Skip to content
All articles

The same instrument, every week

Your weight, your blood pressure and your pulse all shift with the hour and the device. Why Soma Axon reads you in one closed pod, the same way each week.

Soma Labs2 min read

Soma Axon, closed: a round cabin of oak slats on a dark stone base

Weigh yourself after dinner and again the next morning before breakfast, and the morning number is usually lower, sometimes by a kilo (about two pounds) or more. Very little about you changed overnight. The difference is mostly water and whatever you ate and drank that evening.

Most health numbers work this way. They depend on the hour, the room and the device as well as on you, which makes two readings hard to compare.

Why your readings disagree

Blood pressure is the textbook case. It tends to read higher in a doctor's office than at home, often enough that there's a name for it: the white-coat effect. Watches have their own problems. The optical sensor reads your pulse through the skin and gets less reliable when your wrist moves or the strap is loose. Even a bathroom scale can give a different number on a rug than on tile.

A clinician's hands on a blood pressure cuff wrapped around a patient's arm
At the doctor's, blood pressure often reads higher than it does at home.
An Apple Watch Ultra on a wet wrist, with an orange loop band and a compass watch face
A watch reads your pulse through the skin, so fit and movement matter.

Watches do have one big advantage. They're on you all day, so they can follow trends in your heart rate and sleep between check-ups. A yearly check-up is thorough, but a year is a long gap, and a slow change can go unnoticed for most of it.

What we mean by the same instrument

Soma Axon is designed as a closed pod you'll visit once a week for a few minutes. The light will be the same every time and so will the cameras, and you'll stand in the same spot with your hands on the same two grips. Before each reading, someone from Soma will ask how you slept, when you last ate and whether you trained, so a short night or a hard session gets noted next to the numbers.

A person stands in Soma Axon, hands on the two grips, facing a window of evening light
Hands on the grips and feet on the plate, under the same light each week. Concept render.

All that sameness is deliberate. If your resting pulse is higher than last week, we want to be able to say the change came from you and rule out the room or the equipment.

What a weekly reading gives you

After a handful of visits, Soma will have a baseline built from your own readings. A slow change, like your resting pulse creeping up over a month of short nights, should then show up as a trend you can see.

Each number will come with its margin of error. If something keeps looking off, Soma will suggest you see a clinician, since it's a wellness tool and doesn't diagnose.

Where we are

There's no pod yet, and the pictures of Axon on this blog are concept renders. We'll write here as it comes together.