A new type of return electrode aims to prevent some of the common problems associated with such devices, including adhesive-related skin injuries or pad-site burns, and it also provides an additional benefit. “Most return electrodes don't have any type of cushioning, but the Mega Soft Universal Plus technology incorporates a flexible gel that helps with pressure reduction,” said Paul Borgmeier, PhD, PE, Director of Research & Development at Ethicon, Inc., in an interview with MD+DI.
In describing how the Mega Soft Universal Plus return electrode works, Borgmeier said it makes sense to take a look at how the traditional, smaller, sticky return electrodes function first. “These return electrodes need to be applied directly to the patient’s skin, and depending on the patient, you may need to do some surface preparation before you apply it,” he said. They work by using a generator to deliver energy, which flows through the patient and then back out through the return electrode into the generator.
“The Mega Soft technology works differently,” Borgmeier said. “Inside the Mega Soft Universal Plus technology is a conductive mesh, and the conductive mesh is connected to the generator with a cord.” This conductive mesh is covered by a nonconductive gel that not only helps with reducing pressure, but it also keeps the patient from ever touching the conductive mesh.
When the patient is placed on the Mega Soft Universal Plus return electrode (see below), the circuit is completed by a principle called capacitive coupling, and it is related to the high-frequency outputs associated with the generator. “Again, the big difference is that the patient doesn't need to be in direct contact with the return electrode to work,” Borgmeier said. In fact, drapes or linens can be placed between the patient and the electrode and the electrode will still work as designed, he noted.
“With our technology the patient acts like a conductive element and is in close proximity to the conductive mesh inside the return electrode, yet it doesn’t touch the skin,” Borgmeier said. “When the electrical current from the generator enters the patient, it causes an equal amount of current to leave the mesh, so that the charges are balanced. And that's called displacement current.”
The electrodes also provide greater patient safety because of their larger size, which reduces the current density, and current density is what can lead to tissue injury if the levels get too high, Borgmeier said.
“Another big benefit has to do with when you use a traditional return electrode, if it becomes partially detached during a procedure, the current density increases because there's a smaller area of the return electrode in contact with the patient,” he said. “But because the Mega Soft Universal Plus technology works differently, the patient is never in contact with the conductive layer inside the return electrode,” Borgmeier continued, saying that this helps reduce the chance of pad-site injuries at the patient return electrode interface.
Mega Soft Universal Plus electrodes can be used on any patients weighing from 0.35 kg, (i.e., the smallest of neonates), with no maximum restriction on weight, and they are indicated for any monopolar electrosurgery. They are currently commercially available in the United States and Europe.