09-02-2010, 07:48 PM
11-02-2010, 02:50 PM
Implementation Of Zoom Fft
In Ultrasonic Blood Flow Analysis
Analysis of
the blood flow finds its importance in the diagnoses of diseases. The present techniques are not affordable by the poor people
because of their high expense.Zoom-FFT technique is simple and affordable to detect the blood clots and other diseases.the method to zoom the image or the scanned data-using zoom FFT has been
discussed. the algorithm to get ZOOM FFT and how it can be obtained via
simulation is explained. ultrasonic blood
flow analyzer using ZOOM FFT is explained as an application of this method.
REAL BLOOD FLOW ANALYSIS:
In an Ultrasonic blood flow analysis, a beam of ultrasonic energy is directed
through a blood vessel at a shallow angle and its transit time is then measured. ultrasonic analyzers based on the Doppler principle are much more common.
Need to ZOOM:
Minute variations in blood flow can be seenfor example, the starting stage of blood clot.
ZOOM FFT:
The Zoom-FFT is a process where an input signal is mixed down to baseband
and then decimated, prior to passing it into a standard FFT.the zoom-FFT uses digital down conversion techniques to localize the
standard FFT to a narrow band of frequencies that are centered on a higher frequency. It is used to reduce the sample rate required when analyzing narrowband signals. Basically, this technique is an efficient computation of a subset of the FFT.
the zoom process:
1)the basic architecture of the Zoom-FFT:
Spectrum analyzers originally provided the zoom FFT to offer higher frequency resolution over a specific bandwidth, given the limitation of a small amount of on-board memory. very fine frequency resolution can be obtained without computing the entire spectrum by using zoomFFT. Digital zoom (frequency domain) is usually implemented by multiplying the input signal
with a sine and cosine at a new desired center frequency, and then low-pass filtering the
data, followed by sampling rate reduction (decimation).
ADVANTAGES
a)Increased frequency domain resolution
b)Wider spectral range
c)Reduced hardware cost and complexity
report:
[attachment=1918]
In Ultrasonic Blood Flow Analysis
Analysis of
the blood flow finds its importance in the diagnoses of diseases. The present techniques are not affordable by the poor people
because of their high expense.Zoom-FFT technique is simple and affordable to detect the blood clots and other diseases.the method to zoom the image or the scanned data-using zoom FFT has been
discussed. the algorithm to get ZOOM FFT and how it can be obtained via
simulation is explained. ultrasonic blood
flow analyzer using ZOOM FFT is explained as an application of this method.
REAL BLOOD FLOW ANALYSIS:
In an Ultrasonic blood flow analysis, a beam of ultrasonic energy is directed
through a blood vessel at a shallow angle and its transit time is then measured. ultrasonic analyzers based on the Doppler principle are much more common.
Need to ZOOM:
Minute variations in blood flow can be seenfor example, the starting stage of blood clot.
ZOOM FFT:
The Zoom-FFT is a process where an input signal is mixed down to baseband
and then decimated, prior to passing it into a standard FFT.the zoom-FFT uses digital down conversion techniques to localize the
standard FFT to a narrow band of frequencies that are centered on a higher frequency. It is used to reduce the sample rate required when analyzing narrowband signals. Basically, this technique is an efficient computation of a subset of the FFT.
the zoom process:
1)the basic architecture of the Zoom-FFT:
Spectrum analyzers originally provided the zoom FFT to offer higher frequency resolution over a specific bandwidth, given the limitation of a small amount of on-board memory. very fine frequency resolution can be obtained without computing the entire spectrum by using zoomFFT. Digital zoom (frequency domain) is usually implemented by multiplying the input signal
with a sine and cosine at a new desired center frequency, and then low-pass filtering the
data, followed by sampling rate reduction (decimation).
ADVANTAGES
a)Increased frequency domain resolution
b)Wider spectral range
c)Reduced hardware cost and complexity
report:
[attachment=1918]
18-04-2010, 11:10 PM
please read http://studentbank.in/report-implementat...w-analysis and http://studentbank.in/report-implementat...ysis--7188 for getting more information about Implementation Of Zoom FFT in Ultrasonic Blood Flow Analysis