Battery monitoring means and method for an implantable tissue stimulator
US4324251A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1980 |
| Grant date | Apr 13, 1982 |
| Priority date | — |
| Expiry date | Jun 10, 2000 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/37252
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A battery monitoring means for an implantable tissue stimulator in which a signal related to the internal impedance of an implanted battery is telemetered to an external receiving means. More specifically, the implanted battery is loaded by a varible load until current flowing through the battery lowers its output voltage until it has a predetermined relationship with respect to a reference voltage. The current flowing through the battery to achieve the predetermined relationship is directly related to the internal impedance of the battery. A voltage related to the value of this current is then telemetered to the external receiving means. In a specific embodiment, the variable load is a field effect transistor (FET) connected as a source follower. The impedance of the FET is controlled by the output of an operational amplifier having as inputs the reference voltage and a voltage related to the output voltage of the battery. The monitoring means operates in a closed-loop servo system manner until the two input voltages to the operational amplifier are equal. The other terminal of the battery is connected to a shunting resistor. Thus the voltage drop across the shunting resistor is r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.