Solving Inverse Problem in Magnetocardiography by Pattern Search Method

Abstract

In this paper, a novel way of choosing the initial estimates for solving magnetocardiographic inverse problems using the pattern search method is reported. As opposed to the conventional choice of pseudo random numbers, the co-ordinates of the maximum spatial gradient of magnetic fields across sensor locations were used as initial estimates for pattern search method with the help of current density maps. The proposed method has been extensively validated by computer simulation and test coil localization before applying to real magnetocardiogram of a few healthy subjects and those with a known conduction anomaly and ischemic heart disease.

KEYWORDS:

• Inverse problem
• Magnetic field maps
• Magnetocardiography
• Pattern search method
• Pseudo current density maps
• SQUID

Acknowledgements

The authors are thankful to Mr. R. Baskaran, Dr. N. V. Chandrasekar, Dr. G. Amarendra and Dr. Shaju K. Albert for their support and encouragement during the execution of this work. The authors also thank Mr. Pathan Fayaz Khan and Mr. C. Kesavaraja for their computational support and assistance during MCG measurement.

Additional information

Notes on contributors

Pragyna Parimita Swain

Pragyna Parimita Swain received her MSc degree in physical sciences from Utkal University, Bhubaneswar, Odisha. She is pursuing PhD from the SQUIDs and Applications Section, Materials Science Group at IGCAR, Kalpakkam affiliated to HBNI, Mumbai since 2015. Her research interest includes measurement of magnetocardiogram, biomedical signal processing and analysis.

S. Sengottuvel

S Sengottuvel received an ME degree in medical electronics from Anna University, Chennai. He joined Materials Science Group, IGCAR in 2010 as Dr K S Krishnan Research Fellow and subsequently as a scientific officer from 2011. His research interest includes measurement and analysis of weak biomagnetic fields with particular emphasis to cardiac signals.Email: [email protected]

Rajesh Patel

Rajesh Patel received his B.E in electronics and communication systems from RGPV, Bhopal and MTech in engineering physics from HBNI, Mumbai. He joined the Materials Science Group, IGCAR in 2008 as a scientific officer. His research interest includes acquisition and analysis of electroencephalogram and magne-toencephalogram signals.Email: [email protected]

Awadhesh Mani

Awadhesh Mani joined as a scientific officer at Materials Science Group, IGCAR in 1992. He received his doctoral degree in physical sciences from Madras University in 2004. His area of specialization includes cryogenics, low temperature-high pressure physics.Email: [email protected]

Raja J. Selvaraj

Raja J Selvaraj received MBBS degree from Kilpauk Medical College, Chennai and MD (Pediatrics) from Grant Medical College, Mumbai and DNB in cardiology. He has received a fellowship in cardiac electrophysiology from Torronto General Hospital, Canada. He has joined the JIPMER Hospital, Pondicherry as a practicing cardiologist in 2008 and presently is the head of the Department of Cardiology. His research specialization is on cardiac electrophysiology.Email: [email protected]

Santhosh Satheesh

Santhosh Satheesh has received MBBS degree from JIPMER, Pondicherry. He has received MD and DM in cardiology from JIPMER and has joined there as a practicing cardiologist in 2007. His research interest includes cardiology and interventional cardiology.Email: [email protected]