Department of Anesthesiology;
Qianfo Mountain Hospital of Shandong University;
Jinan;
China.;
Department of Clinical Medicine;
Shandong University;
Jinan;
China;
Department of Orthopedics;
Qilu Hospital of Shandong Uni- versity;
Jinan;
China;
Stroke; Volume; Variations; Heart-Lung; Sternotomy; Monitoring; Functional; Hemodynamic; Cardiac; Surgery;