Image Based Skin Analysis

by Ralph Hill - Internet Technology Researcher and Writerby Ralph Hill - Internet Technology Researcher and Writer

In a world where the quick fix and equally quicker answers to our appearance issues are demanded, it is no surprise that technologies are being constantly developed to satisfy that need. Skin analysis is one of those areas, but can the current technology available replace clinical knowledge and skill? We examine image based skin analysis systems and ask that question.

Any professional skin treatment practitioner knows the importance of a good skin analysis to determine what course of action to take when treating the skin, and this fundamental task has not gone unaffected by technology. We already have available professional analysis procedures and techniques supported with digital skin measuring tools that provide accurate data, and now there are visually based imaging tools that can help analyse the skin with the help of software. It is important that clients understand the complexities of their skin, are fully informed in their choice of treatment and how it will affect their appearance. Equally important is the need to demonstrate how a treatment is progressing, even when early results are not visible to the naked eye. This is where digital imaging and analysis devices can help. The scope of this article is to explain how these devices work, how accurate and useful they are, and how they are implemented in the professional skin care practice.

Too good to be true?

Unfortunately, many aestheticians and skin care professionals initially get the wrong perception of the ability of these devices. The concept of being able to proficiently analyse a client's skin by putting their face in a little booth, making a few mouse clicks and being provided with the treatment solution seems too good to be true. If only it was that simple. (Many marketers of these devices insist that it is, but unfortunately few are appropriately qualified or experienced to make those claims)

The concept of being able to proficiently analyse a clients skin by putting their face in a little booth, making a few mouse clicks and being provided with the treatment solutions seems too good to be true.The concept of being able to proficiently analyse a clients skin by putting their face in a little booth, making a few mouse clicks and being provided with the treatment solutions seems too good to be true.

Using digital imaging to assist skin analysis is not a new concept. In the late 1990s Japanese microscope manufacturer Scalar developed a great digital camera that was bundled with the rudementary skin analysis software, Skin-Xpert and sold under various brands worldwide. Some of you may remember the Skin Scope and Beauty Scope (A higher resolution version of this camera is still available today)

The main feature of this technology was the ability to look at the skin close-up, and compare what was seen with examples of different skin conditions to help diagnosis. 

Today we have a whole new breed of image based devices that employ a technique known as Fluorescence spectroscopy to tell us more about what is happening with our client's skin.

The technology

According to Wikipedia, Fluorescence spectroscopy is defined as:

A type of electromagnetic spectroscopy used for analyzing fluorescent spectra. It involves using a beam of light, usually ultraviolet light, that excites the electrons in molecules of certain compounds and causes them to emit light of a lower energy, typically, but not necessarily, visible light.  A complementary technique is absorption spectroscopy.

So what is going on with this skin?  An SIA view of the same face is shown belowSo what is going on with this skin? An SIA view of the same face is shown below

While all of this sounds a mouthful, in simple terms Fluorescence spectroscopy allows us to view the skin under different light conditions, that show us characteristics that we can't see with the naked eye.
Skin treatment therapists and Aestheticians already use this type of technology in its simplest form: black light skin scanners or woods lamps.
Fluorescence spectroscopy allows us to evaluate the physical and chemical properties of tissues by analysing the intensity and character of light emitted in the form of fluorescence. This technology has been utilized for the non-invasive detection and quantification of many deep conditions such as melanomas and differentiating between malign and benign skin tumors for many years, but because of high cost has until recently been confined to medical facilities with corresponding budgets.

The software has identified all of the pigmentation that falls in to a specific colour rangeThe software has identified all of the pigmentation that falls in to a specific colour rangeIn the medical field this imaging is known as Spectrophotometric Intracutaneous analysis (SIA). It must be pointed out that most of the devices available to the Aesthetics market are more rudimentary versions of what is used in medical practice, and this should be reflected in the cost.

How SIA works

The imaging devices use a number of light sources to capture a series of digital images to be analysed. Both Safe UV (around 420-460nm) and Flourescent light is used because of the different qualities each light source offers. This is known as multi-spectral imaging.

Some devices use polarising filters to reduce reflected light and show the skin surface in more detail.

