“We deliver them using the same catheters that you would use for an endovascular procedure, but we would leave the device outside the vessel and place a guide wire into the bloodstream as a stimulation electrode, which could be held in place. with a stent.”
The ability to power the implant remotely eliminates the need for electrical cables through the skin and other tissues. Wires used for devices such as pacemakers can cause inflammation and sometimes need to be replaced. Battery-powered implants may also require additional surgery to replace the batteries.
The researchers claim that ME-BIT’s portable charger could even be misaligned by several centimeters while providing sufficient power and programming to the implant, without irritating surrounding tissue.
“We’re getting more and more data showing that neuromodulation, or technology that acts directly on nerves, is effective for a wide range of disorders – depression, migraine, Parkinson’s disease, epilepsy, dementia, etc. – but it there is a barrier to using these techniques because of the risks associated with surgery to implant the device, such as the risk of infection,” said co-author Sunil Sheth, MD, associate professor of neurology and director of the vascular neurology program for McGovern Medical School at UTHealth Houston.
“If you can lower that bar and significantly reduce those risks using a wireless endovascular method, many people could benefit from neuromodulation.”
Electrical stimulation can reduce pain when doctors target the spinal cord and the dorsal root ganglia (DRG), a bundle of nerves that transmit sensory information to the spinal cord. But existing DRG pacemakers require invasive surgery to implant a battery and pulse generator.
By using blood vessels, the researchers say they can strategically place the ME-BIT implant in a minimally invasive way and achieve more predictable results.
“One of the good things is that every nerve in our body needs oxygen and nutrients, which means there’s a blood vessel a few hundred microns from every nerve,” Robinson explained. “With a combination of imaging and anatomy, we can be pretty sure where we’re placing the electrodes.
In a previous study, Robinson and his colleagues demonstrated the viability of the implants by placing them under the skin of fully awake laboratory rodents that were free to move about in their enclosures. The rodents preferred to be in parts of the enclosures where a magnetic field activated the implant, which provided a small voltage to the reward center in their brains.
Researchers need to conduct more animal studies and possibly human trials before seeking FDA approval for implants.
“We are conducting longer-term studies to make sure this approach is safe and that the device can stay in the body for a long time without causing problems,” said Sheth, who estimates the process will take a few years.