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Micropumps for Infusion Therapy
Bartels Mikrotechnik GmbH
In medical applications, such as infusion therapy, micropumps can be an attractive alternative to standard pumps due to their size, weight and low ener-gy demand. The micropump mp6-psense with its double actuator configura-tion offers the possibility of an intrinsic flow control. Therefore it can fulfill higher requirements on safety and accuracy under varying conditions as the standard pump mp6. By the controlled loop function the flow can run con-stantly under varying conditions as pressure, viscosity or temperature changes. The mp6-psense will be demonstrated at this years’ ComPaMED exhibition in hall 8a, booth H19.2.
Infusion therapies like for example the continuous dosing of nutrient solution in parenteral diets have high demands on the flow accuracy. Important is the starting behavior and the stable flow during the course of infusion with a minimum of short time fluctuations. The micropump mp6-psense from Bartels Mikrotechnik with intrinsic flow control has been tested for such applications. A clear and simple picture of the general flow rate stability over time can be gained by a trumpet curve analysis. The trumpet curve shows the variations of the mean flow accuracy over specific observation periods. The variations are presented only as maximum and minimum deviations from the overall mean flow within the observation window. The flow performance of the pumps is measured over a time period of 25 hours after a 24 hour stabilizing phase or emptying of half the reservoir according to the definitions of the standard DIN EN 60601-2-24.
Since the flow controlled micropump mp6-psense has a very dynamic behavior stable flow conditions can already be achieved after 10 minutes. Therefore the stabilization phase could be considerably shortened. The trumpet curve analysis over defined time intervals then shows the maximum positive and negative errors, occurring in the time interval. Achievable flow rates of the mp6-psense are 0,5 – 5 ml/min with a flow accuracy of 10%. For a flow rate of 125 ml/h the exemplarily trumpet curve of mp6-psense is shown below. In short observation windows the error of flow is already below 5 %. With increasing intervals it decreases below 1 %. The absolute error is below 2 %.
Looking at the overall complexity, from the pump side, this solution is fully based on a proven, mass produced component. Additional effort is required for the driving electronics but as the signal processing is straightforward the unit keeps its portability and capability of being driven with batteries. Especially in applications where the micropump should be used as a disposable unit while the electronics is being reused, the full potential of this solution comes into play.
Infusion therapies with flow rates below 0,5 ml/min can either be achieved by quasi-continuous pumping, for which small volumes are dosed in defined time intervals. Or a flow controlled micropump with an integrated flow sensor is used which can achieve lower flow rates with higher accuracies. The flow range of such a system is from 60 µl/min to 5 ml/min with 5 % accuracy.
About Bartels Mikrotechnik
Ever since its foundation in 1996 Bartels Mikrotechnik GmbH has been a synonym for great innovative power and microtechnological know-how.
Bartels specializes in innovative applications of micro systems technology (MST) in the branches of classical consumer goods, mechanical engineering and medical technology. Microfluidics, microactuation and micromechanics constitute the company's technological focus. The international activities of Bartels Mikrotechnik subdivide into two business segments: Bartels microEngineering and Bartels microComponents.
Bartels Mikrotechnik at ComPaMED:
Hall 8a, booth H19.2 (IVAM joint pavilion)
Dr. Ulrike Michelsen, email@example.com,