Design and Simulation of Micro Tactile Sensor for Stiffness Detection of Soft Tissue with Irregular Surface

2020 ◽  
Vol 18 (3) ◽  
pp. 200-209
Author(s):  
Ahmed Fouly ◽  
Ahmed M. R. FathEl-Bab ◽  
A. A. Abouelsoud ◽  
T. Tsuchiya ◽  
O. Tabata
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Tactile Sensor ◽  
Sensor Output ◽  
Irregular Surface ◽  
Tissue Stiffness ◽  
Tactile Sensors ◽  
Element Analysis ◽  
Detailed Design ◽  
Sensor Structure

Tactile sensors become an essential part of many applications in our life. Integrating tactile sensors with surgical tools used in MIS is significant to compensate for the shortage of touch feeling of soft tissues and organs comparing with traditional surgeries. This paper presents a detailed design of a micro tactile sensor for measuring the stiffness of soft tissue with an irregular surface. The sensor consists of five cantilever springs with different stiffness. A spring in the middle has a relatively low stiffness surrounded by 4 springs have relatively equal high stiffness to compensate for the soft tissue contact error in the longitudinal and lateral directions. Sensor parameters are selected to ensure high sensitivity and linearity with taking into consideration the cross-talk effect among the sensor springs tips. A detailed design of the sensor structure in the microscale is conducted based on some constraints related to MEMS fabrication. A finite element analysis (FEA) of the sensor structure is conducted to evaluate sensor structure performance using CoventorWare software. Then, an FEA for the piezo-resistors, as a signal transduction method, is conducted which maps the sensor output to an electrical signal. The results prove that the sensor can differentiate among different soft-tissue stiffness within the selected range independent of the applied distance between the sensor and the tissue with an error below 3% even with inclination angle between the sensor and the tissue ±3°. Furthermore, a linear performance has been achieved between the soft-tissue stiffness and the sensor output.

scholarly journals DIGITAL RECONSTRUCTION OF SOFT-TISSUE STRUCTURES IN FOSSILS

2016 ◽  
Vol 22 ◽  
pp. 101-117 ◽  
Author(s):  
Stephan Lautenschlager
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Analytical Techniques ◽  
Computational Imaging ◽  
Whole Body ◽  
Element Analysis ◽  
Digital Reconstruction ◽  
New Information ◽  
Tissue Structures

AbstractIn the last two decades, advances in computational imaging techniques and digital visualization have created novel avenues for the study of fossil organisms. As a result, paleontology has undergone a shift from the pure study of physically preserved bones and teeth, and other hard tissues, to using virtual computer models to study specimens in greater detail, restore incomplete specimens, and perform biomechanical analyses. The rapidly increasing application of these techniques has further paved the way for the digital reconstruction of soft-tissue structures, which are rarely preserved or otherwise available in the fossil record. In this contribution, different types of digital soft-tissue reconstructions are introduced and reviewed. Provided examples include methodological approaches for the reconstruction of musculature, endocranial components (e.g., brain, inner ear, and neurovascular structures), and other soft tissues (e.g., whole-body and life reconstructions). Digital techniques provide versatile tools for the reconstruction of soft tissues, but given the nature of fossil specimens, some limitations and uncertainties remain. Nevertheless, digital reconstructions can provide new information, in particular if interpreted in a phylogenetically grounded framework. Combined with other digital analytical techniques (e.g., finite element analysis [FEA], multibody dynamics analysis [MDA], and computational fluid dynamics [CFD]), soft-tissue reconstructions can be used to elucidate the paleobiology of extinct organisms and to test competing evolutionary hypotheses.

