| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Measurement of mixed venous partial pressure of oxygen | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of partial pressure of oxygen in blood | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of venous partial pressure of oxygen | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of capillary partial pressure of oxygen | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of transcutaneous partial pressure of oxygen | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Venous oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Mixed venous oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Capillary oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen saturation at periphery | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Blood oxygen concentration measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Arterial oxygen concentration measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Capillary oxygen concentration measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Mixed venous oxygen concentration measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Venous oxygen concentration measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in blood | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in arterial blood | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in mixed venous blood (procedure) | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in venous blood | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH profile measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Overnight pulse oximetry | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Point pH monitoring | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Period pH monitoring | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH reflux test | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen saturation measurement, arterial | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Scalp pH measurement (procedure) | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Intracardiac oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Superior vena cava oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Conjunctival oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Invasive oximetry | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Jugular bulb oxygen saturation measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Invasive oxygen saturation monitoring | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH, combined acid measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH, free acid measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH, total acid measurement (procedure) | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen measurement, partial pressure, arterial (procedure) | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement, arterial | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Analysis of arterial blood gases and pH | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Esophagus acid reflux test with intraluminal pH electrode | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement, body fluid | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement, venous | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of feces pH | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Feces: excessive acidity | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Feces: excessive alkalinity | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of vomit pH | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Fluid sample total acid measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygenation index measurement | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Feces pH NOS | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Vomit pH NOS | Has measured component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of mixed venous partial pressure of oxygen | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of partial pressure of oxygen in blood | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of venous partial pressure of oxygen | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of capillary partial pressure of oxygen | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of transcutaneous partial pressure of oxygen | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Venous oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Mixed venous oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Capillary oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen saturation at periphery | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Blood oxygen concentration measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Arterial oxygen concentration measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Capillary oxygen concentration measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Mixed venous oxygen concentration measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Venous oxygen concentration measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in blood | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in arterial blood | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in mixed venous blood (procedure) | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of oxygen dissolved in venous blood | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH profile measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Overnight pulse oximetry | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Point pH monitoring | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Period pH monitoring | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH reflux test | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen saturation measurement, arterial | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Scalp pH measurement (procedure) | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Intracardiac oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Superior vena cava oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Conjunctival oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Invasive oximetry | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Jugular bulb oxygen saturation measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Invasive oxygen saturation monitoring | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH, combined acid measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH, free acid measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH, total acid measurement (procedure) | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygen measurement, partial pressure, arterial (procedure) | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement, arterial | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Analysis of arterial blood gases and pH | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Esophagus acid reflux test with intraluminal pH electrode | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement, body fluid | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| pH measurement, venous | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of feces pH | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Feces: excessive acidity | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Feces: excessive alkalinity | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Measurement of vomit pH | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Fluid sample total acid measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Oxygenation index measurement | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  | 
| Feces pH NOS | Component | False | Hydrogen ion concentration | Inferred relationship | Some |  |