Wearable Health Monitoring Systems Research Articles

HOT Watch: IoT-Based Wearable Health Monitoring System

HOT Watch: IoT-Based Wearable Health Monitoring System

Nanograting-assisted flexible Triboelectric Nanogenerator for active human motion detection

This manuscript presents the development of a nanograting assisted Triboelectric Nanogenerator (TENG) for improved performance. The TENG leverages a cost-effective and straightforward fabrication method, utilizing nano-gratings on a Polydimethylsiloxane (PDMS) layer to enhance the triboelectric effect. The device characteristics are evaluated by considering tapping force, separation distance, and load resistance. The experimental electrical characterization shows that the output voltage increases significantly with higher applied forces, with a 2N force generating voltage increases of over 584% compared to a 0.1N force. Conversely, the output voltage decreases as the separation distance is reduced. The charge storage capability of the proposed device is demonstrated by integrating a TENG with a full-wave bridge rectifier. Furthermore, the fabricated TENG demonstrates remarkable sensitivity in detecting various body motions. When strategically placed on the biceps, the TENG effectively tracks muscle contraction and expansion with a voltage range of +0.5V to -1V, exhibiting a sensitivity of 1.5V per cycle. Similarly, the TENG accurately detects bending movements in the knee and elbow joints. For knee bending, the voltage output ranges from +2.5V to -1V, resulting in a sensitivity of 3.5V per cycle. Elbow flexion generates voltages between +4V and -5V, corresponding to a sensitivity of 9V per cycle. This clear correlation between voltage and specific body movements makes the TENG a promising candidate for wearable health and motion monitoring systems.

Biomaterials for reliable wearable health monitoring: Applications in skin and eye integration

Recent advancements in biomaterials have significantly impacted wearable health monitoring, creating opportunities for personalized and non-invasive health assessments. These developments address the growing demand for customized healthcare solutions. Durability is a critical factor for biomaterials in wearable applications, as they must withstand diverse wearing conditions effectively. Therefore, there is a heightened focus on developing biomaterials that maintain robust and stable functionalities, essential for advancing wearable sensing technologies. This review examines the biomaterials used in wearable sensors, specifically those interfaced with human skin and eyes, highlighting essential strategies for achieving long-lasting and stable performance. We specifically discuss three main categories of biomaterials—hydrogels, fibers, and hybrid materials—each offering distinct properties ideal for use in durable wearable health monitoring systems. Moreover, we delve into the latest advancements in biomaterial-based sensors, which hold the potential to facilitate early disease detection, preventative interventions, and tailored healthcare approaches. We also address ongoing challenges and suggest future directions for research on material-based wearable sensors to encourage continuous innovation in this dynamic field.

Highly Efficient Back-End-of-Line Compatible Flexible Si-Based Optical Memristive Crossbar Array for Edge Neuromorphic Physiological Signal Processing and Bionic Machine Vision

HighlightsA novel optoelectronic synapse compatible with existing chip technology is demonstrated. This device excels in mimicking memory and learning functions using light, making it ideal for future neuromorphic computing in biomedicine.Our design surpasses previous models with its ability to switch between short-term and long-term memory states using light pulses.Experiments on real-world biomedical data (electroencephalogram, electromyography, electrocardiogram) showed significant improvement in classification accuracy. This highlights the device's potential for advanced physiological signal processing and wearable health monitoring systems.

Effect of Nanostructure Morphology and Concentration on the Piezoelectric Performance of Flexible Pressure Sensor based on PVDFTrFE/ Nano-ZnO Composite Thin Film

