Stephen William Smith

Current research interests are the development and evaluation of improved medical ultrasound image quality for applications in cardiology, radiology and obstetrics. Advances in image quality result from improvements in the spatial resolution and signal-to-noise ratio of diagnostic ultrasound scanners through novel signal processing techniques and improved design of ultrasound transducers.

One current project includes the development of two-dimensional phased array transducers for application in the Duke 3-D ultrasound scanner in these N x N, "checkerboard'' arrays are used to steer the ultrasound beam in both the azimuth and elevation directions within the patient's body to interrogate a pyramidal shaped object and produce a volumetric scan at high speeds without moving the transducer.

Recently developed transducers include 100 x 100 = 10,000 element arrays operating at 5-10 MHz. Each square element is only 0.2 mm on a side. In addition, we have developed such 2D arrays to fit inside of intra-cardiac catheters only 2 mm in diameter for guidance of cardiac interventional procedures such as mapping and ablation of atrial fibrillation. Processing technologies include the use of micro electronic packaging and fabrication techniques to develop higher frequency arrays up to 20 MHz with improved resolution and smaller element sizes down to 0.05 mm.