An Experimental Study on the Effect of Compression Force Uniformity in Electrosurgical Tissue Welding

2016 ◽  
Author(s):  
Xiaoran Li ◽  
Russell Borduin ◽  
Roland Chen ◽  
Wei Li
Keyword(s):  
Power Distribution ◽  
Electrical Power ◽  
Welding Process ◽  
Compression Force ◽  
Uniform Compression ◽  
Tissue Impedance ◽  
Tissue Welding ◽  
The Difference ◽  
Joint Quality ◽  
Tissue Mimicking Material

Bipolar forceps are a type of electrosurgical device (ESD) widely used for tissue welding in modern surgeries. ESDs have many advantages over traditional surgical tools including reduced blood loss, improved efficiency and lower surgeon fatigue. However, these devices suffer from tissue sticking and damage due to overheating which leads to poor tissue joint quality. The problem is potentially caused by uneven power distribution due to non-uniform compression applied by the bipolar forceps. In this study, the effect of compression force uniformity was investigated with an experimental setup to achieve a uniform and consistent compression force at the jaws of bipolar forceps. Comparative tissue welding experiments were conducted under both uniform and non-uniform compression force conditions with tissue mimicking material. In situ welding process parameters including compression force, electrical voltage, and current were collected and analyzed to understand the effect of compression force uniformity. Comparing the uniform to non-uniform compression force cases, the results indicate that tissue impedance is lower due to increased tissue contact area; the electrical power is initially higher during the first few milliseconds, but becomes lower for the rest of the welding process recorded. The experimental device developed in this study provides an important platform to understand the difference of tissue welding process under uniform and non-uniform compression force conditions.

The Effect of Compression Force Uniformity on Bipolar Tissue Welding

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Xiaoran Li ◽  
Russel Borduin ◽  
Roland K. Chen ◽  
Wei Li
Keyword(s):  
Power Distribution ◽  
Electrical Power ◽  
Welding Process ◽  
Compression Force ◽  
Tissue Impedance ◽  
Tissue Welding ◽  
The Difference ◽  
Joint Quality ◽  
Tissue Mimicking Material

Bipolar forceps are a type of electrosurgical device (ESD) widely used for tissue welding in modern surgeries. ESDs have many advantages over traditional surgical tools including reduced blood loss, improved efficiency, and lower surgeon fatigue. However, these devices suffer from tissue sticking and damage due to overheating which leads to poor tissue joint quality. The problem is potentially caused by uneven power distribution due to nonuniform compression applied by the bipolar forceps. In this study, the effect of compression force uniformity was investigated with an experimental setup to achieve a uniform and consistent compression force at the jaws of bipolar forceps. Comparative tissue welding experiments were conducted under both uniform and nonuniform compression force conditions with tissue mimicking material. In situ welding process parameters including compression force, electrical voltage, and current were collected and analyzed to understand the effect of compression force uniformity. The results indicate that tissue impedance is lower due to increased tool–tissue contact area; the electrical power is initially higher during the first few milliseconds of welding. The experimental device developed in this study provides an important platform to understand the difference of tissue welding process under uniform and nonuniform compression force conditions.

scholarly journals Non-isolated load sharing direct current system operation with use of the auctioneering diodes

2019 ◽  
Vol 28 ◽  
pp. 01037 ◽  
Author(s):  
Maciej Kozak
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Heat Dissipation ◽  
Current System ◽  
Electrical Power ◽  
Experimental System ◽  
Laboratory System ◽  
Simulation Studies ◽  
Power Distribution System ◽  
Electrical Systems

The paper presents the background and results of numerical simulation and experimental research of a system using auctioneering diodes used to distribute the electrical power between two power converters connected with intermediate circuits in parallel, direct connection. Presented non-isolated power distribution system which utilizes blocking diodes placed in DC branches are used in the selected ship's electrical systems, however, they create problems related to control and handling ground faults. Another issue occurring during the operation of this type of systems is increased heat dissipation while diodes switching. Selected problems related to the operation of experimental system have been identified by means of simulation studies and experiments carried out in a 11 kVA laboratory system and the theoretical basis along with results are provided in the article.

scholarly journals Investigation of the Impact of Large-Scale Integration of Electric Vehicles for a Swedish Distribution Network

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4717 ◽  
Author(s):  
Sylvester Johansson ◽  
Jonas Persson ◽  
Stavros Lazarou ◽  
Andreas Theocharis
Keyword(s):  
Electric Vehicles ◽  
Power Distribution ◽  
Large Scale ◽  
Electrical Power ◽  
Distribution Network ◽  
Transport Sector ◽  
Smart Charging ◽  
Large Scale Integration ◽  
Scale Integration ◽  
The Impact

