ADBB1D16d01 - IEEE Transactions on Dielectrics and...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
IEEE Transactions on Dielectrics and Electrical Insulation Vol. 13, No. 2; April 2006 1070-9878/06/$20.00 © 2006 IEEE 247 An RCL Sensor for Measuring Dielectrically Lossy Materials in the MHz Frequency Range 1. Comparison of Hydrogel Model Simulation with Actual Hydrogel Impedance Measurements M.S. Talary, F. Dewarrat, A. Caduff Solianis Monitoring AG. 8050 Zürich, Switzerland A.Puzenko, Y. Ryabov, and Y. Feldman Department of Applied Physics The Hebrew University of Jerusalem Jerusalem 91904, Israel ABSTRACT There is a requirement for the development of non-invasive continuous blood glucose monitoring devices to meet the clinical demands of the rapidly increasing number of people currently developing diabetes mellitus. Impedance Spectroscopy is a technology that meets the requirements of such devices. An NI CGMD is being developed as a device that couples a sensor to the skin to form an RCL sensor. The reliability of such an RCL sensor model has been investigated by comparing electrodynamical simulations to in-vitro measurements of dielectrically “lossy” materials. The sensor has been modeled and simulated in FEMLAB (Finite Element Modeling Laboratory). In-vitro measurements are performed on hydrogels, representing the lossy material, by the aid of a Rohde & Schwarz VNA (vector network analyzer). From the quantitative agreement of the results we conclude, that the proposed qualitative model is appropriate for the characterization of the RCL sensor and suggests that more detailed models can be used to elucidate the behavior of human skin tissue. Index Terms - Equivalent circuits, circuit simulation, transducers, dielectric measurements, dielectric materials, skin, medical diagnosis. 1 INTRODUCTION DIABETIS mellitus is a metabolic disease that can lead to uncontrolled glucose excursions. There is an increasing interest in the closer monitoring of glycaemic conditions to reduce the incidence of complications associated with prolonged hyper or hypo-glycaemic excursions, preferably in a non-invasive and continuous manner. Due to the known specific reactions of blood and tissue cells on a varying glucose concentration, the electrolyte balance across membranes of cells in blood and underlying tissue is changed as a function of glucose. Dielectric spectroscopy (DS) or Impedance Spectroscopy (IS), as a more recognized term in the bio-impedance community, is thought to be sensitive to these subtle changes. In this work, we investigate the feasibility of using DS techniques to monitor changes in complex human biological systems due to the alteration in blood glucose levels. It has been previously reported that a non-invasive, continuous glucose monitoring device (NI-CGMD) is being developed using impedance spectroscopy to provide real time monitoring of glucose levels in human tissue [1]. This NI-CGMD consists of a sensor capacitively coupled to the body, a signal generator operated in a selected frequency range (1 – 200 MHz) and a microprocessor that controls the operation of the device. The
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 10

ADBB1D16d01 - IEEE Transactions on Dielectrics and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online