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.
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 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 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 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.