ASTM_F_1874_-_98_2011.pdf

Designation:F187498(Reapproved 2011)Standard Test Method forBend Testing of Needles Used in Surgical Sutures1This standard is issued under the fixed designation F1874;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method describes the procedure for bendtesting needles used for the placement of surgical sutures.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2F1840 Terminology for Surgical Suture Needles3.Terminology3.1 DefinitionsDefinitions of terms used in this testmethod are in accordance with Terminology F1840.3.2 Definitions of Terms Specific to This Standard:3.2.1 needle test gripping location,nfor test methods,theneedle will be clamped two-thirds of the distance back from thepoint of the needle.Since the needle will deform during thebend test,the needle test gripping location only applies to anunbent needle.3.2.2 test chord length,nthe straight line distance from thecenter of rotation of the needle in the test fixture to the initialpoint of contact with the bending platform or knife edge.4.Summary of Test Method4.1 Surgical needles are grasped approximately two-thirdsof the distance from the point of the needle,then bent againsta knife edge or platform.The force deflection data obtainedfrom the test will be used to calculate the yield bend momentand the maximum bend moment.4.2 The decision to use a knife edge or a platform for thebending surface will be determined by the equipment available.5.Significance and Use5.1 This test method provides a means of assessing the yieldmoment and maximum moment of a surgical needle.5.2 The needle is bent against a platform or knife edge,andit is bent at the approximate location where a pair of needleholders would grip it.This simulates the actual bending of aneedle while in surgical use.6.Apparatus6.1 Clamping FixtureA device to firmly clamp and rotatethe needle.6.2 Bending PlatformThe surface on which the curvedneedle will exert force during the test.The bending platformwill have its top surface located along the horizontal axis of thecenter of rotation of the clamping fixture.6.3 Knife EdgeThe knife edge will be placed parallel tothe centerline of rotation to provide a single point contact forreading the torque generated by the needle.6.4 Data Collection SystemThe data will be collected as afunction of rotational angle.6.5 Rotation SpeedThe clamping fixture must be rotatedat a continuous and constant speed.This speed will be less than30/s.7.Sampling7.1 A sample size of no less than five needles shall be used.8.Procedure(see Fig.1)8.1 Securely clamp the needle into the clamping fixture at aposition approximately two-thirds of the distance back fromthe tip of the needle.8.2 Rotate the clamping fixture forward until the needletouches the bending platform or knife edge.Continue rotatingthe clamping fixture through a sufficient angle to generate therequired data.While the needle is bending,collect the bendingforce data as a function of the bend angle.1This test method is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.33 on Medical/Surgical InstrumentsCurrent edition approved June 1,2011.Published July 2011.Originally approvedin 1998.Last previous edition approved in 2004 as F1874 98(2004).DOI:10.1520/F1874-98R11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 9.Calculation(see Fig.2)9.1 Data will be reported as a moment versus degrees ofrotation.Units will be reported.9.2 Yield Bend MomentUsing the graph obtained duringthe needle bend test,calculate the initial slope of the graph.Draw a line with the same slope through the 2 offset on thedegree axis.Read the bending moment at the point where the2 offset slope crosses the data line.This is the yield bendmoment.9.3 Yield Bend AngleRead the angle at the point where the2 offset slope line crosses the data line.FIG.1 Sample Bend TestsFIG.2 Bend Test Data CurveF1874 98(2011)2 9.4 Maximum Bend MomentThe maximum bend momentis the largest bending moment achieved by the needle duringthe bend test.10.Report10.1 Include the following information:10.1.1 Sample identification,test conditions,and apparatus.10.1.2 Test