Kress comes on board after a two-year search. She was CFO of a Cisco Systems unit.
Ahuja will stay to aid the successor search.
Use of technology can lead to a range of problems for the body, such as tablet neck, eye strain, lumbar weakness, and health problems associated with prolonged sitting and inactivity.
Fernandez was CFO before being promoted to chief operating officer. CFO Patrick McGuiness is set to depart Nov. 27.
Hohauser, who been serving as a consultant at Exclusive Media, is a former CFO at Summit.
Thomas succeeds Joe Kaeser, who has been promoted to CEO. Thomas was the finance chief for industrial products.