KeySense: LLM-Powered Hands-Down, Ten-Finger Typing on Commodity Touchscreens

TL;DR

KeySense is a software solution that enables accurate, fast, and comfortable ten-finger typing on commodity touchscreens by isolating intentional taps from noise and using an LLM decoder, improving ergonomics and performance.

Contribution

It introduces a novel software method combining cognitive-motor timing and LLM decoding to facilitate hands-down ten-finger typing on standard touchscreens.

Findings

Decoder achieves 84.8% top-1 accuracy, outperforming baselines.

Users found KeySense less physically demanding (NASA-TLX 1.5 vs 4.0).

Typing speed increased significantly with practice (28.3 WPM vs 26.2).

Abstract

Existing touchscreen software keyboards prevent users from resting their hands, forcing slow and fatiguing index-finger tapping ("chicken typing") instead of familiar hands-down ten-finger typing. We present KeySense, a purely software solution that preserves physical keyboard motor skills. KeySense isolates intentional taps from resting-finger noise using cognitive-motor timing patterns, and then uses a fine-tuned LLM decoder to convert the resulting noisy letter sequence into the intended word. In controlled component tests, the decoder substantially outperforms two statistical baselines (top-1 accuracy 84.8% vs 75.7% and 79.3%). A 12-participant study shows clear ergonomic and performance benefits: compared with the conventional hover-style keyboard, users rated KeySense as markedly less physically demanding (NASA-TLX median 1.5 vs 4.0), and after brief practice typed significantly faster (WPM 28.3 vs 26.2, p < 0.01). These results indicate that KeySense enables accurate, efficient, and comfortable ten-finger text entry on commodity touchscreens without any extra hardware.