Non-invasive alcohol and glucose detection using microwave resonators

Road safety is one of the priorities for every government in Europe and including in the UK. One of the major concerns for road safety is the consumption of alcohol by drivers which seriously increases the risk of an accident. According to the department of transport in 2007, there were over 17,000 drink-drive casualties including 530 fatalities in England alone. For this reason, the police force needs a fast and easy way to assess the alcohol level of drivers. We propose a new method of detection, using microwaves, which would detect the alcohol-blood ratio from the finger/wrist of the driver. We also study the possibility of blood sugar detection for diabetes using microwave resonators. The system is based on microwave resonators using very low power sources (lmW). This PhD project explores the limits and feasibility of a rectangular cavity resonator and a microstrip suspended ring resonator for use with water/ethanol samples and water/glucose samples. Samples of water/ethanol are tested in three parts for each sensor, 0% (water) to 100% (ethanol) in 5% increments, 1% to 5% in 1% increments and samples less than to 1% in 0.2% increments. Samples of water/glucose are tested from Omol of glucose to 1mol per litre of water in O.lmol/1 increments. Both systems are studied, designed, simulated and tested for the full ranges of both mixtures. The data acquisition software has been written in C# in order to allow ease of data extraction and manipulation during the tests. Using variables such as the Qfactor, the resonant frequency and the reflection coefficient, the resonators can detect permittivity changes in the samples. The rectangular cavity is able to detect a lower limit of 1% of ethanol, and a tenth of a mole for water/glucose mixtures. The suspended ring resonator can detect down to 1% of ethanol using the Q-factor, the resonant frequency and the magnitude and down to 0.2% using the transmission magnitude at a fixed frequency. This method can also detect a lower limit of O.lmol/l for glucose/water mixtures

Estudio y optimización de sensores de microondas para la caracterización y monitorización de materiales en procesos industriales

En esta tesis se realiza el análisis y la optimización del diseño de sensores de microondas, basados tanto en guías de onda coaxiales como en circuitos planares, para poder llevar a cabo la caracterización dieléctrica de materiales, así como la monitorización de los mismos en procesos industriales. Se describen novedosos métodos de diseño para conseguir que los sensores proporcionen la máxima sensibilidad a los cambios de las propiedades dieléctricas de los materiales; y se aplican nuevos modelos de análisis de los sensores de microondas, más completos que los existentes hasta el momento. Todo ello ha permitido desarrollar con éxito diversas aplicaciones tanto en el ámbito industrial como en el de laboratorio.García Baños, B. (2008). Estudio y optimización de sensores de microondas para la caracterización y monitorización de materiales en procesos industriales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/10628Palanci

Microwave resonant sensors

Microwave resonant sensors use the spectral characterisation of a resonator to make high sensitivity measurements of material electromagnetic properties at GHz frequencies. They have been applied to a wide range of industrial and scientific measurements, and used to study a diversity of physical phenomena. Recently, a number of challenging dynamic applications have been developed that require very high speed and high performance, such as kinetic inductance detectors and scanning microwave microscopes. Others, such as sensors for miniaturised fluidic systems and non-invasive blood glucose sensors, also require low system cost and small footprint. This thesis investigates new and improved techniques for implementing microwave resonant sensor systems, aiming to enhance their suitability for such demanding tasks. This was achieved through several original contributions: new insights into coupling, dynamics, and statistical properties of sensors; a hardware implementation of a realtime multitone readout system; and the development of efficient signal processing algorithms for the extraction of sensor measurements from resonator response data. The performance of this improved sensor system was verified through a number of novel measurements, achieving a higher sampling rate than the best available technology yet with equivalent accuracy and precision. At the same time, these experiments revealed unforeseen applications in liquid metrology and precision microwave heating of miniature flow systems.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Microwave resonant sensors

Microwave resonant sensors use the spectral characterisation of a resonator to make high sensitivity measurements of material electromagnetic properties at GHz frequencies. They have been applied to a wide range of industrial and scientific measurements, and used to study a diversity of physical phenomena. Recently, a number of challenging dynamic applications have been developed that require very high speed and high performance, such as kinetic inductance detectors and scanning microwave microscopes. Others, such as sensors for miniaturised fluidic systems and non-invasive blood glucose sensors, also require low system cost and small footprint. This thesis investigates new and improved techniques for implementing microwave resonant sensor systems, aiming to enhance their suitability for such demanding tasks. This was achieved through several original contributions: new insights into coupling, dynamics, and statistical properties of sensors; a hardware implementation of a realtime multitone readout system; and the development of efficient signal processing algorithms for the extraction of sensor measurements from resonator response data. The performance of this improved sensor system was verified through a number of novel measurements, achieving a higher sampling rate than the best available technology yet with equivalent accuracy and precision. At the same time, these experiments revealed unforeseen applications in liquid metrology and precision microwave heating of miniature flow systems