Micro Capacitive Tactile Sensor for Contact Loads

2008 ◽  
Vol 33-37 ◽  
pp. 931-936 ◽  
Author(s):  
Chieh Tang Chuang ◽  
Rong Shun Chen
Keyword(s):  
High Sensitivity ◽  
Tactile Sensor ◽  
Force Transmission ◽  
Element Analysis ◽  
Deep Reactive Ion Etching ◽  
Normal Forces ◽  
Contact Loads ◽  
Capacitance Variation ◽  
Sensor Structure ◽  
The Finite Element Analysis

This paper presents a high sensitivity micro capacitive tactile sensor that can detect normal forces which is fabricated using deep reactive ion etching (DRIE) bulk silicon micromachining. The tactile sensor consists of a force transmission plate, a symmetric suspension system, and comb electrodes. The sensing character is based on the changes of capacitance between coplanar sense electrodes and it can reach the aim of large sensing range. High sensitivity is achieved by using the high aspect ratio comb electrodes with narrow comb gaps and large overlap areas. In this paper, the sensor structure is designed, the capacitance variation of the proposed device is analyzed, and the finite element analysis of mechanical behavior of the structures is performed.

scholarly journals Plantar soft tissues and Achilles tendon thickness and stiffness in people with diabetes: a systematic review

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Benedictine Yen Chen Khor ◽  
James Woodburn ◽  
Lisa Newcombe ◽  
Ruth Barn
Keyword(s):  
Systematic Review ◽  
Soft Tissue ◽  
Achilles Tendon ◽  
Methodological Quality ◽  
Soft Tissues ◽  
Tissue Stiffness ◽  
Tissue Thickness ◽  
Tendon Stiffness ◽  
Structural Differences ◽  
Tendon Thickness

Abstract Background Diabetes mellitus is associated with changes in soft tissue structure and function. However, the directionality of this change and the extent to which either tissue thickness or stiffness contributes to the pathogenesis of diabetes-related foot ulcerations is unclear. Hence, this systematic review aims to summarise the existing evidence for soft tissue structural differences in the feet of people with and without diabetes. Methods In compliance with MOOSE and PRISMA guidelines, AMED, CINAHL, MEDLINE, ProQuest Health & Medical Collection, ProQuest Nursing & Allied Health Database, and Web of Science electronic databases were systematically searched for studies published from database inception until 1st October 2020 [Prospero CRD42020166614]. Reference lists of included studies were further screened. Methodological quality was appraised using a modified critical appraisal tool for quantitative studies developed by McMaster University. Results A total of 35 non-randomised observational studies were suitable for inclusion. Within these, 20 studies evaluated plantar tissue thickness, 19 studies evaluated plantar tissue stiffness, 9 studies evaluated Achilles tendon thickness and 5 studies evaluated Achilles tendon stiffness outcomes. No significant differences in plantar tissue thickness were found between people with and without diabetes in 55% of studies (11/20), while significantly increased plantar tissue stiffness was found in people with diabetes in 47% of studies (9/19). Significantly increased Achilles tendon thickness was found in people with diabetes in 44% of studies (4/9), while no significant differences in Achilles tendon stiffness were found between people with and without diabetes in 60% of studies (3/5). Conclusions This systematic review found some evidence of soft tissue structural differences between people with and without diabetes. However, uncertainty remains whether these differences independently contribute to diabetes-related foot ulcerations. The heterogeneity of methodological approaches made it difficult to compare across studies and methodological quality was generally inadequate. High-quality studies using standardised and validated assessment techniques in well-defined populations are required to determine more fully the role of structural tissue properties in the pathogenesis of diabetes-related foot ulcerations.

A Novel Tactile Sensor Design for Stiffness Detection of Soft Tissues

2010 ◽  
Author(s):  
Ahmed M. R. Fath El Bab ◽  
Khaled I. E. Ahmed
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Simulation Model ◽  
Soft Tissues ◽  
Tactile Sensor ◽  
Sensor Design ◽  
Contact Conditions ◽  
Sensor Performance ◽  
Element Simulation ◽  
Different Tissues

A novel tactile sensor design for stiffness detection of soft tissues is proposed aiming to get output readings uninfluenced of the contact conditions. The sensor principle is based on the concept of applying two springs, with considerably different stiffnesses, to soft tissue for stiffness detection. The sensor consists of two coaxial diaphragms with contact mesa to work as two different springs. The sensor mesas are designed in circular shape to compensate the error caused by the pushing distances between the sensor and the soft tissue. A finite element simulation model is developed to investigate the sensor performance. The results show that the sensor can successfully distinguish between different tissues with close stiffnesses independently of the pushing distance between the sensor and the tissue. Moreover the sensor shows good output linearity when measure different tissue stiffnesses.

