| 초록 |
We present a parylene C-based flexible electrode composed of two thermocouples and bipolar radio frequency (RF) electrodes for laparoscopic renal denervation catheter. Renal sympathetic denervation (RDN) system deliver RF energy to the renal nerves in the endothelial layer of an artery. The purpose of RDN is to interrupt the sympathetic nerve signal from brain to kidneys for the treatment of resistant hypertension. The proposed laparoscopic renal denervation catheter consist of flexible electrode formed on shape-memory alloy (SMA), catheter rod, and Handle part. The parylene C-based flexible electrode fabricated by MEMS technique has a function of ablation and real-time temperature monitoring. A pair of RF ablation electrode (Au in thickness of 300nm) and t-type thermocouple temperature sensor (Cu & Cu55%Ni45% in thickness of 300nm for each metal) were embedded to parylene C in thickness of 20um. The parylene C polymer as a substrate material was employed for electrically insulation and flexibility. Anisotropic conductive film (ACF) bonding technique to transfer electrical signal was used to bond the customized flexible printed circuit board (FPCB) with parylene C-based flexible electrode. In the measurement results, the temperature coefficient of the two MEMS thermocouples was 38.3 µV/°C and 38.5 µV/°C, similar to that of commercialized T-type TC (40.2 µV/°C). The correlation coefficient between the MEMS thermocouples and the commercialized TC was extremely close to unity (R2=0.999). We also tested the mechanical durability of parylene C-based flexible electrode during the wrapping and unwrapping process of laparoscopic RDN. Over 1000 bending cycles, the temperatures of the MEMS thermocouples varied by 0.44 and 0.49 °C, respectively. |
