Harput, S, Evans, JA, Bubb, N and Freear, S (2011) Diagnostic Ultrasound Tooth Imaging using Fractional Fourier Transform. IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 58 (10). 2096 - 2106 . ISSN 0885-3010
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An ultrasound contact imaging method is proposed to measure the enamel thickness in human tooth. A delay-line transducer with a working frequency of 15 MHz is chosen to achieve a minimum resolvable distance of 400 μm in human enamel. To confirm the contact between the tooth and the transducer, a verification technique based on the phase shift upon reflection is used. Because of the high attenuation in human teeth, linear frequency modulated chirp excitation and pulse compression are exploited to increase the penetration depth and improve the signal-to-noise ratio. Preliminary measurements show that the enamel-dentin boundary creates numerous internal reflections, which cause the applied chirp signals to interfere arbitrarily. In this work, the fractional Fourier transform (FrFT) is employed for the first time in dental imaging to separate chirp signals overlapping in both time and frequency domains. The overlapped chirps are compressed using the FrFT and matched filter techniques. Micro-CT is used for validation of the ultrasound measurements for both techniques. For a human molar, thickness of the enamel layer is measured with an average error of 5.5% after compressing with the FrFT and 13.4% after compressing with the matched filter based on average speed of sound in human teeth.
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Engineering (Leeds) > School of Electronic & Electrical Engineering (Leeds)
The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Dentistry (Leeds)
|Depositing User:||Symplectic Publications|
|Date Deposited:||23 Feb 2012 15:18|
|Last Modified:||08 Feb 2013 17:36|
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Diagnostic Ultrasound Tooth Imaging using Fractional Fourier Transform. (deposited 18 Jul 2011 11:15)
- Diagnostic Ultrasound Tooth Imaging using Fractional Fourier Transform. (deposited 23 Feb 2012 15:18) [Currently Displayed]