Wound healing is a delicate tissue regeneration procedure that entails numerous changes in various physiological parameters.
FREMONT, CA: Wearable sensors and systems refer to devices that can detect minute amounts of biological or chemical analytes and convert chemical reactions or physical changes into usable signals (optical or electrical signals, for example) following predefined rules. Wearable sensors/systems for monitoring markers in or around the wound environment can provide real-time symptom information and hold promise for therapy studies, which also meets the World Union of Wound Healing Societies' requirement that "diagnostic tools be moved into the clinic or patient's home to ensure optimal care is provided for patients with wounds.” Researchers have developed various wearable sensors/systems based on optical (fluorescence, colorimetry, etc.) or electrical (impedance, potentiometry, amperometry, etc.) mechanisms integrated with conventional wound dressings to form innovative wound dressings. These smart wound dressings convert changes in these biomarkers into visual or electrical signals, allowing for real-time monitoring of wound healing.
pH Sensors and Monitoring Systems for Wounds
The pH of the wound milieu is a significant biochemical marker that plays a role in the wound healing process. The pH of normal skin and easing wounds is typically between 4 and 6.5 (i.e., acidic), optimal for promoting angiogenesis and epithelization, facilitating oxygen delivery, and sustaining resident commensal bacteria. However, infected wounds have an alkaline pH (greater than 6.5), which has been linked to bacteria. Thus, pH has been identified as a critical diagnostic parameter for determining the presence of infection. With growing interest in pH analysis within the wound environment, pH sensing platforms based on various optical or electrochemical techniques have been developed for in-situ and real-time monitoring and analysis of wound healing status.
Wearable Temperature Sensors and Wound Monitoring Systems
Temperature variation has been identified as a critical parameter associated with wound inflammation and infection, as abnormal temperature changes affect a series of chemical and enzymatic reactions involved in the wound healing process. On the one hand, local vascular expansion increased the temperature of the acute wound, thereby shipping more oxygen and nutrients to the injured place. The temperature of voluntarily healed wounds is more significant than 37.8 degrees Celsius but not significantly greater than the surrounding temperature. A rapid rise in temperature in the area of a chronic wound is indicative of infection. On the other hand, a decrease in local temperature indicates that the wound is likely to experience local ischemia, which can also be detrimental to wound rehabilitation. A temperature variation of 2.2 degrees Celsius is a warning sign of impending wound deterioration. As a result, temperature monitoring has enormous potential as an effective method of determining the status of wounds. Several sensors are used to measure temperature, including infrared sensors, thermistors, and resistance temperature sensors.