Clinical study predicting prolonged postoperative ileus after laparoscopic colorectal cancer surgery with intelligent bowel sound auscultation system

Figure 7 Variable screening schematic diagram. A: Boruta analysis indicates that four variables—hypoproteinemia, recovery time of bowel sounds, number of bowel sounds, and operation time—were selected; B: The LASSO regression identified two variables, number of bowel sounds and operation time. FBS: Frequency of bowel sounds; CEA: Carcinoembryonic antigen; CA19-9: Carbohydrate antigen 19-9; BSVA: Bowel sound vibration amplitude; BMI: Body mass index; RTBS: Recovery time of bowel sounds; NBS: Number of bowel sounds.