Ultrasonic Bone Mineral Density Analysis Based On Wavelet Transform

With the development of medical science and technology,the diagnosis of osteoporosis is no longer a difficult thing.In many detection techniques,ultrasound bone density instrument because of its portability,low price and accuracy is well received.The ultrasonic bone densitometer designed in this paper is mainly an instrument based on the critical angle side wave principle.Moreover.it is a equipment to measure bone mineral density by measuring the speed of ultrasonic transmission in cortical bone.The parameters measured by the bone density instrument are SOS,T Score and Z_score,etc.,because the T_Score and Z_Score can be calculated according to the SOS and the standard reference value,so the accuracy and complexity of the measurement of SOS is very important.In the axial transmission ultrasonic bone density instrument,its basic principle is based on the arrival time of the first arrival wave(First Arrived,Signal,FAS)to calculate the SOS.Since the amplitude of the first arriving wave is small relative to the reflected wave,therefore,it is a great challenge to accurately extract the arrival time of first arrival wave when the SNR is not high.The existing commercial systems also have problems in this area.Generally on the basis of the algorithm of extracting FAS,the statistical method is used to calculate the velocity of sound by multiple measurements.The method of wavelet transform in time-frequency analysis has inherent advantages.Therefore,this paper explores the application of wavelet transform in the detection of the first wave.This paper designs and develops a bone density analysis software that can accurately and efficiently measure radial SOS,based on VS2013 platform,using C#language.The equipment is based on the principle of axial transmission detection,the first arrival wave is extracted and the velocity of sound is calculated by wavelet transform,and the result is compared with the method of cross correlation.Firstly,this paper introduces the background of the research.Secondly,the paper analyzes of the principle of ultrasound bone density.Lastly,this paper describes the functions of real-time display,acquisition,data analysis,information storage and printing reporting of the data in this system.Several tests show that the wavelet transform algorithm with the set of software design can get more accurate ultrasonic data.The equipment is more accurate and reproducible.