In early 2002, Ebert was diagnosed with papillary thyroid cancer. In February, surgeons at Northwestern Memorial Hospital successfully removed the cancer with clean margins. He later underwent surgery in 2003 for cancer in his salivary gland, and in December of that year, underwent a four-week follow-up course of radiation to his salivary glands, which altered his voice slightly. Ebert continued to be a dedicated critic of film, not missing a single opening while undergoing treatment. The cancer would eventually lead Ebert to be left in a wheelchair and unable to speak after having the total of three surgeries. Later on, experts created a translator that allowed Ebert to speak whatever he typed. He called his machine "Sir Olivier," because he thought its voice sounded like actor Laurence Olivier.