Dynamic Impedance Monitoring for Large Diameter Vessel Sealing Using Bipolar Electrosurgery

2020 ◽  
Vol 14 (2) ◽  
Author(s):  
Xiaoran Li ◽  
Wei Li ◽  
Che-Hao Yang ◽  
Roland K. Chen
Keyword(s):  
Large Diameter ◽  
Electrical Power ◽  
Heating Process ◽  
Tissue Impedance ◽  
Vessel Sealing ◽  
Dynamic Impedance ◽  
Element Simulation ◽  
Normal Human ◽  
In The Beginning ◽  
Bipolar Electrosurgery

Abstract Vessel sealing using bipolar electrosurgery is becoming a common practice in modern operating rooms. Despite all the advantages such as faster operation, less bleeding, and shorter postsurgery recovery time, side effects including sticking, charring, and rebleeding still occur, leading to increased surgery time and sometimes fatal complications. Tissue impedance during the electrosurgical process has been used to determine the electrical power of the process. However, little has been done to understand the dynamic tissue impedance and its effectiveness in monitoring the vessel sealing process. Moreover, the samples used in previous studies all had small diameters of 2–5 mm. In this study, an experimental setup was developed to perform vessel sealing tests using large-diameter blood vessel samples with mimicking blood flow. The tissue impedance during the heating process was obtained. Burst pressures after sealing were measured. A finite element simulation model was developed to understand the dynamic impedance behavior. It is seen that the tissue impedance increases rapidly in the beginning of the heating process and remains at a level that is several orders of magnitude higher than the initial value. This rapid impedance increase indicates protein denaturing, thus can be used to monitor the electrosurgical vessel sealing process. An impedance-based monitoring algorithm was developed, with which a burst pressure at least twice the normal human systolic blood pressure was achieved.

Dynamic Impedance Monitoring of Large Diameter-Vessel Sealing in Bipolar Electrosurgeries

2019 ◽  
Author(s):  
Xiaoran Li ◽  
Che-Hao Yang ◽  
Roland K. Chen ◽  
Wei Li
Keyword(s):  
Ex Vivo ◽  
Large Diameter ◽  
Small Diameter ◽  
Operation Time ◽  
Tissue Impedance ◽  
Fea Model ◽  
Post Surgery ◽  
Vessel Sealing ◽  
Dynamic Impedance ◽  
Impedance Monitoring

Abstract Vessel sealing with a bipolar electrosurgical device has become a common practice in modern operation rooms. Despite all the advantages, such as easier operation, less bleeding, and shorter post-surgery recovery time, side effects including sticking, charring, and rebleeding, often occur, leading to increased operation time and sometimes complications that are potentially fatal. Tissue impedance during the electrosurgical procedure has been used to improve the surgical outcome However, this method has only been effective for small-diameter vessels of 3–5 mm. Overall, little is found in literature on dynamic impedance monitoring of blood vessel sealing using bipolar electrosurgical devices. In this study, an experimental setup was designed and built to perform vessel sealing tests on large-diameter blood vessels with mimicking blood flow. Ex vivo porcine carotid artery samples with a diameter about 7 mm were used. Burst pressures after sealing were measured. It was found that the tissue impedance started with an initial decrease, followed by a rapid increase, and ended with a plateau that was orders of magnitude higher than the initial impedance. The rapid increase of impedance provides indication of protein denaturing, thus the seal completion. This feature was used to monitor the electrosurgical vessel sealing process. It is shown that a burst pressure at least twice the normal human systolic blood pressure can be achieved with heating until the maximum tissue impedance is reached. A FEA model was developed in COMSOL to understand the dynamic impedance behavior in the vessel sealing process.

scholarly journals An Experimental Study on Bipolar Tissue Hemostasis and Its Dynamic Impedance

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Xiaoran Li ◽  
Roland Chen ◽  
Wei Li
Keyword(s):  
Minimal Invasive ◽  
Heating Power ◽  
Heating Process ◽  
Medical Procedure ◽  
Quality Prediction ◽  
Seal Failure ◽  
Vessel Sealing ◽  
Dynamic Impedance ◽  
Tissue Zone ◽  
Compression Level

