A Low-Cost Wearable Device to Estimate Body Temperature Based on Wrist Temperature.

The remote monitoring of vital signs and healthcare provision has become an urgent necessity due to the impact of the COVID-19 pandemic on the world. Blood oxygen level, heart rate, and body temperature data are crucial for managing the disease and ensuring timely medical care. This study proposes a low-cost wearable device employing non-contact sensors to monitor, process, and visualize critical variables, focusing on body temperature measurement as a key health indicator. The wearable device developed offers a non-invasive and continuous method to gather wrist and forehead temperature data. However, since there is a discrepancy between wrist and actual forehead temperature, this study incorporates statistical methods and machine learning to estimate the core forehead temperature from the wrist. This research collects 2130 samples from 30 volunteers, and both the statistical least squares method and machine learning via linear regression are applied to analyze these data. It is observed that all models achieve a significant fit, but the third-degree polynomial model stands out in both approaches. It achieves an R2 value of 0.9769 in the statistical analysis and 0.9791 in machine learning.

A theoretical and experimental investigation on a volume coil with slotted end-rings for rat MRI at 7 T.

OBJECTIVE: A volume coil with squared slots-end ring was developed to attain improved sensitivity for imaging of rat's brain at 7 T. MATERIAL AND METHODS: The principles of the high cavity resonator for the low-pass case and the law of Biot-Savart were used to derive a theoretical expression of [Formula: see text]. The slotted-end ring resonator showed a theoretical 2.22-fold sensitivity improvement over the standard birdcage coil with similar dimensions. Numerical studies were carried out for the electromagnetic fields and specific absorption rates for our coil and a birdcage coil loaded with a saline-filled spherical phantom and a digital brain of a rat. RESULTS: An improvement of the signal-to-noise ratio (SNR) can be observed for the slotted volume coil over the birdcage regardless of the load used in the electromagnetic simulations. The specific absorption rate simulations show a decrement for the digital brain and quite similar values with the saline solution phantom. Phantom and rat's brain images were acquired at 7 T to prove the viability of the coil design. The experimental noise figure of our coil design was four times less than the standard birdcage with similar dimensions, which showed a 44.5% increase in experimental SNR. DISCUSSION: There is remarkable agreement among the theoretical, numerical and experimental sensitivity values, which all demonstrate that the coil performance for MR imaging of small rodents can be improved using slotted end-rings.

Time to a Negative SARS-CoV-2 PCR Predicts Delayed Return to Work After Medical Leave in COVID-19 Infected Health Care Workers.

OBJECTIVE: To investigate whether HCWs return to work (RTW) after COVID-19 was associated with time to a negative viral detection test. METHODS: To evaluate the association of RTW with an undetectable RT-PCR adjusting for different factors. RESULTS: Three hundred seventy-five HCWs who required medical leave for COVID-19 at a hospital in Madrid. Multivariable analyses confirmed the association of delayed RTW with interval to negative PCR (ORadj 1.12, 95% CI 1.08, 1.17) as well as age, sex, and nursing staff and clinical support services compared to physicians. A predictive model based on those variables is proposed, which had an area under the receiver operating curve of 0.82. CONCLUSIONS: Delayed RTW was associated with longer interval to a negative RT-PCR after symptom onset, adjusting for occupational category, age, and sex.

Design and Implementation of the E-Switch for a Smart Home.

As the development of systems in smart homes is increasing, it is of ever-increasing importance to have data, which artificial intelligence methods and techniques can apply to recognize activities and patterns or to detect anomalies, with the aim of reducing energy consumption in the main home domestic services, and to offer users an alternative in the management of these resources. This paper describes the design and implementation of a platform based on the internet of things and a cloud environment that allows the user to remotely control and monitor Wi-Fi wireless e-switch in a home through a mobile application. This platform is intended to represent the first step in transforming a home into a smart home, and it allows the collection and storage of the e-switch information, which can be used for further processing and analysis.

Surface coil with reduced specific absorption rate for rat MRI at 7 T.

OBJECTIVE: A scaled-down slotted surface radio frequency (RF) coil was built, and the specific absorbance rate (SAR) in 100 mg of tissue (SAR100 mg) produced in a rat brain phantom was computed at 7 T. MATERIALS AND METHODS: A slotted coil 2-cm in diameter with six circular slots was developed. Its theoretical and experimental performance was computed and compared using the signal-to-noise ratio (SNR) expression and phantom images obtained with a spin echo sequence. Electromagnetic simulations were performed using the finite integral method with saline sphere and rat brain phantoms. SAR100 mg was computed for the circular coil, by varying its radius, and was also computed for the slotted coil. RESULTS: The slotted coil quality factor gave a twofold increment over the circular coil, and noise was reduced by 17%. The experimental SNR of the slotted coil produced a 30% improvement for points near the coil plane. The theoretical and experimental results showed substantial agreement. Axial map histograms and profiles showed greater SAR100 mg values for the circular coil than for the slotted coil. CONCLUSIONS: The slotted surface coil offers improved performance and low SAR100 mg for rat brain imaging at 7 T. This approach may be used with new RF coils to investigate SAR in humans.