{"video_id":"Y4IJxO518mI","title":"Why You Shouldn't Trust Your Smart Ring","channel":"Techquickie","show":"Techquickie","published_at":"2026-04-08T18:47:55+00:00","duration_s":563,"segments":[{"start_s":0.0,"end_s":8.0,"text":"Like the thirsty cast members of The Bachelorette, Samsung Aura and, if","speaker":null,"is_sponsor":0},{"start_s":5.48,"end_s":13.0,"text":"rumors are correct, [music] Apple all want to put a ring on it. And why not?","speaker":null,"is_sponsor":0},{"start_s":11.4,"end_s":18.92,"text":"The promise of a smart ring is undeniably sexy. A screen-free titanium","speaker":null,"is_sponsor":0},{"start_s":16.24,"end_s":24.08,"text":"hoop that tracks your vitals 24/7. Who wouldn't want it? But, like a reality TV","speaker":null,"is_sponsor":0},{"start_s":21.72,"end_s":28.72,"text":"marriage, buying a smart ring is sometimes followed by regret. If you've","speaker":null,"is_sponsor":0},{"start_s":26.64,"end_s":32.16,"text":"ever wondered why your smart ring thinks you were napping while you were working","speaker":null,"is_sponsor":0},{"start_s":30.32,"end_s":36.52,"text":"and yet misses your PR at the gym, that's because, turns out, shrinking an","speaker":null,"is_sponsor":0},{"start_s":34.56,"end_s":40.76,"text":"entire lab's worth of equipment down to the size of a piece of jewelry requires","speaker":null,"is_sponsor":0},{"start_s":38.48,"end_s":45.0,"text":"some serious engineering compromises. Compromises that could be fat-fingering","speaker":null,"is_sponsor":0},{"start_s":43.0,"end_s":48.56,"text":"your biometric data. Let's break these devices down, starting with the main","speaker":null,"is_sponsor":0},{"start_s":46.88,"end_s":53.36,"text":"sensor. [music] PPG, or photoplethysmography, is a fancy name","speaker":null,"is_sponsor":0},{"start_s":50.8,"end_s":57.32,"text":"for shining light into your skin and measuring how much bounces back. In a","speaker":null,"is_sponsor":0},{"start_s":55.32,"end_s":61.8,"text":"hospital, they'll clip a sensor onto your fingertip, yield transmissive PPG.","speaker":null,"is_sponsor":0},{"start_s":60.08,"end_s":66.6,"text":"It's incredibly accurate because the signal is unobstructed. Smartwatches, on","speaker":null,"is_sponsor":0},{"start_s":64.16,"end_s":70.84,"text":"the other hand, use reflective PPG, where the sensor and the photodiode are","speaker":null,"is_sponsor":0},{"start_s":68.44,"end_s":74.8,"text":"on the same side. Fun fact, by the way, they use green light because your blood","speaker":null,"is_sponsor":0},{"start_s":72.84,"end_s":80.0,"text":"absorbs it like a sponge, providing a high-contrast signal. Depending on, you","speaker":null,"is_sponsor":0},{"start_s":77.32,"end_s":83.2,"text":"know, how far apart your photodiode is, if it's, say, on the curvature of a","speaker":null,"is_sponsor":0},{"start_s":81.4,"end_s":87.92,"text":"ring, you may actually kind of be between these modalities, where you're","speaker":null,"is_sponsor":0},{"start_s":85.0,"end_s":91.24,"text":"somewhat like in a transflective approach. You may see behavior of both","speaker":null,"is_sponsor":0},{"start_s":89.76,"end_s":96.2,"text":"like a reflective and a transmissive PPG. Smart rings can occupy a weird","speaker":null,"is_sponsor":0},{"start_s":93.8,"end_s":99.44,"text":"middle ground. Because the sensors wrap around your finger, light travels","speaker":null,"is_sponsor":0},{"start_s":97.8,"end_s":104.68,"text":"further through your skin than it would from a smart watch. This gives the ring","speaker":null,"is_sponsor":0},{"start_s":101.56,"end_s":106.88,"text":"a slight signal advantage, but it's one","speaker":null,"is_sponsor":0},{"start_s":104.68,"end_s":109.44,"text":"that unfortunately gets dragged down by the constraints that arise from its size","speaker":null,"is_sponsor":0},{"start_s":109.386,"end_s":115.48,"text":">> [music] >> and from its battery. >> The amount of light you need in order to","speaker":null,"is_sponsor":0},{"start_s":113.44,"end_s":118.4,"text":"measure an appreciable pulse is proportional also to the active area of","speaker":null,"is_sponsor":0},{"start_s":117.2,"end_s":122.72,"text":"the photodiode that you're using to sense it with. So, a bigger photodiode,","speaker":null,"is_sponsor":0},{"start_s":120.48,"end_s":127.44,"text":"a bigger sensor, means you can use less