Regression Methods for Ophthalmic Glucose Sensing Using Metamaterials

Abstract

We present a novel concept for in vivo sensing of glucose using metamaterials in combination with automatic learning systems. In detail, we use the plasmonic analogue of electromagnetically induced transparency (EIT) as sensor and evaluate the acquired data with support vector machines. The metamaterial can be integrated into a contact lens. This sensor changes its optical properties such as reflectivity upon the ambient glucose concentration, which allows for in situ measurements in the eye. We demonstrate that estimation errors below 2% at physiological concentrations are possible using simulations of the optical properties of the metamaterial in combination with an appropriate electrical circuitry and signal processing scheme. In the future, functionalization of our sensor with hydrogel will allow for a glucose-specific detection which is insensitive to other tear liquid substances providing both excellent selectivity and sensitivity.

Highly Sensitive Refractive Index Sensors with Plasmonic Nanoantennas−Utilization of Optimal Spectral Detuning of Fano Resonances

“…An ideal system for our study is the structure depicted in Figure a, because it allows for good control of the single parameters, and it is well-described in the literature. , It consists of three gold nanoantennas repeated periodically in the x and y direction with period of 700 nm (in each direction). At the top of the system are two parallel antennas, which are exposed to the surrounding analyte.…”

Detection of Ethanol Concentration in Liquid Using a Double-Layered Resonator Operating at 5G-mm-Wave Frequencies

“…In Eq. 3, ϵ ' r is real permittivity, ϵ '' r is imaginary permittivity while f is the frequency that de nes the dispersive characteristics over the operating range of frequencies (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35). The instantaneous permittivity over the operating frequency range is measured because materials' permittivity exhibit a frequency dispersive phenomenon at high frequencies.…”

Dynamic modeling of the hydrogel molecular filter in a metamaterial biosensing system for glucose concentration estimation

“…The eye-lentil unit (I) is simulated using scattering matrix theory to calculate reflectance, transmittance, extinction and absorption spectra of metallic structures [10]. Additionally, information about the electric and magnetic field distribution can be obtained.…”

“…1, measured signals are conditioned to estimate the tear glucose levels via an developed inverse model of the system consisting of metamaterial, hydrogel, LED, photodiodes and disturbances. The main reasons why this new method has the potential to be extremely successful are its selectivity to glucose, guaranteed through the hydrogel; further its sensitivity in the physiological range that is accomplished by the metamaterial; its biocompatibility due to the characteristics of the noble metals of the metamaterial, and its non-degrading during the lifetime of the sensor [9], [10].…”