Table with <th> elements needed

Hallo,

the Vaadin table component adds at least 2 tables: header table and body table. Inspecting the element with Firebug it is visible that to element is used. Our application is tested with a screen reader and therefore an -Element is needed.
One recommendation was something like: "add an unvisible header row with element in the table with the datat items. ".

Any idea how to implement it ?