The Infrex Plus is the most powerful portable interferential unit available today due to the AC adaptor for unlimited power supply.
Historically the problem with any portable interferential unit has been what type battery system is capable of a draw down of 8,000+ pulses per second ( rate or frequency). Simply stated that means the machine is going off and on at least 8,000 times each second. Many patients would go to a clinic or hospital for an interferential treatment because there were no viable options to having a unit to use when needed unless one purchased a clinical unit costing $4,000 - $15,000 per interferential machine. A single treatment could easily cost $100 or more and patients had to guess when they would need a treatment.
For years companies made what were called "portable interferential units" powered by a 9 volt or 4 AAA batteries. These units literally would last for less time than it took to walk to the cashier window in the clinic before the batteries had been totally exhausted. The demand for the energy interferential generates overwhelmed the battery technology available. If one wanted a unit to last for one typical clinical treatment ( 20 minutes) then the battery system would be so large the batteries needed would fit in a wheelbarrow. That removes the "portability" factor and would exacerbate most chronic pain situations (:)!!
One recent change has been in the progress of new and better batteries which last longer. The circuitry for electrical muscle stimulator devices, tens electrical stimulators, etc. has improved to be more energy efficient. Wave forms away from the traditional sine wave to the balanced biphasic square wave have improved electrotherapy devices.
The one big change for the Infrex Plus that has made the unit so effective in providing pain relief during treatment and extended carryover pain relief was the addition of the AC adaptor. With the AC adaptor the electrical energy supply is literally the grid you draw from. In the U.S. it is unlimited. Most chronic pain patients have accessability to electrical outlets and can gain pain relief when needed.
Also the new batteries, as well as the mixing of the electricity in the Infrex unit, have given the rechargeable battery system an extended life of 80 minutes of treatment time. In almost all cases that is sufficient energy for at least 2 separate interferential treatments wherever the patient is. It is intended to be a portable electronic first aid kit until the patient can get to an electrical outlet. Any patient traveling, in a public area, on an athletic field etc. can now treat using only the rechargeable battery system as the sole power source.