Index: sources/gui/qml/pages/pretreatment/create/PreTreatmentCreateStack.qml
===================================================================
diff -u -rf7e23265f6ac05c41c8411fac485f3a38640927a -r6f73e3ec5ba15c5c6ecc59191462e64e3bc36dfc
--- sources/gui/qml/pages/pretreatment/create/PreTreatmentCreateStack.qml	(.../PreTreatmentCreateStack.qml)	(revision f7e23265f6ac05c41c8411fac485f3a38640927a)
+++ sources/gui/qml/pages/pretreatment/create/PreTreatmentCreateStack.qml	(.../PreTreatmentCreateStack.qml)	(revision 6f73e3ec5ba15c5c6ecc59191462e64e3bc36dfc)
@@ -57,7 +57,7 @@
         title.text              : qsTr("Patient ID")
         header.backVisible      : true
         header.confirmVisible   : true
-        header.confirmEnabled   : _pretreatmentPatientIDEntry.text
+        header.confirmEnabled   : _pretreatmentPatientIDEntry.text.trim()
         TextEntry               { id  :     _pretreatmentPatientIDEntry
             property int topMarginContent   : 200
 
@@ -72,6 +72,9 @@
             }
             textInput.inputMethodHints  : Qt.ImhPreferLowercase
             textInput.echoMode          : TextInput.Normal
+            textInput.validator         : RegExpValidator {
+                regExp: Variables.regExp_PatientID
+            }
         }
     }