Pulse Oximeter Technical Specifications and Purchasing Guide

Clinical Summary: Pulse oximeters are non-invasive devices measuring arterial oxygen saturation (SpO2) and pulse rate. This guide covers technical specifications, accuracy standards, and selection criteria for clinical, emergency, and home-use applications.

Technology Overview

Pulse oximetry utilizes spectrophotometric principles, measuring light absorption at two wavelengths (typically 660nm red and 940nm infrared) to calculate oxygen saturation based on differences between oxygenated and deoxygenated hemoglobin.

Device Types

• Fingertip Oximeters: Portable, battery-operated devices for spot checks
• Handheld Oximeters: Clinical-grade with separate sensor probes
• Tabletop Monitors: Continuous monitoring with trending capabilities
• Wearable Devices: Continuous monitoring for sleep studies and fitness

Technical Specifications

Measurement Range and Accuracy

Parameter	Range	Accuracy (ARMS)
SpO2 (70-100%)	0-100%	± 2-3%
SpO2 (below 70%)	0-69%	Unspecified
Pulse Rate	25-250 bpm	± 2 bpm or 2%
Perfusion Index	0.02-20%	Varies by model

Performance Under Challenging Conditions

• Motion Artifact: Advanced signal processing for readings during patient movement
• Low Perfusion: Performance at perfusion indices as low as 0.02%
• Skin Pigmentation: FDA guidance requires testing across diverse skin tones
• Ambient Light: Rejection of interference from room lighting

FDA Regulatory Requirements

Pulse oximeters are FDA Class II medical devices requiring 510(k) premarket notification. Key regulatory considerations:

• ISO 80601-2-61: Particular requirements for pulse oximeter equipment
• FDA Guidance: Pulse Oximeters – Premarket Notification Submissions (2013)
• Clinical Testing: Controlled desaturation studies in healthy volunteers
• Labeling: Clear indication of accuracy specifications and limitations

Sensor Types and Compatibility

Reusable Sensors

Sensor Type	Patient Population	Application Site
Adult Finger Clip	> 30 kg	Index/Middle finger
Pediatric Finger Clip	10-50 kg	Index/Middle finger
Adult Ear Clip	> 30 kg	Earlobe
Infant Wrap	< 3 kg	Foot/Hand

Disposable Sensors

• Adhesive Sensors: Single-patient use, reduces cross-contamination risk
• Neonatal Sensors: Designed for NICU monitoring
• Extended Wear: Multi-day monitoring capability

Clinical Considerations

Factors Affecting Accuracy

• Dyshemoglobinemias: Carboxyhemoglobin, methemoglobin affect readings
• Anemia: Severe anemia may affect accuracy at low saturations
• Nail Polish: Dark colors may interfere with light transmission
• Poor Perfusion: Shock, hypothermia, vasoconstriction
• Venous Pulsation: Right heart failure, tricuspid regurgitation

Selection Criteria by Setting

Hospital/Clinical

• FDA-cleared with documented accuracy specifications
• Motion-tolerant technology
• Multiple sensor options for different patient populations
• Alarm capabilities with adjustable limits
• EMR/EHR integration

Home/Consumer

• FDA-cleared OTC device
• Simple operation and display
• Clear accuracy specifications in labeling
• Understanding of limitations for dark skin tones

Related Resources

• Respiratory Therapy Equipment Standards
• Standards Hub – FDA regulatory requirements
• Documentation Hub – Technical specifications library