Effect of Needle Inner Diameter on Dosing Accuracy of a Micro Diaphragm Pump for Miniaturized Infusion Systems

Zimmermann A, Martin N, Richter M, Fischer G (2026)

Publication Language: English

Publication Type: Conference contribution, Original article

Publication year: 2026

Publisher: IEEE conference proceedings

Event location: SHIFT-Innovation Centre in Erlangen, Germany

URI: https://www.ismt.fau.de/

Abstract

Miniaturized implantable infusion systems require precise, long-term stable drug delivery at low flow rates. Micro
diaphragm pumps are promising candidates due to their compact form factor and low power consumption, but the fluidic resistance imposed by the delivery needle critically constrains achievable dosing accuracy. This paper presents a multi-week continuous-operation study evaluating the influence of needle
inner diameter (ID) – 150 μm, 250 μm, 410 μm, and 1600 μm – on delivered mass per burst and coefficient of variation (CV) of a piezoelectrically actuated micro diaphragm pump (number P291). CV is evaluated on a standardized window of n = 200 steady-state bursts per needle (first 10 run-in bursts excluded)
to ensure comparability across needle variants. Results reveal a monotonically decreasing relationship between needle ID and CV: the 150 μm needle yields CV= 4.9%, while 250 μm, 410 μm, and 1600 μm achieve 1.3%, 1.2%, and 0.7%, respectively. All needles with ID ≥ 250 μm satisfy the ±5% accuracy threshold referenced in infusion pump standard IEC 60601-2-24, establishing 250 μm as the minimum viable diameter for precision microinfusion with this pump. These findings provide quantitative design guidelines for needle selection in implantable microinfusion systems.

Authors with CRIS profile

Anne Zimmermann Professur für Technische Elektronik Georg Fischer Professur für Technische Elektronik

Involved external institutions

Fraunhofer-Einrichtung für Mikrosysteme und Festkörper-Technologien (EMFT) / Fraunhofer Research Institution for Microsystems and Solid State Technologies DE Germany (DE)

How to cite

APA:

Zimmermann, A., Martin, N., Richter, M., & Fischer, G. (2026). Effect of Needle Inner Diameter on Dosing Accuracy of a Micro Diaphragm Pump for Miniaturized Infusion Systems. In Proceedings of the 4th International Conference on Integrated Systems in Medical Technologies - ISMT 2026. SHIFT-Innovation Centre in Erlangen, Germany: IEEE conference proceedings.

MLA:

Zimmermann, Anne, et al. "Effect of Needle Inner Diameter on Dosing Accuracy of a Micro Diaphragm Pump for Miniaturized Infusion Systems." Proceedings of the 4th International Conference on Integrated Systems in Medical Technologies - ISMT 2026, SHIFT-Innovation Centre in Erlangen, Germany IEEE conference proceedings, 2026.

BibTeX: Download