Proceedings Article | 13 June 2023
Connor Propp, Luke Woods, Hamed Taheri Gorji, Kaylee Husarik, Mitchell Sueker, Jianwei Qin, Insuck Baek, Moon Kim, Diane Chan, Stanislav Sokolov, Nicholas MacKinnon, Fartash Vasefi, Kouhyar Tavakolian
KEYWORDS: Contamination, Imaging systems, Fluorescence, Fluorescence imaging, Cameras, Light sources and illumination, Emission wavelengths, Ultraviolet radiation, Chlorophyll, Acquisition tracking and pointing
SafetySpect previously reported the development of a handheld fluorescence imaging system for contamination detection in food facilities using an excitation wavelength of 405 nm. Here we report a dual-excitation fluorescence imaging system including 365 nm and 405 nm LED illumination and a dual camera system for multi-band fluorescence emission image detection. We have measured fluorescence excitation and emission spectra for multiple food residues at the USDA/ARS research laboratory using a Spex spectrofluorometer (JY Inc., Edison, New Jersey). By analyzing emission spectra corresponding to 365 nm and 405 nm excitation wavelengths, we have optimized multi-bandpass optical filters used in our camera systems. We collected image data from multiple kitchen facilities to validate fluorescence imaging capabilities for contamination detection in real-world conditions. Food residue samples evaluated in a laboratory setting included multiple samples of fish, scallops, shrimp, chicken, pork, beef, lamb, fruits, nuts, vegetable oils, condiments, and starches. System performance measurements of the imaging system that were evaluated include characteriz ation of the field of view, working distance, image resolution, image registration, exposure timing accuracy, camera/filter system wavelength response, and dynamic range. System performance measurements of the illumination system that were evaluated includ e wavelength characteristics, exposure control accuracy, camera synchronization accuracy, optical power, linearity of optical power with exposure setting, the field of view, and field uniformity.
