Telemedicine Platform By: Neetika Malhotra Bharat Poddar

1. Telemedicine Platform By: Neetika Malhotra Bharat Poddar Sreenivas Rao BS TA: Kieran Levin

2. INTRODUCTION • The goal of this project: • Design a system to take the biometrics of a patient • Transfer measurements to a call center as an email attachment • Low cost device for remote assistance in areas with no medical facilities. • The biometric units that we have implemented are: • Electrocardiogram (ECG) • Blood Pressure/ Heart rate • Temperature

4. Our project consists of the following units: • BV513 PIC 32 micro controller • Hardware for all biometric measuring unit • Electrocardiogram (ECG) • Blood Pressure • Temperature • GSM unit for data transmission

5. Peripherals ECG Blood Pressure Temperature

6. Electrocardiograph (ECG) AD624

8. Problems faced and corrections: • AD624: • Due to high gain that we had set AD624 for, we were getting clipped output. • Changed the connections to get a gain of 200 instead of 1000. • 2. Used a band pass filter that did not filter properly. Switched to low pass filter with bandwidth of 150Hz. • The actual problem was with the source and not filter.

9. Blood Pressure Gain= 1+(200000/R6) ≅ 200 ; R6= 1000Ω

10. MPX2050 Differential voltage output of sensor directly proportional to differential pressure applied. Output voltage increases with increasing pressure applied to pressure side relative to vacuum side. Sensitivity: 0.8mV/kPa Calibration: Used sphygmomanometer to calibrate blood pressure. BP= Vout/1023*180 mmHg 180mmHg = 1.8V(from Sphygmomanometer)

11. Temperature Voltage set to 2.83V at room temperature.

12. We are using LM235 precision temperature sensor that can be calibrated. It is a 2-terminal Zener Breakdown voltage directly proportional to the absolute temperature at 10mV/0K. VoutT/VoutTo X TO = T Where VoutT = Output voltage at unknown temperature T VoutTo = Voltage at known temperature T0 T0 = Known Temperature T= Unknown temperature We are going to calibrate for 2.83V at 250C This means at 298.15 K the voltage will be 2.83V So if the body temperature is 310K or 98.40F, output voltage we will get: VoutT = 310/298.15 X 2.83 = 2.96V

13. BV 513

14. Development board for PIC32 Uses PIC32MX340F512H Micro SD card interface supporting up to 2GB 51 Input/Output pins 16 10-bit ADC channels Maximum 80MHz clock speed

15. Connector Layout • 16 ADC channels (JP3) 3.3V tolerance • General I/O pins (JP[4..6]) 5V tolerance • 2 UART ports

16. Functionalities Read in peripheral data through ADC channels. Calibrate data. Store in text files. Transmit files through UART to Telit GM862. Transmit data over GSM network.

17. Features Programmed using BASIC. Maximum sampling interval of 48μs achieved. Minimum sampling interval of 1.5μs achieved. Files saved as Text files on micro SD card. Programmed on host computer through USB.

18. ECG Data Stored on File

19. GSM MODULE – GM862 http://www.sparkfun.com/commerce/product_info.php?products_id=675

20. Turning on the GSM with the PIC Hold the ON/ OFF pin low for 1s. Voltage translation. Max current 0.1 mA.

21. Programming in GM 862 AT commands AT ( Line feed and Carriage Return) OK AT + CMGF =1 OK …

22. PIC – GSM programming Send AT commands as strings Send AT command, Receive AT command Send CR, Receive CR Receive response - OK (after 2-3 requests) Baud Rate Selected was 9600.

23. Baud Rate Selection Programmed in PIC: dim a=0 while a=0 out 1 “AT” a=inp(1,a$,200,13)// a=inp (port,string,time,wait for) out 1 13 a=inp(1,a$,200,13)// a=0 as CR is received with no char’s a=inp(1,a$,1000,13) // OK received when baud set. wait 300 // wait t => t in ms. wend

24. Problems faced Solution : AT # BND =3 AT#BND =3 OK AT+CREG? +CREG:0,1 // Network Registered *On Windows Hyper terminal 1. Network Registration : AT&T SIM card used AT#BND=1 // For US OK AT+CREG? +CREG: 0,2 // Finding network / registration AT+CREG? +CREG:0,3 // Registration failed

25. 2. PIC – GSM Handshaking Problems:Sent AT and CR. Received AT and CR respectively -> PIC sending commandsNo OK response from GSM. -> Baud not set / No communication from GSMSolution: Voltage conversion. (PIC : 5V, GSM : 2.8V)After implementing comparator circuit.Received OK. 3. PIC ports Problems : PIC module Hardware Problem.

26. Encryption of Data Encryption : F : function : chosen as rand (0, 3) F=0 : Add values F=1 : Multiply values F=2 : Divide values F=3 : Subtract values

27. Private Key: Issued by the Distributor to the user Key: The Private key is XOR’ed to the first value and this is the key further used. For rest of the values: a# = adc(3) // b3: ADC channel used. F= rand(0,3) select f case 0 a#=a#+key# case 1 a#=a#*key# case 2 a#=a#/key# case 3 a#=a#-key# default breakif f>-1 endselect

28. Ethical Considerations We need to take care about all our biometric units. During simulation we tested our design against all special cases to see the result. We need to have a high precision accuracy. Another area that we think is important is data encryption. Privacy of the user is very important and so we will do our best to come up with powerful encryption software. We need to take care about all voltages and power unit to avoid any shocks. Special care will be taken to insulate all wires and package the system carefully. The wattage and voltage readings for all peripherals will be clearly stated. A direction page will be provided to avoid any confusion and wrong data transfer. Special care will be taken to avoid any data loss.

29. Special Thanks to: • Professor Carney • Kieran Levin • Walley Smith • Dan Mast • Greg Cler