Magnetohydrodynamic Voltage Recorder for Comparing Peripheral Blood Flow

• Published in: Annals of biomedical engineering Vol. 45; no. 10; pp. 2298 - 2308
• Main Authors: Wu, Kevin J., Gregory, T. Stan, Lastinger, Michael C., Murrow, Jonathan R., Tse, Zion Tsz Ho
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.10.2017; Springer Nature B.V
• Subjects: Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Blood circulation; Blood flow; Blood Flow Velocity; Cardiovascular diseases; Classical Mechanics; Echocardiography; EKG; Electrocardiography; Electrocardiography - instrumentation; Electrocardiography - methods; Fluid dynamics; Fluid flow; Heart diseases; Humans; Magnetic fields; Magnetic resonance imaging; Magnetohydrodynamics; Magnetometry - instrumentation; Magnetometry - methods; Measurement methods; Monitoring; Neodymium; Peripheral blood; Portable equipment; Reproducibility; Smartphone; Smartphones; Stroke volume; Electrocardiography; ECG; MHD effect; Smartphone; Blood flow
• ISSN: 0090-6964; 1573-9686; 1573-9686
• DOI: 10.1007/s10439-017-1878-5

Blood flow is a clinical metric for monitoring of cardiovascular diseases but current measurements methods are costly or uncomfortable for patients. It was shown that the interaction of the magnetic field ( B 0 ) during MRI and blood flow in the body, through the magnetohydrodynamic (MHD) effect, produce voltages ( V MHD ) observable through intra-MRI electrocardiography (ECG), which are correlated with regional blood flow. This study shows the reproducibility of V MHD outside the MRI and its application in a portable flow monitoring device. To recreate this interaction outside the MRI, a static neodymium magnet (0.4T) was placed in between two electrodes to induce the V MHD in a single lead ECG measurement. V MHD was extracted, and integrated over to obtain a stroke volume metric. A smartphone-enabled device utilizing this interaction was developed in order to create a more accessible method of obtaining blood flow measurements. The portable device displayed a <6% error compared to a commercial recorder, and was able to successfully record V MHD using the 0.4T magnet. Exercise stress testing showed a V MHD increase of 23% in healthy subjects, with an 81% increase in the athlete. The study demonstrates a new device utilizing MHD interactions with body circulation to obtain blood flow metrics.