Passive Self Resonant Skin Patch Sensor to Monitor Cardiac Intraventricular Stroke Volume Using Electromagnetic Properties of Blood

Abstract

This paper focuses on the development of a passive, lightweight skin patch sensor that can measure fluid volume changes in the heart in a non-invasive, point-of-care setting. The wearable sensor is an electromagnetic, self-resonant sensor configured into a specific pattern to formulate its three passive elements (resistance, capacitance, and inductance). In an animal model, a bladder was inserted into the left ventricle (LV) of a bovine heart, and fluid was injected using a syringe to simulate stoke volume (SV). In a human study, to assess the dynamic fluid volume changes of the heart in real time, the sensor frequency response was obtained from a participant in a 30° head-up tilt (HUT), 10° HUT, supine, and 10° head-down tilt positions over time. In the animal model, an 80-mL fluid volume change in the LV resulted in a downward frequency shift of 80.16 kHz. In the human study, there was a patterned frequency shift over time which correlated with ventricular volume changes in the heart during the cardiac cycle. Statistical analysis showed a linear correlation \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}${R} ^{2} = 0.98$ \end{document} and 0.87 between the frequency shifts and fluid volume changes in the LV of the bovine heart and human participant, respectively. In addition, the patch sensor detected heart rate in a continuous manner with a 0.179% relative error compared to electrocardiography. These results provide promising data regarding the ability of the patch sensor to be a potential technology for SV monitoring in a non-invasive, continuous, and non-clinical setting.

An amplitude-based characteristic parameter extraction algorithm for cerebral edema detection based on electromagnetic induction

“…Electromagnetic induction measurement has high application prospects in bedside and point-of-care monitoring. Recently, Alruwailli et al showed that resonant skin patch sensors can be used to detect changes in the cardiac intraventricular stroke volume, thereby providing a non-invasive monitoring index for stroke patients [ 57 ]. Mohammed et al proposed a wearable readout system to carry out hemodynamic detection by extracting the radio frequency attributes of resonant frequency shift and magnitude variation [ 58 , 59 ].…”

Blood Pressure Sensors: Materials, Fabrication Methods, Performance Evaluations and Future Perspectives

“…Skin patch sensors based on electromagnetic (EM) detection were built from a conductive trace of copper to measure intravascular stroke volume [124] and intracranial blood pressure [158]. Also, a magnetoelastic skin curvature sensor along with ECG electrodes was used to measure blood pressure in the carotid [159].…”

“…In the stroke volume method, mean arterial blood pressure is estimated through measuring changes in the volume of blood pumped from the left ventricle (i.e., cardiac output) and the resistance that must be overcome to push blood and create flow in arteries (i.e., systemic vascular resistance) or through estimating cardiac output from O 2 consumption levels [ 123 ]. The accuracy of the contact [ 124 , 125 ] and non-contact [ 126 , 127 , 128 ] sensing modalities of the blood flow method is controversial. Contact sensing has met the gold standard level of accuracy under certain conditions and failed to meet it under others, whereas non-contact sensing modalities show a significant reduction in diagnostic performance [ 127 , 128 ].…”

MAS: Standalone Microwave Resonator to Assess Muscle Quality

“…Also, the feasibility of using the fat channel for intra-body communication at microwave frequencies has been studied [ 25 ]. In vivo characterization using microwave sensors have been done in hip fracture healing [ 26 ], to monitor intracranial pressure [ 27 ], measure fluid volume changes in the heart [ 28 ] and measure limb hemodynamics [ 29 ]. Recently, non-invasive techniques to characterize the dielectric properties and analyze variations in biological tissues are being studied for their potential to determine muscle mass and quality [ 30 ].…”