Multiple right leg drives on one arm (EMG)

[darkdurrent]

I am developing a compact active EMG sensor. The PCB will be together packaged with the stainless steel electrodes. There will be 3 electrodes on each sensor (In+, In-, REF). REF elecrode will be driven with RLD circuit to improve CMRR and will be placed between In+ and In- electrodes.

When the project finished I will be use multiple EMG sensors on one arm.

Sensors will be placed on to the flexor and extensor muscles in the arm, can I use multiple RLD cirtuits on one arm like this manner? Are these RLD circuits will make the output signals more noisy or distorted as they fight each other instead of improving CMRR?

Please see the schematic to understand the problem mor clearly.

 

[betwixt]

Re: Multiple right led drives on one arm (EMG)

I'm no expert in this so forgive my question - where does "right led" drives come into this?

If the intention is just to take differential measurements about a common (REF) electrode, I don't see any problem in using one common across all sensors and reading In+ and In- for each sensor individually.

Brian.

 

[darkdurrent]

Sorry, I typed it wrong. My concirns is about "Right Leg Drive" not "Right Led Drive"
Right leg drive circuits are using in ECG applications commonly but it can be used any biosignal measurement applications.

https://en.wikipedia.org/wiki/Driven_right_leg_circuit

 

[betwixt]

Thanks for the correction - I had visions of multicolored flashing people!

Brian.