Rubber Tube Research Articles

Automated Disease Detection in Gastroscopy Videos Using Convolutional Neural Networks.

A large percentage of the world's population is affected by gastric diseases ranging from erosion and ulcer to serious ailments such as gastric cancer, which is mainly caused by Helicobacter pylori(H.pylori) infection. While most erosions and ulcers are benign, severe cases of gastric diseases can still develop into cancer. Thus, early screening and treatment of all gastric diseases are of great importance. Upper gastroscopy is one such common screening procedure that visualizes the patient's upper digestive system by inserting a camera attached to a rubber tube down the patient's digestive tracts, but since the procedure requires manual inspection of the video feed, it is prone to human errors. To improve the sensitivity and specificity of gastroscopies, we applied deep learning methods to develop an automated gastric disease detection system that detects frames of the video feed showing signs of gastric diseases. To this end, we collected data from images in anonymous patient case reports and gastroscopy videos to train and evaluate a convolutional neural network (CNN), and we used sliding window to improve the stability of our model's video performance. Our CNN model achieved 84.92% sensitivity, 88.26% specificity, and 85.2% F1-score on the test set, as well as 97% true positive rate and 16.2% false positive rate on a separate video test set.

Transient Chemical Activation of Covalent Bonds for Healing of Kinetically Stable and Multifunctional Organohydrogels

Transient Chemical Activation of Covalent Bonds for Healing of Kinetically Stable and Multifunctional Organohydrogels

Highly Articulated Tube Mechanism With Variable Stiffness and Shape Restoration Using a Pneumatic Actuator

Recently, soft robotics research has focused on mechanisms to control the stiffness of robot structures. There are several types of variable stiffness mechanisms that can change the stiffness of such structures by altering friction force. Among these, the negative-pressurization method applies negative pressure to the particles or layers that are filled inside a bag so that they contact each other and increase stiffness. However, the maximum driving pressure that can be achieved using the negative-pressurization method is 0.1 MPa, which limits the stiffness. In this study, we devised a new fluid-driven mechanism that can change the stiffness through positive pressurization using pneumatic artificial muscles. The proposed structure constructed with hollow beads and inner muscles can hold arbitrary joint angles by the contraction force generated when a pressure is applied. We measured the torque in the pitch direction due to friction when the internal pressure and inner segment diameter were changed. We confirmed that the error between the measured and theoretical torque value was within a 20% at any inner diameter. Also, since a pneumatic artificial muscle is enclosed inside the structure, an actuation effect can occur when the pressure is applied. We measured the restoring angle and force of this effect when the valve opening ratio and inner segment diameter were changed. We confirmed the function that can change the shape restoration characteristics by changing the flow rate with a single rubber tube. Our approach will help design effective stiffening mechanisms using positive pressurization in soft robotics applications. In future, we will design a tensioner mechanism for arbitrarily changing the distance of segments in the axial direction, and we will investigate the holding torque, restoring angle and force when the distance of the segments is changed.

Human Movement Monitoring Simulation Using an IoT-based self-powered TENG Intelligent Chair

Abstract: The internet has had a profound effect on human life. Since each individual has distinct movement characteristics, monitoring human motion can enable identity recognition. This paper describes the development of a self-powered triboelectric nanogenerator (TENG) band's array for recognizing students' identities in the classroom by collecting movement information derived from electric signals during sitting, standing, turning left and right while sitting, and breathing on the chair. The band's array is soft, stretchy, and cheap, constructed of a rubber tube filled with locally created physiological saline. It can be mounted on the intelligent chair in two positions: seat and backrest. Furthermore, utilizing MATLAB software and a specialized algorithm, the band's array can identify and authenticate students' identification in real-time with an ERR of 19.6 %. Keywords: Intelligent chair; self-powered Triboelectric Nanogenerator; Internet of Things; student motion detection; Identity recognition

An Innovative and Economical Device for Ischemic Preconditioning of the Forehead Flap Prior to Pedicle Division: A Comparative Study.

