* SPICE netlist
V1 N012 0 PULSE(0 8m 0 .025 .025 0 .2)
A1 N006 N006 0 0 0 0 N008 0 MODULATOR mark=50k space=0
V2 N011 N012 PULSE(0 4m .15 .03 .02 0 .22)
V3 N006 N011 PULSE(0 2m .05 .01 .005 0 .11)
V4 EMG+ N008 SINE(0 20m 60 0 0 0)
V5 EMG- 0 SINE(0 20m 60 0 0 0)
R1 N002 N005 100k
V6 VCC 0 5
V7 -VCC 0 -5
R2 EMG+ 0 10Meg
R3 EMG- 0 10Meg
R4 N001 EMG_RAW 10k
R5 IntoRect N001 150k
XU3 N002 EMG- EMG+ -VCC 0 EMG_RAW VCC N005 LT1168 ;pnba RG1)FB)In+)V-)REF)OUT)V+)RG2
XU4 0 N001 VCC -VCC IntoRect 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
R6 N003 IntoRect 6.8K
R7 N004 N003 6.8K
R8 N009 N004 3.4K
R9 N009 IntoRect 6.8K
R10 N010 N009 6.8K
D1 N007 N003 1N4148
D2 N004 N007 1N4148
XU1 0 N003 Vcc -Vcc N007 level1 Avol=1Meg GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
XU2 0 N009 Vcc -Vcc N010 level1 Avol=1Meg GBW=10Meg 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 4896 816
WIRE 400 -392 240 -392
WIRE 560 -392 480 -392
WIRE -1616 -344 -1680 -344
WIRE -752 -312 -800 -312
WIRE -1680 -296 -1680 -344
WIRE -1024 -296 -1040 -296
WIRE -832 -296 -1024 -296
WIRE -752 -296 -752 -312
WIRE -832 -280 -832 -296
WIRE -816 -280 -832 -280
WIRE -832 -264 -944 -264
WIRE 320 -264 320 -296
WIRE -944 -248 -944 -264
WIRE -832 -248 -832 -264
WIRE -816 -248 -832 -248
WIRE 112 -248 48 -248
WIRE 240 -248 240 -392
WIRE 240 -248 192 -248
WIRE 288 -248 240 -248
WIRE -656 -232 -688 -232
WIRE 560 -232 560 -392
WIRE 560 -232 352 -232
WIRE 1312 -232 1184 -232
WIRE 1696 -232 1392 -232
WIRE -816 -216 -832 -216
WIRE -656 -216 -656 -232
WIRE -576 -216 -656 -216
WIRE 288 -216 240 -216
WIRE -832 -168 -832 -216
WIRE -832 -168 -944 -168
WIRE -784 -168 -800 -168
WIRE -1856 -152 -1888 -152
WIRE -720 -152 -720 -168
WIRE -1024 -136 -1040 -136
WIRE -816 -136 -816 -184
WIRE -816 -136 -1024 -136
WIRE 1184 -136 1184 -232
WIRE 1312 -136 1184 -136
WIRE 1488 -136 1376 -136
WIRE -1680 -120 -1680 -216
WIRE -1680 -120 -1712 -120
WIRE -800 -120 -800 -168
WIRE 240 -120 240 -216
WIRE -1888 -88 -1888 -152
WIRE -1856 -88 -1888 -88
WIRE -2448 -24 -2448 -40
WIRE -1888 -24 -1888 -88
WIRE -1680 -24 -1888 -24
WIRE 864 -24 832 -24
WIRE 1024 -24 864 -24
WIRE 1072 -24 1024 -24
WIRE 1184 -24 1184 -136
WIRE 1184 -24 1152 -24
WIRE 1280 -24 1184 -24
WIRE -1680 8 -1680 -24
WIRE 1280 24 1280 -24
WIRE 1296 24 1280 24
WIRE 1488 40 1488 -136
WIRE 1488 40 1360 40
WIRE 1552 40 1488 40
WIRE 1696 40 1696 -232
WIRE 1696 40 1616 40
WIRE 1808 40 1696 40
WIRE 1968 40 1888 40
WIRE 1296 56 1248 56
WIRE 1248 88 1248 56
WIRE 2192 120 2032 120
WIRE 2352 120 2272 120
WIRE -1680 152 -1680 88
WIRE -2448 200 -2448 184
WIRE 1024 232 1024 -24
WIRE 1600 232 1024 232
WIRE 1968 232 1968 40
