A wearable system enabling acute stress monitoring and closed-loop mitigation through transcutaneous median nerve stimulation.

Objective evaluation method for stress level analysis is important for disease prevention, health promotion, and improvement of quality of life. The past few years witnessed rapid progress in wearable health devices. Recently, many wearable devices are capable of measuring pulse rate (PR) data that reflect stress level. The rise of these wearable devices brings exciting possibilities of monitoring one's stress level and its variation in his/her everyday life. However, sampling characteristics of such wearable health devices, e.g., sampling frequency, are usually not comparable with those of instruments for clinic or research usage. For this reason, it is difficult to achieve stress evaluation by simply applying traditional methods, such as spectral analysis for heart rate variability, to the PR data measured with these wearable devices. This study aims to develop a novel evaluation index for stress analysis. The proposed method is based on Poincare plots of PR data, which may be measured using wearable health devices, and the proposed index is developed based on inter-point distance measure. Experiments with mental stress induction were conducted with seven subjects to validate the proposed stress evaluation index. In order to evaluate dynamic change of stress level, short-term, one-minute length of duration, PR data was investigated.

Mounting evidence suggests that wearable technologies using peripheral neuromodulation can provide novel ways of improving mobility and gait function in various patient populations including older adults. The purpose of this narrative review is to provide an overview of wearable technologies/devices to improve mobility and gait function through noninvasive peripheral neuromodulation in older adults over the age of 65 and to indicate the suggested mechanism of action behind these technologies. We performed searches for articles and conference abstracts written in English, using the following databases: Embase Classic+Embase from 1947 to July 15, 2021; Ovid MEDLINE; Epub Ahead of Print, In-Process, In-Data-Review & Other Non-Indexed Citations, Daily and Versions from 1946 to July 15, 2021; PubMed; and Scopus. Forty-one technologies met the inclusion/exclusion criteria. We found that the primary implementation of the 41 technologies can be divided into 3 main categories: sensory substitution, sensory augmentation (open loop, closed loop), and motor stimulation. Using these technologies, various aspects of mobility are treated or addressed, including, gait function, fall risk, foot drop, navigating environment, and postural control. This narrative review summarizes wearable technologies that are currently commercially available and in stages of research and development. Overall, studies suggest that wearable peripheral neuromodulation technologies can improve aspects of mobility for older adults. Existing literature suggests that these technologies may lead to physiological changes in the brain through sensory reweighting or other neuroplastic mechanisms to enhance the performance of mobility and gait function in older adults over the age of 65.

The Effect of Acute Psychologic Stress on Systemic and Rectal Mucosal Measures of Inflammation in Ulcerative Colitis

Increasingly, individuals with atrial fibrillation (AF) use wearable devices (hereafter wearables) that measure pulse rate and detect arrhythmia. The associations of wearables with health outcomes and health care use are unknown. To characterize patients with AF who use wearables and compare pulse rate and health care use between individuals who use wearables and those who do not. This retrospective, propensity-matched cohort study included 90 days of follow-up of patients in a tertiary care, academic health system. Included patients were adults with at least 1 AF-specific International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) code from 2017 through 2019. Electronic medical records were reviewed to identify 125 individuals who used wearables and had adequate pulse-rate follow-up who were then matched using propensity scores 4 to 1 with 500 individuals who did not use wearables. Data were analyzed from June 2020 through February 2021. Using commercially available wearables with pulse rate or rhythm evaluation capabilities. Mean pulse rates from measures taken in the clinic or hospital and a composite health care use score were recorded. The composite outcome included evaluation and management, ablation, cardioversion, telephone encounters, and number of rate or rhythm control medication orders. Among 16 320 patients with AF included in the analysis, 348 patients used wearables and 15 972 individuals did not use wearables. Prior to matching, patients using wearables were younger (mean [SD] age, 64.0 [13.0] years vs 70.0 [13.8] years; P < .001) and healthier (mean [SD] CHA2DS2-VASc [congestive heart failure, hypertension, age ≥ 65 years or 65-74 years, diabetes, prior stroke/transient ischemic attack, vascular disease, sex] score, 3.6 [2.0] vs 4.4 [2.0]; P < .001) compared with individuals not using wearables, with similar gender distribution (148 [42.5%] women vs 6722 women [42.1%]; P = .91). After matching, mean pulse rate was similar between 125 patients using wearables and 500 patients not using wearables (75.01 [95% CI, 72.74-77.27] vs 75.79 [95% CI, 74.68-76.90] beats per minute [bpm]; P = .54), whereas mean composite use score was higher among individuals using wearables (3.55 [95% CI, 3.31-3.80] vs 3.27 [95% CI, 3.14-3.40]; P = .04). Among measures in the composite outcome, there was a significant difference in use of ablation, occurring in 22 individuals who used wearables (17.6%) vs 37 individuals who did not use wearables (7.4%) (P = .001). In the regression analyses, mean composite use score was 0.28 points (95% CI, 0.01 to 0.56 points) higher among individuals using wearables compared with those not using wearables and mean pulse was similar, with a -0.79 bpm (95% CI -3.28 to 1.71 bpm) difference between the groups. This study found that follow-up health care use among individuals with AF was increased among those who used wearables compared with those with similar pulse rates who did not use wearables. Given the increasing use of wearables by patients with AF, prospective, randomized, long-term evaluation of the associations of wearable technology with health outcomes and health care use is needed.