Ischemic preconditioning of the forehead flap prior to pedicle division helps to improve angiogenesis. Clamping the pedicle by a clamped rubber band with vessel forceps is often clinically applied. However, the severe pain and unstable blocking effect influenced the preconditioning process. In this study, we described an innovative device designed for ischemic preconditioning and compared its efficacy with the clamped rubber band. The device consists of a self-locking nylon cable tie with a buckle and a rubber tube. The rubber tube is fed over the cable tie to act as a soft outer lining and the cable tie is tightened across the pedicle to block the perfusion for ischemic preconditioning. This device and the standard clamped rubber band were applied respectively before division surgery. The constriction effect, reliability, reproducibility, and the patients' pain tolerance were compared. A total of 20 forehead flaps were included. The cable tie had less incidence of loosening (7.7% vs. 16.6%, p < 0.05) and maintained the pressure more effectively. The pain score for the nylon cable tie was significantly lower than the clamped rubber band (4.25 ± 1.02 vs. 6.75 ± 1.12, p < 0.05), especially for 10 pediatric patients (4.50 ± 0.85 vs. 8.10 ± 1.20, p < 0.01). All 20 pedicles were successfully divided at 19 to 22 days with no surgical complications. Compared with the clamped rubber band, the cable tie produces a more reliable and reproducible ischemic preconditioning effect. It is also better tolerated by the patients. Therefore, we recommend using the nylon cable tie as the preferred device for ischemic preconditioning of the forehead flap.

A Low-Cost Non-Invasive Continuous Cardiovascular Monitoring System Based on Oil-Filled Rubber Tubing

Cardiovascular monitoring at home is highly desirable for managing diseases such as heart failure. Existing technologies are either inconvenient, too costly, or incapable of acquiring clinically valuable information. We developed a new low-cost and sensitive monitoring system based on rubber tubing, mineral oil, and an off-the-shelf pressure sensor. The rubber tube can be installed underneath bed mattresses and chair cushions to convert the ballistocardiogram (BCG) signal caused by heartbeat to pressure change, which is then detected by the pressure sensor. The sensitivity is increased by filling the tube with mineral oil based on Boyle&#x2019;s gas law (PV &#x003D; Constant). Preliminary tests demonstrated that the new monitoring system can record BCG with high sensitivity from the bed. From the recorded signal, both heart rate and respiration rate can be extracted. Other valuable information such as myocardial strength and respiration strength can be potentially derived as well. The new monitoring system is low-cost, sensitive, robust, unattended, and does not need to attach any device to the patient. This new monitoring system will be beneficial for the monitoring of health conditions such as heart failure, sleep apnea, epilepsy, and respiratory diseases such as COVID-19.

Catching Speedy Gonzales: Driving forces for Protein Film Formation on Silicone Rubber Tubing During Pumping

Interfacial adsorption is a major concern in the processing of biopharmaceutics as it not only leads to a loss of protein, but also to particle formation. Protein particle formation during peristaltic pumping is linked to interfacial adsorption to the tubing and subsequent tearing of the formed protein film. In the current study, driving forces and rate of the adsorption of a monoclonal antibody to the silicone rubber surface during pumping, as well as particle formation, were studied in different formulations. Particle concentration and size distribution were influenced by the formulation parameters; specifically high ionic strength led to more particles and the build-up of particles larger than 25 µm. Formulation pH and ionic strength had an effect on the total amount of adsorbed protein. Adsorbed protein amounts increased when the Debye length of the protein was decreased, leading to a higher packing density. Atomic force microscopy and streaming potential determination revealed that the irreversible protein film formation on the hydrophobic tubing surface occurs in less than a second. Electrostatic interactions are the dominating factor for the initial adsorption speed. In intimate contact to the silicone rubber surface, hydrophobic interactions govern the protein adsorption. PS20 quickly coats the tubing surface which leads to an increase in hydrophilicity and shielding of electrostatic interactions, thereby efficiently inhibiting protein adsorption. Overall, atomic force microscopy and streaming potential determination possess great potential for the characterization of adsorbed protein films and the adsorption kinetic evaluation in high-speed mode. Protein adsorption to silicone tubing is driven by a combination of electrostatic and hydrophobic interactions which is effectively shielded by PS20.

