Finite-temperature single molecule vibrational dynamics from combined density functional tight binding extended lagrangian dynamics simulations and time series analysis

Combining a computationally efficient and affordable molecular dynamics approach, based on atom-centered density matrix propagation scheme, with the density functional tight binding semiempirical quantum mechanics, we study the vibrational dynamics of a single molecule at series of finite temperatures, spanning quite wide range. Data generated by molecular dynamics simulations are further analyzed and processed using time series analytic methods, based on correlation functions formalism, leading to both vibrational density of states spectra and infrared absorption spectra at finite temperatures. The temperature-induced dynamics in structural intramolecular parameters is correlated to the observed changes in the spectral regions relevant to molecular detection. In particular, we consider a case when an intramolecular X-H stretching vibrational states are notably dependent on the intramolecular torsional degree of freedom, the dynamics of which is, on the other hand, strongly temperature-dependent.publishedVersio

Laser-Induced Graphene for Heartbeat Monitoring with HeartPy Analysis

The HeartPy Python toolkit for analysis of noisy signals from heart rate measurements is an excellent tool to use in conjunction with novel wearable sensors. Nevertheless, most of the work to date has focused on applying the toolkit to data measured with commercially available sensors. We demonstrate the application of the HeartPy functions to data obtained with a novel graphene-based heartbeat sensor. We produce the sensor by laser-inducing graphene on a flexible polyimide substrate. Both graphene on the polyimide substrate and graphene transferred onto a PDMS substrate show piezoresistive behavior that can be utilized to measure human heartbeat by registering median cubital vein motion during blood pumping. We process electrical resistance data from the graphene sensor using HeartPy and demonstrate extraction of several heartbeat parameters, in agreement with measurements taken with independent reference sensors. We compare the quality of the heartbeat signal from graphene on different substrates, demonstrating that in all cases the device yields results consistent with reference sensors. Our work is a first demonstration of successful application of HeartPy to analysis of data from a sensor in development

Wearable Patch for Mass Casualty Screening with Graphene Sensors

Wearable sensors are reaching maturity, at the same time as technologies for communicating physiological data and those for analyzing massive amounts of data. The combination of the three technologies invites for applications in mass screening of personal health through smart algorithm deployment on data from wearable patches. We propose and present an architecture for a wearable patch to be used in mass casualty emergency situations, or for hospital bedside monitoring. The proposed patch will contain multiple sensors of physiological parameters. We propose to create respiration and heartbeat sensors made of laser induced graphene. We show that graphene on flexible substrates can be utilized in conjunction with the Python heart rate analysis toolkit - HeartPy to reliably acquire physiological data from human subject

Finite-Temperature Single Molecule Vibrational Dynamics from Combined Density Functional Tight Binding Extended Lagrangian Dynamics Simulations and Time Series Analysis

Combining a computationally efficient and affordable molecular dynamics approach, based on atom-centered density matrix propagation scheme, with the density functional tight binding semiempirical quantum mechanics, we study the vibrational dynamics of a single molecule at series of finite temperatures, spanning quite wide range. Data generated by molecular dynamics simulations are further analyzed and processed using time series analytic methods, based on correlation functions formalism, leading to both vibrational density of states spectra and infrared absorption spectra at finite temperatures. The temperature-induced dynamics in structural intramolecular parameters is correlated to the observed changes in the spectral regions relevant to molecular detection. In particular, we consider a case when an intramolecular X-H stretching vibrational states are notably dependent on the intramolecular torsional degree of freedom, the dynamics of which is, on the other hand, strongly temperature-dependent.publishedVersio

Windows Azure: Resource Organization Performance Analysis

International audienceCloud customers can scale the resources according to their needs in order to avoid application bottleneck. The scaling can be done in two ways, either by increasing the existing virtual machine instance with additional resources, or by adding an additional virtual machine instance with the same resources. Although it is expected that the costs rise proportionally to scaling, we are interested in finding out which organization offers scaling with better performance. The goal of this paper is to determine the resource organization that produces better performance for the same cost, and help the customers decide if it is better to host a web application on a more ”small” instances or less ”large” instances. The first hypothesis states that better performance is obtained by using more and smaller instances. The second hypothesis is that the obtained speedup while scaling the resources is smaller than the scaling factor. The results from the provided experiments have not proven any of the hypotheses, meaning that using less, but larger instances results with better performance and that the user gets more performances than expected by scaling the resources

Blood Oxygen Saturation Estimation with Laser-Induced Graphene Respiration Sensor

Measuring blood oxygen saturation (SpO2) is crucial in a triage process for identifying patients with respiratory distress or shock, since low SpO2 levels indicate compromised hemostability and the need for priority treatment. This paper explores the use of wearable mechanical deflection sensors based on laser-induced graphene (LIG) for SpO2 estimation. The LIG sensors are attached to a subject's chest for real-Time monitoring of respiratory signals. We have developed a novel database of the respiratory signals, with corresponding SpO2 values ranging from 86% to 100%. The database is used to develop an artificial neural network model for SpO2 estimation. The neural network performance is promising, with regression metrics mean squared error = 0.184, mean absolute error = 0.301, root mean squared error = 0.429, and R-squared = 0.804. The use of mechanical respiration sensors in combination with neural networks in biosensing opens new possibilities for noninvasive SpO2 monitoring and other innovative applications. © 2024 Ana Madevska Bogdanova et al

Continuous Vital Parameters Monitoring by Using Biosensors and Smart Technology Solution

In this paper we present wireless solution for continuous monitoring of vital parameters by using the leverage of both the biosensors and the smart technology. The proposed solution consists of three commercially available biomedical sensors and a portable smart technology device. The integration allows continuous capture of the heart rate, respiratory rate, part-time blood pressure and oxygen saturation. The application enables insight into the recent history of the parameters, additionally providing information of the shock index, Glasgow comma scale score and the hemodynamic stability of the patient. The solution is suitable for pre-hospital, during the vehicle transport and in-hospital environment. Given all the hardware used is commercially available, the integration is highly cost effective when compared to the hospital equipment. The reliability has been tested in hospital environment