A Study Of Developing A Computer-aided Designing System For Augmentation Mammaplasty

A fluent, plump, beautiful body curve is a characteristic of normal developed woman, and a well-rounded breast is one of the most important structures of the feminine physique. However, some women lost their beautiful curve and attractiveness because of congenital or postnatal reason. With the rapid development of national economy and improvement of life standard, people pay more and more attention to pursuing esthetical figure, and the demand for augmentation mammaplasty increases gradually.At present, the plastic surgeon helps those patients, whose breast is thin and flat or asymmetry, by augmentation mammaplasty with silicone or saline implants generally due to its security, validity as well as the feasibility. However, there are more and more patients who are not satisfied with the operation outcome. They complain that it is not so perfect as what they've imagined or the surgeon's said. That can be ascribed to the lack of visual aid to fulfill sufficient communication preoperatively. Therefore, the method that can provide scientific guidance and simulates the effectiveness of augmentation mammaplasty is needed clinically.With the fast development of computer and photoelectron techniques, much attention has been paid to the computer-aided optic projection measurement that can reflect the 3-D shape characteristic of the measured subject objectively. The measurement technique also makes some advancement in breast reconstructive surgery by estimating breast aesthetics and guiding reconstructive operation based on 3-D shape measurement. But few research about simulation of augmentation mammaplasty using 3-D image reconstruction technique has been reported.Using the virtual reference plane technique in the computer aided projecting fringe measurement , the computer aided projecting fringe measurement system (CAPFMS) has been developed in the previous study. It can precisely, rapidly, conveniently, untouchedly and highly automatically collect 3-D shape data of plastic model's breasts and real ones, display and storage the collected data with 3-D digital images, and measure the plane or spatial distance between two random points, the surface area and the volume of breast as well.Based on the data provided by the CAPFMS, we have reconstructed the 3-D image of the breast surface and implant, simulated the reality of the postoperative breast, developed a computer-aided designing system for augmentation mammaplasty (AM-CADS).In this paper, the researches are concentrated in the following aspect:Firstly, the basic principle and method of 3-D reconstruction of the breast surface has been addressed. A quadratic filtration value method based on symmetrical pels is put forward to reconstruct breast surface. The powerful rendering function has been used to add material to breast surface and areolar surface, the same as the backdrop and lamp-house. The fast algorithm of the 3-D reconstruction of breasts based on non-uniform rational B-spline (NURBS) has been proposed. Applying the figure standard of OpenGL, we have also simulated the reality of breasts.Secondly, the parameterization design method of mammary prosthesis has been developed in order to realize its 3-D reconstruction and the result simulation of augmentation mammaplasty. Applying the software of graphics tools, AutoCAD and OpenGL respectively, we have simulated the postoperative breast figure successfully.Thirdly, on the data collected by the CAPFMS, we have proposed some methods to pretreat it. We analyzed the reason for each kind of system error, and proposed the corresponding processing methods. After analyzing the principle of multi-aperture splicing, to overcome the insufficiency of this method, we have inferred three dimensional orthogonal splicing curve match law based on the space characteristic. Using the automatic cutting method on the stripe chart, we eliminates the high noise in the three dimensional data.Fourthly, according to the speciality of the data collected by the CAPFMS, we have selected Microsoft Access as the database system which has realized the access of huge quantitive data. At the same time, data processing also involves the memories and the demonstration of the information about patients and surgery, as well as the image and the demonstration preoperatively and postoperatively and so on. As the supplement of database dynamic storage, the serial access function has also realized the documents access of the collected data.Based on our research work, we can draw the following conclusion: l)The AM-CADS provides a visualized method for augmentation mammaplasty. 2) The CAPFMS has many advantages such as noncontact, high speed, easily realization and high precision, etc. It is a practical technique of 3-D shape measurement. 3) Surface reconstruction based on NURBS is not only facilitory to quick reconstruction, but also beneficial to express, store and show. So that it is a kind of feasible 3-D reconstruction technique. 4) There are advantages and disadvantages in developing application software with AutoCAD and OpenGL each other.