Wireless esophageal pH capsule for patients with gastroesophageal reflux disease: A multicenter clinical study

Figure 4 Comparison of esophageal acid exposure measured during 24 h of simultaneous recordings in 45 patients with the conventional pH measurement system and the pH capsule (JSPH-1). A-D: There were no significant differences in pH parameters including the number of reflux episodes with a pH < 4 (P = 0.305), the number of episodes longer than 5 min (P = 0.058), the longest reflux time (P = 0.125), or the percentage of total time with a pH < 4 (P = 0.171) between the 2 systems; E: Overall median value of the total time with a pH < 4 was significantly shorter with the capsule system than with the catheter system (P = 0.014).