Simulation of ultrasound in the knee

A large body of evidence supports the use of low intensity pulsed ultrasound to augment bone healing and similar therapeutic benefits have been observed with damaged joint cartilage. It is an objective of this work to find paths of propagation of ultrasound in the knee and hence the optimal position for the ultrasound device. Determining the above in real tissues is complex and hard to achieve in practical terms; one solution is the use of computer modelling. A number of ultrasound simulation packages are available. In this work, Wave2000Pro (CyberLogic[reg], Inc) has been used to model ultrasound pulses with a frequency of 1·5 MHz in geometries similar in size and shape to knee. These simulations are two dimensional and require a number of assumptions to be made including linear propagation, homogeneity and isotropy of the materials under investigation. Simulations have been performed using Perspex shapes so that the software package could be validated in the laboratory. The outcome of these simulations matches measurements made in the laboratory with two different diameter needle hydrophones