Automatic input impedance balancing for electrocardiogram (ECG) sensing applications
US6950694B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 2002 |
| Grant date | Sep 27, 2005 |
| Priority date | — |
| Expiry date | Oct 2, 2023 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/308
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A voltage sensing system includes input impedance balancing for electrocardiogram (ECG) sensing or other applications, providing immunity to common-mode noise signals while capable of use with two electrodes. Signals are received at first and second electrodes having associated impedances. An impedance circuit includes a feedback controller that adjusts an effective impedance associated with the second electrode based on a difference signal, a common mode signal, a phase-shifted (e.g., quadrature common mode) signal, and an impedance associated with the first electrode. As a result, signals associated with each electrode undergo a similar degree of gain/attenuation and/or phase-shift. This reduces common mode noise and enhances the signal-to-noise characteristics of a desired ECG or other output signal, without requiring the use of more than two electrodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.