流式分选仪液滴延迟自动校准方法研究

Automated method of calibrating drop delay for flow cytometry

针对现有流式分选仪在工作压力发生变化时难以维持液滴延迟稳定的问题,基于液滴延迟产生机理和射流不稳定性理论,在推导出射流速度随工作压力的数学关系后,又推导出了液滴延迟与工作压力和压电激励幅值的数学关系,提出了通过监测工作压力实现自动校准液滴延迟的方法。通过实验验证了射流速度随工作压力、液滴延迟与工作压力和压电激励幅值的理论计算结果,同时还完成了根据工作压力调节压电幅值后实现液滴延迟稳定的实验。研究结果表明,实验结果与理论计算结果基本一致,进一步研究后还能得到改善;根据工作压力调节压电幅值后实现液滴延迟稳定的方法行之有效,T值误差仅为0.06。这些研究结果可用于指导根据工作压力变化调节压电激励幅度,实现自动校准液滴延迟,提高细胞分选精度。

In order to solve the problem of instability of drop delay in a flow cytometer when the driving pressure changes,a mathematic relationship of jet velocity and the driving pressure was deduced and thereafter a mathematic relation between drop delay and relevant parameters was obtained. The experimental curve of jet velocity and the driving pressure,as well as the relation curves of drop delay and the driving pressure or the piezoelectric signal amplitude were obtained by manual calibration. An experiment of maintaining the drop delay though regulating the piezoelectric signal amplitude according to the driving pressure was conducted as well. A good agreement between the experiment results and the mathematical model was found. The results indicate that,with other conditions unchanged,the drop delay remains stable if the driving pressure and the piezoelectric signal amplitude are kept in certain relationship and it is feasible to maintain the drop delay through monitoring the driving pressure.