Lee, Po-Chih2021-09-242021-09-242019-06https://hdl.handle.net/11299/224658University of Minnesota Ph.D. dissertation. June 2019. Major: Mechanical Engineering. Advisor: Arthur Erdman. 1 computer file (PDF); xiv, 194 pages.Spine deformity problems are common among different age cohorts. Progressive deformities of the spine deform the rib cage and cause complications, like cardiopulmonary disorders, back pain or mortality. A severe spine deformity has a negative influence on patients’ pulmonary function, because the limited thoracic cavity restricts the lungs from fully expanding. To evaluate spine patients’ respiratory function, doctors may use pulmonary function tests or CT scans to measure the lung volume. Since the former highly rely on patients’ understanding of the test instructions, the test results might be inaccurate when the instructions are not followed properly. The latter are often criticized for the high-dose radiation, and frequent exposure to CT scans adds risk to patients. In this study, the thoracic volume serves as an alternative way to follow up spine patients’ lung volume, and a simulation method to reconstruct the rib cage and measure the thoracic volume using biplanar X-rays is proposed. The semi-automatic software is designed based on this simulation method. Usability testing is conducted to evaluate the performance of the developed software. Also, a comparison of the thoracic volume measurements between my method and other existing methods is made. Two case studies are carried out to show the thoracic volume measured by the developed software can be a surrogate for the prediction of the lung function in spine patients. One case study is to monitor the thoracic volume variation during the growing rod surgical treatments in pediatric scoliosis patients, and the benefit of the growing rod surgery is discussed. The other is to correlate the parameters obtained from pulmonary function tests with the thoracic volume in adult scoliosis patients having different treatments during their adolescence. With the developed software, two quantitative studies are performed via virtual spine patients with osteoporotic or Scheuermann’s kyphosis vertebral wedging deformities. The influence of the wedging location and numbers on thoracic volume changes is explored. A replicable simulation workflow to create virtual spine patients is proposed, and its application in future clinical settings is also discussed.enPulmonary functionSimulationSpine deformityThoracic volumeUsability testingVirtual patientsThesis or Dissertation