Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5127400 | Ventilator exhalation valve | Douglas F. DeVries, Malcolm Williams, J. Kelly Dack, Randy P. Hagen | 1992-07-07 |
| 4993269 | Variable orifice flow sensing apparatus | Michael G. Norton, Douglas F. DeVries | 1991-02-19 |