Automatic Control System of a Microfluidic Blood Sampler for Quantitative microPET Studies in Small Laboratory Animals

Quantitative microPET imaging provides the capability of performing biochemical and physiological investigations. The collection of multiple blood samples over time is necessary for quantitative analysis. The procedure is challenging because the amount of blood volume is small in rats and mice. To overcome this issue, an automatic blood sampling system was developed using a novel microfluidic chip design to take serial blood samples (<0.25 muL per sample; 18 blood samples in current design) at precise times from rats and mice. In this work, we utilize a National Instruments DAQPad 6507 digital output computer interface to control the sampling on the chip via mini-pneumatic valves. The system provides a user-friendly GUI programmed by LabVIEW to setup the sampling information, which includes mouse ID, tracer selection and sampling volume and time sequences. It can be easily reconfigured to utilize new microfluidic chip designs as well as changes in the sampling protocol. Real-time sampling status and the output of sampling information is continually displayed. Our initial implementation of this design can automatically collect ~0.185 muL blood samples within less than 2 second intervals from a small rodent.