Chronic wounds are a major health concern and they affect the lives of more than 25 million people in the United States. They are susceptible to infection and are the leading cause of nontraumatic limb amputations worldwide. The wound environment is dynamic, but their healing rate can be enhanced by administration of therapies at the right time. This approach requires real‐time monitoring of the wound environment with on‐demand drug delivery in a closed‐loop manner.
A team of scientists at the National University of Singapore has developed a dressing that continuously shows how the wound is faring – without needing a power source. The smart bandage is called PETAL (Paper-like Battery-free In situ AI-enabled Multiplexed) sensor patch. Along with being a bit of a forced acronym, the bandage's name also refers to the fact that it looks (sort of) like a pinwheel flower.
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"We designed the paper-like PETAL sensor patch to be thin, flexible, and biocompatible, allowing it to be easily and safely integrated with wound dressing for the detection of biomarkers," said the principal scientist, Dr. Su Xiaodi. "We can thus potentially use this convenient sensor patch for prompt, low-cost wound care management at hospitals or even in non-specialist healthcare settings such as homes."
The co includes three layers: a lower layer made of medical tape that sticks to the skin surrounding the injury, a middle layer called the "fluidic panel" composed of wax paper with microfluidic channels arranged in the shape of a five-petalled flower, and an upper layer made of breathable transparent silicone.
The fluid from the wound is passively sucked via a hole in the fluidic panel when the PETAL is placed in it, and it is then distributed into the five channels that make up the petals of the flower.
One of five "wound indicators" — temperature, pH, uric acid levels, moisture, and concentrations of a metabolic waste product known as trimethylamine — causes a chemical present in a reservoir at the end of each channel to change color once the fluid reaches it.
It is feasible to evaluate the present status of the wound without removing the dressing by taking a smartphone snapshot of the PETAL and then using an AI-based app to analyze the colors of the reservoirs in that photo. The technique was tested on rats and found to be 97% accurate at telling the difference between chronic and burn wounds that were healing and those that weren't.
