Development of a Robot-assisted Online Pain Communication System using a Squeezable Tangible User Interface

Describing pain intensity constitutes an essential part of pain communication. A medical practitioner cannot depend on pain scales because of the criteria differences between the patient and caregiver. However, online pain communication is dependent on a patient’s description and an assessment on a pain scale. This paper proposes a robot-assisted pain communication system with a tangible user interface that enables non-numerical pain communication. The SQTT interface is proposed using design processes consisting of a novel squeezable input device and a twisting robot. The twisting expression of the robot represents the pain intensity, which is gauged from the squeezing power on the input device. Integrating input and output requires defining how the twisting motion of the robot is rendered from the squeezing input. An experiment was conducted to evaluate the four methods of rendering: raw, smoothing (moving average), dynamic smoothing, and updating peak. The result of a non-parametric one-way analysis of variance indicates a significant difference between the rendering methods. As a result, an appropriate rendering method is proposed based on the ranges: smoothing for mild pain, vibrating for moderate pain, and exaggerating for severe pain. In conclusion, the robot-assisted pain communication system can be implemented with intuitive interaction primitives for online context. This paper contributes a lesson in designing a robot-assisted online pain communication, which uses a new method of measuring deformation.