New Insight on BP Estimation Utilizing a Miniaturized Microstrip Patch Antenna

Abstract

Noninvasive monitoring of blood pressure (BP) is crucial for diagnosis and management of hypertension. The current cuff-based, continuous BP measurement methods require uncomfortable arterial compression for every intermittent measurement. Thus, we suggest the development of a novel flexible, wearable and miniaturized microstrip antenna that can provide continuous and easy to use estimates of blood pressure. This wearable antenna is designed in High Frequency Simulation Software (HFSS) and dedicated for transmitting and receiving signals at 2.4 GHz. It is also compact of 35 x 35 mm2 with a epoxy substrate of dielectric constant 4.3. The patch presents a gain of 6 dB and resonance over the frequency band 2.3-2.6 GHz, which falls in the targeted industrial, scientific, and medical (ISM) band. In order to check the safety of using the antenna on human body, this paper presents a computer-based design of a human arm and applies the antenna on it. The specific absorption rate is 1.74 W/Kg, which is below the IEEE safety standard cut-off. The paper also presents a discussion on a newly proposed algorithm that relates the variation in electromagnetic waves along with variation in brachial artery specifications to estimate blood pressure parameters.