Department of Bioengineering, Joint Graduate Program between University of Texas at Arlington and University of Texas Southwestern Medical Center, University of Texas at Arlington, Arlington, Texas 76019, USA
Opt Lett. 2010 Feb 1;35(3):429-31. doi: 10.1364/OL.35.000429.
Diffuse optical tomography endures poor depth localization, since its sensitivity decreases severely with increased depth. In this study, we demonstrate a depth compensation algorithm (DCA), which optimally counterbalances the decay nature of light propagation in tissue so as to accurately localize absorbers in deep tissue. The novelty of DCA is to directly modify the sensitivity matrix, rather than the penalty term of regularization. DCA is based on maximum singular values (MSVs) of layered measurement sensitivities; these MSVs are inversely utilized to create a balancing weight matrix for compensating the measurement sensitivity in increased depth. Both computer simulations and laboratory experiments were performed to validate DCA. These results demonstrate that one (or two) 3-cm-deep absorber(s) can be accurately located in both lateral plane and depth within the laboratorial position errors.
扩散光学断层成像在深度定位方面存在局限性，因为随着深度的增加，其灵敏度会严重下降。在本研究中，我们展示了一种深度补偿算法 (DCA)，该算法可优化地平衡组织中光传播的衰减特性，从而准确地定位深层组织中的吸收体。DCA 的新颖之处在于直接修改灵敏度矩阵，而不是正则化项的惩罚项。DCA 基于分层测量灵敏度的最大奇异值 (MSVs)；这些 MSVs 被反用来创建一个平衡权重矩阵，以补偿增加深度的测量灵敏度。计算机模拟和实验室实验均验证了 DCA 的有效性。这些结果表明，在实验室位置误差范围内，可以在横向平面和深度内准确定位一个（或两个）3 厘米深的吸收体。
