# US 12,000,448 B2 · Biostimulator transport system having torque limiter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,448 B2 - Document ID: US12000448B2 - Status: Granted - Kind: B2 - Application number: 17/018,689 - Filed: 2020-09-11 - Published: 2021-03-25 - Granted: 2024-06-04 - Earliest claimed: 2019-09-20 - Assignees: Pacesetter, Inc. - Applicants: Pacesetter, Inc. - Inventors: David Rickheim; Scott Kerns; Daniel Coyle - Web page: https://patentgrep.com/patent/US12000448B2 ## CPC - F16D 7/04: of the ratchet type (similar gearings based on repeated accumulation and delivery of inertia-energy F16H33/08; {overload clutches of the ratchet type F16D43/202}) - A61N 1/372: Arrangements in connection with the implantation of stimulators - A61N 1/37518: {Anchoring of the implants, e.g. fixation} - A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators} - A61N 2001/0578: {having means for removal or extraction} - A61N 2001/058: {Fixing tools} - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - 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 biostimulator transport system, such as a biostimulator retrieval system, having a torque limiter to allow a torque shaft to slip rotationally relative to a handle, is described. The torque limiter can connect the torque shaft to the handle, and can include a slip mechanism, such as a flat spring or apposed clutch faces, that allow the torque shaft to slip relative to the handle when a resistance torque at a distal end of the torque shaft exceeds a torque threshold. Accordingly, torque can be applied to a biostimulator by the torque shaft with a reduced likelihood of over-torqueing the biostimulator within the target tissue. Other embodiments are also described and claimed. ## Claims ### Claim 1 A torque shaft assembly, comprising: an elongated flexible tubular member; a docking cap coupled to the elongated flexible tubular member, wherein the docking cap has a docking cavity to receive an attachment feature of a biostimulator; a torque shaft extending from a proximal shaft end distally through the elongated flexible tubular member to a distal shaft end coupled to the docking cap; and a torque limiter including a torque puck mounted on the proximal shaft end of the torque shaft, a torque shuttle rotationally coupled to the torque puck, and a slip mechanism between the torque puck and the torque shuttle to allow the torque puck to slip relative to the torque shuttle based on a resistance torque at the docking cap. ### Claim 2 (depends on 1) The torque shaft assembly of claim 1, wherein the torque puck and the torque shuttle rotate together when the resistance torque is below a torque threshold, and wherein the torque puck slips rotationally relative to the torque shuttle when the resistance torque at the docking cap is above the torque threshold. ### Claim 3 (depends on 1) The torque shaft assembly of claim 1, wherein the slip mechanism includes a flat spring fixed to one of the torque puck or the torque shuttle, and wherein the flat spring engages a groove in the other of the torque puck or the torque shuttle. ### Claim 4 (depends on 3) The torque shaft assembly of claim 3, wherein the torque puck includes a plurality of radial teeth, and wherein the flat spring is fixed to the torque shuttle and extends into the groove between the plurality of radial teeth. ### Claim 5 (depends on 1) The torque shaft assembly of claim 1, wherein the slip mechanism includes an inner shuttle containing the torque puck, wherein the inner shuttle has an inner clutch face apposed to an outer clutch face of the torque shuttle, and wherein the slip mechanism includes a bias element coupled to the inner shuttle and the torque shuttle to press the inner clutch face against the outer clutch face. ### Claim 6 (depends on 5) The torque shaft assembly of claim 5, wherein the inner shuttle is longitudinally movable relative to the torque shuttle. ### Claim 7 (depends on 5) The torque shaft assembly of claim 5, wherein the inner clutch face and the outer clutch face are non-planar meshing surfaces. ### Claim 8 (depends on 7) The torque shaft assembly of claim 7, wherein the non-planar meshing surfaces include one or more clutch dogs. ### Claim 9 (depends on 1) The torque shaft assembly of claim 1, wherein the slip mechanism includes a ball plunger fixed to one of the torque puck or the torque shuttle, and wherein the ball plunger engages a recess in the other of the torque puck or the torque shuttle. ### Claim 10 (depends on 1) The torque shaft assembly of claim 1, wherein the slip mechanism includes a shear pin fixed to and extending between the torque puck and the torque shuttle. ### Claim 11 A biostimulator transport system, comprising: an elongated flexible tubular member; a docking cap coupled to the elongated flexible tubular member, wherein the docking cap has a docking cavity to receive an attachment feature of a biostimulator a torque shaft extending from a proximal shaft end distally through the elongated flexible tubular member to a distal shaft end coupled to the docking cap; a handle having a handle cavity; and a torque limiter in the handle cavity, wherein the torque limiter includes a torque puck mounted on the proximal shaft end of the torque shaft, a torque shuttle coupled to the handle and the torque puck, and a slip mechanism between the torque shuttle and the torque puck to allow the torque shaft to rotate relative to the handle based on a resistance torque on the torque shaft. ### Claim 12 (depends on 11) The biostimulator transport system of claim 11, wherein the handle includes a distal handle portion longitudinally and rotationally movable relative to a proximal handle portion, wherein the torque shuttle is longitudinally fixed and rotationally movable relative to the distal handle portion, and wherein the torque shuttle is longitudinally movable and rotationally fixed relative to the proximal handle portion. ### Claim 13 (depends on 12) The biostimulator transport system of claim 12, wherein the handle cavity includes a distal handle cavity within the distal handle portion and a proximal handle cavity within the proximal handle portion, and wherein the torque shuttle is contained within the distal handle cavity and the proximal handle cavity. ### Claim 14 (depends on 11) The biostimulator transport system of claim 11, wherein the slip mechanism includes a flat spring fixed to one of the torque puck or the torque shuttle, and wherein the flat spring engages a groove in the other of the torque puck or the torque shuttle. ### Claim 15 (depends on 11) The biostimulator transport system of claim 11, wherein the slip mechanism includes an inner shuttle containing the torque puck, wherein the inner shuttle has an inner clutch face apposed to an outer clutch face of the torque shuttle, and wherein the slip mechanism includes a bias element coupled to the inner shuttle and the torque shuttle to press the inner clutch face against the outer clutch face. ### Claim 16 (depends on 11) The biostimulator transport system of claim 11, wherein the slip mechanism includes a ball plunger fixed to one of the torque puck or the torque shuttle, wherein the ball plunger engages a recess in the other of the torque puck or the torque shuttle. ### Claim 17 (depends on 11) The biostimulator transport system of claim 11, wherein the slip mechanism includes a shear pin fixed to and extending between the torque puck and the torque shuttle. ### Claim 18 A biostimulator retrieval system, comprising: an elongated flexible tubular member; a docking cap coupled to the elongated flexible tubular member, wherein the docking cap has a docking cavity to receive an attachment feature of a biostimulator; a torque shaft extending from a proximal shaft end distally through the elongated flexible tubular member to a distal shaft end coupled to the docking cap; a handle; a torque limiter including a torque puck mounted on the proximal shaft end of the torque shaft, a torque shuttle coupled to the handle, and a slip mechanism between the torque shuttle and the torque puck to allow the torque shaft to rotate relative to the handle based on a resistance torque at the docking cap; and a snare extending through the torque puck, the torque shaft, and the docking cap. ### Claim 19 (depends on 18) The biostimulator retrieval system of claim 18, wherein the snare includes a snare tube having a central lumen and one or more snare loops extending through the central lumen. ### Claim 20 (depends on 19) The biostimulator retrieval system of claim 19, wherein the torque shaft has a shaft lumen, and wherein the snare tube is longitudinally movable within the shaft lumen.