Action Augmentation of Tactile Perception for Soft-Body Palpation

Luca Scimeca,Perla Maiolino,Fumiya Iida,Thrishantha Nanayakkara,Josie Hughes,Liang He

doi:10.1089/soro.2020.0129

Luca Scimeca, Perla Maiolino + Show 4 more

Open Access

https://doi.org/10.1089/soro.2020.0129

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Abstract

Medical palpation is a diagnostic technique in which physicians use the sense of touch to manipulate the soft human tissue. This can be done to enable the diagnosis of possibly life-threatening conditions, such as cancer. Palpation is still poorly understood because of the complex interaction dynamics between the practitioners' hands and the soft human body. To understand this complex of soft body interactions, we explore robotic palpation for the purpose of diagnosing the presence of abnormal inclusions, or tumors. Using a Bayesian framework for training and classification, we show that the exploration of soft bodies requires complex, multi-axis, palpation trajectories. We also find that this probabilistic approach is capable of rapidly searching the large action space of the robot. This work progresses “robotic” palpation, and it provides frameworks for understanding and exploiting soft body interactions.

Highlights

The palpation of soft bodies is a complex medical procedure where physicians palpate the human body for the diagnosis of abnormalities.[1,2] Practitioners use their hands to explore and feel for abnormalities within the soft tissue of the patient’s body, exploiting the physical structure and the sensing capabilities of the human hand.[3]
We examine 64 different palpation trajectories, and we analyze how they influence the separation of probability density functions (PDFs)
Medical palpation is an impactful preliminary diagnosis tool that is used widely by primary care physicians, yet it is extremely challenging for a robot to perform due to the complexity of the interactions

Summary

Introduction

The palpation of soft bodies is a complex medical procedure where physicians palpate the human body for the diagnosis of abnormalities.[1,2] Practitioners use their hands to explore and feel for abnormalities within the soft tissue of the patient’s body, exploiting the physical structure and the sensing capabilities of the human hand.[3] This action is widely used for the initial detection and screening of abnormalities within the body, aiding the diagnosis of conditions, including cancer,[4] abdominal aortic aneurysm,[5] appendicitis,[6] and others.[7,8,9] The complexity of this important procedure arises from the complex motions of the practitioner’s hand that are in contact with the interacting layers of soft tissues of the human body, which can have many (or infinite) degrees of freedom. The use of probes with variable mechanical impedance has been found to improve lumps and tumor detection,[15] and the importance of sensory-motor coordination has been shown across a number of medical applications.[16,17,18] One of the key enabling technologies to improve robotic palpation capabilities is tactile sensing,[19] which has led to the in-depth study of the use of tactile sensors for tumor localization.[20,21,22,23,24,25,26] Robotics research has attempted the development of technologies for medical teleoperation[27,28,29,30] and medical training, such as haptic palpation training systems,[31,32,33,34] and virtual reality training systems.[7,35,36]

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