title: Fibre optic sensor for non-invasive monitoring of blood pressure during MRI scanning.
abstract: This report focuses on designing and implementing a non-invasive blood pressure (NIBP) measuring device capable of being used during magnetic resonance imaging (MRI). Based on measuring pulse wave velocity in arterial blood, the device uses the obtained result to estimate diastolic blood pressure. Pulse transit times are measured by two fibre optical accelerometers placed over the chest and carotid artery. The fabricated accelerometer contains two static fibres and a cantilever beam, whose free end is angled at 90 degrees to act as a reflecting surface. Optical fibres are used for both illuminating the surface and receiving the reflected light. When acceleration is applied to the sensor, it causes a deflection in the beam, thereby changing the amount of reflected light. The sensor's output voltage is proportional to the intensity of the reflected light. Tests conducted on the electronics and sensors inside an MRI room during scanning proved that the device is MR- compatible. No artifacts or distortions were detected.
authors.affiliation: University of Oulu, Department of Electrical and Information Engineering, Optoelectronics and Measurement Techniques Laboratory, P.O. Box, 4500 University of Oulu Oulu 90014, Finland. teemu.myllyla@ee.oulu.fi
authors.forename: Teemu S
authors.initials: TS
authors.lastname: Myllylä
authors.forename: Ahmed Abou
authors.initials: AA
authors.lastname: Elseoud
authors.forename: Hannu S S
authors.initials: HS
authors.lastname: Sorvoja
authors.forename: Risto A
authors.initials: RA
authors.lastname: Myllylä
authors.forename: Juha M
authors.initials: JM
authors.lastname: Harja
authors.forename: Juha
authors.initials: J
authors.lastname: Nikkinen
authors.forename: Osmo
authors.initials: O
authors.lastname: Tervonen
authors.forename: Vesa
authors.initials: V
authors.lastname: Kiviniemi
mesh_terms: D001795:Blood Pressure Determination / Q000295:instrumentation*; D006801:Humans; D008279:Magnetic Resonance Imaging; D055100:Optical Fibers; D055620:Optical Phenomena; D014666:Vasomotor System / Q000502:physiology