A study on multi-axis dynamic absorber with frequency tuning function using pneumatic rubber tube springs

A multi-axial dynamic vibration absorber (DVA) with adjustable natural frequency mechanism has been developed. Air-filled rubber tubes are used as the spring and damping elements of the DVA, which support each face of the iron cubic auxiliary mass. For the rubber tube, when the internal air pressure is increased, the support stiffness is increased by expansion and pressing between the acrylic plate (which constitutes the outer frame of the DVA) and the auxiliary mass. In this way, the natural frequencies of the DVA can be adjusted by manipulating the air pressure. As a first step to realize a multi-axis DVA with frequency tuning ability, this study reports the vibration characteristics of the developed DVA when the air pressure of the supporting rubber tubes is changed uniformly.

Braid Angle and its Influence on the Hydraulic Hoses Behaviour Under Pressure Loading

This paper deals with the experimental analysis of the effect of the braid angle on the behaviour of a hydraulic hose under pressure loading. The main structural elements of the hose are a rubber tube and a steel braid or spiral. The material of the braid and the number of braids influence the magnitude of the pressure load on the hydraulic hose. The angle of the braid affects the deformation of the hydraulic hose when the inner wall is loaded with fluid pressure. For hydraulic hoses, it is a requirement to maintain a neutral braid angle during manufacture to ensure a balance between axial and circumferential stresses under pressure loading. An experimental device was set up to measure the hoses. This device can be used to measure the diameter of the outer braid, the length and the tensile force of the hose in the axial direction and, where appropriate, to evaluate the angle of the outer braid of the hose as a function of the fluid pressure loading on the inner wall of the hose. The object of the research is to determine the effect of the braid angle on the behaviour of the hydraulic hose under pressure loading. Based on the measurements, the dependencies of the tensile force, the braid angle and the change in length of hydraulic hoses on the internal pressure were determined. In order to compare the measurement results, hydraulic hoses with different inner diameters and different numbers of braids or spirals were selected. Research background: Description of neutral braid angle, hydraulic hose geometry, tensile force of hose. Purpose of the article: Influence of braid angle on the hydraulic hoses behaviour under pressure loading. Methods: Experimental measurements. Findings &amp; Value added: Determining of the change of length dependencies on the pressure, determining of the tensile force dependencies on the pressure.

Rhinoscleroma – still a predominant entity managed by rubber tube recanalization

Rhinoscleroma is a chronic granulomatous infection affecting the nasal cavity and nasopharynx primarily. It results in functional and esthetic sequelae in patients. A patient presented to us with chronic extensive vestibular stenosis with external deformity of the nose. The patient underwent multistaged diagnostic nasal endoscopy with biopsy and recanalization using a sterile rubber catheter which showed significant clinical improvement. This case demonstrates that medical advancements have enabled a quicker diagnosis of rhinoscleroma and recanalization still remains an essential entity in managing the sequelae of rhinoscleroma.

Migration, Mobility and the Making of a Global Europe

In 2017–18, the Chinese artist Ai Weiwei created a special installation addressing the refugee crisis in Prague. ‘Law of the Journey’ consisted of an enormous black inflatable raft, crowded with inflatable rubber people wearing lifejackets. Their human forms were clear, but they lacked faces. The raft hung from the ceiling at an angle, casting a dark shadow over a list of quotations from thinkers and writers, beginning and ending with two locals: Franz Kafka and Václav Havel. A few isolated rubber tubes floated on the concrete floor next to the raft, with rubber humans reaching out to be saved. The exhibit conveyed both the desperation of the migrants and the inadequacy of the response.

Axial compressive behavior of rubberized concrete-filled steel tube short columns

With different volume replacement ratios of rubber fine aggregate and thicknesses of steel tube, 12 rubberized concrete-filled steel tube (RuCFST) columns were fabricated. Then axial compressive tests were completed. The test results show that RuCFST columns exhibit lower axial compressive capacity and higher ductility than normal CFST columns. The steel tube of the RuCFST with a high rubber replacement ratio is more prone to local buckling and the axial load-displacement curves of RuCFST columns tends to exhibit hardening post-peak response. Based on the experimental results, the relationship between the critical value of the confinement coefficient and the rubber replacement ratio of RuCFST columns was obtained. Then, the axial compressive strength of RuCFST columns was investigated by Eurocode4, AISC360-16 and GB 50936-2014 codes. The results show that the predictions by those codes are conservative. Finally, by considering the higher ductility of RuCFST columns and full use of material properties, a modified formula to calculate the compressive strength of RuCFST columns was proposed and then validated by the experimental results.

