Two-dimensional potential, electric field and drain current model of source pocket hetero gate dielectric triple work function tunnel field-effect transistor

Micro & nano letters

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Dheeraj Sharma¹  Bhagwan Ram Raad¹  Dharmendra Singh Yadav¹  Pravin Kondekar¹  Kaushal Nigam¹ 

[1] Electronics and Communication Engineering Discipline, Indian Institute of Information Technology

关键词: electric fields;    semiconductor device models;    tunnel transistors;    field effect transistors;    high-k dielectric thin films;    Poisson equation;    work function;    two-dimensional potential;    drain current model;    source pocket hetero gate dielectric triple work function tunnel field-effect transistor;    negative gate-to-source voltage;    steep subthreshold slope tunnel field-effect transistor;    low work function;    gate contact;    high-κ gate dielectric;    gate electrode;    tri metal hetero gate dielectric delta doped TFET;    two-dimensional Poisson equation;    2D Poisson equation;    electric field extraction;    Kane band-to-band tunnelling generation rate;    2D technology computer aided design ATLAS simulation;    electric field;   

DOI  :  10.1049/mnl.2016.0351

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

It may be unheard that a conscious patient with a tracheostomy tube in situ presents for anesthesia and poses a serious threat with his airway management. We describe a case scenario in which the tracheostomy tube could not be used to ventilate the patient, nor could it be removed. A 65 year old man was scheduled for tracheostomy tube change. He had a permanent tracheostomy (Shiley®, reusable inner cannula, cuffless fenestrated 7.6 mm internal diameter tube, Covidien Healthcare, USA) in situ. He had developed bilateral vocal cord palsy due to prolonged intubation following coronary artery bypass graft surgery (CABG) six years back. He had had two unsuccessful laser cordotomies for the vocal cord palsy. Patient had also undergone a microlaryngoscopy and biopsy of an anterior laryngeal polyp. He was a controlled diabetic and hypertensive with moderate exercise tolerance. There were no known allergies. He slept using four pillows under as he got panic attacks lying flat. He was an ex-smoker. Body mass index was 35 kg/m2. Neck movements were not restricted. At rest, his oxygen saturation was 94% on air. Chest was clear on auscultation. After routine removal of inner tube for cleaning, he was unable to replace it. He attempted repeated nebulisation without success. Spontaneous ventilation was not affected. Fibreoptic endoscopy by the surgeon under topical anesthesia showed granulation tissue trapped through the fenestration and obstructing about 50% of the outer tracheostomy tube. After a trial of removal of the granulation tissue using a tracheostomy brush failed, an attempt under general anesthesia was planned. With the patient sitting up, preoxygenation was done using a Rendell Baker Soucek mask over the outer tracheostomy tube stoma. Anesthesia was induced using 8% Sevoflurane in 100% oxygen after intravenous administration of 50 microgram fentanyl and 0.5 mg of midazolam. Anesthesia was maintained with a target controlled infusion of propofol under spontaneous ventilation. During manipulation by the surgeon, oxygen was insufflated through a small bore suction catheter in the trachea. The outer tracheostomy tube was removed using gentle traction and replaced with a size 8 Silver Negus tracheostomy tube (Kapitex Healthcare, UK). The hemodynamic parameters remained stable throughout the procedure and further clinical course was uneventful. Options for controlled ventilation in similar situation in an emergency include the use of pediatric mask, laryngeal mask airway and mouth to stoma ventilation.

【 授权许可】

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