Engineers Unveil World's Smallest Cardiac Pacemaker
- 21 oct
- 2 Min. de lectura
Northwestern University engineers have unveiled what is believed to be the world’s smallest cardiac pacemaker, a groundbreaking device set to revolutionize temporary heart care. Developed by bioelectronics pioneer John Rogers, PhD, and experimental cardiologist Igor Efimov, PhD, this new device is so minuscule—smaller than a single grain of rice, measuring just 1.8 mm x 3.5 mm x 1 mm—that it can be non-invasively injected into the body using the tip of a syringe needle.
The motivation behind this extreme size miniaturization was primarily pediatric care. About 1% of children are born with congenital heart defects, and many require temporary pacing for crucial periods (around seven days) after surgery until their hearts self-repair. According to Dr. Rogers, “There’s a crucial need for temporary pacemakers in the context of pediatric heart surgeries... the smaller, the better”.
Conventional temporary pacemakers involve invasive or less-invasive surgeries and require wires that protrude from the patient’s chest, connecting to an external pacing box. When these traditional devices are removed, potential complications include infection, bleeding, torn tissues, or dislodgement, a risk underscored by the tragic case of Neil Armstrong, who experienced fatal internal bleeding when his temporary pacemaker wires were removed.
In stark contrast, the new device is designed to simply dissolve once it is no longer needed. All components are biocompatible and naturally resorb into the body’s biofluids, bypassing the necessity for a secondary surgical extraction procedure.
To achieve such small dimensions, the Northwestern team innovated its power and control mechanisms, moving away from the near-field communication (NFC) protocols that limited the size of their previous dissolvable pacemaker prototype.
The new, tiny pacemaker is wireless and paired with a small, soft, flexible, wearable device that mounts onto the patient’s chest. When this wearable sensor detects an irregular heartbeat, it automatically shines short infrared light pulses through the skin and muscle to activate the pacemaker. The team utilized infrared light because it penetrates deeply and safely into the body.
Furthermore, the device draws power from the body itself. It operates via a galvanic cell—a type of battery—formed by two different metal electrodes. Once implanted, the surrounding biofluids act as a conducting electrolyte that forms the battery, allowing the device to deliver electrical stimulation pulses to the heart.
Despite its size, the pacemaker delivers stimulation equivalent to a full-size device. Its miniaturization simplifies procedures, reduces trauma, and eliminates the risks associated with removal.
The versatility of this technology is extensive. Physicians could distribute collections of the tiny pacemakers across the heart to achieve more sophisticated synchronization, or the devices could be integrated into other medical implants, such as transcatheter aortic valve replacements, to address immediate post-procedure complications. The concept of bioresorbable electronic medicine developed by Rogers’ lab also opens possibilities for future applications in helping nerves and bones heal, treating wounds, and blocking pain.
The technology has been successfully tested in both large and small animal models, as well as human hearts from deceased organ donors. Dr. Rogers projects the device could enter clinical trials within approximately five years, marking it as potentially the first resorbable electronic device used in a clinical setting.
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