Development of advanced non-invasive dynamic photoacoustic and photothermal imaging technologies for biomedical and industrial diagnostics

点击翻译按钮获取中文摘要

The proposed research projects constitute fundamental support of my ongoing research program at the Center for Advanced Diffusion-Wave and Photoacoustic Technologies (CADIPT) toward the development and targeted applications of new advanced photoacoustic (PA), photothermal (PT) and optoelectronic diffusion-wave (DW) imaging technologies pioneered in the CADIPT. In biomedical imaging the proposed research focuses on 3 PA and PT modalities: 1) Wavelength-Modulated Differential Photoacoustic Radar (WM-DPAR); 2) Wavelength-Modulated Differential Photothermal Radiometry (WM-DPTR); and 3) Enhanced Truncated-Correlation Photothermal Coherence Tomography (TC-PCT). The light-to-ultrasound (US) WM-DPAR and light-to-thermal-wave WM-DPTR and TC-PCT energy conversion nature and the very efficient signal baseline suppression of these modalities are very promising for diagnosis of diseases at very early stages and form the major criterion for designing the objectives of the proposed research. WM-DPAR features low-cost continuous wave (CW) laser-wavelength modulation, ~ 2-3 cm depth resolution, and can be integrated into commercial ultrasound imagers to add spectroscopic molecular contrast enhancement to the US image. WM-DPTR operates on laser induced blackbody emissions in the mid-infrared spectral range and features simpler instrumentation than PA, no coupling fluid and portability. TC-PCT is a high axial-resolution (25 um) PT 3D imaging method, also based on laser-induced mid-infrared photon emissions and ~4 mm depth resolution. Applications of the aforementioned modalities are proposed in three major areas: 1) Minimally- invasive clinically compatible WM-DPAR catheter development for early coronary artery disease (atherosclerosis) diagnosis; 2) A non-invasive WM-DPTR cannabis sensor for roadside monitoring of impaired driver tetrahydrocannabinol (THC; the psychoactive component of cannabis) interstitial fluid (strongly related to blood) concentration; and 3) Real-time noninvasive measurements of brown fat metabolism based on eTC-PCT imaging of hemoglobin time transients (gradients) in healthy and obese/diabetic mice, subjected to a high fat diet.. It is also proposed to develop Ultra-High Frequency Heterodyne Lock-In Carrierography (UHF-HeLIC) imaging as a unique non-contacting nondestructive optoelectronic DW inspection tool of entire surface areas of semiconductors, specifically rapid-growth clean energy ultrathin photovoltaic Si solar cell technologies. A unique feature of UHF-He LIC is that it can replace conventional localized electrical testing requiring finished electronic devices with all-optical noncontact measurements of e.g. current-voltage characteristics, allowing fast, wafer-level inspections at any and all device fabrication stages with no need for electrical leads. The imaging will identify and help minimize optoelectronic surface and bulk traps and assess the effectiveness of surface passivation and wet cleans in ultrathin PV devices.