Optimization of hydrogel-less metal electrode based system for portable continuous body water content monitoring

• Main Authors: You-Di Tseng, 曾友棣
• Other Authors: 廖國智
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/46648835662826350498

碩士 === 國立中興大學 === 生醫工程研究所 === 104 === The objective of the study is to verify the feasibility in applying hydrogel-less electrode for the development of bioimpedance based body water content monitoring . For dialysis and cardiorenal syndrome patients, it is critical to have point-of-care device providing continuously monitoring of the fluctuation of body water content for optimal management. The study was divided into five phases. In the 1st phase, we verified that hydrogel-less metal electrode can be applied to replace conventional hydrogel electrode for realizing the capability of continuously monitoring with Xitron Hydra 4200 bioimpedance spectroscopy and Medi-trace hydrogel electrode and Unimed Ag/AgCl hydrogel-less metallic electrode . In the 2nd phase, preliminary results indicated that lower arm was the preferential site for segmental detection than lower leg. The optimization of electrode miniaturization was investigated in the 3rd phase. With different reductions of contact surface areas (2×3, 2×2, 1.5×1.5, 1×1cm2), only 1×1cm2 group was observed exceeding error above 10%. 1.5×1.5 cm2 was considered the optimal contact surface area and applied in the following studies. The optimal length between input and output/detection electrode pairs was about 10-15 cm for achieving minimal detectable threshold value of Hydra 4200 with petite subject, and 12.5-15 cm was applied in the following studies adjusting the subject dependent factors. The optimal length inside each electrode pair was 2cm after non sensible deviation between the 4 experimental group (5cm, 4cm, 3cm, 2cm). The movement interference was found to be insignificant under 1 Hz hand waving in the 4th phase. In the 5th phase, the signal precision and reproduction was verified under continuously monitoring at 3, 6, 12, 24th hour.