International Conference on Mechanical, Industrial and Materials Engineering 2013 (ICMIME2013) 1-3 November, 2013, RUET, Rajshahi, Bangladesh. Page | 783 Paper ID: RT-05 Analyzing Energy Drinks Effect on Respiratory and Cardiac Function by Wavelet Transforms Using Laser Doppler Flowmetry Md. Nafiur Rahman Protik 1 , Fatema Khatun 2 , Muhammad Muinul Islam 3 1,2 Dept. of Telecommunication and Electronic Engineering, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh 3 Dept. of Biomedical Engineering, Khulna University of Engineering and Technology, Khulna-9203, Bangladesh E-mail: protik69@hotmail.com, fatema.tee.08@gmail.com, mmi.kuet@gmail.com Abstract Wavelet transform was used to analyze the effect of having energy drinks (ED) on respiratory and cardiac functions. Laser Doppler Flowmetry technique LDF100C (Biopac systems Inc.) was used on 12 healthy human subjects to analyze the effect of having energy drinks. After having energy drinks, by spectral analysis of LDF signal, it is observed that the amplitude of blood perfusion signal was increased. The physiological activities which include the frequency interval studied from 0.0095- 1.6 Hz was divided into five subintervals. Among them respiratory function due to 0.15-0.4 Hz and cardiac function due to 0.4-1.6 Hz , was measured in BPU2/Hz before and after having energy drinks. Discrete Wavelet transform was used for further analyzing frequency spectrum of the blood perfusion signal. A significant change was observed in these activities after having energy drinks. The amplitude of frequency spectrum of LDF signal related to respiratory activity increases around two fold. A little change was observed in cardiac function. Keywords: AcqKnowledge software, Blood perfusion signal, Energy drinks, Laser Doppler Flowmetry, Wavelet analysis. 1. Introduction The laser Doppler flow signal from the skin generally contains constant and oscillatory components. Cyclical flow variations have different periods (and frequencies), according to their origins. Spectral analysis has been used to identify six frequency bands, around 0.009 Hz, 0.01 Hz, 0.04 Hz, 0.1 Hz, 0.3 Hz and 1 Hz. Among them 0.3 Hz and 1 Hz, whose origins are known as respiratory and cardiac, respectively [1]. In addition, the cardiac and respiratory rhythms have been detected in the regions around 1 and 0.3 Hz in human skin [2]-[6]. Today energy drinks become the latest craze and a permanent fixture in our culture. An energy drink is a beverage that contains some form of legal stimulant and/or vitamins which are supposed to give consumers a short term boost in energy. Make a mental note that while the Food and Drug Administration (FDA) is allowing companies to sell and market their energy drink products, there is still very little research that has been done on them. It is suspected that the FDA allows them to be added simply because they do not pose any immediate danger to energy drink consumers [7]. The aim of the study is to determine the microvascular changes in the periodic oscillations of cutaneous blood perfusion after having energy drinks using Laser Doppler Flowmetry Technique. We hypothesized that having energy drinks changes in microvascular control mechanisms of the skin would result in differences in the spectral components and their corresponding amplitudes. 2. Materials and Method Laser Doppler Flowmetry The LDF technique takes advantage of the Doppler Effect, which is seen as a frequency shift in coherent monochromatic light waves scattered from moving red blood cells (erythrocytes) in the blood [7]. A LDF device uses two laser probes, one is the light-emitting probe and the other is the receiving probe [8]. The principle of laser Doppler Flowmetry technique is shown in Fig. 1, where low power laser light is used to illuminate tissue using a fiber optic; the light is scattered by the static tissue structures and moving blood cells; the moving blood cell impart a Doppler Shift; an adjacent fiber detects light returned from the tissue; this light contains Doppler shifted and unshifted light; the signal is processed to extract the signal related to the moving red blood cells [9].