# US 12,178,662 B2 · Catheter and spring element for contact force sensing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,178,662 B2 - Document ID: US12178662B2 - Status: Granted - Kind: B2 - Application number: 15/986,667 - Filed: 2018-05-22 - Published: 2018-11-29 - Granted: 2024-12-31 - Earliest claimed: 2017-05-23 - Assignees: Boston Scientific Scimed, Inc. - Applicants: Boston Scientific Scimed Inc. - Inventors: Kimberly A. Miklos; Joseph Walker; Edward J. Maierhofer; Garth Mindermann; Devon N Arnholt; Todd College - Web page: https://patentgrep.com/patent/US12178662B2 ## CPC - A61B 90/06: {Measuring instruments not otherwise provided for} - A61B 5/6852: {Catheters} - A61B 5/6885: {Monitoring or controlling sensor contact pressure} - A61B 18/1492: {having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence)} - A61B 5/4848: {Monitoring or testing the effects of treatment, e.g. of medication} - A61B 90/37: {Surgical systems with images on a monitor during operation} - A61B 2018/00351: {Heart} - A61B 2018/00577: {Ablation} - A61B 2090/065: {for measuring contact or contact pressure} - A61B 2090/378: {using ultrasound} - A61B 2090/3784: {both receiver and transmitter being in the instrument or receiver being also transmitter} - A61B 2218/002: Irrigation - A61M 2025/0002: {with a pressure sensor at the distal end} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract A spring element for a contact force sensing medical catheter. The spring element includes a first ring, a second ring spaced apart from the first ring, a plurality of struts connecting the first ring to the second ring, and a plurality of interlocking features. The second ring and the first ring are coaxially aligned with a longitudinal axis of the spring element. The plurality of struts is configured to permit elastic, relative axial and radial displacement between the first ring and the second ring. The plurality of interlocking features is configured to limit the relative axial and radial displacement between the first ring and the second ring. ## Claims ### Claim 1 A spring element for a contact force sensing medical catheter, the spring element comprising: a first ring; a second ring spaced apart from the first ring, the second ring and the first ring coaxially aligned with a longitudinal axis of the spring element; and a plurality of struts connecting the first ring to the second ring, each of the plurality of struts connected to an adjacent strut by an interconnect configured to define a space between adjacent struts, the plurality of struts configured to elastically deform so as to permit relative axial and radial displacement between the first ring and the second ring; wherein each of the plurality of struts includes a plurality of interlocking features configured to limit the relative axial and radial displacement between the first ring and the second ring, each of the plurality of interlocking features interlocking with an adjacent strut of the plurality of struts, wherein at least some of the interlocking features include a head portion and a neck portion, the head portion having a first axially facing surface facing away from the neck portion and a second axially facing surface facing a direction opposite the first surface, wherein the first surface and the second surface are substantially parallel to one another. ### Claim 2 (depends on 1) The spring element of claim 1, wherein each of the plurality of struts extends at least partially in a circumferential direction to permit elastic relative axial and radial displacement between the first ring and the second ring. ### Claim 3 (depends on 2) The spring element of claim 2, wherein each of the plurality of struts extends at least substantially in the circumferential direction and the plurality of struts are interconnected. ### Claim 4 (depends on 2) The spring element of claim 2, wherein each of the plurality of struts extends directly between the first ring and the second ring and in both the circumferential direction and an axial direction. ### Claim 5 (depends on 1) The spring element of claim 1, wherein each of the interlocking features extends between the first ring and one of the plurality of struts adjacent to the first ring, between the second ring and one of the plurality of struts adjacent to the second ring, or between two of the plurality of struts adjacent to each other. ### Claim 6 (depends on 5) The spring element of claim 5, wherein each of the interlocking features includes: a tab extending from one of the first ring, the second ring, or the one of the plurality of struts; and an opening defined in one of the first ring, the second ring, or another one of the plurality of struts adjacent to the one of the first ring, the second ring, or the one of the plurality of struts from which the tab extends, the opening configured to engage the tab. ### Claim 7 (depends on 6) The spring element of claim 6, wherein for at least some of the interlocking features: the tab includes the head portion and the neck portion connecting the head portion to the one of the first ring, the second ring, or the one of the plurality of struts, the head portion being wider than the neck portion; and the opening includes a wide region and a narrow region, wherein the wide region is larger wider in a circumferential direction and longer in an axial direction than the head portion of the tab, the narrow region is wider than the neck portion of the tab, and the narrow region is narrower than the head portion of the tab, the head portion of the tab contained within the wide region and the neck portion of the tab extending through the narrow region such that the opening engages the tab to limit the relative axial and radial displacement between the first ring and the second ring. ### Claim 8 A spring element for a contact force sensing medical catheter, the spring element comprising: a first ring; a second ring spaced apart from the first ring, the second ring and the first ring coaxially aligned with a longitudinal axis of the spring element; a plurality of struts configured to elastically deform to moveably couple the first ring to the second ring, each of the plurality of struts connected to an adjacent strut by an interconnect configured to define a space between adjacent struts; and