scholarly journals Thermal effects of percutaneous application of plasma/radiofrequency energy on porcine dermis and fibroseptal network

2020 ◽  
Author(s):  
Paul G. Ruff
Keyword(s):  
Thermal Effects ◽  
Radiofrequency Energy ◽  
Porcine Dermis

Radiofrequency Thermal Effects on the Human Meniscus: An in Vitro Study of Systems with Monopolar and Bipolar Electrodes

2003 ◽  
Vol 31 (2) ◽  
pp. 253-256 ◽  
Author(s):  
C. Thomas Vangsness ◽  
John D. Polousky ◽  
Andrew B. Parkinson ◽  
Thomas P. Hedman
Keyword(s):  
Thermal Effects ◽  
Thermal Damage ◽  
Energy Output ◽  
Radiofrequency Energy ◽  
Bipolar Electrodes ◽  
Application Systems ◽  
Meniscal Tissue ◽  
Individual System ◽  
Energy Application ◽  
The Individual

Background: No data exist on the cutting efficiency of monopolar versus bipolar radiofrequency energy application systems on human meniscal tissue. Purpose: To compare the effects of monopolar and bipolar thermal energy systems on human meniscal tissue. Study Design: Controlled laboratory study. Methods: Fresh-frozen menisci were cut in cross-section into 180 pie-shaped specimens. A specially designed jig was used to consistently apply radiofrequency energy to the tissue under a constant 30-g force. Three different systems were tested at the low, middle, and high ranges, with application times of 1 and 3 seconds. Thermal effects were measured by image analysis microscopy. Results: No significant differences in thermal effects were found with respect to energy output for each system. Both the individual system tested and the application time had statistically significant effects on thermal damage, with the individual system tested having a greater effect. The mean depths of thermal change produced by the Mitek (bipolar) device were 564 and 648 μm at 1 and 3 seconds applications, respectively. The Arthrocare device (bipolar) produced depths of 1444 and 1697 μm at 1 and 3 seconds. The Oratec device (monopolar) produced depths of 895 and 1057 μm, respectively. Conclusions: A differential thermal effect was created in the meniscal tissue by three commercially available radiofrequency systems. Within the parameters of the experiment, all three systems limited thermal damage to a depth of less than 2 mm. The results appeared to depend more on the particular system used, not whether it had monopolar or bipolar electrodes. Clinical Relevance: These data imply reasonably safe (less than 2 mm) thermal changes in the meniscus after radiofrequency energy application from these three systems.

Thermal Considerations in Lens Regulator Systems

1970 ◽  
Vol 28 ◽  
pp. 358-359
Author(s):  
K.C. Newton
Keyword(s):  
Electron Microscope ◽  
Thermal Effects ◽  
Environmental Control ◽  
Reference Networks ◽  
Better Than

Thermal effects in lens regulator systems have become a major problem with the extension of electron microscope resolution capabilities below 5 Angstrom units. Larger columns with immersion lenses and increased accelerating potentials have made solutions more difficult by increasing the power being handled. Environmental control, component choice, and wiring design provide answers, however. Figure 1 indicates with broken lines where thermal problems develop in regulator systemsExtensive environmental control is required in the sampling and reference networks. In each case, stability better than I ppm/min. is required. Components with thermal coefficients satisfactory for these applications without environmental control are either not available or priced prohibitively.

Direct measurement of electron-diffraction-pattern intensities using an energy loss spectrometer

1989 ◽  
Vol 47 ◽  
pp. 668-669
Author(s):  
A. G. Jackson ◽  
M. Rowe
Keyword(s):  
Thermal Effects ◽  
Dynamic Range ◽  
Scattering Amplitude ◽  
Dynamical Theory ◽  
Site Symmetry ◽  
Proof Of Concept ◽  
Parallel Acquisition ◽  
Kinematic Approximation ◽  
Speed Up ◽  
Structure Calculations

Diffraction intensities from intermetallic compounds are, in the kinematic approximation, proportional to the scattering amplitude from the element doing the scattering. More detailed calculations have shown that site symmetry and occupation by various atom species also affects the intensity in a diffracted beam. [1] Hence, by measuring the intensities of beams, or their ratios, the occupancy can be estimated. Measurement of the intensity values also allows structure calculations to be made to determine the spatial distribution of the potentials doing the scattering. Thermal effects are also present as a background contribution. Inelastic effects such as loss or absorption/excitation complicate the intensity behavior, and dynamical theory is required to estimate the intensity value.The dynamic range of currents in diffracted beams can be 104or 105:1. Hence, detection of such information requires a means for collecting the intensity over a signal-to-noise range beyond that obtainable with a single film plate, which has a S/N of about 103:1. Although such a collection system is not available currently, a simple system consisting of instrumentation on an existing STEM can be used as a proof of concept which has a S/N of about 255:1, limited by the 8 bit pixel attributes used in the electronics. Use of 24 bit pixel attributes would easily allowthe desired noise range to be attained in the processing instrumentation. The S/N of the scintillator used by the photoelectron sensor is about 106 to 1, well beyond the S/N goal. The trade-off that must be made is the time for acquiring the signal, since the pattern can be obtained in seconds using film plates, compared to 10 to 20 minutes for a pattern to be acquired using the digital scan. Parallel acquisition would, of course, speed up this process immensely.

Experimental Study of Thermal Effects in the Sterilization of Disperse Systems

2001 ◽  
Vol 32 (4-6) ◽  
pp. 5
Author(s):  
A. A. Dolinsky ◽  
Yu. A. Shurchkova ◽  
B. I. Basok ◽  
T. S. Ryzhkova
Keyword(s):  
Experimental Study ◽  
Thermal Effects ◽  
Disperse Systems

Use of Second Harmonic and Thermal Effects of Laser Voltage Probing for Better Fault Isolation

2016 ◽  
Author(s):  
Ramya Yeluri ◽  
Ravishankar Thirugnanasambandam ◽  
Cameron Wagner ◽  
Jonathan Urtecho ◽  
Jan M. Neirynck
Keyword(s):  
Duty Cycle ◽  
Thermal Effects ◽  
Second Harmonic ◽  
Fault Isolation ◽  
Advanced Technology ◽  
Temperature Dependent ◽  
First Case ◽  
Improve Accuracy ◽  
Degradation Monitoring ◽  
Technology Nodes

Abstract Laser voltage probing (LVP) has been extensively used for fault isolation over the last decade; however fault isolation in practice primarily relies on good-to-bad comparisons. In the case of complex logic failures at advanced technology nodes, understanding the components of the measured data can improve accuracy and speed of fault isolation. This work demonstrates the use of second harmonic and thermal effects of LVP to improve fault isolation with specific examples. In the first case, second harmonic frequency is used to identify duty cycle degradation. Monitoring the relative amplitude of the second harmonic helps identify minute deviations in the duty cycle with a scan over a region, as opposed to collecting multiple high resolution waveforms at each node. This can be used to identify timing degradation such as signal slope variation as well. In the second example, identifying abnormal data at the failing device as temperature dependent effect helps refine the fault isolation further.

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