Human–Computer Interface Controlled by the Lip

Abstract

Lip control system is an innovative human-computer interface specially designed for people with tetraplegia. This paper presents an evaluation of the lower lip potential to control an input device, according to Fitts' law (ISO/TS 9241-411:2012 standard). The results show that the lower lip throughput is comparable with the thumb throughput using the same input device under the same conditions. These results establish the baseline for future research studies about the lower lip capacity to operate a computer input device.

Facial Position and Expression-Based Human–Computer Interface for Persons With Tetraplegia

“…3) Mechanical Motion Based ATs: With the mechanical motion based ATs, the user controls a computer via the switches or analog devices, such as sip-and-puff [10], mouth stick/pad [11] and lip control system [12]. One of the problems of sip-and-puff and mouth stick/pad interfaces is the hygienic issue.…”

“…One of the problems of sip-and-puff and mouth stick/pad interfaces is the hygienic issue. To address the hygienic issue, the authors of [12] proposed a Lip Control System (LCS). However, LCS requires wearing an accessory in front the lip.…”

“…7(b). Each subject was instructed to move the cursor to the centre of the target as quickly and precisely as possible, and then to select the pointing target as quickly as possible (click the left button using the mouse, dwell on the pointing target in the monitor for 500 ms, as suggested in [13], [12], using FM or Camera Mouse). After the tapping task, each subject was interviewed and given a questionnaire, which was defined in ISO/TS 9241-411 standard to evaluate the comfort in the use of interfaces and was adapted to involve the specific body parts used during the experiments.…”

“…7(b)) are used to generate six D-W pair conditions. Table III shows the design values, which include all the conditions for multi-directional tasks of [1] and [12]. Each D-W condition randomly appeared during experiments.…”

“…2) Performance Metrics: According to ISO/TS 9241-411 standard, the metric for comparison is throughput (T P ), which includes both the accuracy and speed of user operation performance. We used one additional metric, i.e., Task Completion Time (T CT ) as used in [1], [8], [12].…”