Anandghan Waghmare
Publications

Z-Ring

CHI 2023Gestures, objects, users and passive UIs sensed from a single ring.

Z-Ring is a wearable ring that enables gesture input, object detection, user identification, and interaction with passive user interface elements using a single sensing modality and a single point of instrumentation on the finger.

It uses active electrical field sensing to detect changes in the hand's electrical impedance caused by finger motions or contact with external surfaces. In an evaluation with 21 users, Z-Ring achieved single- and two-handed gesture recognition with up to 93% accuracy; tangible input with passive touch UI elements (buttons, a continuous 1D slider and a continuous 2D trackpad) with 91.8% accuracy and under 4.4 cm and 4.1 cm mean absolute error; object recognition across six household objects with 94.5% accuracy; and user identification among 14 users with 99% accuracy.

Its sensing uses only a single co-located electrode pair for both transmitting and sensing, lending itself well to future miniaturization for on-the-go use.

Wearing Z-Ring: a thin electrode ring on the finger, connected to a small measurement unit on the wrist.
Wearing Z-Ring: a thin electrode ring on the finger, connected to a small measurement unit on the wrist.
The ring is a flexible strip with two electrodes. It measures how electricity flows through the hand, which changes as the fingers move or touch things.
The ring is a flexible strip with two electrodes. It measures how electricity flows through the hand, which changes as the fingers move or touch things.
Gestures Z-Ring recognizes as the thumb moves along the index finger: tap, double tap, long press, and left and right swipes.
Gestures Z-Ring recognizes as the thumb moves along the index finger: tap, double tap, long press, and left and right swipes.
Plain copper shapes become controls. Touching these unpowered buttons, slider and trackpad changes the hand's electrical signature, which the ring reads as input.
Plain copper shapes become controls. Touching these unpowered buttons, slider and trackpad changes the hand's electrical signature, which the ring reads as input.