Background
Microscopy is a standard diagnostic tool for many medical conditions. Despite this, microscopy is inaccessible in many regions of the world - especially in endemic regions like Africa, which lack either the equipment or the means to transport it to locations where it is needed. SmartPolar addresses this inaccessibility through the development of a portable, polarized light microscope attachment for smartphones that can be used in medical diagnostics. Final design is capable of resolving blood smears at 14.4pixels/μm, with a field-of-view of 100μm x 100μm. It is comparable to 280x magnification on a standard microscope, and has polarizing capability to detect birefringence (useful in malarial detection).
Scope
Smartphone diagnostic tools provide a cost-effective solution, allowing health professionals to more easily bring diagnosis to the point of care, and facilitating the possibility of remote image analysis by immunologists. The goal of this project was to develop an inexpensive, portable, smartphone-compatible polarized light microscope that requires little external power and that can examine biological samples on glass slides. It will allow web-based sharing of images generated using the smartphones’ innate capabilities.
More information at: www.ucsdplm.weebly.com
Rapid Prototyping
Rapid prototyping of the optical stand was used to determine the range of distances that the microscope's objective and condenser lenses would be working with. Optical bench prototype allowed for a fast and effective way to move lenses linearly along the smartphone's optical path.
Rapid prototype of microscope stand (Harriet Hu)
Optical bench with optical lenses sliders with UV-cured lenses
Solidworks prototype of microscope housing (Harriet Hu)
Featuring optical tube that houses objective and condenser lenses, microscope slide slot, and polarizers.
Final Design
Eyepiece and objective lenses were arranged according to empirically-determined distances to achieve 14.6 pixels/mm resolution. Two cross-polarizing sheets were integrated to vary the orientation of light through the specimen and to produce interference patterns characteristic of birefringent materials. Optical components were mounted on a 3D-printed housing of acrylonitrile butadiene styrene, which secured and protected the optical components. A fine-focus mechanism and a metal clip were included to provide specimen stability, increase image quality, and provide the capacity to view more regions of specimens.
Final Solidworks assembly of SmartPolar system
User testing at the UC San Diego's School of Medicine
User testing SmartPolar microscope paired with Samsung phone to detect birefringence in malarial blood smears. Resolution of camera: 14.4pixels/um
SmartPolar, back view of optical train
SmartPolar, front view of diagnostic capabilities
Imaging blood samples
Shark Tank Competition
SmartPolar won the Eugene H. Mead Memorial Award for Best Senior Design Research, and was voted to present at the 15th Annual UC Bioengineering Symposium. The team entered into the Student Shark Tank to compete against other capstone and industry ventures.
15th Annual University of California Bioengineering Symposium (UC Irvine, June 2014)
Harriet Hu pitching SmartPolar in front of VCs, academic scholars, and peers
