Biomedical Hydraulic Analyzer Assisted by PC for Direct Blood Pressure Catheter-Transducer Systems

MARTINEZ, ROBERTO JAVIER; FELICE, CARMELO JOSÉ; OLIVERA, JUAN MANUEL; VALENTINUZZI, MÁXIMO EUGENIO

Journal of Clinical Engineering

Año: 1995 vol. 20 p. 224 - 229

The catheter transducer system (CTS) used for direct blood pressure measurement can be characterized as a dynamic secon order underdamped system. Its physical dimensions, the material that composes the catheter, the interconnectig tubes, stopcocks and air bubbles trapped in the system, will vary the damping coefficient, the natural frequency and the time and frequency response of the CTS. Thus, the pressure waveform canbe distorted. This paper describes an instrument that analyzes the CTS, applying a sinusoidal wave (swept in frequency) and a step function, both generated in a liquid medium, that is,  it applies hydraulic pressure waves similar to the physiologic reality. Furthermore, it can simulate and deliver physiological and pathological waveforms in order to have a quick CTS evaluation, or to calibrate monitor  pressure. It has an error of +-2.1% within its operating range. This instrument could also find a place in educational, medical and technical activities.