Table 2.

The advantages and disadvantages of three methods of providing ES

Methods	Advantages	Disadvantages
Direct coupling [59]	Easy operation	Insufficient biocompatibility of the electrode, contact with the medium lead to temperature rise, pH changes, and the generation of harmful byproducts
Capacitive coupling [64]	More biologically safe	High voltage between the electrodes, longer treatment time
Inductive coupling [62]	Mimic the natural potential transfer in the human body, does not directly touch cells	Tumorigenesis in unexpected area, taking time and resource consumption