# US 2008/0188934 A1 · Device For Ascertaining A Force-Displacement Characteristic Curve Of One Or More Ligaments, And Method Of Doing The Same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0188934 A1 - Document ID: US20080188934A1 - Status: Published application - Kind: A1 - Application number: 11/568,178 - Filed: 2005-04-20 - Published: 2008-08-07 - Earliest claimed: 2004-04-22 - Assignees: Smith & Nephew Orthopaedics AG - Inventors: Walter Moser; Peter Ritschl; Holger Broers - Web page: https://patentgrep.com/patent/US20080188934A1 ## CPC - A61B 17/025: {Joint distractors} - A61B 5/1076: {for measuring dimensions inside body cavities, e.g. using catheters (A61B3/1005 takes precedence)} - A61B 5/4533: {Ligaments} - A61B 2017/0268: {for the knee} - A61B 2090/061: {for measuring dimensions, e.g. length} - A61B 2090/064: {for measuring force, pressure or mechanical tension} - A61B 2090/3937: {Visible markers} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract An appliance (1) for tensioning ligaments, especially articular ligaments, of a human or animal body, having at least one handle (2), the or each handle (2) being in operative engagement with, in each case, a tensioning element (3) associated therewith, and with the or each handle (2) in each case a force indicator (4), which indicates a force exerted on a or each tensioning element (3) associated with the or each handle (2) on tensioning of one or more ligaments, and a displacement indicator (5), which indicates the excursion of the tensioning element (3) in question from a reference position, and with the or each force indicator (4) and/or with the or each displacement indicator (5) there is/are associated at least one marker (7A-7H), which is arranged to be detected without contact by a measurement value ascertainment system (20) associated with the appliance (1), and also a device (20), comprising the appliance (1), for ascertaining force-displacement characteristic curves of ligaments, and also a method of ascertaining them. ## Claims ### Claim at position 1 1-19. (canceled) ### Claim 20 An appliance for tensioning articular or other ligaments of a human or animal body, said appliance comprising: at least one handle; a tensioning element associated with said at least one handle, the handle being in operative engagement with the tensioning element; a force indicator associated with said at least one handle and configured to indicate a force exerted on the tensioning element upon tensioning of one or more ligaments; a displacement indicator associated with said at least one handle configured to indicate the displacement of the tensioning element from a reference position; and at least one marker associated with at least one of the force indicator and the displacement indicator, said at least one marker configured to be detected without contact by a measurement value ascertainment system associated with the appliance. ### Claim 21 (depends on 20) The appliance of claim 20, wherein the at least one marker comprises an optical element. ### Claim 22 (depends on 20) The appliance of claim 20, wherein the at least one marker comprises an element selected from the group consisting of magnetic elements, electromagnetic elements, and magnetic and electromagnetic elements. ### Claim 23 (depends on 20) The appliance of claim 20, wherein the tensioning element is actuatable using a force selected from the group consisting of a mechanical actuation force, an electromotive actuation force, a hydraulic actuation force, a pneumatic actuation force, and a hydro-pneumatic actuation force. ### Claim 24 (depends on 20) The appliance of claim 20, wherein the actuator associated with the tensioning element comprises a force-producing element for applying a force to the tensioning element, said force associated with the force-producing element being determinable via a measurement selected from the group consisting of a displacement difference, excursion from a reference position, and a displacement difference and excursion from a reference position. ### Claim 25 (depends on 24) The appliance of claim 24, wherein the force-producing element is a helical compression spring. ### Claim 26 (depends on 20) The appliance of claim 20, wherein the at least one marker is configured to determine an axis of orientation of the appliance. ### Claim 27 (depends on 26) The appliance of claim 26, wherein the at least one marker comprises elements selected from the group consisting of magnetic elements, electromagnetic elements, optical elements, magnetic and electromagnetic elements, magnetic and optical elements, and magnetic, electromagnetic and optical elements. ### Claim 28 (depends on 27) The appliance of claim 27, wherein the at least one marker configured to determine the axis of orientation of the appliance operates in a similar manner as at least one other marker associated with the appliance. ### Claim 29 (depends on 20) The appliance of claim 20, wherein at least one of the markers comprises a retro-reflective ball. ### Claim 30 A system for ascertaining a force-displacement relationship or a force-displacement characteristic curve of one or more animal or human articular or other ligaments, the system comprising: an appliance configured for tensioning ligaments; a marker detector configured for detecting at least one marker associated with the appliance; and a data evaluator configured for evaluating data ascertained from said detection of the at least one marker. ### Claim 31 (depends on 30) The system of claim 30, wherein the appliance comprises: at least one handle; a tensioning element associated with said at least one handle, the handle being in operative engagement with the associated tensioning element; a force indicator associated with said at least one handle and configured to indicate a force exerted on the tensioning element upon tensioning of one or more ligaments; and a displacement indicator associated with said at least one handle configured to indicate the displacement of the tensioning element from a reference position, wherein the at least one marker is associated with at least one of the force indicator and the displacement indicator, said at least one marker configured to be detected without contact with the marker detector and data evaluator. ### Claim 32 (depends on 30) The system of claim 30, further comprising a memory for storing data selected from the group consisting of ascertained data, evaluated data, reference data, specific data relating to the spatial location of the ligament apparatus being surveyed, and any combination thereof. ### Claim 33 (depends on 32) The system of claim 32, wherein said appliance and marker detector are configured to provide a force measurement of a force acting on a tensioning element of the appliance, a distance measurement selected from the group consisting of a displacement difference associated with the tensioning element and an excursion from a reference position associated with the tensioning element, and an orientation measurement of the axis of orientation of the appliance approximately simultaneously. ### Claim 34 (depends on 33) The system of claim 33, further comprising a unit configured to ascertain time-dependent changes in at least one of forces exerted on the tensioning element, displacement differences associated with the tensioning element, and excursions from a reference position, said displacement differences and excursions being associated with a force producing element associated with the tensioning element. ### Claim 35 (depends on 30) The system of claim 30, wherein the at least one marker comprises an optical marker and the marker detector comprises a stereo camera. ### Claim 36 A method of ascertaining a force-displacement relationship or a force-displacement characteristic curve of one or more animal or human articular or other ligaments, the method comprising: determining a force acting on a tensioning element; and determining at least one of a displacement difference and an excursion from a reference position associated with the tensioning element, wherein at least one of said determination of the force and determination of the displacement difference or excursion being carried out without contact with the device used to exert the force on the tensioning element. ### Claim 37 (depends on 36) The method of claim 36, further comprising determining an axis of orientation of an appliance for tensioning a ligament. ### Claim 38 (depends on 37) The method of claim 37, wherein said determination steps are carried out approximately simultaneously. ### Claim 39 (depends on 37) The method of claim 37, wherein at least one of the determination steps comprises using a measurement method selected from the group consisting of an optical method, a magnetic method, an electromagnetic method, and two or more of said measurement methods. ### Claim 40 (depends on 37) The method of claim 37, wherein the determination steps are carried out iteratively. ### Claim 41 (depends on 36) The method of claim 36, further comprising applying a constant force to the tensioning element and ascertaining the time-dependent excursion of the tensioning element from a reference position thereof. ### Claim 42 (depends on 36) The method of claim 36, further comprising ascertaining the time-dependent force applied to the tensioning element for a constant excursion of the tensioning element from a reference position thereof.