Pain is managed using a biopsychosocial approach and pharmacological and non-pharmacological treatments. Transcutaneous electrical nerve stimulation (TENS) is a technique whereby pulsed electrical currents are administered through the intact surface of the skin with the intention of alleviating pain, akin to ‘electrically rubbing pain away’. Despite over 50 years of published research, uncertainty about the clinical efficacy of TENS remains. The purpose of this comprehensive review is to critically appraise clinical research on TENS to inform future strategies to resolve the ‘efficacy-impasse’. The principles and practices of TENS are described to provide context for readers unfamiliar with TENS treatment. The findings of systematic reviews evaluating TENS are described from a historical perspective to provide context for a critical evaluation of factors influencing the outcomes of randomized controlled trials (RCTs); including sample populations, outcome measures, TENS techniques, and comparator interventions. Three possibilities are offered to resolve the impasse. Firstly, to conduct large multi-centered RCTs using an enriched enrolment with randomized withdrawal design, that incorporates a ‘run-in phase’ to screen for potential TENS responders and to optimise TENS treatment according to individual need. Secondly, to meta-analyze published RCT data, irrespective of type of pain, to determine whether TENS reduces the intensity of pain during stimulation, and to include a detailed assessment of levels of certainty and precision. Thirdly, to concede that it may be impossible to determine efficacy due to insurmountable methodological, logistical and financial challenges. The consequences to clinicians, policy makers and funders of this third scenario are discussed. I argue that patients will continue to use TENS irrespective of the views of clinicians, policy makers, funders or guideline panel recommendations, because TENS is readily available without prescription; TENS generates a pleasant sensory experience that is similar to easing pain using warming and cooling techniques; and technological developments such as smart wearable TENS devices will improve usability in the future. Thus, research is needed on how best to integrate TENS into existing pain management strategies by analyzing data of TENS usage by expert-patients in real-world settings.

Peripheral and central nervous system effects of the cranial application of sub-threshold transcutaneous electrical nerve stimulation (TENS), of sinusoid waveform passed between earlobe electrodes at an AC frequency of 100 Hertz, were investigated. In a single-blind study, each of thirty healthy volunteer subjects was administered one 30 minute treatment of either active TENS, placebo TENS or no treatment. Pretreatment to post-treatment changes in measures of autonomic activity (blood pressure, pulse rate, peripheral vasomotor activity), somatic activity (skeletal muscle tension), and anxiety were evaluated. Significant reductions in systolic blood pressure (p less than .05), diastolic blood pressure (p less than .01), pulse rate (p less than .05), peripheral vasomotor activity (marginally significant: p less than .07) and anxiety (p less than .05) were observed subsequent to active. TENS as compared to both placebo TENS and no TENS. No significant placebo TENS effect was observed. Possible mechanisms of action of this form of cranial TENS on the peripheral and central nervous system are discussed.

