US 11,717,695 B2
High voltage therapy system with current control
Brandon Tyler Keil, Maple Grove, MN (US)
Assigned to CARDIAC PACEMAKERS, INC., St. Paul, MN (US)
Filed by CARDIAC PACEMAKERS, INC., St. Paul, MN (US)
Filed on Feb. 11, 2021, as Appl. No. 17/173,666.
Claims priority of provisional application 62/976,132, filed on Feb. 13, 2020.
Prior Publication US 2021/0252299 A1, Aug. 19, 2021
Int. Cl. A61N 1/39 (2006.01)
CPC A61N 1/39622 (2017.08) [A61N 1/3968 (2013.01); A61N 1/3975 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An implantable defibrillator comprising a housing and operational circuitry therein, the operational circuitry comprising:
at least one battery;
at least one high power capacitor;
a DC:DC conversion circuit configured to charge the at least one high power capacitor using current drawn from the at least one battery;
an H-bridge output circuit comprising first and second high side legs and first and second low side legs, each leg comprising a switch, the first high side and first low side legs coupled together at a first output node, and the second high side and second low side legs coupled together at a second output node;
a current monitoring subcircuit coupled to the first and second low side legs, the current monitoring subcircuit adapted to receive current through both of the first and second low side legs; and
a current control subcircuit coupling the at least one high power capacitor to the first and second high side legs, the current control subcircuit configured to receive a feedback signal from the current monitoring subcircuit to control current through the H-bridge;
wherein the current control subcircuit comprises a bootstrap circuit coupled to a first transistor that is configured to enable current flow to the H-bridge from the at least one high power capacitor.