A Noninvasive Wearable Device for Real-Time Monitoring of Secretion Sweat Pressure by Digital Display

Estimation of the Number of Active Sweat Glands Through Discrete Sweat Sensing

Sweat is a biomarker-rich fluid with potential for continuous patient monitoring via wearable devices. However, biomarker concentrations vary with the sweat rate per gland, posing a challenge for sweat sensing. To address this, we propose an algorithm to compute both the number of active sweat glands and their individual sweat rates. We developed models of sweat glands and a discrete sweat-sensing device to sense sweat volume. Our algorithm estimates the number of active glands by decomposing the signal into patterns generated by the individual sweat glands, allowing for the calculation of individual sweat rates. We assessed the algorithm's accuracy using synthetic datasets for varying physiological parameters (sweat rate and number of active sweat glands) and device layouts. The results show that device layout significantly affects accuracy, with error rates below 0.2% for low and medium sweat rates (below 0.2 nL min-1 per gland). However, the method is not suitable for high sweat rates. The suitable sweat rate range can be adapted to different needs through the choice of device. Based on our findings, we provide recommendations for optimal device layouts to improve accuracy in estimating active sweat glands. This is the first study to focus on estimating the sweat rate per gland, which essential for accurate biomarker concentration estimation and advancing sweat sensing towards clinical applications.

Innovative Material-Based Wearable Non-Invasive Electrochemical Sweat Sensors towards Biomedical Applications

Sweat is an accessible biofluid that provides useful physiological information about the body's biomolecular state and systemic health. Wearable sensors possess various advantageous features, such as lightweight design, wireless connectivity, and compatibility with human skin, that make them suitable for continuous monitoring. Wearable electrochemical sweat sensors can diagnose diseases and monitor health conditions by detecting biomedical signal changes in sweat. This paper discusses the state-of-the-art research in the field of wearable sweat sensors and the materials used in their construction. It covers biomarkers present in sweat, sensing modalities, techniques for sweat collection, and ways to power these sensors. Innovative materials are categorized into three subcategories: sweat collection, sweat detection, and self-powering. These include substrates for sensor fabrication, analyte detection electrodes, absorbent patches, microfluidic devices, and self-powered devices. This paper concludes by forecasting future research trends and prospects in material-based wearable non-invasive sweat sensors.

Fluid Status Vulnerability in Older Adults

There is a growing body of evidence about physiological changes with age that impact fluid and electrolyte balance. It is important that infusion nurses have knowledge in managing care for geriatric patients so they can identify these changes when they are exhibited. Knowing how to minimize the effect of these changes on the health of older adults is critical. The infusion nurse with knowledge of geriatric-focused care can avoid complications and critical illness in older adults. In addition, it is important to provide specific patient education that is grounded in geriatric best practices. This information will assist older adults to better protect themselves from dehydration, kidney injury, and other complications associated with fluid balance, such as delirium. This article reviews the literature on specific changes with aging that predispose older adults to adverse complications with fluid imbalance. New technology in geriatrics that can improve management of fluid status, such as dehydration and electrolyte monitors, are also discussed. This review included searches of the Medline®/PubMed® Database using MeSH terms (National Library of Medicine). Search terms included the following: aging-biological; aging kidney; water-electrolyte imbalance; dehydration; hypo-hypernatremia; hypo-hyperkalemia; delirium; wearable technology; and hydration monitors.

Design of a gradient-rheotaxis microfluidic chip for sorting of high-quality Sperm with progressive motility

Assisted reproductive technology (ART) is an important invention for the treatment of human infertility, and the isolation of high-quality sperm with progressive motility is one of the most critical steps that eventually affect the fertilization rate. Conventional sperm separation approaches include the swim-up method and density gradient centrifugation. However, the quality of isolated sperm obtained from both approaches can still be improved by improving sorted sperm motility, minimizing the DNA fragmentation rate, and removing abnormal phenotypes. Here, we report a Progressive Sperm Sorting Chip (PSSC) for high-quality sperm isolation. Based on the rheotaxis behavior of sperm, a gradient flow field is created in the chip for progressive sperm sorting. Clinical experiment results for 10 volunteers showed that greater than 90% of isolated sperm exhibit high motility (> 25 μm/s), high linearity (0.8), and a very low DNA fragmentation rate (< 5%). In addition, the whole process is label and chemical free. These features aid in gentle sperm sorting to obtain healthy sperm. This device uniquely enables the selection of high-quality sperm with progressive motility and might be clinically applied for infertility treatment in the near future.

