Abstract: The present invention relates to a step-up converter with a plurality of levels, in particular for use in an implantable medical device, comprising a transformer (11) comprising a single primary winding and a single secondary winding; a primary circuit (6) comprising the single primary winding; and a secondary circuit (7) comprising the single secondary winding and a plurality of step-up levels, each of the step-up levels comprising a first diode (4a, 4b, 4c, 4d, 4e, 4f) and a second diode (10a, 10b, 10c, 10d, 10e, 10f) and a first capacitor (9a, 9b, 9c, 9d, 9e, 9f) and a second capacitor (3a, 3b, 3c, 3d, 3e, 3f), wherein the first capacitors (9a, 9b, 9c, 9d, 9e, 9f) of the plurality of step-up levels are connected in series or in parallel with one another.

Abstract: A method for determining usable capacity of a battery of an active implantable medical device comprising a radiofrequency (RF) communication unit for transmitting data by RF over a communication period, wherein the usable capacity of the battery enables the active implantable medical device to transmit data by RF via the RF communication unit. The method includes measuring a value for the voltage of the battery which is representative of an instantaneous voltage drop of the battery as a result of a current draw on the battery, comparing the voltage of the battery with a predetermined threshold voltage VBS, and transmitting an alert message to a second device when the measured voltage of the battery crosses the predetermined threshold voltage.

Abstract: A method for determining usable capacity of a battery of an active implantable medical device comprising a radiofrequency (RF) communication unit for transmitting data by RF over a communication period, wherein the usable capacity of the battery enables the active implantable medical device to transmit data by RF via the RF communication unit. The method includes measuring a value for the voltage of the battery which is representative of an instantaneous voltage drop of the battery as a result of a current draw on the battery, comparing the voltage of the battery with a predetermined threshold voltage VBS, and transmitting an alert message to a second device when the measured voltage of the battery crosses the predetermined threshold voltage.