Prospective Evaluation of the Transparent, Elastomeric, Adaptable, Long-Lasting (TEAL) Respirator
N95 filtering facepiece respirators (FFR) and surgical masks are essential in reducing airborne disease transmission, particularly during the COVID-19 pandemic. However, currently available FFR’s and masks have major limitations, including masking facial features, waste, and integrity after decontamination. In a multi-institutional trial, we evaluated a transparent, elastomeric, adaptable, long-lasting (TEAL) respirator to evaluate success of qualitative fit test with user experience and biometric evaluation of temperature, respiratory rate, and fit of respirator using a novel sensor. There was a 100% successful fit test among participants, with feedback demonstrating excellent or good fit (90% of participants), breathability (77.5%), and filter exchange (95%). Biometric testing demonstrated significant differences between exhalation and inhalation pressures among a poorly fitting respirator, well-fitting respirator, and the occlusion of one filter of the respirator. We have designed and evaluated a transparent elastomeric respirator and a novel biometric feedback system that could be implemented in the hospital setting.
Electronics for Transparent, Long-Lasting Respirators
The use of Personal Protective Equipment (PPE), including the N95 respirators and surgical masks, are essential in reducing airborne disease transmission, particularly during the COVID-19 pandemic. Unfortunately, there has been a shortage of PPE since the beginning of the pandemic. Also, available N95 masks have major limitations, including masking facial features, waste, and integrity after decontamination, forcing researchers to find alternatives. This work presents a transparent, elastomeric, adaptable, long-lasting respirator with an integrated biometric interface. The mask is mostly made out of silicon rubber and comes with two replaceable filter cartridges. The electronic interface uses one of the filter insert locations to measure temperature, humidity, pressure, and air quality. The system uses BLE and sends real-time sensor data to a phone or a computer. The data can be used to inform the user regarding mask fit, fatigue, mask condition, and potential diagnostic information.
Rapid Monitoring of Sepsis Using Microfluidics
Sepsis is the dysregulated response to infection, and a major health burden worldwide. Septic patients are commonly monitored by clinical criteria and peripheral blood leukocyte counts; however, monitoring leukocyte counts does not reliably reflect patients’ clinical and treatment responses. A major need, therefore, is the development of a device that can rapidly and reliably measure the functional state of the immune system, and in particular the polymorphonuclear neutrophils (PMN) that mediate much of the clinical response. Isodielectric separation (IDS) uses dielectrophoresis (DEP) to determine an electrical signature for PMNs that distinguishes resting from activated cells without any exogenous labels. Here we show the first clinical application of DEP, specifically that electrical phenotyping correlates with clinical severity scores better than leukocyte counts (r = -0.23, not shown), and therefore holds promise for rapid label-free monitoring of sepsis progression. Further, we integrate IDS with a multi-dimensional double spiral (MDDS) inertial separation platform to develop a fully-automated integrated platform for label-free and rapid measurement of PMNs from microliter quantities of human peripheral blood.
A Sample-to-Answer Electrochemical System for Point-of-Care Biomarker Detection
The detection of protein biomarkers is a powerful tool for the diagnosis and treatment of various diseases. Typically, the quantification and analysis of biomarkers from blood samples is completed in centralized laboratories through bulky and expensive analyzers. This results in long turnaround times and higher healthcare costs, which can worsen patient outcomes. Here, we present a sample-to-answer Point-of-Care (POC) platform for the rapid detection of protein biomarkers. This POC system integrates on-chip whole blood to plasma separation, bead-based biomarker capture, microfluidic handling and electronic readout into an automated 30-minute assay. We demonstrate the full sample-to-answer workflow through the detection of clinically relevant concentrations of interleukin-6 (IL-6), a marker of numerous diseases. These results suggest that this POC platform can be used for the sensitive and rapid measure of biomarkers for disease diagnostics and monitoring.
SonicPACT: An Ultrasonic Ranging Method for the Private Automated Contact Tracing (PACT) Protocol
Throughout the course of the COVID-19 pandemic, several countries have developed and released contact tracing and exposure notification smartphone apps to help slow the spread of the disease. To allow for privacy preserving contact discovery, Apple and Google have released Exposure Notification Application Programming Interfaces (APIs) to infer device (user) proximity using Bluetooth Low Energy (BLE). Unfortunately, accurately estimating the distance between devices using only BLE signal strength is difficult and prone to errors. This presentation will describe the SonicPACT, a protocol to use near-ultrasonic acoustic signals on commodity iOS and Android smartphones to estimate inter-device distances. The protocol allows Android and iOS devices to inter-operate, augmenting and improving the current exposure notification APIs. Our initial experimental results are promising, suggesting that SonicPACT should be considered for implementation by Apple and Google.
Highly integrated bioelectronic system based on graphene transistor arrays for multiple ion detection
High-accuracy, real-time ion sensing is of great interest to the biomedical research and industry, where high throughput bio-related data is critical for accurate disease diagnosis. However, current technology suffers from strong device-to-device variability, reproducibility and reliability. Here, we develop a robust bioelectronic sensing platform made with more than 200 integrated sensing units, custom-built high-speed readout electronics, and machine learning inference for rapid and portable measurement. The platform demonstrates reconfigurable multi-ion electrolyte sensing capability and provides highly sensitive, reversible, and timely response for potassium, sodium, and calcium ions. Leveraging the large dataset and multi-dimensional information collected through the multiplexed sensor array, statistical analysis and machine learning algorithm are applied to enhance ion classification accuracy in complexed mixtures with different ion concentrations.
Far UV-C light-emitting diode based on hexagonal Boron Nitride for high efficiency sanitizing
Deep ultra-violet (UV) light exposure for a certain amount of time and dose is an efficient method to kill most kinds of viruses and sanitize items. Typical UV light-emitting diodes (LEDs) used in these applications are limited to emission wavelengths larger than 270 nm (UV-A and UV-B), which are harmful for human tissues and could cause potential damages to skin and even trigger cancers. Far UV-C light, on the contrary, with a wavelength of ~210 nm can efficiently kill viruses on the human skin, items, and clothes without penetrating the epidermis or causing damage to humans. However, high-efficiency UV-C LEDs have not been demonstrated yet, since they require extremely large band-gap (> 5.6 eV) materials to realize the emission of UV-C light and the corresponded quantum well structure and doping are also difficult to realize. In this work, we proposed a novel method to fabricate UV-C LED for high efficiency sanitizing based on monolayer hexagonal boron nitride (h-BN), which has a band gap of ~ 5.9 eV and a corresponded wavelength of ~210 nm. By contact work function modulation induced by small molecule dipoles, we realize relatively high carrier injection efficiency with type-II heterojunctions for both electrons and holes, and consequently light-emission. The proposed devices can provide high-efficiency sanitizing for not only fighting the COVID-19 pandemic but also for other applications which require fast disinfection without damaging human tissues, and could pave the way for new surgical equipment.