ENCIT2012-121 A COMPARTMENT MODEL TO EVALUATE THE HEAT TRANSFER IN THE HUMAN RESPIRATORY TRACT - PDF
Cyro Albuquerque, FEI, Brazil
Jurandir Itizo Yanagihara, USP, Brazil
Abstract: A mathematical model is proposed to determine the heat transfer in the respiratory tract, taking into account the tissue temperature. The respiratory tract is divided into compartments representing the inspiration path, the expiration path and the alveolar space. Flows of dry air and water vapor take place between the compartments and with the environment. The compartments exchange heat and water vapor with the tissues. Mass and energy balances allow the calculation of their temperature and humidity. Results of the model are similar to the results from the classical methodology, but has the improvement of considering the tissue temperatures, besides the environmental conditions and the pulmonary ventilation.
Keywords:bioheat transfer; respiratory tract; thermoregulation.
Presentation Schedule: Wednesday, 10:20-10:40. Session: BIO-1. Presenter: Cyro Albuquerque.
ENCIT2012-051 DEVELOPMENT AND VALIDATION OF PHYSIOLOGICAL PHARMACOKINETIC MODEL USING LINEAR SYSTEM ANALYSIS FOR THE PREDICTION OF MEDICAMENTS DISTRIBUTION IN THE HUMAN BODY. - PDF
Milton Gallo Neto, Maurício Silva Ferreira, Jurandir Itizo Yanagihara, USP, Brazil
Abstract: Pharmokinetic models are important tools to predict drug distribuition in the human body. In the present study, the development of a physiological pharmacokinetic model is reported. This model uses physiological parameters from experimental researches. To obtain numerically the values of drug concentration for blood, organs and tissues, linear system analisys was utilized.
Keywords:Pharmacokinetic model; linear system; biomedical engineering.
Presentation Schedule: Thursday, 10:20-10:40. Session: BIO-2. Presenter: Milton Gallo-Neto.
ENCIT2012-226 IN-VITRO STUDY OF FILTERING EFFICIENCY IN VENA CAVA FILTERS - PDF
Marcelo Peixer Corbellini, Amir Antônio Martins de Oliveira Júnior, UFSC, Brazil
Fernando Marcelo Pereira, UFRGS, Brazil
Abstract: Inferior vena cava filters are used in order to avoid pulmonary embolism. Three commercial vena cava filters were evaluated for their clot trapping efficiency and pressure loss due to insertion of blood clots. An in vitro flow circulation system was built with a simulated inferior vena cava. Blood thrombi were made from fresh bovine blood and cut into different lengths. Blood clots were inserted in the system and the clot trapping efficiency was measured by computing the clots trapped by the filters. Pressure loss was measured with an open manometer as clots were inserted in the system. Results indicate a notable increase in efficiency as longer clots are used in the experiments. For a larger number of blood clots (>30) a strong decrease in filter efficiency is observed. There was no difference in the pressure loss measured for the first ten clots among the filters tested and a higher pressure was measured for larger number of captured thrombi. In conclusion, we have found no significant difference in the clot trapping efficiency among the filters but different values for the pressure loss and clot trapping efficiency for larger numbers of captured thrombi.
Keywords:pulmonary embolism; inferior vena cava filters; clot trapping efficiency; pressure loss.
Presentation Schedule: Thursday, 09:00-09:20. Session: BIO-2. Presenter: Marcelo Peixer Corbellini.
ENCIT2012-081 EXERGY ANALYSIS OF HUMAN BODY UNDER DIFFERENT ENVIRONMENTAL CONDITIONS - PDF
Carlos Eduardo Keutenedjian Mady, Maurício Silva Ferreira, Jurandir Itizo Yanagihara, Paulo Hilário Saldiva, Silvio de Oliveira Junior, USP, Brazil
Abstract: Exergy analysis was applied to assess the energy conversion processes that take place in the human body aiming to obtain indicators of thermal confort conditions, from correlations of the destroyed exergy and exergy efficiency with environmental parameters. The human thermal model used to perform the exergy analysis is composed of 15 cylinders with elliptical cross section (which leads to realistic dimensions) representing: head, neck, trunk, arms, forearms, hands, thighs, legs, and feet. For each cylinder a combination of the following tissues was considered: skin, fat, muscle, bone, brain, viscera, lung, and heart. The exergy analysis was applied for each element, being possible to obtain exergy rates and flow rates associated with radiation, convection, vaporization and respiration. Besides, it was possible to determine a transitory response of the body over time. Results indicate that the body destroys less exergy and is more efficienct for higher operative temperatures. Moreover, a combination of low air temperature and high mean radiant temperature leads to a higher exergy efficiency and a lower destroyed exergy.
Keywords:Exergy analysis; Exergy efficiency; human body behavior.
Presentation Schedule: Wednesday, 10:00-10:20. Session: BIO-1. Presenter: Carlos Eduardo Keutenedjian Mady.
