title: Investigation of the performance of two types of the Doppler catheter in vitro.
abstract: There is considerable interest in the use of Doppler catheters for measuring coronary flow reserve in humans. Two types are currently available, these being models having side-mounted or tip-mounted transducers. The performance of these catheters was carefully observed in Silastic tubing perfused with blood by a roller pump. Each catheter was used with two types of positioning wire: a rigid wire and a standard J-tip guidewire. Linear regressions of velocity vs. flow rate were performed. Both catheters performed well with the rigid wire (r greater than or equal to 0.992). When used with the J-tip, the end-mounted catheter suffered decreased performance because of positioning difficulties, while the side-mounted catheter performance was within 6% of the ideal. Measurements made with the side-mounted catheter at low flow rates underestimated the expected response for forward flow. Because of the ease of positioning, the side-mounted catheter is judged to be more useful in measuring flow ratios.
authors.affiliation: Department of Medical Physics, University of Wisconsin, Madison.
authors.forename: N J
authors.initials: NJ
authors.lastname: Hangiandreou
authors.forename: E J
authors.initials: EJ
authors.lastname: Toggart
authors.forename: C A
authors.initials: CA
authors.lastname: Mistretta
mesh_terms: D002404:Catheterization; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods