The Influence of Needle Assembly Sliding of the Jetting Dispenser on the Characteristics of Blood Glucose Test Strip

This study investigates the application of the jet dispensing technique for the dispensing of glucose oxidase (GOD) on blood glucose test strips. In this study, the experimental results indicated that the working principle of the jet dispensing valve is based on the collision of the sliding needle assembly with the seat, causing glucose oxidase (GOD) droplets to eject from the nozzle. During the process, the sliding of the needle assembly will have certain amount of friction, leading to a minute change in the weight of GOD droplets. Such small variation in the weight of GOD droplets will in turn affect the accuracy of blood glucose test strip readings. Special grease which varies in weight was coated on the surface of the needle assembly for dispensing investigation. The results showed that coating the needle assembly with 0.02g of grease will make the ejected GOD on the test strip reaction zone form an arch-shaped droplet, completely covering the electrode on the test strip reaction zone and allowing the test strip to have lower standard deviation (STD) as well as coefficient of variation (CV). It has been evidenced in this study that applying a small amount of grease on the surface of the needle assembly can improve the accuracy of blood glucose test strip.