Implementation of a digital Lock-in amplifier in SoC-FPGA for Biomedical Tomography
Magnetic Tomography is a technique that uses coil arrangements to determine the conductivity and permeability profile of an object. This is achieved by applying sinusoidal stimuli to a driving coil and measuring the generated signal in a sensing coil. These signals are usually of very low amplitude...
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| Autores principales: | , , , |
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| Formato: | Objeto de conferencia |
| Lenguaje: | Inglés |
| Publicado: |
2022
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/160855 |
| Aporte de: |
| Sumario: | Magnetic Tomography is a technique that uses coil arrangements to determine the conductivity and permeability profile of an object. This is achieved by applying sinusoidal stimuli to a driving coil and measuring the generated signal in a sensing coil. These signals are usually of very low amplitude and poor levels of signal to noise ratio, but the applied stimulus is known, which enables the use of techniques such as the Lock-in amplifier to recover the response. However, the high price of commercially available devices is restrictive, so it is of interest to generate an open design. Heterogeneous embedded systems, which combine an array of programmable logic cells, a processor, peripherals, and shared memory controllers are an interesting tool to implement such a system. In this work the theoretical aspects of the Lock-in amplifier are discussed, showing that its action reduces the noise of the signals in a factor proportional to the bandwidth of the low-pass filter. Then, the design of an open-source Lock-in amplifier with a moving average filter on a DE1-SoC platform is presented, and it is experimentally shown that it reduces the noise of the signals by a factor √(N/2), where N is the number of samples involved in the calculation of the moving average. |
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