ARCH V1 · The Walking Simulator

Mechanism

Mechanical from the ground up.

Four precision micro linear servo actuators, vertically aligned over the calf. The mechanism is entirely mechanical, driven by coordinated pressure waves that closely match the biomechanics of a walking step.

Each of the four actuators moves on its own
The pressure sequence runs from the bottom upwards
Sensor readings decide when it engages
Quiet operation for shared spaces
Compact form, single-hand adjustment

Sensors

Pulse, tissue oxygenation, fluid balance, motion.

Sensors on the device take readings of pulse, tissue oxygenation and fluid balance. These readings are used to determine the device’s own activation timing and to display your session data in the app. They provide no health assessment, diagnosis, alert or risk evaluation.

SpO₂ % Tissue oxygenation. Optical PPG sensor.
Fluid balance 0 – 100 The fluid balance scale produced by the bioimpedance sensor.
Pulse bpm Peripheral pulse, derived from the optical PPG.
Motion internal Accelerometer and gyroscope. Stops the device for safety whenever the calf muscle has to contract, such as when you stand up or walk.

The reference thresholds appear in the app. They are the values that set the device’s activation timing, not a health indicator. Sensor readings are not medical measurements and must not be used as a basis for any diagnostic or treatment decision.

Machine Learning

Learns on the device, stays on the device.

In an automatic session, intensity adapts in real time to sensor feedback. All of that adaptive data stays on the device and on the paired phone.

Adaptive mode

Adjusts intensity in an automatic session according to your recent ones. Switch it off and the device holds its starting intensity.
Improve accuracy

Off by default. Even when you turn it on, individual sensor readings never leave your device. Only aggregate statistics are sent.
End of session

The app stores the session summary and updates the parameters for the next session.
If the link drops

The session is not cancelled. The device carries on in its current mode and buffers the data in its own memory.

Sessions

Two modes, three rhythms.

In automatic mode the sensor data is read in real time and the intensity adapts on its own. In manual mode the intensity stays where you put it.

Automatic

Sensor data is read in real time and the on-device ML model adapts the intensity. Recommended session length is 20-30 minutes.
Manual

The intensity stays fixed and only you change it. A typical session runs 10-20 minutes.

Rhythm

Gentle 20 SPM Newcomers
Standard 35 SPM Daily routine, in-flight use
Active 60 SPM Recovery

SPM is the number of walking steps the device simulates per minute.

How a session starts

From the app: pick a mode and an intensity, then press Start Session.
From the device: a short press of the button in standby starts the session at the default intensity.
With two devices: press Start Bilateral Session in the app and confirm both devices.

Without a connection

Session data is buffered in the device memory.
When the memory fills, the oldest sessions are overwritten.
The data transfers to the app on the next Bluetooth link.

Technical Specifications

ARCH V1 at a glance.

Body and dimensions

Dimensions 76 × 90 × 161 mm
Weight ~350 g
Housing ABS/PC plastic with anodised aluminium front panel
Skin contact Strap pressure only, no silicone or gel
Strap Polyester inner layer, cotton outer layer
Colours Graphite Black · Mineral Grey (coming soon)

Mechanism

Actuators 4 micro linear servo
Operating principle Peristaltic pressure sequence, bottom to top
Cycle time ~1 s
Intensity levels Gentle 20 · Standard 35 · Active 60 (steps equiv./min)
Trigger When a sensor reading moves outside its reference range

Sensors

Pulse Optical PPG
Tissue oxygenation SpO₂, optical sensor
Fluid balance Bioimpedance
Motion Accelerometer, stops the device when you stand up

Power

Battery 2,800 mAh lithium-ion
Run time ~10,000 steps equivalentup to 12 hours on the leg
Charging USB-C, standard 5 V adapter
Minimum charge per session 30%

Connectivity and app

Bluetooth BLE 5.0 with an ARCH-specific GATT profile
App iOS 17+ · Android 12+
Simultaneous devices Up to 2 (bilateral use)
Without the app Manual session from the device button

Environment

Operating temperature 0 °C – 40 °C
Storage temperature 5 °C – 40 °C
IP rating None. For indoor, low-activity use

* Figures reflect the intermittent use pattern ARCH is designed for. Continuous operation shortens run time.

Sizing

Calf circumference from 31 to 55 cm.

The leg strap comes in five sizes based on calf circumference. Measure the widest point of your calf to find the right one.

XS31 – 35 cmFine calf
S36 – 40 cmSlim calf
M41 – 45 cmAverage calf
L46 – 50 cmAthletic calf
XL51 – 55 cmPowerful calf

How to measure

Stand up and spread your weight evenly on both feet.
Measure the widest part of your calf with a flexible tape.
Keep the tape neither tight nor loose, resting lightly against the skin.
If you fall between two sizes, take the larger one.

What is in the box

ARCH V1 device
Leg strap in your chosen size
USB-C charging cable
Quick start guide, with a QR code for the digital warranty certificate

A power adapter is not included. A standard 5 V USB adapter is all you need.

Construction

Built with intention.

The two ARCH V1 finishes: Mineral Grey and Graphite Black

Skin-Contact Layer

Breathable nano-textile. Allows continuous skin contact without adhesives or gel.
Actuator Tips

Silicone-based, skin-friendly tips on each piston. They spread pressure evenly at every contact point.
Housing

Injection-moulded ABS/PC body with an anodised aluminium front panel.
Strap

Polyester inner layer, cotton outer layer against the skin. Adjustable, so it holds firm where it should and gives where it should.

App

You see what was measured.

Built separately for iOS and Android, the companion app configures the device, shows your session data and turns it into reports.

First setup
Account

You sign in with Apple or Google. The account syncs your session history across your devices. Nothing is shared without your permission.
Pairing

ARCH V1 connects over Bluetooth. You can set it up later and look around the app first.
Calibration

The device reads your calf contour, finds the zero point for the four actuators and locks that position in place. You keep your leg still through the three steps.
Ready to use

When calibration finishes, the device has learned your leg geometry. Readings and sessions open up from that point.
Everyday use
Home

Cards for oxygen, fluid balance and pulse show the current values. The top strip carries calibration state, adaptive mode and battery level.
Readings

Step counts for today, for the last seven days and for your most recent session.
Session control

Automatic or manual mode, with Gentle, Standard and Active intensity. In automatic mode the starting intensity shifts during the session. The recommended duration is 20 to 30 minutes.
Sessions

A session history you can filter by mode, period and status.
Session summary

Sensor values before and after the session, left and right separately in a bilateral session. Duration, mode and step count on the same screen.
Reports and privacy

A single-session PDF, a date-range summary and a plain-text share. You can erase all local data in one step and download every report.

iOS 17 and later (Swift/SwiftUI), Android 12 and later (Flutter). Sensor processing and adaptive ML need the app; manual mode runs on the device without it.