Owlet Smart Sock Plus monitors a child's heart rate and oxygen levels while they sleep

If you’ve spent time with young children, you’ll know that looking after one requires a certain amount of trust and a lot of guesswork: they trust that you are doing the right thing, and you do a lot of guessing about what they need.

When we brought our first child home from the hospital, we spent a lot of time making sure that she was still actually breathing, not helped by the tendency babies have to occasionally hold their breath just for a second or too longer than is comfortable.

Video baby monitors have helped with the anxious early months, but they don’t tell the whole story. Which is why there is now a range of baby monitors that will keep an eye on movement and let you know if something out of the ordinary has occurred.

The Owlet Smart Sock Plus is a baby monitor with a difference. It doesn’t use video or audio, although you can add a compatible Owlet camera if you want. Instead it concentrates on two things: heart rate and oxygen levels.

The system has four elements: the Owlet sensor, which is clinically validated and uses pulse oximetry to measure heart rate and oxygen; the fabric sock, which keeps the sensor close to the baby’s skin; the base, which charges the sensor and also delivers alerts and alarms; and the Owlet app, which receives all the data and alerts, and allows you to keep a close watch on your child.

The sock is more of a Velcro wrap, with very clear instructions on where it needs to be positioned. You can choose which foot you’d prefer to have the monitor on, and there are a range of colours and sizes to choose from. The Plus version includes larger socks to make the monitor work for a child up to five years of age, or 25kg.

It was a bit fiddly at first, but if you are using this system from birth, you will have the knack of getting the sock fitted correctly long before they turn into a wriggly one year old and beyond.

Before you fit the monitor though, you have to charge the sensor. That is a relatively simple procedure, with the base for the monitor also acting as the charger. Pop it on for up to 90 minutes and you will get a full night of monitoring out of the device.

Once you have that done, you can connect the sensor to your app, set up your child profile and start monitoring. Once the sock is on, you’ll be able to see your child’s vitals, and if they go outside certain presets, you will be alerted immediately.

The base also emits an alarm when the sock loses track of your child’s vitals. That happened twice in the middle of the night: once when the battery in the sensor died overnight; and once when my child decided the middle of the night was the best time to remove his socks, and the smart sock.

It’s not a rude awakening, but it was a little creepy to wake up to a lullaby tinkling from the corner. The base light also changes colour to notify you when there is an alert you need to check out.

One thing to note: this monitor is clinically validated, but it is not a medical device. So while it will monitor your child’s vital statistics, it is not a substitute for medical care when it is necessary.

But it does help bring peace of mind, and a lot of data. You can view sleep trends and health data night by night, so any changes will be recorded over time. Total hours slept, number of waking hours and overall sleep quality will all be recorded, which is particularly handy if you have a poor sleeper, and can’t keep track of it all.

The good: The device is easy to work, with clear instructions in the app as you go. It won’t require a degree in IT to get it connected to your phone, and once you are connected, there is no real maintenance required.

The battery charges quickly too, so you’ll get eight hours of use in less than an hour. The best thing to do is keep the dock at your bedside so you can pop the sensor on as it is removed each morning from your child’s foot.

There are no alarms that blare if something happens in the middle of the night either. If your child removes the sock, for example, you’ll be woken by a gentle — but effective — lullaby alarm.

The not so good: The device needs a smartphone to work, so if someone else is looking after your child overnight, you will need to set up their phone for access, or have a second device to hand over. Then there is the wifi situation to negotiate — fine if the child is staying in your home, but if you need to take it elsewhere, there’s a bit of settings changes required.

It’s also more expensive than the standard audio or video monitor although it does monitor different things.

The rest: The device will work with socks or pyjamas with feet over the smart sock; just make sure the sensor has full contact with the child’s skin. That’s also handy if you have a child prone to removing the smart sock in the night. You can also get different colours and sizes, so the Owlet will work with kids up to five years of age, depending on their size, of course.

The verdict: Expensive, but may well bring you peace of mind.