Sensitivity of higher mode of rectangular atomic force microscope to surface stiffness in air environment

Micro & nano letters

article

M. Damircheli¹  M.H. Korayem² 

[1] Department of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University;Robotic Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology

关键词: atomic force microscopy;    cantilevers;    elasticity;    surface phonons;    surface stiffness;    air environment;    resonance frequency;    flexural vibration modes;    rectangular atomic force microscopy;    rectangular cross-section cantilever;    sample stiffness;    Timoshenko beam theory;    tangential force;    vertical force;    tip position;    tip angle;    soft materials;    sample elasticity;    high-contrast images;    material stiffness;   

DOI  :  10.1049/mnl.2013.0533

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Background: Using an algorithm by which the effect-site concentration of propofol (esTEC) necessary for BIS level set from information input from BIS monitor and target controlled infusion (TCI) pump is estimated, we evaluated the accuracy of administration of propofol guided esTEC, whether it is equivalent to that guided BIS value. Methodology: The clinical data of 29 adult patients, who received head/neck surgery and 27 adult patients, who received gynecological surgery, in our hospital from February 2016 and December 2017 were analyzed. Patients were divided into 2 groups: BIS group (adjustment the propofol dose using a target BIS index of 35 to 55, head/neck surgery n = 15, gynecological surgery n = 14); and esTEC group (adjustment the propofol based on esTEC45, head/neck surgery n = 14, gynecological surgery n = 13). The relevant data from 2 groups were collected and analyzed. For statistical analysis, the unpaired t-test, chi-squared test and Wilcoxon test were used, and p < 0.05 was considered statistically significant. Results were expressed as means ± standard deviation. Results: For head and neck surgery, the percentage of time with BIS35-55 was significantly greater in the esTEC group than the BIS group (95 ± 5% and 81 ± 18%, respectively, p < 0.01), as was the percentage of time with BIS<55 (96 ± 5% and 86 ± 17%, respectively, p = 0.0274). For gynecological surgery as well, the percentage of time with BIS35-55 was significantly higher in the esTEC than the BIS group (95 ± 4% and 82 ± 13%, respectively, p < 0.01), as was the percentage of time with BIS<55 (97 ± 3% and 88 ± 15%, respectively, p = 0.0292). Conclusion: This investigation showed with surgeries at two sites and with patients of different characteristics that propofol dose adjustment based on esTEC could maintain BIS index within the target range similar to adjustment by an attending resident of anesthesia using the BIS index.

【 授权许可】

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