MONITORING TEMPERATURE INDUCED PHASE CHANGES IN SUBCUTANEOUS FATTY TISSUE USING AN ASTIGMATISM CORRECTED DYNAMIC NEEDLE PROBE

Cryolipolysis has become a popular non-invasive method of reducing excess fat by cooling. However, the results vary as metabolism, gender and diet may affect the freezing point of human subcutaneous fat. To increase the success for all patients, it is essential to better understand the process of cryolipolysis in vivo. Therefore, we have developed a side-facing needle probe with an outer diameter of 390 lam achieving a lateral resolution of 10 lam at a working distance of 1.5 mm. To obtain a spatially resolved visualization of the immediate processes involve in cryolipolysis, cross-sectional images was obtained by moving the needle probe back and forth in a transparent catheter. At the tip, the transparent catheter was equipped with a lancet for smoothly penetrating through the skin. By a rigorous design including optical wave simulation and by a careful combination of different materials astigmatic aberrations were avoided. Ex vivo measurements on subcutaneous porcine fat were performed to confirm, that imaging with the needle probe is a suitable method for investigating phase changes.