Portable, Low-Field NMR Relaxometry for Medical and Industrial Applications
Abstract: Recent technological advancements have now made portable nuclear magnetic resonance (NMR) spectroscopy economically and practically feasible. The ease with which it can be customized to address specific problems makes portable NMR an extremely desirable analytical technique. Here, two major projects are developed. They have a unified focus of improving portable, low field NMR from the standpoints of data processing and theory, as well as broadening its immediate applications in medicine and industry. First, the matrix pencil method (MPM) is explored for high resolution data processing in low field NMR. Improving the efficiency of data processing will expand the potential applications of portable NMR and enhance the quality of information that is gained from experiments. The MPM is developed as an alternative technique to the inverse Laplace transform (ILT), due to its high resolution and minimal computational requirements. The success of the MPM in other areas of signal processing makes its application to low field NMR promising. Next, it is shown that portable NMR relaxometry can be used to rapidly estimate the water content of blood plasma (PWC) in clinical settings. This is achieved by correlating the T1 and T2 decay constants to the percentage of water in plasma samples. The societal impact of this work is quite significant. A large percentage of medical decisions are based on laboratory tests, many of which are blood chemistry assays. However, the accuracy of blood tests can depend on PWC, which is not typically measured in clinical laboratories. Variance in PWC between patients can influence many test results, with blood electrolyte and metabolite measurements being perhaps the most notable. A rapid, NMR-based test to measure PWC can provide clinicians with a means to improve the accuracy of blood chemistry assays and diagnostic tests, which will improve patient care.