ENCIT2012-109 THE ADVANCEMENT OF THERMAL SCIENCE AND ITS CONTRIBUITION TO MEDICINE: MATHEMATICAL METHOD PROPOSED FOR THE INTERPRETATION OF INFRARED - PDF
Marcos Leal Brioschi, Keli Cristiane Correia Morais, Stella Holzbach Oliari, José Viriato Coelho Vargas, UFPR, Brazil
Abstract: This paper presents such as thermography, a noninvasive method, has aided in the diagnosis of tumors in symmetrical regions of the body. The objective of this work is to standardize a technique to diagnose tumors in symmetrical regions of the human body using the conjugate gradient method proposed by Vargas (2010). The use of a standard methodology for the analysis of infrared imaging seeks to eliminate the dependence of the temperature data and the patient's body at the time of measurement.
Keywords:thermometry; infrared imaging; breast cancer; temperature.
Presentation Schedule: Thursday, 09:40-10:00. Session: BIO-2. Presenter: Keli Cristiane Correia Morais.
ENCIT2012-056 CEREBROSPINAL FLUID DRAINAGE DEVICES: EXPERIMENTAL CARACTERIZATION - PDF
Camila Bim, Sérgio Said Mansur, Edson Del Rio Vieira, UNESP, Brazil
Marcos Pinotti, UFMG, Brazil
José Ricardo Camilo, Angelo L. Maset, Ventura Biomédica, Brazil
Abstract: The hydrocephalus is a pathophisiology that due to the excess of cerebrospinal fluid in brain ventricles, and it can be caused by birth defects, brain abnormalities, tumors, inflammations, infections, intracranial hemorrhage and others. Hydrocephalus can be followed by significant rise of intracerebral pressure due to the excess of production of cerebrospinal fluid over the absorption, resulting in a weakening of intellectual functions, serious neurological damage (decreased movement, sensation and functions), critical physical disabilities and even death. A procedure for treatment involves the placement of a ventricular catheter into the cerebral ventricles to divert/drain the cerebrospinal fluid flow to a bag outside of the body - provisory treatment known as external ventricular drainage (EVD). Another option is the permanent treatment, internal ventricular drainage (IVD), that promote the cerebrospinal fluid drainage to other body cavity, being more commonly the abdominal cavity. In both cases, EVD and IVD, it is necessary to use of several types of neurological valves in order to control the flow of cerebrospinal fluid. So in the present work proposes the experimental hydrodynamic study about one way membrane neurological valve, to verify their behavior when subjected to various pressure gradients found in the human body. The results showing a hydrodynamic feature specific.
Keywords:Hydrocephalus; Cerebrospinal fluid; Ventricular drainage.
Presentation Schedule: Wednesday, 09:40-10:00. Session: BIO-1. Presenter: Camila Bim.
ENCIT2012-162 IN VITRO EVALUATION OF THE HEAT TRANSFER IN ENDOVENOUS LASER TREATMENTS - PDF
André Amâncio de Moraes, Marcelo Peixer Corbellini, Amir Antônio Martins de Oliveira Júnior, UFSC, Brazil
Wagner P. Ferreira, CTV - Ribeirão Preto, Brazil
Fernando M. Pereira, UFRGS, Brazil
Abstract: The endovenous laser treatment (EVLT) of varicose veins has been widely adopted based on its good results, but its mechanism of action is yet barely known. In this work an experimental study of the heat transfer within the vein during an endovenous laser treatment is conducted using a silicone vein model (in horizontal position) filled with bovine blood. The results showed that the heat transfer is not homogeneous along the vein perimeter and that the bubble formation may play a central role in the energy distribution within the vein. The heat flux to the upper part of the vessel wall may be more than 15 times higher than the heat flux to the bottom part. This non homogeneity of the heat flux may help in explaining the recanalization problems still found in some patients submitted to the endovenous laser treatment.
Keywords:endovenous laser treatment; temperature measurement; heat flux non homogeneity; recanalization.
Presentation Schedule: Thursday, 09:20-09:40. Session: BIO-2. Presenter: Fernando M. Pereira.
ENCIT2012-396 NEAR INFRARED LIGHT HEATING OF PHANTOM LIKE SOFT TISSUES CONTAINING NANOPARTICLES - PDF
Simon Eibner, École des Mines d'Albi, France
Rodrigo Alfredo Oliveira Jaime, Bernard Lamien, Rodrigo Basto, Helcio Rangel Barreto Orlande, UFRJ, Brazil
Olivier Fudym, École des Mines d'Albi, France
Abstract: The objective of this paper is to investigate the effect of the addition of nanoparticles in a phantom like soft tissue, which is useful in photothermal therapy for cancer or tumor treatment. Polyvinyl chloride-plastisol (PVC-P) is used as phantom for such a purpose. The Optical characterization shows respectively that the obtained absorption coefficient is relatively closed to the absorption coefficient of human fat, while the thermophysical characterization shows that the measured thermal properties are different from selected human soft tissues thermophysical properties reported in literature. Two types of nanoparticles are used as photothermal agents, as well as, a thermal paste. The PVC-P phantom is transparent to the near infrared laser light, whereas the addition of titanium dioxide nanoparticles enhanced the optical properties resulting in a local heat source.
Keywords:Hyperthermia; NIR Laser; Photothermal Therapy; Phantom; - Photoabsorbing Nanoparticles.
Presentation Schedule: Thursday, 10:00-10:20. Session: BIO-2. Presenter: Helcio Rangel Barreto Orlande.