scholarly journals Performance of Seven Consumer Sleep-Tracking Devices Compared with Polysomnography

SLEEP ◽  
2020 ◽  
Author(s):  
Evan D Chinoy ◽  
Joseph A Cuellar ◽  
Kirbie E Huwa ◽  
Jason T Jameson ◽  
Catherine H Watson ◽  
...  

Abstract Study Objectives Consumer sleep-tracking devices are widely used and becoming more technologically advanced, creating strong interest from researchers and clinicians for their possible use as alternatives to standard actigraphy. We therefore tested the performance of many of the latest consumer sleep-tracking devices, alongside actigraphy, versus the gold-standard sleep assessment technique, polysomnography (PSG). Methods In total, 34 healthy young adults (22 women; 28.1 ± 3.9 years, mean ± SD) were tested on three consecutive nights (including a disrupted sleep condition) in a sleep laboratory with PSG, along with actigraphy (Philips Respironics Actiwatch 2) and a subset of consumer sleep-tracking devices. Altogether, four wearable (Fatigue Science Readiband, Fitbit Alta HR, Garmin Fenix 5S, Garmin Vivosmart 3) and three non-wearable (EarlySense Live, ResMed S+, SleepScore Max) devices were tested. Sleep/wake summary and epoch-by-epoch agreement measures were compared with PSG. Results Most devices (Fatigue Science Readiband, Fitbit Alta HR, EarlySense Live, ResMed S+, SleepScore Max) performed as well as or better than actigraphy on sleep/wake performance measures, while the Garmin devices performed worse. Overall, epoch-by-epoch sensitivity was high (all ≥0.93), specificity was low-to-medium (0.18-0.54), sleep stage comparisons were mixed, and devices tended to perform worse on nights with poorer/disrupted sleep. Conclusions Consumer sleep-tracking devices exhibited high performance in detecting sleep, and most performed equivalent to (or better than) actigraphy in detecting wake. Device sleep stage assessments were inconsistent. Findings indicate that many newer sleep-tracking devices demonstrate promising performance for tracking sleep and wake. Devices should be tested in different populations and settings to further examine their wider validity and utility.

Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
R. Espinosa ◽  
M. M. Le Beau

We have shown previously that isotope-labelled nucleotides in human metaphase chromosomes can be detected and mapped by imaging secondary ion mass spectrometry (SIMS), using the University of Chicago high resolution scanning ion microprobe (UC SIM). These early studies, conducted with BrdU- and 14C-thymidine-labelled chromosomes via detection of the Br and 28CN- (14C14N-> labelcarrying signals, provided some evidence for the condensation of the label into banding patterns along the chromatids (SIMS bands) reminiscent of the well known Q- and G-bands obtained by conventional staining methods for optical microscopy. The potential of this technique has been greatly enhanced by the recent upgrade of the UC SIM, now coupled to a high performance magnetic sector mass spectrometer in lieu of the previous RF quadrupole mass filter. The high transmission of the new spectrometer improves the SIMS analytical sensitivity of the microprobe better than a hundredfold, overcoming most of the previous imaging limitations resulting from low count statistics.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Müjgan Ercan Karadağ ◽  
Emiş Deniz Akbulut ◽  
Esin Avcı ◽  
Esra Fırat Oğuz ◽  
Saadet Kader ◽  
...  

AbstractObjectiveHemoglobinopathies are a common public health problem in Turkey. In the screening of these disorders in population, cation-exchange high performance liquid chromatography (HPLC) is accepted as the gold standard method. In this study, the aim was to assess four different HPLC devices used in hemoglobinopathy screening.Materials and methodsA total of 58 blood samples were analyzed with four different HPLC methods (Bio-Rad variant II, Agilent 1100, Tosoh G8 and Trinity Ultra2 trademarks).ResultsThe comparison study demonstrated a good correlation between the results of each HPLC analyzer and the reference value obtained by averaging all the HbA2 results belonging to the methods tested in the study [ (Tosoh G8 (r=0.988), Bio-Rad variant II (r=0.993), Agilent 1100 (r=0.98) and Trinity Ultra2 (r=0.992) ]. HbA2 determination in the presence of HbE was interfered in both Bio-Rad variant II and Tosoh G8.ConclusionThe analyzers were found to have compatible HbA2 results but with accompanying different degrees of proportional and systematic biases. HPLC analyzers may be affected by different hemoglobin variants at different HbA2 concentrations, which is an important point to take into consideration during the evaluation of HbA2 results in thalassemia screening.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Alina Concepción Alvarez ◽  
Ivette Camayd Viera ◽  
Lisy Vento Buigues ◽  
Yanet Fernández Martínez ◽  
Eraida Hernández ◽  
...  

