TENS units

Transcutaneous Electrical Nerve Stimulation

Over the last century, many devices have been developed with the intent of providing electrical stimulation for living organic tissues. The main difficulty has always been to find a good method to "couple" or convey the electromagnetic energy of the source to the tissues under stimulation. Often, neophytes are lead to believe that an electrical current can directly be transmitted through tissues or living organisms. In reality the major difficulty presented to transcutaneous stimulation, is the ability of any apparatus to deliver the desired electrical currents and penetrate living tissues. In general there is significant degradation of the electrical signals, which are distorted by the changes in the complex resistance (impedance) presented by the skin interface to the driving circuit.
When dealing with direct current, what initially seems as a simple solution can rapidly turn into a dangerous venture. Direct current above certain current levels decompose the blood by electrolysis creating bubbles which permeate through tissues. TENS units, typically use electrical high current levels by (by cell standards, 60 mA) and can cause irreparable damage to the cells. Initially some pain relief is achieved, however long term use can be dangerous (ref: Dr. Becker). It must be remembered that the first TENS devices were developed more than 50 years ago, and at that time very little was known about the effects of electrical impulses on tissue cells.

Transcutaneous Electrical Cellular Stimulation

The MicroStimula MKII, a safer more effective alternative
To adequately stimulate cells, frequencies ranging from 10 Hz to 35KHz are required. At these frequencies, it is necessary to match the impedance of the skin interface to optimize the quality of the signals transmitted, and minimize the distortion while maintaining a rich harmonic content. The
MicroStimula MKII has been specifically designed to meet these transcutaneous propagation requirements, and to maximize the energy content available at the rise time of each pulse. As mentioned above, another important factor compounding 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 carfully anayzing the skin interface charateristics and matching the MicroStimula MKII output to the needs of the cells, without causing disruption or damage.

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