This paper presents an operator-friendly and cost-efficient approach to characterize the dielectric permittivity of liquids flowing in narrow tubes, such as drainage tubes used as part of the wound healing process in hospitals. The approach is based on an oscillator such that the characterization can be achieved with minimal operator (e.g., nurse) training. The oscillator's frequency is set by a 3D-printed cavity resonator as to offer flexibility for the tube line to pass through. The oscillator design had to be tailored to ensure the oscillation condition to be met over a wide range of varying liquid compositions passing through the 3D-printed cavity resonator. The design and results of a proof-of-concept implementation are presented and discussed.

中文翻译：

---

采用 3D 打印腔谐振器的液体介电常数测量的有效方法

本文提出了一种操作员友好且具有成本效益的方法来表征在窄管中流动的液体的介电常数，例如用作医院伤口愈合过程的一部分的引流管。该方法基于振荡器，从而可以通过最少的操作员（例如护士）培训来实现表征。振荡器的频率由 3D 打印的腔体谐振器设置，以便为管线通过提供灵活性。振荡器设计必须进行调整，以确保在通过 3D 打印腔谐振器的各种不同液体成分上都能满足振荡条件。提出并讨论了概念验证实施的设计和结果。