Silicone-Based Tissue-Mimicking Phantom for Needle Insertion Simulation

2014 ◽  
Vol 8 (2) ◽  
Author(s):  
Yancheng Wang ◽  
Bruce L. Tai ◽  
Hongwei Yu ◽  
Albert J. Shih
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Medical Devices ◽  
Room Temperature ◽  
Needle Insertion ◽  
Mineral Oil ◽  
Medical Procedures ◽  
Insertion Force ◽  
Needle Insertion Force ◽  
Porcine Tissues

Silicone-based tissue-mimicking phantom is widely used as a surrogate of tissue for clinical simulators, allowing clinicians to practice medical procedures and researchers to study the performance of medical devices. This study investigates using the mineral oil in room-temperature vulcanizing silicone to create the desired mechanical properties and needle insertion characteristics of a tissue-mimicking phantom. Silicone samples mixed with 0, 20, 30, and 40 wt. % mineral oil were fabricated for indentation and needle insertion tests and compared to four types of porcine tissues (liver, muscle with the fiber perpendicular or parallel to the needle, and fat). The results demonstrated that the elastic modulus and needle insertion force of the phantom both decrease with an increasing concentration of mineral oil. Use of the mineral oil in silicone could effectively tailor the elastic modulus and needle insertion force to mimic the soft tissue. The silicone mixed with 40 wt. % mineral oil was found to be the best tissue-mimicking phantom and can be utilized for needle-based medical procedures.

Needle Insertion Force Model for Haptic Simulation

2015 ◽  
Author(s):  
Adam Gordon ◽  
Inki Kim ◽  
Andrew C. Barnett ◽  
Jason Z. Moore
Keyword(s):  
Force Feedback ◽  
Needle Insertion ◽  
Model Parameters ◽  
Force Model ◽  
Medical Procedures ◽  
Insertion Force ◽  
Clinical Scenarios ◽  
Needle Insertion Force ◽  
Haptic Simulation ◽  
Simulation Systems

Percutaneous medical procedures rely upon clinicians performing precise needle insertion in soft tissue. The utility of haptic simulation systems in training clinicians for these procedures is highly dependent upon the ability to render accurate insertion force feedback. This paper presents a piecewise mathematical model for insertion force that does not require tissue material properties, detailed mechanical approximations, or complex computations. With manipulation of model parameters, a wide variety of insertion tasks and clinical scenarios can be modeled. Through needle insertion experiments and parameter estimation, this model was demonstrated to replicate the insertion forces associated with a variety of needle and tissue types. In 11 of 12 needle and tissue combinations tested, the model replicated the insertion force with an average absolute mean error of less than 0.065 N.

MECHANICS-BASED BEVEL-TIP NEEDLE DEFLECTION MODEL DURING NEEDLE–SOFT TISSUE INTERACTION PROCESS

2014 ◽  
Vol 14 (05) ◽  
pp. 1450076 ◽  
Author(s):  
SHAN JIANG ◽  
XINGJI WANG ◽  
ZHILIANG SU
Keyword(s):  
Interaction Model ◽  
Needle Insertion ◽  
Force Model ◽  
Insertion Force ◽  
Simulation Accuracy ◽  
Tissue Properties ◽  
Tissue Interaction ◽  
Needle Deflection ◽  
Tissue Equivalent ◽  
Needle Insertion Force

Flexible needle insertion is performed in many clinical and brachytherapy procedures. Needle bending which results from needle–tissue interaction and needle flexibility plays a pivotal role in implantation accuracy. In this paper, a needle insertion force model and a mechanics-based needle deflection model are applied in simulating the real needle insertion process. Using tissue-equivalent materials, the needle force model is acquired from needle insertion experiments. Based on the principle of minimum potential energy, a mechanics-based model is developed to calculate needle deflection. The needle deflection model incorporates needle insertion forces model, needle–tissue interaction model, needle geometric, and tissue properties. The bending–stretching coupling and geometric non-linearity of the flexible needle are both taken into consideration in the needle deflection model. A modified p–y curves method is first introduced in depicting the lateral needle–tissue interaction. The comparison between experimental and simulation results of needle deflection shows that our mechanics-based model can simulate the deflection of the flexible needle with reasonable accuracy. Parametric studies on different geometry properties of needles show that our mechanics-based model can precisely predict the needle deflection when more than one parameter is changed. In addition, as the needle deflection results are obtained numerically by Rayleigh–Ritz approach, further study on the form of deflection formulation leads to the conclusion that choosing a higher order polynomial can improve the overall simulation accuracy.