A negative-work knee energy harvester based on homo-phase transfer for wearable monitoring devices

Wearable health monitoring devices can effectively capture human body information and are widely used in health monitoring, but battery life is an important bottleneck in its development. A full negative-work energy harvester based on the homo-phase transfer mechanism by analyzing human motion characteristics was proposed in this paper. The system was designed based on the homo-phase transfer mechanism, including a motion input module, gear acceleration module, energy conversion module, and electric energy storage module. The output performance in three human-level, downhill, and running states was tested, respectively. Finally, we have evaluated the feasibility of an energy harvester powering wearable health monitoring devices, and the harvester can generate 17.40 J/day power, which can satisfy the normal operation of a typical health monitoring device. This study has certain promoting significance for the development of a new generation of human health monitoring.

Wearable Microfluidics for Continuous Assay

The development of wearable devices provides approaches for the realization of self-health care. Easily carried wearable devices allow individual health monitoring at any place whenever necessary. There are various interesting monitoring targets, including body motion, organ pressure, and biomarkers. An efficient use of space in one small device is a promising resolution to increase the functions of wearable devices. Through integration of a microfluidic system into wearable devices, embedding complicated structures in one design becomes possible and can enable multifunction analyses within a limited device volume. This article reviews the reported microfluidic wearable devices, introduces applications to different biofluids, discusses characteristics of the design strategies and sensing principles, and highlights the attractive configurations of each device. This review seeks to provide a detailed summary of recent advanced microfluidic wearable devices. The overview of advanced key components is the basis for the development of future microfluidic wearable devices.

A sensitive enzyme-free electrochemical sensor based on a rod-shaped bimetallic MOF anchored on graphene oxide nanosheets for determination of glucose in huangshui

In this work, we propose a bimetallic Ni-Co based MOF attached to graphene oxide (GO) by a one-step hydrothermal approach which may be employed as an electrochemical enzyme-free glucose sensor. Due to the obvious synergistic catalysis of Ni and Co, as well as the combination of NiCo-MOF and GO, NiCo-MOF/GO not only enhances energy transfer and electrocatalytic performance but also provides a larger surface area and more active sites. Electrochemical studies show that NiCo-MOF/GO exhibits outstanding electrochemical activity, with a sensitivity of 11 177 μA mM^-1 cm^-2 and 4492 μA mM^-1 cm^-2 in the linear ranges of 1-497 μM and 597-3997 μM, a detection limit of 0.23 μM, and a response time of 2 seconds. More importantly, the newly fabricated sensor is successfully applied for glucose determination in huangshui. This method provides a novel strategy for the controlled fermentation process and product quality of Chinese baijiu.

Hand-Powered Point-of-Care: Centrifugal Microfluidic Platform for Urine Routine Examination (μCUREX)

Urinalysis is one of the simplest and most common medical tests in modern cities. With the assistance of professional technicians and equipment, people in metropolitan areas can effortlessly acquire information about their physiological conditions from traditional clinical laboratories. However, the threshold, including precise benchtop equipment and well-trained personnel, still remains a considerable dilemma for residents in healthcare-poor areas. Hence, it is a crucial and urgent topic to develop a smart and affordable widget to address this challenge. To improve the healthcare rights of residents, we proposed a disposable centrifugal microfluidic urine routine examination platform (named μCUREX) actuated with a modified hand-powered fan. Two parts of urinalysis (sediment test and chemical strip test) were integrated into the μCUREX disc. The influence on sedimentation by variant hand-powered manipulation was simulated using COMSOL. As a result, more than 70% of the sediment can be collected. Moreover, the color change of chemical strip papers (indicators for glucose, pH, protein, and occult blood) was recorded with a 3D-printed studio and analyzed after reaction with chemical-spiked and pH-adjusted artificial and human urine specimens. The whole process can be completed within 10 min, with only 200 μL of urine needed. In conclusion, we successfully constructed an ultra-low-cost point-of-care platform for urinalysis in extremely resource-poor settings. The handy size, high affordability, and user-friendliness of the μCUREX disc provide strong potential and feasibility in solving problems in resource-poor settings. Furthermore, we highly expect the μCUREX platform to improve the level of healthcare in resource-limited areas.

