b13 4 1000 60000 b13.dat 16 2/uV 12 0 -12 28441 0 AECG1 b13.dat 16 2/uV 12 0 8 -8242 0 AECG2 b13.dat 16 2/uV 12 0 -2 26839 0 AECG3 b13.dat 16 2/uV 12 0 10 19599 0 AECG4