The key features of using Fluorescence spectroscopy is the use of a image booth, specialised light sources and a high resolution digital cameraThe key features of using Fluorescence spectroscopy is the use of a image booth, specialised light sources and a high resolution digital camera

The real secret of gathering information that is useful to the skin treatment therapist, is the use of software or artificial inteligence to make sense of what is being seen.
To do this, the captured images are analysed by proprietory software to provide a quantitive analysis of what it can see.
The software compares what it can see against databased information to extract and display zones on the image that correspond to various known conditions and anomolies.

Safe UV light (400nm) from low power LEDs is used to illuminate the skin surfaceSafe UV light (400nm) from low power LEDs is used to illuminate the skin surfaceThese databases consist of a number of dermatological scales and statistical data from around the world. (Cosmetic and personal care giant Proctor & Gamble provided statistical data from over 3500 women around the globe for the first version of one particular software application).

As an example, if we were interested in the content of the oil flows of a client's skin, when the software analysed the image of the skin, it finds all the areas that correspond to the light signature of sebum and porphryns and displays them on the image. The intensity of the reflected light determines the amount of each of the items of interest.
Similarly, it can identify the varying degrees of photo damage not visible under normal lighting conditions. The software can quantify the amount of darker areas compared to the clear area to grade the severity of damage, identify and counts spots, grade skin eveness, grade wrinkles etc.

A typical "map"of blocked pores identified by the analysis softwareA typical "map"of blocked pores identified by the analysis softwareThe software also has the ability to image pores and wrinkles, and displays the wrinkles in a 3-D map to show depth and size. Of course the wrinkles are already visible with the naked (and magnified) eye, but seeing them as a 3 dimensional map is a remarkably detailed view. Pore quantity and size can also be calculated, along with overall skin surface evenness and texture.

The great thing about all of this is that you can provide fantastic before and after photos for your clients. If your treatments are successful and they are playing their part by doing their homework, then they will see the differences in a totally unique way. In addition to providing you with information to assist your analysis, one of the main features is the ability to link identified skin types and conditions with skin care products. 

Oil flows and porphyn prescence can be quantifiedOil flows and porphyn prescence can be quantified

Dependent on what prevelant skin conditions are diagnosed by the software, it can recommend a specific product from a skin care range to help correct the problem.
Of course to do this, you will have previously loaded all of the products you sell in the software database by type and recommended usage.

Below are the key features of SIA systems.

SIA measuring parameters

  • UV damage
  • Pore health assessment (presence of bacteria, excess sebum, pore inflammation
  • Skin tone variation
  • Wrinkle measurement and overall wrinkle score (%)

SIA features

  • Ability to divide face into zones for detailed analysis images 
  • Ability to produce repeatable high quality before & after images
  • Ability to effectively communicate skin concerns to clients with visual tools

Comprehensive interpetation of the data is visually impressiveComprehensive interpetation of the data is visually impressivePractical deployment of SIA

If you are thinking to yourself that this type of technology would greatly benefit the domestic retail (Department store) market, then you would be absolutely correct. If set up thoroughly and correctly, then little or no knowledge of the skin is really required, just a degree of training to talk the talk. This alarming reality was aptly demonstrated at a number of International trade shows I attended over the last year, where demonstrators where putting queues of eager people through the devices, pointing out the problems with their skins, and recommending product solutions to correct their maladies.

Unfortunately, what was being demonstrated was providing no better detail of what we can see and diagnose with black light and polarising magi lamps. No real analysis was being conducted per se, and along with the ever repeated key phrases Visual communication tool and Effective marketing tool, it was quite obvious what the intended use was. At one trade event in the US, a demonstrator was proudly pointing out that the operator did not have to be qualified with any knowledge of the skin, because the device would do all the hard work for them. Another compared their particular device to the skin expert you don't have to employ. The alarm bells of competance and integrity were sounding loudly by this time.