Social considerations for a sustainable future lead to market demands for electromobility. Hence, electrical power distribution operators are concerned about the real ongoing problem of the electrification of the transport sector. In this regard, the paper aims to investigate the large-scale integration of electric vehicles in a Swedish distribution network. To this end, the integration pattern is taken into consideration as appears in the literature for other countries and applies to the Swedish culture. Moreover, different charging power levels including smart charging techniques are examined for several percentages of electric vehicles penetration. Industrial simulation tools proven for their accuracy are used for the study. The results indicate that the grid can manage about 50% electric vehicles penetration at its current capacity. This percentage decreases when higher charging power levels apply, while the transformers appear overloaded in many cases. The investigation of alternatives to increase the grid’s capabilities reveal that smart techniques are comparable to the conventional re-dimension of the grid. At present, the increased integration of electric vehicles is manageable by implementing a combination of smart gird and upgrade investments in comparison to technically expensive alternatives based on grid digitalization and algorithms that need to be further confirmed for their reliability for power sharing and energy management.

Cold Metal Transfer Spot Joining of AA6061-T6 to Galvanized DP590 Under Different Modes

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
HaiYang Lei ◽  
YongBing Li ◽  
Blair E. Carlson ◽  
ZhongQin Lin
Keyword(s):  
Heat Input ◽  
Mechanical Performance ◽  
Welding Process ◽  
High Strength ◽  
Metal Transfer ◽  
Cold Metal Transfer ◽  
Spot Joining ◽  
Predrilled Hole ◽  
Joint Quality ◽  
Cold Metal

In order to meet the upcoming regulations on greenhouse gas emissions, aluminum use in the automotive industry is increasing. However, this increase is now seen as part of a multimaterial strategy. Consequently, dissimilar material joints are a reality, which poses significant challenges to conventional fusion joining processes. To address this issue, cold metal transfer (CMT) spot welding process was developed in the current study to join aluminum alloy AA6061-T6 as the top sheet to hot dip galvanized (HDG) advanced high strength steel (AHSS) DP590 as the bottom sheet. Three different welding modes, i.e., direct welding (DW) mode, plug welding (PW) mode, and edge plug welding (EPW) mode were proposed and investigated. The DW mode, having no predrilled hole in the aluminum top sheet, required concentrated heat input to melt through the Al top sheet and resulted in a severe tearing fracture, shrinkage voids, and uneven intermetallic compounds (IMC) layer along the faying surface, leading to poor joint properties. Welding with the predrilled hole, PW mode, required significantly less heat input and led to greatly reduced, albeit uneven, IMC layer thickness. However, it was found that the EPW mode could homogenize the welding heat input into the hole and thus produce the most stable welding process and best joint quality. This led to joints having an excellent joint morphology characterized by the thinnest IMC layer and consequently, best mechanical performance among the three modes.

scholarly journals Electrical Power Distribution

Nature ◽  
1900 ◽  
Vol 62 (1604) ◽  
pp. 296-300
Author(s):  
W. E. AYRTON
Keyword(s):  
Power Distribution ◽  
Electrical Power

Investigation of the Cleaning and Welding Steps From the Friction Element Welding Process

2017 ◽  
Author(s):  
Jamie D. Skovron ◽  
Brandt J. Ruszkiewicz ◽  
Laine Mears ◽  
Tim Abke ◽  
Ankit Varma ◽  
...  
Keyword(s):  
Weld Zone ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Process Time ◽  
Friction Element ◽  
Joint Quality ◽  
Head Height ◽  
Friction Element Welding ◽  
Step Parameters

The requirement of increased fuel economy standards has forced automakers to incorporate multi-materials into their current steel dominant vehicles in order to lightweight their fleets. Technologies such as Self Piercing Rivets and Flow Drill Screws are currently implemented for joining aluminum to high-strength steels but only one-technology is viable for joining aluminum to ultra-high-strength steels without pre-holes, namely Friction Element Welding. This study is aimed at investigating how variations in the cleaning and welding steps of the Friction Element Welding process influence joint quality. A design of experiment was conducted to understand the influence of key process parameters (endload, spindle RPM, and relative distance) during these steps on the pre-defined joint quality metrics of head height, weld zone diameter, under-head fill area, temperature, and microhardness. It is found that cleaning step parameters have the greatest influence on process time and energy consumption, while welding step parameters greatly influence maximum torque on the element, head height, and underhead fill, with both cleaning force and weld force influencing weld diameter, all parameters influence temperature.

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