scholarly journals Dynamic evaluation of renal electrolyte gradient by in situ tissue impedance studies

1983 ◽  
Vol 24 (6) ◽  
pp. 800-803 ◽  
Author(s):  
Janusz Sadowski ◽  
Ewa Portalska ◽  
Jadwiga Zwolińska
Keyword(s):  
Tissue Impedance ◽  
Dynamic Evaluation

In Situ Measurement of Tissue Impedance Using an Inductive Coupling Interface Circuit

2013 ◽  
Vol 7 (3) ◽  
pp. 225-235 ◽  
Author(s):  
Hung-Wei Chiu ◽  
Jia-min Chuang ◽  
Chien-Chi Lu ◽  
Wei-Tso Lin ◽  
Chii-Wann Lin ◽  
...  
Keyword(s):  
In Situ Measurement ◽  
Inductive Coupling ◽  
Tissue Impedance ◽  
Interface Circuit

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.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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