Pressure actuated exposure mechanism for sterilant indicator
US5789175A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 4, 1997 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Aug 4, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61L2/28
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A sheet of chemically sensitive paper (54) that exhibits a measurable change in a physical property, such as color, when exposed to a chemical environment is inserted between two sections (20, 22) such that an area of the paper is exposed to the chemical environment through an opening (46) in the upper section. The lower section is connected to a piston (14) that is located in a chamber (10) such that an area at the top of the chamber is sealed by the piston. The piston responds to changes in pressure by moving within the chamber. As it does so, a ratchet mechanism (30) causes the upper and lower sections to rotate one step relative to each other. With each rotational step, a new area of the chemically sensitive paper is exposed to the chemical environment through the opening in the upper section. In this manner, a record of a series of chemical exposures is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.