Title :
Analog CMOS Design for Optical Coherence Tomography Signal Detection and Processing
Author :
Xu, Wei ; Mathine, David L. ; Barton, Jennifer K.
Author_Institution :
Univ. of Arizona, Tucson
Abstract :
A CMOS circuit was designed and fabricated for optical coherence tomography (OCT) signal detection and processing. The circuit includes a photoreceiver, differential gain stage and lock-in amplifier based demodulator. The photoreceiver consists of a CMOS photodetector and low noise differential transimpedance amplifier which converts the optical interference signal into a voltage. The differential gain stage further amplifies the signal. The in-phase and quadrature channels of the lock-in amplifier each include an analog mixer and switched-capacitor low-pass filter with an external mixer reference signal. The interferogram envelope and phase can be extracted with this configuration, enabling Doppler OCT measurements. A sensitivity of -80 dB is achieved with faithful reproduction of the interferometric signal envelope. A sample image of finger tip is presented.
Keywords :
CMOS analogue integrated circuits; Doppler measurement; biomedical electronics; biomedical measurement; biomedical optical imaging; demodulators; integrated circuit design; light interferometry; low-pass filters; medical image processing; optical tomography; photodetectors; switched capacitor filters; Doppler OCT measurement; analog CMOS circuit design; analog mixer; biomedical imaging; differential gain stage; external mixer reference signal; in-phase channels; interferometric signal envelope; lock-in amplifier based demodulator; low-noise differential transimpedance amplifier; optical coherence tomography; optical interference signal; photodetector; photoreceiver; quadrature channels; signal detection; signal processing; switched-capacitor low-pass filter; CMOS process; Optical design; Optical filters; Optical interferometry; Optical noise; Optical sensors; Signal design; Signal detection; Stimulated emission; Tomography; Biomedical Imaging; Biomedical imaging; CMOS Analog integrated circuits; CMOS analog integrated circuits; optical tomography; Equipment Design; Equipment Failure Analysis; Image Enhancement; Image Interpretation, Computer-Assisted; Reproducibility of Results; Semiconductors; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Tomography, Optical Coherence;
Journal_Title :
Biomedical Engineering, IEEE Transactions on
DOI :
10.1109/TBME.2007.905402
