A novel testing system for biomechanical evaluation of the bone or bone fixator

Sensor Review ◽  
2018 ◽  
Vol 38 (4) ◽  
pp. 405-411
Author(s):  
Zhanshe Guo ◽  
Zhaojun Guo ◽  
Xiangdang Liang ◽  
Shen Liu
Keyword(s):  
Good Condition ◽  
Force Sensor ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Sensor Calibration ◽  
Testing System ◽  
Static Force ◽  
Content Type ◽  
New Device ◽  
Bending Force

Purpose Biomechanical properties of bones and fixators are important. The aim of this study was to develop a new device to simulate the real mechanical environment and to evaluate biomechanical properties of the bone with a fixation device, including the static force and the fatigue characters. Design/methodology/approach In this paper, the device is mainly composed of three parts: pull-pressure transmission system, bending force applying system and torsion applying system, which can successfully simulate the pre-introduced pull-pressure force, bending force and torsion force, respectively. To prove the feasibility of the design, theoretical analysis is used. It is concluded from the simulated result that this scheme of design can successfully satisfy the request of the evaluation. Findings Finally, on the basis of the force sensor calibration, the static force experiment and fatigue experiment are carried out using the tibia of the sheep as the specimen. It is concluded from the result that the relationship between the micro displacement and the applied axial force is nearly linear. Under the condition of 1 Hz in frequency, 500 N in loading force and 18,000 reciprocating cycles, the bone fixator can still be in good condition, which proves the feasibility of the design. Originality/value Biomechanical properties of bones and fixators are studied by researchers. However, few simulate a real force environment and combine forces in different directions. So a novel system is designed and fabricated to evaluate the biomechanical properties of the bones and fixators. Results of the experiments show that this new system is reliable and stable, which can support the biomechanical study and clinical treatment.

Biomechanical properties of expander compared with conventional screws

2002 ◽  
Vol 97 (3) ◽  
pp. 346-349 ◽  
Author(s):  
Aziz Rassi-Neto ◽  
Antonio Shimano
Keyword(s):  
Maximum Load ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Intergroup Difference ◽  
Content Type ◽  
Significant Difference ◽  
Group 2 ◽  
The Comparative Study ◽  
Screw Group ◽  
Fine Print

Object. A pullout strength biomechanical study was performed in 20 fresh swine vertebral bodies in which titanium expander (Group 1) and conventional screws (Group 2) were placed. Methods. The screws were inserted into the anterosuperior portion of the anterior spine, and assessment was performed after application of loads. The expander screw is composed of two parts: 1) a cover with an external portion comprising tight thin threads; and 2) a compact internal screw inserted through the cover that allows expansion. In the comparative study between the screws in Groups 1 and 2 maximum load was assessed, and the intergroup difference was significant (p = 0.00001 [t-test]); regarding load at the elasticity threshold, a significant difference was also observed (p = 0.0063). With regard to rigidity (stiffness), there was a tendency in both groups toward significance (p = 0.069). With regard to absorbed energy in the elastic phase, statistical analysis showed a significant intergroup difference (p = 0.00439). The expander screw showed a greater load-bearing capacity than the conventional screw. Adhesion to bone in relation to the applied load and displacement was greater (significant tendency) in the expander screw group than in the conventional screw group. Conclusions. The expander screws exhibited a greater capacity to absorb energy in the elastic phase. They adhered better to bone, were easy to insert, and, if necessary, were simple to remove.