Background: The development of high-performance piezoelectric pressure sensors with outstanding sensitivity, good linearity, flexibility, durability, and biocompatibility is of great significance for smart robotics, human healthcare devices, smart sensors, and electronic skin. Thus, considerable progress has been achieved in enhancing the piezoelectric property of PVDF-TrFEbased composite pressure sensors by adding various ZnO nanostructures in PVDF-TrFE polymer acting as a nucleating agent and dielectric material. Aims: In this work, flexible pressure sensors with a sandwich structure based on PVDFTrFE/ nano-ZnO composite sensing film were fabricated using a simple spin-coating method and post-annealing process, while electrospinning and high-voltage polarization processes were not adopted. Methods: Poly (vinylidene fluoride-trifluoroethylene) (PVDF-TrFE)/nano-ZnO composite films were prepared via spin coating to fabricate flexible piezoelectric pressure sensors. ZnO nanoparticles (ZnO NPs), tetrapod ZnO (T-ZnO) and ZnO nanorods (ZnO NRs) were used as nano-fillers for piezoelectric PVDF-TrFE, to enhance the beta-crystal ratio as well as the crystallinity of PVDF-TrFE. The structural and surface morphologies of the composite films were investigated using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results: Among three different types of ZnO nanostructures with a concentration range (0-7.5 wt%), the sensor with 0.75 wt% ZnO NRs nanofiller exhibits a maximum output voltage of 1.73 V under an external pressure of 3 N and a maximum sensitivity of 586.3 mV/N at the range of 0-3 N. Further, the sensor can generate a clear piezoelectric voltage under bending and twisting deformation as well as compression and tensile deformation. Conclusion: To summarize, the addition of different concentrations of nano-ZnO can remarkably improve the piezoelectric performance of the composite sensor, and ZnO NRs can achieve better piezoelectric properties of the sensor as compared to ZnO NPs and T-ZnO. In addition, the sensor with 0.75 wt% ZnO NRs as nanofiller has the highest piezoelectric response, which is about 2.4 times that of the pure PVDF-TrFE sensor. It is demonstrated that the sensor has great potential applications in wearable health monitoring systems and mechanical stress measurement electronics.

YELLOW LIGHT THE NEXT TECHNOLOGY FOR SMART WATCHES

Light emitting diodes (LED) are often found in wearable smart electronic devices, such as smart watches, health care monitoring system etc. These are utilized for photoplethysmography (PPG) to monitor a variety of physical health factors. Wearable health monitoring systems have been developed as an outcome of the growth of sensor-based process to deliver real-time feedback information to promote health. This technique has the potential to help with symptom checking and treatment in sophisticated diseases, such as pain management.

Retracted: Fog-Driven Secure Authentication and Key Exchange Scheme for Wearable Health Monitoring System

Retracted: Fog-Driven Secure Authentication and Key Exchange Scheme for Wearable Health Monitoring System

A new particle filter algorithm filtering motion artifact noise for clean electrocardiogram signals in wearable health monitoring system.

With the evolution of wearable systems, more and more people tend to wear wearable devices for health monitoring during sports. However, a large amount of motion artifact noise is introduced at this time, which is difficult to filter out due to its stochasticity. The amplitude and characteristics of motion artifact noise vary with changes in motion intensity. In order to filter out the motion artifact noise, the paperproposes a new particle algorithm, which can detect the intensity of the motion artifact for adaptive filtering, especiallysuitable for wearable health monitoring systems. In this algorithm, variational mode decomposition was first introduced to analyze the noisy electrocardiogram (ECG) signal in order to find the clean components. Then, the Laguerre estimation technique was applied to obtain an accurate ECG polar model. Taking this model as the state equation, a particle filter algorithm was defined to filter out the motion artifact noise. In the particle filter algorithm, we defined a parameter γ whose values were obtained from the six-axis data of motion sensor MPU6050 in our wearable device. This parameter γ could reflect the current noise levels and adaptively update the particle weights. Finally, some exercise experiments proved that the parameter γ could map the motion artifacts in real time and also demonstrated the superiority of the algorithm in terms of signal-to-noise ratio improvement and error reduction compared to other algorithms. The new particle filter algorithm proposed in this paper combines the six-axis data (three-axis accelerometer and three-axis gyroscope) with the ECG signal to effectively eliminate a large amount of motion artifact noise, thus solving the problem of excess noise from wearable devices when people are exercising, allowing them to accurately obtain real-time ECG health information.

