Wireless capacitance pressure sensor
US7181975B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 2005 |
| Grant date | Feb 27, 2007 |
| Priority date | — |
| Expiry date | Sep 13, 2025 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/0002
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A wireless pressure sensor system has a pressure sensing capacitor and an inductor mounted on a common housing. The pressure sensing capacitor has a conductive diaphragm, a dielectric layer and a fixed electrode separated at least in part from the diaphragm by a gap formed in the housing. The electrode is arranged with a protrusion such that displacement of the diaphragm varies the area of capacitive contact with the electrode by rolling along the protrusion. The inductor coil and pressure sensing capacitor are connected to form a passive inductive-capacitive (LC) tank circuit. A remote interrogation circuit, inductively coupled to the pressure sensor inductor coil can be utilized to detect the resonant frequency of the LC tank which varies as a function of pressure sensed by the diaphragm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.