scholarly journals Flexible mechanical metamaterials enabling soft tactile sensors with multiple sensitivities at multiple force sensing ranges

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alireza Mohammadi ◽  
Ying Tan ◽  
Peter Choong ◽  
Denny Oetomo
Keyword(s):  
Degrees Of Freedom ◽  
Force Measurement ◽  
Design Procedure ◽  
Tactile Sensor ◽  
Design Parameters ◽  
Force Sensing ◽  
Tactile Sensors ◽  
Human Machine Interaction ◽  
Mechanical Metamaterials ◽  
Sensor Structure

AbstractThe majority of existing tactile sensors are designed to measure a particular range of force with a fixed sensitivity. However, some applications require tactile sensors with multiple task-relevant sensitivities at multiple ranges of force sensing. Inspired by the human tactile sensing capability, this paper proposes a novel soft tactile sensor based on mechanical metamaterials which exhibits multiple sensitivity regimes due to the step-by-step locking behaviour of its heterogenous multi-layered structure. By tuning the geometrical design parameters of the collapsible layers, each layer experiences locking behaviour under different ranges of force which provides different sensitivity of the sensor at different force magnitude. The integration of a magnetic-based transduction method with the proposed structure results in high design degrees of freedom for realising the desired contact force sensitivities and corresponding force sensing ranges. A systematic design procedure is proposed to select appropriate design parameters to produce the desired characteristics. Two example designs of the sensor structure were fabricated using widely available benchtop 3D printers and tested for their performance. The results showed the capability of the sensor in providing the desired characteristics in terms of sensitivity and force range and being realised in different shapes, sizes and number of layers in a single structure. The proposed multi-sensitivity soft tactile sensor has a great potential to be used in a wide variety of applications where different sensitivities of force measurement is required at different ranges of force magnitudes, from robotic manipulation and human–machine interaction to biomedical engineering and health-monitoring.

Comparison between 2D and 3D Simulation of Contact of Two Deformable Axisymmetric Bodies

2020 ◽  
Vol 21 (2) ◽  
pp. 123-133
Author(s):  
Marat Dosaev ◽  
Vitaly Samsonov ◽  
Vladislav Bekmemetev
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Tactile Sensor ◽  
3D Models ◽  
The Finite Element Method ◽  
Current Version ◽  
Local Stiffness ◽  
2D And 3D ◽  
Axisymmetric Bodies ◽  
Range Of Values

AbstractA portable pneumatic video-tactile sensor for determining the local stiffness of soft tissue and the methodology for its application are considered. The expected range of local elastic modulus that can be estimated by the sensor is 100 kPa–1 MPa. The current version of the device is designed to determine the characteristics of tissues that are close in mechanical properties to the skin with subcutis and muscles. A numerical simulation of the contact between the sensor head and the soft tissue was performed using the finite-element method. Both 2D and 3D models were developed. Results of experiments with device prototype are used for approval of adequacy of mathematical modelling in case of large deformations. Simulation results can be used to create soft tissue databases, which will be required to determine the local stiffness of soft tissues by the sensor. 2D model proved to be more efficient for the chosen range of values of local stiffness of soft tissues.

Imaging Features of Primary Tumors of the Hand

2020 ◽  
Vol 16 ◽  
Author(s):  
Filippo Boriani ◽  
Edoardo Raposio ◽  
Costantino Errani
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Epithelioid Sarcoma ◽  
Case Series ◽  
Malignant Neoplasm ◽  
Benign Tumors ◽  
Imaging Features ◽  
Primary Tumors ◽  
Therapeutic Decisions ◽  
Tumors Of The Hand

