睡眠中血压信号的关联维数计算

计算慢性阻塞性睡眠呼吸暂停综合症(OSAS)患者夜间血压的关联维数D2，并研究它和睡眠状态的联系。从替代数据检验结果和重构相空间轨迹看，血压信号具有一定的非线性确定性，但用GP算法计算D2时，D2值没有出现明显的饱和现象。统计并比较不同个体、不同睡眠状态下血压的D2值，在睡眠周期较完整时D2值较好地反映睡眠状态的变化：处于清醒、快速眼动期及浅睡时D2值较大，睡眠加深时D2值变小，表明相对D2值具有一定的应用价值。

Correlation dimension calculation of blood pressure during sleep

The blood pressure correlation dimension D2 of subjects with chronic obstructive sleep apnea syndrome during sleeping was calculated and the relationship between D2 and sleep stages were investigated in this work.According to the results of surrogate test and the re-constructed phase space track,the blood pressure was nonlinear determinate signal; but in calculation of D2 using GP arithmetic,the value of D2 was not saturated clearly. Take statistics and compare D2 of different subjects in different sleep stages,D2 reflect in some extent the change of sleep stages when sleep cycle was perfect:the value of D2 larger while being Wake,REM and low sleep,the value decreae while sleep became deeper. It is indicated that the relative value of D2 is potenvial of appvication.