Design of portable integrated diode-based biosensor for diabetic diagnoses

Abstract

We propose a technique that integrates pnjunction light emitting diodes and Schottky diode photo detectors operating in the visual spectrum (450 - 750nm) in a CMOS process that will output results to an RFID system. This technique relies on known absorption and scattering functions in the epidermis, dermis and subcutaneous tissues for diabetic diagnoses. The suggested wristwatch-type system consists of an arrays of pn-junction diode for emitting light, CMOS Schottky diodes for detecting light, a signal processing unit, a warning signal generation unit, and an RFID chip with antennae. The main features of this system are monitoring the glucose level by a non-invasive and continuous manner and a wireless communication between the device and an RFID reader, which also has an ability to make a phone call. When the glucose level reaches a critical level, the patient receives a warning signal, and, at the same time, the reader calls an emergency number automatically. Due to the low fabrication cost, the suggested system can be inexpensively manufactured so that it can be used for in-home monitoring of the glucose level of a patient. Additional post-processing may be required to calibrate the device to account for variations in epidermal properties between individual patients. The future extensions of this device can be applied to cardiac and temperature monitoring mechanisms to be used in a portable health monitoring system.