Carl, I have several questions about the circuit design. Where are the power supply decoupling capacitors for the ICs? What's your analysis for patient isolation? This looks like a 3-lead ECG; why are you AC-coupling the Right Arm and the Left arm?

@NickAlexeev I have not used any decoupling capacitors in this design? Is that a mistake? If so, what would they do to my circuit? I don't quite understand what you mean with: What's your analysis for patient isolation. The patient and amplifier are isolated. The amplifier is powered through two 9 V batteries and nothing is connected to building ground or the power lines. The right arm and left arm are AC-coupled to remove the half-cell DC battery associated with the lead electrodes. The highpass filter does also to some degree remove baseline drift caused by movement artifacts - but not that well.

(1) Not having decoupling capacitors is an error. (2) The battery powered circuit with wireless communication is an analysis of patient isolation. It sounds reasonable. (3) Only 2-lead ECG is AC-coupled. 3-lead id DC coupled. DC offset is removed from electrolytic effect will be present on both electrodes, so it will be canceled (subtracted) by the InAmp. The residual DC offset is removed downstream of the InAmp DC offset correction loop around the InAmp, or an analog high- or band-pass filter, or a DSP high- or band-pass filter.

@NickAlexeev Please post an answer to this question. You have peaked my interest, but writing this in the comment section is not the proper way I feel. Please explain what the addition of decoupling capacitors would do to the circuit.

Carl‭ It's standard practice to always put a 100nF cap close to the supply pin on every IC on the board (unless the IC datasheet comes with specific recommendations). Particularly so on 2 layer boards since you'll have much worse EMC characteristics without a ground plane.