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Biosensors Jun 2023Flexible and wearable biosensors have received tremendous attention over the past decade owing to their great potential applications in the field of health and medicine.... (Review)
Review
Flexible and wearable biosensors have received tremendous attention over the past decade owing to their great potential applications in the field of health and medicine. Wearable biosensors serve as an ideal platform for real-time and continuous health monitoring, which exhibit unique properties such as self-powered, lightweight, low cost, high flexibility, detection convenience, and great conformability. This review introduces the recent research progress in wearable biosensors. First of all, the biological fluids often detected by wearable biosensors are proposed. Then, the existing micro-nanofabrication technologies and basic characteristics of wearable biosensors are summarized. Then, their application manners and information processing are also highlighted in the paper. Massive cutting-edge research examples are introduced such as wearable physiological pressure sensors, wearable sweat sensors, and wearable self-powered biosensors. As a significant content, the detection mechanism of these sensors was detailed with examples to help readers understand this area. Finally, the current challenges and future perspectives are proposed to push this research area forward and expand practical applications in the future.
Topics: Wearable Electronic Devices; Biosensing Techniques; Sweat; Monitoring, Physiologic
PubMed: 37366995
DOI: 10.3390/bios13060630 -
Experimental Physiology Feb 2020What is the central question of this study? We evaluated whether regional variations exist in NO-dependent cutaneous vasodilatation and sweating during cholinergic...
NEW FINDINGS
What is the central question of this study? We evaluated whether regional variations exist in NO-dependent cutaneous vasodilatation and sweating during cholinergic stimulation. What is the main finding and its importance? Peak cutaneous vasodilatation and sweating were greater on the torso than the forearm. Furthermore, we found that NO was an important modulator of cholinergic cutaneous vasodilatation, but not sweating, across body regions, with a greater contribution of NO to cutaneous vasodilatation in the limb compared with the torso. These findings advance our understanding of the mechanisms influencing regional variations in cutaneous vasodilator and sweating responses to pharmacological stimulation.
ABSTRACT
Regional variations in cutaneous vasodilatation and sweating exist across the body. Nitric oxide (NO) is an important modulator of these heat loss responses in the forearm. However, whether regional differences in NO-dependent cutaneous vasodilatation and sweating exist remain uncertain. In 14 habitually active young men (23 ± 4 years of age), cutaneous vascular conductance (CVC ) and local sweat rates were assessed at six skin sites. On each of the dorsal forearm, chest and upper back (trapezius), sites were continuously perfused with either lactated Ringer solution (control) or 10 mm N -nitro-l-arginine (l-NNA; an NO synthase inhibitor) dissolved in Ringer solution, via microdialysis. At all sites, cutaneous vasodilatation and sweating were induced by co-administration of the cholinergic agonist methacholine (1, 10, 100, 1000 and 2000 mm; 25 min per dose) followed by 50 mm sodium nitroprusside (20-25 min) to induce maximal vasodilatation. The l-NNA attenuated CVC relative to the control conditions for all regions (all P < 0.05), and NO-dependent vasodilatation was greater at the forearm compared with the back and chest (both P < 0.05). Furthermore, maximal vasodilatation was higher at the back and chest relative to the forearm (both P < 0.05). Conversely, l-NNA had negligible effects on sweating across the body (all P > 0.05). Peak local sweat rate was higher at the back relative to the forearm (P < 0.05), with a similar trend observed for the chest. In habitually active young men, NO-dependent cholinergic cutaneous vasodilatation varied across the body, and the contribution to cholinergic sweating was negligible. These findings advance our understanding of the mechanisms influencing regional variations in cutaneous vasodilatation and sweating during pharmacological stimulation.
Topics: Adult; Dose-Response Relationship, Drug; Enzyme Inhibitors; Humans; Injections, Subcutaneous; Male; Methacholine Chloride; Muscarinic Agonists; Nitric Oxide Synthase; Nitroarginine; Skin; Sweating; Vasodilation; Young Adult
PubMed: 31821642
DOI: 10.1113/EP088295 -
American Journal of Physiology.... Aug 2022Both adult females and children have been reported to have a lower sweating capacity and thus reduced evaporative heat loss potential that may increase their... (Review)
Review
Both adult females and children have been reported to have a lower sweating capacity and thus reduced evaporative heat loss potential that may increase their susceptibility to exertional hyperthermia in the heat. Compared with males, females have a lower maximal sweat rate and thus a theoretically lower maximum skin wettedness due to a lower sweat output per gland. Similarly, children have been suggested to be disadvantaged in high ambient temperatures due to a lower sweat production and therefore reduced evaporative capacity, despite modifications of heat transfer due to physical attributes and possible evaporative efficiency. The reported reductions in the sudomotor activity of females and children suggest a lower sweating capacity in girls. However, because of the complexities of isolating sex and maturation from the confounding effects of morphological differences (e.g., body surface area-to-mass ratio) and metabolic heat production, limited evidence exists supporting whether children, and, more specifically, girls are at a thermoregulatory disadvantage. Furthermore, a limited number of child-adult comparison studies involve females and very few studies have directly compared regional and whole body sudomotor activity between boys and girls. This minireview highlights the exercise-induced sudomotor response of females and children, summarizes previous research investigating the sudomotor response to exercise in girls, and suggests important areas for further research.
