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Showing posts from April, 2021

Fundamentals and Design of Pulse Oximeter

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Background The human body is composed of trillions of cells, each of which requires the continuous supply of oxygen (O_2) and the excretion of carbon dioxide (CO_2) for metabolism and survival. Therefore, measuring the amount of oxygen present in blood or tissues could help assess a person’s health and overall well-being [1]. Blood oxygenation is the measure of oxygen present in arterial or venous blood, while the measure of oxygen present in the vascular tissue or microvascular bed is referred to as tissue oxygenation. Blood oxygenation assesses how well oxygen binds to hemoglobin, indicating the adequacy of pulmonary gas exchange. Tissue oxygenation indicates the adequacy of tissue perfusion and is primarily determined by the local delivery of oxygenated blood [2] Oxygen enters the lungs and then passed into the blood. The blood carries oxygen to the various organs in our body. The main way oxygen is carried in our blood is through hemoglobin. The hemoglobin without oxygen is called ...

High Speed Digital Design Considerations

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The four main consideration of today’s high-speed design:                                                                                                                                                            Ref(1) We need to consider signal integrity , which includes parameters such as Overshoot and Ringing. Need to look at crosstalk which is about EMI coupling between traces on PCB board Timing is about calculating the flight time EMI and radiation  These parameters are related to each other and aff...