In early April 2025, a team of scientists announced the development of the world's smallest pacemaker—a device smaller than a grain of rice, designed to be injected into the body, controlled by light, and eventually dissolve. This wireless pacemaker aims to provide temporary heart rhythm regulation without the need for surgical implantation or removal. The device has been successfully tested in animal models, including mice, rats, pigs, and dogs, as well as on human heart tissue in laboratory settings. The researchers anticipate that human trials could commence within two to three years.

Traditional pacemakers are surgically implanted devices connected to the heart via leads (wires) to regulate electrical impulses. While effective, they carry risks such as infections, lead displacement, and complications during removal. Temporary pacemakers, often used post-surgery, require external power sources and transcutaneous leads, increasing infection risks.

The newly developed pacemaker introduces several groundbreaking features:

• Size and Delivery: Measuring just 1 millimeter thick and 3.5 millimeters long, the device is small enough to be delivered through a syringe, minimizing the invasiveness of the procedure.

• Wireless Operation: Unlike traditional pacemakers, this device operates without leads. It is powered by a galvanic cell that uses the body's fluids to convert chemical energy into electrical pulses, stimulating the heart as needed.

• Light-Controlled Functionality: The pacemaker is paired with a soft patch worn on the patient's chest. When the patch detects irregular heartbeats, it automatically emits light signals that instruct the pacemaker on the appropriate heart rhythm to stimulate.

• Biodegradability: Designed to dissolve into the body when no longer needed, the device eliminates the need for surgical removal, reducing potential complications associated with extraction.

The pacemaker has undergone successful testing in various animal models, including mice, rats, pigs, and dogs, as well as on human heart tissue in laboratory settings. These tests demonstrated the device's efficacy in regulating heart rhythms without causing harm. Researchers estimate that human trials could begin within two to three years.

The development of this pacemaker holds significant implications:

• Reduced Surgical Risks: The minimally invasive nature of the device's implantation and its biodegradability could lead to fewer surgical complications and infections.

• Accessibility: The device's small size and wireless operation may make pacemaker therapy more accessible to a broader range of patients, including those in remote or underserved areas.

• Advancements in Medical Technology: This innovation could pave the way for further developments in bioelectronic medicine, potentially leading to new treatments for various medical conditions.

Previous advancements in pacemaker technology include the development of leadless pacemakers like the Micra Transcatheter Pacing System, which is significantly smaller than traditional pacemakers and eliminates the need for leads. However, the new device surpasses these innovations by introducing light-controlled functionality and biodegradability, representing a paradigm shift in temporary pacing and bioelectronic medicine.

The development of this injectable, biodegradable pacemaker signifies a transformative breakthrough in cardiac care. By addressing the limitations of traditional pacemakers and introducing innovative features, this device holds the potential to revolutionize heart rhythm management, offering patients safer and more accessible treatment options.