Compact and low-cost deep-ultraviolet microscope system for label-free molecular imaging and point-of-care hematological analysis

Abstract

Deep-ultraviolet (UV) microscopy enables label-free, high-resolution, quantitative molecular imaging and enables unique applications in biomedicine, including the potential for fast hematological analysis at the point-of-care. UV microscopy has been shown to quantify hemoglobin content and white blood cells (five-part differential), providing a simple alternative to the current gold standard, the hematological analyzer. Previously, however, the UV system comprised a bulky broadband laser-driven plasma light source along with a large and expensive camera and 3D translation stage. Here, we present a modified deep-UV microscope system with a compact footprint and low-cost components. We detail the novel design with simple, inexpensive optics and hardware to enable fast and accurate automated imaging. We characterize the system, including a modified low-cost web-camera and custom automated 3D translation stage, and demonstrate its ability to scan and capture large area images. We further demonstrate the capability of the system by imaging and analyzing blood smears, using previously trained networks for automatic segmentation, classification (including 5-part white blood cell differential), and colorization. The developed system is approximately 10 times less expensive than previous configurations and can serve as a point-of-care hematology analyzer, as well as be applied broadly in biomedicine as a simple compact, low-cost, quantitative molecular imaging system.

Deep learning-based analysis of deep ultraviolet (UV) microscopy images for label-free, point-of-care hematological analysis

“…Consequently, it is straightforward, easy to implement, and more cost-effective than many conventional methods. We have demonstrated our UV microscopy system in a low-cost and compact configuration, costing <$5000, 24 in contrast to the bulky and expensive commercial analyzers, which typically range from $80,000 and $120,000. Our method is both fast and efficient, capable of imaging and analyzing a 1mm X 2mm area (containing ¿20,000 cells) in approximately 3 minutes.…”

“…Deep ultraviolet microscopy (UV) is a label-free imaging technique that relies on the characteristic spectral properties of endogenous biomolecules in this region of the spectrum (200-400 nm) to yield quantitative molecular and structural information from biological samples. 16,17,18,19,20,21,22,23,24 Deep-UV microscopy offers a higher spatial resolution than conventional methods because of the shorter wavelength of UV light. In addition, deep-UV microscopy enables contiguous imaging of live cells over long durations (> 6 hrs) without significant photodamage.…”

Deep-ultraviolet microscopy for analysis of bone marrow aspirate adequacy

“…Deep-ultraviolet (UV) microscopy enables label-free, high-resolution, quantitative molecular imaging by leveraging unique absorption properties of biomolecules, such as nucleic acids, in the UV region of the spectrum (200-400nm) [5][6][7][8]. Recently, it has been demonstrated for fast hematology analysis of whole blood smears and blood samples in custom microfluidic cartridges for point-of-care applications enabled by advancements in low-cost UV LEDs and sensors [9][10][11][12][13]. UV microscopy has also been used for multi-spectral, label-free histopathology of tissue samples [14][15][16].…”

“…UV microscopy has also been used for multi-spectral, label-free histopathology of tissue samples [14][15][16]. In these prior works, deep neural networks have been required to pseudo-colorize images to mimic conventional biochemical stains (i.e., hematoxylin and eosin, Giemsa) [12,13,15]. In this study, we demonstrate a portable, LED-based UV microscope designed for rapid inspection of bone marrow aspirates, including real-time pseudo-colorization via a colormap transformation without any artificial intelligence (AI).…”

“…We discuss results obtained from a clinical trial involving aspirate adequacy assessment from 51 pediatric patients showing excellent agreement between UV inspection of unstained slides and pathologist examination of stained slides. Furthermore, we demonstrate whole slide imaging with a previously developed low-cost UV system [13] and automated spicule detection via deep neural networks. Ultimately, we show that this device can be translated for bone marrow aspirate analysis in point-of-care applications.…”