Research On Portable Reflectance Confocal Microscopy And Its Application For In Vivo Skin Detection

Laser scanning confocal microscopy has been widely used in life sciences,biomedicine,industrial testing,and other fields.Reflectance confocal microscopy is an important branch of confocal microscopy,which doesn’t need fluorescent labeling of the samples to be observed.It is particularly suitable for clinical fields such as skin and ophthalmology,where in vivo,real-time,noninvasive,and in situ examinations of observed objects are performed.It is also widely used in the field of industrial testing.In the field of clinical examination such as dermatology,it is necessary to have portable inspection equipment with high imaging resolution,which is convenient for the examiner to hold and operate with one hand.In addition,it is also possible to perform imaging examinations on difficult positions such as the nasal alar and underarm.Therefore,the development of portable reflectance confocal microscopy will provide a new and important tool for clinical examination,with important theoretical and practical significance.Based on the principle of reflectance confocal microscopy,this dissertation has realized the research of microscopic imaging technology which has the characteristics of in vivo,non-invasive,real-time and in situ.On the basis of in-depth analysis of confocal imaging theory and method,two key technologies which are image distortion correction and image brightness adaptive adjustment have been solved.What’s more,the localized portable confocal microscopy has been developed.Experimental research on the process of wounds repairment of mouse skin,and clinical application research on skin diseases have been carried out,and good application results have been achieved.The main research of this dissertation include:1.The theory of point scanning confocal imaging is introduced.And the illμmination point spread function,detection point spread function and effective point spread function of the system are emphatically analyzed.The theoretical derivation and qualitative analysis of imaging resolution,optical sectioning ability and imaging speckle of reflective confocal microscopy imaging system are discussed.The stray light elimination method based on the combination of PBS polarizing beam splitter prism and quarter-wave plate is proposed.2.The distortion mechanism of dual-mirror scanning and MEMS single-mirror scanning in the process of confocal microscopy imaging is analyzed.A twodimensional correction algorithm based on Hessian matrix is proposed for MEMS single-mirror scanning distortion.After image filtering and enhancement preprocessing,the centerline of raster sample image is extracted,feature processing and analysis are carried out,and pixel displacement correction is carried out.The two-dimensional distortion correction based on 7-degree polynomial interpolation of least square method is realized.3.Aiming at the problem that the brightness of images in different depths and positions of samples is different in the process of confocal microscopy imaging,an adaptive image brightness adjustment algorithm is proposed for skin imaging;The relationship between the light source control voltage and the output power of the objective lens is built,the image brightness evaluation index is selected,and the extreme brightness range and the moderate brightness range are divided.The adaptive image brightness adjustment based on linear compensation is realized.4.The prototype of portable reflectance confocal microscopy is designed and developed,and the overall scheme of the system is constructed.The design of optical unit,mechanical unit,electronic control unit and software unit are introduced respectively.The system integration,system imaging simulation and actual index test are realized.5.Using the portable reflectance confocal microscopy,the research on the process of wounds repairment of mouse skin and the clinical application of human skin diseases are carried out.In vivo imaging research is carried out in the evaluation of mouse skin wound healing,which proves the effectiveness of UC-MSC treatment on wound healing.What’s more,clinical trials of skin diseases have been completed in many hospitals,and good results have been achieved in skin diseases,skin radiation injuries and digestive tract diseases.So a new tool and examination scheme for clinical examination in the field of skin are provided.