Applying electric field sensing to human-computer interfaces

TLDR

The paper investigates a non‑contact human‑computer interface sensor that uses electric field interaction with the human body. It examines two sensing modes—shunting an external electric field to ground through the body and transmitting it through the body to stationary receivers—and presents systems such as a finger mouse, occupancy‑aware rooms, and people‑sensing furniture, along with empirical and analytical methods for converting sensor data into position information. The sensors achieve milliwatt power consumption, millimeter resolution, a few dollars per channel cost, millisecond latency, 1 kHz update rate, >72 dB noise immunity, and are unaffected by clothing, texture, or reflectivity, operating from microns to meters, and the study also demonstrates passive‑material haptic feedback.

Abstract

A non-contact sensor based on the interaction of a person with electric fields for human-computer interface is investigated. Two sensing modes are explored: an external electric field shunted to ground through a human body, and an external electric field transmitted through a human body to stationary receivers. The sensors are low power (milliwatts), high resolution (millimeter) low cost (a few dollars per channel), have low latency (millisecond), high update rate (1 kHz), high immunity to noise (>72 dB), are not affected by clothing, surface texture or reflectivity, and can operate on length scales from microns to meters. Systems incorporating the sensors include a finger mouse, a room that knows the location of its occupant, and people-sensing furniture. Haptic feedback using passive materials is described. Also discussed are empirical and analytical approaches to transform sensor measurements into position information.