近紅外光擴散光學造影(near infrared diffuse optical imaging, NIR DOI)，其機制為藉由不同生理組織對NIR特定波長的光吸收、散射特性差異，以此區分生理組織組成狀況；再以數個等間隔高度之量測切面建立斷層造影像。基於先前應用於乳癌檢測之俯臥式擴散光學斷層造影機台，設計彈性光通道以適應不同仿體幾何外型，並建立該斷面幾何輪廓資訊，使光學係數分布的重建影像具有實際仿體輪廓之幾何資訊。 基於頻域式光學量測技術，分別使用同步多頻率與單頻電源率驅動光源，即20、30、40 MHz之混和弦波與個別單一頻率弦波，比較兩種光源驅動方式效果。透過光電倍增管擷取仿體表面逸出之光強度所轉成的電訊號，再透過電訊號頻譜分析提取各檢測點之幅值與相位資訊，最後將幅值與相位藉由擴散光學造影軟體系統DopIm重建光學係數分布影像。 本研究以仿乳房光學係數之80 mm圓柱仿體進行同步多頻率與單頻率電源驅動光源進行實驗，兩種光源驅動的重建影像差異。實驗結果中同步多頻率量測之重建影像能檢測置入物位置並分辨其大小，但相同幅值下多次單頻率較同步多頻率量測優異。而多頻率重建因具有較多光資訊，預期其重建結果優於單頻率重建結果，而由CNR值量化影像重建結果，多頻率重建CNR值介於單頻率重建CNR值，雖有部分多頻率重建優於單頻率重建但幅度不大。另以斷面長軸110 mm、短軸90 mm半橢球仿體以80 MHz單頻率電源驅動光源量測，以彈性光通道估算量測斷面之輪廓，建立輪廓有限元素網格，於影像重建中使用。並藉由量測不同高度之切面建立擬(pseudo)三維影像。 ;Near infrared diffuse optical tomography (NIR DOI) is used to differentiate the composition of tissue by the difference in absorption and scattering characteristics of different physiological tissues for specific wavelengths of NIR. Based on the previous application of a prone diffusion optical tomography machine for breast cancer detection, a flexible optical channel was designed to adjust the detection range and estimate the contour information to make the reconstructed image of optical coefficient distribution with the geometric information of the actual contour of the mimic body, thus improving the resolution of the reconstructed image. Based on frequency-domain optical measurement technology, the results of synchronized multi-frequency and single-frequency reconstruction are compared. The optical measurement is driven by two types of light sources: 20, 30, 40 MHz mixed sine waves and single frequency sine waves. A photomultiplier tube is used to collect surface light information and convert it into electrical signals. The amplitude and phase of each detection point are detected by signal processing. The optical coefficient distribution image is reconstructed by DopIm, a diffuse optical imaging software system. In this study using an 80 mm cylindrical phantom with breast-like optical coefficients for synchronized multi-frequency and single-frequency light source driving measurement, to compare the difference between single-frequency and multi-frequency reconstructions of the two light sources. The 110-90 mm half-ellipsoid was measured with 80 MHz single frequency and the geometric properties of the slices were measured by the flexible optical channel. A try was also made to create pseudo 3D images by measuring different height slices.