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

A COMPARATIVE BIOMECHANICAL STUDY OF THE LOOPED SQUARE SLIP KNOT AND THE SIMPLE SURGICAL KNOT

Hand Surgery ◽  
2006 ◽  
Vol 11 (01n02) ◽  
pp. 93-99 ◽  
Author(s):  
Surut Jianmongkol ◽  
Geoffrey Hooper ◽  
Weerachai Kowsuwon ◽  
Tala Thammaroj
Keyword(s):  
Ultimate Strength ◽  
Hand Surgery ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Skin Closure ◽  
Significant Difference ◽  
Mode Of Failure ◽  
Repetitive Loading ◽  
Slip Knot

The looped square slip knot was introduced as a technique for skin closure to avoid the use of sharp instruments in suture removal after hand surgery. We compared the biomechanical properties of this knot with the simple surgical square knot. The ultimate strength of the looped square slip knot was significantly (p = 0.015) higher than the simple surgical knot. There was no significant difference between the two knots in mode of failure. Knot slippage or suture breakage did not occur in any samples when testing security by repetitive loading. Therefore, the looped square slip knot is a safe and convenient alternative to the two-throw surgical knot for use in hand surgery.

scholarly journals Static Force Measurement Using Piezoelectric Sensors

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Kyungrim Kim ◽  
Jinwook Kim ◽  
Xiaoning Jiang ◽  
Taeyang Kim
Keyword(s):  
Surface Charge ◽  
Piezoelectric Effect ◽  
Force Measurement ◽  
Piezoelectric Materials ◽  
Force Sensor ◽  
Piezoelectric Sensors ◽  
Force Sensing ◽  
Static Force ◽  
Sensing Applications ◽  
Direct Piezoelectric Effect

In force measurement applications, a piezoelectric force sensor is one of the most popular sensors due to its advantages of low cost, linear response, and high sensitivity. Piezoelectric sensors effectively convert dynamic forces to electrical signals by the direct piezoelectric effect, but their use has been limited in measuring static forces due to the easily neutralized surface charge. To overcome this shortcoming, several static (either pure static or quasistatic) force sensing techniques using piezoelectric materials have been developed utilizing several unique parameters rather than just the surface charge produced by an applied force. The parameters for static force measurement include the resonance frequency, electrical impedance, decay time constant, and capacitance. In this review, we discuss the detailed mechanism of these piezoelectric-type, static force sensing methods that use more than the direct piezoelectric effect. We also highlight the challenges and potentials of each method for static force sensing applications.

scholarly journals Differential Spleen Remodeling Associated with Different Levels of Parasite Virulence Controls Disease Outcome in Malaria Parasite Infections

mSphere ◽  
2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Ximei Huang ◽  
Sha Huang ◽  
Lai Chun Ong ◽  
Jason Chu-Shern Lim ◽  
Rebecca Joan Mary Hurst ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Malaria Parasite ◽  
Parasite Clearance ◽  
Biomechanical Properties ◽  
Parasite Infection ◽  
Complex Interaction ◽  
Content Type ◽  
Key Factor ◽  
Infected Rbcs ◽  
Rbc Deformability

ABSTRACT The spleen and its response to parasite infection are important in eliminating parasites in malaria. By comparing P. yoelii parasite lines with different disease outcomes in mice that had either intact spleens or had had their spleens removed, we showed that upon parasite infection, the spleen exhibits dramatic changes that can affect parasite clearance. The spleen itself directly impacts RBC deformability independently of parasite genetics. The data indicated that the changes in the biomechanical properties of malaria parasite-infected RBCs are the result of the complex interaction between host and parasite, and RBC deformability itself can serve as a novel predictor of clinical outcome. The results also suggest that early responses in the spleen are a key factor directing the clinical outcome of an infection. Infections by malaria parasites can lead to very different clinical outcomes, ranging from mild symptoms to death. Differences in the ability of the spleen to deal with the infected red blood cells (iRBCs) are linked to differences in virulence. Using virulent and avirulent strains of the rodent malaria parasite Plasmodium yoelii, we investigated how parasite virulence modulates overall spleen function. Following parasite invasion, a difference in parasite virulence was observed in association with different levels of spleen morphology and iRBC rigidity, both of which contributed to enhanced parasite clearance. Moreover, iRBC rigidity as modulated by the spleen was demonstrated to correlate with disease outcome and thus can be used as a robust indicator of virulence. The data indicate that alterations in the biomechanical properties of iRBCs are the result of the complex interaction between host and parasite. Furthermore, we confirmed that early spleen responses are a key factor in directing the clinical outcome of an infection. IMPORTANCE The spleen and its response to parasite infection are important in eliminating parasites in malaria. By comparing P. yoelii parasite lines with different disease outcomes in mice that had either intact spleens or had had their spleens removed, we showed that upon parasite infection, the spleen exhibits dramatic changes that can affect parasite clearance. The spleen itself directly impacts RBC deformability independently of parasite genetics. The data indicated that the changes in the biomechanical properties of malaria parasite-infected RBCs are the result of the complex interaction between host and parasite, and RBC deformability itself can serve as a novel predictor of clinical outcome. The results also suggest that early responses in the spleen are a key factor directing the clinical outcome of an infection.

