Circular Ring: Help

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The Circular ring: continuous Heart Rate monitoring

The ring has an optical infrared & red pulse sensor that allows you to record and display in real-time and for later analyses/recommendations on the App. 

How is Heart Rate measured?

Each contraction of the heart results in a blood volume pulse which propagates through the bigger arteries towards the small capillaries. We can all feel this by placing a finger on top of our arteries on our neck or the palmar side of our wrist. The same happens on your finger.

The optical heart rate sensors use a methodology called photoplethysmography (PPG). PPG is a technical term for shining light into the skin and measuring the amount of light that is scattered by blood flow. That is a bit of an oversimplification, but PPG is based on the fact that light entering the body will scatter in a predictable manner as the blood flow dynamics change, such as with changes in blood pulse rates (heart rate) or with changes in blood volume (cardiac output).

In PPG recording, you don’t need electrodes, but just a device that has a proper LED and a photo receiver. That’s why it’s a common method used in wearables, such as in the Circular ring.

Infrared light travels deeper into our tissues and enables more accurate measurements than other wavelengths of light such as green or red light.

A great benefit of having a device like the Circular ring on your finger is that is most likely one of the most optimal places for PPG-based tracking. The reason being that it has the suitable arteries and capillaries for clear blood volume pulse signals, making the optical measurement more reliable and accurate. Besides, there are no moving parts between the joints in fingers, meaning that the ring sits firmly and doesn’t move. 

Live Heart Rate Circular

How can Heart Rate help me?

Heart Rate is the main component alongside to your movements for every Circular sleep, activity and wellness analyses.

Here is a list of the different useful factors that derive from your Heart Rate.

Heart Rate Variability

HRV then leads to sleep analyses, respiration rate, wellness analyses, stress and recovery analyses.

To know more about HRV: Understanding Heart Rate Variability (HRV)

Rested Heart Rate

RHR is an excellent indicator of your overall wellness performance, to be correlated with your HRV.

To know more about RHR: What increase and decrease Rested Heart Rate (RHR)?

Maximum Heart Rate

MHR then leads to heart training zone.

To know more about MHR: Why Max Heart Rate (MHR) is important to know

Activity intensities

Activity intensities describe the types of effort that you produce (which trigger different results) to focus on efforts that match your performance goals.

To know more about Activity intensity: How Circular tracks your Activity intensity

VO2 Max

VO2 Max is an excellent indicator of your potential performance in endurance events.

To know more about VO2 Max: Understanding VO2 max: why is it useful?

Calories burned

Calories burned gives you the power to make informed decisions about nutrition, weight management, and performance.

To know more about Calories burned: Circular’s calories burned


SpO2 helps you keep track of your blood oxygen saturation levels. May be useful for high altitudes activities, people suffering from asthma or other oxygen conditions.

To know more about SpO2:Oxygen Saturation (SpO2) and how to use it to your advantage 

We remind you that the Circular™ ring is not a medical device and should not be used to diagnose or monitor a pathology.

Kickstarter campaign – Update #1

Kickstarter is a very interesting journey!

100% funded in under 4 hours!

200% funded in 24 hours!

0/500 ? No more VIP rewards left!

50/500 ⏳ Now switching to the early bird offer, less than 50 available.

Press coverage:

This week, Circular has been featured in some of the most influential tech outlets following our launch and demos our team had. The Circular team is thrilled to see this excitement and we would like to say thank you!

DIGITAL TRENDS: “Smart rings aren’t a new idea, but this one is arguably one of the best yet”

CORE 77: “Circular is an unobtrusive smart ring that’s easy to wear and forget about. Meanwhile, it will keep track of your activity throughout the day and night and deliver personalized recommendations to you via an accompanying app. “

TRENDHUNTER: “Due to its small and unintrusive size, many consumers prefer its minimal aesthetic to bulkier watch alternatives. The tool can be customized with interchangeable shells for different styles.”

GIZMODO: “It’s a stylish but relatively nondescript ring that could be worn in multiple scenarios without drawing too much attention.”

YANKO DESIGN: “This crystal clear focus and economy of function allows the Circular Smart Ring to be an incredibly sleek, fashion-forward wearable that bridges jewelry and tech. The lack of a screen, or a host of apps, music, images, calendars, clocks, and other ‘unnecessary fluff’ even enables the Ring to have a remarkably better battery life of 48 hours with continuous usage. “

If you haven’t secured your Circular ring yet, you can enjoy the early bird deal before it’s too late: take me to kickstarter campaign!

Tips to increase your Deep sleep

Just like REM sleep, the amount of deep sleep you need varies from person to person. It will depend on what you did during your day, on your age and other factors. For adults, deep sleep is approximately 15 to 20% of total sleep. Elderly people experience a shorter duration.

Here are so top level tips to achieve high quality and restorative deep sleep.

Sleep Cycles Circular

Get to know your sleep habits

The periods of deep sleep are the most abundant and most regenerative at the beginning of your sleep. So the goal is to fall asleep as quick as possible to spend the most time in deep sleep.

There are a lot of trackers such as the Circular Ring that you can use to know your sleep habits, the evolution of your sleep cycle and compare your nights.

Sleep every day at the same time 

By doing so, it will allow you to program your subconscious and prepare your body for falling asleep. As with everything, it will take time for your body to adapt (a few nights for most people). Once calibrated, your body will naturally warn you every night when it is time to go to bed.

Be smart about what you eat and drink

Your nutrition has a big impact on your sleep quality. Minimizing caffeine, alcohol, and nicotine before sleeping seems logical. But less known, avoid having heavy and late dinner. Sugar and carbohydrates reduce quality of deep sleep. Go for a light dinner, without quick sugars and red meat which are the foods that take the longest time to digest.

Do not eat within four to six hours prior to the time you want to sleep.

Be physically active

The more you exercise, the more your body will have to spend time in deep sleep to regenerate. It has been proven that daily exercise allows people to sleep better and stay in deep sleep longer. Do 20 to 30 minutes of exercise a day. However, exercising just before bed could interfere with your schedule. Try to exercise daily at least three hours before you go to bed.

Write your day

You can keep a daily journal by briefly describing before sleeping what happened during your day. When you write your day down, you make your brain lighter in order to enter Deep sleep faster. This will facilitate the work that is done during your REM sleep and leave more room for your deep sleep.

Avoid blue lights

Turn off the TV, smartphone, tablet, computer at least 2 hours before sleep. Or even better, keep all your electronics outside the bedroom. The light that these devices emit stimulate the brain, suppress the production of melatonin (which encourages to fall asleep), and interfere with your body’s biological clock.

Magnesium and Melatonin intake

Recent studies have shown that taking magnesium and melatonin with a dosage appropriate to your body can increase the duration of Deep sleep. See this with your doctor.

How to track how much Deep sleep you are getting?

You can use your Circular ring to know exactly how much Deep sleep you get each night. The app gives you the details of your sleep cycle including the portion of Deep sleep accordingly to your cycles, but also the amount of Deep sleep in percentage and duration of your total sleep. You can also compare your Deep sleep from night to night to monitor your evolution and compare your last night with your own average to understand your sleep.

Sleep Stages Circular

You can also read our article on Sleep better and fall asleep faster. The tips described there also apply to increase deep sleep.

If you wish to improve your REM Sleep you can also read Tips to increase your REM sleep.