Electromechanical properties of knitted structures for potential socks sensing systems

The use of knitted structure pressure sensors in wearable applications and health monitoring systems has attracted a great deal of attention. This study aims to assess the single jersey and double jersey knitted structures as well as the electromechanical characteristics of electrically conductive yarns (ECY). The knitted structures were made with two different types of electrically conductive yarn, including the (i) fully drawn yarn (FDY) and the (ii) drawn textured yarn (DTY). FDY had higher tensile strength than DTY in reference to their drawing and twisting processes. Based on the results in terms of tensile strength, conductive yarns of 280D-FDY and SPFX25070-FX were chosen from seven available conductive yarns for the further production of knitted structures. Additionally, the knittability of the conductive yarn was also considered. Due to the knit-tuck stitch assembly, which increases the thickness of the structure, it was found that the double Lacoste, popcorn, and milano ribs had the necessary compression resistance. The compression properties of the knitted structures were tested using the kawabata evaluation system (KES FB-03). It was found that the recommended knitted structure sensing technology can be easily expanded into a scalable and affordable solution for the production of smart socks and related applications.

An amorphous Cr2Ge2Te6/polyimide double-layer foil with an extraordinarily outstanding strain sensing ability.

To realize a wearable health monitoring system, a piezoresistive material capable of detecting very small mechanical strains is needed. In this study, an amorphous Cr2Ge2Te6 thin film was deposited on a polyimide film by sputtering, and the piezoresistive properties were investigated. In experiments, the Cr2Ge2Te6/polyimide double-layer foil exhibited an outstanding piezoresistive performance as evidenced by the appearance of self-healing cracks during tensile tests and a remarkably large gauge factor of 60 000 in resistance change measurements. Owing to the self-healing character of cracks, the resistance change is repeatable within a specific strain range. Noteworthily, the double-layer foil is simple to prepare and does not require heat treatment. Furthermore, this double-layer foil was used to fabricate a pressure sensor comprising an extremely simple electrical circuit, and it was deployed on the wrist to monitor the artery pulse signal. As a result, the pressure sensor accurately detected artery pulse waves containing large amounts of information.

Integrating Electronics and Biomedical Applications in 3D Printing Current Progress and Future Possibilities

Biomedical three-dimensional(3D) printing has redefined the landscape of medical practice, facilitating the customization of implants, prosthetics, and medical instruments. The use of 3D printing, also known as additive manufacturing, empowers healthcare professionals to create patient-specific medical solutions that align seamlessly with anatomical complexities. Through the deposition of material layer by layer, 3D printing allows for the fabrication of intricately designed structures with precision and reproducibility. The medical field has witnessed a paradigm shift as personalized implants and prosthetics are tailored to the unique needs of patients, thereby improving functionality and patient outcomes. This review aims to provide a comprehensive analysis of the integration of electronics and biomedical 3D printing. The focus extends beyond individual domains, encapsulating the crossroads where the two converge to form synergistic solutions. Each subsequent section of this review will delve into specific facets, discussing current advances, challenges, and potential future trajectories. From 3D printed medical devices with embedded electronics to wearable health monitoring systems, this review seeks to unearth the emerging landscape of interdisciplinary innovation.

Bioinspired Ultra‐Robust Ionogels Constructed with Soft‐Rigid Confinement Space for Multimodal Monitoring Electronics

AbstractIonogels are compelling materials for flexible hybrid electronics owing to their attractive physical properties and infinite adjustability of chemical structures. However, ionogels must be sufficiently strong to ensure durability, stability, and a wide range of strains in various applications to make electronic systems mechanically compliant. Inspired by the hierarchical structure of multiphase substances in the skin, it is fabricated several transparent (>90%) and ultra‐robust (tensile strength >17 MPa, toughness >40 MJ m−3, and elongation ≈300%) ionogels via in situ polymerization of polymers with the different binding abilities to the ionic liquid by forming soft and rigid confinement space. This strategy can also be applied to other ionic liquids and polymers. Furthermore, the designed ionogel sensors can be used to develop a wearable intelligent health monitoring system capable of monitoring health‐related physiological signals, such as temperature, body tremors, wrist pulse, breathing, and gestures, for predicting and responding to emergencies, which will pave the way for wearable security monitoring technology.

Ultrathin Self-Powered Heavy-Metal-Free Cu-In-Se Quantum Dot Photodetectors for Wearable Health Monitoring.

