A computerized integrated system for the assessment of central and peripheral chemoreflex sensitivity

The assessment of chemoreflex sensitivity (CRS) is of major importance in studies investigating the adaptation of ventilation to the needs of human body. Increased sensitivity of chemoreceptors to both hypoxia and hypercapnia has recently been shown to be a powerful and independent prognosticator in heart failure (HF) patients, thus highlighting the importance of the assessment of CRS also in the clinical setting. In spite of this, the measurement of CRS is currently limited to the research setting. One possible reason might be the lack of suitable commercial equipments. On the basis of these considerations, we designed a system to carry out a comprehensive assessment of CRS, including both central and peripheral chemoreceptors. The system is based on the integration of different commercial devices and is entirely managed by a custom software written in Matlab language. The main features of our system are: (1) the implementation of standard methods (the Read's rebreathing test, the CO2 single breath test and the transient hypoxia test) suitable for both pathological and healthy subjects, (2) data quality assurance and reduction of subjective judgment in the analysis through advanced analysis procedures and statistical outliers rejection, and (3) full interactive control of every step of the recording and analysis procedures. The system is currently used in our Institution in the assessment of CRS in HF patients, chronic obstructive pulmonary disease patients and healthy subjects. It has proven to be very effective and easy to use even by clinical personnel without a specific background in respiratory function assessment.