Response Time of a Thin-Film Resistance Temperature Detector Phantom Applications

The thin-film RTD array sensor quickly detects a sudden thermal change inside a tissue-mimicking material (TMM) to validate high-intensity focused ultrasound (HIFU) devices. The thermal response time of a thin-film resistance temperature detector (RTD) array sensor was measured for a high-intensity focused ultrasound (HIFU) phantom. As the temperature inside materials change rapidly within several seconds, it is important to have a temperature sensor with a fast response time to evaluate their performance. However, previous methods for measuring thermal response time were not suitable for thin-film sensors, and there were no quantitative data available. In this study, we used a liquid drop method to measure the thermal time constant of the thin-film RTD, which was found to be 1.0 ± 0.2 ms. This indicates that the thin-film RTD array sensor has a sufficiently fast response time to detect sudden temperature changes inside the tissue-mimicking material (TMM) for validating HIFU devices.