Development of a volumetric compression restrainer for structures subjected to vibration

In the last 2 decades, application of viscous dampers as restrainer device (lock-up) in buildings and bridges to diminish harmful effect of vibrations. However, leakage issue in the viscous luck-up devices requires regular expensive maintenance procedure to prevent device performance failure and many researchers are encouraged to find an alternative system with low maintenance cost. Therefore, in this study the Volumetric Compression Restrainer (VCR) device has been developed as a new effective restrainer system using hyper-elastic rubber material. The VCR device is consisted of multi hyperelastic rubber tubes which positioned within steel cylinder with core and applicable in the structures as vibration resistance system. To develop VCR device, the primary design details are derived and the behavior of proposed VCR subjected to various dynamic load conditions has been assessed through the finite element simulation. In order to define the hyper-elastic characteristics of the rubber material for finite element modeling, the hyperelastic rubber material with 3 different hardness properties have been tested experimentally. Then in the next step, the rubber test data were used to develop the analytical model for the VCR device. So, the performance of the VCR device was determined by applying cyclic load to the developed FEM model. Afterwards, multiple prototypes of VCR devices have been manufactured with four different rubber hardness properties and two different configurations and a series of experimental tests have been conducted to validate the device performance.Then, a three-story concrete frame equipped with supplementary VCR device subjected to seismic loads is considered and the performance of VCR and its efficiency to diminish vibration effect are evaluated. Besides, the hybrid population-based algorithm (PSOGSA) is implemented to optimize design of structure equipped with VCR device under applied earthquake excitation. The results revealed that by implementing VCR device as supplementary restrainer system in the frame structure, lateral displacement is reduced in range of 31.5–61.2% compared to the bare structures which is proving the efficiency of developed VCR device to protect the structures against severer dynamic loads.

A Wearable Soft Fabric Sleeve for Upper Limb Augmentation.

Soft actuators (SAs) have been used in many compliant robotic structure and wearable devices, due to their safe interaction with the wearers. Despite advances, the capability of current SAs is limited by scalability, high hysteresis, and slow responses. In this paper, a new class of soft, scalable, and high-aspect ratio fiber-reinforced hydraulic SAs is introduced. The new SA uses a simple fabrication process of insertion where a hollow elastic rubber tube is directly inserted into a constrained hollow coil, eliminating the need for the manual wrapping of an inextensible fiber around a long elastic structure. To provide high adaptation to the user skin for wearable applications, the new SAs are integrated into flexible fabrics to form a wearable fabric sleeve. To monitor the SA elongation, a soft liquid metal-based fabric piezoresistive sensor is also developed. To capture the nonlinear hysteresis of the SA, a novel asymmetric hysteresis model which only requires five model parameters in its structure is developed and experimentally validated. The new SAs-driven wearable robotic sleeve is scalable, highly flexible, and lightweight. It can also produce a large amount of force of around 23 N per muscle at around 30% elongation, to provide useful assistance to the human upper limbs. Experimental results show that the soft fabric sleeve can augment a user’s performance when working against a load, evidenced by a significant reduction on the muscular effort, as monitored by electromyogram (EMG) signals. The performance of the developed SAs, soft fabric sleeve, soft liquid metal fabric sensor, and nonlinear hysteresis model reveal that they can effectively modulate the level of assistance for the wearer. The new technologies obtained from this work can be potentially implemented in emerging assistive applications, such as rehabilitation, defense, and industry.

Learning Pattern of Two-Dimensional, Three-Dimensional, and Ultra-High-Definition Endovision System on Standardized Phantom Tasks: An Ex Vivo Randomized Study.

