Signal processing and amplifier design for inexpensive genetic analysis instruments

• Author / Creator

  Choi, Sheng Heng

• 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.

• Subjects / Keywords

  • Capillary electrophoresis
  • Peak detection
  • Overlapping peak separation
  • Signal processing
  • Jansson's deconvolution
  • Wavelet transform
  • Multistage amplifier

• Graduation date

  Fall 2011

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3Z33Q

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.