: Musculoskeletal tumors of the hand are a rare entity and are divided into skeletal and soft tissue tumors. Either category comprises benign and malignant or even intermediate tumors. Basic radiology allows an optimal resolution of bone and related soft tissue areas, ultrasound and more sophisticated radiologic tools such as scintigraphy, CT and MRI allow a more accurate evaluation of tumor extent. Enchondroma is the most common benign tumor affecting bone, whereas chondrosarcoma is the most commonly represented malignant neoplasm localized to hand bones. In the soft tissues ganglions are the most common benign tumors and epithelioid sarcoma is the most frequently represented malignant tumor targeting hand soft tissues. The knowledge regarding diagnostic and therapeutic management of these tumors is often deriving from small case series, retrospective studies or even case reports. Evidences from prospective studies or controlled trials are limited and for this lack of clear and supported evidences data from the medical literature on the topic are controversial, in terms of demographics, clinical presentation, diagnosis prognosis and therapy.The correct recognition of the specific subtype and extension of the tumor through first line and second line radiology is essential for the surgeon, in order to effectively direct the therapeutic decisions.

scholarly journals A Vibrissa-Inspired Highly Flexible Tactile Sensor: Scanning 3D Object Surfaces Providing Tactile Images

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1572
Author(s):  
Lukas Merker ◽  
Joachim Steigenberger ◽  
Rafael Marangoni ◽  
Carsten Behn
Keyword(s):  
Steel Wire ◽  
Sense Organ ◽  
Tactile Sensor ◽  
Tactile Sensors ◽  
Measuring Device ◽  
3D Object ◽  
Torque Transducer ◽  
Sense Of Touch ◽  
Important Basis ◽  
Support Reactions

Just as the sense of touch complements vision in various species, several robots could benefit from advanced tactile sensors, in particular when operating under poor visibility. A prominent tactile sense organ, frequently serving as a natural paragon for developing tactile sensors, is the vibrissae of, e.g., rats. Within this study, we present a vibrissa-inspired sensor concept for 3D object scanning and reconstruction to be exemplarily used in mobile robots. The setup consists of a highly flexible rod attached to a 3D force-torque transducer (measuring device). The scanning process is realized by translationally shifting the base of the rod relative to the object. Consequently, the rod sweeps over the object’s surface, undergoing large bending deflections. Then, the support reactions at the base of the rod are evaluated for contact localization. Presenting a method of theoretically generating these support reactions, we provide an important basis for future parameter studies. During scanning, lateral slip of the rod is not actively prevented, in contrast to literature. In this way, we demonstrate the suitability of the sensor for passively dragging it on a mobile robot. Experimental scanning sweeps using an artificial vibrissa (steel wire) of length 50 mm and a glass sphere as a test object with a diameter of 60 mm verify the theoretical results and serve as a proof of concept.

scholarly journals Developing a Quantifying Device for Soft Tissue Material Prop-Erties around Lumbar Spines

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 67
Author(s):  
Song Joo Lee ◽  
Yong-Eun Cho ◽  
Kyung-Hyun Kim ◽  
Deukhee Lee
Keyword(s):  
Lumbar Spine ◽  
Soft Tissue ◽  
Young’S Modulus ◽  
Viscoelastic Properties ◽  
Soft Tissues ◽  
Young's Modulus ◽  
Strain Curve ◽  
Stress And Strain ◽  
Commercial Device ◽  
Tissue Material

Knowing the material properties of the musculoskeletal soft tissue could be important to develop rehabilitation therapy and surgical procedures. However, there is a lack of devices and information on the viscoelastic properties of soft tissues around the lumbar spine. The goal of this study was to develop a portable quantifying device for providing strain and stress curves of muscles and ligaments around the lumbar spine at various stretching speeds. Each sample was conditioned and applied for 20 repeatable cyclic 5 mm stretch-and-relax trials in the direction and perpendicular direction of the fiber at 2, 3 and 5 mm/s. Our device successfully provided the stress and strain curve of the samples and our results showed that there were significant effects of speed on the young’s modulus of the samples (p < 0.05). Compared to the expensive commercial device, our lower-cost device provided comparable stress and strain curves of the sample. Based on our device and findings, various sizes of samples can be measured and viscoelastic properties of the soft tissues can be obtained. Our portable device and approach can help to investigate young’s modulus of musculoskeletal soft tissues conveniently, and can be a basis for developing a material testing device in a surgical room or various lab environments.

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