Temperature measurement has many applications in medical devices. In recent days, body temperature become the main screening procedure to justify people infected by SARS-CoV-2. Related to pandemic situation due to SARS-Cov-2, Polymerase Chain Reaction (PCR) method become the most accurate and reliable detection method. This method employs a device named PCR machine or Thermal Cycler. In this research, we focus to build a Thermal Cycler using a low-cost material such as aluminium and using a liquid coolant as the cooling system. We use 2 types of coolant solution: mineral water and generic liquid coolant. Peltier device in thermal cycler serves as heating and cooling element. In heating rate experiments, generic liquid coolant shows a better result than using mineral water due to specific heat capacity and thermal conductivity of water. In the cooling rate experiments, the water pump is activated to stream the liquid solution, the flow rate of liquid solution is influenced by viscosity of the liquid. Generic liquid coolant has approx. 4,5 times greater viscosity than water. The higher flow rate means better performance for cooling rate. Using 2 pieces of 60-Watt heaters and a 60-Watt chiller and aluminium material as block sample, our research shows a heating and cooling rate up to approx. 0,1°C/s. Compared to commercially thermal cycler, our thermal cycler has a lower wattage; this lower wattage performance has been tradeoff with lower ramping rate. Some factors are suspected become the source of contributors of lower ramping rate.

Pada masa pandemi Covid-19, teknik penggandaan DNA dengan metode Polymerase Chain Reaction (PCR) menjadi gold standard untuk diagnosis virus dan penghitungan sampel klinis. Metode PCR ini diimplementasikan pada alat dengan nama Thermal Cycler atau mesin PCR. Salah satu komponen utama dalam Thermal Cycler adalah pemanas. Tiga buah pemanas, yakni: Peltier Device 12715, Ceramic Heater PTC 12 VDC, dan Customized Heater 12 VDC diuji kinerjanya dengan dihubungkan pada blok aluminium. Dua buah Ceramic Heater PTC 12 VDC dengan daya total sebesar 120 W menunjukkan kinerja terbaik dibandingkan 2 pemanas lainnya dan mampu memberikan laju pemanasan sebesar 0,13 ℃/detik.

A collimator simulator which is an accessory in radiology equipment, has been made. This simulator was created as a learning medium to complete students' understanding in studying x-rays as part of electromagnetic waves. The research is divided into two stages, namely the manufacture of simulators and implementation as teaching materials. The collimator simulator is equipped with blades that are used to limit the radiation field area. In this study, collimator lamps were used to see the area of the field. The simulator is equipped with a motor to open and close the radiation window. The results of the implementation to students stated that students agreed that the collimator simulator learning media helped students to better understand the material. Keywords: learning media, collimator, radiation field area

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The aim of this study is to determine the effect of room's light condition to brain response. Brain response to repetitive visual stimulation is called Steady-State Visual Evoked Potential (SSVEP) based Brain-Computer Interface (BCI). In this study, flickering Light Emitting Diode (LED) is used as visual stimulation. Mostly, brain response is recorded using electroencephalograph (EEG) and recorded in the brain's occipital lobe that is associated with human vision. Welch's method of power spectral estimation is implemented for estimating the power spectral of recorded signal. The result shows that the highest-power of brain response to repetitive visual stimulus can be detected either in the dark-room or in the brightroom.