Switchable filter for rezeroing an in vivo pressure sensor
US5460183A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1993 |
| Grant date | Oct 24, 1995 |
| Priority date | — |
| Expiry date | Sep 28, 2013 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/02156
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A filter for rezeroing an in-vivo pressure sensor is disclosed. The filter operates in a signal mode and a rezero mode. In the signal mode, the filter is a low pass filter which filters out noise. In the rezero mode, the filter is a low pass filter which filters out the dynamic components of an in-vivo pressure signal caused by the rezeroing of the pressure sensor. The filter is switchable between the signal and rezero modes. The filter is implemented by means of an active two pole RC filter with a Butterworth response. A circuit is provided to shorten the time in which the filter reaches its final response characteristic. Also disclosed is a method for processing an output from an in vivo pressure transducer, the output signal comprising noise, a mean pressure signal and a dynamic pressure signal. The method comprises the steps of: receiving as an input, the output signal from the pressure transducer; filtering out the noise from the received input by means of a first filter circuit; and, filtering out the dynamic pressure signal while passing the mean pressure signal by connecting a second circuit to the first filter circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.