Browsing by Author "Wijekoon, D."

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    Design and construction of low cost petri dish incubator
    (Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Wanigasekara, G.; Perera, N.W.; Abeysinghe, D.; Geegamage, S.S.; Wijekoon, D.; Jayathilaka, N.
    Petri dish incubators are used in laboratories to keep petri dish samples at a stable and optimal temperature of 37 °C. Incubators are one of the frequently needed equipment. These incubators are expensive due to the use of complex systems. Many of the local universities do not have the necessary financial resources to purchase this equipment. Therefore, undergraduate students usually do not have access to incubators for academic learning. In order to surmount this challenge, it is necessary to look at a low cost, simple design for petri dish incubators. Hence, we have designed an incubator utilizing low cost microcontroller boards and sensors. Both microcontrollers and sensors were selected to provide adequate accuracy for the incubation at 37 °C. The incubator is constructed of three major components; sensors, controller and temperature regulation system. The incubator uses three LM35 temperature sensors to monitor the temperature with 0.5 °C accuracy and the system is controlled by Arduino Uno board with 16 MHz ATmega328P microcontroller. The microcontroller regulates the temperature of the incubation chamber utilizing 200W Nichrome heating element and two exhaust fans. Three temperature sensor readings were taken to acquire chamber temperature by averaging three values. Microcontroller uses these data to control the heating element, the fan for heating and the fan for cooling. The controller uses a PID (Proportional–Integral–Derivative) algorithm to stabilize the temperature. The sensor input wiring is highly shielded to avoid interference from the main powerline magnetic noise. The incubator body is shielded with porcelain to avoid fire hazards. The average temperature recorded by the incubator sensor and the chamber temperature as recorded with a thermometer was monitored at 2 hr intervals over a 16 hr period at 37.6 ± 0.5 °C and 37.6 ± 0.5 °C respectively indicating the accuracy of temperature regulation in the petri dish incubator over an extended period of incubation.
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    Post-placental and interval intrauterine contraceptive device (IUD) insertion: does timing matter?
    (Wiley-Blackwell, 2015) Dias, T.D.; Palihawadana, T.S.; Wijekoon, D.; Ganeshamoorthy, P.; Abeykoon, S.; Liyanage, G.; Padeniya, T.
    INTRODUCTION Unintended pregnancies in the first year after childbirth could be high as 10–44% and expose women to consequences of induced abortion, especially in countries where termination of pregnancy is illegal. Immediate postpartum contraception methods are beneficial for women who wish for early contraception and for women who have difficulty in returning for postpartum visits for contraception. Use of Copper containing intrauterine contraceptive device (IUD) immediately after delivery (post placental) has been described recently with varying success. The aim of this study was to compare the rate of spontaneous expulsion and intrauterine displacement between post placental IUD insertion and routine IUD insertion, 6 weeks after delivery. METHODS This was an interventional comparative study. Women who were willing to start on IUD as a contraceptive method after childbirth were recruited for the study. They were randomly allocated to either group before labour/ delivery and those in the group of post placental insertion had it inserted immediately following vaginal delivery and those allocated for interval group had insertion 6 weeks after delivery. Two ultrasound examinations were performed, just after the insertion and 6 weeks later in both groups. The distance from the IUD to the internal os was measured at each examination to evaluate the displacement. RESULTS The study included 30 subjects in the post placental group and 33 in interval insertion group. The postpartum insertion group and the interval insertion groups were comparable for age [mean (SD) 27.1 (5.42) versus 25.6 (4.34), P = 0.23] and BMI [mean (SD) 22.4 (7.28) versus 23.9 (5.76), P = 0.34]. As expected, the uterine length at insertion was higher among the post placental group [mean (SD) 144.1 mm (12.2) versus 66.8 (6.7), 95%CI 72.3 to 82.1] but similar in two groups at follow up [66.6 mm (15.1) versus 64.79 (6.64), 95%CI _4.01 to 7.47]. Spontaneous expulsion and displacement was not significantly different between the post placental and interval insertion groups [3/30 versus 2/33, OR 1.72; 95%CI 0.28 to 10.7]. In these two groups, there was no difference noted in the second ultrasound measurements from the IUD to the fundal wall [16.9 mm (3.99) versus 18.24 (4.36); 95%CI _3.45 to 0.77] or to the internal os [21.8 mm (15.7) versus 17.1 (6.03); 95%CI _1.12 to 10.6]. CONCLUSION This study demonstrates that insertion of an IUD immediately after delivery does not increase the risk of spontaneous expulsion or the risk of downward displacement. Therefore, such insertion can be recommended in clinical practice