Comparing the Finapres and Caretaker Systems for Measuring Pulse Transit Time Before and After Exercise

Abstract

We aimed to compare the Finapres system, which is designed for accurate intra-arterial amplitude measurement, to the Caretaker system, which is designed for temporal accuracy of intra-arterial measurement, in regard to measurement of pulse transit time (PTT) at baseline and following an endurance exercise session. Pulse transit time was evaluated between the R-wave of the ECG and the foot of the arterial waveform using either the Finapres (fpPTT) or Caretaker (ctPTT). 23 participants were measured before and after completion of endurance exercise. When comparing PTT values before and after an exercise intervention within devices, ctPTT was significantly different following exercise (P=0.03); however, the Finapres obtained values did not differ significantly. Before exercise, there was no significant relationship between devices, however, after exercise a significant moderate correlation was observed (r=0.45, P=0.02). Significant differences existed between ctPTT and fpPTT (P< 0.001). The Caretaker system appears to be more accurate at detecting changes in PTT occurring as a result of a single aerobic exercise session. This may be due to the servo-controller feedback loop in the waveform contour predicting algorithm within the Finapres system, which is not present in the Caretaker unit. The Finapres system also appears to have an inherent delay in pulse contour reporting.

Continuous blood pressure response at different intensities in leg press exercise

“…A non-invasive, continuous blood pressure monitor would be necessary. The Finapres blood pressure monitor, which has been used in several clinical trials, [16][17][18] offers a continuous and noninvasive blood pressure monitoring similar to intra-arterial technique. 19 In light of these facts, the objective of this study is to continuously evaluate the blood pressure response at different intensities of leg press exercise with the same duration and number of repetitions.…”