A comprehensive simulation model for the infant-incubator-feedback system was developed in a Matlab/Simulink® environment to investigate all heat exchange relationships, variables and factors that have an influence on the overall thermo-neutrality of the environment. The model was also used to determine the benefits and limitations of using a convectively heated single-walled incubator in nursing preterm infants with very low birth weight < 1000 grams and low gestational age 28 weeks. The infant was modelled as one-lump with two layers; core and skin. The infant shape was approximated to a cylinder. The model incorporated all compartments of the infant-incubator system including core, skin, incubator air space, mattress, incubator walls, air-circulating fan, heating element, added oxygen (for resuscitation purposes), and humidification chamber, which has not previously been considered. The results of the simulation were in terms of the temperature variation over time, of the following parts of the system: core and skin temperatures and incubator air space temperature. Results of the simulation with added humidity showed that the body temperature of a 900 gram infant, with an initial body temperature of 35.5 ºC, did not reach the thermo-neutral range between 36.5-37.5 ºC in two hours, on air mode. Whereas, on skin mode, both core and skin temperature reached to 36.87 ºC and 36.5 ºC in two hours, and thus a thermo-neutral environment was achieved. These outcomes are consistent with clinical empirical reports. The simulation model is a closed-loop system with a PID controller for each mode; air servo controlled and skin servo controlled. The controller parameters were virtually estimated by the Zeigler-Nichols Method as real values were not available. Nevertheless, the overall stability of the whole system has been achieved by applying a step input which was verified by the Root Locus Method.

A comprehensive simulation model for the infant-incubator-feedback system was developed in a Matlab/Simulink® environment to investigate all heat exchange relationships, variables and factors that have an influence on the overall thermo-neutrality of the environment. The model was also used to determine the benefits and limitations of using a convectively heated single-walled incubator in nursing preterm infants with very low birth weight < 1000 grams and low gestational age 28 weeks. The infant was modelled as one-lump with two layers; core and skin. The infant shape was approximated to a cylinder. The model incorporated all compartments of the infant-incubator system including core, skin, incubator air space, mattress, incubator walls, air-circulating fan, heating element, added oxygen (for resuscitation purposes), and humidification chamber, which has not previously been considered. The results of the simulation were in terms of the temperature variation over time, of the following parts of the system: core and skin temperatures and incubator air space temperature. Results of the simulation with added humidity showed that the body temperature of a 900 gram infant, with an initial body temperature of 35.5 ºC, did not reach the thermo-neutral range between 36.5-37.5 ºC in two hours, on air mode. Whereas, on skin mode, both core and skin temperature reached to 36.87 ºC and 36.5 ºC in two hours, and thus a thermo-neutral environment was achieved. These outcomes are consistent with clinical empirical reports. The simulation model is a closed-loop system with a PID controller for each mode; air servo controlled and skin servo controlled. The controller parameters were virtually estimated by the Zeigler-Nichols Method as real values were not available. Nevertheless, the overall stability of the whole system has been achieved by applying a step input which was verified by the Root Locus Method.

The topic of this master’s thesis is design of infant incubator. The thesis concerns own design of infant incubator that meet the basic technical, ergonomical and social requirements and also brings a new look and shape as solution to the main topic. The infant incubator is designed in regard to modern materials and technologies.

Submitted by infopei ufba (infopei@ufba.br) on 2017-05-10T19:11:06Z No. of bitstreams: 1 TeseJosemirAlexandrino.pdf: 4030416 bytes, checksum: 971f2eadd7c4d23fb1945b3a4dfbd1d5 (MD5) / Approved for entry into archive by Flávia Sousa (flaviabs@ufba.br) on 2017-05-29T19:00:57Z (GMT) No. of bitstreams: 1 TeseJosemirAlexandrino.pdf: 4030416 bytes, checksum: 971f2eadd7c4d23fb1945b3a4dfbd1d5 (MD5) / Made available in DSpace on 2017-05-29T19:00:57Z (GMT). No. of bitstreams: 1 TeseJosemirAlexandrino.pdf: 4030416 bytes, checksum: 971f2eadd7c4d23fb1945b3a4dfbd1d5 (MD5) / MS, CNPq, FAPESB, SESAB, SECTI e IFBA / O uso massivo de tecnologia na área da saúde tem elevado a efetividade dos procedimentos médicos, com consequente melhoria da qualidade de vida dos pacientes. Entretanto, tais tecnologias trazem riscos intrínsecos, que podem resultar em danos, quando mal utilizadas ou mantidas. Neste contexto, encontram-se os Equipamentos Médico-hospitalares (EMH) que podem apresentar problemas que resultem em diagnósticos errôneos, terapias inapropriadas ou que comprometam a segurança dos usuários. A avaliação periódica, e em particular, do desempenho metrológico, constitui-se em importante meio para alcançar o uso seguro do EMH. As soluções encontradas para tal avaliação são rigidamente condicionadas às especificidades de cada tipo de EMH e dificilmente podem ser aproveitadas para outros. Embora não tenha sido encontrada na literatura uma solução generalista que possa ser aplicada a determinados tipos de EMH, esta indica viabilidade de aplicação, em função dos constantes avanços tecnológicos do setor. Neste sentido, este trabalho apresenta uma metodologia para a avaliação do desempenho metrológico de EMHs e para tal, foi desenvolvido um sistema que reúne instrumentos de medição integrados a um software gerenciador de ensaios. Este software realiza a aquisição e monitoramento de dados de medição relativos às variáveis metrológicas do equipamento sob teste, avalia a adequação destes dados a requisitos metrológicos preestabelecidos e emite relatório de conformidade. O sistema permite a configuração de diversos parâmetros, possibilitando a execução de avaliações de desempenho metrológico em diferentes tipos de EMH. Para fins de validação, o sistema foi configurado para realizar avaliações em bisturis elétricos e incubadoras neonatais. Os resultados mostram a eficácia da metodologia desenvolvida e a eficiência da plataforma computacional para avaliação metrológica de EHM. / The massive use of technology in health care has increased the effectiveness of medical procedures, with consequent improvement of quality of life of patients. However, such technologies carry inherent risks that can result in damage when misused or maintained. In this context, are the medical and hospital equipment (MHE) that can present problems that result in misdiagnosis, inappropriate therapies or which compromise the safety of users. The periodic assessment, especially of the metrological performance constitutes an important means to achieve the MHE safe use. The solutions for such evaluation are tightly constrained to the specific characteristics of each type of MHE and can hardly be reutilized for others. Although not found in the literature a general solution that can be applied to certain types of MHE, this indicates the feasibility of application, in function of the constant technological advances in the medical equipment industry. Thus, this work presents a methodology for evaluating the metrological performance of MHE and for such, a system was developed that brings together measuring instruments integrated into software for testing manager. This software performs the acquisition and monitoring of measurement data related to the metrological variables of equipment under test, assesses the adequacy of these data to preestablished metrological requirements and issues a compliance report. The system allows configuration of various parameters, enabling the execution of metrological performance evaluations in different types of MHE. For verification purposes, the system was configured to perform evaluations of high frequency electrosurgical scalpels and neonatal incubators. The results show the effectiveness of the developed methodology and the efficiency of the computational platform for metrological evaluation of MHE.