The study population consists of 50 healthy volunteers who have not received upper gastrointestinal surgery and 100 patients treated with surgery more than one year ago (50 open and 50 minimally invasive). Chest wall movement will be measured using a 3D optical motion system and the investigators will establish if inertial measurement units placed strategically on the chest wall are able to quantify chest expansion and lung capacity. Data will be acquired during different breathing patterns and during use of an incentive spirometry. Pulmonary function tests will be undertaken in all patients and the investigators will also collect clinical data concerning health-related quality of life and other concomitant medical conditions. The target outcome of this study is to determine whether the 3D motion capture and wearable systems are reliable in the measurement of chest wall movement after surgical removal of esophagus and the validity and patient acceptability of wearable system, as well as the ability of distinguishing open and minimally invasive surgical approach. A tailored physiotherapy may be developed following this study in order to improve chest wall movement and objectively measure this using the wearable system. This can then be implemented in a clinical trial to provide the evidence base to for patient-tailored physiotherapy following major cancer surgery and to optimise the respiratory function.