How pulse oximeters measure your blood oxygen levels

If you've had a respiratory illness and you can't get to the doctor, then measuring your blood oxygen levels can be vital. This device a pulse oximeter, can be used to tell whether you're just short of breath or whether you need to get to an emergency room. So how exactly just one of these work and most importantly, what can you do if you can't get your hands on a pulse oximeter. [MUSIC] Pulse oximeter measures the oxygen saturation of your blood. This rating known as SPO2 helps doctors tell how effectively your lungs are getting oxygen into the body. Then how well your heart is pumping that oxygenated blood around your body, you're probably hearing a lot about pulse oximeter as during the COVID-19 pandemic. And that's because of what COVID does to the lungs. Some of it can just be a sense of tightness in the chest. So there could actually be difficulty getting oxygen into the bloodstream, pulse ox, pulse oximeter. Can give you a little bit of information about how that oxygen exchange is working. Even if somebody doesn't feel bad or look bad, you can still see that they're having some difficulty getting oxygen into their blood with a pulse ox. Summer. In a hospital pulse oximetry can help doctors identify which patients might need to go to the ICU and maybe even go on to a ventilator. But a lot of people are writing out COVID-19 symptoms at home. So an at home pulse oximeter can help them track those symptoms. Now, we bought this device a couple of weeks ago on Amazon, it was about $40. It measures heart rate and pulse of symmetry and it doesn't even need to draw blood,it just does it with light. Pulse of symmetry consists of an infrared light meter and infrared light sensor and it passes infrared light through your finger. And the way this works is that, the more oxygenated hemoglobin that you have in your blood means more infrared light will pass, will be absorbed and more red light will be allowed to pass through. But more deoxygenated hemoglobin in the haven is the opposite. So it will allow more infrared light to pass through, and it will absorb more red light. Now these devices do have their limitations because they use light they work better on people with pale skin. People with darker skin might get a false reading Same goes if you're wearing nail polish that might give you a false reading. And then there are a lot of factors that can also affect your measurement. Smokers might get an artificially high reading whereas people who live at high elevations could get a lower reading. But generally speaking if you're healthy, you're looking for number between 94 and 100. These devices are great but because of the pandemic They are getting hard to find, they are selling out online. So if you're feeling short of breath and you're feeling really sick, and you can't get your hands on a pulse oximeter, what should you do? Well, this is where phones and wearables come into the picture. [MUSIC] In recent years, SpO2 tracking has started showing up on more devices. Older models of Samsung phones, up to the Note 9 and the S10, measure it through the Samsung Health app. Fitbit lets you track fluctuations in blood oxygen, and Garmin offers spot measurements as well as all-day tracking. But these companies are really careful to promote it more as a wellness feature rather than a precise medical measurement. Samsung measures blood oxygen in the stress tracker in the Samsung Health app. While Garmin says its pulse oximetry is designed for recreational use, rather than medical use, when I use my Samsung Note nine, I got a measurement of 97. But when I use my FDA approved pulse oximeter I got a measurement of 99. So why the different reading? Well, an actual pulse oximeter has two sensors. It sends light from one side and then receives it on the other side. My phone and other Other wearables, they only have one sensor so they're sending and receiving the light all on one side, so it's less accurate. phones and wearables are good for tracking your pulse oximetry in a general wellness sense, but they're definitely not the kind of device you want to use. If you want an accurate medical rating, and FDA approved pulse oximeter like this one is a far better option. If you need an accurate medical rating, but if you're buying online watch app, according to Dr. David Petrino from Mount Sinai in New York, manufactured to FDA compliance is not the same as FDA approved. If you're buying on Amazon it will explicitly say if it's FDA approved. You can also look for the CE mark on products out of Europe All TGA approval on products from Australia. These are similar to FDA approval and sign that you're buying a regulated device. But if it's late at night and you're feeling really short of breath, and you don't have a pulse on Oximeter, can you still use your phone or your wearable? Well, the answer is if it's not FDA approved, then you're not really getting an accurate rating. Or play with them using that to be like, Listen, I'm still reaching out to urgent care. And this is what my devices say. But I think that we should Really make people aware that if you're not getting an FDA approved device. Then there's a really good chance that that device is not giving you correct information. When it comes to lung health, there are a few signs you can look for without resorting to a device. Are you breathing a lot faster than you normally would? Is it hard for you to finish a sentence for example You finding it tough to keep up with the conversation or maintain concentration is there blueness around your lips. These are all signs that there's not enough oxygen in your blood. Ultimately, you know your own body and you should never put off seeking medical advice just because your phone didn't tell you to