Researchers at Rice University developed a tiny neurostimulation device that can be delivered intravascularly and which does not require a battery or wired connection. At approximately the size of a grain of rice, the device can be advanced through the vasculature until it lies near a target nerve, and a clinician can then attach it to the the vessel wall for long-term implantation. The stimulator is battery-free and is powered through an external magnetic transmitter. The researchers hope that the technology could lead to a replacement for bulkier neurostimulation devices that require on-board batteries or wires that penetrate the body.
Neurostimulation has the potential to kill pain or treat neurological disease, but current technologies have their limitationss, requiring invasive surgery for implantation and repeat surgeries to replace devices with old batteries. If a power source is external, it may require leads to penetrate the skin, with an accompanying infection and inflammation risk.
These researchers have taken a different approach, and have designed an implant that can be powered from outside the body, wirelessly. It can also be implanted through minimally invasive endovascular techniques, thanks in part to its small size. This approach involves using the blood vessels as a map, with the aim of reaching a target nerve.
“One of the nice things is that all the nerves in our bodies require oxygen and nutrients, so that means there’s a blood vessel within a few hundred microns of all the nerves,” said Jacob Robinson, a researcher involved in the study. “It’s just a matter of tracing the right blood vessels to reach the targets. With a combination of imaging and anatomy, we can be pretty confident about where we place the electrodes.”
The implant contains a strip of magnetoelectric film that can convert the energy from magnetic fields into electrical energy. The device can then be powered by an external magnetic transmitter that generates a magnetic field of approximately 1 milliTesla, which does not have adverse effects on underlying tissue.
“Because the devices are so small, we can use blood vessels as a highway system to reach targets that are difficult to get to with traditional surgery,” said Robinson. “We’re delivering them using the same catheters you would use for an endovascular procedure, but we would leave the device outside the vessel and place a guidewire into the bloodstream as the stimulating electrode, which could be held in place with a stent.”
Study in Nature Biomedical Engineering: A wireless millimetric magnetoelectric implant for the endovascular stimulation of peripheral nerves
Via: Rice University