Mechanically deformable photodetectors (PDs) are key device components for wearable health monitoring systems based on photoplethysmography (PPG). Achieving high detectivity, fast response time, and an ultrathin form factor in the PD is highly needed for next-generation wearable PPG systems. Self-powered operation without a bulky power-supply unit is also beneficial for point-of-care application. Here, we propose ultrathin self-powered PDs using heavy-metal-free Cu-In-Se quantum dots (QDs), which enable high-performance wearable PPG systems. Although the light-absorbing QD layer is extremely thin (∼40 nm), the developed PD exhibits excellent performance (specific detectivity: 2.10 × 1012 Jones, linear dynamic range: 102 dB, and spectral range: 250-1050 nm at zero bias), which is comparable to that of conventional rigid QD-PDs employing thick Pb-chalcogenide QD layers. This is attributed to material and device strategies─materials that include Cu-In-Se QDs, a MoS2-nanosheet-blended poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) hole transport layer, a ZnO nanoparticle electron transport layer, Ag and ITO electrodes, and an ultrathin form factor (∼120 nm except the electrodes) that enable excellent mechanical deformability. These allow the successful application of QD-PDs to a wearable system for real-time PPG monitoring, expanding their potential in the field of mobile bioelectronics.

Highly Sensitive Soft Pressure Sensors for Wearable Applications Based on Composite Films with Curved 3D Carbon Nanotube Structures.

Soft pressure sensors based on 3D microstructures exhibit high sensitivity in the low-pressure range, which is crucial for various wearable and soft touch applications. However, it is still a challenge to manufacture soft pressure sensors with sufficient sensitivity under small mechanical stimuli for wearable applications. This work presents a novel strategy for extremely sensitive pressure sensors based on the composite film with local changes in curved 3D carbon nanotube (CNT) structure via expandable microspheres. The sensitivity is significantly enhanced by the synergetic effects of heterogeneous contact of the microdome structure and changes of percolation network within the curved 3D CNT structure. The finite-element method simulation is used to comprehend the relationships between the sensitivity and mechanical/electrical behavior of microdome structure under the applied pressure. The sensor shows an excellent sensitivity (571.64 kPa-1 ) with fast response time (85ms), great repeatability, and long-term stability. Using the developed sensor, a wireless wearable health monitoring system to avoid carpel tunnel syndrome is built, and a multi-array pressure sensor for realizing a variety of movements in real-time is demonstrated.

Cloud-Assisted Secure and Cost-Effective Authenticated Solution for Remote Wearable Health Monitoring System

Security and privacy are the leading solicitude in cloud computing since users have restricted privilege on the data maintained by distinct service providers at remote locations. The situation becomes more strenuous when a huge amount of data is sensed and produced by wearable devices as it is usually considered more sensitive and heterogeneous. The majority of existing authenticated solutions for such a challenging environment either suffer due to high computation and communication costs or due to the fact that they are susceptible to known cyber threats making them impractical for utilization. Therefore we introduced a cost-effective and secure authenticated scheme for the cloud-assisted remote wearable health monitoring system. Informal security proof is discussed to showcase the security strength of the proposed scheme against known security threats. After that a detailed performance analysis of the proposed scheme with related protocols reveals the fact that it can reduce the computation and communication costs by more than 37% and 40%, respectively. Moreover, our scheme offers some added security features like physical and desynchronization attacks prevention.

Retraction Note: A fuzzy model of wearable network real-time health monitoring system on pharmaceutical industry

Retraction Note: A fuzzy model of wearable network real-time health monitoring system on pharmaceutical industry

Graphene-Based Wearable Temperature Sensors: A Review.

Flexible sensing electronics have received extensive attention for their potential applications in wearable human health monitoring and care systems. Given that the normal physiological activities of the human body are primarily based on a relatively constant body temperature, real-time monitoring of body surface temperature using temperature sensors is one of the most intuitive and effective methods to understand physical conditions. With its outstanding electrical, mechanical, and thermal properties, graphene emerges as a promising candidate for the development of flexible and wearable temperature sensors. In this review, the recent progress of graphene-based wearable temperature sensors is summarized, including material preparation, working principle, performance index, classification, and related applications. Finally, the challenges and future research emphasis in this field are put forward. This review provides important guidance for designing novel and intelligent wearable temperature-sensing systems.

