# US 2026/0054080 A1 · Preventing capacitor reverse biasing during discharge in medical device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0054080 A1 - Document ID: US20260054080A1 - Status: Published application - Kind: A1 - Application number: 18/998,856 - Filed: 2023-07-17 - Published: 2026-02-26 - Earliest claimed: 2022-07-29 - Assignees: Medtronic, Inc. - Applicants: Medtronic, Inc. - Inventors: Mark E. Viste; John D. Norton - Web page: https://patentgrep.com/patent/US20260054080A1 ## CPC - A61N 1/3931: {Protecting, e.g. back-up systems} - A61N 1/3981: {High voltage charging circuitry} - A61N 1/025: {Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors} - A61N 1/37: Monitoring; Protecting - A61N 1/3782: {producing a voltage above the power source level} - A61N 1/3918: {characterised by shock pathway, e.g. by electrode configuration} - A61N 1/39622: {Pacing therapy} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract A processing circuitry is configured to discharge capacitors to a discharge voltage level, such as by repeatedly discharging the capacitors when coupled in series and partially recharging one or more capacitors of the capacitors when coupled in parallel until the voltage across the capacitors coupled in series is approximately equal to the discharge voltage level. To discharge the capacitors, the processing circuitry is configured to discharge the capacitors when coupled in series to respective intermediate threshold voltage levels of a plurality of intermediate threshold voltage levels, and to partially recharge the one or more capacitors, the processing circuitry is configured to, in response to a voltage across the capacitors coupled in series reaching the respective intermediate threshold voltage levels, charge the one or more capacitors to respective intermediate common voltage levels of a plurality of intermediate common voltage levels when coupled in parallel. ## Claims ### Claim 1 A medical system comprising: therapy delivery circuitry comprising a plurality of capacitors; and processing circuitry configured to discharge the plurality of capacitors to a discharge voltage level, wherein to discharge the plurality of capacitors to the discharge voltage level, the processing circuitry is configured to repeatedly discharge the plurality of capacitors when coupled in series and partially recharge one or more capacitors of the plurality of capacitors when coupled in parallel until the voltage across the plurality of capacitors coupled in series is approximately equal to the discharge voltage level, wherein to discharge the plurality of capacitors when coupled in series, the processing circuitry is configured to discharge the plurality of capacitors when coupled in series to respective intermediate threshold voltage levels of a plurality of intermediate threshold voltage levels, and wherein to partially recharge the one or more capacitors when coupled in parallel, the processing circuitry is configured to, in response to a voltage across the plurality of capacitors coupled in series reaching the respective intermediate threshold voltage levels, charge the one or more capacitors of the plurality of capacitors to respective intermediate common voltage levels of a plurality of intermediate common voltage levels when coupled in parallel. ### Claim 2 (depends on 1) The medical system of claim 1, wherein to repeatedly discharge the plurality of capacitors when coupled in series and partially recharge the one or more capacitors of the plurality of capacitors, the processing circuitry is configured to: discharge the plurality of capacitors when coupled in series to a first intermediate threshold voltage level; in response to discharging the plurality of capacitors when coupled in series to the first intermediate threshold voltage level, couple the plurality of capacitors in parallel; recharge the one or more capacitors of the plurality of capacitors to a first intermediate common voltage level; in response to recharging the one or more capacitors of the plurality of capacitors to the first intermediate common voltage level, couple the plurality of capacitors in series; discharge the plurality of capacitors when coupled in series to a second intermediate threshold voltage level; in response to discharging the plurality of capacitors when coupled in series to the second intermediate threshold voltage level, couple the plurality of capacitors in parallel; recharge the one or more capacitors of the plurality of capacitors to a second intermediate common voltage level; in response to recharging the one or more capacitors of the plurality of capacitors to the second intermediate common voltage level, couple the plurality of capacitors in series; and discharge the plurality of capacitors when coupled in series to the discharge voltage level. ### Claim 3 (depends on 1) The medical system of claim 1, wherein to discharge the plurality of capacitors, the processing circuitry is configured to couple the plurality of capacitors that are coupled in series to a current source. ### Claim 4 (depends on 1) The medical system of claim 1, wherein to partially recharge the one or more capacitors, the processing circuitry is configured to couple the plurality of capacitors that are coupled in parallel to a transformer that is configured to recharge the one or more capacitors to the respective intermediate common voltage levels. ### Claim 5 (depends on 1) The medical system of claim 1, wherein to repeatedly discharge the plurality of capacitors when coupled in series and partially recharge the one or more capacitors of the plurality of capacitors, the processing circuitry is configured to repeatedly toggle the plurality of capacitors between a first circuit configuration and a second circuit configuration until the voltage across the plurality of capacitors coupled in series is approximately equal to the discharge voltage level, wherein the first circuit configuration comprises the capacitors coupled in series, and wherein the second circuit configuration comprises the capacitors coupled in parallel. ### Claim 6 (depends on 1) The medical system of claim 1, wherein the processing circuitry is configured to determine that the voltage across the capacitors coupled in series reached the respective intermediate threshold voltage levels of the plurality of intermediate threshold voltage levels based at least on one or more of a determination of amount to time that elapsed, on coulomb counting, or a voltage measurement. ### Claim 7 (depends on 1) The medical system claim 1, further comprising a cardiac medical device, wherein the cardiac medical device comprises the therapy delivery circuitry and the processing circuitry. ### Claim 8 (depends on 7) The medical system of claim 7, wherein the cardiac medical device