摘要或動機

醫學上的植皮手術成功率受皮膚厚度影響，皮膚愈薄癒合速度愈快，其中以取皮厚度介於0.05mm 到0.1mm 為佳。在實驗量測時，需要經過一連串繁複的薄皮標本製作，再放到光學顯微鏡下測量，這種厚度測量方式不但耗時，又因嚴重損毀皮膚而不精確。由於使用螺旋測微器做接觸式測量會有形變的問題，因此我們想做間接接觸式的測量，所以採用氣體為媒介，做非破壞性檢測膜厚，這對於在皮膚上的施力遠小於螺旋測微器或是接觸式膜厚計。我們設計一套三頭連管線，使用空氣為媒介，儀器運作原理為在管線一端針頭非常靠近被測物時，所流出的氣體會受到被測物阻礙產生反壓使管線內的壓力上升，導致連通於另一管路的氣泡指示計壓出氣泡，當氣泡為最大氣泡時（半球形）視為達到平衡狀態。實驗時先用已知厚度且不變形的蓋玻片來當作被測物，此時可以算出針尖至蓋玻片的實際距離做為參考值。在量測軟性薄膜時，設計上採用兩側雙針頭靠近軟性被測薄膜兩側以達到氣流氣泡平衡，這時使用螺旋測微器讀取兩針尖距離，減去已知參考值的兩倍距離，即可測出未形變的軟物質厚度。本研究開發一套能測量軟性薄膜的厚度裝置，尤其在皮膚厚度測定上，不但不會直接接觸標本造成損毀，並且能夠快速地測量出厚度值，此為本儀器的最大特色。The thickness of skin graft has deterministic influences on the success of graft surgery. Experimental measurements of skin graft thickness involve complicated specimen preparation processes followed by optical microscopic examination, which are time-consuming and may incur inaccuracy due to possible damage. Here we propose a novel method using air as the media to avoid direct contact of the measured object. The physical operation relies on the following principles: When the tip of a needle connecting to a catheter system is placed close to the object to be measured, the air pumped forward from the catheter system becomes impeded by the object. The resulting backflow pressure opposing the air flow causes
an increase in air pressure within the catheter and inflates the bubble connected at the other end. Balance at maximal surface tension is attained when the bubble reaches its maximum volume in hemispherical shape. In practice, a two-needle design was used, each approaching simultaneously from each side of the object. A micrometer was then used to read the distance between the two needle tips, from which the film thickness was derived, subtracting the thickness of the air layer pre-calibrated using cover glass with known thickness. The system implemented was capable of measuring thickness on soft thin films with an accuracy of ± 0.001mm. In addition to rapid measurements with high accuracy, since the pressure exerted on the skin graft is much less than in conventional calipers requiring direct contact, our method has the unique non-distorted and non-destructive advantages.