Bio-integrated wearable systems can measure a broad range of biophysical, biochemical, and environmental signals to provide critical insights into overall health status and to quantify human performance. Recent advances in material science, chemical analysis techniques, device designs, and assembly methods form the foundations for a uniquely differentiated type of wearable technology, characterized by noninvasive, intimate integration with the soft, curved, time-dynamic surfaces of the body. This review summarizes the latest advances in this emerging field of “bio-integrated” technologies in a comprehensive manner that connects fundamental developments in chemistry, material science, and engineering with sensing technologies that have the potential for widespread deployment and societal benefit in human health care. An introduction to the chemistries and materials for the active components of these systems contextualizes essential design considerations for sensors and associated platforms that appear in f...

Bio-Integrated Wearable Systems: A Comprehensive Review

As Internet of Things (IoT) devices and other remote patient monitoring systems increase in popularity, security concerns about the transfer and logging of data transactions arise. In order to handle the protected health information (PHI) generated by these devices, we propose utilizing blockchain-based smart contracts to facilitate secure analysis and management of medical sensors. Using a private blockchain based on the Ethereum protocol, we created a system where the sensors communicate with a smart device that calls smart contracts and writes records of all events on the blockchain. This smart contract system would support real-time patient monitoring and medical interventions by sending notifications to patients and medical professionals, while also maintaining a secure record of who has initiated these activities. This would resolve many security vulnerabilities associated with remote patient monitoring and automate the delivery of notifications to all involved parties in a HIPAA compliant manner.

Healthcare Blockchain System Using Smart Contracts for Secure Automated Remote Patient Monitoring

Flexible electronics, as an emerging and exciting research field, have brought great interest to the issue of how to make flexible electronic materials that offer both durability and high performance at strained states. With the advent of on-body wearable and implantable electronics, as well as increasing demands for human-friendly intelligent soft robots, enormous effort is being expended on highly flexible functional materials, especially stretchable electrodes, by both the academic and industrial communities. Among different deformation modes, stretchability is the most demanding and challenging. This review focuses on the latest advances in stretchable transparent electrodes based on a new design strategy known as kirigami (the art of paper cutting) and investigates the recent progress on novel applications, including skin-like electronics, implantable biodegradable devices, and bioinspired soft robotics. By comparing the optoelectrical and mechanical properties of different electrode materials, some of the most important outcomes with comments on their merits and demerits are raised. Key design considerations in terms of geometries, substrates, and adhesion are also discussed, offering insights into the universal strategies for engineering stretchable electrodes regardless of the material. It is suggested that highly stretchable and biocompatible electrodes will greatly boost the development of next-generation intelligent life-like electronics.

Flexible Electronics: Stretchable Electrodes and Their Future

Cardiovascular disease is the leading cause of death and has dramatically increased in recent years. Continuous cardiac monitoring is particularly important for early diagnosis and prevention, and flexible and stretchable electronic devices have emerged as effective tools for this purpose. Their thin, soft, and deformable features allow intimate and long-term integration with biotissues, which enables continuous, high-fidelity, and sometimes large-area cardiac monitoring on the skin and/or heart surface. In addition to monitoring, intimate contact is also crucial for high-precision therapies. Combined with tissue engineering, soft bioelectronics have also demonstrated the capability to repair damaged cardiac tissues. This review highlights the recent advances in wearable and implantable devices based on flexible and stretchable electronics for cardiovascular monitoring and therapy. First, wearable/implantable soft bioelectronics for cardiovascular monitoring (e.g., the electrocardiogram, blood pressure, and oxygen saturation level) are reviewed. Then, advances in cardiovascular therapy based on soft bioelectronics (e.g., mesh pacing, ablation, robotic sleeves, and electronic stents) are discussed. Finally, device-assisted tissue engineering therapy (e.g., functional electronic scaffolds and in vitro cardiac platforms) is discussed.

Wearable and Implantable Devices for Cardiovascular Healthcare: from Monitoring to Therapy Based on Flexible and Stretchable Electronics

Athletes are continually seeking new technologies and therapies to gain a competitive edge to maximize their health and performance. Athletes have gravitated toward the use of wearable sensors to monitor their training and recovery. Wearable technologies currently utilized by sports teams monitor both the internal and external workload of athletes. However, there remains an unmet medical need by the sports community to gain further insight into the internal workload of the athlete to tailor recovery protocols to each athlete. The ability to monitor biomarkers from saliva or sweat in a noninvasive and continuous manner remain the next technological gap for sports medical personnel to tailor hydration and recovery protocols per the athlete. The emergence of flexible and stretchable electronics coupled with the ability to quantify biochemical analytes and physiological parameters have enabled the detection of key markers indicative of performance and stress, as reviewed in this paper.

