6.111 Final Project Presentation:Wireless EKG AnalyzerMotivationSystem ArchitectureWireless transmissionFFT – Fast Fourier TransformFFT – How it worksFFT AlgorithmFFT – Interface with systemDisplay6.111 Final Project Presentation:Wireless EKG AnalyzerApril 21st, 2004Team members:Vanessa Hsu ChenDerik ThomannMotivation Remote monitoring of vital signs in patients by wireless transmission of useful data Analog inputs of system are medical sensors: In our case, EKG: Electrocardiogram: electrical recording of the heart Another possibility, Digital Stethoscope: supervising of breathing patternsSystem ArchitectureWireless transmission Transmits 10 bit EKG Data from 1 to 2, sampled using on board ADC Transmits Help signal (button) from 1 to 2 Transmits Acc signal (button) from 2 to 1 Outputs dataavail when data is ready, help when help signal is activated, and 10 bit data to FFT moduleFFT – Fast Fourier Transform Why? Signal in frequency domain - in order to do spectral analysis DFT – equally spaced samples of DTFT FFT – for powers of 2 number of sampleswhereand WNare the roots of unity in the unit circleFFT – How it works Use divide and conquer For 2 points: For 4, pre-compute thepairs and add themFFT Algorithm Use algorithm from “Numerical Analysis” by Burden and Faires Basically, two separate loops: one to pre-compute the pairs and add, and one to move to correct coefficient order Controlled by a major FSM which stores the data in memory and interfaces with other system components Individual FSM for each separate loop that controls the behavior of the algorithmFFT – Interface with system Receives ready signal and 10-bit sample data from wireless base station. Sends a /busy signal to the base station Sends a data ready signal to the output display, along with two data buses: one with the input sample, and one with its FFT computed Also passes help/acknowledged signals between sensor and displayDisplay Receives and displays Original EKG data and Power spectrum (FFT data) Displays using MC6847 low resolution in color EKG data traced scope-like, FFT data refreshed and displayed Serial Data transfer accomplish by Data
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