AbstractObjectivesHomocysteine (Hcy) is a nonessential amino acid, produced by the demethylation of methionine. High Hcy levels, or hyperhomocysteinemia, have been associated with genetic and multifactorial diseases. Hcy reference values may vary between different populations, as Hcy levels are affected by factors such as sex, age, diet, smoking, and coffee consumption. The estimation reference interval (RI) allows to establish the normal values of this marker in population. At present, these levels are unknown in Cuba. The aim of this work is to estimate the Hcy reference intervals in Cuban children and adults.MethodsTotal Hcy concentration was quantified by high performance liquid chromatography (HPLC) in plasma. Hcy levels were evaluated in samples from 507 healthy individuals (260 children, 247 adults).ResultsRIs were estimated by nonparametric methods. We found significant differences between both age groups, but we did not find significant differences between sexes, within these groups. The established ranges were 2.56–14.55 µM and 3.63–17.19 µM for children and adults, respectively. Also, we observed a weak association between Hcy levels and age in both sex groups.ConclusionsThis is the first study that assesses Hcy reference values in Cuban population. Our results will allow the introduction of Hcy as a biochemical marker in laboratory testing.


2019 ◽  
Vol 485 (3) ◽  
pp. 3370-3377 ◽  
Author(s):  
Lehman H Garrison ◽  
Daniel J Eisenstein ◽  
Philip A Pinto

Abstract We present a high-fidelity realization of the cosmological N-body simulation from the Schneider et al. code comparison project. The simulation was performed with our AbacusN-body code, which offers high-force accuracy, high performance, and minimal particle integration errors. The simulation consists of 20483 particles in a $500\ h^{-1}\, \mathrm{Mpc}$ box for a particle mass of $1.2\times 10^9\ h^{-1}\, \mathrm{M}_\odot$ with $10\ h^{-1}\, \mathrm{kpc}$ spline softening. Abacus executed 1052 global time-steps to z = 0 in 107 h on one dual-Xeon, dual-GPU node, for a mean rate of 23 million particles per second per step. We find Abacus is in good agreement with Ramses and Pkdgrav3 and less so with Gadget3. We validate our choice of time-step by halving the step size and find sub-percent differences in the power spectrum and 2PCF at nearly all measured scales, with ${\lt }0.3{{\ \rm per\ cent}}$ errors at $k\lt 10\ \mathrm{Mpc}^{-1}\, h$. On large scales, Abacus reproduces linear theory better than 0.01 per cent. Simulation snapshots are available at http://nbody.rc.fas.harvard.edu/public/S2016.


1998 ◽  
Vol 514 ◽  
Author(s):  
D. Edelstein

ABSTRACTRecently IBM announced the first implementation of full copper ULSI wiring in a CMOS technology, to be manufactured on its high-performance 0.22 um CMOS products this year. Features of this technology will be presented, as well as functional verification on CMOS chips. To reach this level, extensive yield, reliability, and stress testing had to be done on test and product-like chips, including those packaged into product modules. Data will be presented fom all aspects of this testing, ranging from experiments designed to promote Cu contamination of the MOS devices, to temperature/humidity/bias stressing of assembled functional modules. The results in all areas are shown to be equal to or better than standards set by our current AI(Cu)/Wstud technology. This demonstrates that the potential problems associated with copper wiring that have long been discussed can be overcome.


Author(s):  
P. Laurent ◽  
F. Acero ◽  
V. Beckmann ◽  
S. Brandt ◽  
F. Cangemi ◽  
...  

AbstractBased upon dual focusing techniques, the Polarimetric High-Energy Modular Telescope Observatory (PHEMTO) is designed to have performance several orders of magnitude better than the present hard X-ray instruments, in the 1–600 keV energy range. This, together with its angular resolution of around one arcsecond, and its sensitive polarimetry measurement capability, will give PHEMTO the improvements in scientific performance needed for a mission in the 2050 era in order to study AGN, galactic black holes, neutrons stars, and supernovae. In addition, its high performance will enable the study of the non-thermal processes in galaxy clusters with an unprecedented accuracy.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hang Li ◽  
Jiamin Liu ◽  
Zhanzhong Wang ◽  
Xiaodong Liu ◽  
Xichun Yan ◽  
...  

