All projects
Research hardwareMotor Control

ErgoDigit Flex

An ergonomic, plug-and-play device for measuring the force of every finger on both hands.

ErgoDigit Flex lets researchers record how hard each of the ten fingers presses, millisecond by millisecond, while participants rest their hands comfortably on a contoured support. It was designed and built in the Diedrichsen Lab at Western University to study how we learn and control skilled hand movements.

Get in touch View in 3D
ErgoDigit Flex hand unit on a desk: a contoured grey hand rest with four finger keys and a thumb key on the side

Explore in 3D

Render of the ErgoDigit Flex hand unit

Drag to rotate · scroll or pinch to zoom Interactive model coming soon

What it is

The system has two hand units, one for each hand, and a compact amplifier unit that connects them to an ordinary laptop or desktop over a single USB cable. Each hand unit is shaped so the hand rests on it naturally, with a key beneath every fingertip.

The measurement is isometric: the keys barely move, so what is recorded is pure force rather than movement. That makes it well suited to studying fine control of individual fingers, and how that control changes with practice.

Experiments are written in PsychoPy, the free, open-source toolkit many labs already use, and run on Windows, macOS or Linux. The whole kit is light enough to carry, so it works just as well in a fixed lab setup as it does at a bedside.

What it's used for

Finger sequences

Pressing fingers one after another in a set order, to track how speed and accuracy improve as a sequence is learned.

Multi-finger chords

Pressing several fingers at once in a specific pattern, much like learning a new chord on the guitar.

Finger individuation

Pressing with one finger while keeping the others still, a common measure in research on dexterity and motor recovery.

Two-handed tasks

All ten fingers are recorded at the same time, so tasks can involve both hands and how they work together.

At a glance

Channels
10 fingersFive per hand, one key per finger
Measures
Finger forceIsometric: the keys barely move
Force range
Up to ~18 NThree selectable ranges per finger
Sampling rate
Up to 500 HzA new reading every 2 ms
Latency
~13 msFrom key press to screen, best case
Connection
One USB cableWindows, macOS or Linux
Software
PsychoPyFree and open source
Hand unit
20 × 16 × 6.4 cmLeft and right, mirror images

What's included

  • Two hand units, one for each hand
  • Amplifier unit that connects them to the computer
  • Two padded forearm rests for long sessions
  • Two mounting brackets to hold the hand units in place
  • All cables: hand units, USB and power
  • Experiment code to get started in PsychoPy

Interested in ErgoDigit Flex?

If you'd like to learn more, or to purchase or build one for your lab, email me at aghavamp@uwo.ca.

Email me