WrisText: One-handed Text Entry on Smartwatch using Wrist Gestures

Motivation

Text entry is a common and important task in daily mobile life, comprising of approximately 40% of mobile activity. However, entering text on a smartwatch is challenging because of the small form factor and its wearable context. One of the most commonly observed problems is the need to use one or both hands for a task (e.g. driving or walking while holding an umbrella or shopping bags). This is cumbersome in the context of smartwatches, as a user is required to interrupt their ongoing task to enter text, which reduces the purposefulness of smartwatches, as they are predominantly valuable for accessing information while on-the-go.

How WrisText Works

WrisText is a one-handed text entry technique for smartwatches using the wrist’s joystick-like motion. With it, a user whirls the wrist of the same-side hand to strike directional marks to select keys on a circular keyboard on a smartwatch. To enter “you”, a user selects [YZAB] -> [ONML] -> [TUVWX] by striking the wrist N -> S -> W. The entered text and suggested auto-complete are shown on the screen.

Enter "Y"	Enter "O"	Enter "U"	Select "YOU"

Prototype

Our hardware is similar to the one presented in WristWhirl. The device contains a Ticwatch 2 and a plastic watch strap augmented with 12 infrared proximity sensors (LITON LTE-301 & 302) placed approximately 0.4 cm apart from each other. We connected the sensors to an Arduino DUE microcontroller, which is connected to a laptop reading sensor data at a speed of 9600 Hz. Data is then sent and visualized on the Ticwatch 2 through Bluetooth. Pinch and rub is detected using piezo vibration sensors placed inside the wrist strap.

Prototype	Sensors

Selected Press Coverage

EurekAlert: Dartmouth College brings smartwatch innovations to CHI2018

QUARTZ: The newest idea for smartwatch texting looks just like your old flip phone

Weather Science: Smartwatch Enters Text with Wrist Movements

Discovery's Daily Planet: Replies from the wrist