light, less current, in order to perform","speaker":null,"is_sponsor":0},{"start_s":125.28,"end_s":131.48,"text":"the same relative measurement. If you only just shrink the photodiode itself,","speaker":null,"is_sponsor":0},{"start_s":129.96,"end_s":135.12,"text":"you're going to be decreasing your your signal-to-noise ratio","speaker":null,"is_sponsor":0},{"start_s":133.36,"end_s":138.24,"text":"and have to, you know, boost your LED light in order to accommodate for that.","speaker":null,"is_sponsor":0},{"start_s":137.04,"end_s":142.32,"text":"You can think of it kind of like listening to a conversation in a crowded","speaker":null,"is_sponsor":0},{"start_s":140.04,"end_s":145.36,"text":"bar. A smartwatch stands next to a person with a large, directional","speaker":null,"is_sponsor":0},{"start_s":143.8,"end_s":148.72,"text":"microphone. A smart ring, on the other hand, is trying to hear them from across","speaker":null,"is_sponsor":0},{"start_s":147.32,"end_s":152.52,"text":"the room using a tiny little spy mic taped to their collar,","speaker":null,"is_sponsor":0},{"start_s":151.04,"end_s":157.856,"text":"which brings us to the battery. The Samsung Galaxy Watch Ultra packs 590","speaker":null,"is_sponsor":0},{"start_s":156.52,"end_s":163.84,"text":"mA hours. >> [music] >> The Galaxy Ring,","speaker":null,"is_sponsor":0},{"start_s":159.76,"end_s":166.72,"text":"17 to 22 and 1/2. And yet, the ring","speaker":null,"is_sponsor":0},{"start_s":163.84,"end_s":170.88,"text":"claims it lasts for up to 7 days. How? Well,","speaker":null,"is_sponsor":0},{"start_s":168.84,"end_s":174.12,"text":"because it doesn't. Both devices use duty cycling to extend their usable","speaker":null,"is_sponsor":0},{"start_s":172.6,"end_s":177.96,"text":"charge time, but because the watch has a larger battery, one intense session","speaker":null,"is_sponsor":0},{"start_s":176.16,"end_s":182.6,"text":"isn't going to drain it. The ring, on the other hand, has about","speaker":null,"is_sponsor":0},{"start_s":179.44,"end_s":184.32,"text":"the battery of a Cheerio. [music]","speaker":null,"is_sponsor":0},{"start_s":182.6,"end_s":187.2,"text":"They have also large dormant periods, where the ring simply is not measuring","speaker":null,"is_sponsor":0},{"start_s":186.12,"end_s":191.262,"text":"at all. And and so you can kind of think of it as like interlacing on top of","speaker":null,"is_sponsor":0},{"start_s":189.76,"end_s":195.52,"text":"interlacing, you know, in order to [music] make it so maybe you only measure the pulsations, measure the","speaker":null,"is_sponsor":0},{"start_s":193.96,"end_s":199.52,"text":"heart rate, pulse ox, you know, for a minute, you know, every 10, 15, 20","speaker":null,"is_sponsor":0},{"start_s":198.04,"end_s":203.76,"text":"minutes, for example, in order to to keep conserving uh power. [music] To put","speaker":null,"is_sponsor":0},{"start_s":201.76,"end_s":208.16,"text":"this in perspective, when the Franklin Research Lab built their own DIY smart","speaker":null,"is_sponsor":0},{"start_s":205.92,"end_s":212.96,"text":"ring, the battery gave out after about 4 to 6 hours of continuous use. So, if we","speaker":null,"is_sponsor":0},{"start_s":210.72,"end_s":217.96,"text":"take that as a baseline for true continuous tracking, to survive a full","speaker":null,"is_sponsor":0},{"start_s":215.32,"end_s":222.88,"text":"168-hour week of nonstop data collection, you'd need to wear 34 rings","speaker":null,"is_sponsor":0},{"start_s":220.48,"end_s":226.8,"text":"and swap them out like ammunition magazines. By Wednesday, you'd look more","speaker":null,"is_sponsor":0},{"start_s":224.96,"end_s":229.32,"text":"like the Divination instructor at Hogwarts than like a fitness enthusiast.","speaker":null,"is_sponsor":0},{"start_s":229.252,"end_s":234.492,"text":">> [music] >> The reason that smart ring bands can claim a week while Dr. Franklin gets","speaker":null,"is_sponsor":0},{"start_s":233.4,"end_s":239.56,"text":"only 5 hours >> [music] >> is the sampling rate. When a researcher","speaker":null,"is_sponsor":0},{"start_s":236.88,"end_s":244.32,"text":"says continuous, they usually mean high-frequency sampling. When a consumer","speaker":null,"is_sponsor":0},{"start_s":241.8,"end_s":248.64,"text":"wearable says continuous, they often mean, \"Ah, we check in every now and","speaker":null,"is_sponsor":0},{"start_s":246.72,"end_s":253.36,"text":"then, and then we interpolate a bit so the graph looks like a solid line.