# US 2018/0021571 A1 · Interventional medical systems and associated assemblies and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0021571 A1 - Document ID: US20180021571A1 - Status: Published application - Kind: A1 - Application number: 15/216,466 - Filed: 2016-07-21 - Published: 2018-01-25 - Earliest claimed: 2016-07-21 - Assignees: Medtronic, Inc. - Applicants: Medtronic, Inc. - Inventors: Thomas A. Anderson; Andrea J. Asleson; Michael D. Eggen; McKenna Rose Redmond; Zhongping Yang - Web page: https://patentgrep.com/patent/US20180021571A1 ## CPC - A61N 1/0592: {Introducing the lead through the pericardium with a needle} - A61B 17/3468: {for implanting or removing devices, e.g. prostheses, implants, seeds, wires (devices for implanting seeds A61M37/0069)} - A61N 1/37512: {Pacemakers} - A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators} - 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) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A catheter assembly includes a cap and a spring-biased tethering member coupled thereto. The cap includes first and second portions, and a transition zone extending therebetween. A girth of the first portion is sized to fit within a distal-most opening of the catheter assembly; and a girth of the second portion tapers from a first size at the transition zone, which is too large to fit within the distal-most opening, to a smaller size at a distal end of the cap. The spring-biased tethering member holds the cap in open and closed positions, when the cap first portion extends within the distal-most opening, and when the cap is separated from the distal-most opening, respectively. At the closed position, the first portion is approximately concentric with the distal-most opening, and at the open position, an entirety of the cap is laterally offset from the distal-most opening. ## Claims ### Claim 1 An interventional medical system comprising a relatively compact implantable medical device and a catheter assembly; the medical device comprising an electronic controller, a hermetically sealed housing containing the controller, an electrode electrically coupled to the controller, and a fixation member mounted to a distal end of the housing; the catheter assembly comprising an elongate inner tubular member, an elongate outer tubular member, and an end-cap subassembly; the outer tubular member defining an elongate lumen in which the inner tubular member extends, the outer tubular member extending from a proximal end thereof to a distal terminal end thereof, the distal terminal end defining a distal-most opening of the lumen, the lumen, in proximity to the distal-most opening, being sized to contain an entirety of the medical device therein, and the distal-most opening allowing passage of the medical device therethrough; the inner tubular member including a distal end configured to engage with a proximal end of the medical device, and the outer tubular member being moveable between a retracted position and an advanced position relative to the inner tubular member; and the end-cap subassembly of the catheter assembly comprising: a cap including a proximal end, a distal end, a first portion extending from the proximal end, a second portion extending from the distal end of the cap, and a transition zone extending between the first and second portions, the first portion having a girth sized to fit within the distal-most opening of the lumen of the outer tubular member, the second portion having a girth that tapers from a first size at the transition zone to a second, smaller size at the distal end, the girth of the second portion at the transition zone being too large to fit within the distal-most opening of the lumen of the outer tubular member; and a spring-biased tethering member secured to the catheter assembly and extending within the lumen of the outer tubular member, a distal end of the tethering member being coupled to the cap so that the tethering member extends from the proximal end of the cap, the tethering member being configured extend alongside the medical device, when the device is contained in the lumen of the outer tubular member, and to hold the cap in a closed position and in an open position; and wherein, when the outer tubular member of the catheter assembly is in the advanced position, a distance between the distal end of the inner tubular member and the distal-most opening of the outer tubular member is sufficient to accommodate the entirety of the medical device, the first portion of the cap, and the spring-biased tethering member extending alongside the device; when the first portion of the cap extends within the distal-most opening of the lumen of the outer tubular member of the catheter assembly, the tethering member holds the cap in the closed position, at which the first portion of the cap is approximately concentric with the distal-most opening; and when the cap is separated from the distal-most opening of the lumen of the outer tubular member of the catheter assembly, and the spring-biased tethering member extends out from the distal-most opening, the tethering member holds the cap in the open position, at which an entirety of the cap is laterally offset from the distal-most opening. ### Claim 2 (depends on 1) The system of claim 1, wherein the spring-biased tethering member of the end-cap subassembly of the catheter assembly comprises a proximal segment and a distal segment, the proximal segment having a length approximately equal to that of the inner tubular member and being in sliding engagement within a lumen of the inner tubular member, and the distal segment comprising a super-elastic wire having a pre-formed curvature. ### Claim 3 (depends on 1) The system of claim 1, wherein spring-biased tethering member of the end-cap subassembly of the catheter assembly comprises a super-elastic wire having a pre-formed