作者嘗試設計一套數位化的影像分析系統，提供震波碎石機操作者客觀的評估輔助工具，以避免腸氣、呼吸、骨骼等因素干擾影像品質而影響操作者的判斷。我們利用個人電腦連接到碎石機，擷取尿路結石影像後加以數位化分析，並立即在線上將分析結果回報操作者，以協助判斷是否已達到適當的震波數量。 先前已有實驗證實，尿路結石在X-光之下的影像強度(IDD, image density difference)，和其本身厚度成正相關。因此只要監測結石IDD的變化，就能知道結石瓦解的程度。在我們的實驗中發現，IDD隨著結石的破裂而降低。當影像強度的曲線趨於平緩，表示結石已完全粉碎或不再破裂。 藉著此一裝置，本系統可應用於臨床碎石治療，減少不必要的震波，從而使患者接受治療的不適降到最低，節省時間與醫療資源。我們的實驗結果顯示，經由數位影像的輔助，最多可以減少53%的震波而不影響治療效果，的確有發展的價值。

Extracorporeal shock wave lithotripsy (ESWL) is one of the most important modalities in modern treatment of uroilithiasis. In this study, we designed a digital image analysis system that serves as an objective evaluation aid during ESWL procedure. Because the image quality is often interfered with by bowel contents, respiration, bone shadow and other factors, this system helps the operators to judge the end-point of ESWL treatment more accurately. A personal computer is connected to the lithotripter, Results of analysis can be readily read on the monitor of personal computer. The results of ESWL are on-line evaluated for optimal quantity of shock wave treatment. Our experiments showed the correlation between stone fragmentation speed and the slope of image density difference (IDD) curve. By monitoring the change of the IDD, we can evaluate the degree of stone fragmentation. When the IDD curve becomes flat, the stone is either completely broken or resistant to the shock waves. By applying this design in our in vitro experiment, we have found digital image analysis a useful aid of ESWL that helps to estimate optimal amount of shock waves and to decrease the unnecessary appliance of shock waves. According to our studies, we may decrease shock wave number by as much as 53% without affecting the effect of ESWL treatment.