These experiences are not to say that the devices do not have a practical use in the skin treatment practice, but just an example of how this technology can be used (or misused) in the hands of individuals with less training than skin care professionals. (A number of leading cosmetic companies use SIA devices on cosmetics counters around the world)

SIA in the professional skin treatment practice

So where in the bigger picture of a professional skin consultation, will these devices fit in? In the course of a professional skin analysis, after we have taken the client's medical and lifestyle history, conducted a visual examination and noted areas of interest, the next usual step is to conduct reference measurements of lipid flows, hydration levels, melanin density and location, degree of vascularity, (erythema) and if appropriate, a pH test. 

SIA devices can provide some of this information for us, but not all. An example of this is hydration. (Or the amount of free water in the epidermis). The question of measuring lipid levels is also an issue.

In some software, the amount of lipid is calculated by light reflection and compared to a scale, however no actual physical measurement is taken. There is also questionable ability to accurately determine Fitzpatrick skin type as only the facial area is used to take measurements with no reference point of unexposed skin. (An aspect missed by many developers). Any professional skin treatment practitioner knows that every skin condition has a variety of causes and unique signatures. Because SIA software compares what it sees to only what it knows, it leaves room for error. This was exemplified by discussions with some users of the technology.

We asked a number of users of current SIA devices with medical and paramedical backgrounds for frank opinion on the usefulness of the technology as a professional diagnostic tool, and received the popular comment that it was limited due to the assumptive nature of the software and the lack of data presented. The common comparison was with conventional and much less expensive woods lamp devices, although the greater ability to distinguish between freckles and UV damage and the ease of taking excellent before/after photos was particullaly useful. (Although an expensive method of getting a good result). It was also reported that for professional skin analysis, it has not been uncommon to overrule the technological findings of SIA devices, because they do not fit the clinical findings. This may be due to the over simplification of the SIA analysis process to suit a more marketing oriented use. This would support the view of the primary aim being that of an aid for selling products and services, rather than significant clinical value.

Up to 8 specific spectrums of light are used in medical grade SIA devices. Compare this with just 2 from aesthetic grade devicesUp to 8 specific spectrums of light are used in medical grade SIA devices. Compare this with just 2 from aesthetic grade devicesAnd finally...

It is clear that the SIA Images and corresponding interpretation is only as good as the methodology used and software employed. This is where the major differences between aesthetic grade and the medical grade devices exists.

In medical grade devices, up to eight narrow-band spectrally filtered images of the skin across a light spectrum from 400 to 1000nm are employed, with complex algorithms in the software producing a wide range of data including melanin depth, (epidermal & dermal) collagen and haemoglobin content, and 'erythematous blush' with blood displacement. Devices marketed to the Aesthetics industry offer the user less data to interpret due to generally only two spectrally filtered images being analysed. This is sufficient for (as previously mentioned) visual communication and effective marketing, but the most useful feature for the skin treatment professional may be the producing of impressive before and after images to monitor client progress. 

Many practitioners believe there is no  substitute for a thourough clinical analysis with tools that provide relevant informationMany practitioners believe there is no substitute for a thourough clinical analysis with tools that provide relevant informationIt is interesting to note that these aesthetic grade devices are aften referred to as "complexion analysers" rather than skin condition analysers, and it is this title that should indicate our expectations of performance.

Professional skin counseling techniques and objective analysis still requires the practitioner to be knowledgeable about the skin and know what to look for and what questions to ask.
A thourough analysis consultation procedure using black light, polarised magnifying instruments and skin measuring devices will provide excellent data when diagnosing skin conditions, but will take at least an hour to perform.
There will always be fast track methods on offer to reduce this time, and skin analysing devices that utilise SIA and complex software have shown promise in identifying many parameters of skin health and condition. (Although arguably more useful to the unskilled practitioner).

At this early stage of development and relatively high cost, (compared to a black light device, a polarising magnifier and a digital epidermal measuring device) the question of justification remains, "Can current SIA devices replace clinical knowledge and skill, or provide enough detailed information required by the discerning skin treatment therapist of today?"

About the Author

Ralph Hill is the technology writer, illustrator and editor for Virtual Beauty Corporation. He has a background in science, electronics and electro-mechanical devices, but enjoys researching and writing on a myriad of skin care related topics including cosmetic chemistry and anatomy & physiology.




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