Vision-force guided precise robotic assembly for 2.5D components in a semistructured environment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Boyoung Kim ◽  
Minyong Choi ◽  
Seung-Woo Son ◽  
Deokwon Yun ◽  
Sukjune Yoon
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Printed Circuit Board ◽  
Force Sensor ◽  
Circuit Board ◽  
Robotic Assembly ◽  
Ccd Cameras ◽  
Content Type ◽  
3 Dimensional ◽  
Aided Design

Purpose Many manufacturing sites require precision assembly. Particularly, similar to cell phones, assembly at the sub-mm scale is not easy, even for humans. In addition, the system should assemble each part with adequate force and avoid breaking the circuits with excessive force. The purpose of this study is to assemble high precision components with relatively reasonable vision devices compared to previous studies. Design/methodology/approach This paper presents a vision-force guided precise assembly system using a force sensor and two charge coupled device (CCD) cameras without an expensive 3-dimensional (3D) sensor or computer-aided design model. The system accurately estimates 6 degrees-of-freedom (DOF) poses from a 2D image in real time and assembles parts with the proper force. Findings In this experiment, three connectors are assembled on a printed circuit board. This system obtains high accuracy under 1 mm and 1 degree error, which shows that this system is effective. Originality/value This is a new method for sub-mm assembly using only two CCD cameras and one force sensor.

scholarly journals A Novel Fixation System for Acetabular Quadrilateral Plate Fracture: A Comparative Biomechanical Study

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Guo-Chun Zha ◽  
Jun-Ying Sun ◽  
Sheng-Jie Dong ◽  
Wen Zhang ◽  
Zong-Ping Luo
Keyword(s):  
Plate Fixation ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Pelvic Brim ◽  
Quadrilateral Plate ◽  
Plate Fracture ◽  
Fixation Techniques ◽  
Biomechanical Experiment ◽  
Fixation System

This study aims to assess the biomechanical properties of a novel fixation system (named AFRIF) and to compare it with other five different fixation techniques for quadrilateral plate fractures. This in vitro biomechanical experiment has shown that the multidirectional titanium fixation (MTF) and pelvic brim long screws fixation (PBSF) provided the strongest fixation for quadrilateral plate fracture; the better biomechanical performance of the AFRIF compared with the T-shaped plate fixation (TPF), L-shaped plate fixation (LPF), and H-shaped plate fixation (HPF); AFRIF gives reasonable stability of treatment for quadrilateral plate fracture and may offer a better solution for comminuted quadrilateral plate fractures or free floating medial wall fracture and be reliable in preventing protrusion of femoral head.

