Dynamic bandwidth control in an implantable medical cardiac stimulator
US5843133A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1997 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Apr 14, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/395
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An implantable medical device for electrically stimulating the heart to beat includes a sense circuit for detecting cardiac electrical activity. The sense circuit includes a band pass filter with an adjustable frequency response. The frequency response can be repeatedly adjusted after implantation of the medical device and preferably is adjusted upon detection of the loss of normal sinus rhythm (NSR) in the heart's atria. The loss of NSR often indicates atrial fibrillation (AF), and the filter's frequency response is adjusted to increase the sensitivity of the sense circuit to the cardiac electrical activity typical during AF. The medical device is calibrated during implantation or at subsequent doctor visits with the aid of a calibration device external to the body. Cardiac electrical activity in the form of an electrogram is transmitted from the medical device to the external calibration device. The transmitted electrogram preferably includes both NSR and AF rhythms. The calibration device computes two sets of filter coefficients; one set for increased filter sensitivity during NSR and another set for increased sensitivity during AF. The coefficients are transmitted to the medica…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.