By Srishti Malaviya:
“Oh what’s this? Is this my heart?
And is it thumping?…Oh sleepy heart what do you say?
Should we keep thumping?”*
Creation is no longer solely a divine project. Technology has, very aptly indeed, assumed in part Nature’s burden of creating, nurturing and sustaining life. Certainly a model heart that simulates the human heart’s astounding complexity in all its sophistication, moves and twists included, is a whole new dimension. A team of researchers at Harvard School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering at Harvard University have given the medicine community a reason to celebrate by developing a low-cost, programmable, soft actuated material-made model of the heart. What makes this feat even more laudable, and yes touching too, is the 3D facet of this robotic heart!
A healthy human heart, in its 3D motion, circulates blood through a twisting movement rather than a simple pumping action. What scientists have termed the ‘left ventricular twist’ is the course of the process, through which the heart efficiently pumps blood. While the top-half of the heart twists in a clockwise direction, the bottom-half twists counter clockwise, contracting all the way. The heart owes this action to bundles of striated muscle fibers, spirally bound in the same direction, that together help produce the heart’s motion. This complex movement also serves as an indicator of health.
For long, engineers and scientists have sought to develop robotic models that can replicate these intricate moves of human muscles but have largely stopped short of reproducing the vast complexity of the natural systems, at least in this regard. Ellen Roche, lead author of the research on the model in question, claims that, “most models of the heart used today do not mimic its 3D motion”, in that by focusing solely on the blood flow they overlook the essential twisting motion of the heart. Until now.
The model heart comprises tube-like pneumatic artificial muscles (PAMs) that shorten under pressure in the same direction, rather like biological muscles. These PAMs when placed within a matrix — made of the same soft material as the artificial muscles i.e. silicone elastomer with embedded braided mesh — reproduced the same twisting movement of the heart when faced with external pressure and changes induced in their orientation and configuration within the matrix. Further, the team also developed a computer model of this heart that emulates the related movement of these PAMs in 3D. Also, the team was successful in imitating the sort of damage certain diseases inflict upon the heart muscles, by selectively disabling certain PAMs within the matrix.
By testing this artificial device in 3D, the team has accomplished a groundbreaking innovation since most mechanical cardiac devices today are tested in 2D.This should help open up many new avenues in research in this field, providing a model that promises greater efficiency in testing such devices. The team of innovators envisions this as the first in a series of steps that would eventually culminate in the production of a new and much more nuanced implantable cardiac devise. The immediate next task for them is to create biocompatible varieties of the matrix.
A happy story of technological breakthrough that warms the heart!
*These lines can be heard in Mount Eerie’s heartbreaking rendition of the song “O My Heart”.