Resmed S+ Review

[amazon box=”B00NP52QE0″]


A good value, sophisticated sleep tracker with great software and a unique wireless bio-sensor that monitors your movement and breathing. If you don’t need 3rd party data sharing or automatic sleep detection the S+ is a solid performer.

The good:
  • Unique, wireless, non-contact technology
  • Solid, well engineered product
  • Detailed, personalised sleep coaching
  • Bedroom environmental sensors
  • Great app
Not so good:
  • No automatic sleep detection
  • No data export or 3rd party data sharing


[toc] Founded in 1989, Resmed made its name in manufacturing equipment to treat and manage sleep apnea, chronic obstructive pulmonary disease (COPD) and other chronic diseases.

Operating in over 100 countries and with over 5000 staff, Resmed know a thing or two about manufacturing sleep products. Normally specialising in CPAP (continuous positive airway pressure) machines and breathing masks, The S+ is Resmed’s first (and only, so far) foray into the world of sleep tracking.

Interestingly, Resmed have chosen not to emulate the competition; but instead they’ve based the S+ on a unique, new type of wireless, non-contact technology. In doing so, they stand out from the crowd in being the only sleep tracking device that works without having to physically touch your body or sleeping surface.

Contactless sleep monitoring

The S+ works by sending out ultra-low power radio waves in the 10.5Ghz spectrum. There’s no need to worry about any harmful radiation effects as the signals are less than a tenth of the power of Bluetooth. Similar to a bat’s echo location abilities, the S+ sends out pulses of radio waves and then listens for the signal’s ‘echo’.

When your body moves, the S+ detects this as a phase difference in the echo’ed signal and using proprietary algorithms, calculates your breathing rate and sleep metrics. The high frequency of the radio signal means that clothing and blankets are rendered ‘invisible’ to the S+.

Other features

The S+ also sports environmental sensors that monitor your bedroom conditions too,, measuring light levels, ambient temperature and noise. And as well as being innovative in the hardware stakes, the S+ also features a suite of novel app features and personalized feedback on your sleep data not seen on any other sleep tracker.

So, enough of the introduction, how did the S+ fare in our user review?

First Impressions

As veterans of the sleep technology market, Resmed have unsurprisingly put a lot of thought into the packaging and design of the S+. It’s fair to say that out of the box, the device is quite unassuming and most people would be hard-pressed to guess what it actually is.

The product is physically made up of two parts; a rectangular, brushed metal frame and a more cubic, white plastic ‘pod’ which contains all of the electronics and sensors. The frame essentially serves only one purpose – to raise the unit up high enough so that the S+ has enough clearance from the surface of your bedside table. Placing the pod directly on a tabletop or flat surface would diminish the performance of the radio wave technology that S+ relies on.

That said, the frame uses a simple magnetic clip to attach to the housing, so there’s nothing stopping you from getting rid of the frame and experiment with other ways to position the S+. In addition, the white housing can pivot in the frame so you can angle the positioning just right.


Aesthetically, the device is, let’s say, a little middle of the road. It doesn’t have the design eccentricity of the Withings Aura, but it’s not particularly ugly either. Resmed have designed the S+ with a neutral-industrial chic and it’s safe to say that its grey and white lines wouldn’t look out of place in the majority of bedrooms.

In terms of build quality, as you would expect from a company that has been manufacturing medical equipment for over 25 years, the S+ is solidly constructed and feels like a premium product. The whole thing is also surprisingly lightweight for its size, weighing just a little over 2 pounds.

As for wires and connectivity, there’s just a single micro-USB socket on the rear of the pod, however, helpfully the power supply has a dual USB socket letting you charge your phone as well.


Installing the app

To get started with the S+ you first have to setup an account with Resmed at Once you’ve completed this you’re ready to download the Resmed app which is available for iOs and Android devices.

When you first login you’ll be prompted to fill out a quite lengthy questionnaire concerning your profile settings. These include things such as your weight, height, age, gender but also some quite personal details regarding your sleep habits such as whether you take prescription drugs

These questions are so that Resmed can better tailor the personalised feedback it sends each night but fortunately, none of these details are mandatory, so I just filled in the basic height and weight parameters and didn’t bother to complete the rest.

Setting up the S+

Once you’ve completed paired your phone via Bluetooth with the S+ the setup is pretty much a case of optimizing the positioning of the device so that it picks up your breathing, heart rate and movement patterns most efficiently.

