title: Development of an MR-compatible, rotation-insensitive, annular pressure sensor.
abstract: There is a growing interest in performing intravascular interventions guided by MR imaging--a technique which offers the possibility of flow measurements during the intervention. For a reliable assessment of the haemodynamic significance of a stenosis, the flow and the pressure decay within the stenosis should both be measured. We have developed an optical, MR-compatible, pressure sensor (Annupres) that uses a novel annular element. Existing optical pressure sensors measure pressures unilaterally, thus giving rise to artefacts because of the dependence of the measurement on the angular orientation of the aperture. The annular element, however, measures blood pressure on all sides, and we show that by using circularly polarized light this pressure measurement is intrinsically insensitive to rotation of the sensor around its long axis. The Annupres sensor has been tested in an experimental set-up, and was able to measure pressures from 50 mmHg to 180 mmHg reliably with an accuracy of 1.5%.
authors.affiliation: Department of Radiology, Image Sciences Institute, University Hospital Utrecht, The Netherlands. m.konings@azu.nl
authors.forename: M K
authors.initials: MK
authors.lastname: Konings
authors.forename: L W
authors.initials: LW
authors.lastname: Bartels
authors.forename: C J
authors.initials: CJ
authors.lastname: Bakker
mesh_terms: D001783:Blood Flow Velocity / Q000528:radiation effects*; D001794:Blood Pressure / Q000528:radiation effects; D006439:Hemodynamics / Q000528:radiation effects; D006801:Humans; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D015233:Models, Statistical; D011312:Pressure; D011878:Radiotherapy / Q000295:instrumentation*; D013997:Time Factors