When it comes to monitoring the electrical activity of the heart, or delivering electrical stimulation to it (as in the case of pacemakers), most current technologies rely on electrodes that make contact with the organ in just a few locations. That doesn't necessarily provide a very detailed picture of what's going on, nor does it deliver stimulation all that evenly. Now, scientists have created a sensor-laden three-dimensional elastic membrane that can be pulled over the whole heart, to provide a large number of contact points.
The device was created by an international team of scientists led by Dr. Igor Efimov at Washington University in St. Louis, and Dr. John Rogers at the University of Illinois at Urbana-Champaign.
To create the experimental prototype, they started by scanning a rabbit's heart. With human patients, this could be done via MRI or CT scan. Using that data, they proceeded to create a 3D-printed life-size model of the heart – not unlike the one recently created at the University of Louisville, to aid in heart surgery on a child. That model was then used to mold the membrane, to ensure a custom fit over the epicardium (the outer wall) of the real heart. The tiny interconnected sensors embedded in the membrane were applied using a transfer printing technique.
Finally, the membrane was pulled onto the heart, which was made to beat in a lab test.
Along with electrodes for stimulating the heart to correct arrhythmia, clinical versions of the membrane could also include sensors for monitoring parameters such as temperature, mechanical strain, pH or troponin levels, the last of which is a protein which indicates that a heart attack is imminent.
Additionally, the membranes could be fitted to other organs besides the heart. On the kidneys, for instance, they could be used to monitor concentrations of calcium, potassium and sodium.
A paper on the research was published this week in the journal Nature Communications.