title: An asymmetric dialysis tube as an integrated part of a pressure-monitoring sensor.
abstract: A sensor has been designed consisting of a tube holder with a force transducer and a tube with a modified cross-section. The holder has a lid that encloses the tube. By having a stiff holder and a compliant tube, the idea is that the intraluminal pressure in the tube can be obtained from the measured force. The method is intended for non-invasive pressure measurements in blood or dialysate tubes. We have used a tube cross-sectional geometry where the outer surface is elliptic and the inner surface is circular with a relation of 2:1 between the thinnest and thickest tube sides. The pressure transducer system shows a linear relationship between the applied pressure and the sensor output (r=0.999). Within the temperature range, 32 degrees --36 degrees C, which corresponds to the blood and dialysate temperatures, the sensor accuracy is within +/- 0.8 kPa (+/- 6 mm Hg). This indicates that the sensor should be clinically useful during dialysis and similar applications.
authors.affiliation: The Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden. Roger.Andersson@imt.liu.se
authors.forename: R
authors.initials: R
authors.lastname: Andersson
authors.forename: P
authors.initials: P
authors.lastname: Ask
mesh_terms: D015924:Blood Pressure Monitors; D003956:Dialysis / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011312:Pressure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013696:Temperature; D014481:United States