The pod needs to be at least 1 metre, or an arm’s length away from your body, and be angled down facing your chest. In order for the radio-wave technology to work the bottom of the pod needs to be above the level of your mattress and there should be a clear line of sight, with no obstructions between the the S+ and your body.

Interestingly, Resmed say that the S+ will work regardless of whether you have a bed partner or not, asl long as you get the positioning right. Whilst I didn’t seem to encounter any problems in this respect, personally I find it difficult to imagine how the device could work out which foot/limb/shoulder etc belongs to which bed partner, especially if you are fond of snuggling up real tight at night. I guess we have to take Resmed’s word on this one.

Before you go to sleep, so that you can make sure you’ve got the positioning right, there’s a helpful feature in the app – the Pre-Sleep function, in which you can see the real-time readings from the S+ motion sensor. It’s really quite a cool demonstration of how sensitive the S+ is – see the video I posted below.

In Use

Apart from the non-contact motion sensor, the S+ differentiates itself from the crowd with a extensive selection of pre-sleep app functions that are designed to do two things, 1) gather information about the preceding day so that it can include these factors in your post-sleep analysis, and 2) prepare your body and mind for a relaxing night’s sleep

Going to sleep

When it comes to actually activating the S+ into sleep tracking mode, this is a manual process, there’s no way for the device to automatically sense when you’re in bed and ready to drift off.

Automatic sleep tracking is something that sleep trackers like the Withings Aura and Beddit Smart can do, but with the S+ you have to manually activate the device by pressing the ‘Sleep’ button on the app. You also need to make sure that your phone is plugged in overnight as the S+ is in constant communication with the app. If your phone runs out of battery in the middle of the night, you will lose all of your sleep data.

Waking Up

Like a lot of other devices, the S+ features a ‘Smart Alarm’ function. It’s ‘smart’ because the alarm attempts to prevent sleep inertia – the groggy sensation that occurs when you wake up abruptly, typically when you are in deep sleep.

With the S+, instead of setting a fixed time to wake up, you can set a time window from 15 to 30 minutes, (say 7:30am-8am for example) for when you want your alarm to go off. The device will then attempt to wake you only if it detects that you are in a light sleep phase. If you’re in an unshakeably deep slumber, the alarm will sound at the end of your allotted time window.

When you’re up, you simply press ‘Stop Tracking’ on the app. Unlike some other devices like the Withings Aura and Neuroon, you don’t have to wait for your data to download, sync, or be calculated. Because the app is always running throughout the night,

You get a more or less instant readout of your sleep analytics as soon as you stop tracking.


Resmed have put a great deal of thought and effort into designing the software that accompanies the S+. The app itself, available on both iOS and Android packs loads of functionality, but the designers and developers have managed to make the interface user friendly, uncluttered and visually appealing.

In addition to the phone app, all of your sleep data is mirrored in the web platform at allowing you to scrutinize your data and graphs on a bigger screen in more detail.

Before you sleep

The S+ has three software components that are designed to be used before you actually fall asleep. The first is the Pre-Sleep mode which give you a range of options before you actually start tracking your sleep.

Once you’ve established a Bluetooth connection, the app displays the Breathing Graph where you can get a real-time visual display from the wireless bio-motion sensor in the S+. The breathing graph doesn’t really serve any function either than to check if the S+ is positioned correctly, but it’s a really cool demonstration of how sensitive and accurate the device is in terms of picking up the minutest of body movements.

Once you’re happy with the breathing graph, we have the pre-sleep questionnaire. This is designed to gather information about your day and asks a series of short questions about your alcohol and caffeine intake, plus your stress and activity levels.

The pre-sleep questionnaire is completely optional; if you don’t feel comfortable about entering such personal details you don’t have to. But if you’re prepared to religiously complete the Pre-Sleep questionnaire every night you’ll have access to lots of useful data and graphs – most apparent in the web platform. Whilst I personally didn’t take advantage of this feature, I can see how useful it might be is you’re trying to figure out if coffee, a glass of wine or that late night workout if affecting your sleep in any way.

Relax to Sleep

This is another feature designed to help ease you into slumber. Relax to Sleep plays a soothing audio tone from your phone – there are around 20 to choose from including crashing waves to musical riffs.

