Moisture indicator for heat and moisture exchange devices
US7913640B2 · kind B2 · utility
13Cited by
24References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 9, 2007 |
| Grant date | Mar 29, 2011 |
| Priority date | — |
| Expiry date | Apr 8, 2029 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2205/584
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
There is provided a moisture indicator for a heat and moisture exchange (HME) device that uses a pre-colorant and an activator applied to an inner surface of the HME device. The colorant undergoes a color change of Delta E (ΔE) of equal to or greater than 3 units upon exposure to moisture but not upon exposure to high humidity. The colorant is visually obvious to the unaided human eye under normal light conditions through the body of the device. The HME device with the visual indicator for moisture can indicate to the care-giver that it is time to change the HME device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.