics of Electrical Machines

The aim of this paper is to propose an IoT-based model for real-time condition monitoring of electrical machines, which addresses the challenges of data storage and scalability. The proposed model is evolved with an experimental setup having two sets of dc motor coupled to ac generator and an IoT device to elucidate integrated monitoring and decision making. This IoT-based vibration analytic model uses an IoT2040 Gateway with custom Linux OS image built for acquisition and streaming of vibration signals. The Python target application acquires dc motors shaft vibration using vibration sensors and communicates the data as events to cloud through serial device driver interface. The IoT service running in cloud receives the data from multiple machines through lightweight RESTful HTTP and records the same which are retrievable for analysis and algorithm development in any platform. The retrieved data have been analyzed using the proposed statistical classification-based signal decomposition algorithm as well as time-frequency analysis to estimate the vibration thresholds of every machine connected to IoT cloud. Such estimated thresholds corresponding to different operating and environmental conditions maintained in cloud are used to build a repository of context specific solutions for machine conditions leading to improved maintenance decisions. The uniformity of threshold values obtained from IoT-based model in comparison with that of analysis carried out on the machines locally using myRIO for data acquisition ensures the integrity of the proposed statistical classification algorithm and reliability of the IoT model for condition monitoring with assured scalability.

Quantitative sensory testing in elderly: longitudinal study.

To evaluate elderly patients in a geriatric service, along with their sensory characteristics and their association with clinical aspects. This was a descriptive longitudinal study. We enrolled 36 healthy participants of both sexes in this study. The following instruments were used and evaluations performed: clinical evaluation, Mini-Mental State Exam, and quantitative sensory testing. During the follow-up, there was reduction of mean corpuscular volume at each evaluation (p < 0.001) and significant increase in mean corpuscular hemoglobin concentration (p < 0.001). There was an increase of the olfactory (p < 0.001), salty (p = 0.024), sour (p = 0.020), bitter (p = 0.001), facial cold (p = 0.019), hand cold (p = 0.004), facial tactile (p < 0.001), hand tactile (p = 0.012) and facial vibration (p = 0.018) thresholds. Previous existing morbidities were associated with sensitivity changes in the individuals in this sample. This longitudinal study suggests that the loss of sensitivity with aging may be associated with the presence of morbidities in elders.