scholarly journals A Piezoelectric Tactile Sensor for Tissue Stiffness Detection with Arbitrary Contact Angle

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6607
Author(s):  
Yingxuan Zhang ◽  
Feng Ju ◽  
Xiaoyong Wei ◽  
Dan Wang ◽  
Yaoyao Wang
Keyword(s):  
Contact Angle ◽  
Recognition Rate ◽  
Tactile Sensor ◽  
Normal Direction ◽  
Surgical Instruments ◽  
Tissue Stiffness ◽  
Design And Optimization ◽  
Detection Model ◽  
Sensor Optimization ◽  
Simulation And Experiment

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°, 45°]. 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°, 94.1% within 45°, 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°. 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.

Simulation and experiment research of a 3D flexible tactile sensor

2011 ◽  
Vol 25 (2) ◽  
pp. 129-134
Author(s):  
Guanghui Cao ◽  
Ying Huang ◽  
Wu Zhang ◽  
Caixia Liu
Keyword(s):  
Tactile Sensor ◽  
Experiment Research ◽  
Simulation And Experiment

Construction and Reduction Methods of Web Spam Identification Index System

2019 ◽  
Vol 12 (3) ◽  
pp. 202-211
Author(s):  
Yuancheng Li ◽  
Rong Huang ◽  
Xiangqian Nie
Keyword(s):  
Index System ◽  
Rapid Development ◽  
Recognition Rate ◽  
Computing Power ◽  
Detection Model ◽  
Web Spam ◽  
Reduction Methods ◽  
Massive Scale ◽  
The Index System ◽  
The Web

Background: With the rapid development of the Internet, the number of web spam has increased dramatically in recent years, which has wasted search engine storage and computing power on a massive scale. To identify the web spam effectively, the content features, link features, hidden features and quality features of web page are integrated to establish the corresponding web spam identification index system. However, the index system is highly correlation dimension. Methods: An improved method of autoencoder named stacked autoencoder neural network (SAE) is used to realize the reduction of the web spam identification index system. Results: The experiment results show that our method could reduce effectively the index of web spam and significantly improves the recognition rate in the following work. Conclusion: An autoencoder based web spam indexes reduction method is proposed in this paper. The experimental results show that it greatly reduces the temporal and spatial complexity of the future web spam detection model.

A resonant tactile stiffness sensor for lump localization in robot-assisted minimally invasive surgery

2019 ◽  
Vol 233 (9) ◽  
pp. 909-920
Author(s):  
Yahui Yun ◽  
Yaming Wang ◽  
Hao Guo ◽  
Yaoyao Wang ◽  
Hongtao Wu ◽  
...  
Keyword(s):  
Minimally Invasive Surgery ◽  
Theoretical Model ◽  
Minimally Invasive ◽  
Resonant Frequency ◽  
Frequency Shift ◽  
Invasive Surgery ◽  
Tactile Sensor ◽  
Tissue Stiffness ◽  
Robot Assisted ◽  
Resonant Frequency Shift

A miniature resonant tactile sensor for tissue stiffness detection in robot-assisted minimally invasive surgery is proposed in this article. The proposed tactile sensor can detect tissue stiffness based on the principle of the resonant frequency shift when it contacts with tissue of different stiffness. A PZT (lead zirconate titanate) bimorph works simultaneously as the actuator and the sensing element, which is helpful for simplifying the structure. The resonant frequency shift can be deduced by measuring the electrical impedance of the PZT bimorph, since there will be an abrupt change of the impedance when resonance occurs. A unique structure of an Archimedean spiral metal sheet is introduced to restrict the outer size of the sensor within 10 mm and to keep the resonant frequency low. A theoretical model is established. Finite element method analyses are carried out to validate the working principle and it meets the theoretical model quite well. Several silicone samples are tested with the sensor and the results show that the proposed sensor is capable of measuring tissue stiffness within the range of 0–2 MPa, detecting and locating lumps inside tissue.

scholarly journals Magnetostrictive tactile sensor of detecting friction and normal force for object recognition

2020 ◽  
Vol 17 (4) ◽  
pp. 172988142093232
Author(s):  
Bing Zhang ◽  
Bowen Wang ◽  
Yunkai Li ◽  
Shaowei Jin
Keyword(s):  
Recognition Rate ◽  
Tactile Sensor ◽  
Tactile Sensing ◽  
Dynamic Force ◽  
Force Output ◽  
Tactile Sensors ◽  
Tactile Information ◽  
Normal Contact ◽  
New Type ◽  
Learning Machine

Tactile information is valuable in determining properties of objects that are inaccessible from visual perception. A new type of tangential friction and normal contact force magnetostrictive tactile sensor was developed based on the inverse magnetostrictive effect, and the force output model has been established. It can measure the exerted force in the range of 0–4 N, and it has a good response to the dynamic force in cycles of 0.25–0.5 s. We present a tactile perception strategy that a manipulator with tactile sensors in its grippers manipulates an object to measure a set of tactile features. It shows that tactile sensing system can use these features and the extreme learning machine algorithm to recognize household objects—purely from tactile sensing—from a small training set. The complex matrixes show the recognition rate is up to 83%.

