Portable Multi-functional Optical Microscopic Smart Testing System

Optical testing refers to technology to measure and calculate subject' structure using optical method.While in these methods,some are based on indirect imaging,like scattering and spectrum detection;others are based on direct imaging,like bright field,fluorescent imaging and phase imaging.However,these platforms are complicated in structure and huge in size,and it takes a long time to get the results,which cannot meet the needs of point of care testing.Point of care testing,or bedside testing,means the first-time medical diagnosis on patients besides them,and has many advantages like quick access to results,easy to perform and low cost,which is gaining more and more attention.To meet the needs of point of care testing,many miniaturized testing platforms have been proposed.The goal of this paper is to develop a miniaturized imaging system which can perform fast quantitative phase imaging.Miniaturized microscopic imaging system was first designed.Since the phase retrieve method,transport of intensity equation method,has advantages like intuitive imaging results,low illumination coherence demand,and short phase retrieve time.Due to these advantages,in this paper we proposed a quantitative phase microscope based on transport of intensity method combining this method.By building the microscopic system that can capture images of different focal planes,it can perform TIE phase retrieval.Utilizing cheap LED as light source,the objective and eyepiece can magnify the specimen's image.Defocused sample image can be captured using software without mechanical moving.We designed and fabricated 3D printed shell and all parts of the system can be integrated in it which can be held with one hand.The phase retrieval program is written based on fast Fourier transform,and Android and computer based applications are programmed on order to shorten the processing time.The smartphone application can read the captured images conveniently,and get the retrieved phase in a short time after inputting the parameters,making the whole much more efficient.As the defocus distance has great influence on the results,we did the calibration first,connecting smartphone's focus value and sample defocus distance.To certificate the system's accuracy,the phase retrieval result of random phase plate was compared with that if AFM measured one,and they were in accordance with each other.Combing with error analysis,the accuracy of phase retrieval was certificated.The phase of red blood smear was tested and statistics like area,volume and roundness are analyzed using mathematical morphology.Several biological samples were tested at last to demonstrate the phase retrieve capability.The proposed quantitative phase imaging system is miniature in size,and when compared with commercial microscopes,it's more cost-effective,easier to operate and faster to get the results.It can not only get the bright field microscopic and quantitative phase image of samples,but also analyze their morphology statistics.The miniaturized quantitative phase imaging system can meet the needs of POCT,and not only offers a rapid analyze method for medical staff,but also become a promising tool in medical diagnosis in remote areas because of its portable and cheap advantages.