You activate this function just before you sleep and the idea is that the sound helps soothe and relax you as you nod off. The clever part is that after two minutes, the S+, when it has detected your breathing rate, will synchronised the audio track to the match the rhythms of your breaths. Then, the soothing sound starts to slow down in tempo, and after a while it automatically switches off.

Mind Clear

The last Pre-Sleep feature is Mind Clear – essentially this is a memo app where your can take notes or record your voice. The idea is that if you have any racing thoughts going through your head before bedtime, you can jot down these thoughts or record a 60 second voice memo so that you can relax and forget about it, knowing that you’ll be able to review your thoughts in the morning.

Sleep Analytics

The most important element of any sleep tracking device is how well it measures and presents your sleep data. As we said before, the S+ software does a great job at presenting your sleep metrics in a clear, easy to access layout.

S+ gives you daily, customized feedback on your sleep, and suggestions on how to improve it. You’ll also have a series of easy-to-use, interactive tools that allow you to work with your own sleep data, and to properly understand the way you sleep. The S+ analytic toolkit helps you understand short-term sleep concerns and longer-term trends, providing you with a range of options to see how your sleep evolves so you can set new, sleep-better goals.

So what does the S+ actually measure?

In terms of sensors, the S+ seems on the surface to lack many of the features found in other advanced sleep trackers. There’s no heart rate monitor or pulse oximeter, no EEG electrodes or body temperature measurements. The only two measurements the S+ records are your body movement and breathing rate.

However, from these two metrics, Resmed have created an algorithm that can detect the following sleep stages:

  • Wakefulness
  • light sleep
  • deep sleep
  • REM.

Sleep Score

The app gives a clear and colourful hypnogram-like display as well as a Sleep Score – a 0-100 scale that combines multiple elements of your sleep metrics against averages for your age and gender.
Resmed S+ app Sleep Score and hypnogram

As with all consumer sleep trackers, the Resmed’s sleep score is a proprietary measurement but the helpfully, along with your overall percentage score, you get a breakdown of your total sleep time, along with the amount of time spent in your various sleep stages.

Sleep Recharge

In addition the S+ gives you a ‘Sleep Recharge’ score. This gives you two further measurements, Mind Recharge, the percentage of time you spent in REM, and Body Recharge, the percentage of time you spent in deep sleep.

Whilst the app layout is very good, you can get even more detailed graphs and reports via the web interface. Here you can download customized sleep reports, view your sleep history, get insights on your different sleep stages and review customized feedback on your sleep performance, including strategies to improve your sleep.

S+ Mentor

S+Mentor gives you personalized suggestions based on your sleep data gathered from the S+. According to, S+ Mentor uses “the very latest in sleep science, including information and insights gained from more than 2 million nights worth of sleep data.

So, not surprisingly, the feedback you get is full of useful tips that are tailored to your own personal sleep habits. S+ Mentor appears via notifications on your phone and also via the web platform and the advice is wide ranging and includes tips and strategies on how to improve your sleep including, Sleep facts, Exercise advice, Sleep duration, advice on sleep stages (REM, deep sleep, light sleep), awakenings and lots more.

The level of detail is quite high in S+ Mentor and it’s one of the best implementations of personalized sleep feedback I’ve seen on any sleep tracker.

Data export, sharing and compatibility

For all the efforts that have been taken in designing a great app for the S+, one area that’s lacking is the ability to share and integrate your sleep data with 3rd party software. Currently there’s no way to export your sleep data outside of the S+ ecosystem.

Unlike many other sleep trackers there’s no way to download your sleep data in CSV format to an Excel spreadsheet, nor are there any integrations with some of the big digital health platforms like Apple Health or Google Fit.

Although data export is promised as a future upgrade, for now at least, you can only view your sleep data within the Resmed software.


The S+ is an attractive and unobtrusive sleep tracking solution with an accurate bio-sensor that uses unique radio wave technology.

Resmed’s long history of manufacturing products for the sleep health market shows in the quality and reliability of the S+. In addition to the good hardware design, Resmed have also built a great companion app that’s feature rich, easy to use gives detailed feedback and suggestions to improve your sleep.
If you can live without automatic sleep detection and don’t need to export your sleep data to a third-party platform, the S+ is a good value, sophisticated sleep tracker that’s easy to use and won’t get in your way.[amazon box=”B00NP52QE0″]

Leave a Comment