Drugdu.com expert's response:

 

The inspection of active medical devices should focus on their safety, effectiveness, and compliance, requiring a systematic evaluation that integrates product characteristics, usage scenarios, and regulatory requirements. Below are the core inspection points:

I. Electrical Safety and Protection

Insulation Performance

Test the insulation resistance between live parts and accessible components to ensure effective current isolation under both normal and fault conditions, preventing electric shock.

Verify the durability of insulating materials under high-temperature and humid conditions to avoid insulation failure due to aging.

Leakage Current Control

Detect current flowing from live parts to non-live parts (e.g., housing) during operation, ensuring it remains below the human safety threshold (typically ≤0.5mA).

Simulate single-point failures (e.g., insulation damage) to verify that the protective grounding system can safely divert leakage current to the ground.

Voltage Withstand Capability

Apply a test voltage higher than the rated voltage (e.g., 1.5 times the operating voltage) for 1 minute to check for insulation breakdown, ensuring the device can withstand transient overvoltages.

Grounding Reliability

Measure the resistance between the protective grounding terminal and accessible metal parts to ensure grounding resistance ≤0.1Ω, enabling rapid fault current conduction.

II. Electromagnetic Compatibility (EMC)

Emission Control

Radiated Emissions (RE): Test electromagnetic interference radiated through space, ensuring compliance with international standards (e.g., CISPR 11) to avoid disrupting other medical devices or communication systems.

Conducted Emissions (CE): Detect interference conducted through power or signal lines to prevent grid contamination or impact on connected devices.

Immunity Performance

Electrostatic Discharge (ESD): Simulate static electricity from human or device contact to verify normal operation under ±8kV contact discharge or ±15kV air discharge.

Radiated RF Immunity (RS): Test the device’s resistance to interference in RF fields (10V/m to 30V/m) to ensure functionality is unaffected by wireless devices (e.g., mobile phones).

Electrical Fast Transients (EFT): Simulate transient pulse interference on power lines to verify the device’s ability to withstand ±2kV to ±4kV pulses.

III. Mechanical and Physical Performance

Structural Stability

Inspect the strength of housing, brackets, connectors, and other components to ensure they withstand mechanical stresses (e.g., vibration, impact) during transportation, installation, and use.

Verify the durability of moving parts (e.g., adjustable brackets, rotating joints) to prevent loosening or breakage from frequent operation.

Environmental Adaptability

Temperature and Humidity: Simulate performance under extreme temperatures (e.g., -20°C to 55°C) and high humidity (e.g., 95%RH) to ensure normal operation of circuits and sensors.

Air Pressure and Altitude: Test sealing and functional stability under low or high pressure for devices used at high altitudes or underwater.

Dust and Water Resistance: Validate protection against solid particles and liquids per IP ratings (e.g., IP54, IP67) to prevent internal component damage.

IV. Biocompatibility and Material Safety

Contact Component Evaluation

Conduct cytotoxicity, sensitization, and genotoxicity tests on parts in direct contact with the human body (e.g., electrodes, catheters, housing) to ensure no biological hazards.

Assess chemical stability after long-term use or sterilization to prevent the release of harmful substances (e.g., plasticizers, heavy metals).

Cleaning and Sterilization Compatibility

Verify tolerance to clinical sterilization methods (e.g., alcohol wipes, ethylene oxide sterilization, autoclaving) to ensure performance integrity and residue-free results.

V. Core Functionality and Performance Verification

Functional Accuracy

Validate core parameters (e.g., heart rate monitoring precision, defibrillation energy output, imaging resolution) against design requirements based on the device’s purpose (e.g., monitoring, treatment, diagnosis).

Test performance stability under boundary conditions (e.g., minimum/maximum operating voltage, load).

Alarm and Safety Mechanisms

Check alarm functionality during abnormalities (e.g., low battery, sensor detachment, parameter exceedance) to ensure clear signals (e.g., sound, light, vibration).

Verify timely activation of automatic protections (e.g., overcurrent protection, temperature control) to prevent device damage or patient harm.

VI. Software and Cybersecurity

Software Functionality Testing

Validate interface logic, data recording/transmission, and algorithm accuracy (e.g., ECG analysis, dose calculation) to ensure no functional defects or logical errors.

Test fault tolerance under abnormal inputs (e.g., invalid characters, out-of-range data) to prevent crashes or data loss.

Cybersecurity Protection

For networked devices, assess data encryption strength (e.g., AES-256), user authentication (e.g., two-factor authentication), and access control to prevent unauthorized access or data breaches.

Simulate cyberattacks (e.g., DDoS, man-in-the-middle) to verify resistance to malicious intrusion and functional continuity.

VII. Labeling and Instruction Compliance

Label Clarity

Ensure labels include model, serial number, manufacturing date, electrical parameters (e.g., voltage, frequency), and warning symbols (e.g., electric shock risk, laser radiation) per international standards (e.g., YY/T 0466.1).

Instruction Completeness

Verify that instructions cover installation, operation, maintenance, troubleshooting, and safety precautions (e.g., prohibition of use in wet environments, avoidance of metal contact).

VIII. Risk Management and Clinical Evaluation

Risk Analysis

Identify potential hazards (e.g., electrical failures, mechanical injuries, software errors) across the device lifecycle per ISO 14971, assess risk levels, and implement controls (e.g., redundant design, warnings).

Clinical Data Support

Provide clinical validation reports to demonstrate safety and effectiveness in real-world use, particularly for high-risk products (e.g., implantable devices, AI-assisted diagnostic software).

By addressing these inspection points, the quality and compliance of active medical devices can be comprehensively evaluated, ensuring their safe and effective use in clinical settings.

By editor