Atomic magnetometer points to better picture of heart conductivity

March 31, 2020

WASHINGTON, March 31, 2020 -- Mapping the electrical conductivity of the human heart would be a valuable tool in the diagnosis and management of diseases, such as atrial fibrillation. But doing so would require invasive procedures, none of which are capable of directly mapping dielectric properties.

Significant advances have been made recently that leverage atomic magnetometers, which are quantum devices, to provide a direct picture of electric conductivity of biological tissues. In this week's Applied Physics Letters, from AIP Publishing, new work in quantum sensors points to ways such technology could be used to examine the heart.

Researchers at University College London have modified approaches used in electromagnetic induction imaging to take a picture of the electrical conduction of models that resembles the human heart. Using a radio-frequency atomic magnetometer that relies on rubidium-87, the group achieved the level of performance required to image the dielectric properties of the supporting structures that drive cardiac function.

"For the first time, we have achieved, in unshielded environments, the sensitivity and stability for imaging low conductivity in small volumes that are comparable to the expected size of the anomalies seen in atrial fibrillation," said author Luca Marmugi. "Thus, we have demonstrated that noninvasive electromagnetic induction imaging of the heart is technically possible."

The device the UCL group has developed applies a small oscillating magnetic field that induces a signal in the heart and is detected by an ultrasensitive detector based on laser manipulation of atomic spins.

To map conductivity anomalies in the human heart, such a device would need to detect conductivities on the order of 0.7 to 0.9 siemens per meter. When tested on laboratory solutions of the same conduction features of the human heart, the group's device was able to yield a signal that small.

The results mark a fiftyfold improvement over previous attempts to capture such small specimens.

Marmugi said the group hopes to continue developing its magnetometer system for clinical use and looks to improve on machine learning techniques to better map heart conductivity data.

"Our work has demonstrated the feasibility of our idea proposed in 2016. Mission accomplished!" Marmugi said. "However, we know we cannot rest. In this sense, I hope it will trigger increased interested in this kind of applications, hopefully encouraging more and more groups to work in the same field and fostering new collaboration and ideas."
The article, "Sub-Sm-1 electromagnetic induction imaging with an unshielded atomic magnetometer," is authored by Cameron Deans, Luca Marmugi and Ferruccio Renzoni. The article will appear in Applied Physics Letters on March 31, 2020 (DOI: 10.1063/5.0002146). After that date, it can be accessed at


Applied Physics Letters features rapid reports on significant discoveries in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. See

American Institute of Physics

Related Atrial Fibrillation Articles from Brightsurf:

Atrial fibrillation less deadly than it used to be, but still cause for concern: BU study
A first-of-its-kind study by researchers from the Boston University School of Public Health (BUSPH) shows a decline in deaths related to atrial fibrillation (irregular heartbeat) over the last 45 years.

Postoperative atrial fibrillation does not impact on overall survival after esophagectomy
Volume 11, Issue 25 of Oncotarget reported that Administration of landiolol hydrochloride was found to be associated with reduced incidence of atrial fibrillation after esophagectomy for esophageal cancer in our previous randomized controlled trial.

People with atrial fibrillation live longer with exercise
More than 100,000 Norwegians have atrial fibrillation. They should be actively exercising for their health.

Atrial fibrillation among overweight people is not due to fat
In a recently published study, researchers from Aarhus University document that the risk of atrial fibrillation is not linked to the amount of body fat, but instead to large muscle mass, or more precisely, a high fat-free weight

Eating more protein could help ward off atrial fibrillation in women
Women who ate slightly more than the recommended daily amount of protein were significantly less likely to develop atrial fibrillation (AFib), a dangerous heart rhythm disorder that can lead to stroke and heart failure, when compared with those who consumed less protein, according to research being presented at the American College of Cardiology's Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC).

Zebrafish teach researchers more about atrial fibrillation
Genetic research in zebrafish at the University of Copenhagen has surprised the researchers behind the study.

Personalized medicine for atrial fibrillation
The study, published in Europace, uses signals from implantable devices -- pacemakers and defibrillators -- to analyze electrical signals in the heart during episodes of atrial fibrillation.

Prescribing anticoagulants in the ED for atrial fibrillation increases long-term use by 30%
Patients prescribed anticoagulants after a diagnosis of atrial fibrillation in the emergency department are more likely to continue long-term use of medications to treat the condition, according to research published in CMAJ (Canadian Medical Association Journal).

Anticoagulant benefits for atrial fibrillation decrease with age
The net clinical benefit of anticoagulants for atrial fibrillation (AF) -- one of the most important causes of irregular heartbeats and a leading cause of stroke -- decreases with age, as the risk of death from other factors diminishes their benefit in older patients, according to a study led by researchers at UC San Francisco.

Research improves understanding of mechanism of atrial fibrillation
Mouse model studies show that noncoding DNA regions linked to atrial fibrillation risk can display long-range regulatory functions directed at Pitx2 gene and in this way predispose to the condition.

Read More: Atrial Fibrillation News and Atrial Fibrillation Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to