Under Mattress Sleep Tracker with HRV

I purchased the Emfit QS in January 2018 and have spent the last year sleeping with it. First, it is non-evasive. You don't have to put anything on your body, turn anything on or start/stop anything before and after sleeping. You simply lay in bed, it senses your presence, begins recording and uploads your data during the night to the Emfit servers. When you exit bed in the morning it recognizes it and begins to put together a picture of your night of sleep. By the time I have my coffee made, I can jump on my phone or look at my computer and get all the data. And there is a ton of data it provides: sleep time/score, breakdown of light/deep/REM cycles, HRV w/ nervous system balance, avg and resting heart rate, respiratory rate, movement/restlessness and finally a proprietary recovery score (that probably still needs some work).The next question people ask is: are the metrics accurate? I also wear an Oura Ring 24/7. It, like the Emfit QS, tracks all the metrics mentioned above. When comparing the results of the two devices, while not matching exactly, show a very clear correlation. They are identical in the sense that when one shows a lower HRV or high HR, the other device has recorded the same trend. Then you have to look at the results provided by the QS and compare it to what you think should be happening, I've found they gel. For example, I was in a bad bike vs car accident in April 2018 that knocked me out of triathlon training for about 5 months while I recovered. During that period the Emfit recorded much high HRV values while recording high resting heart rate values as I lost fitness and aerobic conditioning. Weeks after returning to training, HRV numbers began to drop while my resting HR lowered as well.I have tried several different sleep trackers and HRV/HR measuring tools. This and my Oura Ring are 1 and 1a on the list of effective devices. If you are looking for a hands-off biohacking/recovery measuring/sleep tracking tool I would highly recommend this.Let me cover some of the negatives. I had, and others have reported, some connection issues with their home WiFi. I did find it quirky when I first set it up and had difficulty getting it to connect. Once connected though, I have had no drops and there has not been a single night that data was not recorded. Next, there is no option to place it in airplane mode. There is no internal memory to record during the night and then upload the data later. The device it constantly reaching out to your WiFi every six seconds and uploading data while you sleep. For some concerned about having a WiFi signal that close to you every night, this may not be the device for you. Having said that, the Emfit QS does come with a long power cord and a transmitting device that you can place up to six feet from your bed. Nevertheless, a semi-easy update to this device would be a 2.0 model with internal memory that can turns itself off, record your data all night and then turn on and upload the recorded data once you out of bed. Lastly, if you spend a lot of time in your bed, say watching TV or reading before you sleep, the device night confuse it with you attempting to fall asleep unsuccessfully. I read for at least 30 minutes before I turn the lights off. I found that if I just get out of bed to check if the doors are locked after reading, the device recognizes my sleep patterns enough that it does not record the extra time.A couple of other side notes. I have a Tuff N Needle memory foam mattress. It provides no difficulty in getting any bio-metric signals through it. It also does not pick up my wife's signals when she sleeps, even if we are up against each other.Overall it has proved to be a solid device that provides good, valid sleep and recovery data.

I would recommend, with caution. I bought this after reading a lot of reviews and determining this was the most accurate sleep monitor. My thinking was, If you can't trust the accuracy of a monitor, the data is going to be useless to you. I bought it for my sleep problems. I am not an athlete so I didn't use the heart rate variability data etc.Setup was super simple. I was able to connect it to WiFi simply by pressing the button on my router, then using a paper clip on the Emfit QS. My sleep info gets sent to the internet automatically and reliably and it is always there in my browser when I wake up. The only problem I had with setup was I have a very thick mattress with no box so I basically had to slice my mattress open and put the sensor in under the mattress pad.It gives you a lot of information, from which you can piece together how you're sleeping. However, as I found, you cannot rely 100% on the total sleep and sleep stage classification. The accuracy of these numbers is questionable. For instance, my child was lying in my bed reading for 2 hours and apparently not only did he get 1.5 hours sleep, but he got 1/2 hour of REM sleep! Pretty good for being awake!Having said that, I have reason to believe the toss & turn data is accurate since the sensor for this is pretty basic so you can use this data to clearly figure out when no sleep is happening and do the math to figure out your total sleep. So in order to keep track of my sleep I need to analyze the data, add up the numbers, and keep a separate spreadsheet. Not everybody's willing to do this, but it works for me (so far).I am planning to buy a Fitbit Alta HR so I can compare results.

The Emfit QS is amazing in two ways. One is the amount of data it provides. The other is how it works -- that it can pick up your heart's movement through even a thick mattress! Sure, it's not as accurate as connecting probes to your body, but it seems to as accurate as or better than the less convenient optical arm bands or ring.But it isn't for everyone. Though a sleep "score" is provided, you don't get the full value unless you are willing to invest in interpreting the data.The other issue is that it's become clear that Emfit is a "small" company with a niche (i.e. small) customer base. Very friendly people on the phone, but don't expect a 24x7 team operations team behind the cloud service. I had the misfortune of receiving my unit on a day their servers were down and spent quite a bit of time wondering whether I did something wrong or received a defective unit. Eventually, we concluded that everything is set up correctly and should be working -- but had to wait until morning in Finland for the HQ team to check on the server. Sure enough, things came alive at what looked to be 6'ish AM UTC. So, you need to be willing to deal with a small team of dedicated scientists, etc., instead of a large scale mainstream consumer company.