HiFinger: One-Handed Text Entry Technique for Virtual Environments Based on Touches between Fingers

Abstract

We present a text entry technique called HiFinger, which is an eyes-free, one-handed wearable text entry technique for immersive virtual environments by thumb-to-fingers touch. This technique enables users to input text quickly, accurately, and comfortably with the sense of touch and a two-step input mode. It is especially suitable for mobile scenarios where users need to move (such as walking) in virtual environments. Various input signals can be triggered by moving the thumb towards ultra-thin pressure sensors placed on other fingers. After acquiring the comfort range of the touch between the thumb and other fingers, six placement modes for text entry are designed and tested, resulting in an optimal placement mode that leverages six pressure sensors for the text entry and two for the control function. A three-day study is conducted to evaluate the proposed technique, and experimental results show that novices can achieve an average text entry efficiency of 9.82 words per minute (WPM) in virtual environments based on head-mounted displays after a training period of 25 min.

M[eye]cro

“…Thumb-to-finger gestures are microgestures involving a contact between the thumb and another hand part [41]. Several studies assess the comfort of finger parts on which to perform thumb-to-finger gestures [18,21,36,46]. Results show that comfort gradually decreases from the index finger to the pinky, however, the index and middle fingers are close in terms of comfort compared to the other fingers.…”

“…To recognize thumb-to-finger gestures several approaches use cameras, however, they require calibration and they suffer from occlusion (i.e occlusion of joints and finger segments) [29,36,41]. Other approaches equip the hand with touch sensors, which seem to be a more reliable and easy to design approach [21,28,45,52,56,57]. This is the chosen method for our technique M[eye]cro.…”

“…However, this technique was not quantitatively compared to another technique. The other techniques were designed for text entry using thumb-to-finger gestures [21,28,49,52,55]. All these techniques were compared to standard keyboards, but most importantly none were tested in a multitasking context.…”

“…We placed 18.5mm wide circular Force-Sensitive Resistors (FSR) 4 to detect thumb taps on different parts of the left hand. Following comfort and preference recommendations of previous studies [18,21,36,46], we placed a total of 8 sensors: three sensors on each phalanx inner side of the index and middle fingers, one sensor on the ring finger nail and one sensor on the lateral side of the upper index finger phalanx 5 . We also used flex sensors 6 placed on the back of the index and middle fingers sensing how bent fingers are.…”

Investigating the Performance of Gesture-Based Input for Mid-Air Text Entry in a Virtual Environment: A Comparison of Hand-Up versus Hand-Down Postures

“…Compared with other interactive tasks in a virtual environment, text input is a more complex and refined task. Prior researchers have investigated various interaction methods for typing in VR, such as wearable devices [ 1 ], VR controllers [ 2 , 3 ], head and gaze devices [ 4 ], pens and tablets [ 5 ], virtual touchscreens, and augmented reality keyboard [ 6 , 7 ], speech-to-text input device [ 8 ], and hands or gestures [ 9 , 10 ].…”