Some notes on insulated probes

One of the things that interests both electrologists and their clientele are the types of probes being used and what their applications are. There are also some technical considerations for the use of different probe types.

In the attached picture, I have set up four .005" diameter insulated probes. They are from left to right: Ballet SS F5I, ProTec F5IBL (Blend), ProTec F5ITH (Thermolysis), and a Sterex F5I.

As the length of insulation affects the area and amount of energy that will be released into the tissues, there will be variations in insulation length along the probe. Of primary interest to the electrologist, in regards to insulation length, is what it does to the shape and size of the heat pattern during epilation.

The blue tic marks beside each probe shows the stopping point of the insulation along the length of each probe. As can be seen from the photograph, the Ballet probe has the longest uninsulated length while the Sterex has the shortest.


What does this mean in terms of usefulness? This is dependent on several physical factors:

  1. The shorter the length of uninsulated probe, the higher the resistance at the point of contact with the surrounding tissues. This translates into two distinct situations in regards to current flow: A) a slightly higher setting will be required to achieve the same current flow in the blend modality (for the galvanic element) for the shorter uninsulated probel lengths. B)Due to the higher resistance, at the higher settings more heat will be generated as the higher voltage drop from the increase of resistance wil result in a higher wattage of heat dissipation into a smaller area.

  2. The longer uninsulated probe lengths (UPL for expediency) will give a larger heating pattern than will the shorter uninsulated probe lengths. This is true for both galvanic and high frequency* energy. This allows the electrologist the opportunity to keep the heating pattern deeper into the skin layer, reducing the discomfort and making the treatment more comfortable for the client. The disadvantage with the shorter UPL’s is that they require a much higher degree of precision with the probe placement within the hair follicle in order to properly destroy the regenerative tissues within the follicle.

*One of the things that allows the effective use of high frequency to perform electrical epilation of hair is that, in order to be an efficent radiator of radio waves, the conducting element needs to equal the length of travel for 1/4 wavelength of the applied signal. For 12.56 MHz this would require a probe to be approximately 6 meters in length. However, we are not in the radio transmission business, but only concerned with transferring a small amount of electromagnetic energy into a small area of living tissue, causing thermocoagulation. For this, direct electrical connection is required to transfer this energy as less than 50% of the total energy sent to the probe is actually transferred to the tissues by both conduction and tip effect, the balance is reflected back to the source (the epilator) as standing waves along the probe cord.

Relative merits of the individual probe types from my observations:

In regards to the two probe types with the shortest UPL’s, (Sterex F5I and ProTec F5ITH): I have found these probes extremely useful when having to epilate large amounts of small diameter, shallow, accelerated vellus and small, shallow early anagen hairs. The disadvantage of these probes is that with their smaller heat patterns, they quickly become less effective and probe placement, during insertion, requires a much higher degree of accuracy in order to properly treat thick, deeper hairs. This is however, one of the theoretical “answers” to the difficulty of treating deep, thick hairs in moist, soft skin. Their primary usefulness seems to be their effectiveness in treating small, shallow hairs and limiting the amount of heat reaching the outer skin levels with the thermolysis modality.

The probes with the longer UPL’s are right at home with the blend modality. As they have longer lengths of direct electrical conductivity, they will release D.C. electricity more efficently over their lengths, distributing lye production over a larger area, although still a pear-shaped heating pattern. When the thermolysis element is applied, it also will give a larger heating pattern. Both of these effects still have the advantage of taking place deeper in the skin, increasing client comfort and minimizing damage to the outer skin layers when used with proper power application.

The last thing to note in all of this. Both the Ballet and Protec probes come to a sharp point via an elliptical curve. The Sterex has basically a much shorter, conical point. This characteristic also has an effect on the heating pattern. Of the 4 probes shown, the Sterex will generate the smallest heating pattern from top to bottom during power application. Again, this tends to be somewhat less than ideal for threating thicker, deeper hairs with longer papillae and a longer distance from the matrix to the bulge.

Anyway, I hope that some find this interesting and useful.

Hi Joanie,
Can you try sending the photos again? For some reason they did not go through.

Hi Lisa,

I had the picture on here as an attachment. However, as necessity is the mother of invention, or maybe even discovery, I just learned how to insert it in the body of the text.

Thank you for the learning opportunity! lol

Joanie <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />

Lisa, did you click on the word ‘attachment’ in the header of Joanie’s first post? I saw the pictures just fine yesterday and thanks goes to you Joanie for posting this.