Over the last century, many devices have been developed with the intent of providing electrical stimulation. The main difficulty has always been to find a good method to "couple" or convey the electromagnetic energy of the source to the medium under stimulation. Often, neophytes are lead to believe that an electrical current can directly be transmitted through tissues or living organisms. Reality dictates otherwise. The main obstacle in transcutaneous stimulation, is the ability of the electrical currents, to penetrate and propagate through tissues without significant degradation or distortion of the nature of the signal transmitted. The reason for this difficulty lays in the complex impedance (change in resistance of the tissues with respect to frequency) presented by organic tissues to the source driving the signal. When dealing with direct current, what apparently seems straightforward can rapidly turn into a dangerous venture. Direct current above certain values dissociates the blood by electrolysis (decomposition of the blood into hydogen, oxygen and platelets), this condition creates bubbles which permeate through tissues and into joints (the bends). At the electrical current levels typically used by TENS units, irreparable damage can be caused to the cells. Although at first pain relief can be acheived, long term use can be dangerous (ref: Dr. Becker). It must however be remembered that TENS devices were developed more than 50 years ago. At that time very little was known about the effects of electrical impulses on cell tissue.

To adequately stimulate cells, frequencies ranging from 10 Hz to 35KHz are required. Additionally, to optimize results the signals transmitted must keep their integrity and be devoid of distortion while maintaining their harmonic content. MicroStimula MKII has been specifically designed to meet the transcutaneous propagation requirements, and to maximize the energy content available at the rise time of each pulse. Another important factor, which compounds the difficulty, is the "skin interface" effect commonly present in transcutaneous stimulations. Technical Applications has developed new techniques to improve the "skin interface", and allow a broader range of frequencies to pass through the skin, thereby increasing the dynamic range available to the tissues. This problem was solved by carefully analyzing the skin interface characteristics and matching the MicroStimula output to the needs of the cells, without disruption.