WIRE 1968 232 1680 232
WIRE 2032 232 2032 120
WIRE 2032 232 1968 232
WIRE 2144 232 2032 232
WIRE -1024 264 -1056 264
WIRE 2144 264 2144 232
WIRE 2224 264 2144 264
WIRE 2352 280 2352 120
WIRE 2352 280 2288 280
WIRE 2448 280 2352 280
WIRE -1680 296 -1680 232
WIRE -1056 296 -1056 264
WIRE 2224 296 2176 296
WIRE 2176 360 2176 296
WIRE -1680 408 -1680 376
WIRE -1056 408 -1056 376
FLAG -1680 408 0
FLAG -1056 408 0
FLAG -1616 -344 EMG+
IOPIN -16 -192 Out
FLAG -1024 264 EMG-
IOPIN 576 416 Out
FLAG -1040 -296 EMG+
IOPIN 560 -144 In
FLAG -1040 -136 EMG-
IOPIN 560 16 In
FLAG -2448 56 0
FLAG -2448 280 0
FLAG -2448 -40 VCC
FLAG -2448 184 -VCC
FLAG -800 -120 -VCC
FLAG -800 -312 VCC
FLAG -720 -152 0
FLAG -576 -216 EMG_RAW
IOPIN 1024 -64 Out
FLAG -1024 -216 0
FLAG -1024 -56 0
FLAG 48 -248 EMG_RAW
IOPIN 1648 -96 In
FLAG 240 -120 0
FLAG 320 -296 VCC
FLAG 320 -200 -VCC
FLAG 1248 88 0
FLAG 2176 360 0
FLAG 1328 8 Vcc
FLAG 2256 248 Vcc
FLAG 2256 312 -Vcc
FLAG 1328 72 -Vcc
FLAG 560 -232 IntoRect
FLAG 864 -24 IntoRect
SYMBOL voltage -1680 280 R0
SYMATTR InstName V1
SYMATTR Value PULSE(0 8m 0 .025 .025 0 .2)
SYMBOL modulate -1856 -152 R0
SYMATTR Value mark=50k space=0
SYMATTR InstName A1
SYMBOL voltage -1680 136 R0
SYMATTR InstName V2
SYMATTR Value PULSE(0 4m .15 .03 .02 0 .22)
SYMBOL voltage -1680 -8 R0
SYMATTR InstName V3
SYMATTR Value PULSE(0 2m .05 .01 .005 0 .11)
SYMBOL voltage -1680 -312 R0
SYMATTR InstName V4
SYMATTR Value SINE(0 20m 60 0 0 0)
SYMBOL voltage -1056 280 R0
SYMATTR InstName V5
SYMATTR Value SINE(0 20m 60 0 0 0)
SYMBOL res -960 -264 R0
SYMATTR InstName R1
SYMATTR Value 100k
SYMBOL voltage -2448 -40 R0
SYMATTR InstName V6
SYMATTR Value 5
SYMBOL voltage -2448 184 R0
SYMATTR InstName V7
SYMATTR Value -5
SYMBOL res -1040 -312 R0
SYMATTR Value 10Meg
SYMATTR InstName R2
SYMBOL res -1040 -152 R0
SYMATTR Value 10Meg
SYMATTR InstName R3
SYMBOL res 208 -264 R90
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 496 -408 R90
SYMATTR InstName R5
SYMATTR Value 150k
SYMBOL LT1168 -752 -232 R0
SYMATTR InstName U3
SYMBOL UniversalOpamp2 320 -232 R0
SYMATTR InstName U4
SYMBOL res 1168 -40 R90
SYMATTR InstName R6
SYMATTR Value 6.8K
SYMBOL res 1408 -248 R90
SYMATTR InstName R7
SYMATTR Value 6.8K
SYMBOL res 1904 24 R90
SYMATTR InstName R8
SYMATTR Value 3.4K
SYMBOL res 1696 216 R90
SYMATTR InstName R9
SYMATTR Value 6.8K
SYMBOL res 2288 104 R90
SYMATTR InstName R10
SYMATTR Value 6.8K
SYMBOL diode 1376 -152 R90
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode 1616 24 R90
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL OpAmps/UniversalOpAmp 1328 40 R0
SYMATTR InstName U1
SYMBOL OpAmps/UniversalOpAmp 2256 280 R0
SYMATTR InstName U2