Abstract Bipolar tissue hemostasis is a medical procedure where high frequency alternating current is applied to biological tissue for wound closing and blood vessel sealing through heating. The process is often performed with a set of laparoscopic forceps in a minimal invasive surgery to achieve less bleeding and shorter recovery time. However, problems such as tissue sticking, thermal damage, and seal failure often occur and need to be solved before the process can be reliably used in more surgical procedures. In this study, experiments were conducted to examine process parameters and the dynamic behavior of bipolar heating process through electrical impedance measurements. The effects of electrode compression level, heating power, and time are analyzed. Heating energy and bio-impedance are evaluated for quality prediction. Tissue sticking levels were correlated to the size of denatured tissue zone. It is found that tissue denaturation starts from the center of the heated region. Dynamic impedance reveals the stages of tissue hemostasis process. However, it is strongly affected by the compression level and heating power. Existing criteria for quality prediction and control using the heating energy and minimal impedance are not reliable. The size of denatured tissue zone can be predicted with the heating energy; however, the prediction is strongly dependent on the compression level. To avoid sticking, a low power and low compression level should be used for the same denatured tissue zone size.

Vessel-Sealing Capability of Novel Microwave Sealer: Experimental Study in Animal Models

2020 ◽  
pp. 155335062093786
Author(s):  
Khiem Tran Dang ◽  
Shigeyuki Naka ◽  
Atsushi Yamada ◽  
Ken-ichi Mukaisho ◽  
Tohru Tani
Keyword(s):  
Thermal Damage ◽  
Ex Vivo ◽  
Vessel Diameter ◽  
Heating Process ◽  
Damage Evaluation ◽  
Vessel Sealing ◽  
Surgical Devices ◽  
Harmonic Focus ◽  
Thermal Spread

Background. Ultrasonically activated dissectors (UADs) and radiofrequency-based devices have been considered excellent surgical devices because of their reliability and flexibility. Meanwhile, microwave-based devices have demonstrated potential with their unique heating mechanism. This study aims to compare the sealing function of a newly invented forceps-like microwave sealer (MS) with that of currently available UADs. Materials and Methods. MS and 2 examples of UADs (Harmonic Focus+ [HF+] and Sonicision [SNC]) were employed to perform mesenterectomies (in vivo) and sealing sizable vessels (ex vivo). Vessel diameter, seal time, burst pressure (BP), sealing completion, and instrument sticking were recorded. The samples underwent histological investigation for thermal damage evaluation. Results. During mesenterectomies, MS required 3 seconds and 30 W to secure a complete seal. The BP achieved by the MS seal was higher than that of HF+ and SNC on arteries (851 ± 203.7 vs 682.4 ± 287.3, P < .05; vs 833.1 ± 251.2 mmHg, P = .4523, respectively) but was not statistically different on veins (324.9 ± 203.5 vs 460.1 ± 320.3 vs 508.3 ± 350.7 mmHg, P = .215). In all trials, MS caused less sticking but exhibited similar heat-induced alterations to UADs. MS’s thermal spread was not statistically more extended than that of UADs on either arteries or veins. Conclusions. MS was capable of not only sealing tiny vessels but also achieving high-pressure endurance on sizable vessels. Its forceful grasping and synchronous heating process helped create solid stumps with an acceptable thermal spread.

scholarly journals Parameter Optimization and Prediction Model of Induction Heating for Large-Diameter Pipe

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiurong Fang ◽  
Jia Lu ◽  
Junfeng Wang ◽  
Jinhui Yang
Keyword(s):  
Prediction Model ◽  
Induction Heating ◽  
Process Parameters ◽  
Pipeline Steel ◽  
Large Diameter ◽  
Outer Wall ◽  
Design Parameters ◽  
Heating Process ◽  
Influence Of Process Parameters ◽  
Heating Device

The parameters of induction heating of large-diameter pipes have a direct effect on the final processing quality of the elbow, and the complexity of multifield coupling of magnetothermal force in induction heating can make it impossible to quantitatively optimize the design parameters of the induction heating device. In this paper, X80 pipeline steel induction heating is taken as the research object, and a corresponding numerical model is established. The influence of induction heating process parameters on the heating temperature of pipeline steel under the skin effect is determined. First, the influence of process parameters on the heating effect of pipeline steel is quantified by orthogonal test. Then, taking the optimum temperature difference between the inner and outer wall of X80 pipeline steel during the induction heating process as a target, the optimal process parameter set of the pipe induction heating is determined by using neural network genetic algorithm. Finally, comparing the relevant test criteria of the regression equation, the optimum mathematical prediction model of the outer wall temperature of the pipe induction heating process is obtained, which provides a theoretical basis for optimization of the process parameters of the pipe-based induction heating device.

