论文标题
用于估计乳房机械参数的混合方法
An Hybrid Method for the Estimation of the Breast Mechanical Parameters
论文作者
论文摘要
有几种数值模型描述了用于解决复杂问题的实际现象。例如,由于手术模拟,准确的数值乳房模型可以为外科医生提供乳房的视觉信息。查找模型参数的过程需要基于医学成像技术或其他度量的数字输入。输入可以通过迭代方法(反弹性求解器)处理。这样的求解器非常健壮,并在所需的准确性程度内提供解决方案。但是,它们的计算复杂性是昂贵的。另一方面,基于机器学习的方法可实时提供输出。尽管可以达到高精度率,但这些方法并不能免于在所需的准确性程度之外生产解决方案。在现实生活中,非准确的解决方案可能会给患者带来并发症。 我们提出了一种混合参数估计方法,以利用上述方法的正面特征。我们的方法既保留了深度学习方法的实时性能,又保留了反弹性求解器的可靠性。我们的提案背后的基本推理是,深度学习方法(例如神经网络)可以在大多数情况下提供准确的结果,而他们只需要一个安全系统即可确保其可靠性。因此,我们建议使用多层神经网络(MNN)获取估计,而估计又由迭代求解器验证。如果MNN提供的估计不在所需的精度范围内,则求解器会完善估计,直到达到所需的准确性为止。根据我们的结果,我们可以得出结论,所提出的混合方法能够通过迭代求解器方法的鲁棒性来补充MNN的计算性能。
There are several numerical models that describe real phenomena being used to solve complex problems. For example, an accurate numerical breast model can provide assistance to surgeons with visual information of the breast as a result of a surgery simulation. The process of finding the model parameters requires numeric inputs, either based in medical imaging techniques, or other measures. Inputs can be processed by iterative methods (inverse elasticity solvers). Such solvers are highly robust and provide solutions within the required degree of accuracy. However, their computational complexity is costly. On the other hand, machine learning based approaches provide outputs in real-time. Although high accuracy rates can be achieved, these methods are not exempt from producing solutions outside the required degree of accuracy. In the context of real life situations, a non accurate solution might present complications to the patient. We present an hybrid parameter estimation method to take advantage of the positive features of each of the aforementioned approaches. Our method preserves both the real-time performance of deep-learning methods, and the reliability of inverse elasticity solvers. The underlying reasoning behind our proposal is the fact that deep-learning methods, such as neural networks, can provide accurate results in the majority of cases and they just need a fail-safe system to ensure its reliability. Hence, we propose using a Multilayer Neural Networks (MNN) to get an estimation which is in turn validated by a iterative solver. In case the MNN provides an estimation not within the required accuracy range, the solver refines the estimation until the required accuracy is achieved. Based on our results we can conclude that the presented hybrid method is able to complement the computational performance of MNNs with the robustness of iterative solver approaches.