What Controlled Desaturation Studies Reveal About Device Accuracy—and Why They Matter

Accurate oxygen saturation measurement is foundational for modern physiological monitoring, especially for developers of pulse oximeters, wearables, and multiparameter platforms. Yet many devices fail to achieve regulatory expectations because their performance is never tested across the full range of oxygen saturation levels humans experience. 

Controlled desaturation studies fill this gap, ensuring claims reflect real-world performance. These studies intentionally and safely lower volunteer participant’s oxygen levels under strict oversight to generate precise reference data. For medical device developers navigating FDA submissions, CE mark pathways, or standards like ISO 80601-2-61, controlled desaturation is a critical component of a medical device validation strategy. 

What Is a Controlled Desaturation Study? 

A controlled desaturation study is a clinical research study conducted in a hypoxia lab where volunteers breathe precisely mixed gas compositions to reach specified oxygen saturation plateaus. Throughout the session, investigators collect synchronized device data and reference measurements—arterial blood samples—allowing developers to quantify device accuracy across a full desaturation range of 100-70% arterial oxygen saturation. 

PRL’s hypoxia lab supports this work with calibrated gas-delivery systems, continuous safety monitoring, and an experienced clinical team. Our principal investigator has performed more than 3,000 arterial line placements in the last two years, enabling gold standard reference SaO₂ data collection for pulse oximetry studies. 

Why Developers Use Controlled Desaturation 

1. Regulatory-Grade Accuracy Evaluation 

Accurate oxygen saturation measurement is essential for pulse oximeters, wearables, and multiparameter platforms. Regulators require evidence of device performance below 90% SpO₂, where critical clinical decisions are made. Controlled desaturation enables: 

• Data collection over a full range of SaO₂ values 

• Time-aligned pairing of device readings with the reference co-oximetry for trustworthy comparisons 

• Assessment of accuracy, bias, and precision  

• Validation for FDA submissions and CE mark applications 

• Data that aligns with study expectations in ISO 14155, good clinical practice (GCP) requirements, and the accuracy frameworks used in pulse oximetry testing 

  
  

2. Inclusive Participant Recruitment and Skin Tone Representation 

Skin tone may affect light-based technologies, making diversity essential in pulse oximetry studies. PRL uses the Monk scale to recruit across broad skin tone categories, aligning recruitment with current FDA guidance, relevant ISO expectations, and recommendations from the Open Oximetry Project to support equitable device performance and transparent labeling. 

3. Stronger Pulse Oximetry and Wearable Performance Claims 

Wearable and sensor developers rely on controlled desaturation to evaluate: 

• Algorithm performance against laboratory-grade reference data 

• Consistency assessments across sites, sensors, and software versions 

• Motion and perfusion challenges, if requested 

• Non-disparate performance evaluation across skin tones and Individual Typology Angles (ITA) 

• Clear labeling inputs (accuracy range, methods, test conditions) mapped to ISO 80601-2-61 and GCP 

  
  

These studies also support CRO risk mitigation by reducing accuracy-related FDA submission delays. 

How Controlled Desaturation Studies Work 

Every controlled desaturation study begins with a regulator-aligned protocol. PRL collaborates with sponsors to define endpoints, sampling, safety, and analysis consistent with ISO 80601-2-61: 

Study design and protocol development 

• Informed consent and IRB considerations 

• Sampling frequency and blood-draw timing 

• Target plateau levels (e.g., across the clinical range) 

• Device placement and configuration 

• Skin-tone distribution and documentation 

  
  

During the study in PRL’s Hypoxia Lab: 

• Participants breathe controlled nitrogen/oxygen mixtures to gradually lower SpO₂. 

• Arterial blood samples analyzed using CO-oximetry provide reference SaO₂. 

• All data streams—from investigational devices to reference monitors—are time-aligned for analysis. 

  
  

PRL’s emphasis on protocol alignment and transparent CRO operations delivers robust, audit-ready datasets and submission-ready accuracy metrics. 

Conclusion: A Critical Tool for High-Quality Physiological Monitoring 

Controlled desaturation in healthy volunteers creates safe, repeatable oxygen plateaus across the clinically relevant range so devices can be compared to laboratory co-oximetry under tightly time-aligned sampling.  Defined in ISO 80601-2-61, this approach produces traceable, submission-ready accuracy data and clear inputs for labeling. It is a cornerstone of scientifically credible, regulator-ready device validation. 

For teams building pulse oximeters, wearables, or physiological sensing platforms, it provides the accuracy dataset necessary to meet global regulatory expectations while ensuring inclusivity and technical rigor. 

Ready to plan a controlled desaturation or pulse oximetry study?  PRL partners with medical and wearable device developers to design and execute studies that support FDA and CE mark submissions with confidence. Contact us today.

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