Microwave Blood Sensing for Monitoring Treatment Efficiency in Hypertensive Patients with Chronic Neurological Disorders

The present work is a continuation of our multidisciplinary study on optimizing therapy in patients with chronic neurological conditions. Here we aim to monitor the efficiency of antihypertensive treatment via microwave blood sensing technique. The concept of microwave sensing is based on in vitro detecting drug-induced dielectric response $(\Delta\varepsilon^{*})$ of erythrocytes. This response is closely tied to a membrane adrenergic activity exhibiting individual peculiarities of the stress system, which varies significantly depending on a patient's health status and stage of the disease. That is why its evaluation during the course of treatment is of great importance for appropriate medication therapy (in particular, with prescribing antihypertensive drugs) as well as for the monitoring treatment efficiency. The study of these drug-induced effects in blood samples has been carried out using a complex of physical and biochemical methods. Microwave dielectric observations were performed as the repeated permittivity measurements of blood samples with a single-frequency waveguide-based reflectometry (39.5 GHz). To validate the results of the dielectric study we opted for a biochemical technique which allows evaluating the adrenergic effect of a pharmaceutical agent to erythrocytes. Both techniques have revealed well-correlated data which indicate the successful applicability of such an approach when considering the adrenergic status of a patient in antihypertensive treatment. Previously reported data supplemented by new findings are presented. The results would be helpful for the specialists dealing with microwave measurements of blood and the developers of clinically-oriented microwave systems.