In electrotherapy, what does the bipolar technique entail?

In electrotherapy, what does the bipolar technique entail?

• A. Electrodes of unequal size that create higher current density under the smaller electrode, leaving one active.
• B. Electrodes of equal size with essentially equal current density under them; both electrodes are active.
• C. One electrode active and one grounded electrode.
• D. A single electrode delivering current to tissue.

Answer: (B)

Two electrodes of equal size placed on the treatment area produce a current with essentially equal density under each pad, so both electrodes are active. This is the essence of the bipolar technique: the current flows directly between the two active electrodes through the tissue between them, creating a focused field without a distant return path. The equal sizes matter because electrode size determines current density; when sizes are equal, the density under each electrode is the same, ensuring neither electrode dominates and both contribute to the therapeutic effect. If electrodes were unequal in size, the smaller one would carry higher current density, making the setup unbalanced and not characteristic of the bipolar approach. Using one electrode with grounding or a single electrode delivering current describes monopolar or unipolar configurations, where only one electrode is actively delivering current and the other serves as a distant return.

Two electrodes of equal size placed on the treatment area produce a current with essentially equal density under each pad, so both electrodes are active. This is the essence of the bipolar technique: the current flows directly between the two active electrodes through the tissue between them, creating a focused field without a distant return path. The equal sizes matter because electrode size determines current density; when sizes are equal, the density under each electrode is the same, ensuring neither electrode dominates and both contribute to the therapeutic effect. If electrodes were unequal in size, the smaller one would carry higher current density, making the setup unbalanced and not characteristic of the bipolar approach. Using one electrode with grounding or a single electrode delivering current describes monopolar or unipolar configurations, where only one electrode is actively delivering current and the other serves as a distant return.