title: A standardized system for describing flow/pressure relationships in vascular access devices.
abstract: Catheters are usually characterized by length and external diameter only. We developed a system to describe flow-pressure characteristics with a single number, M, patterned after a Reynolds number-friction factor correlation. A simple alignment chart was constructed that can be used to determine M for catheters of regular internal diameter and given length. If tapers, side holes, or integral connectors are present, M can be determined in-vitro with water by measuring pressure drop at various flows. The chart describes flow pressure functions for blood (Hct = 0.41) if M is known. Using this system, any catheter, needle, valve seat, extracorporeal tubing, or vascular graft can be assigned a single number that describes hydrodynamic performance characteristics.
authors.affiliation: Department of Surgery, University of Michigan Medical School, Ann Arbor 48109-0331.
authors.forename: J P
authors.initials: JP
authors.lastname: Montoya
authors.forename: S I
authors.initials: SI
authors.lastname: Merz
authors.forename: R H
authors.initials: RH
authors.lastname: Bartlett
mesh_terms: D002408:Catheters, Indwelling / Q000145:classification*; D004867:Equipment Design; D006801:Humans; D011312:Pressure; D012212:Rheology