The Die Design of Large Diameter Tee Multi-Pass Extrusion Process

2011 ◽  
Vol 194-196 ◽  
pp. 2199-2203
Author(s):  
Jian Zhang ◽  
Tan Li ◽  
Liang Chu ◽  
Da Sen Bi
Keyword(s):  
Large Diameter ◽  
Equivalent Stress ◽  
Extrusion Process ◽  
Equivalent Strain ◽  
Simulation Software ◽  
Die Design ◽  
State Variables ◽  
Element Simulation ◽  
Deformation Stress ◽  
First Contact

Finite element simulation software Deform-3D on large-diameter multi-pass three-way pipe to simulate the extrusion process, the equivalent stress, equivalent strain and load were analyzed. The simulation results show that with the increase of processing pass, deformation process becomes complex, forming more difficult, the value of the state variables are increasing; in the extrusion process, the mold first contact with the billet and extruded convex hull area of the site, compared to other regions, plastic deformation, stress concentration and large, with the mold closed, the force to uniform .The results are well shown that it could provide a theoretical basis to the practical industrial production.

scholarly journals Biocontrol of Escherichia coli O157:H7 in ready-to-eat salad using a lytic bacteriophage

2017 ◽  
Vol 73 (7) ◽  
pp. 422-424
Author(s):  
Gizem Cufaoglu ◽  
Bahar Onaran Naim Deniz Ayaz ◽  
Muammer Goncuoglu ◽  
Fatma Seda Ormancı
Keyword(s):  
Biocontrol Agent ◽  
Foodborne Pathogen ◽  
Storage Period ◽  
Storage Conditions ◽  
Heating Process ◽  
Lytic Bacteriophage ◽  
E Coli ◽  
C Storage ◽  
Life Threatening ◽  
In The Beginning

E. coli O157:H7 is a life threatening foodborne pathogen associated with thousands of infections. Controlling such bacterial pathogens in raw and ready-to-eat foods has gained urgency with each passing day. The use of specific virulent bacteriophages as a biocontrol agent on minimally processed foods is an effective, natural and non-destructive treatment. This study was aimed at determining the efficiency of a lytic bacteriophage against E. coli O157:H7 in ready-to-eat salads. For this purpose, E. coli O157:H7 NCTC 12900 (EC00) and nalidixic acid resistant E. coli O157:H7 ATCC 43895 (NA-EC95) were used as the model bacterium in decontamination trials of mayonnaise based ready-to-eat salads which are consumed without any heating process and include beans, carrots, potatoes, pickled cucumbers and salami. A previously described phage M8AEC16 which was classified in Myoviridae family was used as the biocontrol agent. The highest reductions were observed at 22°C storage conditions. Reductions reaching up to 2.7 log cfu/g of viable E. coli O157:H7 counts were observed in the beginning of the storage period. The findings of the study showed that phage M8AEC16 can be used as a biocontrol agent in the decontamination of E. coli O157:H7 in such mayonnaise based ready-to-eat salads.

scholarly journals PERANCANGAN PEMANAS AIR OHMIK SEDERHANA BERBAHAN DASAR SENDOK MAKAN LOGAM

2018 ◽  
Vol 8 (1) ◽  
pp. 22-31
Author(s):  
Hazairin Nikmatul Lukma
Keyword(s):  
Energy Efficiency ◽  
Data Analysis ◽  
Electrical Power ◽  
Electrical Energy ◽  
Heating Process ◽  
Water Heater ◽  
Ohm’S Law ◽  
Current Limiting ◽  
Heating Water ◽  
Further Development

