[Non-invasive, continuous, portable blood pressure recording in the sleep laboratory]

The importance of cardiovascular consequences of sleep related breathing disorders implies the need for continuous recording of blood pressure in any cardiorespiratory polysomnography. Invasive techniques, which are the gold standard, are limited to special indications and studies. Non-invasive, continuous methods opened new possibilities for sleep laboratory investigations. The existing Finapres system proved to be a valuable method if parallel video recording was applied. The size of the system restricts its application to stationary settings only. Therefore the methodology was improved and integrated in a portable recorder. A prototype of this recorder, the Portapres, was validated against invasive pressure in 9 one-hour tests during the day and 12 polysomnographic recordings of 8 hours duration. The Portapres has now two finger cuffs and an automatic hydrostatic height compensation to overcome limitations of the Finapres. The technical implementation of the recorder needs more improvements. The correlation of mean blood pressure was 0.81 and mean pressure of the Portapres was 6.8 mmHg lower than invasive values.