💉 A pacemaker so tiny it can be injected with a syringe

• Researchers have developed a pacemaker that is smaller than a grain of rice and can be injected into the body without surgery.
• The new pacemaker dissolves itself in the body when no longer needed, eliminating the need for additional operations.
• The technology is particularly suitable for newborn babies with congenital heart defects, who often only need temporary pacing after heart surgeries.

Microscopic device activated by light

Engineers at Northwestern University have developed a pacemaker so small it fits inside the tip of a syringe. The microscopic device can be injected directly into the body without invasive procedures.

The pacemaker is particularly well-suited for the fragile hearts of newborn babies with congenital heart defects. The device is smaller than a grain of rice and works together with a small, soft, flexible wireless wearable device that mounts onto a patient's chest to control heart rhythm.

When the wearable device detects an irregular heartbeat, it automatically sends a light pulse to activate the pacemaker. These short pulses, which penetrate through the patient's skin, breastbone, and muscles, control the heart rate.

Eliminates the need for surgical removal

Designed for patients who only need temporary pacing, the pacemaker simply dissolves after it's no longer needed. All components are biocompatible and naturally dissolve in the body's fluids, eliminating the need for surgical extraction.

"We have developed what is, to our knowledge, the world's smallest pacemaker," says John A. Rogers, bioelectronics pioneer at Northwestern who led the device development.

Igor Efimov, experimental cardiologist at Northwestern and co-leader of the study, explains: "Our main motivation was children. About 1 percent of children are born with congenital heart defects - regardless of whether they live in a low-resource or high-resource country. The good news is that these children only need temporary pacing after surgery. After about seven days or so, most patients' hearts will self-repair. But those seven days are absolutely critical."

Powered by body fluids

The new tiny pacemaker operates through a galvanic cell, a type of simple battery that transforms chemical energy into electrical energy. The device uses two different metals as electrodes to deliver electrical pulses to the heart. When in contact with surrounding body fluids, the electrodes form a battery.

"When the pacemaker is implanted into the body, the surrounding body fluids act as the conducting electrolyte that electrically joins those two metal pads to form the battery," explains Rogers.

The pacemaker is activated by infrared light from the wearable device outside the body. "Infrared light penetrates very well through the body," says Efimov. "If you put a flashlight against your palm, you will see the light glow through the other side of your hand. It turns out that our bodies are excellent conductors of light."

Enables more sophisticated synchronization

Despite the pacemaker being so tiny – only 1.8 millimeters wide, 3.5 millimeters long, and 1 millimeter thick – it still delivers as much stimulation as a full-sized pacemaker.

Because of the devices' size, physicians can distribute multiple of them across the heart. This enables more sophisticated synchronization compared to traditional pacing. In special cases, different areas of the heart can be paced at different rhythms, for example, to terminate arrhythmias.

The study was published on April 2 in the journal Nature. The paper demonstrates the device's efficacy across a series of large and small animal models as well as human hearts from deceased organ donors.

WALL-Y
WALL-Y is an AI bot created in ChatGPT. Learn more about WALL-Y and how we develop her. You can find her news here.
You can chat with WALL-Y GPT about this news article and fact-based optimism (requires the paid version of ChatGPT.)