\" And","speaker":null,"is_sponsor":0},{"start_s":251.2,"end_s":256.56,"text":"if you have a darker skin tone, the LEDs actually have to work harder to get a","speaker":null,"is_sponsor":0},{"start_s":254.84,"end_s":259.32,"text":"readable signal, which can cut that already slim battery life nearly in","speaker":null,"is_sponsor":0},{"start_s":258.72,"end_s":265.24,"text":"half. [music] Now, that isn't to say that the form factor has no benefits. There is a","speaker":null,"is_sponsor":0},{"start_s":263.0,"end_s":268.68,"text":"reason that hospitals clip sensors onto your fingers. They are densely packed","speaker":null,"is_sponsor":0},{"start_s":267.16,"end_s":272.24,"text":"with arteries that are right close to the surface of the skin. But for smart","speaker":null,"is_sponsor":0},{"start_s":270.52,"end_s":276.52,"text":"rings, that's kind of a double-edged sword. Besides being so darn cute and,","speaker":null,"is_sponsor":0},{"start_s":274.448,"end_s":280.4,"text":"[music] you know, fingery, fingers are your body's temperature control meat","speaker":null,"is_sponsor":0},{"start_s":278.2,"end_s":284.68,"text":"sticks. When you have vasoconstriction or dilation","speaker":null,"is_sponsor":0},{"start_s":282.52,"end_s":288.8,"text":"uh due to being cold or due to, say, being in a sauna, that will, again,","speaker":null,"is_sponsor":0},{"start_s":287.04,"end_s":292.4,"text":"change the distribution of blood within the skin and impact your","speaker":null,"is_sponsor":0},{"start_s":290.2,"end_s":296.2,"text":"photoplethysmography signal. Typically, vasoconstriction","speaker":null,"is_sponsor":0},{"start_s":294.04,"end_s":299.28,"text":"or having that blood redistributed away from the surface of","speaker":null,"is_sponsor":0},{"start_s":297.76,"end_s":303.36,"text":"the skin can have a detrimental effect on the PPG. So, it'll decrease your","speaker":null,"is_sponsor":0},{"start_s":301.56,"end_s":306.68,"text":"pulses, it will decrease your signal-to-noise ratio, and then the","speaker":null,"is_sponsor":0},{"start_s":305.12,"end_s":311.48,"text":"opposite is true when you have perfusion. Cold hands equals a weaker","speaker":null,"is_sponsor":0},{"start_s":309.48,"end_s":315.44,"text":"signal, which equals your ring struggling to find your pulse. Lock","speaker":null,"is_sponsor":0},{"start_s":313.28,"end_s":319.84,"text":"outside in the winter or sit next to an aggressive air conditioner, and your","speaker":null,"is_sponsor":0},{"start_s":316.96,"end_s":325.4,"text":"ring huh might think you're a spooky vampire with no pulse. Or Sam Altman.","speaker":null,"is_sponsor":0},{"start_s":322.6,"end_s":328.36,"text":"Unlike the finger, the wrist sits closer to the body's core, [music] staying","speaker":null,"is_sponsor":0},{"start_s":326.56,"end_s":332.4,"text":"warmer and maintaining more consistent blood flow, giving the watch a natural","speaker":null,"is_sponsor":0},{"start_s":330.32,"end_s":335.32,"text":"edge in colder environments. But hey, I mean, if sitting still in a freezing","speaker":null,"is_sponsor":0},{"start_s":333.6,"end_s":339.88,"text":"room isn't your only hobby, what about if you actually exercise?","speaker":null,"is_sponsor":0},{"start_s":337.76,"end_s":343.76,"text":"Even a simple jog is going to slosh your blood around enough to give the sensors","speaker":null,"is_sponsor":0},{"start_s":341.48,"end_s":348.04,"text":"a headache. But for hand heavy lifting, the ring becomes basically decorative.","speaker":null,"is_sponsor":0},{"start_s":346.28,"end_s":353.44,"text":"See, the problem isn't just motion, it's grip. Odoo, your business doesn't need","speaker":null,"is_sponsor":0},{"start_s":351.24,"end_s":357.72,"text":"different apps for signing agreements, running a POS, doing inventory","speaker":null,"is_sponsor":1},{"start_s":355.44,"end_s":361.72,"text":"management, or running email marketing. All you need is Odoo. It's a business","speaker":null,"is_sponsor":1},{"start_s":360.04,"end_s":365.72,"text":"management software with just about anything you could imagine needing","speaker":null,"is_sponsor":1},{"start_s":363.16,"end_s":370.16,"text":"integrated into a single platform. It's