Highly sensitive sensors have been successfully used to map the electrical activity of the developing heart in embryos, in a University of Sussex study published today. Researchers say that the study could lead to new insight into how heart rhythm abnormalities develop.

The team fine-tuned the patented Electric Potential Sensor (EPS) technology, developed at the University, to detect the electrical signals of zebrafish embryos from just three days after fertilization. The findings have been published in the journal Applied Physics Letters.

This is the first time that scientists have been able to see the full picture of electrical activity in the developing heart of such a small organism, given that current electrocardiography (ECG) methods only measure the heartbeat.

Zebrafish hearts are remarkably similar to those of humans, making them a good model organism for scientific research. These latest results “push the frontiers” of the EPS technology and could help scientists better understand how the heart develops – particularly during the early stages of life – and how defects originate. Although the technique has not yet been tested on human embryos, the study nevertheless provides a solid ‘proof of principle’ to underpin further research.

Professor Robert Prance, head of the Sensor Technology Research Centre at the University of Sussex, said: “The EPS is a sensor technology that measures changes in an electric field in a similar way to a ‘perfect voltmeter’, drawing no current into the sample, making it non-invasive and safe to use. The sensor has already been used to carry out human ECG heart scans – or their cranial equivalent, electroencephalographs – saving patients from uncomfortable electrodes. Zebrafish embryo hearts are 2,500 times smaller than the human heart, so we needed to enhance the EPS design to make possible the detection of such cardiac activity. This could provide the biomedical research community with a novel instrumentation tool for performing cardio-electrophysiological studies at early developmental stages.”

Dr Elizabeth Rendon-Morales, a Research Fellow at the University of Sussex and lead author of the study, said: “With this research we wanted to push the frontiers of the EPS design towards its performance limits. Currently, heart-related diseases such as congenital cardiac arrhythmias and long/short QT syndrome cost the EU economy almost 196 million euros a year. It is vital for us to develop tools that help our professionals understand as much as possible. This research could potentially generate new insights into the origins of such heart abnormalities.”

The team is now designing a multiplatform based on EPS arrays for the recording of electrophysiological signals simultaneously, with possible applications in drug screening studies and neuroscience.

The EPS technology was originally developed out of research by Professor Prance, in collaboration with the Sussex Innovation Centre. A licensing agreement was signed in 2010 with Plessey Semiconductors to bring new applications to market, and it was shortlisted in the 2011 Times Higher Education Awards for technological innovation of the year.

Electric Potential Sensors (EPS) are wideband, ultra-high impedance sensors capable of detecting spatial potential, electric field or charge.