ISO 80601-2-85:2021

Overview

ISO 80601-2-85:2021 - developed jointly with IEC - defines particular requirements for the basic safety and essential performance of cerebral tissue oximeter equipment. The standard covers non‑invasive devices that use multi‑wavelength light (continuous, frequency‑domain or time‑domain technologies) to derive a quantitative measure of regional cerebral oxygen saturation (StO2) from tissue sampled under a probe attached to the head. It applies to complete medical electrical (ME) equipment, monitors, probes and probe cable extenders used in hospital and out‑of‑hospital settings (e.g., ambulances, air transport), and includes remanufactured devices. Devices or methods outside the scope-such as invasive oximeters, laboratory blood‑sample oximeters, dissolved oxygen measurement, pulse oximeters (SpO2) and functional NIRS-are explicitly excluded.

Key technical topics and requirements

• Essential performance and safety: Requirements for basic electrical safety, mechanical construction, thermal limits and protection against hazardous outputs specific to cerebral tissue oximeters.
• StO2 accuracy and validation: Dedicated clauses and informative annexes (e.g., on data collection, analysis and human subject evaluation) describe methods to determine and document accuracy of cerebral oxygen saturation measurements.
• Probe and accessory requirements: Labelling, marking, IP classification, probe fault detection and probe cable extender requirements tailored to head‑mounted probes.
• Environmental and use conditions: Design and testing for hospital and emergency transport environments, including robustness to shock, vibration and short power interruptions.
• Alarms, usability and EMC: Requirements for alarm priority/presets, usability testing, electromagnetic compatibility (EMC) and connection to clinical information systems.
• Remanufacturing and documentation: Guidance for reconditioned/remanufactured devices and mandatory manufacturer information and instructions for use.

Practical applications and who uses this standard

• Medical device manufacturers designing and certifying cerebral tissue oximeters (near‑infrared spectroscopy, NIRS) and their probes.
• Regulatory and compliance teams ensuring CE/market access and conformity to safety/performance requirements.
• Clinical engineers and procurement staff evaluating device safety, accuracy (StO2) and suitability for transport or bedside monitoring.
• Test laboratories performing performance verification, EMC, alarm and environmental testing.
• Risk managers and usability specialists documenting alarm behaviour, labelling and instructions for use.

Related standards

• ISO 80601‑2‑71 - requirements for functional near‑infrared spectroscopy (fNIRS) equipment (performance measuring path‑length‑dependent haemoglobin change).
• ISO 80601‑2‑61 - requirements for pulse oximeter equipment (SpO2).
• General IEC/ISO medical electrical equipment collateral standards and normative references cited in ISO 80601‑2‑85 (see annexes for cross‑references and rationale).

Keywords: ISO 80601‑2‑85, cerebral tissue oximeter, StO2 accuracy, near infrared spectroscopy, medical electrical equipment, probe, NIRS, device standards.