Image analysis and processing methods in verifying the correctness of performing low-invasive esthetic medical procedures

BACKGROUND Efficacy and safety of various treatments using fractional laser or radiofrequency depend, to a large extent, on precise movement of equipment head across the patient's skin. In addition, they both depend on uniform distribution of emitted pulses throughout the treated skin area. The pulses should be closely adjacent but they should not overlap. Pulse overlapping results in amplification of irradiation dose and carries the danger of unwanted effects. METHODS Images obtained in infrared mode (Flir SC5200 thermovision camera equipped with photon detector) were entered into Matlab environment. Thermal changes in the skin were forced by CO₂RE laser. Proposed image analysis and processing methods enable automatic recognition of CO₂RE laser sites of action, making possible to assess the correctness of performed cosmetic procedures. RESULTS 80 images were acquired and analyzed. Regions of interest (ROI) for the entire treatment field were determined automatically. In accordance with the proposed algorithm, laser-irradiated Li areas (ROI) were determined for the treatment area. On this basis, error values were calculated and expressed as percentage of area not covered by any irradiation dose (δo) and as percentage area which received double dose (δz). The respective values for the analyzed images were δo=17.87±10.5% and δz=1.97±1.5%, respectively. CONCLUSIONS The presented method of verifying the correctness of performing low-invasive esthetic medical (cosmetic) procedures has proved itself numerous times in practice. Advantages of the method include: automatic determination of coverage error values δo and δz, non-invasive, sterile and remote-controlled thermovisual mode of measurements, and possibility of assessing dynamics of patient's skin temperature changes.