MZ/T 210-2024
Electrophysiological testing methods before cochlear implantation (English Version)

Standard No.

MZ/T 210-2024

Language

Chinese, Available in English version

Release Date

2024

Published By

Professional Standard - Civil Administration  CN  /  MZ

Latest

MZ/T 210-2024

Introduction

Analysis of standard technical framework

Test type	Recording site	Typical waveform	Clinical significance
ECAP	Spiral ganglion	N1-P1 complex wave	Assess the function of auditory nerve endings
EABR	Brainstem pathway	II-III-V waves	Detect the integrity of auditory brainstem conduction
EMLR	Primary auditory cortex	Pa-Nb complex wave	Assess central auditory processing ability

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Technical requirements for core equipment

The standard stipulates the use of 10-channel platinum electrodes (diameter 0.3mm) with a dedicated electrical stimulation system:

• Stimulation parameter range: pulse width 50-100μs, rate 23-37Hz, current 1-255CL (10.2-1750μA)
• Recording equipment requirements: evoked potential meter with high-frequency filter, impedance <5KΩ, gain 300K
• Synchronous trigger: 5V single-phase square wave signal trigger superposition, 850 times/minute average processing

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Standardized testing process

1. ECAP testing: Use No. 3/No. 5 electrode pairs, adjust the stimulation intensity with 5CL steps, and record the N1 wave threshold
2. EABR/EMLR testing: Determine the V wave/Pa wave threshold by 10CL step-down method, and the pulse width can be extended to 200μs
3. Data interpretation: Refer to the Gibson grading standard (grades 1-4), and focus on the III-V wave interval (2.08±0.24ms)

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Clinical implementation recommendations

According to the reference data in Appendix B of the standard:

• The normal ECAP threshold should be controlled in the range of 172.11±16.78CL
• The latency of EABR wave V exceeds 4.14±0.25ms, indicating conduction abnormality
• The Pa-Nb amplitude of EMLR <10.58μV needs to be combined with other examinations and evaluations

Special reminder: When the amplifier is saturated, the stimulation intensity should be immediately reduced by 20-30CL and retested.

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Analysis of standard evolution

This standard integrates 7 reference standards such as GB 9706.1 and YY 0989.7, and adds the following compared to the 2013 version of the Cochlear Implantation Guidelines:

• Quantitative current intensity conversion formula (μA=10.2*1.020462382CL-1)
• Specify the size requirements of the platinum sphere of the 10-channel electrode
• Standardize the synchronous detection process of the three evoked potentials

MZ/T 210-2024 Referenced Document

• GB 9706.1 Medical electrical equipment—Part 1: General requirements for basic safety and essential performance
• GB/T 14199 Electroacoustics.General specification for hearing aids
• GB/T 14396 Disease Classification and Codes
• GB/T 16886.1 Biological evaluation of medical devices—Part 1: Evaluation and testing within a risk management process
• GB/T 25102.100 Electroacoustics.Hearing aids.Part 0:Measurement of electroacoustical characteristics
• GB/T 25102.13 Electroacoustics.Hearing aids.Part 13:Electromagnetic compatibility (EMC)
• YY 0505 Medical electrical equipment.Part 1-2:General requirements for safety.Collateral standard:Electromagnetic compatibility.Requirements and tests
• YY 0989.7 Surgical implants Active implantable medical devices Part 7: Specific requirements for cochlear implant systems

MZ/T 210-2024 history

• 2024 MZ/T 210-2024 Electrophysiological testing methods before cochlear implantation

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