Wearable devices are electronic devices that can be worn for a variety of reasons, such as tracking daily activities or managing a schedule, but more importantly, they empower wearers and caregivers by providing access to important health data, which can be used to diagnose and monitor health. condition.
Image credit: UC San Diego
Recently, a research team at the University of San Diego has been working on a photoacoustic sensor that could give clinicians access to important data that would help them diagnose tumors, organ malfunctions and other health problems. Built into a wearable skin patch, the sensor monitors biomolecules such as hemoglobin in deep tissue.
Published in the magazine Nature communicationreveals how its new innovative wearable photoacoustic sensor could provide access to an unprecedented wealth of data that could revolutionize clinical diagnosis in the near future.
With access to vital information and the ability to diagnose a wide range of potentially life-threatening health conditions in a rapid and uncomplicated manner, researchers will be able to gain a better understanding of these pathophysiological conditions and thus facilitate timely medical interventions to ensure better outcomes in the future.
Monitoring of endogenous biomolecules
While the team believes its system can be modified and recalibrated to detect other biomolecules such as cytochrome, glucose, lipids, melanin, nucleic acid,., and proteins, for this study they monitored hemoglobin.
The amount and location of hemoglobin in the body provide crucial information about blood flow or accumulation in specific locations. Our device has great potential for accurate monitoring of risk groups, enabling timely intervention at urgent moments.
Sheng Xu, professor of nanoengineering, UC San Diego
Those with low blood perfusion are at greater risk of vascular disease and more likely to have heart attacks. In addition, abnormalities in hemoglobin levels can indicate other problems, such as the presence of a tumor. Therefore, monitoring and tracking endogenous biomolecules in the body could improve the data clinicians work with and overcome some of the challenges that hold back existing technologies.
For example, X-ray computed tomography monitoring and magnetic resonance imaging (MRI) are limited by the fact that they are usually large, cumbersome devices that are limited in terms of access and availability. In addition, these technologies usually only provide immediate insight into the state of biomolecules, making them less efficient for long-term tracking.
Ongoing monitoring is critical for timely interventions to prevent life-threatening conditions from rapidly exacerbating.
Xiangjun Chen, Nanoengineering Ph.D. student, UC San Diego
The new, innovative wearable skin patch developed by Xu and the team has a relatively low form factor and is extremely flexible, enabling active, non-invasive monitoring over an extended period of time.
Monitoring on the go
With the ability to map hemoglobin in 3D, the device also offers excellent submillimeter spatial resolution and can penetrate the skin for monitoring hemoglobin in deep tissues, whereas other existing wearables can only measure at the surface level of the skin.
The patch consists of a network of piezoelectric transducers and laser diodes held together in a soft silicon polymer matrix. The laser diodes emit pulsed lasers, which penetrate the skin tissue, and biomolecules absorb the optical energy and reflect acoustic waves, which are then detected by the photoacoustic sensor.
Piezoelectric transducers receive the acoustic waves, which are processed in an electrical system to reconstruct the spatial mapping of the wave-emitting biomolecules.
Xiaoxiang Gao, postdoctoral researcher, UC San Diego
The new design is also safer than X-ray techniques and more comfortable than undergoing an MRI scan. However, the team wants to rework the design, miniaturizing bulky ultrasound probes and eliminating the need to use laser machines, both of which impact the device’s portability and ease of use.
Future efforts will focus on fabricating a fully integrated wearable to enable long-term measurements on the go. The hope is that the wearable photoacoustic health sensor will enable clinicians to make early and effective diagnoses of life-threatening conditions.
References and further reading
Dameron, E. (2022) Portable skin patch monitors hemoglobin in deep tissues, Today. Available at: https://today.ucsd.edu/story/wearable-skin-patch-monitors-hemoglobin-in-deep-tissues
Gao, X. et al. (2022) “A photoacoustic patch for three-dimensional imaging of hemoglobin and core temperature”, Nature communication, 13(1). Available at: https://www.nature.com/articles/s41467-022-35455-3
