Towards diagnostic flow measurement from a catheter tip pressure sensor

This paper reports the investigation of the additional ability of a catheter tip pressure sensor to measure flow rate. The sensor´s ability to measure flow rate builds on an earlier development of temperature measurement from the pressure sensor. The flow rates of interest range from 0 to 30 mL/hour, those expected through a hydrocephalus shunt. The feasibility of making flow measurements from the MEMS piezoresistive pressure sensor was assessed in terms of the sensor´s repeatability, its potential resolution and its temporal response. Within the flow range 0 to 30 mL/hour the sensor has demonstrated the ability to resolve differences in flow rate of less than 5 mL/hour. The sensor demonstrates high degree of repeatability with coefficient of variation of less than 5 % across all flow rates in the measurement range.