In a recent review published in Communications Materials, researchers reviewed recent improvements in neonatal wearable systems, focusing on skin-interface wearables for physiological monitoring across many sectors.
Research: Skin-interfaced wearable biosensor for smart health monitoring of infants and newborns. Image credit: Gorodenkoff/Shutterstock.com
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Health assessment of infant patients in critical care can be particularly challenging for patients and their caregivers, as the testing environment requires several catheters, probes, and electrodes that restrict patient movement.
Health assessments typically require expensive and cumbersome equipment to monitor physiological parameters such as respiratory rate, heart rate, blood oxygen saturation, temperature, ion concentrations, and blood pressure.
However, over the past few decades, scientific advances have eclipsed current procedures with wearable, non-invasive, and soft technologies.
About reviews
In this review, researchers investigated the material basis of wearable devices, focusing on concepts and technological improvements in key physiological monitoring fields such as biopotential, optical, temperature, electrochemical, and multi-signal sensing. .
Development of materials for wearable sensors
Epidermal electronic systems (EES) are soft, flexible electronic devices created using microelectromechanical systems (MEMS) technology. These devices have the same material as the epidermis, giving them a high degree of flexibility.
Thin film materials such as polyimide or thin metal evaporation can be used as conductive layers, resulting in ultrathin and flexible devices with subnanometer bending stiffness and an effective modulus of 140 kPa.
EES can be easily applied to the skin using a thin adhesive transfer film or a moist bandage. The third stage serpentine combines dynamic movement with the skin, high signal quality and continuous contact with the skin surface.
Elastomers are cheaper than silicon wafer technology and are ideal substrates for integrating soft electronics into EES. Elastomeric encapsulation can be used for hybrid electronic systems because it combines flexible EES sensor devices, rigid active and passive electronics, wireless communications, and information processing to provide an all-in-one instrument that facilitates real-time monitoring. .
Textiles are often used to incorporate biosignal sensing devices due to their convenience and familiarity. Techniques include weaving conductive fibers, stitching into nylon or polyurethane coated with gold or silver, and printing electrical ink onto the fibers.
These components can be easily attached to clothing such as onesies, straps, and coats. Textile electrodes integrated into clothing minimize the requirements for conductive gel and tape, but signal quality is reduced.
Capacitive and resistive strain responses from conductive fibers allow assessment of physiological parameters such as respiratory rate and motility.
Data can be transferred via cable connections or cumbersome radio transmitters, but antennas can also be woven into clothing and combined with RFID tags to transfer data wirelessly without batteries.
Wearable sensors used to monitor physiological conditions
The human body generates action potentials through a chemical process monitored by electrodes on the skin. These biopotential signals include electrocardiograms (ECGs) that measure heart activity, electromyograms (EMGs) that activate muscles, electroencephalograms (EEGs) that measure brain activity, and EEGs that track eye movements. important to monitor.
Researchers have created an all-in-one EES system that mimics vital sign monitoring in a neonatal intensive care unit (NICU). This includes wireless inductive power transmission and data exchange to a host reader platform located under the patient's mattress. This technique is mechanically sensitive and requires a conductive gel.
EEG is a diagnostic technique that uses electrodes implanted in the head to measure the electrical activity of the brain. Common modalities include single-channel amplitude-integrated EEG (aEEG) and multichannel continuous EEG (cEEG), with cEEG being the gold standard.
There are several studies that physically redesign EEG electrode systems. However, most advances involve the development of textile caps or bands to enhance electrode placement while using typical wet electrodes.
Optical sensing for medical applications uses spectrophotometric principles to examine physiological processes transcutaneously and non-invasively.
Researchers have developed a forehead reflex PPG for preterm infants, a flexible PPG sensor for the feet, and a wireless system to monitor cerebral hemodynamics in infants.
Neonatal non-invasive thin-film biomarker sensing focused on sweat, saliva, and urine can replace standard blood sampling in the detection of chemical or protein biomarkers for health pre-diagnosis, diagnosis, and prognosis. You can use it.
Electrochemical sensing detects charge transfer on a sensing electrode, allowing wearables to record changes in current, conductivity, and voltage/potential.
Researchers created a multi-signal system that uses binodal ECG and PPG measurement devices to determine pulse arrival time, calculate pulse transit time, and measure cardiac seismograms.
conclusion
Based on review results, flexible electronics and wearable health monitoring technologies have improved patient outcomes by detecting physiological indicators rather than invasive treatments.
Advanced signal processing enables medical applications such as blood pressure and body temperature imaging. The miniaturization of electronic devices has led to medical advances, especially in neonatal applications where small footprint, delicate handling, and ease of use are important.
Wearable stethoscopes for asthma monitoring and wearable dry electroencephalography for seizure monitoring are recent technologies that have simplified treatment options in the NICU. Automated monitoring systems are particularly beneficial for sick school-age children and may increase their independence and self-sufficiency.
