A patient interface module, PIM, holder, for attaching a PIM device having a cable to a rail in a medical environment, the PIM holder comprising: a holster having an open end sized to receive a PIM device and having a cable opening extending from the open end on a side adjacent the open end to a side opposite the open end; and a clamping device sized and configured to attach the holster to a rail, the clamping device comprising: a stationary jaw secured to the holster; and a moving jaw disposed adjacent the stationary jaw, the stationary jaw and moving jaw forming an opening that receives the rail in a lateral direction and forming a passage therebetween to capture the rail; and an actuator pivotable between an open position and a closed position to displace the moving jaw to open and close the clamping device; wherein the actuator includes a handle and a plurality of lever arms; wherein the handle is configured to be actuated to open the clamping device in order to attach or remove the PIM holder from the rail; wherein each of the plurality of lever arms comprises a pivot hole and a sliding slot, the pivot hole being located to correspond with a pivot hole in the stationary jaw and the sliding slot being located to correspond with a displacement passage through the moving jaw; wherein a pivot pin extends through the pivot holes in the stationary jaw and the pivot holes of the actuator and acts as an axle to define a pivot axis allowing the actuator to pivot about the pivot pin relative to the stationary jaw; and wherein a displacement pin extends through the sliding slots and through the displacement passages connecting the moving jaw to the lever arms. a holster having an open end sized to receive a PIM device and having a cable opening extending from the open end on a side adjacent the open end to a side opposite the open end; and a clamping device sized and configured to attach the holster to a rail, the clamping device comprising: a stationary jaw secured to the holster; and a moving jaw disposed adjacent the stationary jaw, the stationary jaw and moving jaw forming an opening that receives the rail in a lateral direction and forming a passage therebetween to capture the rail; and a stationary jaw secured to the holster; and a moving jaw disposed adjacent the stationary jaw, the stationary jaw and moving jaw forming an opening that receives the rail in a lateral direction and forming a passage therebetween to capture the rail; and an actuator pivotable between an open position and a closed position to displace the moving jaw to open and close the clamping device; wherein the actuator includes a handle and a plurality of lever arms; wherein the handle is configured to be actuated to open the clamping device in order to attach or remove the PIM holder from the rail; wherein each of the plurality of lever arms comprises a pivot hole and a sliding slot, the pivot hole being located to correspond with a pivot hole in the stationary jaw and the sliding slot being located to correspond with a displacement passage through the moving jaw; wherein a pivot pin extends through the pivot holes in the stationary jaw and the pivot holes of the actuator and acts as an axle to define a pivot axis allowing the actuator to pivot about the pivot pin relative to the stationary jaw; and wherein a displacement pin extends through the sliding slots and through the displacement passages connecting the moving jaw to the lever arms.