Remotely accessible demonstrator for dynamic characterization of pressure measurement catheters

In this project an experimental board for the characterization of a catheter for blood pressure measurement was designed and implemented. This system aims to simulate an invasive blood pressure measurement system studying the static and dynamic behavior of this process. This project was thought and made in the laboratory of Instrumentation and Bioengineering of the Electronics Engineering Department in the UPC of Barcelona. We wanted to study the time and frequency response of a pressure's measurement system using catheters. The idea is to see the static and dynamic comportment of this system introducing catheters with air, liquid or liquid with bubbles to find out the response. The static behavior was simulated with a stepper linear motor to verify the linearity of the system, instead the dynamic behavior was simulated with an inductive linear motor that produces an impulsive stimulus like the heartbeat. The joint heartbeat-catheter system produces a damped second order response, of which is possible to study the damping factor and the oscillation frequency. This response can be modeled with an R-L-C circuit and the idea is to create a multiple catheter-sensor's system to find out the frequency response and trying to study the different returns with air, water and water with bubbles, to extract different behaviors with the damping introduced by the air. At the end of each catheter we have put a piezoresistive sensor to obtain the transitory response, conditioned by an instrumentation amplifier for each sensor. Measurements are made with an experimental board that permits to derive measures with remote connection and to drive motors using a clock signal got from the board and a driving software. This board is used to permit to remotely connect an user at a defined server for verifying measurement results from his computer for didactical purposes