Title
A Piezoelectric Tactile Sensor For Tissue Stiffness Detection With Arbitrary Contact Angle
Abstract
In this paper, a piezoelectric tactile sensor for detecting tissue stiffness in robot-assisted minimally invasive surgery (RMIS) is proposed. It can detect the stiffness not only when the probe is normal to the tissue surface, but also when there is a contact angle between the probe and normal direction. It solves the problem that existing sensors can only detect in the normal direction to ensure accuracy when the degree of freedom (DOF) of surgical instruments is limited. The proposed senor can distinguish samples with different stiffness and recognize lump from normal tissue effectively when the contact angle varies within [0 degrees, 45 degrees]. These are achieved by establishing a new detection model and sensor optimization. It deduces the influence of contact angle on stiffness detection by sensor parameters design and optimization. The detection performance of the sensor is confirmed by simulation and experiment. Five samples with different stiffness (including lump and normal samples with close stiffness) are used. Through blind recognition test in simulation, the recognition rate is 100% when the contact angle is randomly selected within 30 degrees, 94.1% within 45 degrees, which is 38.7% higher than the unoptimized sensor. Through blind classification test and automatic k-means clustering in experiment, the correct rate is 92% when the contact angle is randomly selected within 45 degrees. We can get the proposed sensor can easily recognize samples with different stiffness with high accuracy which has broad application prospects in the medical field.
Year
DOI
Venue
2020
10.3390/s20226607
SENSORS
Keywords
DocType
Volume
tactile sensor, piezoelectric sensor, stiffness detection, arbitrary contact angle
Journal
20
Issue
ISSN
Citations 
22
1424-8220
0
PageRank 
References 
Authors
0.34
0
5
Name
Order
Citations
PageRank
Yingxuan Zhang101.35
Feng Ju255.47
Xiaoyong Wei301.01
Dan Wang46812.92
Yaoyao Wang5219.30