Abstract With chili and liquid beef tallow as the main raw materials, the processing conditions of chili flavor beef tallow were explored. Gas chromatograpy-ion mobility spectrometry (GC-IMS) was used to determine the volatile compounds in chili flavor beef tallow. The capsaicin and dihydrocapsaicin in chili flavor beef tallow were determined by high performance liquid chromatography (HPLC). The optimum technological conditions were determined, and the index of chromatic aberration, cholesterol was also determined. Based on GC-IMS analysis, 102 kinds of volatile compounds were detected, and the sample III (the ratio of solid–liquid was 1:5, the frying temperature was 120 °C, and the frying time was 15 min) performed better than other samples. The preparation of chili beef tallow improves its antioxidant activity and makes its aroma more intense and more in line with the taste of Chinese people, which provides a theoretical and practical basis for the development of spice beef tallow in the future.


2006 ◽  
Vol 290 (5) ◽  
pp. H1818-H1825 ◽  
Author(s):  
Lisa M. Smyth ◽  
Leanne T. Breen ◽  
Violeta N. Mutafova-Yambolieva

Using high-performance liquid chromatography techniques with fluorescence and electrochemical detection, we found that β-nicotinamide adenine dinucleotide (β-NAD) is released in response to electrical field stimulation (4–16 Hz, 0.3 ms, 15 V, 120 s) along with ATP and norepinephrine (NE) in the canine isolated mesenteric arteries. The release of β-NAD increases with number of pulses/stimulation frequencies. Immunohistochemistry analysis showed dense distribution of tyrosine hydroxylase-like immunoreactivity (TH-LI) and sparse distribution of TH-LI-negative nerve processes, suggesting that these blood vessels are primarily under sympathetic nervous system control with some contribution of other (e.g., sensory) neurons. Exogenous NE (3 μmol/l), α,β-methylene ATP (1 μmol/l), neuropeptide Y (NPY, 0.1 μmol/l), CGRP (0.1 μmol/l), vasoactive intestinal peptide (VIP, 0.1 μmol/l), and substance P (SP, 0.1 μmol/l) had no effect on the basal release of β-NAD, suggesting that the overflow of β-NAD is evoked by neither the sympathetic neurotransmitters NE, ATP, and NPY, nor the neuropeptides CGRP, VIP, and SP. Botulinum neurotoxin A (BoNTA, 0.1 μmol/l) abolished the evoked release of NE, ATP, and β-NAD at 4 Hz, suggesting that at low levels of neural activity, release of these neurotransmitters results from N-ethylmaleimide-sensitive factor attachment protein receptor/synaptosomal-associated protein of 25 kDa-mediated exocytosis. At 16 Hz, however, the evoked release of NE, ATP, and β-NAD was reduced by BoNTA by ∼90, 60, and 80%, respectively, suggesting that at higher levels of neural activity, β-NAD is likely to be released from different populations of synaptic vesicles or different populations of nerve terminals (i.e., sympathetic and sensory terminals).


2021 ◽  
Author(s):  
Lucas Bragança ◽  
Jeronimo Penha ◽  
Michael Canesche ◽  
Dener Ribeiro ◽  
José Augusto M. Nacif ◽  
...  

FPGAs are suitable to speed up gene regulatory network (GRN) algorithms with high throughput and energy efficiency. In addition, virtualizing FPGA using hardware generators and cloud resources increases the computing ability to achieve on-demand accelerations across multiple users. Recently, Amazon AWS provides high-performance Cloud's FPGAs. This work proposes an open source accelerator generator for Boolean gene regulatory networks. The generator automatically creates all hardware and software pieces from a high-level GRN description. We evaluate the accelerator performance and cost for CPU, GPU, and Cloud FPGA implementations by considering six GRN models proposed in the literature. As a result, the FPGA accelerator is at least 12x faster than the best GPU accelerator. Furthermore, the FPGA reaches the best performance per dollar in cloud services, at least 5x better than the best GPU accelerator.


Author(s):  
Bryan J Starkey ◽  
Ian D R Fry

A new commercial enzymic kit for urinary oxalate determination has been adapted for use on a centrifugal analyser. It has been evaluated and compared with an established high performance liquid chromatographic (HPLC) procedure developed in our laboratory. Mean recovery of oxalate from urine samples augmented with oxalic acid exceeded 97% by both methods. The precision of the HPLC method was superior to that of the enzymic kit but both methods gave between batch precision values better than CV 12% at low (less than 100μmol/L) oxalate concentrations and better than CV 7% at higher concentrations (greater than 270μmol/L) Urinary oxalate values obtained with the new enzymic procedure correlated more closely with HPLC values ( r = 0·84) than did values previously obtained using the forerunner of the kit ( r = 0·62) which was known to be susceptible to ascorbate interference. No significant interference from ascorbic acid or from high urinary calcium concentrations could be demonstrated using either the improved kit or the HPLC procedure. Its easy adaptation to automated analysers available in most laboratories, coupled to its acceptable analytical performance render the enzymic kit a reasonable alternative to HPLC or other more complex procedures for urinary oxalate analysis.


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