Volumetric measuring principle
The first uses volumetric measuring principles. This method usually needs a significant flow rate and minimum volume for achieving a reasonable accuracy within an acceptable period of time. This limits the ability to quickly check syringe pumps at the lowest flow rates and in critical applications. This creates a potentially inaccurate and time-consuming calibration process.
Distance measuring principle
The second technique is to measure distance that the plunger travels over a pre-determined period of time and use that figure to extrapolate a figure for accept/reject. This technique is usually determined by the manufacturers of the instruments and carries with it a high degree of inaccuracy when adding together the manual method of measuring, the inaccuracy of the ruler and the cross-sectional area of the plunger.
Both of the above methods lack information of the exact volumetric rate distribution over time.
Improving response time and accuracy of infusion pump calibrations
Recognizing some of the flaws in the techniques above, and having talked to several professional working groups that use syringe pump calibration systems, we were excited to begin new research. In these studies we test new sensor technology and techniques that could benefit the response time and accuracy of infusion pump calibrations.
To define the value of this study we identified together with the working groups potential applications in which accurate dosing is a critical process parameter. Below you will find the applications as identified:
Improving response time and accuracy of infusion pump calibrations
Recognizing some of the flaws in the techniques above, and having talked to several professional working groups that use syringe pump calibration systems, we were excited to begin new research. In these studies we test new sensor technology and techniques that could benefit the response time and accuracy of infusion pump calibrations.
To define the value of this study we identified together with the working groups potential applications in which accurate dosing is a critical process parameter. Below you will find the applications as identified:
The use in pediatrics where patients are extra sensitive and vulnerable for wrong medicine dosage.
Medication dosage at low rates where it is difficult to obtain a relative accurate and stable flow.
Medication with a small therapeutic band in which a high accuracy is even more important.
Multi infusion systems where multiple pumps are connected to a single cannula. In these systems the compliance of the used syringes and tubing can cause major errors in the actual dosage.
Low flow Coriolis sensor
We defined the hypothesis that the characteristics of a low flow Coriolis sensor could support the scope to improve the accuracy and response time of calibration systems used to calibrate syringe pumps. We demonstrated the validity of this hypothesis during an in-house study and at a hospital in the Netherlands. The Coriolis principle chosen due to its proven accuracy and long-term stability. Furthermore, due to their small internal volume and little pressure drop these instruments can be used in line to test complex multi-infusion systems.
Surpassing the accuracy and response time
We bench marked the Coriolis sensor technique against an electronic analytical balance in house. Furthermore, we performed a benchmark study against an infusion calibration system at a hospital in the Netherlands.
The results of this study confirmed that the Coriolis sensor techniques can surpass the accuracy and response time of the incumbent measurement principles used in calibration systems.
Need more information?
Are you interested or do you want to learn more about this subject?
Related blog articles
Calibration for flow meters
Flow control valve; which valve to use for your flow meter?
In-line filters for gas flow instruments