Wavelets and short time fourier transforms on ultrasonic doppler signals for pregnancy determination in sheep

Published Article === The reproductive status of animals is of utmost importance to the modern farmer. Decisions concerning the management of the flock are influenced by the knowledge of the percentage of animals that are pregnant at any specific time. The aim of the project was to gain knowledge fo...

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Bibliographic Details
Main Authors: Hertzog, P.E., Jordaan, G.D.
Other Authors: Bloemfontein : Central University of Technology, Free State
Format: Others
Language:en_US
Published: Interim : Interdisciplinary Journal, Vol 5, Issue 1: Bloemfontein : Central University of Technology, Free State 2015
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Online Access:http://hdl.handle.net/11462/414
Description
Summary:Published Article === The reproductive status of animals is of utmost importance to the modern farmer. Decisions concerning the management of the flock are influenced by the knowledge of the percentage of animals that are pregnant at any specific time. The aim of the project was to gain knowledge for the development of an instrument that is affordable and with which a farmer can do pregnancy determination himself/herself, thereby enabling him/her to make the correct management decisions. Experimental data were obtained from pregnant Dorper ewes with the aid of a portable Doppler instrument. Using real data as input, simulations of Wavelet and Short Time Fourier Transforms (STF) were done in MathCAD. In the simulations known levels of noise were added to the Doppler signals. Satisfactory results were obtained from the simulations of Wavelet Transforms. In the simulation of the Wavelet Transforms, signals with a SNR of -6.5 dB were successfully identified. It can thus be concluded that Wavelet Transforms can be used successfully for the detection of the fetal heartbeat in noisy ultrasonic Doppler signals.