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In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance). I have been able get th...
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opamp
#4: Post edited
by
tilly
·
2023-08-26T07:47:06Z (9 months ago)
- In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance).
- I have been able get the thermal noise data for only dry electrodes of different materials. Dry electrodes are the same electrodes in this case but placed without any Gel. At 100kOhms impedance the white noise is the same as any 100KOhms resistor but the different electrodes have different corner frequency and the exact curve of the 1/f noise on the graph is different as well. (Noise density per square root Hz on the y-axis and frequency on the x-axis, like in op-amp data sheets)
- Will/can the corner frequency change if the source impedance is reduced to <5kOhms using a gel or the corner frequency and curve will be the same as 100kOhms data except that the noise density for white and pink noise will be reduced to a <5kOhms resistor level?
https://pubs.acs.org/cms/10.1021/acsomega.2c00282/asset/images/medium/ao2c00282_0008.gif The electrode-skin interface forms a galvanic half-cell (Geddes, 1972)
- In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance).
- I have been able get the thermal noise data for only dry electrodes of different materials. Dry electrodes are the same electrodes in this case but placed without any Gel. At 100kOhms impedance the white noise is the same as any 100KOhms resistor but the different electrodes have different corner frequency and the exact curve of the 1/f noise on the graph is different as well. (Noise density per square root Hz on the y-axis and frequency on the x-axis, like in op-amp data sheets)
- Will/can the corner frequency change if the source impedance is reduced to <5kOhms using a gel or the corner frequency and curve will be the same as 100kOhms data except that the noise density for white and pink noise will be reduced to a <5kOhms resistor level?
- https://pubs.acs.org/cms/10.1021/acsomega.2c00282/asset/images/medium/ao2c00282_0008.gif The electrode-skin interface forms a galvanic half-cell (Geddes, 1972) It is significantly more difficult (and perhaps much more expensive) to collect the noise data at low impedance.
#3: Post edited
by
tilly
·
2023-08-26T07:33:18Z (9 months ago)
- In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance).
I have been able get the thermal noise data for only dry electrodes of different materials. Dry electrodes are the same electrodes in this case but placed without any Gel. At 100kOhms impedance the white noise is the same as any 100KOhms resistor but the different electrodes have different corner frequency and the exact curve of the 1/f noise on the graph is different as well. (Noise density per square root Hz on the y-axis and frequency on the x-axis, like in op-amps data sheets)- Will/can the corner frequency change if the source impedance is reduced to <5kOhms using a gel or the corner frequency and curve will be the same as 100kOhms data except that the noise density for white and pink noise will be reduced to a <5kOhms resistor level?
- https://pubs.acs.org/cms/10.1021/acsomega.2c00282/asset/images/medium/ao2c00282_0008.gif The electrode-skin interface forms a galvanic half-cell (Geddes, 1972)
- In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance).
- I have been able get the thermal noise data for only dry electrodes of different materials. Dry electrodes are the same electrodes in this case but placed without any Gel. At 100kOhms impedance the white noise is the same as any 100KOhms resistor but the different electrodes have different corner frequency and the exact curve of the 1/f noise on the graph is different as well. (Noise density per square root Hz on the y-axis and frequency on the x-axis, like in op-amp data sheets)
- Will/can the corner frequency change if the source impedance is reduced to <5kOhms using a gel or the corner frequency and curve will be the same as 100kOhms data except that the noise density for white and pink noise will be reduced to a <5kOhms resistor level?
- https://pubs.acs.org/cms/10.1021/acsomega.2c00282/asset/images/medium/ao2c00282_0008.gif The electrode-skin interface forms a galvanic half-cell (Geddes, 1972)
#2: Post edited
by
tilly
·
2023-08-26T05:26:19Z (9 months ago)
- In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance).
- I have been able get the thermal noise data for only dry electrodes of different materials. Dry electrodes are the same electrodes in this case but placed without any Gel. At 100kOhms impedance the white noise is the same as any 100KOhms resistor but the different electrodes have different corner frequency and the exact curve of the 1/f noise on the graph is different as well. (Noise density per square root Hz on the y-axis and frequency on the x-axis, like in op-amps data sheets)
Will/can the corner frequency change if the source impedance is reduced to <5kOhms using a gel or the corner frequency and curve will be the same as 100kOhms data except that the noise density for white and pink noise will be reduced to a <5kOhms resistor level?
- In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance).
- I have been able get the thermal noise data for only dry electrodes of different materials. Dry electrodes are the same electrodes in this case but placed without any Gel. At 100kOhms impedance the white noise is the same as any 100KOhms resistor but the different electrodes have different corner frequency and the exact curve of the 1/f noise on the graph is different as well. (Noise density per square root Hz on the y-axis and frequency on the x-axis, like in op-amps data sheets)
- Will/can the corner frequency change if the source impedance is reduced to <5kOhms using a gel or the corner frequency and curve will be the same as 100kOhms data except that the noise density for white and pink noise will be reduced to a <5kOhms resistor level?
- https://pubs.acs.org/cms/10.1021/acsomega.2c00282/asset/images/medium/ao2c00282_0008.gif The electrode-skin interface forms a galvanic half-cell (Geddes, 1972)
#1: Initial revision
by
tilly
·
2023-08-26T05:00:18Z (9 months ago)
Can the corner frequency of thermal noise change with change in source impedance?
In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance). I have been able get the thermal noise data for only dry electrodes of different materials. Dry electrodes are the same electrodes in this case but placed without any Gel. At 100kOhms impedance the white noise is the same as any 100KOhms resistor but the different electrodes have different corner frequency and the exact curve of the 1/f noise on the graph is different as well. (Noise density per square root Hz on the y-axis and frequency on the x-axis, like in op-amps data sheets) Will/can the corner frequency change if the source impedance is reduced to <5kOhms using a gel or the corner frequency and curve will be the same as 100kOhms data except that the noise density for white and pink noise will be reduced to a <5kOhms resistor level?