IEC 60601-2-33:2022/ISH1:2023 1 @IEC2023 INTERNATIONAL ELECTROTECHNICAL COMMISSION IEC60601-2-33 Edition4.02022-08 MEDICAL ELECTRICAL EQUIPMENT. Part 2-33: Particular requirements for the basic safety and essential performance of magnetic resonance equipment for medical diagnosis INTERPRETATION SHEET 1 This interpretation sheet has been prepared by subcommittee 62B: Medical imaging equipment. software, and systems, of IEC technical committee 62: Medical equipment, software, and systems. The text of this interpretation sheet is based on the following documents: DISH Report on voting 62B/1315/DISH 62B/1319/RVDISH Full information on the voting for the approval of this interpretation sheet can be found in the report on voting indicated in the above table. Definition 201.3.214 (EFFECTIVE STIMULUS DURATION ts,eff) The definition is clarified by the following: a) It is important to consider that the magnetic field gradient displayed in Figure 201.101 can be realized by simultaneous activation of multiple GRADIENT UNITs. b) The concept of ts,eff applies both to cardiac stimulation and peripheral nerve stimulation. c) The appropriate timescale for evaluating the duration of monotonic increase or decrease of IEC 60601-2-33:2022-08/ISH1:2023-05(en) the GRADIENT oUTPUT is in the order of the chronaxie. When a discrete time-segment based approach is used for numerical evaluation, one or more discrete time segments deviating unintentional misinterpretation of monotonicity. ICS11.040.55 -2－ IEC60601-2-33:2022/ISH1:2023 IEC2023 Definition 201.3.219 (HEAD SAR) Note 1 to entry is clarified as follows: Extent of the head as provided in the note to entry represents a common understanding of medical professionals. Variation in assessment volume for HEAD SAR is acceptable for use by the MR MANUFAcTURER when implementing IEC 60601-2-33. For example, these volumes could be(tilted)axialdemarcationsof cervicalvertebrae C3,C5,or C7.