wherein the plurality of struts includes a plurality of interlocking features configured to limit the relative axial and radial displacement between the first ring and the second ring, each of the interlocking features formed in the first ring and engaging one of the plurality of struts adjacent to the first ring, formed in one of the plurality of struts adjacent to the second ring and engaging the second ring, or formed in one of the plurality of struts and engaging a strut adjacent to the one of the plurality of struts, each of the interlocking features including: a tab including a head portion and a neck portion extending from one of the first ring or the one of the plurality of struts; and an opening defined in one of the second ring, or another one of the plurality of struts adjacent to the one of the first ring or the one of the plurality of struts from which the tab extends, the opening configured to engage the tab, the opening including a wide region and a narrow region, wherein the wide region contains the head portion and is wider in a circumferential direction and longer in an axial direction than the head portion, wherein the narrow region is wider than the neck portion of the tab, the narrow region is narrower than the head portion of the tab, and wherein the narrow region is defined by two opposing surfaces substantially parallel to the neck portion. ### Claim 9 A catheter adapted to measure a contact force, the catheter comprising: a proximal segment; a distal segment; a spring segment extending from the proximal segment to the distal segment, the spring segment configured to permit relative displacement between the distal segment and the proximal segment in response to an application of the force on the distal segment, the spring segment including: a spring element including: a first ring; a second ring spaced apart from the first ring, the second ring and the first ring coaxially aligned with a longitudinal axis of the spring element; and a plurality of struts configured to elastically deform, the plurality of struts elastically coupling the first ring to the second ring and configured to permit elastic, relative axial and radial displacement between the first ring and the second ring; wherein the plurality of struts includes a plurality of interlocking features configured to limit the relative axial and radial displacement between the first ring and the second ring, wherein each of the plurality of interlocking features is formed in a strut of the plurality of struts and interlocks with an adjacent strut of the plurality of struts; wherein the plurality of interlocking features includes: a tab including a head portion and a neck portion connecting the head portion to one of the first ring, the second ring, or one of the plurality of struts, the head portion being wider than the neck portion; and an opening including a wide region and a narrow region, wherein the wide region is wider in a circumferential direction and longer in an axial direction than the head portion, wherein the narrow region is wider than the neck portion of the tab, the narrow region is narrower than the head portion of the tab, and wherein the narrow region is defined by two opposing surfaces substantially parallel to the neck portion, the head portion of the tab contained within the wide region and the neck portion of the tab extending through the narrow region such that the opening engages the tab to limit the relative axial and radial displacement between the first ring and the second ring; and a plurality of sensing elements configured to output a plurality of signals indicative of the relative displacement between the proximal segment and the distal segment. ### Claim 10 (depends on 9) The catheter of claim 9, wherein each of the plurality of struts extends at least partially in a circumferential direction to permit elastic relative axial and radial displacement between the first ring and the second ring, and the plurality of struts are interconnected. ### Claim 11 (depends on 9) The catheter of claim 9, wherein the each of the interlocking features extends between the first ring and one of the plurality of struts adjacent to the first ring, between the second ring and one of the plurality of struts adjacent to the second ring, or between two of the plurality of struts adjacent to each other. ### Claim 12 (depends on 11) The catheter of claim 11, wherein each of the interlocking features includes: the tab extending from one of the first ring, the second ring, or the one of the plurality of struts; and the opening is defined in one of the first ring, the second ring, or another one of the plurality of struts adjacent to the one of the first ring, the second ring, or the one of the plurality of struts from which the tab extends, the opening configured to engage the tab. ### Claim 13 (depends on 9) The catheter of claim 9, wherein the spring element is a one-piece spring element. ### Claim 14 (depends on 9) The catheter of claim 9, wherein the plurality of sensing elements include a plurality of inductive sensors configured to signal a change in inductance caused by changes in the relative displacement between the proximal segment and the distal segment. ### Claim 15 (depends on 9) The catheter of claim 9, wherein: the proximal segment includes a proximal hub; and the distal segment includes a distal hub, wherein the first ring of the spring element is attached to the proximal hub and the second ring of the spring element is attached to the distal hub. ### Claim 16 (depends on 15) The catheter of claim 15, wherein: when the distal segment is in a base orientation with respect to the proximal segment, the proximal and distal hubs are coaxially aligned with the longitudinal axis of the spring element; and when the distal segment is moved out of the base orientation with respect to the proximal segment, the distal hub is no longer coaxially aligned with the longitudinal axis of the spring element. ### Claim 17 (depends on 9) The catheter of claim 9, wherein the distal segment includes an ablation element configured to deliver ablation therapy. ### Claim 18 (depends on 9) The catheter of claim 9, wherein the distal segment includes a distal hub, and the plurality of sensing elements include a rod connected to the distal hub.