ECG Compression - ECG Acquisition and Automated Remote Processing - page 121

Appendix VI

The algorithm steps for 8-bit ASCII to 7-bit ASCII characters.

Appendix VII

Algorithms steps for sending formatted short messages to the GSM module
Serial communication settings for packet delivery MOD9001 GSM modem:
Baud 9,600, data bits 8, parity bit none, stop bit 1

1. open the compressed data file
2. put the characters in array x
3. convert characters in x into 7-bit ASCII characters in put in array y.
4. number of SMS to be transmitted, m = (y/159) ? 1;
5. get the destination phone number from GUI, and put in variable ph_no
6. form the data packet

j j ph no j

m þ 1

j end flag j

transmit header

7. deliver the packet to GSM modem
8. i = 1; j = 1; msg_sl = 1;
9. if y(i) = 0D h and y(i ? 1) = 0A h go to step 13
10. byte_frame (j) = y(i)
11. j = j+1; i = i ? 1;
12. go to step 15
13. byte_frame(j) = y(i) ? 06; byte_frame(j) = y(i) ? 06
14. j = j ? 2; i = i+2;
15. if j \ 159 go to step 9
16. form the data packet f transmit header j j ph no ; j byte frame j msg sl no :

end fla j jg and deliver to GSM modem using serial port
17. msg_sl = msg_sl ? 1;
18. if msg_sl = m go to step 20
19. go to step 9 for next packet formation
20. close the compressed file
21. stop

References

1. Jalaleddine SMS, Hutchens CG, Strattan RD, Coberly WA. ECG data compression

techniques: a unified approach. IEEE Trans Biomed Eng. 1990;37(4):329-43.
2. Schafer RW, Rabiner LR. A digital signal processing approach to interpolation. IEEE Proc.
1973;61:692-702.
3. Davisson LD. An approximate theory of prediction for data compression. IEEE Tran Inf
Theor. 1967;13(2):274-8.