Device for eliminating ringing in filtered ECG signals
US5532951A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Jun 27, 2014 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/30
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A device for eliminating ringing in filtered ECG signals includes an analog-to-digital for converting the ECG input signals into a series of digital values, and a filter unit connected to the output of the analog-to digital converter. The filter unit includes a recursive IIR-filter and a subsequent allpass filter with a phase shift which is equal to twice the phase shift of the IIR filter. The allpass filtering is performed time-reversed with respect to the IIR filtering. In a method for producing an allpass filter, for use in the above device, having a phase shift which is equal to twice the phase shift of an IIR filter, the IIR filter having zero points situated on the unity circle in the Z-plane, the zero points of the IIR filter are replaced by new zero points obtained by reflecting the poles of the filter in the unity circle in the Z-plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.