02414nas a2200277   4500000000100000000000100001008004100002260001500043653002700058653001800085653001800103653003500121100001600156700002700172700002200199700001800221700002100239700001800260700001800278245007400296856005500370300000900425490000700434520168100441022001402122       2026                            d  c2026-05-2510aBiomedical Engineering10aLab-on-a-chip10amicrofluidics10aTechniques and instrumentation1 aAnkit Kumar1 aShivanand Pattanshetti1 aRushangi D. Patel1 aRashmi Pandey1 aEthan Mahalingam1 aElaheh Rahbar1 aAbhishek Jain00aHemadyne: accordion-inspired perfusion for microphysiological systems  uhttps://www.nature.com/articles/s41467-026-73722-9  a61940 v173 aA crucial factor limiting the physiological relevance, reproducibility and ease of adoption of microphysiological systems is the constrained non-specific design and performance of existing perfusion systems. Inspired by the physics of the accordion music instrument, we have engineered Hemadyne, a standalone mechanical pump with compact footprint that operates without any additional instruments. The pump is paired with a custom-built control algorithm to reproduce clinical waveforms with a 400-millisecond temporal resolution. We show that Hemadyne is able to replicate Doppler ultrasound waveforms of patient hemodynamics with nearly absolute spatiotemporal fidelity. We also demonstrate that Hemadyne surpasses conventional technologies, providing sustainable and stable flow, including transient forward and backward flows, comprising multiple amplitudes and phases within a single period, with high signal-to-noise ratio and fast response times. Next, we show that Hemadyne sustains the long-term culture of primary human endothelial cells in a vessel-chip for up to 60 days. Further, we apply the system to dissect the role of hemodynamic diastolic rest phase as a determinant of endothelial homeostasis, while revealing a differential response to arterial and venous endothelial cells. Finally, we demonstrate that Hemadyne is able to recapitulate the age-associated pathological effect of transient diastolic retrograde flow on arterial endothelial cells, that animal models cannot reproduce. Taken together, our findings indicate that Hemadyne is an enabling technology that improves operational longevity and physiological relevance of microphysiological systems.  a2041-1723