1、Designation:F221306(Reapproved 2011)Standard Test Method forMeasurement of Magnetically Induced Torque on MedicalDevices in the Magnetic Resonance Environment1This standard is issued under the fixed designation F2213;the number immediately following the designation indicates the year oforiginal adop
2、tion 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 covers the measurement of the mag-netically induced torque pro
3、duced by the static magnetic fieldin the magnetic resonance environment on medical devices andthe comparison of that torque to the equivalent torque appliedby the gravitational force to the implant.1.2 This test method does not address other possible safetyissues which include but are not limited to
4、 issues of magneti-cally induced force due to spatial gradients in the staticmagnetic field,RF heating,induced heating,acoustic noise,interaction among devices,and the functionality of the deviceand the MR system.1.3 The torque considered here is the magneto-static torquedue to the interaction of th
5、e MRI static magnetic field with themagnetization in the implant.The dynamic torque due tointeraction of the static field with eddy currents induced in arotating device is not addressed in this test method.Currents inlead wires may induce a torque as well.1.4 The sensitivity of the torque measuremen
6、t apparatusmust be greater than110the“gravity torque,”the product of thedevices maximum linear dimension and its weight.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thes
7、afety 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:2F2052 Test Method for Measurement
8、 of Magnetically In-duced Displacement Force on Medical Devices in theMagnetic Resonance EnvironmentF2119 Test Method for Evaluation of MR Image Artifactsfrom Passive ImplantsF2182 Test Method for Measurement of Radio FrequencyInduced Heating On or Near Passive Implants DuringMagnetic Resonance Imag
9、ingF2503 Practice for Marking Medical Devices and OtherItems for Safety in the Magnetic Resonance Environment2.2 Other Standards:IEC 60601-2-33 Ed.2.0 Medical Electrical EquipmentPart 2:Particular Requirements for the Safety of MagneticResonance Equipment for Medical Diagnosis,20023ISO 13485:2003(E)
10、Medical DevicesQuality Manage-ment SystemsRequirements for Regulatory Purposes,definition 3.733.Terminology3.1 DefinitionsFor the purposes of this test method,thedefinitions in 3.1.1 3.1.18 shall apply:3.1.1 diamagnetic materiala material whose relative per-meability is less than unity.3.1.2 ferroma
11、gnetic materiala material whose magneticmoments are ordered and parallel producing magnetization inone direction.3.1.3 magnetic induction or magnetic flux density(B inT)that magnetic vector quantity which at any point in amagnetic field is measured either by the mechanical force1This test method is
12、under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved Oct.1,2011.Published October 2011.Originallyapproved in 2002.Last previous edition approved in 2006 as F22
13、13 06.DOI:10.1520/F2213-06R11.2For 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.3Available from American National St
14、andards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 experienced by an element of electric current at the point,or bythe electromotive force induced in an ele
15、mentary loop duringany change in flux linkages with the loop at the point.Themagnetic induction is frequently referred to as the magneticfield.B0is the static field in an MR system.Plain type indicatesa scalar(for example,B)and bold type indicates a vector(forexample,B).3.1.4 magnetic field strength
16、(H in A/m)strength of theapplied magnetic field.3.1.5 magnetic resonance(MR)resonant absorption ofelectromagnetic energy by an ensemble of atomic particlesituated in a magnetic field.3.1.6 magnetic resonance diagnostic devicea device in-tended for general diagnostic use to present images whichreflect the spatial distribution or magnetic resonance spectra,orboth,which reflect frequency and distribution of nuclei exhib-iting nuclear magnetic resonance.Other physical parametersderived from the imag
