question about e-stim neg/pos polarity hvpc wound healing

When using hvpc for wound healing, the negative electrode is placed near the wound and the positive distally. Does the machine then need to be set to a negative current? What if it is set to positive. Does the current chosen then come out of the matching electrode and flow to the other electrode? When the wound had reached the proliferative phase we were instructed to place the positive electrode near the wound and to switch the machine to positive, are positively charged ions then released from the positive electrode and flow to the other one.