| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Magill breathing circuit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Bain breathing circuit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Lack breathing circuit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Pediatric breathing circuit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Humphrey ADE breathing circuit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| T piece with bag | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| T piece without bag | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| T piece with bag and adjustable pressure-limiting valve | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia breathing circuit | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Circle system | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Waters' circuit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Waters' circuit without absorber | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Breathing circuit connector | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Expiratory valve | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Carbon dioxide absorbent | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia unit, portable | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia workstation, general-purpose | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia workstation, closed-circuit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Inhalational analgesia unit | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Breathing circuit bag, reusable | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Breathing circuit bag, single-use | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Breathing circuit tube | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Demand valve | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Pressure relief valve, reusable | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Pressure relief valve, single-use | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Positive end expiratory pressure valve, reusable | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Pulmonary function valve | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia ventilator | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Patient monitoring system module, multiple-gas | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Positive end expiratory pressure valve, single use | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia breathing circuit circulator | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia unit, wall-mounted | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthesia unit, mobile | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Stationary electric high-frequency ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Neonatal/adult intensive-care ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| General-purpose intensive-care ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Non-rebreathing valve, reusable | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Portable pneumatic ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Transport electric ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Halogenated vapor absorber | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Neonatal intensive-care ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Dental anesthesia system | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Viral filter | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Stationary pneumatic high-frequency ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Portable pneumatic high-frequency ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Transport pneumatic high-frequency ventilator | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Anesthetic gas absorption/desorption device | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Isoflurane and/or sevoflurane recycling anesthesia vaporizer | Is a | True | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Non-rebreathing valve, single-use | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Respiratory gas thermometer | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Heat/moisture exchanger/microbial filter, non-sterile | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Respiratory gas heating wire, infant | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Respiratory gas heating wire, adult | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  | 
| Respiratory gas heating wire electrical connection cable | Is a | False | Breathing circuit | Inferred relationship | Existential restriction modifier |  |