Topics: Adult; Body Temperature; Body Temperature Regulation; Female; Heat Stress Disorders; Heat-Shock Response; Hot Temperature; Humans; Male; Sweating
PubMed: 35670483
DOI: 10.1152/ajpregu.00328.2021 -
Skin Research and Technology : Official... Mar 2022While sunbathing of performing outdoor sport activities, sunscreens are important for protection of uncovered skin against ultraviolet (UV) radiation. However,...
BACKGROUND
While sunbathing of performing outdoor sport activities, sunscreens are important for protection of uncovered skin against ultraviolet (UV) radiation. However, perspiration negatively affects the performance of a sunscreen film by weakening its substantivity and uniformity through the activation of two mechanisms, namely sunscreen wash-off and sunscreen redistribution.
MATERIAL AND METHODS
We used a perspiring skin simulator to investigate the effect of sunscreen formulation on its efficiency upon sweating. Specifically, we modified the sunscreen formulation by incorporating a hydrophobic film former and adding water-absorbing particles. Sunscreen performance before and after perspiration is assessed by in vitro sun protection factor measurements, direct detection of changes in the sunscreen distribution using UV reflectance imaging, and by coherent anti-Stokes Raman scattering (CARS) microscopy for microscopic characterization of the UV filter relocation.
RESULTS
The results show that incorporating a hydrophobic film former can decrease sunscreen wash-off due to sweating, while an excessive amount of film former might negatively affect the sunscreen distribution. The addition of water-absorbing particles, on the other hand, had either a negative or positive impact on the sunscreen substantivity, depending on the particle properties. While the addition of large water-absorbing particles appeared to increase sunscreen redistribution, smaller particles that could form a gel-like structure upon contact with water, appeared to change sunscreen wetting and sweat droplet spreading, thereby decreasing sunscreen wash-off and sunscreen redistribution.
CONCLUSIONS
We find that using a combination of hydrophobic film formers, which increase water resistance, and small water-absorbing particles, which change the wetting behavior, can make sunscreen formulations more sweat-resistant and less runny.
Topics: Humans; Skin; Sunscreening Agents; Sweat; Sweating; Ultraviolet Rays
PubMed: 34752663
DOI: 10.1111/srt.13115 -
Sensors (Basel, Switzerland) Nov 2020Non-invasive healthcare technologies are an important part of research and development nowadays due to the low cost and convenience offered to both healthcare receivers... (Review)
Review
Non-invasive healthcare technologies are an important part of research and development nowadays due to the low cost and convenience offered to both healthcare receivers and providers. This work overviews the recent advances in the field of non-invasive electrochemical biosensors operating in secreted human physiological fluids, viz. tears, sweat, saliva, and urine. Described electrochemical devices are based on different electrochemical techniques, viz. amperometry, coulometry, cyclic voltammetry, and impedance spectroscopy. Challenges that confront researchers in this exciting area and key requirements for biodevices are discussed. It is concluded that the field of non-invasive sensing of biomarkers in bodily fluid is highly convoluted. Nonetheless, if the drawbacks are appropriately addressed, and the pitfalls are adroitly circumvented, the approach will most certainly disrupt current clinical and self-monitoring practices.
Topics: Biosensing Techniques; Body Fluids; Electrochemical Techniques; Humans; Saliva; Sweat; Tears; Urine
PubMed: 33171750
DOI: 10.3390/s20216352 -
The Thoracic and Cardiovascular Surgeon Mar 2022Endoscopic thoracic sympathicotomy is an effective approach to the treatment of idiopathic localized hyperhidrosis, and compensatory sweating is the main reason for...
BACKGROUND
Endoscopic thoracic sympathicotomy is an effective approach to the treatment of idiopathic localized hyperhidrosis, and compensatory sweating is the main reason for patient dissatisfaction. Our study discusses both the long-term outcomes of sympathicotomy and the course of compensatory sweating.
METHODS
Patients with palmar and/or axillary hyperhidrosis who were operated by the same surgical team between January 2008 and December 2014 were included in the study. After at least 5 years (60 months) from operation, patients were questioned about their treatment outcomes by using an original survey form.
RESULTS
Of the 137 patients included in the study, 88 (64.2%) were female and 49 (35.8%) were male. The mean time from the operation to the survey interview was 80.9 ± 14.1 (64-136) months. After operation, complaints disappeared in 95.1% of the patients, and decreased in 4.9% with palmar hyperhidrosis. Complaints completely disappeared in 12.9% and decreased in 81.7% of the patients with axillary hyperhidrosis. Ninety-seven (70.8%) of the patients described increased sweating in some parts of their body after operation but only 47 reached an uncomfortable intensity. The number of patients who regretted the operation due to the compensatory sweating was 13 (9.5%). The patients' overall scoring of the operation and procedure was calculated as 8.0 ± 2.1 (0-10 points) out of 10.
