High-Speed Vision-Based Haptic Sensor for Robotic Dermatological Palpation: Force Sensing Method Using Asymmetric Stiffness Coefficient Matrix
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Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
The Eurographics Association
Abstract
In this paper, we propose a vision-based haptic sensor (VHS) capable of acquiring force at the required speed for softness discrimination during palpation, along with a force measurement algorithm. Palpation requires the simultaneous acquisition of surface imagery from the affected area and haptic information, such as softness and surface texture. Additionally, the sensor must exhibit softness comparable to human skin to avoid causing discomfort to the patient. By designing a force sensor that tracks markers embedded in transparent gel using a camera, we enable the concurrent capture of visual and haptic data. An algorithm is also presented for calculating normal forces based on the extension of the markers' image plane. Accurate force modeling was achieved by training a normal force estimation model using an asymmetric stiffness coefficient matrix, which effectively mitigates cross-talk effects. Furthermore, the process was optimized by employing sparse search techniques with narrow marker search ranges between frames during high-speed imaging, enabling rapid detection of circular force markers and achieving force acquisition at 601.25 Hz. Compared to previous methods, the proposed approach offers higher measurement accuracy and speed within the force range required for palpation. It can measure at 500 Hz or higher, which is crucial for discriminating the five levels of softness important in dermatological palpation. Therefore, the proposed haptic sensor shows promise for use in robotic palpation.
Description
CCS Concepts: Human-centered computing → Haptic devices
@inproceedings{10.2312:egve.20241368,
booktitle = {ICAT-EGVE 2024 - International Conference on Artificial Reality and Telexistence and Eurographics Symposium on Virtual Environments},
editor = {Hasegawa, Shoichi and Sakata, Nobuchika and Sundstedt, Veronica},
title = {{High-Speed Vision-Based Haptic Sensor for Robotic Dermatological Palpation: Force Sensing Method Using Asymmetric Stiffness Coefficient Matrix}},
author = {Kato, Fumihiro and Shi, Miaohui and Kamishima, Kaito and Iwata, Hiroyasu},
year = {2024},
publisher = {The Eurographics Association},
ISSN = {1727-530X},
ISBN = {978-3-03868-245-5},
DOI = {10.2312/egve.20241368}
}