Signal processing and amplifier design for inexpensive genetic analysis instruments.

摘要

The Applied Miniaturisation Laboratory (AML) has recently built a laser-induced fluorescent capillary electrophoresis (LIF-CE) genetic analysis instrument, called the Tricorder Tool Kit (TTK). By using a photodiode instead of photomultiplier tubes in the optical detection, the AML has lowered the cost and size compared to commercial LIF-CE products. However, maintaining an adequate signal-to-noise (SNR) and limit of detection (LOD) is a challenge.;By implementing a multistage amplifier, we increased the bandwidth and voltage swing while maintaining the transimpedance gain compared to the previous design. We also developed signal processing algorithms for post-experiment processing of CE. Using wavelet transform, iterative polynomial baseline fitting, and Jansson's deconvolution, we improved the SNR, reduced baseline variations, and separated overlapping peaks in CE signals. By improving the electronics and signal processing, we lowered the LOD of the TTK, which is a step towards the realisation of inexpensive point-of-care molecular medical diagnosis instruments.