| Autor: |
He, Diwei, Kongsavatsak, Chayut, Hayes-Gill, Barrie R., Crowe, John A., Morgan, Stephen P. |
| Předmět: |
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| Zdroj: |
Optical Engineering; May2011, Vol. 50 Issue 5, p054403, 1p |
| Abstrakt: |
A 32×32 pixel array has been fabricated in a 0.35-μm complementary metal-oxide semiconductor process with the aim of producing two-dimensional laser Doppler blood-flow images. In the design, each pixel contains five basic elements: a photodiode, a front-end consisting of a current to voltage converter, voltage amplifier, antialiasing filter, and buffer. The analog design is optimized for the detection of laser Doppler blood-flow signals and thus offers advantages over conventional sensors. The analog outputs are passed through an on-chip multiplexer and digitized by an external analog-to-digital converter. The sensor has been fully characterized electrically and optically using modulated electrical and optical signals. A calibration process for fixed pattern noise reduces the standard deviation of the ac gain by a factor of 2. The imaging response is tested by imaging a vibrating test structure and a rotating diffuser. Blood-flow measurements on a finger before and after occlusion demonstrate that the sensor array is capable of detecting blood-flow signals from tissue. The knowledge gained from the characterization of the design can be used to develop a fully integrated laser Doppler blood-flow sensors with a higher number of pixels. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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