Significance: Polyp size is important for selecting the surveillance interval or treatment policy. Nevertheless, it is challenging to accurately estimate the polyp size during endoscopy. An easy and cost-effective function to assist in polyp size estimation is required. Aim: To propose a virtual scale function for endoscopy and evaluate its performance and expected accuracy. Approach: An adaptive virtual scale behavior was demonstrated. The measurement error of the virtual scale along the distance between the tip of the endoscope and the object plane was evaluated using graph paper. The accuracy of polyp size estimation by an expert endoscopist was compared with the accuracy of the biopsy forceps method using phantom images. Results: The measurement errors of the virtual scale were ≤ 0.7 mm when the distance to the graph paper, which faced the tip of the endoscope, varied from 4 to 30 mm. The accuracy with the virtual scale was significantly higher than that obtained with biopsy forceps (5.3 ± 5.5 % versus 11.9 ± 9.4 % , P < 0.001). Conclusions: The virtual scale function, which operates in real-time without any additional device, can be used to estimate polyp sizes easily and accurately with endoscopy.

中文翻译：

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用于实时准确估计息肉大小的胃肠内窥镜虚拟尺度函数：初步研究

意义：息肉大小对于选择监测间隔或治疗策略很重要。然而，在内窥镜检查过程中准确估计息肉大小具有挑战性。需要一个简单且具有成本效益的功能来帮助估计息肉大小。目的：提出一种用于内窥镜检查的虚拟尺度函数并评估其性能和预期精度。方法：演示了自适应虚拟比例行为。使用方格纸评估沿着内窥镜尖端和物体平面之间距离的虚拟刻度的测量误差。由内窥镜专家估计息肉大小的准确性与使用幻影图像的活检钳方法的准确性进行了比较。结果：当距方格纸距离时，虚拟标尺的测量误差≤0.7 mm，面对内窥镜的尖端，从 4 到 30 毫米不等。虚拟刻度的准确度明显高于活检钳的准确度（5.3 ± 5.5 % 对 11.9 ± 9.4 %，P < 0.001）。结论：无需任何额外设备即可实时运行的虚拟尺度功能可用于通过内窥镜轻松准确地估计息肉大小。