title: Automatic real time evaluation of red blood cell elasticity by optical tweezers.
abstract: Optical tweezers have been used to trap, manipulate, and measure individual cell properties. In this work, we show that the association of a computer controlled optical tweezers system with image processing techniques allows rapid and reproducible evaluation of cell deformability. In particular, the deformability of red blood cells (RBCs) plays a key role in the transport of oxygen through the blood microcirculation. The automatic measurement processes consisted of three steps: acquisition, segmentation of images, and measurement of the elasticity of the cells. An optical tweezers system was setup on an upright microscope equipped with a CCD camera and a motorized XYZ stage, computer controlled by a Labview platform. On the optical tweezers setup, the deformation of the captured RBC was obtained by moving the motorized stage. The automatic real-time homemade system was evaluated by measuring RBCs elasticity from normal donors and patients with sickle cell anemia. Approximately 150 erythrocytes were examined, and the elasticity values obtained by using the developed system were compared to the values measured by two experts. With the automatic system, there was a significant time reduction (60×) of the erythrocytes elasticity evaluation. Automated system can help to expand the applications of optical tweezers in hematology and hemotherapy.
authors.affiliation: Laboratory of Biomedical Optics and Imaging, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Diógenes S
authors.initials: DS
authors.lastname: Moura
authors.affiliation: College of Biological Sciences, Federal University of Vale do São Francisco-UNIVASF, Petrolina, Pernambuco, Brazil.
authors.forename: Diego C N
authors.initials: DC
authors.lastname: Silva
authors.affiliation: Laboratory of Biomedical Optics and Imaging, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Ajoke J
authors.initials: AJ
authors.lastname: Williams
authors.affiliation: Department of Biophysics and Radiobiology, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Marcos A C
authors.initials: MA
authors.lastname: Bezerra
authors.affiliation: Laboratory of Biomedical Optics and Imaging, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Fontes
authors.affiliation: Laboratory of Biomedical Optics and Imaging, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Renato E
authors.initials: RE
authors.lastname: de Araujo
mesh_terms: D048588:Benzoxazines / Q000737:chemistry; D004548:Elasticity; D004912:Erythrocytes / Q000502:physiology*; D052898:Optical Tweezers; D010363:Pattern Recognition, Automated / Q000379:methods*; D010472:Perchlorates / Q000737:chemistry; D013057:Spectrum Analysis; D014732:Vibration
chemical_list: D048588:Benzoxazines; D010472:Perchlorates; C028911:cresyl violet; C494474:perchlorate