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S+ by ResMed review: A wireless tracker with the goal of improving your sleep

No strap or mattress pad needed. The S+ can wirelessly monitor your heart rate, breathing and movement to track the quality and length of your sleep.

Dan Graziano Associate Editor / How To
Dan Graziano is an associate editor for CNET. His work has appeared on BGR, Fox News, Fox Business, and Yahoo News, among other publications. When he isn't tinkering with the latest gadgets and gizmos, he can be found enjoying the sights and sounds of New York City.
Dan Graziano
5 min read

I'm a terrible sleeper. I know this because almost all of the activity trackers I have tested over the past few months include some form of sleep tracking and they have told me that I am a terrible sleeper. I toss and turn throughout the night and wake up frequently. This isn't news to me. I've had trouble sleeping since I was a child.


S+ by ResMed

The Good

The S+ by ResMed can accurately track your sleep without a wristband or a mattress pad. The app (Android and iOS) offers detailed information each day on your sleep habits and provides feedback to help improve your sleep.

The Bad

Sleep tracking isn't automatic and the device is expensive for something that only tracks your nighttime activities. The tracker can also be confused by someone else sharing the bed or if you move out of range of the sensor.

The Bottom Line

The S+ offers accurate tracking and insightful sleep data that any insomniac will appreciate.

All of these trackers could tell me different metrics about my sleep, but none of them offered feedback on how to improve my sleep. That's where the S+ from ResMed comes into play. In addition to tracking your sleep each night, this wireless bedside tracker provides daily tips and insight to help improve your sleep habits.

The S+ is available for $150 in the US. It's pricey considering it only tracks sleep, especially since you can buy a Fitbit Charge or Jawbone Up24 for both activity and sleep tracking, for cheaper.

S+ by ResMed: Wireless sleep tracking and daily feedback

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What is it?

Almost every sleep tracker on the market requires some sort of wristband or mattress pad. The S+ is different. It sits next to your bed and can wirelessly track your sleeping habits. The sensor is quite small, but it is placed inside of a stand to ensure that it can properly record your breathing and heart rate. Altogether, it's about the size of a milk carton. The minimalist design helped it blend well with my furniture, although in some bedrooms it may stand out. There is no battery on the S+ and it must be plugged in at all times to function. It connects using a normal Micro-USB port and adapter, however the adapter also has a second port for charging your smartphone.

Sarah Tew/CNET

What does it do?

As you are about to go to sleep each night you must enable sleep mode on the sensor. You would think that the S+ could automatically enter sleep mode, especially given how smart it is, but this is not the case. Early on I went a few nights without sleep tracking because I would forget to enable the S+.

Enabling sleep mode must be done from your Android or iOS device using the company's mobile app. You will then be asked about your stress levels throughout the day, how many alcoholic drinks you consumed, how many caffeinated drinks you had and how long you exercised for.

A so-called "Smart Alarm" feature can be set to wake you up at the optimal time within a time frame you indicate each morning. The alarm didn't feel all that smart to be honest and I'm not exactly sure how it determined the "optimal" wake-up time, but nevertheless it got the job done and woke me up around the time I requested.

Sarah Tew/CNET

As I lie in bed each night, I toss and turn and my mind wanders. I think about unfinished tasks, emails I need to respond to and friends I haven't seen in a while. Sometimes I'm even left thinking about odd concepts for movies or books I will surely never write. To solve this problem, the S+ includes a "Mind Clear" feature. The idea is for you to write or speak memos to get them off your mind. Your memos will then be waiting for you when you wake up the following morning.

There is also a "Relax to Sleep" mode that will synchronize relaxing sounds like the ocean or the forest to your breathing. The sounds start out loud and as you drift off the they get quieter until they ultimately turn off. I like this feature in concept, but I found it distracting when I actually used it. I would focus too much on the sounds and it would make my insomnia even worse. After using it for a few nights, I decided the feature wasn't for me.

The nighttime process should only take a few minutes to complete. Once everything has been set, it's time to get some rest. The S+ will wirelessly monitor your breathing, heart rate and movement to track your sleep.

Sarah Tew/CNET

In the morning, you will be greeted with a number from 1 to 100 in the mobile app. This is your sleep score and it's calculated based on the quality and length of your sleep. You will also see detailed information about the amount of time you were awake, the amount of REM, deep and light sleep you achieved, and the number of disruptions you had in the middle of the night. There are two battery icons with percentages next to them. One shows how recharged your mind is based on the amount of REM sleep you got, while the other shows how rested your body is based on your deep sleep.

Sarah Tew/CNET

The mobile app allows you to view your sleep history from the past day, week, month and year. The interface is colorful, clean and easy to navigate. Perhaps the most important feature in the app is S+ Mentor. This is where you will find sleeping facts and tips on how to improve your sleep. For example, after clocking me as taking 35 minutes to fall asleep one night, the S+ recommended that I take a hot shower or bath an hour and a half before bed. The app also sent me a reminder as I got closer to my bed time.

Sarah Tew/CNET

These tips were mostly helpful, although sometimes it seems like they ran out of feedback to give. One morning I was greeted with a "sleep fact" that explained why gunk builds up in the corner of our eyes. No thank you.

Does it work?

Now the question everyone is going to ask: does the S+ actually work? Yes and no. While I saw no immediate improvements in my sleep, I have learned more about my sleeping habits and how I can improve them. The information you receive from the S+ each morning is better than what you get from most of the activity trackers out there, and it's one of the few that attempts to improve your sleep, not just track it. It isn't without its faults, though.

Sarah Tew/CNET

The S+ can only capture information for one person at a time. I did notice that it would continue to record my girlfriend (presumably thinking it was me) if I left the bed in the middle of the night. There were also times when I would get out of range of the sensor simply by rolling to the opposite side of my queen bed, which would cause inaccurate results the following morning. You would think owning a second sensor would solve both of these problems; however, two sensors cannot function properly in the same room.

The S+ doesn't track your sleep automatically and it's a bit pricey, but when it's all said and done, I enjoyed my time with the device. The data and feedback you receive each morning are adequately helpful and the sleep tracking appeared to be quite accurate. I recommend checking out the S+ if you want to know more about your sleep habits. It's easy to use and better than having to wear a wristband or place a pad under your mattress. ResMed also offers a 30-day money back guarantee if you aren't satisfied, which makes that price tag easier to swallow.


S+ by ResMed

Score Breakdown

Style 7Features 8Ease of use 7