It’s a tiny device with a life-changing function: Engineers at Northwestern University have developed a dissolvable pacemaker so minuscule that it fits inside the tip of a syringe. The light-activated cardiac regulator advances medical capabilities for the smallest patients, as its microscopic size makes it ideally suited for the delicate hearts of newborns.
The pacemaker uses a galvanic cell, a battery formed by two metal electrodes interacting with the body’s biofluids, to convert chemical energy into electrical pulses for heart stimulation. It was designed to be paired with a small, soft, flexible, wireless, wearable device that mounts onto a patient’s chest to control pacing.
When the wearable detects rhythm disturbance, it automatically shines a light pulse to activate the pacemaker. Northwestern University reports that these pacemakers were inspired by babies, and developed specifically for patients requiring only short-term cardiac pacing. What’s more, the device naturally dissolves into the body’s biofluids once it’s no longer needed, bypassing the need for surgical extraction, which can cause complications.
“We have developed what is, to our knowledge, the world’s smallest pacemaker,” said Northwestern bioelectronics pioneer John A. Rogers, who spearheaded the device development. “There’s a crucial need for temporary pacemakers in the context of pediatric heart surgeries, and that’s a use case where size miniaturization is incredibly important. In terms of the device load on the body—the smaller, the better.”
As Cardiac Innovations Evolve, Standards Provide the Foundation
Did you know that pacemakers and other cardiac support devices utilized daily by physicians worldwide depend on several key standards for safety, functionality, and interoperability? Common standards that support life-preserving devices include ISO 14708-2:2019, Implants for surgery — Active implantable medical devices, Part 2: Cardiac pacemakers. This standard specifies requirements that are applicable to those active implantable medical devices intended to treat bradyarrhythmias and devices that provide therapies for cardiac resynchronization.
Other standards, ISO 5841-2:2014 and ISO 5841-3: 2014, cover implants for surgery. The International Organization for Standardization (ISO) Technical Committee (TC) 150, Implants for surgery, Subcommittee (SC) 6, Active implants, for which the U.S. serves as Secretariat, developed these three standards and several other standards related to cardiac devices. AAMI is the ANSI-accredited U.S. Technical Advisory Group (TAG) administrator for ISO TC 150 SC 6.
A blood pressure test, usually taken with a blood pressure cuff, measures the pressure in the arteries as the heart pumps. IEEE 1708-2014, IEEE Standard For Wearable Cuffless Blood Pressure Measuring Devices, establishes a normative definition of wearable cuffless blood pressure-measuring devices and the objective performance evaluation of this kind of device. This standard was developed by Institute of Electrical and Electronics Engineers (IEEE), a member and ANSI-accredited standards developer.
ASTM F2914-12(2018), Standard Guide for Identification of Shelf-life Test Attributes for Endovascular Devices, addresses the determination of appropriate device attributes for testing as part of a shelf-life study for endovascular devices. ASTM International, an ANSI member and audited designator, developed this standard in addition to a number of cardiovascular standards related to stents and blood pumps.
These are just a sampling of various standards that support healthy hearts. Read more about Monitoring Your Cardio Health (and Standards that Help).
Read more about the tiniest pacemaker and its innerworkings via Northwestern University’s April 2025 news or listen to a podcast on the pacemaker’s development.