Application of Reflectance Mode Photoplethysmography for Non-Invasive Monitoring of Blood Glucose Level with Moving Average Filter

With the continuous increase in number of people suffering from diabetes, the demand of a device that can noninvasively monitor blood glucose level has been greater. The goal of the study is to develop a device that can monitor the blood glucose level that would not cause any discomfort to the patients by utilizing reflectance mode photoplethysmography equipped with a filtering technique, Moving Average filter. Initially, the device prompts the user to choose from two categories depending on his condition: diabetic or non-diabetic, and then would choose between the two modes: fasting or post meal mode. The parameters utilized in the study are the force in Newton (N) which corresponds to the applied pressure on the finger, the peak-to-peak voltage (V) of the photopletyhsmography signal, and lastly, the blood glucose level measured in milligram per deciliter (mg/dL). The force is acquired using a force sensitive resistor that is incorporated in the ring. The suggested device employs a photoplethysmography sensor which can diagnose variations on microvascular bed of tissue. The variations in the distribution of blood volume have a significant relation with the measurement of blood glucose level. The technique used to estimate the photoplethysmography in terms of peak-to-peak voltage is the Moving Average filter, and the result is then compared to that of the OneTouch glucometer and Fasting Plasma Glucose. From the results acquired, two equations are derived which output the blood glucose level for diabetic and non-diabetic patients in mg/dL. The equations are described to be both linear, a positive correlation for non-diabetic patients with a percentage of 70.3004% and a negative correlation for the diabetic with a percentage of 91.9226%.