diff --git a/ontology/saref4ehaw.ttl b/ontology/saref4ehaw.ttl
index 999cb06f234377bc472b63fc0082d874ce7b304c..90f9301b18eb42d3806f9cdda1ba0ed2709f32ad 100644
--- a/ontology/saref4ehaw.ttl
+++ b/ontology/saref4ehaw.ttl
@@ -250,14 +250,6 @@ s4ehaw:hasMeasurement rdf:type owl:ObjectProperty ;
                       rdfs:label "has measurement"@en .
 
 
-###  https://saref.etsi.org/saref4ehaw/hasOperatingConstraint
-s4ehaw:hasOperatingConstraint rdf:type owl:ObjectProperty ;
-                              rdfs:domain s4ehaw:HealthDevice ;
-                              rdfs:range s4ehaw:OperatingConstraint ;
-                              rdfs:comment "The operating constraints of a health device, e.g. recommended humidity and temperature range..."@en ;
-                              rdfs:label "has operating constraint"@en .
-
-
 ###  https://saref.etsi.org/saref4ehaw/hasParticipant
 s4ehaw:hasParticipant rdf:type owl:ObjectProperty ;
                       rdfs:domain s4ehaw:MeasurementCollectionSession ;
@@ -1021,7 +1013,11 @@ s4ehaw:HealthActuator rdf:type owl:Class ;
 
 ###  https://saref.etsi.org/saref4ehaw/HealthDevice
 s4ehaw:HealthDevice rdf:type owl:Class ;
-                    rdfs:subClassOf saref:Device ;
+                    rdfs:subClassOf saref:Device ,
+                                    [ rdf:type owl:Restriction ;
+                                      owl:onProperty saref:hasProperty ;
+                                      owl:someValuesFrom saref:Property
+                                    ] ;
                     rdfs:comment "Health devices, e.g. BAN hub, health sensor/actuator/Wereable."@en ;
                     rdfs:label "Health Device"@en .
 
@@ -1314,6 +1310,20 @@ s4ehaw:Lying rdf:type owl:NamedIndividual ,
              rdfs:label "Lying"@en .
 
 
+###  https://saref.etsi.org/saref4ehaw/MaximumRecommended
+s4ehaw:MaximumRecommended rdf:type owl:NamedIndividual ,
+                                   saref:Property ;
+                          skos:broader s4ehaw:Recommended ;
+                          rdfs:comment "The maximum recommended property value for some entity"@en .
+
+
+###  https://saref.etsi.org/saref4ehaw/MinimumRecommended
+s4ehaw:MinimumRecommended rdf:type owl:NamedIndividual ,
+                                   saref:Property ;
+                          skos:broader s4ehaw:Recommended ;
+                          rdfs:comment "The minimum recommended property value for some entity"@en .
+
+
 ###  https://saref.etsi.org/saref4ehaw/MobilityImpairment
 s4ehaw:MobilityImpairment rdf:type owl:NamedIndividual ,
                                    s4ehaw:Impairment ;
@@ -1358,6 +1368,12 @@ s4ehaw:Prevention rdf:type owl:NamedIndividual ,
                   rdfs:label "Prevention"@en .
 
 
+###  https://saref.etsi.org/saref4ehaw/Recommended
+s4ehaw:Recommended rdf:type owl:NamedIndividual ,
+                            saref:Property ;
+                   rdfs:comment "The recommended property values for some entity"@en .
+
+
 ###  https://saref.etsi.org/saref4ehaw/Running
 s4ehaw:Running rdf:type owl:NamedIndividual ,
                         s4ehaw:Posture ;