# BTT: Humidifier, Respiratory Gas, (Direct Patient Interface)

- Device class: 2; regulation: 21 CFR 868.5450; FDA's rule: 510(k) required
- FDA decisions: 222
- 510(k) review time 2021–2025: median 240 days (middle half 166–277)
- Recalls: 22 (4 Class I)
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026; MAUDE to Sep 30, 2026

## Decisions per year (last 10)
- 2017: 3
- 2018: 2
- 2019: 1
- 2020: 2
- 2021: 2
- 2022: 3
- 2023: 7
- 2024: 7
- 2025: 4
- 2026: 4

## Most-cited predicates
- K073706: Respiratory Humidifier, Model MR850 (2008), cited by 11
- K983112: Respiratory Humidifier, Model # MR850 (1998), cited by 9
- K934140: MR290 Humidification Chamber Single Use (1994), cited by 8
- K162553: AirSpiral Heated Breathing Tube (2018), cited by 8
- K913368: Models MR700/MR720/MR730 Dual Servo Resp Humid Acc (1992), cited by 7
- K131895: Airvo 2 Humidifier, Myairvo 2 Humidifier (2013), cited by 7
- K033710: MR850 Respiratory Humidifier, Model MR850JHU (2004), cited by 6
- K000401: Vapotherm, Model 2000I (2000), cited by 5
- K020332: Respiratory Humidifier, Model MR850 (2003), cited by 5
- K042245: Vapotherm Model#2000I, 200H (2004), cited by 4

Source page: https://510kreport.com/product-code/BTT
Data by year (CSV): https://510kreport.com/product-code/BTT.csv