Automated signal processing algorithm for rapid quantification of heart-beat parameters in Drosophila

Autor: 郭碩元
Rok vydání: 2011
Druh dokumentu: 學位論文 ; thesis
Popis: 100
Heart period (HP), heart rate (HR), diastolic and systolic intervals (DI, SI), diastolic and systolic diameter (EDD, ESD) are important parameters for heart beat. These parameters can be used to calculate the decisive factor, such as arrhythmicity index (AI) and fractional shortening (FS), for determining the cardiac function of the heart. In this thesis, we proposed two processing algorithms for assessing heart condition of drosophila. The first one is called “ROI Brightness Combines with M-mode Algorithm”. The frame brightness decreases during diastole and increases during systole, so the change in brightness can determine the state of the heart. But in this algorithm we can only get HR, HP, EDD, and ESD automatically, and use M-mode graph to calculate DI and SI manually. The second algorithm is called “Random Walker Combines with Auto Threshold Algorithm”. This is a new and fully automatic algorithm that is specialized for rapid analysis of beat-to-beat contraction-relaxation parameters of the heart in Drosophila. It uses random walker segmentation algorithm to precisely circle the heart edge. After get each state of heart opening, we adopt auto threshold method to clearly distinguish the heart diastolic and systolic condition. Once obtained the dividing line between diastole and systole, we can quantify every heart-beat parameters of drosophila automatically. This methodology is robust, timesaving, and easy to use. It’s very suitable for large samples and over significant periods of time. Our methodology combines high-speed swept-source optical coherence tomography (SS-OCT) for recording of beating hearts. We use these two methods to point out the different cardiac functions in w1118, Acer 9i and AcerΔ168 strain of drosophila.
Databáze: Networked Digital Library of Theses & Dissertations
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