Implantable medical apparatus for rate adaptive stimulation of a heart
US5273034A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 22, 1992 |
| Grant date | Dec 28, 1993 |
| Priority date | — |
| Expiry date | Apr 22, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/36521
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An implantable medical apparatus for stimulating a heart at a variable stimulation rate dependent on the respiratory rate, tidal volume, heart rate and stroke volume includes a measurement apparatus which measures impedance around the heart, a filter unit which splits the impedance signal into high-frequency and a low-frequency signal portions and two analyzers which respectively evaluate the signal portions and which emit the four parameter values as output signals. The product of respiratory rate times tidal volume is formed in a control apparatus. This product corresponds to respiratory minute volume, and the product of heart rate times stroke volume corresponds to cardiac output. Cardiac output is multiplied by a constant, and respiratory minute volume is subtracted from the product thus formed. The resulting different is equal to zero when blood oxygenation is optimum. The control apparatus controls the stimulation rate on the basis of the magnitude and sign of the difference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.