Purpose: Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacological method used to reduce spasticity. It was also assumed that TENS reduces pain and therefore improves limb function. Most of the previous studies about the effect of TENS were done in the lower limb and in stroke patients. There is a lack of enough literature about the direct and indirect effects of TENS in the upper limb. Hence, our study aimed to determine whether TENS combined with therapeutic exercises helps to improves hand function by reducing spasticity in children with hemiplegic cerebral palsy (CP).Materials and methods: Twenty-nine children with hemiplegic CP were randomly assigned to the TENS group (n = 15) or the control group (n = 14). The TENS group received traditional physical therapy with the adjunct application of conventional TENS for 30 minutes (pulse duration, 250 µs; pulse rate, 100 Hz) on the wrist extensors, once daily, 3 days a week, for 8 weeks, while the control group received traditional physical therapy.Results: The results showed a significant intergroup difference in handgrip strength over the 8-week period. The time to accomplish the Jebsen Taylor Hand Function Test (JTHFT) task decreased by 48% and the ABILHAND-Kids questionnaire scores improved by 23% in the TENS group.Conclusions: The use of TENS in combination with therapeutic exercise may improve strength and hand function.

Usefulness and Safety of a Wearable Transcutaneous Electrical Nerve Stimulation Device for Promoting Exercise Therapy in Patients With Chronic Knee Pain: A Randomized Controlled Trial

Recently there has been great interest in photoplethysmogram signal processing. However, its minimally necessary sampling frequency for accurate heart rate variability parameters is ambiguous. In the present paper frequency-modulated 1.067 Hz cosine wave modelled the variable PPG in silico. The five-minute-long, 1 ms resolution master-signals were decimated (D) at 2-500 ms, then cubic spline interpolated (I) back to 1 ms resolution. The mean pulse rate, standard deviation, root mean square of successive pulse rate differences (RMSSD), and spectral components were computed by Varian 2.3 and compared to the master-series via relative accuracy error. Also Poincaré-plot morphology was assessed. Mean pulse rate is accurate down to 303 ms (D) and 400 ms (I). In low-variability series standard deviation required at least 5 ms (D) and 100 ms (I). RMSSD needed 10 ms (D), and 303 ms (I) in normal, whereas 2 ms (D) and 100 ms (I) in low- variability series. In the frequency domain 5 ms (D) and 100 ms (I) are required. 2 ms (D) and 100 ms (I) preserved the Poincaré-plot morphology. The minimal sampling frequency of PPG for accurate HRV analysis is higher than expected from the signal bandwidth and sampling theorem. Interpolation improves accuracy. The ratio of sampling error and expected variability should be considered besides the inherent sensitivity of the given parameter, the interpolation technique, and the pulse rate detection method.

Background and Aim. Non-invasive transcutaneous vagus nerve stimulation (tVNS) is increasingly investigated as a neuromodulation approach for improving sleep and autonomic regulation. Randomised trials have shown beneficial effects of tVNS on insomnia symptoms and sleep quality, although results vary depending on stimulation site and device type. Most previous studies used auricular stimulation, while wearable devices delivering stimulation in the cervical region have recently become available for consumer use. Pulsetto is a commercially available wearable non-invasive tVNS device delivering bilateral cervical stimulation through the skin. Real-world longitudinal data on sleep outcomes associated with consumer-grade VNS devices remain limited. The aim of this study was to evaluate changes in wearable-derived sleep parameters associated with regular use of this device in everyday conditions among users in the United States. Methods. This retrospective longitudinal observational study analysed sleep data linked to regular use of the Pulsetto device. Sleep outcomes were obtained from commercially available wearable devices (Garmin, Apple Watch, Oura). For each night, the stimulation session closest to bedtime was retained. Data were aligned to each user’s first recorded session and restricted to the first six weeks of use. Total sleep time was the primary outcome. Changes over time were evaluated using linear mixed-effects models with participant as a random effect. Results. After filtering, the dataset included 36 users and 969 nightly observations. Total sleep time increased across six weeks, with an estimated change of ~0.12 h/week (p &lt; 0.05), corresponding to ~35–40 min increase from Week 1 to Week 6. Secondary outcomes showed high variability due to differences in wearable devices, repeated sessions, and limited overlap of physiological metrics. Conclusions. In real-world conditions, regular use of a wearable bilateral cervical tVNS device was associated with a modest increase in sleep duration over six weeks. Variability typical of consumer-generated data limits causal interpretation, but results support feasibility of real-world monitoring and the need for controlled prospective studies. Keywords: Vagus nerve stimulation; sleep; wearable devices; real-world data; longitudinal study

Flexible ferroelectric wearable devices for medical applications.

