b81 4 1000 60000 b81.dat 16 2/uV 12 0 9 -29945 0 AECG1 b81.dat 16 2/uV 12 0 -34 -31313 0 AECG2 b81.dat 16 2/uV 12 0 -23 22263 0 AECG3 b81.dat 16 2/uV 12 0 18 29072 0 AECG4