Radio-Frequency Atomic Magnetometers for Medical Applications

The project aims to combine a novel approach to measurement (mapping of low-conductivity samples) with the implementation of a novel type of sensor which results in a Magnetic Induction Tomography system for medical applications. This relies on a recent (2014) breakthrough by the UCL team, the demonstration of electromagnetic imaging with atomic magnetometers, and the subsequent (2016) proposal for its application in the diagnosis of atrial fibrillation. So far, only passive magnetic field mapping of the heart with a non-invasive method has been possible, whereas other conductivity mapping techniques require surgery. The developed technique for magnetic heart imaging through magnetic induction tomography would provide an unique alternative to invasive mapping of arrhythmia. The proposed research includes the following activities: (a) The assembly of an rf-atomic magnetometer portable system, and the evaluation of its performance in unshielded environment. This is required to assess the suitability for the operation in a clinical environment.
(b) Demonstration of magnetic induction at 1 MHz, and determination of the sensitivity of the apparatus for this type of measurements. This will be done by inducing eddy currents in a sample object and detecting the resulting magnetic field. The aim is to be able to detect a disk of 1 mm diameter and 1 mm thickness, and with conductivity corresponding to biological samples. This will pave the way for the use of the magnetometer in imaging for medical applications which will be the object of the research beyond the feasibility study associated with the present proposal.
(c) Development of the detection system components that will allow integration with imaging system.

The proposed research precisely aims to demonstrate a new approach to imaging for medical applications, and to develop corresponding novel instrumentations. It has thus the potential to have impact on the economy in the short and in the long term.

Immediate Impact: The ultra-sensitive RF magnetometer which will be designed for this project finds application in different fields, as monitoring of e.m. field pollution, and thus may become a commercial product for low-level magnetic field measurements in the MHz range. The funding for this project is thus likely to catalyse the development of devices which may become commercial products.

Long-term Vision: The long-term goal is to perform imaging of the human heart with all-optical atomic magnetometers operating in magnetic induction tomography modality. The possibility to create real-time conductivity maps of the heart may revolutionise the diagnosis and clinical treatment of atrial fibrillation. This will lead to a new instrumentation for the imaging of the heart both at the diagnosis stage and in the surgery phase, of direct benefit to the economy.