Design and characterization of a T-shaped two-axis force sensor

Sensor Review ◽  
2019 ◽  
Vol 39 (6) ◽  
pp. 776-782
Author(s):  
Liang Zhong ◽  
Feifei Li ◽  
Yuxin Peng ◽  
Qiang Yang ◽  
Mingming Zhang ◽  
...  
Keyword(s):  
Design Methodology ◽  
Simple Structure ◽  
Force Sensor ◽  
The Other ◽  
Strain Gauges ◽  
Content Type ◽  
Sensor Head ◽  
Compact Size ◽  
Basic Performance

Purpose This paper aims to propose a type of T-shaped two-axis force sensor for measuring the forces in x- and z-axes. The developed sensor has a simple structure and can be effectively assembled into compact devices. Design/methodology/approach A T-shaped plate, with both ends fixed on a base, is used as the substrate of the sensor. Eight strain gauges are placed in the root of the plate or near the sensor head, which can construct two full Wheatstone bridges on the upper and lower surfaces of the plate. When the x- or z-axes forces are applied to the sensor head, different deformation can be generated to the strain gauges. Therefore, the two Wheatstone bridges can be constructed with a different configuration for measuring the forces in x- or z-axes, respectively. Findings A prototype was designed and constructed and experiments were carried out to test the basic performance of the sensor. It has been verified that the developed sensor could measure the x- and z-axes forces independently with a high resolution of 2.5 and 5 mN, respectively. Originality/value Only one thin plate was used in the design, the forces in x- and z-axes could be measured independently and simultaneously, which made the sensor with a simple structure and compact size. Experiments were also verified that there was no crosstalk error occurred in one axis when the force was applied to the other axis.

Optimization of internal thread structure of force sensor considering fatigue performance

Sensor Review ◽  
2019 ◽  
Vol 39 (6) ◽  
pp. 835-843
Author(s):  
Hongchun Sun ◽  
Tianlu Wang ◽  
Xindong Zhang
Keyword(s):  
Fatigue Life ◽  
Force Sensor ◽  
Fatigue Performance ◽  
Internal Thread ◽  
Outer Diameter ◽  
Optimized Design ◽  
Content Type ◽  
Performance Requirements ◽  
Design Requirements ◽  
Thread Structure

Purpose Fatigue damage of internal threads has gradually become the main failure mode of force sensor. To make the internal thread structure of force sensor meet the fatigue performance requirements, the design criteria of static strength and fatigue life are comprehensively considered in this paper. Design/methodology/approach The variation of static stress and fatigue life with the size of the main structure is obtained by simulation. By changing the number of thread turns, the hub height and outer diameter of the hub, the optimized design of the spoke force sensor is determined. Findings The experiment was carried out based on the determined optimized structure, and the results showed that the fatigue life meets the design requirements. Originality/value This research has certain guiding significance for the design and developments of high-cycle fatigue force sensors.

A new method to access information for underground omni-dimensional vibration vector

Sensor Review ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Jian Li ◽  
Ying Liu ◽  
Yan Han ◽  
Xianhui Chen
Keyword(s):  
Vibration Signal ◽  
Vibration Sensor ◽  
New Method ◽  
Underground Explosion ◽  
Sensor Calibration ◽  
Signal Acquisition ◽  
Element Analysis ◽  
Content Type ◽  
Sensor Structure ◽  
Vector Signal

Purpose – The purpose of this paper is to propose a new method to achieve omni-directional vibration vector signal acquisition, and use this method to improve the accuracy of the underground explosion point localization. Design/methodology/approach – Following an introduction, this paper describes the design principle of a sensor structure, and discusses the rationality of the spherical structure of the sensor through finite element analysis. The sensor prototype is designed according to the above method, and its performance is tested by the sensor calibration experiment. Finally, applications are also discussed. Findings – This paper shows that the method for underground omni-directional vibration signal acquisition is reasonable and feasible. The vibration sensor, designed by this method, of which the triaxial dynamic characteristics are consistent, and the three-dimensional vibration information acquired by this sensor can achieve high-precision localization for an underground explosion point. Originality/value – The paper describes a new method for omni-directional vibration vector signal acquisition. The vibration sensor is developed based on this method, which has a broad application prospect in the positioning of an underground explosion point, the evaluation of explosive power and other underground projects.

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