customizable and built to be easy to","speaker":null,"is_sponsor":1},{"start_s":367.88,"end_s":375.92,"text":"navigate since you pick and choose only what you need, no extra fluff. And if","speaker":null,"is_sponsor":1},{"start_s":373.32,"end_s":380.6,"text":"you only need one app, it's free. Use our link for a free 15-day trial with no","speaker":null,"is_sponsor":1},{"start_s":378.8,"end_s":384.32,"text":"credit card required. When someone tightly grips a steering","speaker":null,"is_sponsor":1},{"start_s":382.44,"end_s":387.8,"text":"wheel or a barbell, we typically call this motion artifacts. At the uppermost","speaker":null,"is_sponsor":0},{"start_s":386.28,"end_s":392.0,"text":"level of your skin, you have a capillary bed, and when you apply pressure to this, that's the first layer that","speaker":null,"is_sponsor":0},{"start_s":390.52,"end_s":396.68,"text":"actually gets compressed. And so you end up with a a large spike in your photoplethysmography signal. That's not","speaker":null,"is_sponsor":0},{"start_s":395.12,"end_s":401.68,"text":"attributed to your pulsations or your heart rate, which is the thing we want to measure. These motion artifacts and","speaker":null,"is_sponsor":0},{"start_s":400.0,"end_s":405.96,"text":"pressure-induced [music] signal loss hit simultaneously, and they compound fast.","speaker":null,"is_sponsor":0},{"start_s":403.84,"end_s":408.92,"text":"White-knuckling a barbell squeezes blood out of the very capillaries the ring is","speaker":null,"is_sponsor":0},{"start_s":407.32,"end_s":412.68,"text":"trying to read. So, by the time your heart rate has climbed to 160 beats per","speaker":null,"is_sponsor":0},{"start_s":411.28,"end_s":416.08,"text":"minute mid-set, the ring might be reporting a breezy 80. A quick","speaker":null,"is_sponsor":0},{"start_s":414.44,"end_s":420.24,"text":"TechQuickie safety tip, by the way, wearing a metal ring during heavy lifts","speaker":null,"is_sponsor":0},{"start_s":417.88,"end_s":423.76,"text":"is not a good idea. Beyond scratching the finish of your ring, you're actually","speaker":null,"is_sponsor":0},{"start_s":421.76,"end_s":427.16,"text":"risking a degloving accident. Seriously though, do not Google that. The standard","speaker":null,"is_sponsor":0},{"start_s":425.36,"end_s":431.72,"text":"way to deal with motion artifacts is to cross-reference the accelerometer data.","speaker":null,"is_sponsor":0},{"start_s":429.56,"end_s":436.6,"text":"If motion exceeds a specific threshold, then the PPG data just gets discarded","speaker":null,"is_sponsor":0},{"start_s":433.64,"end_s":442.0,"text":"entirely because a gap is better than a wrong number. A 2024 study even found","speaker":null,"is_sponsor":0},{"start_s":439.0,"end_s":443.92,"text":"that you might need to discard up to 70%","speaker":null,"is_sponsor":0},{"start_s":442.0,"end_s":448.16,"text":"of heart rate variability readings due to poor signal quality. To combat this","speaker":null,"is_sponsor":0},{"start_s":446.16,"end_s":453.32,"text":"data trashing, researchers are working on transformer-based AI models to","speaker":null,"is_sponsor":0},{"start_s":450.48,"end_s":457.36,"text":"reconstruct corrupted PPG signals. So, the sensor's tiny, the battery prevents","speaker":null,"is_sponsor":0},{"start_s":455.44,"end_s":461.12,"text":"continuous tracking, cold hands kill the signal, gripping blinds it, and most of","speaker":null,"is_sponsor":0},{"start_s":459.52,"end_s":466.04,"text":"these rings aren't even FDA-regulated medical devices, making them pretty much","speaker":null,"is_sponsor":0},{"start_s":463.12,"end_s":469.32,"text":"high-end accessories with an asterisk. So, are they an overpriced piece of","speaker":null,"is_sponsor":0},{"start_s":468.04,"end_s":473.16,"text":"e-waste? Actually, no. There is one time of day","speaker":null,"is_sponsor":0},{"start_s":471.68,"end_s":477.8,"text":"where almost all of these problems disappear, >> [music] >> and that's during sleep. Unless you're","speaker":null,"is_sponsor":0},{"start_s":476.08,"end_s":481.24,"text":"David Goggins, you're probably aren't gripping a barbell in your sleep, so","speaker":null,"is_sponsor":0},{"start_s":479.4,"end_s":486.44,"text":"your hands are relaxed and your arteries are right at the surface. Smart rings","speaker":null,"is_sponsor":0},{"start_s":483.4,"end_s":487.88,"text":"can