Evaluating Seismocardiography as a Non-Exercise Method for Estimating Maximal Oxygen Uptake

The value of maximal oxygen uptake (VO ) is a key health indicator. Usually, VO is determined with cardiopulmonary exercise testing (CPET), which is cumbersome and time-consuming, making it impractical in many testing scenarios. The aim of this study is to validate a novel seismocardiography sensor (Seismofit , VentriJect DK, Hellerup, Denmark) for non-exercise estimation of VO . A cohort of 94 healthy subjects (52% females, 48.2 (8.7) years old) were included in this study. All subjects performed an ergometer CPET. Seismofit measurements were obtained 10 and 5 min before CPET in resting condition and 5 min after exhaustion. The CPET VO was 37.2 (8.6) mL/min/kg, which was not different from the two first Seismofit estimates at 37.5 (8.1) mL/min/kg ( = 0.28) and 37.3 (7.8) mL/min/kg ( = 0.66). Post-exercise Seismofit was 33.8 (7.1) mL/min/kg ( < 0.001). The correlation between the CPET and the Seismofit was r = 0.834 and r = 0.832 for the two first estimates, and the mean average percentage error was 11.4% and 11.2%. Intraclass correlation coefficients between the first and second Seismofit measurement was 0.993, indicating excellent test-retest reliability. The novel Seismofit VO estimate correlates well with CPET VO , and the accuracy is acceptable for general health assessment. The repeatability of Seismofit estimates obtained at rest was very high.