scholarly journals Skin-interfaced microfluidic system with personalized sweating rate and sweat chloride analytics for sports science applications

2020 ◽  
Vol 6 (50) ◽  
pp. eabe3929 ◽  
Author(s):  
Lindsay B. Baker ◽  
Jeffrey B. Model ◽  
Kelly A. Barnes ◽  
Melissa L. Anderson ◽  
Stephen P. Lee ◽  
...  

Advanced capabilities in noninvasive, in situ monitoring of sweating rate and sweat electrolyte losses could enable real-time personalized fluid-electrolyte intake recommendations. Established sweat analysis techniques using absorbent patches require post-collection harvesting and benchtop analysis of sweat and are thus impractical for ambulatory use. Here, we introduce a skin-interfaced wearable microfluidic device and smartphone image processing platform that enable analysis of regional sweating rate and sweat chloride concentration ([Cl−]). Systematic studies (n = 312 athletes) establish significant correlations for regional sweating rate and sweat [Cl−] in a controlled environment and during competitive sports under varying environmental conditions. The regional sweating rate and sweat [Cl−] results serve as inputs to algorithms implemented on a smartphone software application that predicts whole-body sweating rate and sweat [Cl−]. This low-cost wearable sensing approach could improve the accessibility of physiological insights available to sports scientists, practitioners, and athletes to inform hydration strategies in real-world ambulatory settings.

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1178 ◽  
Author(s):  
Jorge Prada ◽  
Christina Cordes ◽  
Carsten Harms ◽  
Walter Lang

This contribution outlines the design and manufacturing of a microfluidic device implemented as a biosensor for retrieval and detection of bacteria RNA. The device is fully made of Cyclo-Olefin Copolymer (COC), which features low auto-fluorescence, biocompatibility and manufacturability by hot-embossing. The RNA retrieval was carried on after bacteria heat-lysis by an on-chip micro-heater, whose function was characterized at different working parameters. Carbon resistive temperature sensors were tested, characterized and printed on the biochip sealing film to monitor the heating process. Off-chip and on-chip processed RNA were hybridized with capture probes on the reaction chamber surface and identification was achieved by detection of fluorescence tags. The application of the mentioned techniques and materials proved to allow the development of low-cost, disposable albeit multi-functional microfluidic system, performing heating, temperature sensing and chemical reaction processes in the same device. By proving its effectiveness, this device contributes a reference to show the integration potential of fully thermoplastic devices in biosensor systems.


2021 ◽  
Vol 11 (5) ◽  
pp. 2093
Author(s):  
Noé Perrotin ◽  
Nicolas Gardan ◽  
Arnaud Lesprillier ◽  
Clément Le Goff ◽  
Jean-Marc Seigneur ◽  
...  

The recent popularity of trail running and the use of portable sensors capable of measuring many performance results have led to the growth of new fields in sports science experimentation. Trail running is a challenging sport; it usually involves running uphill, which is physically demanding and therefore requires adaptation to the running style. The main objectives of this study were initially to use three “low-cost” sensors. These low-cost sensors can be acquired by most sports practitioners or trainers. In the second step, measurements were taken in ecological conditions orderly to expose the runners to a real trail course. Furthermore, to combine the collected data to analyze the most efficient running techniques according to the typology of the terrain were taken, as well on the whole trail circuit of less than 10km. The three sensors used were (i) a Stryd sensor (Stryd Inc. Boulder CO, USA) based on an inertial measurement unit (IMU), 6 axes (3-axis gyroscope, 3-axis accelerometer) fixed on the top of the runner’s shoe, (ii) a Global Positioning System (GPS) watch and (iii) a heart belt. Twenty-eight trail runners (25 men, 3 women: average age 36 ± 8 years; height: 175.4 ± 7.2 cm; weight: 68.7 ± 8.7 kg) of different levels completed in a single race over a 8.5 km course with 490 m of positive elevation gain. This was performed with different types of terrain uphill (UH), downhill (DH), and road sections (R) at their competitive race pace. On these sections of the course, cadence (SF), step length (SL), ground contact time (GCT), flight time (FT), vertical oscillation (VO), leg stiffness (Kleg), and power (P) were measured with the Stryd. Heart rate, speed, ascent, and descent speed were measured by the heart rate belt and the GPS watch. This study showed that on a ≤10 km trail course the criteria for obtaining a better time on the loop, determined in the test, was consistency in the effort. In a high percentage of climbs (>30%), two running techniques stand out: (i) maintaining a high SF and a short SL and (ii) decreasing the SF but increasing the SL. In addition, it has been shown that in steep (>28%) and technical descents, the average SF of the runners was higher. This happened when their SL was shorter in lower steep and technically challenging descents.


