Researchers at the University of California San Diego (UCSD) have developed an electronic patch that can monitor biomolecules within deep tissues. It’s hoped that this patch will allow medical workers unprecedented access to crucial information that would aid in detecting life-threatening conditions, such as malignant tumors, organ dysfunction, and cerebral or gut hemorrhages.
“Continuous monitoring is critical for timely interventions to prevent life-threatening conditions from worsening quickly,” said Xiangjun Chen, study co-author. “Wearable devices based on electrochemistry for biomolecule detection, not limited to hemoglobin, are good candidates for long-term wearable monitoring applications. However, the existing technologies only achieve the ability of skin-surface detection.”
Technologies currently in use – such as MRI and X-ray-computed tomography – rely on bulky equipment and generally only provide information on the immediate status of the molecule. This makes them unsuitable for long-term biomolecule monitoring.
The patch from UCSD is designed to offer a noninvasive long-term monitoring option. For example, it can perform three-dimensional mapping of hemoglobin with a submillimeter spatial resolution in deep tissues, down to centimeters below the skin, compared to other devices that only detect biomolecules on the surface.
“The amount and location of hemoglobin in the body provide critical information about blood perfusion or accumulation in specific locations. Our device shows great potential in close monitoring of high-risk groups, enabling timely interventions at urgent moments,” said Sheng Xu, corresponding author of the study.
The wearable patch is flexible and comfortably attaches to the skin. It features arrays of laser diodes and piezoelectric transducers in a soft silicone polymer matrix, which send pulsed lasers into the tissues below. Biomolecules in the tissue absorb the optical energy and radiate acoustic waves into surrounding media.
“Piezoelectric transducers receive the acoustic waves, which are processed in an electrical system to reconstruct the spatial mapping of the wave-emitting biomolecules,” said Xiaoxiang Gao, co-author of the study.
The team plans to further develop the device by shrinking the backend controlling system to a portable-sized device for laser diode driving and data acquisition, with the goal of expanding its flexibility and potential clinical utility.