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1.
Med Eng Phys ; 37(4): 384-91, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25686672

RESUMO

Backward heating reduction is vital in power distribution optimization in microwave thermal ablation. In this study, we optimized dual slot antenna to yield reduction in backward heating pattern along the antenna shaft with the application of floating metallic sleeve. Finite element methods were used to generate the electromagnetic (EM) field and thermal distribution in liver tissue. The position of the sleeve from the tip of the probe (z = 0 mm) was varied within the range 14 ≤ z ≤ 22 mm while sleeve length was varied within 16 ≤ z ≤ 48 mm at 2 mm interval using operating frequency of 2.45 GHz. The best optimized design has reflection coefficient of -20.87 dB and axial ratio of 0.41 when the sleeve position was at 17 mm and sleeve length was 18 mm. Experimental validation shows that inclusion of a floating metallic sleeve on dual slot antenna for hepatic microwave ablation averagely increased ablation diameter and aspect ratio by 17.8% and 33.9% respectively and decreased ablation length by 11.2%. Reduction in backward heating and increase in power deposition into liver tissue could be achieved by using this antenna to provide greater efficiency and localization of specific absorption rate in delivering microwave energy for hepatic ablation.


Assuntos
Técnicas de Ablação/instrumentação , Técnicas de Ablação/métodos , Micro-Ondas , Equipamentos e Provisões para Radiação , Animais , Simulação por Computador , Campos Eletromagnéticos , Desenho de Equipamento , Análise de Elementos Finitos , Temperatura Alta , Fígado/efeitos da radiação , Metais , Modelos Teóricos
2.
Nig Q J Hosp Med ; 22(2): 103-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23175907

RESUMO

BACKGROUND: Electrolytes and acid-base disorders are common challenges seen in the intensive care unit (ICU) resulting in difficulty in weaning patients off the ventilator, prolonged admission periods, preventable cardiac arrhythmias and cardiac arrest. These require prompt lab results most of which are done serially, ideally a point of care test (POCT), as most central hospital lab result's turnaround time (TAT) sometimes might not meet up with the urgency of clinical decision making in the ICU. OBJECTIVE: To determine the incidence of electrolytes and acid-base abnormalities using i-Stat portable analysers in the ICU of the Lagos University Teaching Hospital (LUTH). METHOD: The i-STAT Portable Clinical Analyzer, a POCT system consisting of a hand-held analyzer and single-use cartridges that measure different panels of analytes in 65-100 microl of blood using an EC8+ cartridge type analyzer for sodium, potassium, chloride, urea, glucose, pH, blood gases [TCO2, pO2, pCO2]) and heamatocrit was used. RESULTS: Over 66.78% of the patients had multiple electrolytes and acid-base abnormalities. Azotemia in 20%, hypoglycaemia in 13.33%, and hyperglycaemia in 53.33% of patients. CONCLUSION: it is concluded from this study that electrolyte and acid base abnormalities is not uncommon in the intensive care unit of LUTH and the i-STAT Portable Clinical Analyzer was helpful in facilitating early diagnosis and treatment.


Assuntos
Desequilíbrio Ácido-Base/sangue , Desequilíbrio Ácido-Base/diagnóstico , Estado Terminal , Sistemas Automatizados de Assistência Junto ao Leito , Equilíbrio Hidroeletrolítico , Desequilíbrio Hidroeletrolítico/diagnóstico , Adulto , Feminino , Hospitais de Ensino , Humanos , Incidência , Masculino , Monitorização Fisiológica/instrumentação , Desequilíbrio Hidroeletrolítico/sangue
3.
East Afr Med J ; 89(10): 339-44, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26852444

