An Embedded Cytometer for Autonomous Platforms

光合微生物-浮游植物-每年产生约50%的地球上产生的氧气和有机物质，并作为海洋食物网的基础。流式细胞仪是快速准确测量单个浮游植物细胞的丰度、大小和荧光特征的重要海洋仪器。例如，流式细胞术导致了地球上最丰富的光合生物原绿球藻的发现。然而，三十七年后的第一个描述的流式细胞仪专门设计用于测量浮游植物在现场，流式细胞术的复杂性，它产生的多参数数据继续是一个障碍，其演变为共同使用的海洋领域的仪器。PipeCyte是一种微型、低功耗流式细胞仪，设计用于在自主海洋测量平台上进行0.5-10 µm直径浮游植物的自主测量。在第一个部署项目中，PipeCyte仪器将被浸没在100米的深度，同时拴在水面浮标上。水面浮标是一种低成本平台，易于从研究船上部署。在该项目中，将在公海释放几个浮标部署的PipeCyte仪器，以测量多个深度的浮游植物群落。这些测量将提供一个前所未有的看法之间的关系，环境特征和浮游植物群落沿着水柱。先前开发的PipeCyte原型将通过重新设计和重新包装定制采集和控制电路来迭代，以降低尺寸和功耗要求。这种新型低于20瓦的PipeCyte V2将安装在市售压力外壳内。在实验室使用校准微球和培养的浮游植物进行仪器校准后，将在普吉特海湾对浮子系留仪器进行初步现场测试。以前在R中开发的用于分析SeaFlow流式细胞仪数据的自动数据分析方法将被移植到基于PipeCyte Labview的控制软件中，以便多参数流式细胞仪数据可以实时减少到浮游植物种群计数。该简化数据集沿着GPS定位将通过卫星调制解调器传回船舶和海岸。拟议部署在地面的仪器将由4个100瓦时锂电池供电，每次部署的仪器工作时间约为50小时。最终的现场测试将在亚热带太平洋进行，以证明概念验证，届时原绿球藻、聚球藻和小型真核浮游植物的实时计数将广播到船上。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

The photosynthetic microbes – the phytoplankton – generate about 50% of the oxygen and organic matter produced on Earth each year and serve as the base of marine food webs. Flow cytometers are essential oceanographic instruments that rapidly and accurately measure the abundance, size and fluorescent characteristics of individual phytoplankton cells. For example, flow cytometry led to the discovery of Prochloroccocus, the most abundant photosynthetic organism on Earth. However, thirty-seven years after the first description of a flow cytometer designed specifically for the measurement of phytoplankton in the field, the complexity of flow cytometry, and the multi-parametric data it produces continues to be an obstacle to its evolution towards common use as an oceanographic field instrument. PipeCyte is a miniature, low-power flow cytometer instrument that was designed to perform autonomous measurements of 0.5-10 µm diameter phytoplankton while deployed on autonomous oceanographic measurement platforms. In this first deployment project, the PipeCyte instrument will be immersed at depths of up to 100 meters while tethered to a surface buoy. A surface buoy is a low-cost platform that is simple to deploy from a research vessel. In this project, several buoy deployed PipeCyte instruments will be released in the open ocean to perform measurements of the phytoplankton community at multiple depths. These measurements will provide an unprecedented view of the relation between environmental features and phytoplankton communities along the water column. A previously developed PipeCyte prototype will be iterated to reduce both size and power requirement through a redesign and repackaging of the custom acquisition and control circuitry. This new sub-20 watt PipeCyte V2 will be housed within a commercially available pressure housing. After instrument calibration in the lab using calibration microspheres and cultured phytoplankton, initial field testing of a float-tethered instrument will be performed in the Puget Sound. Automated data analysis methods previously developed in R for analysis of SeaFlow flow cytometer data will be ported to the PipeCyte Labview based control software so that the multi-parameter flow cytometer data can be reduced to phytoplankton population counts in realtime. This reduced data set along with GPS fix will be transmitted back to ship and shore by satellite modem. The proposed buoy-deployed instrument will be powered by four 100 W-hr lithium batteries to yield instrument on-time of approximately 50 hours per deployment. Final field testing to demonstrate proof-of-concept will occur in the sub-tropic Pacific Ocean where real-time counts of Prochlorococcus, Synechococcus and small eukaryotic phytoplankton will be broadcast to the ship.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.