How Mere reads your pulse wave

Every heartbeat sends a pulse wave to your fingertips. Mere reads that wave each night and learns what normal looks like for you. Reading its shape is often called pulse wave analysis. Here is how, and where the evidence ends.

How the ring reads your pulse with light (PPG)

The ring shines light into your finger and measures how much comes back. With each beat, the vessels under the ring fill a little and absorb a little more light. Traced over time, that becomes a wave. The method is called photoplethysmography, or PPG, and clinical devices have relied on it for decades (Allen, 2007). See everything the ring reads and its full specifications.

Mere uses three kinds of light: green, red and infrared. Green tracks each beat closely. In one study, pulse rates from green light matched an ECG in cold, normal and hot rooms, while infrared was less reliable in the cold (Maeda et al., 2011). Red and infrared reach deeper. Oxygen-rich and oxygen-poor blood absorb them differently, so comparing the two estimates blood oxygen (Allen, 2007). The ring also tracks heart rate, heart rate variability, movement and sleep.

The four parts of a pulse wave

A heart rate is one number. The wave has a shape, and research suggests the shape carries more (Elgendi, 2012). A pulse is a sentence, not a sum walks through each part.

• Rise. The upstroke (the systolic upstroke), as your heart pushes each beat out.
• Peak. How much the vessels under the ring swell with each beat.
• Notch. A small dip on the way down, known as the dicrotic notch. It lines up with the closing of the aortic valve (Elgendi, 2012).
• Echo. A softer second wave (the diastolic peak, or reflected wave): the pulse reflected back through your arteries. With age, the echo tends to return sooner (Millasseau et al., 2002).

Models trained on smartwatch PPG from about 141,000 people learned to encode age, sex and health information from the signal (Abbaspourazad et al., 2024). Their result, not ours, but it supports reading shape, not just speed.

Why Mere learns your own normal over 14 nights

Published ranges for heart rate variability shift with age, sex and how long the recording runs (Shaffer & Ginsberg, 2017). An average describes a crowd. Mere learns one person. Why your normal is yours.

For 14 nights, Mere mostly learns. One night can mislead: a late dinner, a glass of wine, a hard workout. Two weeks spans weekdays and weekends, twice. After that, each night is read against your own range, so a change means a change for you.

How pulse features map to nine wellness patterns

Traditional pulse reading describes the pulse by its qualities: how deep, how fast, how strong, how taut. Mere translates that centuries-old vocabulary into features of the wave, such as timing, height, slope, notch and echo, and how each shifts overnight. The pulse model behind it, five years in development, learns those features from data. A short history of reading the pulse.

Mere's nine patterns are drawn from a modern nine-type body constitution framework with roots in traditional wisdom. The free Reading suggests where you start; the ring confirms or changes it, night by night. You see the nine in plain English: Steady, Wired, Slow start, Drained, Tense, Heavy, Overloaded, Stiff and Sensitive. Each reflects how your body has been running lately, not what is wrong. Meet the nine.

How the Formula is designed

The Mere Formula is in development and will launch after the ring. It will be optional: a Day pod with breakfast and a Night pod after dinner, designed to three rules.

• Timed for absorption. In one trial in healthy older adults, a single dose of vitamin D3 taken with a meal containing fat produced peak blood levels about a third higher than the same dose with a fat-free meal (Dawson-Hughes et al., 2015). The trial tested D3; K2 is also fat-soluble. So any D3 or K2 will go in the Day pod, to take with a breakfast that includes some fat. More on timing.
• Under the upper limits. Every vitamin and mineral with an official upper limit (the National Academies' Tolerable Upper Intake Level) will stay under it, counting both pods and the supplements you tell us you take. Pregnant, nursing or on medication? Ask your doctor first.
• Rebuilt every 30 days. From your ring data, check-ins and any labs you add. Every ingredient, form and dose will be named, and you will see what changes, and why, before each box ships.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

What we do not claim

Mere is a wellness product. It does not diagnose, detect, treat, cure or prevent any condition, and a pattern is not a diagnosis. The ring notices. Your doctor decides.

The research here is other people's work, cited so you can read it yourself. None of it measures Mere. Mere itself has not yet been tested in published studies. When we have results, we will share them here.

Questions about the science? Get in touch. To hear when the free Reading opens, join the founding list.