RESUMO

BACKGROUND: Intra-operative death is an unusual devastating occurrence in anaesthetic practice, and it is of serious concern when it happens. OBJECTIVES: To assess the causes, the effects and the perception of Nigerian anaesthetists to intra-operative death. DESIGN: A cross-sectional and questionnaire-based study. SETTING: Five University Teaching Hospitals in South-Western Nigeria. SUBJECTS: Nurse anaesthetists, resident doctors in anaesthesia and consultant anaesthetists. RESULTS: One hundred and five anaesthetists participated in the study (72.9% response rate). Seventy seven (73.3%) of the respondents had experienced an intra-operative death with most of them having five or more years of experience (p = 0.0001). Majority 53 (68.8%) of the respondents felt that the deaths were avoidable, and most deaths occurred mainly during emergency surgery (96.1%). Forty three (55.8%) of them were psychologically disturbed, fifty six (53.3%) respondents were of the opinion that it is reasonable for the anaesthetists involved not to take partin further surgery for that day. Sixty (57.1%) respondents considered discussion at mortality meeting as appropriate after an intra-operative death. CONCLUSION: This study showed that most anaesthetists would want those involved in the intra-operative death not to take part in further surgery for that day. Adequate preventive measures should be put in place with departmental or institutional policies on what to do after such events.


Assuntos
Anestesiologia , Atitude do Pessoal de Saúde , Atitude Frente a Morte , Morte Súbita , Emergências/psicologia , Cuidados Intraoperatórios/psicologia , Percepção Social , Adulto , Estudos Transversais , Morte Súbita/prevenção & controle , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Hospitais Universitários , Humanos , Complicações Intraoperatórias/psicologia , Masculino , Nigéria , Inquéritos e Questionários , Recursos Humanos
4.
Nig Q J Hosp Med ; 21(2): 119-23, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21913508

RESUMO

BACKGROUND: In Nigeria, manual methods of heartbeat monitoring are commonly used which are subject to a number of human errors and problems. OBJECTIVE: This paper describes the development of a noninvasive EPROM based heartbeat monitor using optical biomedical engineering technique to detect and count the user's heartbeat digitally as well as provide a visual indication of the result obtained. METHODS: This design and construction work employed the optical biomedical engineering technique in which tiny subcutaneous blood vessels in any patch of skin preferably the fingers furnished with a good supply of blood alternately expand and contract in time with the heartbeat. The optical sensors were planted in a peg which provides firm grip of the finger tip to sense these contraction and expansion processes. RESULTS: The results of the tests carried out on fingers of different individuals at rest showed that the thumb, middle finger and forefinger responded more accurately to the heartbeat measurements taken. The thickness of the individual's fingers contributed greatly to the accuracy of the measurement taken. CONCLUSION: The EPROM based heartbeat monitor is a very efficient tool for monitoring the heartbeat of patients. However, its efficiency is determined by the thickness of the individual's finger.


Assuntos
Testes de Função Cardíaca/métodos , Frequência Cardíaca , Monitorização Fisiológica/instrumentação , Engenharia Biomédica/instrumentação , Desenho de Equipamento , Humanos , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador/instrumentação
5.
Niger J Clin Pract ; 14(1): 98-101, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21494002

RESUMO

The submental / transmylohyoid intubation technique, as an alternative technique of airway management in oral and maxillofacial surgery, and its modifications, have been widely reported in the literature since it was first described by Altemir in 1986. However, the technique is not yet popular in Nigeria and Africa in general. A report of two cases in which this technique was used in orofacial reconstruction is presented here. The surgical / anesthetic outcome was satisfactory. No complication was seen in the two cases, and healing of the submental wound was uneventful. Submental intubation is a reliable technique of alternative airway management in oral and maxillofacial surgery. The submental / transmylohyoid technique should be considered by both the anesthetist and the maxillofacial surgeon in challenging cases, where an alternative airway technique is required for maxillofacial surgery.


Assuntos
Intubação Intratraqueal/métodos , Traumatismos Maxilofaciais/cirurgia , Cirurgia Bucal/métodos , Manuseio das Vias Aéreas , Criança , Humanos , Intubação Intratraqueal/instrumentação , Masculino , Noma/cirurgia , Fístula Bucal/cirurgia , Procedimentos Cirúrgicos Ortognáticos , Procedimentos Cirúrgicos Reconstrutivos , Resultado do Tratamento , Adulto Jovem
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