A-MODE ULTRASOUND TECHNIQUE FOR REGISTERING SKULL SURFACE IN COMPUTER-AIDED SURGERY

Author

Uday Kumar Chintapula, Southern Illinois University Carbondale

Date of Award

5-2015

Degree Name

Master of Science

Department

Biomedical Engineering

First Advisor

Botros, Nazeih

Second Advisor

Qin, Jun

Third Advisor

Chen, Ada

Abstract

In computer-aided skull surgery such as brain surgery, the goal or target could be fatal even if missed in millimeters. In a Computer Aided surgery (CAS) the subject is registered to the physical space of the subject in the Operating Room (OR). Registration is a process in which physical space is being matched or overlaid on an image space which is generated from Computed Tomography (CT) / Magnetic Resonance Imaging (MRI). Various markers such as anatomic landmarks, temporary attached markers such as titanium screws, etc. are used to optimize the registration process. Markers such as these attachments to the skull are often accompanied with giving local anesthesia, involving invasiveness leading to inconvenience for the patient. To avoid this inconvenience, A-mode (Amplitude mode) Ultrasound technique can be used for the registration of the skull. A-mode ultrasound technique is used to get surface points from the skull. This device works on the principle of echoes received from the junction of two layers with different acoustic impedance, which in this case is the tissue-bone surface. In this project A-mode ultrasound technique is used to obtain surface points from the surface skull and digitize them using software tools such as MATLAB. Using these A-mode ultrasound readings we can apply reconstruction techniques on the digitized points. These results are acceptable and fairly good. A-mode is more accurate and non-invasive.