Respiratory equipment — Particular requirements for basic safety and essential performance of infant cardiorespiratory monitors

Background and Purpose of the Standard

ISO 18778:2022 is the second edition of the international standard for infant cardiopulmonary monitors, replacing the first edition in 2005. This standard sets forth specific requirements for the basic safety and performance of infant cardiopulmonary monitors, aiming to ensure the safe and effective use of the device in home healthcare settings. The standard was developed based on the clinical need for monitoring infant apnea, particularly to prevent the risk of sudden infant death syndrome (SIDS). With technological advancements, the new version of the standard has expanded its scope to cover the impact of accessories on safety performance and is fully harmonized with IEC 60601-1, third edition.

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Scope and Key Terms

This standard applies to:

Infant cardiopulmonary monitors used in home medical environments;

Used by non-professionals (laypersons);

Monitoring cardiopulmonary parameters in children under 3 years old who are sleeping or resting;

Requires transport capability.

Key terms include: apnea (breathing cessation lasting ≥10 seconds), basic performance (such as generating apnea alarm, sensor malfunction alarm, etc.), internal power supply (at least 8 hours of battery life), etc.

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Basic Performance and Safety Requirements

The standard specifies several basic performance requirements, including:

Direct respiratory monitoring (detection of central or obstructive sleep apnea by at least one method);

Indirect monitoring of apnea activity (such as heart rate or blood oxygen saturation);

Alarm system requirements (apnea alarm delay ≤10 seconds, sensor fault alarm delay ≤20 seconds);

Automatic switching to internal power supply in case of power interruption.

Safety aspects involve electrical, mechanical, radiation, and electromagnetic compatibility, with a particular requirement that the equipment should not simultaneously lose respiratory and heart rate monitoring functions under single-fault conditions.

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Comparison of Standard Framework Changes

Dimensions	ISO 18778:2005	ISO 18778:2022
Scope of Application	Only for infant apnea monitors	Extended to infant cardiopulmonary monitors and accessories
Basic Performance	Not explicitly defined	Three basic performance characteristics are explicitly listed (apnea alarm, sensor failure alarm, internal power remaining time alarm)
Alarm System	Basic Requirements	Add alarm log (≥1000 events), alarm pause time ≤120 seconds, disable "alarm off" function
Power Requirements	Internal power supply not required	Requires internal power supply for at least 8 hours, automatic switching, and multi-level remaining power alarm
Electromagnetic Compatibility	Refers to IEC 60601-1-2 (old version)	Refers to IEC 60601-1-2:2014+AMD1:2020, adding specific degradation guidelines
Clinical Evaluation	No specific requirements	Requires clinical research (compliant with ISO 14155)

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Core Clause Interpretation: Alarm System and Power Management

The alarm system of an infant cardiopulmonary monitor is crucial for ensuring patient safety. The 2022 standard requires:

The apnea alarm limit can be adjusted by the responsible organization within 5-20 seconds, but cannot be directly adjusted by a lay operator;

The sound pressure level of high-priority alarms is between 70-90 dBA and can be automatically adjusted;

The alarm log records at least 1000 events, including power switching, alarm setting changes, etc.

Regarding power management:

The internal power supply must support at least 8 hours of continuous operation;

When the mains power is abnormal, it automatically switches to the internal power supply within 5 seconds;

Provide alarm reminders for 30 minutes and 5 minutes of remaining power.

These requirements ensure that even non-professionals can respond to alarms promptly in a home environment and avoid monitoring interruptions due to power depletion.

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Implementation Recommendations

When implementing this standard, manufacturers should focus on the following points:

Risk Management: Conduct risk management in accordance with ISO 14971, especially maintaining the independence of respiratory and heart rate monitoring under single-failure conditions;

Usability Engineering: Conduct usability testing in accordance with IEC 62366-1, clearly defining the division of tasks between lay and professional operators;

Clinical Research: For new equipment or major modifications, multi-center clinical studies should be conducted in accordance with ISO 14155 to verify the sensitivity and positive predictive value of sleep apnea detection;

Documentation Preparation: Provide instruction manuals for both lay and medical personnel, including startup testing, power supply testing, alarm testing, etc.;

Electromagnetic Compatibility: Ensure that basic performance is maintained under electromagnetic interference in a home environment, especially the sleep apnea detection function.

In addition, it is recommended that manufacturers communicate with testing laboratories in advance, especially regarding the handling of measurement uncertainty (test error should not exceed 30% of the claimed tolerance).

Technology Evolution Analysis

From the 2005 version to the 2022 version, the standard reflects the following technological evolution directions:

Intelligentization: Introducing intelligent alarm systems that can adjust alarm priorities or suppress alarms based on additional information;
• Datafication: Requires the provision of data interfaces (such as electronic health record connections) to facilitate remote monitoring and data analysis;
• Humanization: Focuses on the needs of lay operators, providing preset alarm limits, automatic alarm volume adjustment, and transport fixation devices;
• Rigorousness: Clarifies clinical research requirements and alarm log functions to improve the evidence-based level of equipment.
  These changes reflect a shift in medical devices from "safe and usable" to "intelligent, traceable, and clinically effective," and set a benchmark for future home medical device standards.