System and method for measuring cardiac activity
US5991661A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1997 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Oct 17, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/36542
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An implantable cardiac stimulation device, such as a pacemaker or an implantable cardioverter-defibrillator, that includes an accelerometer-based activity sensor that processes one or more signals from the activity sensor to obtain parameters that are indicative of the heartbeat of the patient. The implantable cardiac stimulation device determines when the patient is at rest and the activity sensor provides a signal that corresponds to the acceleration of the sensor due to the heartbeat of the patient. This acceleration signal is integrated over time once to provide a contractility parameter, which is indicative of the contractility of the heart and is integrated over time twice to provide a displacement parameter, which is indicative of the displacement of the heart wall during the heartbeat. This displacement parameter is thereby indicative of the volume of blood pumped by the heart. A microprocessor uses either the contractility parameter, the displacement parameter or both to modify the delivery of therapeutic stimulation pulses to the heart.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.