Wearable smart devices have gradually become indispensable devices in people’s lives. Their security and privacy have gained increasing popularity among the public due to their ability to monitor and record various aspects of users’ daily activities and health data. These devices maintain a wireless connection with mobile phones through periodic signal transmissions, which can be intercepted and analyzed by external observers. While these signal packets contain valuable information about the device owner, the identity of the actual user remains unknown. In this study, we propose two approaches to link wearable smart devices with users’ mobile phones, which serve as electronic identities, to enable novel applications such as multi-device authentication and user-device graph construction for targeted advertising. To establish this linkage, we propose two approaches: a passive-sniffing-based linking approach and an active-interference-based linking approach, which solve the problem of sniffing Bluetooth Low Energy broadcast packets in two stages of Bluetooth Low Energy communication. Through experiments conducted across three scenarios, we demonstrate that seven wearable devices can be successfully linked with an accuracy rate exceeding 80%, with accuracy rates approaching 100% when a device is recorded more than 11 times. Additionally, we find that four wearable devices can be linked via an active-interference-based linking approach with an accuracy rate exceeding 70%. Our results highlight the potential of wearable devices and mobile phones as a means of establishing user identities and enabling the development of more sophisticated applications in the field of wearable technology.

Emerging intelligent wearable devices for cardiovascular health monitoring

This study aimed to evaluate and compare the effectiveness of transcutaneous electric nerve stimulation (TENS) and photobiostimulation using diode LASER, prior to local anaesthesia administration in children undergoing bilateral orthodontic extractions. A split-mouth, parallel arm, Double blinded, randomized clinical trial was conducted on children (12 - 16 yrs) undergoing bilateral orthodontic extractions. Patients were randomly assigned to receive either TENS or PBST. Subjective and Objective parameters for anxiety and pain were assessed, and evaluated for statistical significance (p < 0.05). In this study with 104 patients (mean age 13.59), the TENS group showed significantly lower mean pain scores (WBPRS) for needle insertion (2.30 ± 2.7) versus PBST (5.03 ± 3.1, p < 0.01), LA administration (2.11 ± 2.8 vs. 4.84 ± 2.7, p < 0.01), and extraction (1.92 ± 2.6 vs. 3.23 ± 5.1, p < 0.01). TENS also led to a faster onset of local anesthesia (96.15 s ± 13.9) compared to PBST (155.38 s ± 91, p < 0.05), indicating enhanced efficacy for pain reduction and anesthesia speed. Physiological parameters like pulse rate and salivary pH also showed significant improvements with TENS. Hence TENS and PBST both came out as effective alternatives for topical anesthesia. Both TENS and PBST proved to be effective alternatives to topical anesthesia, TENS therapy with the Synapse Dental Pain Eraser (DPE) demonstrated greater effectiveness in reducing pain and anxiety, reflecting it as a promising option for pediatric patients. However further research is needed to refine and optimize pain management strategies using these alternatives in pediatric dentistry. CTRI Number- CTRI/2022/09/045460 [Registered on: 13/09/2022] Trial Registered Prospectively.

Some effects of sub-threshold sine-wave transcutaneous electrical nerve stimulation (TENS), passed between earlobe electrodes at a constant alternating current (AC) frequency of 100 Hertz (Hz), were investigated in 90 normal subjects after 30 minutes of treatment, and after 3 minutes of standardized mental stress (mental arithmetic) which immediately followed the 30 minute treatment. In a double-blind protocol, five groups received 1) active TENS during treatment and active TENS during stress; 2) active TENS during treatment and placebo TENS during stress; 3) placebo TENS during treatment and placebo TENS during stress; 4) placebo TENS during treatment and active TENS during stress; and 5) no treatment during both treatment and stress. Results showed significant reductions in systolic blood pressure, pulse rate and anxiety, but not in diastolic blood pressure or peripheral vascular tension, after 30 minutes of active TENS as compared to no treatment. No placebo TENS effect was observed. No significant differences were observed between active TENS; placebo TENS and no treatment in physiological or psychological response to the stress procedure. Results are discussed in terms of the applicability of this technique to the management of stress.