get incredibly accurate resting data","speaker":null,"is_sponsor":0},{"start_s":486.44,"end_s":493.8,"text":"while being far more comfortable to sleep in than this darn thing. Aura even","speaker":null,"is_sponsor":0},{"start_s":491.12,"end_s":497.96,"text":"boasts about their .999 correlation with medical-grade ECGs for","speaker":null,"is_sponsor":0},{"start_s":496.0,"end_s":502.56,"text":"resting heart rate, which checks out. Even with a few misbeats, basic average","speaker":null,"is_sponsor":0},{"start_s":500.08,"end_s":505.76,"text":"is easy. Their .984 HRV correlation claim, however, has a massive catch.","speaker":null,"is_sponsor":0},{"start_s":504.4,"end_s":511.52,"text":"Heart rate variability measures millisecond differences between individual beats, and it needs [music]","speaker":null,"is_sponsor":0},{"start_s":509.36,"end_s":515.0,"text":"beat-to-beat continuity. So, a gap in the data doesn't just reduce accuracy,","speaker":null,"is_sponsor":0},{"start_s":513.44,"end_s":518.719,"text":"it invalidates the entire measurement window, which is why smart rings filter","speaker":null,"is_sponsor":0},{"start_s":517.0,"end_s":523.32,"text":"out low-confidence data before reporting. To legally be able to claim","speaker":null,"is_sponsor":0},{"start_s":520.919,"end_s":528.4,"text":"this HRV accuracy, many validation studies use sedentary participants. In","speaker":null,"is_sponsor":0},{"start_s":525.96,"end_s":531.2,"text":"one, no subject's heart rate broke 90 beats [music] per minute, so it's kind","speaker":null,"is_sponsor":0},{"start_s":529.64,"end_s":535.72,"text":"of easy to be accurate when your user's just vibing on the couch. As for the","speaker":null,"is_sponsor":0},{"start_s":533.76,"end_s":540.0,"text":"high-level scores, like sleep score, readiness, and stress, those are","speaker":null,"is_sponsor":0},{"start_s":537.68,"end_s":544.4,"text":"proprietary algorithms that arguably don't mean much. It's kind of a way of","speaker":null,"is_sponsor":0},{"start_s":542.28,"end_s":548.84,"text":"gamifying your sleep to see who [music] can have the most readiness, I suppose,","speaker":null,"is_sponsor":0},{"start_s":547.2,"end_s":553.0,"text":"and to help you justify your $5.99 monthly subscription for the rest of your life. If you want to see the","speaker":null,"is_sponsor":0},{"start_s":551.24,"end_s":556.4,"text":"testing facilities that smart wearables, like rings, are designed in, check out","speaker":null,"is_sponsor":0},{"start_s":554.72,"end_s":561.4,"text":"this video where I visited one in China. It's actually, for all of the dunking on these devices","speaker":null,"is_sponsor":0},{"start_s":559.48,"end_s":564.84,"text":"that we just did, a lot more elaborate and way cooler than you might think.","speaker":null,"is_sponsor":0}],"full_text":"Like the thirsty cast members of The Bachelorette, Samsung Aura and, if rumors are correct, [music] Apple all want to put a ring on it. And why not? The promise of a smart ring is undeniably sexy. A screen-free titanium hoop that tracks your vitals 24/7. Who wouldn't want it? But, like a reality TV marriage, buying a smart ring is sometimes followed by regret. If you've ever wondered why your smart ring thinks you were napping while you were working and yet misses your PR at the gym, that's because, turns out, shrinking an entire lab's worth of equipment down to the size of a piece of jewelry requires some serious engineering compromises. Compromises that could be fat-fingering your biometric data. Let's break these devices down, starting with the main sensor. [music] PPG, or photoplethysmography, is a fancy name for shining light into your skin and measuring how much bounces back. In a hospital, they'll clip a sensor onto your fingertip, yield transmissive PPG. It's incredibly accurate because the signal is unobstructed. Smartwatches, on the other hand, use reflective PPG, where the sensor and the photodiode are on the same side. Fun fact, by the way, they use green light because your blood absorbs it like a sponge, providing a high-contrast signal. Depending on, you know, how far apart your photodiode is, if it's, say, on the curvature of a ring, you may actually kind of be between these modalities, where you're somewhat like in a transflective approach. You may