New Research Develops Pacemaker Without Batteries Powered by Light

Pengju Li and his colleagues at the University of Chicago have created a wireless, ultrathin pacemaker that functions similarly to a solar panel by utilizing light. Because it conforms to the shape of the heart, its design reduces interference with the heart’s normal function while simultaneously doing away with the need for batteries. Their findings, which were just released in the journal Nature, provide a novel strategy for heart pacing and other therapies requiring electrical stimulation.

Medical devices called pacemakers are inserted into the body to control cardiac rhythms. They are made up of battery-operated electrical circuits with leads that are fixed to the heart muscle to stimulate it. Leads, however, can break and cause tissue damage. Once implanted, the leads’ position cannot be altered, which restricts access to various cardiac areas. Pacemakers might cause tissue injury when they are used in regulating arrhythmia or restart the heart after surgery because they use stiff iron electrodes.

The group’s aim was for a more adaptable, leadless pacemaker that could accurately stimulate various heart regions. Thus, they created a device that converts light into bioelectricity, or electrical signals produced by heart cells. The pacemaker is constructed of silicon membrane and optic fiber, which the Tian lab and colleagues at the University of Chicago Pritzker School of Molecular Engineering have spent years developing. It is thinner than a human hair.

This pacemaker is driven by light, just like solar panels.

To accurately regulate heartbeats, they changed their device to create power only at points where light strikes, in contrast to normal solar cells, which are typically designed to capture as much energy as possible. A coating of minuscule pores, capable of capturing both light and electrical current, was employed to achieve this. Only heart muscles that are in contact with pores triggered by light are stimulated.

The gadget may be implanted without opening the chest because it is so lightweight and compact. It was successfully implanted, timing the beats of several cardiac muscles in the hearts of mice and an adult pig. Given the structural similarities between pig and human hearts, this achievement shows the device’s potential human application.

Why It Matters. Globally, heart disease is the primary cause of death. Over two million people have open heart surgery each year to treat cardiac conditions, including the implantation of devices that control cardiac rhythms and stave off heart attacks.

With its innovative, ultralight design, the heart’s surface may be gently conformed to for less intrusive stimulation, better pacing, and synchronous contraction. A minimally invasive procedure can implant the device, reducing postoperative trauma and recovery time.

What Still Isn’t Known. At the moment, ventricular defibrillation, heart attacks, and heart restarts are the situations in which the technique works best when used initially. The research team is still investigating its durability and long-term consequences in the human body.

The heart’s continuous mechanical action disturbs the body’s interior environment, which is rich in fluids. Over time, this can jeopardize the functionality of the device.

The body’s response to extended exposure to medical equipment is still not well understood by researchers. After implantation, scar tissue may grow around the device, reducing its sensitivity. To reduce the possibility of rejection, they are creating unique surface treatments and biomaterial coatings.

While silicic acid, a harmless material the body may safely absorb, is produced when the device breaks down, it is crucial to assess the body’s reaction to prolonged implantation to guarantee both safety and efficacy.

What’s Next? The rate at which the device dissolves naturally in the body is being fine-tuned by the researchers to accomplish long-term implantation and customize the device to each patient. To enable it to function as a wearable pacemaker, improvements are being investigated. This entails incorporating a wireless light-emitting diode, or LED, under the skin that is optically coupled to the apparatus.

Their ultimate aim is to extend the use of what they refer to as photoelectroceuticals outside of cardiac treatment. This covers the treatment of neurodegenerative diseases, including Parkinson’s disease with neurostimulation, neuroprostheses, and pain management.