Patient connection (Question)

[ordonezt]

Hi! I have a question about the connection between the Front End and the patient.
In the "Front-End.sch" schematic there are two signals that I assume go to the PSoC board, "ECG+" and "ECG-", so only 2 signals are connected to the patient. But in figure 4.7 page 113 of "Thesis.pdf" there are 5 signals (ECGp_r, ECGp, ECGn, ECGn_r and ECGOffset. Can you please tell me how these lines connect to each other?
Regards