New PhD by Pritam Bose: Communication and Signal Transmission for In-body Cardiac Sensor Networks

19th November 2019 Pritam Bose from the Intervention Centre publicly defended his thesis “Communication and Signal Transmission for In-body Cardiac Sensor Networks". Title of the Trial Lecture was "The similarity and difference between in-body communication system design and cellular communication system design". First opponent: Professor Anja Skrivervik, École polytechnique fédérale de Lausanne, Second opponent: Associate Professor Bruno Clerckx, Imperial College London, Third member and chair of the evaluation committee: Professor Emeritus Knut Gjesdal, University of Oslo. Chair of the Defence Professor Emeritus Odd Geiran, University of Oslo. Principal Supervisor, Professor Ilangko Balasingham, University of Oslo. See the announcement from University of Oslo.

Abstract:

Conventional cardiac pacemakers provide effective treatment of patients with certain heart rhythm abnormalities but require intravascular leads associated with risk of complications and infections. Current leadless pacemakers – self-contained capsule-like pacemakers – diminish risks but offers only single-chamber stimulation adequate only for a fraction of patients in need of pacemakers since most patients require dual- or triple-chamber pacing.

The optimal solution would be a system of multiple leadless pacemaker capsules that collectively provide multi-chamber pacing. To realize such a system, challenges including communication, power consumption, miniaturization and safety must be overcome. The thesis has contributed towards development of a communication framework of a novel multi-node pacemaker system. A communication network consisting of devices within the heart, in subcutaneous tissues and outside the body were investigated.

The cardiac channel modelling was investigated through computational simulations in human voxel models followed by design of electronics and miniaturised antennas for experiments in liquid phantom solutions and living animals.

The results showed that the optimal frequency of operation, based on the size constraints of the capsules, is located within the industrial, scientific and medical (ISM) band of 2.4 to 2.5 GHz. Our analysis suggests that the upper part of the abdominal wall provides the ideal position for a subcutaneous implant which may be utilized as a hub for capsule synchronisation and data storage. It was also evident that peak communication performance between intracardiac capsules occurs during end-systole and that the optimal modulation scheme for the communication framework is Gaussian frequency shift-keying (GFSK).

Overall, this thesis has laid a foundation towards the development of a multi-node leadless pacemaker system which may improve the lives of millions of patients suffering from cardiac rhythm disorders.