[Design of a Smartphone-Based Portable Corneal Topography Device]

Aiming at the problems of large size, high cost, and poor mobility of traditional corneal topographers, a smartphone-based portable corneal topography device was designed to provide a low-cost and convenient tool for large-scale preliminary screening of corneal diseases.

A small conical Placido disk was used as the core optical component. Its ring distribution was optimized by Matlab and verified by OptisWorks optical simulation, and the miniaturized processing of the Placido disk was realized by laser printing and a PMMA support structure. The device shell was modeled based on SolidWorks and fabricated by 3D printing technology. A red light-emitting diode (LED) lighting system was then designed, arranged in parallel along the angle of the Placido cone and powered by a smartphone to achieve precise adaptation between the device and the smartphone.

The processing errors of the key dimensions of the acrylic cone were small, all less than 0.2 mm. The LED lighting system had a uniform irradiance distribution, and the photobiological safety verification showed that it met the non-hazardous standards. The standard deviation for corneal topography detection was 0.034, which complied with the specifications.

The portable corneal topography device designed in this study meets the measurement standards, achieves miniaturization, low cost, and high adaptability, with uniform and safe lighting, laying a foundation for the practical application of portable corneal topography devices.