Introduction: Three-dimensional (3D), high-definition (HD), and ultra-high-definition (4K HD) are recent additions over regular HD technology for laparoscopic surgery. The aim of this study was to evaluate the learning pattern of these systems on standardized phantom tasks. Methodology: Forty-five stereo-enabled resident doctors were randomly assigned into three groups. They performed three validated tasks, precision touch on flat surface, precision touch on uneven surface, surgical knot on rubber tube using either two-dimensional (2D) HD, 3D HD, or 4K HD Endovision systems. Each task was repeated 20 times. Data from four consecutive repetitions were pooled to make five blocks. Split group analysis by comparing the consecutive blocks in execution time and errors were made to see the learning pattern. A significant difference was accepted as continuous learning while no significant difference was accepted as learning stabilization. Result: Operating time was stabilized in two tasks after third block in 2D HD, one task after fourth block in 4K HD. There was continuous learning in all tasks with 3D HD. The 3D HD group was significantly faster than 2D HD and 4K HD in most of the tasks on fifth block. The error scores were similar between the consecutive blocks in 4K HD. It was stabilized after second block in 2D HD group and third block on 3D HD. Conclusion: The 3D HD Endovision system has more potential of faster execution of a task, but need more practice to reach similar safety profile. The 4K HD reached the safety plateau with minimal repetitions.

Developing Student-Teachers’ Understanding of Geometrical Figures/Objects Using a Bicycle Rubber Tube

This paper addresses the ways that a bicycle rubber tube can be used to develop learners’ understanding of geometrical figures/objects. The use of a bicycle rubber tube is important because student-teachers and in-service teachers can use the material to teach learners in schools to understand various geometrical figures/objects. In doing so, geometrical figures and objects, metric, and metric space are understood relationally. Using a bicycle rubber tube, it was found that various geometrical figures and objects were formed, including rectangle, triangle, square, and pentagon. The finding has implications in teaching geometrical figures/objects, including teachers can use a bicycle rubber tube to develop learners’ understanding of a circle, rectangle, triangle, square, pentagon and hexagon.

Cost Effective Simulation Model for Laparoscopic Uretero-Ureterostomy

<h3>Study Objective</h3> The objectives of this video are to review the techniques of uretero-ureterostomy, to develop a low-cost simulation model, and to provide instruction to gynecologists on how to perform this procedure in the absence of a urologist. <h3>Design</h3> A simulation model for ureteral re-anastomosis was created using rubber tubing and a pipe cleaner. The model was placed in a laparoscopic simulation box trainer, and the steps of the procedure are reviewed in sequence. <h3>Setting</h3> Simulation center at an academic tertiary care center. <h3>Patients or Participants</h3> N/A. <h3>Interventions</h3> The simulation model was developed and explained during the course of the video. <h3>Measurements and Main Results</h3> A piece of rubber tubing is placed in a laparoscopic box simulator, and both ends are secured. A cut is made in the mid-portion of the tube to mimic a ureteral injury. Spatulation is performed to both the proximal and distant parts of the ureter. A pipe cleaner is introduced into both ends of the tube in order to simulate a ureteral stent. Once the stent is secure, we check if the spatulated ends are in position. Interrupted sutures are placed to secure the ureteral ends in the correct anatomical position. Intra-corporeal knot tying is performed to secure the sutures. <h3>Conclusion</h3> Our simulated uretero-ureterostomy model can easily be reproduced to teach residents, fellows, and early career physicians how to repair a ureter laparoscopically. We feel that simulation is essential to teach surgical skills, and ureteral re-anastomosis is a highly technical skill that is very useful for gynecologists who may not always have access to Urology consultation. Using a low-cost model like ours is helpful to practice the steps of the procedure and build confidence for surgeons who may find themselves in an emergent situation where ureteral repair is required.

