An Innovative Miniaturized Cell Imaging System Based on Integrated Coaxial Dual Optical Path Structure and Microfluidic Fixed Frequency Sample Loading Strategy.

On-site rapid detection of cells is especially of concern for many fields; image-based detection results can directly reflect multidimensional information such as cell contour and aggregation state. This article proposes an innovative miniaturized cell imaging system based on an integrated coaxial dual optical path structure and microfluidic fixed frequency sample loading strategy, which performs synchronous imaging of bright field mode and fluorescence field mode on cells. The bright field optical path and fluorescence field optical path are integrated into the coaxial dual optical path structure based on the dichroic mirror with splitting and steering functions. The movement of the shutter's curtain is controlled by a micromotor so that the plane mirrors fixed on the curtain with different light angles can be switched to the optical axis, and the fast switching of the bright field optical path and the fluorescence field optical path can be implemented. A drawer-type filter module can be pulled out of the coaxial dual optical path structure, and the emission filter and the dichroic mirror in this module can be replaced according to the fluorescence emission peak of the sample to be tested, thereby expanding the detectable cell types of this system. In addition, based on the force analysis and calculation of the fluid, a fixed frequency was obtained to drive the sample loading. The accumulated kinetic energy of the fluid during this period can be offset by the closing of the pinch valve, and the flow rate of the sample in the imaging field can be rapidly reduced to close to zero to avoid the tailing effect in the image. It is experimentally confirmed that the detection accuracy of this system, the registration matching accuracy of cells and fluorescent dots, the cell survival rate, and the detection sensitivity of cell viability. This system balances the tradeoff between portability, flux, and accuracy, and offers more functionality in terms of technology and application for on-site cell detection.