title: Oscillometric estimation of central blood pressure:  validation of the Mobil-O-Graph in comparison with the SphygmoCor device.
abstract: BACKGROUND
  Hypertension is a major risk factor for a wide range of cardiovascular diseases and is typically identified by measuring blood pressure (BP) at the brachial artery. Although such a measurement may accurately determine diastolic BP, systolic BP is not reflected accurately. Current noninvasive techniques for assessing central aortic BP require additional recording of an arterial pressure wave using a high-fidelity applanation tonometer. Within one measurement cycle, the Mobil-O-Graph BP device uses brachial oscillometric BP waves for a noninvasive estimation of central BP. We therefore validated the Mobil-O-Graph against the SphygmoCor device, which is widely known as the commonly used approach for a noninvasive estimation of central BP.
  
  
  METHODS
  For each individual, we compared three readings of the central BP values obtained by the Mobil-O-Graph and SphygmoCor device consecutively. One hundred individuals (mean age 56.1 ± 15.4 years) were recruited for measurement.Differences between the central BP values of the test device and the SphygmoCor device were calculated for each measurement.
  
  
  RESULTS
  The mean difference (95% confidence interval) for the estimated central systolic BP between both devices was -0.6 ± 3.7 mmHg. Comparison of the central BP values measured by the two devices showed a statistically significant linear correlation (R=0.91, P<0.0001). The mean between-method difference was 0.50 mmHg for central systolic BP estimation. The intrarater reproducibility between both the devices was also comparable. Bland and Altman analyses showed that the mean differences (95% confidence interval) between repeated measurements were 1.89 (0.42-3.36) mmHg and 1.36 (-0.16 to 2.83) mmHg for the SphygmoCor and the Mobil-O-Graph device, respectively. Thus, neither of these differences was statistically significantly different from 0. The limits of agreement were -16.34 to 19.73 and -15.23 to 17.17 mmHg for the SphygmoCor and the Mobil-O-Graph device, respectively.
  
  
  CONCLUSIONS
  Oscillometric noninvasive estimation of central BP with the Mobil-O-Graph BP device is as effective as using the well-established SphygmoCor applanation tonometry device. In comparison, the Mobil-O-Graph combines the widespread benefits of brachial BP measurement and also provides central BP within one measurement.
authors.affiliation: Med. Klinik mit Schwerpunkt Nephrologie, Charite-Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Weiss
authors.forename: Christopher
authors.initials: C
authors.lastname: Gohlisch
authors.forename: Christl
authors.initials: C
authors.lastname: Harsch-Gladisch
authors.forename: Markus
authors.initials: M
authors.lastname: Tölle
authors.forename: Walter
authors.initials: W
authors.lastname: Zidek
authors.forename: Markus
authors.initials: M
authors.lastname: van der Giet
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009991:Oscillometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D019722:Sphygmomanometers