Non-contact monitoring of the depth temperature profile for medical laser scanning technologies

Medical treatments such as high-intensity focused ultrasound, hyperthermic laser lipolysis or radiofrequency are employed as a minimally invasive alternatives for targeted tissue therapies. The increased temperature of the tissue triggers various thermal effects and leads to an unavoidable damage. As targeted tissues are generally located below the surface, various approaches are utilized to prevent skin layers from overheating and irreparable thermal damages. These procedures are often accompanied by cooling systems and protective layers accounting for a non-trivial detection of the subsurface temperature peak. Here, we show a temperature peak estimation method based on infrared thermography recording of the surface temperature evolution coupled with a thermal-diffusion-based model and a time-dependent data matching algorithm. The performance of the newly developed method was further showcased by employing hyperthermic laser lipolysis on an ex-vivo porcine fat tissue. Deviations of the estimated peak temperature remained below 1 °C, as validated by simultaneous measurement of depth temperature field within the tissue. Reconstruction of the depth profile shows a good reproducibility of the real temperature distribution with a small deviation of the peak temperature position. A thermal camera in combination with the time-dependent matching bears the scope for non-contact monitoring of the depth temperature profile as fast as 30 s. The latest demand for miniaturization of thermal cameras provides the possibility to embed the model in portable thermal scanners or medical laser technologies for improving safety and efficiency.

Complications of Cryolipolysis: Paradoxical Adipose Hyperplasia (PAH) and Beyond

Background Cryolipolysis is a fairly popular procedure performed in North America, Europe, and many other countries. Although it is considered a rather safe procedure, there are underreported side effects such as paradoxical adipose hyperplasia (PAH), contour irregularities, skin and soft tissue atrophy, and asymmetries. Our knowledge regarding the prevalence and treatment of such complications is limited. Objectives We hereby report a case series of 5 patients treated for various complications of cryolipolysis, including PAH, that persisted for more than 12 months after their last treatment. Methods Five patients with various complications of cryolipolysis (4 patients with PAH and 1 with atrophy and indentations) presented in our private office between 2015 and 2018. Three of the 4 patients with PAH were treated at other facilities with ultrasonic liposuction, laser lipolysis, and radiofrequency skin tightening devices respectively. The fourth patient developed PAH after liposuction at another facility. The fifth patient developed several areas of indentations and atrophy and received mesotherapy and lymphatic massages at another facility. All 5 patients were subsequently treated in our office by means of a customized approach specific to their underlying complications. Results Near-normal results were achieved in all 5 patients. None of our patients showed any recurrences of their initial complication for which they were treated. All 5 patients were extremely satisfied with their results. Conclusions Cryolipolysis, just like any other form of lipolysis, has certain specific adverse effects associated with it, including but not limited to PAH. Complications of cryolipolysis must be individually recognized and treated accordingly. Level of Evidence: 4