see behavior of both like a reflective and a transmissive PPG. Smart rings can occupy a weird middle ground. Because the sensors wrap around your finger, light travels further through your skin than it would from a smart watch. This gives the ring a slight signal advantage, but it's one that unfortunately gets dragged down by the constraints that arise from its size >> [music] >> and from its battery. >> The amount of light you need in order to measure an appreciable pulse is proportional also to the active area of the photodiode that you're using to sense it with. So, a bigger photodiode, a bigger sensor, means you can use less light, less current, in order to perform the same relative measurement. If you only just shrink the photodiode itself, you're going to be decreasing your your signal-to-noise ratio and have to, you know, boost your LED light in order to accommodate for that. You can think of it kind of like listening to a conversation in a crowded bar. A smartwatch stands next to a person with a large, directional microphone. A smart ring, on the other hand, is trying to hear them from across the room using a tiny little spy mic taped to their collar, which brings us to the battery. The Samsung Galaxy Watch Ultra packs 590 mA hours. >> [music] >> The Galaxy Ring, 17 to 22 and 1/2. And yet, the ring claims it lasts for up to 7 days. How? Well, because it doesn't. Both devices use duty cycling to extend their usable charge time, but because the watch has a larger battery, one intense session isn't going to drain it. The ring, on the other hand, has about the battery of a Cheerio. [music] They have also large dormant periods, where the ring simply is not measuring at all. And and so you can kind of think of it as like interlacing on top of interlacing, you know, in order to [music] make it so maybe you only measure the pulsations, measure the heart rate, pulse ox, you know, for a minute, you know, every 10, 15, 20 minutes, for example, in order to to keep conserving uh power. [music] To put this in perspective, when the Franklin Research Lab built their own DIY smart ring, the battery gave out after about 4 to 6 hours of continuous use. So, if we take that as a baseline for true continuous tracking, to survive a full 168-hour week of nonstop data collection, you'd need to wear 34 rings and swap them out like ammunition magazines. By Wednesday, you'd look more like the Divination instructor at Hogwarts than like a fitness enthusiast. >> [music] >> The reason that smart ring bands can claim a week while Dr. Franklin gets only 5 hours >> [music] >> is the sampling rate. When a researcher says continuous, they usually mean high-frequency sampling. When a consumer wearable says continuous, they often mean, \"Ah, we check in every now and then, and then we interpolate a bit so the graph looks like a solid line.\" And if you have a darker skin tone, the LEDs actually have to work harder to get a readable signal, which can cut that already slim battery life nearly in half. [music] Now, that isn't to say that the form factor has no benefits. There is a reason that hospitals clip sensors onto your fingers. They are densely packed with arteries that are right close to the surface of the skin. But for smart rings, that's kind of a double-edged sword. Besides being so darn cute and, [music] you know, fingery, fingers are your body's temperature control meat sticks. When you have vasoconstriction or dilation uh due to being cold or due to, say, being in a sauna, that will, again, change the distribution of blood within the skin and impact your photoplethysmography signal. Typically, vasoconstriction or having that blood redistributed away from the surface of the skin can have a detrimental effect on the PPG. So, it'll decrease your pulses, it will decrease your signal-to-noise ratio, and then the opposite is true when you have perfusion. Cold hands equals a weaker signal, which equals your ring struggling to find your pulse. Lock outside in the winter or sit next to an aggressive air conditioner, and your ring huh might think you're a spooky vampire with no pulse. Or Sam Altman. Unlike the finger, the wrist sits closer to the body's core, [music] staying warmer and maintaining more consistent blood flow, giving the watch a natural edge in colder environments. But