curvature. ### Claim 4 (depends on 3) The system of claim 3, wherein the pre-formed curvature comprises a series of three bends, a first of the three bends extending around approximately 180 degrees, a second and third of the three bends extending adjacent one another, and each of the second and third bends extending around approximately 90 degrees. ### Claim 5 (depends on 3) The system of claim 3, wherein the super-elastic wire of the spring-biased tethering member has a rectangular cross-section. ### Claim 6 (depends on 1) The system of claim 1, wherein the end-cap subassembly of the catheter assembly further comprises a radiopaque marker extending around the transition zone of the cap. ### Claim 7 (depends on 1) The system of claim 1, wherein the end-cap subassembly of the catheter assembly further comprises a radiopaque marker extending within the second portion of the cap. ### Claim 8 (depends on 1) The system of claim 1, wherein the end-cap subassembly of the catheter assembly further comprises an atraumatic guide-wire tip being coupled to the cap and extending distally from the distal end of the cap. ### Claim 9 (depends on 1) The system of claim 1, wherein the cap transition zone of the end-cap subassembly of the catheter assembly defines an edge that abuts the distal terminal end of the outer tubular member of the catheter assembly, when the first portion of the cap is fitted within the distal-most opening of the lumen of the outer tubular member. ### Claim 10 An end-cap subassembly for a catheter assembly, the subassembly comprising: a cap including a proximal end, a distal end, a first portion extending from the proximal end, a second portion extending from the distal end, and a transition zone extending between the first and second portions, the first portion having a girth sized to fit within a distal-most opening of a lumen of the catheter assembly, the second portion having a girth that tapers from a first size at the transition zone to a smaller, second size at the distal end, the girth of the second portion at the transition zone being too large to fit within the distal-most opening of the lumen of the catheter assembly; and a spring-biased tethering member coupled to the cap and extending from the proximal end of the cap, the tethering member being configured extend within the lumen of the catheter assembly, alongside a relatively compact medical device that is contained within the lumen, and to hold the cap in a closed position and in an open position; and when the first portion of the cap extends within the distal-most opening of the lumen of the catheter assembly, the tethering member holds the cap in the closed position, the closed position being that at which the proximal portion of the cap is approximately concentric with the distal-most opening of the catheter assembly; and when the spring-biased tethering member extends out from the distal-most opening of the catheter assembly, the tethering member holds the cap in the open position, the open position being that at which an entirety of the cap is laterally offset from the distal-most opening. ### Claim 11 (depends on 10) The subassembly of claim 10, wherein spring-biased tethering member comprises a super-elastic wire having a pre-formed curvature. ### Claim 12 (depends on 11) The subassembly of claim 11, wherein the pre-formed curvature comprises a series of three bends a first of the three bends extending around approximately 180 degrees, a second and third of the three bends extending adjacent one another, and each of the second and third bends extending around approximately 90 degrees. ### Claim 13 (depends on 11) The subassembly of claim 11, wherein the super-elastic wire of the spring-biased tethering member has a rectangular cross-section. ### Claim 14 (depends on 10) The subassembly of claim 10, further comprising a radiopaque marker extending around the transition zone of the cap. ### Claim 15 (depends on 10) The subassembly of claim 10, further comprising a radiopaque marker extending within the second portion of the cap. ### Claim 16 (depends on 10) The subassembly of claim 10, further comprising an atraumatic guide-wire tip being coupled to the cap and extending distally from the distal end of the cap. ### Claim 17 (depends on 10) The subassembly of claim 10, wherein the transition zone of the cap defines an edge that abuts the distal terminal end of the outer tubular member of the catheter assembly when the first portion of the cap is fitted within the distal-most opening of the lumen of the outer tubular member. ### Claim 18 A method for assembling an interventional medical system, the method comprising: forming a curvature in a super-elastic wire; securing the super-elastic wire to a catheter assembly; coupling the super-elastic wire to a cap so that the formed curvature extends in close proximity to a proximal end of the cap; loading an implantable medical device into a lumen of the catheter assembly, through a distal-most opening of the catheter assembly; and positioning a first portion of the cap within the distal-most opening of the catheter assembly, so that the coupled super-elastic wire extends alongside the loaded device in the lumen, and a second portion of the cap extends distally from the distal terminal end, the distal terminal end of the catheter assembly defining the distal-most opening of the catheter assembly. ### Claim 19 (depends on 18) The method of claim 18, wherein securing the super-elastic wire to the catheter assembly comprises threading the super-elastic wire through an inner tubular member of the catheter assembly. ### Claim 20 (depends on 18) The method of claim 18, wherein securing the super-elastic wire to the catheter assembly comprises coupling the wire to an elongate rod and then threading the rod through an inner tubular member of the catheter assembly.