2 within three thresholds for bilirubin absorbance ( 0 . 14 > 0 . 2 ( k 0 . 25 ) , the total , upright , supine , meal and postprandial period were analyzed with the parameters as follows , the percentage time of bilirubin absorbance threshold ( 0 . 14 , 0 . 20 0 . 25 ) , reflux frequency , long reflux frequency , longest reflux time , maximum , mean and median value of absorbance . 3 the simultaneous changes of gastric ph and bilirubin absorbance value were analyzed to describe the relationship between them 2计算0 . 14 、 0 . 20和0 . 25三个界值时胆红素吸收值( bilirubinabsorbance ， ba )界值的时间百分比的均值、标准差、中位数、第25 、 75 、 95位数；总、立位、卧位、餐时和餐后等各时段ba界值的时间百分比、反流频率、长时间反流频率、最长反流时间以及胆红素吸收值的最大值、平均值和中位值，以及ph 4的时间百分比，从而描述生理性dgr的发生特点。
