RecruitingDevice studyThe Relationship Between Blood Flow Readings During Surgery and How Well the Graft Stays Open and How Patients Recover Afterward in Coronary Artery Bypass Graft SurgeryThe purpose of this study is to learn more about a tool called Transit-Time Flow Measurement (TTFM). TTFM uses sound waves during surgery to check how well blood is flowing through blood vessels. This helps doctors see if the blood flow is good during coronary artery bypass grafting (CABG), which is a type of heart surgery