ADVANCED DIGITAL STETHOSCOPE PHASE I SECOND REVIEW BY E.MURUGA LAKSHMI (ROLL NO:12) Project Guide: Dr. E.JANARTHANAN Department of ECE

OBJECTIVE The main objective of our project is : To design and implement a digital stethoscope using microcontroller to serve as a platform for potential computer aided diagnosis (CAD) applications for the detection of cardiac murmurs. It can Amplify, Play and Record heart signals in real time.

OBJECTIVE Capture a cardiac signal using a custom-built acoustic sensor and an analog-to-digital converter Output a real-time audio signal based on the sampled input using a digital-to-analog converter Record and playback captured signals using external Flash memory

OBJECTIVE Transmit real-time and recorded serial data via the USART for visualization and analysis To identify and remove the noise which pollutes the audio output signal during reading and writing of the Flash memory. Implementation of software FIR filters for diagnosing specific problem.

MOTIVATION To assist the physician to easily diagnose the problem from the waveform output Detect the cardiac murmurs significantly to identify the problem Recording the signal will be useful for remote monitoring of the patients It will be useful for inexperienced physicians.

HARDWARE SYSTEM Microcontroller ROM/RAM Signal conditioning SENSOR Speaker & interface LCD SCREEN KEYBOARD PC/MATLAB FLASH MEMORY

SYSTEM SOFTWARE HIGH LEVEL OVERVIEW

WORK DONE IN I REVIEW Compared the development boards MCB2100,MCB2140, AT91SAM9263-EK for final selection of board. Familiarized the keil software by simulating with simple programs MCB 2140 board is selected to carry out the project.

WORK COMPLETED TILL II REVIEW Studied features of A/D converter in LPC ADC,14 channels with 10 bit precision Studied special function registers associated with ADC. ADC REGISTERS: ADCR,ADGDR,ADDR,ADSTAT,ADINTEN Written program to convert any analog signal to digital signal in LPC2148

WORK DONE TILL II REVIEW ALGORITHM: Initialize ADC0/ADC1 and select any channel Configure the ADCR register and PINSEL register Manually tell ADC to start conversion Stop all conversion and start to read values Constantly read the conversion results from ADDR

SOURCE CODE #include //Header file for LPC 2148 int result=0;//variable declaration int main (void)// call main function { void init_adc(void);// call ADC initialisation while(1)//continue infinitely { result=adcRead();// get result from read function }

SOURCE CODE void init_adc(void) { PINSEL0 |= 0x ; // Enable pin corresponding to AD1.O (P0.6) AD1CR &= 0x ; // Clear All Bit Control AD1CR |= 0x ; // Select ADC = AIN8 // CLKDive => Pclk / (x +1) <4.5Mhz AD1CR |= 0x ; // ADC Clock = VBP (PCLK) / us AD1CR |= 0x ; //Burst (Continuous) = 1 = Conversion AD1CR &= 0xFFF1FFFF; // CLKS 11 cycles(10 bit resolution) AD1CR |= 0x ; // PDN = 1 = Active ADC Module AD1CR &= 0xFF3FFFFF; // TEST [1:0] = 00 = normal mode AD1CR &= 0xF7FFFFFF; // EDGE = 0 AD1STAT = 0x ; }

SOURCE CODE int adcRead(void)// READ sub routine { AD1CR= 0X00200D01;// Select channel 0 AD1CR |=0x ; //start AD conversion result = AD1GDR; // read data while((result& 0x )==0); // do till DONE bit is set result=(result>>6)&0x03FF; // bit 6:15 is 10 bit ADC VALUE return (result); }

RESULT

WORK TO BE DONE FOR PHASE I Design the acoustic sensor Generate PWM signal for audio playback Storing the signal in flash memory for later playback

REFERENCES Haibin Wang; Jian Chen; Yuliang Hu; Zhongwei Jiang; Choi Samjin;, "Heart Sound Measurement and Analysis System with Digital Stethoscope," Biomedical Engineering and Informatics, BMEI '09. 2nd International Conference on, vol., no., pp.1-5, Oct Ying-Wen Bai; Cheng-Hsiang Yeh;, "Design and implementation of a remote embedded DSP stethoscope with a method for judging heart murmur," Instrumentation and Measurement Technology Conference, I2MTC '09. IEEE, vol., no., pp , 5-7 May 2009 El-Bendary, N.; Al-Qaheri, H.; Zawbaa, H.M.; Hamed, M.; Hassanien, A.E.; Qiangfu Zhao; Abraham, A.;, "HSAS: Heart Sound Authentication System," Nature and Biologically Inspired Computing (NaBIC), 2010 Second World Congress on, vol., no., pp , Dec. 2010