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Title: Full field laser doppler blood flow camera
Author: Kongsavatsak, Chayut
ISNI:       0000 0001 3601 6969
Awarding Body: University of Nottingham
Current Institution: University of Nottingham
Date of Award: 2005
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Laser Doppler Blood Flowmetry is a non-invasive technique that has been I developed and used for measuring microvascular blood flow in tissue. The technique utilises the backscattering of the laser light from moving red blood cells and static tissue in order to extract information such as the concentration and flow. This thesis describes the early stages of the development of an integrated optical sensor array to perform full field laser Doppler blood flow imaging. This technique will eliminate the need for mechanical scanning and the data bottleneck that exists between the photodiode array and processing unit, so allowing the direct measurement ofblood flow maps to be obtained in real time. A single channel laser Doppler blood flowmetry device has been implemented using a photodetector linked to a field programmable gate array. Filters (low pass, band pass and frequency weighted) have been developed for processing the Doppler signals to obtain flow and concentration measurements. The responses of these filters are demonstrated using measurements from modulated light signals, a rotating diffusing disc and in vivo measurements of blood flow. Several types of a linear array system and current to voltage converter are considered for the first fabrication run of the project based on the cost of fabrication and performance of the system such as operating frequency, gain, bandwidth and signal to noise ratio. A 16x1 linear array of photodiodes is developed and integrated on the same chip with the laser Doppler processing design, successfully implemented in the single channel laser Doppler system, using the standard 0.35Jlm CMOS technology. The characterisation of each individual part of the design was carried out and compared with the Cadence simulation results. The performance of the system on a single pixel is also evaluated using a modulated laser as a light source. The knowledge gained from the characterisation and the overall performance of the linear array system is then used to develop a full field laser Doppler blood flow camera.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available