title: Low-cost telemedicine device performing cell and particle size measurement based on lens-free shadow imaging technology.
abstract: Recent advances in lens-free shadow imaging technology have enabled a new class of cell imaging platform, which is a suitable candidate for point-of-care facilities. In this paper, we firstly demonstrate a compact and low-cost telemedicine device providing automated cell and particle size measurement based on lens-free shadow imaging technology. Using the generated shadow (or diffraction) patterns, the proposed approach can detect and measure the sizes of more than several hundreds of micro-objects simultaneously within a single digital image frame. In practical experiments, we defined four types of shadow parameters extracted from each micro-object shadow pattern, and found that a specific shadow parameter (peak-to-peak distance, PPD) demonstrated a linear relationship with the actual micro-object sizes. By using this information, a new algorithm suitable for operation on both a personal computer (PC) and a cell phone was also developed, providing automated size detection of poly-styrenemicro-beads and biological cells such as red blood cells, MCF-7, HepG2, and HeLa. Results from the proposed device were compared with those of a conventional optical microscope, demonstrating good agreement between two approaches. In contrast to other existing cell and particle size measurement approaches, such as Coulter counter, flow-cytometer, particle-size analyzer, and optical microscope, this device can provide accurate cell and particle size information with a 2 µm maximum resolution, at almost no cost (less than 100 USD), within a compact instrumentation size (9.3×9.0×9.0 cm(3)), and in a rapid manner (within 1 min). The proposed lens-free automated particle and cell size measurement device, based on shadow imaging technology, can be utilized as a powerful tool for many cell and particle handling procedures, including environmental, pharmaceutical, biological, and clinical applications.
authors.affiliation: Department of Electronics and Information Engineering, Korea University, Sejong, Republic of Korea.
authors.forename: Mohendra
authors.initials: M
authors.lastname: Roy
authors.affiliation: Department of Electronics and Information Engineering, Korea University, Sejong, Republic of Korea.
authors.forename: Dongmin
authors.initials: D
authors.lastname: Seo
authors.affiliation: Department of Electronics and Information Engineering, Korea University, Sejong, Republic of Korea.
authors.forename: Chang-Hyun
authors.initials: CH
authors.lastname: Oh
authors.affiliation: Department of Laboratory Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea.
authors.forename: Myung-Hyun
authors.initials: MH
authors.lastname: Nam
authors.affiliation: Department of Food and Biotechnology, Korea University, Sejong, Republic of Korea.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Electronics and Information Engineering, Korea University, Sejong, Republic of Korea. Electronic address: sseo@korea.ac.kr.
authors.forename: Sungkyu
authors.initials: S
authors.lastname: Seo
mesh_terms: D015374:Biosensing Techniques; D005434:Flow Cytometry; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D061986:MCF-7 Cells; D057054:Molecular Imaging / Q000379:methods*; D010316:Particle Size; D017216:Telemedicine
keywords: CMOS image sensor; Cell size measurement; Diffraction; Lens-free imaging; Shadow