CaRing: Preventing Carpal Tunnel Syndrome based on Daily Activities from Always-Available Input Device

2026-08-06

AI Summary

Prolonged mouse usage is a known risk factor for carpal tunnel syndrome, yet existing software-based or wrist-worn solutions struggle to accurately detect fine-grained finger movements. To address this limitation, this work proposes CaRing—a smart ring worn at the base of the index finger that leverages an optical flow sensor to capture finger displacement. By integrating a displacement accumulation algorithm with a session-adaptive zero-point calibration technique, CaRing enables real-time, high-precision detection of mouse usage onset and offset without requiring user-specific calibration parameters. In experiments involving 10 participants across 35 sessions, approximately 90% of mouse usage events were accurately captured within ±2 seconds of ground-truth annotations, substantially outperforming conventional approaches.

Abstract

We present CaRing, a ring worn on the base knuckle of the index finger, a wearable system for detecting the start and end of mouse use to help prevent Carpal Tunnel Syndrome, in which the damage to the median nerve is permanent. CaRing senses finger movement, which neither a software timer nor a wrist-worn device detects. The displacement reported by an optical flow sensor is accumulated into a running value, then a zero point is measured while the hand rests on the desk at the start of each session. With this formulation, the start and end thresholds are expressed relative to the session's zero point. CaRing does not introduce any per-user parameter. We empirically demonstrate that approximately $90\%$ of start and end events are detected within two seconds of the researcher's label, using 35 recordings and a lab study with ten users.

Problem

• Carpal Tunnel Syndrome
• mouse use detection
• wearable system
• finger movement sensing
• input device interaction

Innovation

• wearable sensing
• optical flow sensor
• carpal tunnel prevention
• zero-point calibration
• finger movement detection