Chest‐Laminated and Sweat‐Permeable E‐Skin for Speech and Motion Artifact‐Insensitive Cough Detection

Assessment of the cough severity is essential when dealing with respiratory diseases such as chronic obstructive pulmonary disease and COVID‐19. Although a few wearable devices have been reported for cough detection, they mostly rely on microphones, accelerometers, or throat‐fixed flexible sensors, which suffer from key issues including privacy disclosure and speech/motion artifacts. This study presents a chest‐laminated electronic skin (e‐skin) for reliable cough detection. Mixed dumbbell‐like networks and through‐holes are engineered on hard‐to‐stretch composite films for high stretching force sensitivity and sweat permeation, respectively. The e‐skin can effectively reduce speech‐signal and motion artifacts owing to firm adhesion and conformal contact with the chest even on sweaty skin. Experimental results show that the specificity for cough identification is as high as 99.75% through machine learning of automated acoustic analysis, even in the presence of hard‐to‐distinguish daily activities such as throat clearing. The developed chest‐laminated e‐skin is a simple, comfortable, yet reliable method to detect cough for the primary diagnosis of respiratory diseases by extracting subtle acoustic information from cough. [ABSTRACT FROM AUTHOR] Copyright of Advanced Materials Technologies is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An IoT-enabled Electronic Textile-based Flexible Body Sensor Network for Real-time Health Monitoring in Assisted Living during Pandemic

This paper presents a cost-effective and flexible electronic textile sensor with high sensitivity and fast response and demonstrates its versatile applications, including real-time measurements of finger kinematics, phonation, cough patterns, as well as subtle muscle movements (i.e., eye reflex). The sensor can discriminate between speech and cough patterns, thereby expanding its applications to COVID-19 detection, speech rehabilitation training, and human/machine interactions. A combination of different sensor data is essential to acquire clinically significant information. Therefore, a sensor array is interfaced with the LoRa communication protocol to establish an Internet of Things (IoT)-based electronic textile framework. The IoT integration allows remote monitoring of body kinematics and physiological parameters. Therefore, the proposed IoT-based framework holds the potential to provide real-time and continuous health monitoring to allow immediate intervention during this pandemic. © 2022 IEEE.

Intelligent Nanomaterials for Wearable and Stretchable Strain Sensor Applications: The Science behind Diverse Mechanisms, Fabrication Methods, and Real-Time Healthcare.

It has become a scientific obligation to unveil the underlying mechanisms and the fabrication methods behind wearable/stretchable strain sensors based on intelligent nanomaterials in order to explore their possible potential in the field of biomedical and healthcare applications. This report is based on an extensive literature survey of fabrication of stretchable strain sensors (SSS) based on nanomaterials in the fields of healthcare, sports, and entertainment. Although the evolution of wearable strain sensors (WSS) is rapidly progressing, it is still at a prototype phase and various challenges need to be addressed in the future in special regard to their fabrication protocols. The biocalamity of COVID-19 has brought a drastic change in humans' lifestyles and has negatively affected nations in all capacities. Social distancing has become a mandatory rule to practice in common places where humans interact with each other as a basic need. As social distancing cannot be ruled out as a measure to stop the spread of COVID-19 virus, wearable sensors could play a significant role in technologically impacting people's consciousness. This review article meticulously describes the role of wearable and strain sensors in achieving such objectives.

E-MASK: A Mask-Shaped Interface for Silent Speech Interaction with Flexible Strain Sensors

We present E-MASK, a mask-shaped interface for silent speech interaction. As face masks have become daily accessories since the COVID-19 pandemic, it is reasonable to utilize a mask as a wearable interface. Unlike conventional speech recognition, we envision that silent speech interaction allows users to access digital services even in crowded public spaces. With flexible and highly sensitive strain sensors, E-MASK presents a new measurement principle for silent speech interactions. We built a dataset of sensor patterns corresponding to 21 fundamental commands of Alexa's operation. All commands were silently spoken by five non-native English speakers. The dataset was used to estimate the silently spoken commands. Estimation accuracies of 84.4% while sitting on a chair and 79.1% while walking on a treadmill were archived. This result suggests that our system provides seamless interaction with digital devices in various situations in daily life, such as walking in a crowd. © 2022 Owner/Author.

Highly sensitive and stretchable piezoelectric strain sensor enabled wearable devices for real-time monitoring of respiratory and heartbeat simultaneously

The World Health Organization has declared COVID-19 a pandemic. The demand for devices or systems to diagnose and track COVID-19 infections noninvasively not only in hospitals but also in home settings has led to increased interest in consumer-grade wearables. A common symptom of COVID-19 is dyspnea, which may manifest as an increase in respiratory and heart rates. In this paper, a novel piezoelectric strain sensor is presented for real-time monitoring of respiratory and heartbeat signals. A highly sensitive and stretchable piezoelectric strain sensor is fabricated using a piezoelectric film with a serpentine layout. The thickness of the patterned PVDF flexible piezoelectric strain sensor is only 168 μm, and the voltage sensitivity reaches 0.97 mV/μɛ. The effective modulus is 13.5 MPa, which allows the device to fit to the skin and detect the small strain exhibited by the human body. Chest vibrations are captured by the piezoelectric sensor, which produces an electrical output voltage signal conformally mapped with respiratory-cardiac activities. The separate heart activity and respiratory signals are extracted from the mixed respiratory-cardiac signal by an empirical mode decomposition data processing algorithm. By detecting vital signals such as respiratory and heart rates, the proposed device can aid early diagnosis and monitoring of respiratory diseases such as COVID-19. © 2022 Author(s).

CNT/Graphite/SBS Conductive Fibers for Strain Sensing in Wearable Telerehabilitation Devices.

Rapid growth of personal electronics with concurrent research into telerehabilitation solutions discovers opportunities to redefine the future of orthopedic rehabilitation. After joint injury or operation, convalescence includes free active range of movement exercises, such as joints bending and straightening under medical supervision. Flexion detection through wearable textile sensors provides numerous potential benefits such as: (1) reduced cost; (2) continuous monitoring; (3) remote telerehabilitation; (4) gamification; and (5) detection of risk-inducing activities in daily routine. To address this issue, novel piezoresistive multi-walled carbon nanotubes/graphite/styrene-butadiene-styrene copolymer (CNT/Gr/SBS) fiber was developed. The extrusion process allowed adjustable diameter fiber production, while being a scalable, industrially adapted method of manufacturing textile electronics. Composite fibers were highly stretchable, withstanding strains up to 285%, and exhibited exceptional piezoresistive parameters with a gauge factor of 91.64 for 0-100% strain range and 2955 for the full scope. Considering the composite's flexibility and sensitivity during a series of cyclic loading, it was concluded that developed Gr/CNT/SBS fibers were suitable for application in wearable piezoresistive sensors for telerehabilitation application.