comprises an extravascular implantable cardiac device (EV-ICD). ### Claim 9 (depends on 1) The medical system of claim 1, wherein the same plurality of capacitors are configured to deliver defibrillation therapy and pacing therapy. ### Claim 10 A method for preventing capacitor reverse biasing, the method comprising: discharging a plurality of capacitors to a discharge voltage level, wherein discharging the plurality of capacitors to the discharge voltage level comprises repeatedly discharging the plurality of capacitors when coupled in series and partially recharging one or more capacitors of the plurality of capacitors when coupled in parallel until a voltage across the plurality of capacitors coupled in series is approximately equal to the discharge voltage level, wherein discharging the plurality of capacitors when coupled in series comprises discharging the plurality of capacitors when coupled in series to respective intermediate threshold voltage levels of a plurality of intermediate threshold voltage levels, and wherein partially recharging the one or more capacitors when coupled in parallel comprises, in response to a voltage across the plurality of capacitors coupled in series reaching the respective intermediate threshold voltage levels, charging the one or more capacitors of the plurality of capacitors to respective intermediate common voltage levels of a plurality of intermediate common voltage levels when coupled in parallel. ### Claim 11 (depends on 10) The method of claim 10, wherein repeatedly discharging the plurality of capacitors when coupled in series and partially recharging the one or more capacitors of the plurality of capacitors comprises: discharging the plurality of capacitors when coupled in series to a first intermediate threshold voltage level; in response to discharging the plurality of capacitors when coupled in series to the first intermediate threshold voltage level, coupling the plurality of capacitors in parallel; recharging the one or more capacitors of the plurality of capacitors to a first intermediate common voltage level; in response to recharging the one or more capacitors of the plurality of capacitors to the first intermediate common voltage level, coupling the plurality of capacitors in series; discharging the plurality of capacitors when coupled in series to a second intermediate threshold voltage level; in response to discharging the plurality of capacitors when coupled in series to the second intermediate threshold voltage level, coupling the plurality of capacitors in parallel; recharging the one or more capacitors of the plurality of capacitors to a second intermediate common voltage level; in response to recharging the one or more capacitors of the plurality of capacitors to the second intermediate common voltage level, coupling the plurality of capacitors in series; and discharging the plurality of capacitors when coupled in series to the discharge voltage level. ### Claim 12 (depends on 10) The method claim 10, wherein partially recharging the one or more capacitors comprises coupling the plurality of capacitors that are coupled in parallel to a transformer that is configured to recharge the one or more capacitors to the respective intermediate common voltage levels. ### Claim 13 (depends on 10) The method of claim 10, wherein repeatedly discharging the plurality of capacitors when coupled in series and partially recharging the one or more capacitors of the plurality of capacitors comprises repeatedly toggling the plurality of capacitors between a first circuit configuration and a second circuit configuration until the voltage across the plurality of capacitors coupled in series is approximately equal to the discharge voltage level, wherein the first circuit configuration comprises the capacitors coupled in series, and wherein the second circuit configuration comprises the capacitors coupled in parallel. ### Claim 14 (depends on 10) The method of claim 10, further comprising determining that the voltage across the capacitors coupled in series reached the respective intermediate threshold voltage levels of the plurality of intermediate threshold voltage levels based at least on one or more of a determination of amount to time that elapsed, on coulomb counting, or a voltage measurement. ### Claim 15 (depends on 10) The method of claim 10, further comprising: delivering defibrillation therapy and pacing therapy with the same plurality of capacitors. ### Claim 16 (depends on 10) The method of claim 10, wherein discharging the plurality of capacitors comprises coupling the plurality of capacitors that are coupled in series to a current source. ### Claim 17 (depends on 10) The method of claim 10, wherein therapy delivery circuitry of a cardiac medical device comprises the plurality of capacitors. ### Claim 18 (depends on 17) The method of claim 17, wherein the cardiac medical device comprises an extravascular implantable cardiac device (EV-ICD). ### Claim 19 A computer-readable storage medium storing instructions thereon that when executed cause one or more processors to: discharge a plurality of capacitors to a discharge voltage level, wherein the instructions that cause the one or more processors to discharge the plurality of capacitors to the discharge voltage level comprise instructions that cause the one or more processors to repeatedly discharge the plurality of capacitors when coupled in series and partially recharge one or more capacitors of the plurality of capacitors when coupled in parallel until a voltage across the plurality of capacitors coupled in series is approximately equal to the discharge voltage level, wherein the instructions that cause the one or more processors to discharge the plurality of capacitors when coupled in series comprise instructions that cause the one or more processors to discharge the plurality of capacitors when coupled in series to respective intermediate threshold voltage levels of a plurality of intermediate threshold voltage levels, and wherein the instructions that cause the one or more processors to partially recharge the one or more capacitors when coupled in parallel comprise instructions that cause the one or more processors to, in response to a voltage across the plurality of capacitors coupled in series reaching the respective intermediate threshold voltage levels, charge the one or more capacitors of the plurality of capacitors to respective intermediate common voltage levels of a plurality of intermediate common voltage levels when coupled in parallel. ### Claim 20 (depends on 19) The computer-readable storage medium of claim 19, wherein the one or more processors comprise one or more processors of a cardiac medical device, and therapy delivery circuitry of the cardiac medical device comprises the plurality of capacitors.