IoT-based wearable health monitoring device and its validation for potential critical and emergency applications.

The COVID-19 pandemic brought the world to a standstill, posing unprecedented challenges for healthcare systems worldwide. The overwhelming number of patients infected with the virus placed an enormous burden on healthcare providers, who struggled to cope with the sheer volume of cases. Furthermore, the lack of effective treatments or vaccines means that quarantining has become a necessary measure to slow the spread of the virus. However, quarantining places a significant burden on healthcare providers, who often lack the resources to monitor patients with mild symptoms or asymptomatic patients. In this study, we propose an Internet of Things (IoT)-based wearable health monitoring system that can remotely monitor the exact locations and physiological parameters of quarantined individuals in real time. The system utilizes a combination of highly miniaturized optoelectronic and electronic technologies, an anti-epidemic watch, a mini-computer, and a monitor terminal to provide real-time updates on physiological parameters. Body temperature, peripheral oxygen saturation (SpO2), and heart rate are recorded as the most important measurements for critical care. If these three physiological parameters are aberrant, then it could represent a life-endangering situation and/or a short period over which irreversible damage may occur. Therefore, these parameters are automatically uploaded to a cloud database for remote monitoring by healthcare providers. The monitor terminal can display real-time health data for multiple patients and provide early warning functions for medical staff. The system significantly reduces the burden on healthcare providers, as it eliminates the need for manual monitoring of patients in quarantine. Moreover, it can help healthcare providers manage the COVID-19 pandemic more effectively by identifying patients who require medical attention in real time. We have validated the system and demonstrated that it is well suited to practical application, making it a promising solution for managing future pandemics. In summary, our IoT-based wearable health monitoring system has the potential to revolutionize healthcare by providing a cost-effective, remote monitoring solution for patients in quarantine. By allowing healthcare providers to monitor patients remotely in real time, the burden on medical resources is reduced, and more efficient use of limited resources is achieved. Furthermore, the system can be easily scaled to manage future pandemics, making it an ideal solution for managing the health challenges of the future.

Wearable Optical Fiber Sensors for Biomechanical Measurement in Medical Rehabilitation: A Review

With the increasing demand for rehabilitation of the elderly population and patients with limb injuries, it is imperative to develop new wearable health monitoring system and assistive rehabilitation equipment. Optical fiber sensing has the advantages of light-weight, anti-electromagnetic interference, higher strain and elastic limit, safety and dependableness. It has been significantly utilized in engineering prospecting, building structure monitoring, and medical and health fields. At present, the application of optical fiber sensing in medical rehabilitation has been developed rapidly, however, the discussion and summary of its key theories and technologies are insufficient. This review details different types of optical fiber sensing mechanisms and devices, as well as the measurement of physical parameters using optical fiber sensors and application examples in the field of medical rehabilitation. This review systematically analyzes the advance of the sensitivity, flexibility, accuracy, and wearability of the optical fiber sensing in the monitoring of human body sign information. This review also discusses the challenges of making a new generation of optical fiber sensors that fit human joints, muscles, and rehabilitation equipment. Finally, this review provides a research direction for the realization of flexible, comfortable, safe, stable monitoring of human biomechanical parameters and real-time precise control of rehabilitation equipment in the future.

Multifunctional Wearable System for Mapping Body Temperature and Analyzing Sweat.

Integrated wearable bioelectronic health monitoring systems have revealed new possibilities for collecting personalized physiological information. Wearable sweat sensors have the potential to noninvasively measure valuable biomarkers. Mapping sweat and skin-temperature throughout the body can provide detailed information on the human body. However, existing wearable systems cannot evaluate such data. Here, we report a multifunctional wearable platform that can wirelessly measure local sweat loss, sweat chloride concentration, and skin temperature. The approach combines a reusable electronics module to monitor skin temperature and a microfluidic module for monitoring sweat loss and sweat chloride concentration. The miniaturized electronic system takes temperature measurements from the skin and wirelessly transmits the obtained data to a user device using Bluetooth technology. In contrast, the microfluidic system provides accurate colorimetric analysis of the chloride concentration and sweat loss. Thus, this integrated wearable system has great application potential in individualized health management systems for sports researchers and competitors and can also be applied in clinical settings.