Wearable hydrogel patch with noninvasive, electrochemical glucose sensor for natural sweat detection

Recent advances in microelectronics and electrochemical sensing platforms have preceded the development of devices for personal monitoring and managing physiological and metabolic information that exploit sweat as a noninvasive, convenient approach for providing information about underlying health conditions, such as glucose level monitoring. Although most sweat glucose sensors have targeted applications during exercise and other active stimulation induced-sweat, natural sweating offers an attractive alternative with minimal effect on users that can be accessed during routine and sedentary activities without impeding personal lifestyle and preserves the correlation between blood and sweat glucose. Here, we present a noninvasive sweat glucose sensor with convenient hydrogel patches for rapid sampling of natural perspiration without external activities that stimulate sweating. The wearable hydrogel patch rapidly takes up natural sweat from the hand and serves as a medium for electrochemical sensing. A prussian blue-doped poly(3,4-ethylenedioxythiophene nanocomposite (PB-PEDOT NC) electrode provides cost-effective, stable and excellent electrocatalytic activity in sweat glucose measurements. We demonstrated sweat glucose sensor functionality by long-term measurements of glucose in sweat from human subjects consuming food and drinks. By enabling the analysis of sweat glucose during routine and sedentary activities, the sweat glucose sensor shows great promise for clinical-grade glucose management and enlarges the scope of next-generation noninvasive sensing systems.

Passively driven microfluidic device with simple operation in the development of nanolitre droplet assay in nucleic acid detection

Since nucleic acid amplification technology has become a vital tool for disease diagnosis, the development of precise applied nucleic acid detection technologies in point-of care testing (POCT) has become more significant. The microfluidic-based nucleic acid detection platform offers a great opportunity for on-site diagnosis efficiency, and the system is aimed at user-friendly access. Herein, we demonstrate a microfluidic system with simple operation that provides reliable nucleic acid results from 18 uniform droplets via LAMP detection. By using only micropipette regulation, users are able to control the nanoliter scale of the droplets in this valve-free and pump-free microfluidic (MF) chip. Based on the oil enclosure method and impermeable fabrication, we successfully preserved the reagent inside the microfluidic system, which significantly reduced the fluid loss and condensation. The relative standard deviation (RSD) of the fluorescence intensity between the droplets and during the heating process was < 5% and 2.0%, respectively. Additionally, for different nucleic acid detection methods, the MF-LAMP chip in this study showed good applicability to both genome detection and gene expression analysis.

Blink-sensing glasses: A flexible iontronic sensing wearable for continuous blink monitoring

Blink reflex has long been considered closely related to physiological states, from which abundant information on ocular health and activities can be revealed. In this study, a smart glasses wearable has been developed, incorporating a flexible and sensitive pressure sensor, to monitor blink patterns by continuously detecting ocular muscular movements, referred to as blink-sensing glasses. By applying the emerging flexible iontronic sensing (FITS) sensor with the sensitivity of 340 pF/mmHg, the skin pressure variations induced by movements of the orbicularis oculi muscles can be monitored in real time. The blink-sensing glasses can successfully capture blink patterns with a high accuracy of 96.3% and have been used to differentiate the blink features from both dry-eye subjects and healthy controls. This device can be potentially used as a new clinical and research monitoring tool for continuous eye blink analysis, while providing patients with high comfortableness in long-term ambulatory and home settings.

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Blink-sensing glasses can capture blink patterns with clinical-grade high accuracy

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A FITS sensor is applied to monitor the blink by detecting the muscle movement

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Blink-sensing glasses can be of potential use to prognose the dry eye

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The glasses are a continuous detection manner with immunity to ambient lights

Integration of Ni/NiO nanoparticles and a microfluidic ELISA chip to generate a sensing platform for Streptococcus pneumoniae detection

Enzyme-linked immunosorbent assays (ELISAs) are tests that uses antibody recognition and enzyme catalytic activity to identify a substance, and they have been widely used as a diagnostic tool in the clinic.