Stretchable fractal electrodes integrated on miniature semi-expanded microballoon catheter for directional nerve stimulation

In recent years, the percutaneous balloon compression (PBC) does not require craniotomy and has gradually become the preferred treatment for trigeminal neuralgia. However, there is a lack of microballoon catheters with real-time feedback capability to replace the current personal experience from X-ray pictures. This paper reports a stretchable fractal electrode array integrated on miniature semi-expanded microballoon catheter for the first time, which can accommodate large expansion. Six electrode sites are uniformly distributed in 120 degrees circumferential direction on two ends of the microballon. Thus, the fractal electrodes can apply directional electrical stimulation with good spatial resolution to the compressed ganglion during the microballoon expansion, along with the evoked myoelectric potential to improve treatment of trigeminal neuralgia. Optimized fractal interconnects can integrate to the semi-expanded balloon with sufficient stretchability. Besides, the electrode sites with ring ground are assembled on metal marker rings without deformation for better nerve stimulation.