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Wearable sensors for monitoring the physiological and biochemical profile of the athlete

Contemporary cardiac and heart rate monitoring devices capture physiological signals using optical and electrode-based sensors. However, these devices generally lack the form factor and mechanical flexibility necessary for use in ambulatory and home environments. Here, we report an ultrathin (~1 mm average thickness) and highly flexible wearable cardiac sensor (WiSP) designed to be minimal in cost (disposable), light weight (1.2 g), water resistant, and capable of wireless energy harvesting. Theoretical analyses of system-level bending mechanics show the advantages of WiSP’s flexible electronics, soft encapsulation layers and bioadhesives, enabling intimate skin coupling. A clinical feasibility study conducted in atrial fibrillation patients demonstrates that the WiSP device effectively measures cardiac signals matching the Holter monitor, and is more comfortable. WiSP’s physical attributes and performance results demonstrate its utility for monitoring cardiac signals during daily activity, exertion and sleep, with implications for home-based care. A highly flexible, low-power wearable sensor that harvests energy and monitors cardiac signals has been developed by Lee et al. The team was led by Dr. Roozbeh Ghaffari and co-workers at MC10 Inc. and Northwestern University’s Center for Bio-Integrated Electronics at the Simpson & Querrey Institute, in collaboration with the Massachusetts General Hospital and Tsinghua University. The novel wearable sensors measure cardiac signals comparable in signal fidelity to those achievable with expensive monitoring systems used in hospitals. Wearable health-care solutions are fundamentally changing the way we monitor our well-being at all times of the day, no matter whether we are asleep at home or busy at work. The sensors reported here are lightweight, inexpensive to manufacture, robust to everyday use, and capable of wireless data transmission and energy harvesting to and from a smartphone. The approach proved successful for measuring episodic electrocardiograms (ECG) and continuous heart rate signals with significantly higher patient comfort scores compared to standard Holter monitors in an initial pilot study conducted at the Massachusetts General Hospital (MGH).

/pdf/highly-flexible-wearable-and-disposable-cardiac-biosensors-1fuyh2b4eo.pdf

Highly flexible, wearable, and disposable cardiac biosensors for remote and ambulatory monitoring.

The present invention describes breathable multilayered adhesive structures that can be used as adhesives to mount devices onto the skin. The breathable multilayered adhesive structures can comprise moisture-wicking layers adhered to the skin by a porous adhesion layer. The pores allow moisture released from the skin to be transferred away through the moisture-wicking layer. The adhesive structures permit the devices to be skin-mounted for an extended period of time (e.g., a few hours or days) without causing moisture-associated skin injuries such as erythema, maceration, and irritation or inflammation.

Moisture wicking adhesives for skin-mounted devices

The present invention describes multilayered adhesive structures that can be used as adhesives to mount wearable devices onto the skin. The multilayered adhesive structures can comprise a buffer layer sandwiched between two adhesive layers, a first adhesive layer adhering the multilayered adhesive structure to the wearable device and a second adhesive layer adhering the buffer layer to the skin. The buffer layer separates or isolates the wearable device from the skin. By mechanically buffering the wearable device from the skin, the multilayered adhesive structures permit the devices to be skin-mounted for an extended period of time (e.g., a few hours or days) without causing moisture-associated skin injuries such as erythema, maceration, and irritation or inflammation.

Buffered adhesive structures for wearable patches

A composition for application to a substrate to form a film or deposit for quantifying a fluid, or one or more analytes within a fluid, is disclosed. The composition includes a carrier configured as a transport medium for application of the composition to a substrate and at least one salt of chloranilic acid. The carrier can include at least one compound soluble within a bodily fluid and configured to at least partially solidify upon application of the composition on the substrate. The carrier can optionally include a liquid medium as a bulk transport medium for application of the composition. In some aspects, the liquid medium can be water, the at least one compound can be one or more water-soluble polymers, and the salt of chloranilic acid can be silver chloranilate. A color change in response to the film or deposit dissolving in the fluid and the at least one salt of chloranilic acid reacting with the one or more analytes allows for the quantification of the one or more analytes, and/or a quantification of the volume and/or flow rate of the fluid.

Hakan Mutlu

Papers

Highly flexible, wearable, and disposable cardiac biosensors for remote and ambulatory monitoring.

Moisture wicking adhesives for skin-mounted devices

Buffered adhesive structures for wearable patches

Materials and methods for the quantification of a fluid