Workshop in Computer Science Multivariate Modeling Sound and Interactive Multi-Media 0368-3500-07, Autumn 2004-5 Prof. Nathan Intrator Reuven Aronashvili Oded Ashkenazi

Flow Diagram Musical Effects

Introduction

ECG Analyzer The parameters from left to right are: R to R time in milliseconds. R to R time normalized. Variance of the R peaks amplitude. S to S time in milliseconds. S to S time normalized. Variance of the S peaks amplitude. Variance of the T peaks amplitude. T – S amplitude values.

Normalizing Output The Temporal parameters are shown twice. Once in milliseconds, and once Normalized by dividing by twice their mean. Resulting in range of [0,1] around 0.5. The Amplitude parameters are normalized by dividing by the signals std. (The mean of the signal is 0)

Theory and Algorithms Temporal features Amplitude features

Temporal features Example: Calculating R – R time Select the top 13% of the signal Reduce to zero ECG signal from Digitizer~ Signal from R_Peaks

Amplitude features We use the timing from the temporal features to open a window and capture the wanted values into signals. (R, S and T) We measure the difference between those signals maximum and minimum.

Example: T wave ECG signal from Digitizer~ Signal after 75% cutoff Maximum in each time frame (R & T)

How To Use ? 2 1 3 4 5

How To Use ? Instructions: First install the digitizer. Select ECG input source. (Left for digitizer / right for raw input file). Turn Patch ON. (Light should turn red). If input is a raw file, click Load File and select a raw float64 file. Press PLAY. (Light should turn green). Wait 60 seconds until results start coming.

Next Step - Music The Parameters are passed on to Max/MSP object created by Mor and Shahar. These affect the music in such a way that will result in an accurate biomedical feedback.

The Fun Part Presentation of live data. Lets connect Oded…