The choice of which electrodes one should use with an Infrex unit is a commonly asked question. Let's discuss it or watch our video.
Basically an electrode's intended purpose is to allow the even distribution of electrical current from the end of the cable to the skin. The electrodes ( 2-4 ) must be placed so the area where the pain is perceived is totally absorbed in the space between the electrodes.
However with the Infex + unit there is an additional concern one does not have with a traditional tens type unit. The issue is the greater amount of electricity coming from the Infrex+ unit versus a tens unit. 8,000+ pulses per second versus 150 pulses per second (rate) requires a larger disbursement area which means the surface area of an interferential electrode has to be larger than a tens unit. If not the concentration of the electrical charges in the smaller area will be uncomfortable for the patient.
Most tens units use an electrode that is 2" x 2" or 4 square inches of surface area touching the patient's skin. This is fine for a typical tens unit but not for the Infrex+. We suggest larger electrodes such as a 3" round ( 9+ sq. inches) or a 1.75" x 3.75" electrode (7+ sq. inches) as these electrodes have the larger surface area and the pain area can be covered without too high an intensity underneath the electrodes.
Because the tens function of the Infrex + unit is also stronger than most tens units, 350 microseconds of pulse width versus most tens units being 250 - 300 microseconds, we recommend the larger electrodes for the tens application using the Infrex +. To prolong the life of the electrodes please visit our article on caring for reusable electrodes.