Organic blood-oxygen sensor can be stuck on like a Band-Aid
Amazon.com: CMI Health Rechargeable Pulse Oximeter - Adult Finger Sensor for Continuous Monitoring & Spot-Checking - Adjustable Alarm for Pulse Rate and SpO2 Levels - Carry Case, AC Adapter Included : Health
Pulse Oximeter Repair Sensor Off Error || Oximeter Not Working || Oximeter Real Or Fake - YouTube
How Do Pulse Oximeters Work? A Complete Guide - Infinium Medical