* SPICE netlist
V1 N008 0 PULSE(0 8m 0 .025 .025 0 .2)
A1 N005 N005 0 0 0 0 N006 0 MODULATOR mark=50k space=0
V2 N007 N008 PULSE(0 4m .15 .03 .02 0 .22)
V3 N005 N007 PULSE(0 2m .05 .01 .005 0 .11)
V4 EMG+ N006 SINE(0 20m 60 0 0 0)
V5 EMG- 0 SINE(0 20m 60 0 0 0)
R1 N003 N004 100k
V6 VCC 0 5
V7 -VCC 0 -5
R2 EMG+ 0 10Meg
R3 EMG- 0 10Meg
R4 N001 EMG_RAW 10k
R5 N002 N001 150k
XU3 N003 EMG- EMG+ -VCC 0 EMG_RAW VCC N004 LT1168 ;pnba RG1)FB)In+)V-)REF)OUT)V+)RG2
XU4 0 N001 VCC -VCC N002 level2 Avol=1Meg GBW=10Meg Slew=10Meg Ilimit=25m Rail=0 Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
.tran 1

* LTspice schematic (.asc)
Version 4
SHEET 1 3008 816
WIRE 1344 -392 1184 -392
WIRE 1504 -392 1424 -392
WIRE -672 -344 -736 -344
WIRE 192 -312 144 -312
WIRE -736 -296 -736 -344
WIRE -80 -296 -96 -296
WIRE 112 -296 -80 -296
WIRE 192 -296 192 -312
WIRE 112 -280 112 -296
WIRE 128 -280 112 -280
WIRE 112 -264 0 -264
WIRE 1264 -264 1264 -296
WIRE 0 -248 0 -264
WIRE 112 -248 112 -264
WIRE 128 -248 112 -248
WIRE 1056 -248 992 -248
WIRE 1184 -248 1184 -392
WIRE 1184 -248 1136 -248
WIRE 1232 -248 1184 -248
WIRE 288 -232 256 -232
WIRE 1504 -232 1504 -392
WIRE 1504 -232 1296 -232
WIRE 128 -216 112 -216
WIRE 288 -216 288 -232
WIRE 368 -216 288 -216
WIRE 1232 -216 1184 -216
WIRE 112 -168 112 -216
WIRE 112 -168 0 -168
WIRE 160 -168 144 -168
WIRE -912 -152 -944 -152
WIRE 224 -152 224 -168
WIRE -80 -136 -96 -136
WIRE 128 -136 128 -184
WIRE 128 -136 -80 -136
WIRE -736 -120 -736 -216
WIRE -736 -120 -768 -120
WIRE 144 -120 144 -168
WIRE 1184 -120 1184 -216
WIRE -944 -88 -944 -152
WIRE -912 -88 -944 -88
WIRE -1504 -24 -1504 -40
WIRE -944 -24 -944 -88
WIRE -736 -24 -944 -24
WIRE -736 8 -736 -24
WIRE -736 152 -736 88
WIRE -1504 200 -1504 184
WIRE -80 264 -112 264
WIRE -736 296 -736 232
WIRE -112 296 -112 264
WIRE -736 408 -736 376
WIRE -112 408 -112 376
FLAG -736 408 0
FLAG -112 408 0
FLAG -672 -344 EMG+
IOPIN -16 -192 Out
FLAG -80 264 EMG-
IOPIN 576 416 Out
FLAG -96 -296 EMG+
IOPIN 560 -144 In
FLAG -96 -136 EMG-
IOPIN 560 16 In
FLAG -1504 56 0
FLAG -1504 280 0
FLAG -1504 -40 VCC
FLAG -1504 184 -VCC
FLAG 144 -120 -VCC
FLAG 144 -312 VCC
FLAG 224 -152 0
FLAG 368 -216 EMG_RAW
IOPIN 1024 -64 Out
FLAG -80 -216 0
FLAG -80 -56 0
FLAG 992 -248 EMG_RAW
IOPIN 1648 -96 In
FLAG 1184 -120 0
FLAG 1264 -296 VCC
FLAG 1264 -200 -VCC
SYMBOL voltage -736 280 R0
SYMATTR InstName V1
SYMATTR Value PULSE(0 8m 0 .025 .025 0 .2)
SYMBOL SpecialFunctions\\modulate -912 -152 R0
SYMATTR Value mark=50k space=0
SYMATTR InstName A1
SYMBOL voltage -736 136 R0
SYMATTR InstName V2
SYMATTR Value PULSE(0 4m .15 .03 .02 0 .22)
SYMBOL voltage -736 -8 R0
SYMATTR InstName V3
SYMATTR Value PULSE(0 2m .05 .01 .005 0 .11)
SYMBOL voltage -736 -312 R0
SYMATTR InstName V4
SYMATTR Value SINE(0 20m 60 0 0 0)
SYMBOL voltage -112 280 R0
SYMATTR InstName V5
SYMATTR Value SINE(0 20m 60 0 0 0)
SYMBOL res -16 -264 R0
SYMATTR InstName R1
SYMATTR Value 100k
SYMBOL voltage -1504 -40 R0
SYMATTR InstName V6
SYMATTR Value 5
SYMBOL voltage -1504 184 R0
SYMATTR InstName V7
SYMATTR Value -5
SYMBOL res -96 -312 R0
SYMATTR Value 10Meg
SYMATTR InstName R2
SYMBOL res -96 -152 R0
SYMATTR Value 10Meg
SYMATTR InstName R3
SYMBOL res 1152 -264 R90
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 1440 -408 R90
SYMATTR InstName R5
SYMATTR Value 150k
SYMBOL OpAmps\\LT1168 192 -232 R0
SYMATTR InstName U3
SYMBOL OpAmps\\UniversalOpamp2 1264 -232 R0
SYMATTR InstName U4