软结肠镜的临床应用在肠道疾病的诊断及治疗上是一大进步，不但能诊断大肠及末端回肠疾病，更重要的是可以用来治疗一些经保守治疗无效的下消化道内科疾病以及一些外科疾病，如肠息肉、肠扭转等需外科手术才能治愈的疾病可用软结肠镜治疗。我们对1987年7月至2001年8月采用软结肠镜诊治的低位肠梗阻、乙状结肠扭转、假性结肠梗阻、下消化道出血、良性肠狭窄及肠道息肉等9 051例需外科处理的疾病加以探讨，以提高软结肠镜在治疗外科疾病中的安全性及疗效。
The purpose of this study is to investigate the change of the whole brain event-related potentials(P300) in normal brain aging based on N-back cognitive tasks. The P300 of 15 normal young people and 10 normal old people were evaluated based on N-back cognitive tasks and analyzed. The results showed that the P300 latency of old people was longer in whole brain than young people, and amplitude was increased in the frontal-central region, while significantly increased in the pre-frontal region in the same load cognitive tasks. With the cognitive task load increasing, the amplitude of old people in high-load task was higher in the whole brain than that in low-load task, mainly in in the frontal region, but the difference was not statistically significant. The latency in the high-load task was shorter in the frontal-central region of right brain than the low-load task, and the difference was statistically significant. Thus, P300 showed that the normal brain aging process is mainly reflected in the pre-frontal region, and the high-load cognitive task could better reflect the change of brain function compared with the low-load cognitive task. The finding is of revelatory meaning for diagnosis of early dementia in patients.