以電腦視覺進行斜頭症頭形及漏斗胸胸廓影像之特徵量測與分析

Abstract

本論文提出以電腦視覺方法對人體進行非侵入式、可量化之特徵量測與分析。借助熱可塑石膏條做為量測輔助工具，先將其加溫軟化後，置放於人體上接受矯正之部位，可以記錄此人體部位的外形輪廓。而後將固化後的熱可塑石膏條，經電腦影像掃描後轉換成電子圖檔，即可透過影像處理進行外形輪廓的量化量測與特徵分析。本論文以斜頭症頭形及漏斗胸胸廓為例，進行非侵入式、可量化之特徵量測與分析研究；對於斜頭症病徵的探討，本研究透過熱可塑石膏條擷取嬰兒頭形，再依據擷取的嬰兒頭形，發展一個類橢圓形狀的頭形模型，去衡量嬰兒頭形的對稱性。經由影像處理，計算出斜頸指標及頭形凹凸指數圖表，來量化與分析嬰兒頭形的對稱情形，及描述嬰兒頭形局部區域凸起或凹陷狀況。就衡量頭形的對稱性來說，斜頸指標是一個有用的工具。而頭形凹凸指數圖表則為描述頭形局部區域凸起或凹陷有利的工具。透過此方法，可以瞭解斜頭症頭形的異常狀況，做為進行頭形矯正的參考。對於漏斗胸病患，本研究亦透過熱可塑石膏條進行胸廓測量，並記錄漏斗胸病患胸骨凹陷處，經過Nuss矯正手術後的變化。研究中針對漏斗胸病患接受Nuss手術，在置入Nuss鋼板前後，進行胸廓變化的量化量測與分析。同時也針對漏斗胸病患在拔除Nuss鋼板後，進行胸廓變化的量化量測與分析。從研究中可觀測出病患置入Nuss鋼板後，胸廓會有明顯變化。這種現象也發生在拔除Nuss鋼板後，胸廓亦出現變化。本論文所提出以電腦視覺對人體進行非侵入式、可量化之特徵量測與分析之方法，方便快速、成本甚低、又不會引起副作用，對醫界應有相當參考價值。

This research proposed a non-invasive and quantifiable method which to measure and analyze the features of the human body by computer vision. The surface contour of the part of the human body which underwent corrective procedure was cast using the thermal plastic strip. The strip was soften in hot water and then positioned and taped to the part of the human body. After the strip solidified, it was removed and kept as a permanent record. The strip then was scanned to obtain a two-dimensional image which was proceeded quantitative measurement and feature analysis by image processing. The deformational plagiocephaly (DP) and pectus excavatum (PE) were examples in this research that proceeded quantitative measurement and feature analysis. For the deformational plagiocephaly, this research used above method to obtain infant’s head shape. Then rely on the shape to present ellipse-like fitting as an estimation method for detecting head shape symmetry of infant. By image processing, the plagiocephaly and concave/convex indices were developed to quantify and analyze the symmetry of infant’s head shape, and described head shape local condition of flattening or protruding. And it provides useful tools for clinical diagnosis, evaluation of deformational plagiocephaly and the natural development of positional plagiocephaly analysis. The head shape development data would be available before undertaking any treatment for patients before and after wearing corrective helmet. The same method also used in the measurement of anterior chest wall (ACW) in the pectus excavatum (PE) patients before and after insertion as well as removal of the Nuss bar. For the pectus excavatum, bar insertion after Nuss procedure caused significant increment in the height and width of ACW. However, bar removal lessened the correction effects in terms of the significant decrement in the height of ACW, but increment in the width of ACW. Nuss bar in situ had the important effect on the cosmetic of ACW. These immediate changes of the ACW contour gave us more data in consideration of the design of the bar shape at insertion. This research proposed a non-invasive and quantifiable method which to measure and analyze the features of the human body by computer vision, was convenient, rapid, low cost, and without a side effect. Experimental results revealed that the proposed method was a useful referral for surgery.