Electric signal detection at the early stage of laser ablation in air

1999 ◽  
Vol 86 (5) ◽  
pp. 2812-2817 ◽  
Author(s):  
Y. F. Lu ◽  
M. H. Hong
Keyword(s):  
Laser Ablation ◽  
Signal Detection ◽  
Early Stage ◽  
Electric Signal

scholarly journals Phase 2 Open-Label Trial Investigating Percutaneous Laser Ablation for Treatment of Early-Stage Breast Cancer: MRI, Pathology, and Outcome Correlations

2018 ◽  
Vol 25 (10) ◽  
pp. 2958-2964 ◽  
Author(s):  
Barbara Schwartzberg ◽  
John Lewin ◽  
Osama Abdelatif ◽  
Jacqueline Bernard ◽  
Hanadi Bu-Ali ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Ductal Carcinoma ◽  
Early Stage ◽  
False Negative ◽  
Mri Imaging ◽  
Open Label ◽  
Invasive Ductal Breast Carcinoma ◽  
Intention To Treat ◽  
Ki67 Staining ◽  
Percutaneous Laser Ablation

Abstract Background An institutional review board-approved, multicenter clinical trial was designed to determine the efficacy and outcome of percutaneous laser ablation (PLA) in the treatment of invasive ductal breast carcinoma (IDC). Post-ablation magnetic resonance imaging (MRI) was compared with surgical pathology in evaluation of residual post-ablation IDC and ductal carcinoma in situ. Methods Patients with a single focus of IDC 20 mm or smaller by pre-ablation MRI were treated with PLA. The patients underwent a 28-day post-ablation MRI, followed by surgical resection. Cell viability criteria were applied to pre- and post-ablation pathology specimens, which evaluated hematoxylin–eosin (H&E), cytokeratin (CK) 8/18, estrogen receptor, and Ki67 staining patterns. Results In this study, 61 patients were reported as the intention-to-treat cohort for determination of PLA efficacy. Of these 61 patients, 51 (84%) had complete tumor ablation confirmed by pathology analysis. One subject’s MRI imaging was not performed per protocol, which left 60 subjects evaluable for MRI pathology correlation. Five patients (8.3%) had residual IDC shown by both MRI and pathology. Post-ablation discordance was noted between MRI and pathology, with four patients (6.7%) false-positive and four patients (6.7%) false-negative. The negative predictive value (NPV) of MRI for all the patients was 92.2% (95% confidence interval [CI], 71.9–91.9%). Of the 47 patients (97.9%) with tumors 15 mm or smaller, 46 were completely ablated, with an MRI NPV of 97.7% (95% CI, 86.2–99.9%). Conclusions Percutaneous laser ablation is a potential alternative to surgery for treatment of early-stage IDC. Strong correlations exist between post-ablation MRI and pathologic alterations in CK8/18, ER, and Ki67 staining.

Early-Stage Evolution of Electrons Emitted From Metal Target Surface During Ultrashort Laser Ablation in Vacuum

2011 ◽  
Author(s):  
Sha Tao ◽  
Benxin Wu
Keyword(s):  
Heat Transfer ◽  
Laser Ablation ◽  
Electric Field ◽  
Early Stage ◽  
Research Work ◽  
Target Surface ◽  
Electron Mass ◽  
Metal Target ◽  
Free Electron Density ◽  
Ultrashort Laser

The early-stage evolution of electrons emitted from a metal target surface during ultrashort laser ablation in vacuum has been studied using a physics-based model. This kind of research work has been rarely reported in literature. In the model, the target heat transfer process is simulated by solving the two-temperature heat transfer equations, based on which the photoemission and thermionic emission of electrons from the target surface are calculated. The early-stage evolution of emitted electrons is described by solving the electron mass, momentum, and energy conservation equations, coupled with the Poisson’s equation that governs the developed electric field. The study shows that a relatively very high free electron density can be developed near the target surface, and the front of emitted electrons propagates very fast into the vacuum. The developed electric field strongly affects the evolution of emitted electrons. Using the physics-based model, the temporal variation and the spatial distribution of the emitted electron number density, and velocity will be studied and discussed. The early-stage evolution of the emitted electrons may affect the possible subsequent hydrodynamic motion in the target, and the resulted plasma formation and material removal (laser ablation) processes. Therefore, this study provides very useful information for the understanding of ultrashort laser-material interaction, laser-induced plasma, laser ablation (machining), and other relevant processes.

Time-resolved EUV spectroscopy in the early stage of laser ablation of carbon

2002 ◽  
Vol 197-198 ◽  
pp. 164-168 ◽  
Author(s):  
Pierre Loiseleur ◽  
Tue N Hansen ◽  
Jean Larour ◽  
James G Lunney
Keyword(s):  
Laser Ablation ◽  
Early Stage ◽  
Time Resolved

scholarly journals Dynamics of picosecond laser ablation for surgical treatment of colorectal cancer

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. J. Beck ◽  
I. Bitharas ◽  
D. P. Hand ◽  
T. Maisey ◽  
A. J. Moore ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Laser Ablation ◽  
High Speed ◽  
Thermal Damage ◽  
Early Stage ◽  
Colorectal Neoplasia ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Surrounding Tissue ◽  
Picosecond Laser Pulses

AbstractEndoluminal surgery for the treatment of colorectal neoplasia is typically carried out using electrocautery tools which imply limited precision and the risk of harm through collateral thermal damage to the adjacent healthy tissue. As a potential alternative, we present the successful colonic epithelial laser ablation by means of picosecond laser pulses. Laser ablation studies performed in ex-vivo colon tissue result in cavities with comparable thickness to early stage colorectal cancers. The corresponding histology sections exhibit only minimal collateral damage to the surrounding tissue and the depth of the ablation can be controlled precisely by means of the pulse energy. High-speed imaging has been used for the first time to visualize picosecond laser ablation of cancerous tissue in a clinically relevant model. This information was correlated with histopathology and optical surface profilometry revealing the dynamic nature of the laser tissue interaction and the need for temporal or spatial separation of pulses for optimum efficacy with regards to tissue removal. Overall, the application of picosecond laser pulses to ablate endoluminal bowel lesions demonstrates significantly improved precision and reduced thermal damage to the adjacent tissue in comparison to conventional procedures and hence will enable more precise surgical treatment of cancers.

Laser plasma interaction at an early stage of laser ablation

1999 ◽  
Vol 85 (5) ◽  
pp. 2899-2903 ◽  
Author(s):  
Y. F. Lu ◽  
M. H. Hong ◽  
T. S. Low
Keyword(s):  
Laser Ablation ◽  
Laser Plasma ◽  
Early Stage ◽  
Plasma Interaction ◽  
Laser Plasma Interaction

Method for measuring wave parameters in films from electric signal detection

2011 ◽  
Vol 56 (2) ◽  
pp. 226-231
Author(s):  
I. V. Simonov ◽  
I. M. Smirnov
Keyword(s):  
Signal Detection ◽  
Electric Signal ◽  
Wave Parameters

Early stage of the material removal during ArF laser ablation of graphite

2004 ◽  
Vol 79 (3) ◽  
pp. 579-585 ◽  
Author(s):  
Z. Márton ◽  
L. Landström ◽  
P. Heszler
Keyword(s):  
Laser Ablation ◽  
Material Removal ◽  
Early Stage ◽  
Arf Laser
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