Inventors:
Carleen J. Juran - Shoreview MN
James W. Busacker - St. Anthony MN
Michael B. Shelton - Minneapolis MN
Charles R. Brynelsen - North Oaks MN
Thomas P. Edery - Minneapolis MN
John D. Wahlstrand - Shoreview MN
Assignee:
Medtronic, Inc. - Minneapolis MN
International Classification:
A61N 1362
A61N 1378
Abstract:
An automatic, body-implantable medical device having at least two modes of operation is disclosed. The device is provided with circuitry for automatically detecting when the device has been implanted in a patient, so that the device can automatically switch from a first mode to a second mode of operation upon implantation. In one embodiment, the first mode is a power conserving mode in which one or more non-essential sub-systems of the device are disabled. Prior to detection of implant, at least two conditions of the device known to reflect whether the device has been implanted are monitored. After implant has been detected, situations in which power to the device is disrupted and then restored will cause the device to enter a predefined "power-on-reset" mode of operation. Prior to detection of implant, however, such conditions do not result in the device entering the power-on-reset mode, or this mode is reset. An Elective Replacement Indicator mode is also used which is based on measured impedance against a target battery impedance.