Penelitian ini bertujuan untuk mengetahui hasil pemanfaatan sendok makan logam yang digunakan sebagai pemanas air menggunakan prinsip Ohmik, yang didesain sedemikian rupa sehingga sendok makan dapat berfungsi sebagai elektroda. Ketika dua buah sendok makan dengan jarak tertentu yang dapat diatur jaraknya dialiri arus, maka akan dihasilkan kalor yang mampu meningkatkan suhu air dalam suatu wadah yang terbuat dari isolator, sebagaimana prinsip Hukum Ohm. Jarak kedua sendok dapat diatur, dimana semakin dekat jarak antara dua sendok, makin cepat proses pemanasan air. Penelitian dilakukan di Laboratorium Teknik Universitas Islam Balitar pada bulan April hingga Juni tahun 2017. Hasil analisis data menunjukkan bahwa semakin besar antara kedua sendok, makin lama proses pemanasan, namun daya yang diperlukan lebih rendah. Sedangkan ketika jarak antara kedua sendok dibuat lebih dekat, proses pemanasan berjalan lebih cepat, akan tetapi daya listrik yang diperlukan juga semakin besar. Nilai efisiensi energi listrik dari pemanas air ohmik diperoleh sebesar 90%. Nilai efsiensi ini tidak terlalu tinggi dikarenakan selama proses pemanasan, daya listrik yang dibutuhkan terus meningkat. Untuk pengembangan selanjutnya, desain alat pemanas air ini dapat ditambah komponen pembatas arus, sehingga daya listrik yang digunakan dapat terkontrol.This research aims to determine the results of the use of metal tablespoons used as a water heater using Ohmik principle, which is designed in such a way that the tablespoons can function as an electrode. When two tablespoon with a certain distance can be adjusted the distance flow, the heat will be produced that can increase the temperature of water in a container made of insulators, as the principle of Ohm's Law. Spacing of two spoons can be adjusted, where the closer the distance between two spoons, the faster the process of heating water. The research was conducted at the Technical Laboratory of Islamic University of Balitar in April to June 2017. The result of data analysis showed that the bigger between the two spoons, the longer the heating process, but the required power is lower. Meanwhile, when the distance between the two spoons is made closer, the heating process runs faster, but the power required is also greater. The value of the electrical energy efficiency of the ohmic water heater is 90%. The value of this efficiency is not too high because during the heating process, the electrical power required continues to increase. For further development, the design of this water heater can be added current limiting components, so that the electrical power used can be controlled.

scholarly journals Forecasting the strength properties of the large diameter polymer rebar based on the experimental analysis of its structure

2020 ◽  
Vol 313 ◽  
pp. 00036
Author(s):  
Andrey Benin ◽  
Artem Semenov ◽  
Maxim Lobachev ◽  
Galina Bogdanova
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Large Diameter ◽  
Strength Properties ◽  
Matrix Resin ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Element Simulation ◽  
Mass Fractions ◽  
Component Material

Fiber reinforced plastic bar (FRP-rebar) is a two-component material consisting of polymer matrix (resin) and reinforcing filler (roving). Large-scale implementation of FRP-rebar and improvement of its manufacturing process have resulted in larger bar diameters. However, it is extremely complicated or even impossible to experimentally determine the mechanical properties of this kind of rebar when using standard testing machines. The reason for this is the low cross-direction strength of the rebar. The purpose of the research is to determine the elastic and strength properties of large diameter FRP-rebar by means of finite-element simulation as well as to analyze the influence of the components’ mass fractions and grooving on the mechanical properties being studied. In order to specify the parameters of the FE simulation model the authors performed some supplementary tests aimed at determining the structure of the fiber. A comparative study of the obtained numerical results against the experimental data is presented in the paper.

scholarly journals An Analytical Method for the Longitudinal Vibration of a Large-Diameter Pipe Pile in Radially Heterogeneous Soil Based on Rayleigh–Love Rod Model

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1442
Author(s):  
Zhimeng Liang ◽  
Chunyi Cui ◽  
Kun Meng ◽  
Yu Xin ◽  
Huafu Pei ◽  
...  
Keyword(s):  
Analytical Solution ◽  
Analytical Method ◽  
Longitudinal Vibration ◽  
Large Diameter ◽  
Pipe Pile ◽  
Large Diameter Pipe ◽  
Dynamic Impedance ◽  
Diameter Pipe ◽  
Rod Model ◽  
Heterogeneous Soil

Based on the Rayleigh–Love rod model and Novak’s plane-strain theory, an analytical method for the longitudinal vibration of a large-diameter pipe pile in radially heterogeneous soil is proposed. Firstly, the governing equations of the pile-soil system are established by taking both the construction disturbance effect and transverse inertia effect into account. Secondly, the analytical solution of longitudinal dynamic impedance at the pile top can be achieved by using Laplace transform and complex stiffness transfer techniques. Thirdly, the present analytical solution for dynamic impedance can also be performed in contrast with the existing solution to examine the correctness of the analytical method in this work. Further, the effect of pile Poisson’s ratio, pile diameter ratio as well as soil disturbed degree on the dynamic impedance are investigated. The results demonstrate that the Rayleigh–Love rod is appropriate for simulating the vibration of a large-diameter pipe pile in heterogeneous soils.

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