Method and apparatus for cardiac impedance sensing
US5722997A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1996 |
| Grant date | Mar 3, 1998 |
| Priority date | — |
| Expiry date | Sep 17, 2016 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/36521
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and apparatus for measuring impedance of heart tissue or the leads associated with a cardiac stimulation apparatus involves charging a capacitor, storing the value of the voltage across the capacitor when charged, discharging the capacitor into said lead/heart system and storing the voltage on said capacitor when discharged. The two voltages may then be used to determine the combined impedance of the lead and the heart tissue. This may be advantageously accomplished by using separate circuits to measure each of the voltages of the capacitor and storing those voltages. These voltages then may be applied to an analog-to-digital converter which converts the ratio of said voltages to digital form. This value can then be used to calculate the combined impedance of the heart tissue or the lead. If one of the two impedances is known the other can then be easily determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.