Temperature Compensated Fibre Bragg Grating Pressure Sensor for Ventricular Assist Devices.

Rotary blood pumps may be used as ventricular assist devices (VADs) to support patients with end-stage heart failure-'rotary VADs'. Clinically, rotary VADs are operated at a constant speed which is set manually. Due to inadequate haemodynamic monitoring equipment outside of the hospital setting, device speed remains the same for weeks or months at a time, leaving clinicians in the dark, and patients vulnerable to harmful over- or under-pumping events. Therefore, it would be beneficial to have an implantable sensor which can measure blood pressure at the rotary VAD inlet or outlet and detect the onset of adverse events. In this study, a temperature compensated fibre Bragg grating (FBG) based strain sensor which can be incorporated into a VAD and used for continuous, real-time blood pressure monitoring is investigated. Error in the pressure reading between the developed and reference sensor occurred due to changes in temperature. A generalised linear model was used to compensate for temperature related error between 35-39º. Without temperature compensation, the mean error in the pressure reading over the desired range of -25 to 150 mmHg was approximately ±5 mmHg. The temperature compensated mean error over the same range was less than ±2 mmHg. The compensation technique was effective over a wide range of temperatures and pressures, demonstrating the potential of the sensor for continuous real-time blood pressure monitoring.