title: Field-portable wide-field microscopy of dense samples using multi-height pixel super-resolution based lensfree imaging.
abstract: We report a field-portable lensfree microscope that can image dense and connected specimens with sub-micron resolution over a large field-of-view of ~30 mm(2) (i.e., ~6.4 mm × ~4.6 mm) using pixel super-resolution and iterative phase recovery techniques. Weighing ~122 grams with dimensions of 4 cm × 4 cm × 15 cm, this microscope records lensfree in-line holograms of specimens onto an opto-electronic sensor-array using partially coherent illumination. To reconstruct the phase and amplitude images of dense samples (with >0.3 billion pixels in each image, i.e., >0.6 billion pixels total), we employ a multi-height imaging approach, where by using a mechanical interface the sensor-to-sample distance is dynamically changed by random discrete steps of e.g., ~10 to 80 μm. By digitally propagating back and forth between these multi-height super-resolved holograms (corresponding to typically 2-5 planes), phase and amplitude images of dense samples can be recovered without the need for any spatial masks or filtering. We demonstrate the performance of this field-portable multi-height lensfree microscope by imaging Papanicolaou smears (also known as Pap tests). Our results reveal the promising potential of this multi-height lensfree computational microscopy platform for e.g., pathology needs in resource limited settings.
authors.affiliation: UCLA Electrical Engineering Department, University of California, Los Angeles, CA 90095, USA.
authors.forename: Alon
authors.initials: A
authors.lastname: Greenbaum
authors.forename: Uzair
authors.initials: U
authors.lastname: Sikora
authors.forename: Aydogan
authors.initials: A
authors.lastname: Ozcan
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D007909:Lenses; D008853:Microscopy; D065006:Papanicolaou Test; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis; D014626:Vaginal Smears