Author(s):  
RW Meggs ◽  
RJ Watson

Put simply, ‘spoofing’ is a means of controlling the reported position and time of a GNSS receiver. Spoofing has now been well demonstrated in the experimental context, but until a few years ago it was regarded as “…a bit like UFOs: much speculation, occasional alarms at suspected instances, but little real-world evidence of its existence” (Ref. 1). In the intervening years spoofing has transformed from a research laboratory into an emerging threat. In this paper we focus on radio-frequency attack as the primary method of spoofing. However there is also the possibility of cyber-attack on GNSS systems, in which there is interception and modification of computed position between the receiver and application. It had perhaps previously been considered that the technology and know-how “barrier to entry” to produce an effective spoofer was itself a significant deterrent. However, the commercial availability of inexpensive (sub £250) software defined radio systems, low-cost computing and open-source GNSS signal generator software has all but eliminated this barrier. This paper will consider various methods of spoofing, means of detecting spoofing through analysis of signal anomalies and also mitigation of spoofing at the physical layer via the antenna and signal processing and at the software application layer through the detection of anomalies.


2014 ◽  
Vol 9 (1) ◽  
pp. 50-53
Author(s):  
Abdulaziz H. Alzeer ◽  
Hadil A.K. Al Otair

PEDIATRICS ◽  
1998 ◽  
Vol 102 (Supplement_1) ◽  
pp. 230-231
Author(s):  
Victor Chernick

Aim. To develop a method for stimulating sweating that is rapid, painless, and avoids the risk of heat stress. Background. Since the discovery that there is a high concentration of sodium and chloride in the sweat of patients with cystic fibrosis of the pancreas in 1953, the sweat test has been performed by placing the patient's body in a plastic bag with or without hot water bottles to stimulate sweating. This method is unsatisfactory because of complications such as hyperpyrexia and heat stroke. Direct injection of a cholinergic agent intradermally is painful and therefore not practical. Methods. A rheostat with a milliampere meter was constructed at a cost of ∼$7 that allowed the iontophoresis of pilocarpine into the skin using negative and positive (2-cm diameter) electrocardiography electrodes. The positive electrode was placed on the flexor surface of the arm over a filter paper soaked in 0.2 mL of 0.2% pilocarpine nitrate. Current (0.2 mA) was applied for 5 minutes and then sweat was collected onto a preweighed filter paper for 30 minutes. Sweat chloride was determined by a polarographic method. Sweat tests were performed on 25 patients with cystic fibrosis (CF), 17 asymptomatic relatives and 27 control patients. Patients with CF had sweat chloride concentration >80 mEq/L; relatives, 32.5 mEq/L (highest 57 mEq/L); and control subjects, 21.1 mEq/L (highest 60 mEq/L). Conclusions. The iontophoresis of pilocarpine into the skin is a rapid, painless, safe, and reliable method for stimulating sweating and facilitating the determination of sweat chloride concentration.


PEDIATRICS ◽  
1979 ◽  
Vol 64 (1) ◽  
pp. 50-52
Author(s):  
John D. Lloyd-Still ◽  
Stuart H. Simon ◽  
Hans U. Wessel ◽  
Lewis E. Gibson

Essential fatty acid supplementation with oral safflower oil (1 gm/kg/day) to 11 cystic fibrosis patients (aged 6 months to 14 years) for one year produced no significant change in sweat chloride concentration (mEq/liter) or sweat rate (gm/min/m2). Addition of vitamin E (10 mg/kg/day) to the safflower oil had no effect on sweat chloride concentration or rate compared to placebo. No clinical improvement could be detected compared to a control group. These results do not support previous reports of the effects of fatty acid supplementation on sweat electrolyte concentrations in cystic fibrosis.


Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1137
Author(s):  
Nika V. Petrova ◽  
Nataliya Y. Kashirskaya ◽  
Stanislav A. Krasovskiy ◽  
Elena L. Amelina ◽  
Elena I. Kondratyeva ◽  
...  

The goal was to study the phenotypic manifestations of c.3844T>C (p.Trp1282Arg, W1282R) variant, a CF-causing mutation, in patients from the Russian Federation. Clinical manifestations and complications (the age at CF diagnosis, sweat test, pancreatic status, lung function, microbial infection, body mass index (BMI), the presence of meconium ileus (MI), diabetes, and severe liver disease) were compared in four groups: group 1—patients carrying c.3844T>C and severe class I or II variant in trans; group 2—3849+10kbC>T/F508del patients; group 3—F508del/F508del patients; and group 4—patients with W1282R and “mild” variant in trans. Based on the analyses, W1282R with class I or II variant in trans appears to cause at least as severe CF symptoms as F508del homozygotes as reflected in the early age of diagnosis, high sweat chloride concentration, insufficient pancreatic function, and low lung function, in contrast to 3849+10kbC-T/F508del compound heterozygotes having milder clinical phenotypes. The W1282R pathogenic variant is seemed to lead to severe disease phenotype with pancreatic insufficiency similarly to the F508del homozygous genotype.


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