In my lifetime, artificial pacemaker technology has evolved from an external device with vacuum tubes that powered up via a wall socket to today’s tiny implantable devices with batteries that run for five to 10 years. That is pretty remarkable progress, but as any engineer will tell you, there is always room for improvement. Enter the Heart-Beat Scavenger (HBS) consortium, spearheaded by the Grenoble-based R&D body Leti. The group’s mission is the development of a self-powered cardiac pacemaker that is eight times smaller than current models. If successful, the project will have a tremendous impact on patient care and health economics, since it will eliminate the need for additional surgical procedures to replace batteries.
Leti is responsible for the development of a prototype to harvest the mechanical energy produced by the movements of the heart and a capacitance conversion system. The Sorin Group, which is also an HBS member, ultimately would commercialise the device.
Advances in miniaturisation, power consumption of electronics and energy harvesting have paved the way for the development of self-powered implants, says Leti Project Manager Jean-Jacques Chaillout. “Photovoltaic harvesting and thermoelectricity are not viable technologies for applications where temperatures are uniform or the environment is dark,” he explains. “That is why we are focusing on harvesting mechanical energy produced by the movements of the heart.” The biggest challenge, adds Chaillout, resides in producing the requisite amount of energy within the application’s specified volume. As for the capacitance conversion system, these features are just being identified and remain confidential for the time being, he explains.
Beyond the energy harvesting and storage breakthroughs, size reduction also will have a decisive impact. By shrinking the size of the pacemaker from 8 to 1 cm3, the device can be directly attached inside the heart by the intravenous introduction of cardiac probes.
The HBS project has a three-year duration, and industrialisation is expected within eight years. The research has ramifications well beyond its application in implantable pacemakers, Chaillout adds. “Mechanically derived energy is ubiquitous and the energy does not generate pollutants, so it is consistent with eco-design principles. Hence, its application fields are vast and are not limited to medical devices.”
For now, though, we will be more than satisfied to reap the technology’s medical benefits, and I, for one, wish the group success in its endeavour with all my heart.