Hi. Here's my view if people are considering parting with their cash for a pulse monitor and don't know which way to jump. There are only two logical variables when buying a heart rate monitor for ME POTS, in my view:
1)
Buy a heart rate monitor for your own inquisitive investigative reasons, the certification doesn't matter as long as it's reasonably accurate in taking your pulse. I'd say for pulse monitoring of staying in a 'zone' this is fine.
2)
Buy a medically certified monitor in which you can record (USB/Bluetooth) the results, save the data, and keep the data in order to have medical proof you have something wrong with you if no one believes you. (You may need this level of certification if you are a frequent flyer to ER and keep bouncing out as no one has diagnosed you with a heart arrhythmia/POTS and you're desperate for evidence). NB: Always make sure your doctor know you have arrhythmias first and request an ECG/24hr ECG (in writing if need be), before resorting to playing doctor yourself or spending a fortune on high grade medical devices.
Having said that....
My latest monitor was around $1200 (with propriety software), hence they rip you off. However, it helped 'prove' I have hypoxia events which I could print off and send to people as 'proof'. If I'd got a $200 Amazon special, a disbelieving doctor can always say ''the machine didn't work'' or ''it's cheap''. With health equipment, when possible always invest the best quality you can within your budget and that way, if you look after it, the device tends to last for years and when you need it in an emergency (BP, Spo2, Pulse) you know what you're seeing is accurate.
The last point that is important to remember when using a finger spO2 sensor, is if you have cold hands/poor circulation/anxiety/low blood sugar basically anything that activates your sympathetic nervous system, then the monitor can sometimes not work well, and thus you will hear this time and time again in ER that they don't believe you! Educate them if necessary that self aborting heart arrythmias (paroxsymal attacks) are common in autonomic dysfunction, then educate them further by printing off you trip to ER when you were clambering out the moon roof in panic.
That's why I bought a very expensive monitor, as an investment, however, if you don't need this and you want simple monitoring and don't spend your life racing down roads with chest pain and racing pulse, I'd get a cheap one which I'm sure will do it's job at simple pulse monitoring.
.