1. Department of Veterans Affairs Medical Center, Ann Arbor , MI , USA
2. Department of Internal Medicine, University of Michigan, Ann Arbor , MI , USA
3. Department of Biomedical Engineering, University of Michigan, Ann Arbor , MI , USA
4. Stryker Corporation, Kalamazoo , MI , USA
5. Department of Mechanical Engineering, University of Michigan, Ann Arbor , MI , USA
6. Department of Anesthesiology, University of Michigan, Ann Arbor , MI , USA