For individuals with bradycardia and other conditions that interfere with their heart’s rhythm, pacemaker surgery is a requirement. This procedure implants a device that regulates the heart rate and supports normal activities.
The treatment is life-sustaining, but as with all cell-powered implantable devices, a pacemaker battery is finite. This means that pacemaker replacement surgery is a periodic requirement for all permanent pacemaker patients.
However, the frequency of pacemaker replacement can be reduced with improvements to the tiny batteries that power these and other implants.
Through improved battery technology—and the switch from mercury-zinc batteries to lithium-iodide batteries—pacemaker battery life was extended from two years to as long as ten.
Other implantable device innovations have been explored, including a nuclear-powered pacemaker designed to last a lifetime, but the practicality of such options has been limited.
Using the body’s own energy sources as a type of pacemaker biofuel, however, may bridge the gap between safe and long-lasting in implantable device power cells.
Using Bio-Batteries In Heart Implant Devices
Glucose is a vital source of energy for many living things. Derived from carbohydrates, it fuels vital metabolic processes within the body.
This chemical energy could also be converted into electrical energy with the aid of the right fuel cell. Biofuel cells do this by utilizing natural sources of chemical energy to produce electrical current, and with energy storage potential that easily surpasses conventional batteries.
The components of the battery are an anode, cathode, separator, and electrolyte. The electrolyte is the conductive element that also contains the separator.
The separator prevents electrical shorts between the cathode and the anode, which direct the flow of the protons and electrons. Within this biofuel cell, glucose is oxidized at the anode to produce electrons and protons. This allows for the release of energy in the form of current.
The technology is decades old, but optimizing it to produce enough power on a small scale remains a challenge. Adding to this are the requirements for a bio-battery to safely function within the body.
Implantable fuel cells need to be biocompatible to ensure the body does not reject the device, that inflammatory responses are not triggered, and also that natural substances like proteins do not interfere with the battery’s functionality.
To overcome these obstacles, researchers have been exploring a few different technologies that show promise. One is a hybrid device that combines a supercapacitor with a tiny glucose fuel cell.
The addition of the supercapacitor allows for higher energy discharges to give the pacemaker enough power to sustain an adequate heart rate.
Other implantable glucose fuel cells use ceramics to create battery components that are small and resistant enough to facilitate higher power density.
Similar silicon chip-based glucose cells, which are meant for brain implants and nerve simulating devices, are further advancing self-powered medical technology.
The Benefits And Limits Of A Sugar-Powered Heart Battery
A pacemaker that’s essentially an instantly-recharging heart battery could theoretically eliminate the need for battery replacement.
If designs can be reliably scaled-down and power density is improved, glucose fuel cells could potentially become a standard in implantable devices. However, some fuel cell limitations go beyond the battery’s power source.
The components that comprise the battery, even if made from highly enduring and safe materials, will eventually wear down and affect the performance of the device.
In pacemakers, this can be life-threatening. Conventional pacemaker batteries can be a reliable indicator of device longevity, as this is usually the first element to gradually wear down.
When this starts to happen, a medical professional can easily identity the need for replacement long before the situation is critical. If pacemaker battery life becomes virtually limitless, another performance indication method will be required and replacement may still be necessary.
Remote device monitoring might serve as a solution, but this technology is not yet reliable enough for widespread integration.