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Unformatted text preview: GEORGIA INSTITUTE OF TECHNOLOGY SCHOOL of ELECTRICAL and COMPUTER ENGINEERING ECE 2025 Spring 2009 Lab #12: (B) Interference Removal from Electro-Cardiogram (ECG) Signals Date: 15-21 April 2009 The Warm-up section of each lab must be completed during your assigned Lab time . After completing the warm-up section, turn in the verification sheet to your TA. No lab report is required. 1 Course Opinion Surveys Please complete three surveys: one survey in ITS and two Georgia Tech surveys, one for your Recitation and one for Lecture: https://gtwebapps.gatech.edu/cfprod/cios_new/ Instructor Verification (separate page) 2 Warm-up: Introduction A common heart test is an electrocardiogram (ECG) which records electrical activity that changes during the cardiac cycle. Metal electrodes placed at several locations on the body “pick up” these cardiac electrical signals. Unfortunately, these electrodes also pick up signals from other electrical sources, most notably harmonics of the 60-Hz power signal (or 50-Hz in some other countries). The objective of this short lab is to show that you can remove a sinusoidal interference from a corrupted ECG signal, and produce a cleaned-up signal. This will tap into your 2025 skills as an accomplished “filter designer.” 2.1 IIR Notch Filters An IIR notch filter will null out one frequency, while having a frequency response that is relatively flat across the rest of the frequency band. It has one complex zero pair and one complex pole pair. Zeros at e ˙ j Poles at re ˙ j where r is a number slightly less than one. Thus the system function is: H.z/ D B.z/ A.z/ D G .1 e j z 1 /.1 e j z 1 / .1 re j z 1 /.1 re j z 1 / (1)...
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