Affiliations: The Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden
Correspondence:
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Corresponding author: Roger Andersson, M.S.E.E, Department of Biomedical Engineering, Linköping University, SE-581 85, Linköping, Sweden. Tel.: +46 13 22 2472; Fax: +46 13 10 1902; E-mail: Roger.Andersson@imt.liu.se.
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°–36°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.
