Improvement of Depth Profiling into Biotissues Using Micro Electrical Impedance Spectroscopy on a Needle with Selective PassivationReport as inadecuate


Improvement of Depth Profiling into Biotissues Using Micro Electrical Impedance Spectroscopy on a Needle with Selective Passivation


Improvement of Depth Profiling into Biotissues Using Micro Electrical Impedance Spectroscopy on a Needle with Selective Passivation - Download this document for free, or read online. Document in PDF available to download.

1

Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology GIST, Gwangju 500-712, Korea

2

School of Mechanical Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea





*

Author to whom correspondence should be addressed.



Academic Editors: Eiichi Tamiya, Yuji Murakami, Tatsuro Endo and Mun’delanji Vestergaard

Abstract A micro electrical impedance spectroscopy EIS-on-a-needle for depth profiling μEoN-DP with a selective passivation layer SPL on a hypodermic needle was recently fabricated to measure the electrical impedance of biotissues along with the penetration depths. The SPL of the μEoN-DP enabled the sensing interdigitated electrodes IDEs to contribute predominantly to the measurement by reducing the relative influence of the connection lines on the sensor output. The discrimination capability of the μEoN-DP was verified using phosphate-buffered saline PBS at various concentration levels. The resistance and capacitance extracted through curve fitting were similar to those theoretically estimated based on the mixing ratio of PBS and deionized water; the maximum discrepancies were 8.02% and 1.85%, respectively. Depth profiling was conducted using four-layered porcine tissue to verify the effectiveness of the discrimination capability of the μEoN-DP. The magnitude and phase between dissimilar porcine tissues fat and muscle were clearly discriminated at the optimal frequency of 1 MHz. Two kinds of simulations, one with SPL and the other with complete passivation layer CPL, were performed, and it was verified that the SPL was advantageous over CPL in the discrimination of biotissues in terms of sensor output. View Full-Text

Keywords: electrical impedance spectroscopy; hypodermic needle; interdigitated electrodes; selective passivation; depth profiling; biotissues electrical impedance spectroscopy; hypodermic needle; interdigitated electrodes; selective passivation; depth profiling; biotissues





Author: Joho Yun 1, Hyeon Woo Kim 1 and Jong-Hyun Lee 1,2,*

Source: http://mdpi.com/



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