scholarly journals Modeling of geometry and insertion force of a new lancet medical needle

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041989107
Author(s):  
Yingchun Qi ◽  
Jingfu Jin ◽  
Tingkun Chen ◽  
Qian Cong
Keyword(s):  
Great Influence ◽  
Large Change ◽  
Processing Parameters ◽  
Needle Insertion ◽  
Grinding Wheel ◽  
Insertion Force ◽  
Factors Affecting ◽  
Organ Tissue ◽  
Needle Insertion Force ◽  
The Relationship

Lancet needle is a typical medical treatment device. Its tip consists of two lancet planes and one bevel plane. When the lancet needle is inserted into soft organ tissue, the insertion force may influence the needle cutting direction and treatment effect and increase the pain. One of the main factors affecting this insertion force is the geometry of the needle tip. Based on the research on the shape and processing method of the conventional lancet needle, a new lancet needle tip geometry was obtained by adjusting the relative position of the grinding wheel to the needle. A mathematical model of this new lancet needle was established. The relationship between processing parameters and needle shape was analyzed, and the needle insertion force was predicted. Compared with the conventional lancet needle, the new lancet needle is sharper, and the insertion force on the cutting edge is smaller. However, this change in the grinding position of the needle lancet plane has a great influence on the shape of needle tip near the intersection of the bevel plane and the lancet plane. Some special second bevel angle and rotated angle will cause a large change in the specific force at the intersection place, which is not conducive to reducing the insertion force.

Effects of Helium Implantation on the Mechanical Properties of 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 721-724 ◽  
Author(s):  
Jean François Barbot ◽  
Marie France Beaufort ◽  
Valerie Audurier
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Room Temperature ◽  
Critical Level ◽  
High Fluence ◽  
Vacancy Defects ◽  
Helium Implantation ◽  
Low Levels

The evolution of mechanical properties of helium-implanted 4H-SiC at room temperature has been mainly studied by nanoindentation tests. The curves of hardness and elastic modulus present a maximum at low levels of damage while a degradation of the mechanical properties is observed for high levels of damage. However, when the concentration of implanted ions exceeds 0.5 %, complex defects (helium-vacancy defects) become predominant which results in the increase of both the hardness and the modulus. Under high fluence of helium implantation tiny bubbles form and the amorphous transition is observed above a critical level of damage.

Charge storage and mechanical properties of porous PTFE and composite PTFE/COC electrets

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Wen-Ching Ko ◽  
Chien-Kai Tseng ◽  
Wen-Jong Wu ◽  
Chih-Kung Lee
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Elastic Modulus ◽  
Surface Potential ◽  
Room Temperature ◽  
Base Material ◽  
Processing Method ◽  
Charge Storage ◽  
Ptfe Film ◽  
Potential Decay

AbstractRecent futuristic applications of flexible electret loudspeakers have garnered much interest for these novel loudspeakers. To increase the loudspeaker properties, a processing method was developed to improve the electret and mechanical properties of porous PTFE film. Taking a thin porous PTFE film as the base material, a cyclic olefin copolymer (COC) was coated to a base material to form a PTFE/COC composite film. Results show that the composite material improves the advantageous characteristics when used as an electret diaphragm for loudspeakers. By measuring the surface potential decay and the elastic modulus, properties of a standard porous PTFE film were compared to an improved composite PTFE/COC film. Experimental results showed that the composite PTFE/COC possess the following advantages: (1) 80% higher surface potential after 10 days at room temperature, (2) a better thermal resistance of charge storage, and (3) a 643% higher elastic modulus. Therefore, our novel composite material can be used to create a much improved electret diaphragm for flexible electret loudspeakers.

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