The objective of this work is to develop a medical imaging system for skin burns. Preliminary results indicate that a reflective terahertz (THz) imaging system can be used to image burns on porcine skin with high resolution and high tissue-condition contrast.
Intellectual Merit The proposed system approach is based on conventional radar technology and significantly simplifies the system components and enables near real-time THz imaging. A pulsed photoconductive switch is used as the broadband, free-space-coupled THz transmitter, and an antenna-coupled, zero-bias Schottky diode rectifier is used in the front-end of a time-gated receiver. Both in-vitro data and in-vivo data taken over the course of the proposed work will establish the capabilities of THz imaging of skin burns, and provide a large set of imagery data for future work and for dissemination to the scientific community.
Broader Impact In addition to the direct engineering and medical benefits, the proposed research will also promote student learning and teaching by creating a variety of opportunities, such as intercampus seminars, for meaningful interaction between faculty, clinicians, postdoctoral researchers, graduate students, and undergraduate students on both campuses. For example, a new course on THz Science and Technology will be offered on the UCSB campus Fall of 2008 and will bring in students from Electrical Engineering, Physics, Chemistry, and Biology to a truly interdisciplinary learning environment.
Two THz medical imaging systems were designed, built, characterized, and tested in a research partnership between UCSB and UCLA. UCSB designed a sample scanning and beam scanning system for use in biomedical imaging applications. The scanned sample system raster scanned a target beneath a focused, stationary, THz beams while the scanned beam system used a spinning polygonal mirror and dielectric lens objective to acquire images of stationary targets. The fixed beam imaging system was used to acquire images of partial and full thickness burns induced on ex vivo pig skin samples. These experiments corroborated earlier modeling efforts that changes in hydration are the primary contrast mechanism in burn imaging. Hydration maps were used to analyze the skin burns statistical significance in THz data was established between the 2 burn types Additionally, new electromagnetic models of skin were developed to investigate the spectral characteristics of skin tissue. Debye relaxation theory, Bruggeman effective medium theory, and stratified media theory were used to construct accurate models of skin based on dermatologic data. These modeling results indicate that THz imaging is a good candidate for general skin hydration and specific analysis of skin properties may be feasible with improved THz component technology This grant has lead to the application and awarding of several THz grants from the DoD and NIH to study further THz burn imaging and investigate possible ophthalmologic applications.