A new incremental calculated approach to predict maximum contact stress of compressed packer in large deformation

Compressed packer rubber is large deformation material, which endures biaxial contact friction between oil-pipe and casing-pipe in sitting and sealing process. Large-deformation theory analysis of rubber brings huge difficulties to solve, this is due to the material, geometry and contact non-linearity should be considered. In this article, the deformation of compressed packer rubber tube (CPRT) is divided into free deformation, unidirectional and bidirectional constrained deformations. Based on the theory of thick-wall-cylinder and the linear constitutive of rubber material segment, the CPRT mathematical model in different deformation processes is established and the influences of axial load, axial height of CPRT and contact friction coefficient of casing inner wall etc are considered. Based on incremental calculated approach, the mathematical model is solved. By comparing the results of the theoretical model with the results of finite element method and experimental results, it is found that the theoretical maximum contact stress is more conservative than the FEM and experimental solutions, so the sealing reliability of packer effectively predicted under the premise of allowable contact stress and the theoretical results can provide a lower limit reference value for the contact stress of the packer in the actual seal process. Meanwhile, the deviation of contact stress in FEM and theoretical value at z150 height of CPRT is among 1.13%∼4.90%, which can predict the contact stress in the compressed area near the stress concentration upper end-face of CPRT under the low friction factor, the results provide a reference for the compressed packer design.

Bioinspired ultra-low fouling coatings on medical devices to prevent device-associated infections and thrombosis

Addressing thrombosis and biofouling of indwelling medical devices within healthcare institutions is an ongoing problem. In this work, two types of ultra-low fouling surfaces (i.e., superhydrophobic and lubricant-infused slippery surfaces) were fabricated to enhance the biocompatibility of commercial medical grade silicone rubber (SR) tubes that are widely used in clinical care. The superhydrophobic (SH) coatings on the tubing substrates were successfully created by dip-coating in superhydrophobic paints consisting of polydimethylsiloxane (PDMS), perfluorosilane-coated hydrophobic zinc oxide (ZnO) and copper (Cu) nanoparticles (NPs) in tetrahydrofuran (THF). The SH surfaces were converted to lubricant-infused slippery (LIS) surfaces through the infusion of silicone oil. The anti-biofouling properties of the coatings were investigated by adsorption of platelets, whole blood coagulation, and biofilm formation in vitro. The results revealed that the LIS tubes possess superior resistance to clot formation and platelet adhesion than uncoated and SH tubes. In addition, bacterial adhesion was investigated over 7 days in a drip-flow bioreactor, where the SH-ZnO-Cu tube and its slippery counterpart significantly reduced bacterial adhesion and biofilm formation of Escherichia coli relative to control tubes (>5 log10 and >3 log10 reduction, respectively). The coatings also demonstrated good compatibility with fibroblast cells. Therefore, the proposed coatings may find potential applications in high-efficiency on-demand prevention of biofilm and thrombosis formation on medical devices to improve their biocompatibility and reduce the risk of complications from medical devices.

Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy

Objectives:Choroidal hemorrhages (CH) result from rupture of choroidal vessels leading to extravasation of blood into the suprachoroidal space. In this study, we aimed to understand the hemodynamics of CH by developing a purpose-built scale model of the choroidal vasculature and calculating stress levels in the model under different conditions.Materials and Methods:We modeled the choroidal vasculature using a rubber tube 10 cm in length and 1 cm in diameter that was wrapped with conductive thread to enable the measurement of stress at the walls of the tube. Stress levels across the tube were continuously measured under different systemic intravascular blood pressure levels (IVP), intraocular pressure (IOP) levels, and distortion.Results:Stress values across the choroidal vessel model correlated negatively with IOP and positively with IVP and distortion. All correlations were statistically significant (p<0.05) and were stronger when the model was filled with expansile tamponade compared to non-expansile tamponades. Distortion showed the strongest correlation in terms of increasing stress across the model, while IVP showed stronger correlation compared to IOP. Raising IOP to counteract the stress in the model was effective when the stress in the model was secondary to increased IVP, but this approach was not effective when the stress in the model was caused by distortion.Conclusion:Excessive distortion of the globe during surgical maneuvers could be the primary reason for the rarely observed intraoperative CH. Non-expansile ocular tamponade provides better support for the vascular bed against CH and should be the recommended choice of tamponade in patients with existing CH. Increasing IOP excessively is of limited effect in preventing CH in vessels that are under stress as a result of distorting surgical maneuvers.