A Highly Integrated Biomedical Pressure-Temperature Sensor

The internal pressure of human organs and tissues is a crucial vital sign of humans. Monitoring pressure within the human body requires sensors that meet exacting standards for precision, volume, and biocompatibility. This article proposed a highly integrated biomedical pressure-temperature sensor, leveraging the Fabry-Perot (FP) cavity and fiber Bragg grating (FBG) sensing techniques. The FP cavity was fabricated and length controlled by chemical etching method using multimode optical fiber (MMF). Part of a miniature glass bubble was welded onto the FP cavity, serving as both a diaphragm and a reflector. The entire FP cavity structure was seamlessly integrated with a FBG through electric-arc welding, without extra dissimilar materials. The designed sensor boasts a compact structure, simple manufacturing process, and cost-effectiveness. The experimental results demonstrate its pressure sensitivity of 216.6 pm/kPa within a range of −30 to 50 kPa, and temperature sensitivity of 10.3 pm/°C from 20 °C to 55 °C. The corresponding detection accuracy for pressure and temperature is 0.1 kPa and 0.1 °C, respectively. The designed sensor has the potential to be applied to the monitoring of human pressure parameters such as intracranial pressure, intravascular pressure, endotracheal pressure, and so on.