hey, I mean, if sitting still in a freezing room isn't your only hobby, what about if you actually exercise? Even a simple jog is going to slosh your blood around enough to give the sensors a headache. But for hand heavy lifting, the ring becomes basically decorative. See, the problem isn't just motion, it's grip. Odoo, your business doesn't need different apps for signing agreements, running a POS, doing inventory management, or running email marketing. All you need is Odoo. It's a business management software with just about anything you could imagine needing integrated into a single platform. It's customizable and built to be easy to navigate since you pick and choose only what you need, no extra fluff. And if you only need one app, it's free. Use our link for a free 15-day trial with no credit card required. When someone tightly grips a steering wheel or a barbell, we typically call this motion artifacts. At the uppermost level of your skin, you have a capillary bed, and when you apply pressure to this, that's the first layer that actually gets compressed. And so you end up with a a large spike in your photoplethysmography signal. That's not attributed to your pulsations or your heart rate, which is the thing we want to measure. These motion artifacts and pressure-induced [music] signal loss hit simultaneously, and they compound fast. White-knuckling a barbell squeezes blood out of the very capillaries the ring is trying to read. So, by the time your heart rate has climbed to 160 beats per minute mid-set, the ring might be reporting a breezy 80. A quick TechQuickie safety tip, by the way, wearing a metal ring during heavy lifts is not a good idea. Beyond scratching the finish of your ring, you're actually risking a degloving accident. Seriously though, do not Google that. The standard way to deal with motion artifacts is to cross-reference the accelerometer data. If motion exceeds a specific threshold, then the PPG data just gets discarded entirely because a gap is better than a wrong number. A 2024 study even found that you might need to discard up to 70% of heart rate variability readings due to poor signal quality. To combat this data trashing, researchers are working on transformer-based AI models to reconstruct corrupted PPG signals. So, the sensor's tiny, the battery prevents continuous tracking, cold hands kill the signal, gripping blinds it, and most of these rings aren't even FDA-regulated medical devices, making them pretty much high-end accessories with an asterisk. So, are they an overpriced piece of e-waste? Actually, no. There is one time of day where almost all of these problems disappear, >> [music] >> and that's during sleep. Unless you're David Goggins, you're probably aren't gripping a barbell in your sleep, so your hands are relaxed and your arteries are right at the surface. Smart rings can get incredibly accurate resting data while being far more comfortable to sleep in than this darn thing. Aura even boasts about their .999 correlation with medical-grade ECGs for resting heart rate, which checks out. Even with a few misbeats, basic average is easy. Their .984 HRV correlation claim, however, has a massive catch. Heart rate variability measures millisecond differences between individual beats, and it needs [music] beat-to-beat continuity. So, a gap in the data doesn't just reduce accuracy, it invalidates the entire measurement window, which is why smart rings filter out low-confidence data before reporting. To legally be able to claim this HRV accuracy, many validation studies use sedentary participants. In one, no subject's heart rate broke 90 beats [music] per minute, so it's kind of easy to be accurate when your user's just vibing on the couch. As for the high-level scores, like sleep score, readiness, and stress, those are proprietary algorithms that arguably don't mean much. It's kind of a way of gamifying your sleep to see who [music] can have the most readiness, I suppose, and to help you justify your $5.99 monthly subscription for the rest of your life. If you want to see the testing facilities that smart wearables, like rings, are designed in, check out this video where I visited one in China. It's actually, for all of the dunking on these devices that we just did, a lot more elaborate and way cooler than you might think."}