Static Characteristics of Micro Disc Magneto Electric Generator – Simulation and Experiment

2013 ◽  
Vol 365-366 ◽  
pp. 356-359
Author(s):  
Lin Du ◽  
Geng Chen Shi ◽  
Jing Jing Zhao
Keyword(s):  
Finite Element ◽  
Structural Design ◽  
Experimental Result ◽  
Static Characteristics ◽  
Element Analysis ◽  
Electric Generator ◽  
Design And Optimization ◽  
Element Simulation ◽  
Simulation And Experiment ◽  
3D Software

Maxwell 3D software of finite-element analysis in electromagnetic fields is used to model and simulate the micro disc magneto electric generator. Distribution characteristics of magnetic induction are required and theoretical analysis and calculation is presented. Error between the simulation result and experimental result is about 6% which verify the rationality and accuracy of finite-element simulation. It can be used to guide the structural design and optimization of this type of generator.

scholarly journals Tactile Object Recognition for Humanoid Robots Using New Designed Piezoresistive Tactile Sensor and DCNN

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6024
Author(s):  
Somchai Pohtongkam ◽  
Jakkree Srinonchat
Keyword(s):  
Object Recognition ◽  
Humanoid Robot ◽  
Sensor Array ◽  
Recognition Rate ◽  
Tactile Sensor ◽  
Humanoid Robots ◽  
Superior Performance ◽  
Robot Hand ◽  
Sensing Element ◽  
Tactile Sensor Array

A tactile sensor array is a crucial component for applying physical sensors to a humanoid robot. This work focused on developing a palm-size tactile sensor array (56.0 mm × 56.0 mm) to apply object recognition for the humanoid robot hand. This sensor was based on a PCB technology operating with the piezoresistive principle. A conductive polymer composites sheet was used as a sensing element and the matrix array of this sensor was 16 × 16 pixels. The sensitivity of this sensor was evaluated and the sensor was installed on the robot hand. The tactile images, with resolution enhancement using bicubic interpolation obtained from 20 classes, were used to train and test 19 different DCNNs. InceptionResNetV2 provided superior performance with 91.82% accuracy. However, using the multimodal learning method that included InceptionResNetV2 and XceptionNet, the highest recognition rate of 92.73% was achieved. Moreover, this recognition rate improved when the object exploration was applied to demonstrate.

Effect of Tumor Variables and Sensor Design on the Measured Stiffness Distribution of Tumor-Embedded Tissues: A Numerical Study

2016 ◽  
Author(s):  
Yichao Yang ◽  
Zhili Hao
Keyword(s):  
Indentation Depth ◽  
Numerical Study ◽  
Tactile Sensor ◽  
Element Model ◽  
Design Parameters ◽  
Sensor Design ◽  
Tissue Stiffness ◽  
Tumor Identification ◽  
Tissue Region ◽  
Stiffness Distribution

This paper reports on a numerical study on how the measured stiffness distribution of a tumor-embedded tissue via a two-dimensional (2D) tactile sensor varies with the tumor variables (i.e., elasticity, size and depth) and the sensor design parameters. The sensor entails a polydimethylsiloxane (PDMS) microstructure embedded with a 3×3 sensing-plate/transducer array sitting on a Pyrex substrate. Pressing the sensor against a tissue region with a pre-defined indentation depth pattern, the tissue stiffness distribution is extracted from the measured slopes of the deflections of the 3×3 sensing-plate array versus the indentation depth. A finite element model (FEM) of the tissue-sensor interaction, which includes the Pyrex substrate, the microstructure, and a tumor-embedded tissue, is created using COMSOL Multiphysics. The tumor variables and the sensor design parameters are varied in the model to examine how the measured tissue stiffness distribution is affected by them. Based on the numerical results, the relation of the measured tissue stiffness distribution to the tumor variables and sensor design parameters is obtained, shedding insight on establishing a threshold on the stiffness contrast for tumor identification.

Research on the Hydrophobicity of Black Silicon Based on Virtual Process

2012 ◽  
Vol 503 ◽  
pp. 329-333
Author(s):  
Xin Li ◽  
Chen Wang ◽  
Guang Yi Sun ◽  
Xin Zhao ◽  
Hai Xia Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
3D Structure ◽  
Black Silicon ◽  
Calculating Method ◽  
Simulation And Experiment ◽  
Mems Device ◽  
The Difference ◽  
Silicon Based ◽  
Dual Scale ◽  
Virtual Process

In previous research, in order to simulate the 3D structure of MEMS device, we developed a software named Virtual Process which can help the designer to testify his/her design by comparing the simulation result with real requirements. As Virtual Process could only find out the difference in structure, we put forward a new method, which can compare the functions of the device to verify the simulation result. In this paper, we take hydrophobicity as an example to show the comparison between the results of simulation and experiment. The hydrophobicity is expressed by contact angle, which is measured by certain device in reality. In this case, this paper put forward a method to calculate the contact angle to verify the hydrophobicity of black silicon. Besides, we put forward a method combining micro/nano dual-scale DRIE to realize the simulation of black silicon before the calculation. As a result, the contact angle of black silicon between our calculating method and the actual value is only 7° .

Simulation and Experiment Research of Working Process of Exhaust Turbocharged and Intercooled Diesel Engine

2013 ◽  
Vol 744 ◽  
pp. 13-17
Author(s):  
Meng Xiang Liu ◽  
Peng Wang ◽  
Fang Yuan
Keyword(s):  
Diesel Engine ◽  
Characteristic Curve ◽  
Maximum Error ◽  
Simulation Software ◽  
Experiment Research ◽  
Working Process ◽  
Engine Exhaust ◽  
Design And Optimization ◽  
Simulating Calculation ◽  
Simulation And Experiment

In this paper, the working process mathematical models of in-cylinder of the diesel engine, exhaust turbocharger and intercooler are established, as well as the simulating model using simulation Software GT-POWER. Through parameters modification, we built the Map of efficiency characteristic curve of compressor and turbocharger. Targeted at the turbocharged intercooled diesel engine of YC4F92 type, simulating calculation and experimental verification are conducted. It turned out that the simulating value and experimental value matches well and the maximum error value is not more than 5%, which demonstrated the accuracy and reliability of the established model. The established model can works as a tool for the design and optimization of diesel engine.

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