Research

Research activities are focused on biomedical ultrasound imaging, tissue characterization, and non-invasive material characterization. The following are ongoing research projects at our laboratory.

Quantitative Ultrasonography for Periodontal Bone Attachment in Human Jaws

The problem of detecting defects in jawbones is an important problem. Existing methods based on X-rays are invasive and constrain the achievable image quality. They may also carry known risks of cancer generation or maybe limited in accurate diagnosis scope. This work is motivated by the lack of current imaging modalities to accurately predict the mechanical properties and defects in jawbone. In our laboratory, we are developing several ultrasound based systems that can be used non-invasively to characterize and image human mandibles (jawbone). Ultrasound guided waves, A-scans, B-scans, and C-scans can be used for this purpose. Both in vitro and in vivo studies are running to fully evaluate these systems.

 

• A. M. Mahmoud, P. Ngan, R. Crout, and O.M. Mukdadi, “ High-resolution 3D ultrasound jawbone surface imaging for diagnosis of periodontal bony defects: An in vitro study,” Annals Review of Biomedical Engineering, Vol. 38 (11), pp. 3409-3422, 2010.

In Vivo Real-Time Ultrasonic Characterization of Cardiovascular Tissues Using Strain Rate Imaging

Several Quantitative Ultrasound (QUS) techniques have been proposed recently to non-invasively characterize human tissues. In cardiovascular research, wall elasticity is of high clinical interest because of its correlation with different cardiovascular diseases. In this research, we are trying to measure the change of normal and shear stresses directly from different cardiovascular walls over the time. Sonographic measurements of flow-medicated dilation (FMD) can be used to obtain the strain rate imaging which can be used to track wall changes over the time.

 

• A.M. Mahmoud, J.C. Frisbee, A. D’Audiffret, and O.M. Mukdadi, “ In vivo vascular wall tissue characterization using a strain tensor measuring (STM) technique for flow-mediated vasodilatation analyses,” Physics in Medicine and Biology, Vol. 54, pp. 6217–6238, 2009.

Laser Ultrasonic Characterization of Thin Films Using Elastic Guided Waves

In the study of the thin films and similar structures, it is important to measure and analyze the displacement field of the traveling waves. The mode shapes and resonance frequencies can be used to characterize the mechanical properties of the sample. Laser interferometry is a technique to measure out-of-plane displacements with high accuracy and spatial resolution. The equipment available in the laboratory allows measuring the displacements with sub-nanometers resolution on samples as large as 300mm x 300mm.

• O.M. Mukdadi, S.K. Datta, K.L. Telschow, and V.A. Deason, " Off-axis propagation of ultrasonic guided waves in thin orthotropic layers: theoretical analysis and dynamic holographic imaging measurements," IEEE Transactions on Ultrasonics, Ferroelectrics, Frequency Control, Vol. 48, no. 6, pp. 1581-1593, 2001.

Non-destructive ultrasonic evaluation of CFRP–concrete specimens

The objective of this work is to utilize surface acoustic waves (SAWs) for non-destructive structural health monitoring of concrete specimens externally bonded with carbon fiber-reinforced polymer (CFRP) composites and subjected to accelerated aging conditions.

 

• A.M. Mahmoud, H.H. Ammar, O.M. Mukdadi, I. Ray, F. Imani, A. Chen, and J.F. Davalos, “ Non-destructive ultrasonic evaluation of CFRP-concrete specimens subjected to accelerated aging conditions,” NDE& T International , Vol. 43, pp. 635–641, 2010.

Finite-Element Analysis in Orthopedics and Dentistry

Ongoing research is focused on finite-element modeling of tooth implants in density, and knee and hip implants in orthopedics. 3D printable functionally graded materials have been investigated and modeled with finite-element analysis under static and dynamics loadings. Orthodontic treatment protocol shave been investigated as a pre-operative clinical tool. In this research, we are delivering translational research from lab to clinic to optimize therapy and implant design and procedure.

 

• A.Z. Arab, A. Merdji, A. Benaissa, S. Roy, B. Bouiadjra, K. Layadi, A. Ouddane, O. M Mukdadi, “ Finite-element analysis of a lateral femoro-tibial impact on the total knee arthroplasty,” Computer Methods and Programs in Biomedicine, Vol. 192, 105446, 2020.
• A. Ouldyerou, H. Mehboob, A. Merdji, L. Aminallah, A. Mehboob, O. M. Mukdadi, “ Biomechanical analysis of printable functionally graded material (FGM) dental implants for different bone densities”, Computer Methods and Programs in Biomedicine, 2022, (in press)

3D Nonlinear Elastography of Breast Masses

The main objective of this work is to develop a new nonlinear elastography based classification method for human breast masses. Multi-compression elastography imaging is elucidated in this study to differentiate malignant from benign lesions, based on their nonlinear mechanical behavior under compression. this novel elastography technique can be used as a noninvasive pre-biopsy tool for breast cancer, with the capability of visualizing and separating the masses in a three dimensional space. This may reduce the number of unnecessary painful breast biopsies.

   

• A. Sayed, G. Layne, J. Abraham, and O. M. Mukdadi, “ Nonlinear characterization of breast cancer using multi-compression 3D ultrasound elastography in vivo ,” Ultrasonics, Vol. 53, pp. 979-91, 2013. 
• A. Sayed, G. Layne, J. Abraham, O. M. Mukdadi, “ 3D visualization and nonlinear tissue classification of breast tumors using ultrasound elastography in vivo ,” Ultrasound in Medicine and Biology, Vol. 40(7), pp. 1490-1502, 2014.