CONCLUSION
Endoscopic thoracic sympathicotomy's long-term outcomes are also satisfactory in the treatment of palmar and axillary hyperhidrosis. Compensatory sweating may decrease over time, only a minority of patients will express regret at undergoing the treatment.
Topics: Endoscopy; Female; Humans; Hyperhidrosis; Male; Patient Satisfaction; Sweating; Sympathectomy; Treatment Outcome
PubMed: 34044464
DOI: 10.1055/s-0041-1728777 -
Biosensors Feb 2023Biological information detection technology is mainly used for the detection of physiological and biochemical parameters closely related to human tissues and organ... (Review)
Review
Biological information detection technology is mainly used for the detection of physiological and biochemical parameters closely related to human tissues and organ lesions, such as biomarkers. This technology has important value in the clinical diagnosis and treatment of chronic diseases in their early stages. Wearable biosensors can be integrated with the Internet of Things and Big Data to realize the detection, transmission, storage, and comprehensive analysis of human physiological and biochemical information. This technology has extremely wide applications and considerable market prospects in frontier fields including personal health monitoring, chronic disease diagnosis and management, and home medical care. In this review, we systematically summarized the sweat biomarkers, introduced the sweat extraction and collection methods, and discussed the application and development of epidermal wearable biosensors for monitoring biomarkers in sweat in preclinical research in recent years. In addition, the current challenges and development prospects in this field were discussed.
Topics: Humans; Sweat; Wearable Electronic Devices; Biosensing Techniques; Biomarkers; Monitoring, Physiologic
PubMed: 36979525
DOI: 10.3390/bios13030313 -
Biosensors Jan 2023The current physical health care system has gradually evolved into a form of virtual hospitals communicating with sensors, which can not only save time but can also... (Review)
Review
The current physical health care system has gradually evolved into a form of virtual hospitals communicating with sensors, which can not only save time but can also diagnose a patient's physical condition in real time. Textile-based wearable sensors have recently been identified as detection platforms with high potential. They are developed for the real-time noninvasive detection of human physiological information to comprehensively analyze the health status of the human body. Sweat comprises various chemical compositions, which can be used as biomarkers to reflect the relevant information of the human physiology, thus providing references for health conditions. Combined together, textile-based sweat sensors are more flexible and comfortable than other conventional sensors, making them easily integrated into the wearable field. In this short review, the research progress of textile-based flexible sweat sensors was reviewed. Three mechanisms commonly used for textile-based sweat sensors were firstly contrasted with an introduction to their materials and preparation processes. The components of textile-based sweat sensors, which mainly consist of a sweat transportation channel and collector, a signal-selection unit, sensing elements and sensor integration and communication technologies, were reviewed. The applications of textile-based sweat sensors with different mechanisms were also presented. Finally, the existing problems and challenges of sweat sensors were summarized, which may contribute to promote their further development.
Topics: Humans; Sweat; Wearable Electronic Devices; Textiles; Biomarkers
PubMed: 36671962
DOI: 10.3390/bios13010127 -
Journal of the Royal Society, Interface Oct 2019The state-of-the-art in wearable flexible sensors (WFSs) for sweat analyte detection was investigated. Recent advances show the development of integrated, mechanically... (Review)
Review
The state-of-the-art in wearable flexible sensors (WFSs) for sweat analyte detection was investigated. Recent advances show the development of integrated, mechanically flexible and multiplexed sensor systems with on-site circuitry for signal processing and wireless data transmission. When compared with single-analyte sensors, such devices provide an opportunity to more accurately analyse analytes that are dependent on other parameters (such as sweat rate and pH) by improving calibration from real-time analysis, while maintaining a lightweight and wearable design. Important health conditions can be monitored and on-demand regulating drugs can be delivered using integrated wearable systems but require correlation verification between sweat and blood measurements using validation tests before any clinical application can be considered. Improvements are necessary for device sensitivity, accuracy and repeatability to provide more reliable and personalized continuous measurements. With rapid recent development, it can be concluded that non-invasive WFSs for sweat analysis have only skimmed the surface of their health monitoring potential and further significant advancement is sure to be made in the medical field.
Topics: Humans; Monitoring, Physiologic; Signal Processing, Computer-Assisted; Sweat; Wearable Electronic Devices
PubMed: 31594525
DOI: 10.1098/rsif.2019.0217 -
Sensors (Basel, Switzerland) Jan 2021Near-field communication (NFC) is a low-power wireless communication technology used in contemporary daily life. This technology contributes not only to user... (Review)
Review
Near-field communication (NFC) is a low-power wireless communication technology used in contemporary daily life. This technology contributes not only to user identification and payment methods, but also to various biomedical fields such as healthcare and disease monitoring. This paper focuses on biomedical applications among the diverse applications of NFC. It addresses the benefits of combining traditional and new sensors (temperature, pressure, electrophysiology, blood flow, sweat, etc.) with NFC technology. Specifically, this report describes how NFC technology, which is simply applied in everyday life, can be combined with sensors to present vision and opportunities to modern people.
Topics: Communication; Humans; Sweat; Wireless Technology
PubMed: 33498589
DOI: 10.3390/s21030703