Do not put the treatment room tower on the floor.
It is likely to be damaged from cleaning activities; it could easily get wet from spills or mopping and it will pick up lots of dirt and dust. The tower needs to be close to a power supply and allow access in and out for various cables. For example if you position under the chair you will need to run monitor cables and USB inputs under the floor to the tower.
The preferred location is in a cabinet behind the chair. That assumes rear delivery and cabinets with access to in wall or in floor channels to run the cables.