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Studies & Validations

Studies & Validations

  • Mobil-O-Graph® - Invasive comparison studies
  • Mobil-O-Graph® - Non-invasive comparison studies
  • Tel-O-Graph®
  • AF®-Logic (Auto-Feedback-Logic)

Mobil-O-Graph® - Invasive comparison studies

PWV invasive

PWV invasive
Blood Press Monit. 2013 Jun;18(3):173-6. doi: 10.1097/MBP.0b013e3283614168.

Oscillometric estimation of aortic pulse wave velocity: comparison with intra-aortic catheter measurements.
Hametner B, Wassertheurer S, Kropf J, Mayer C, Eber B, Weber T
Department of Health and Environment, AIT Austrian Institute of Technology, Vienna, Austria.

Abstract:

OBJECTIVES:
Recently, a novel method to estimate aortic pulse wave velocity (aPWV) noninvasively from an oscillometric single brachial cuff waveform reading has been introduced. We investigated whether this new approach provides acceptable estimates of aPWV compared with intra-aortic catheter measurements.
 
METHODS:
Estimated values of aPWV obtained from brachial cuff readings were compared with those obtained using an intra-aortic catheter in 120 patients (mean age 61.8±10.8 years) suspected for coronary artery disease undergoing cardiac catheterization. Differences between aPWV values obtained from the test device and those obtained from catheter measurements were estimated using Bland-Altman analysis.
 
RESULTS:
The mean difference±SD between brachial cuff-derived values and intra-aortic values was 0.43±1.24 m/s. Comparison of aPWV measured by the two methods showed a significant linear correlation (Pearson's R=0.81, P<0.0001). The mean difference for repeated oscillometric measurements of aPWV was 0.05 m/s, with 95% confidence interval limits from -0.47 to 0.57 m/s.
 
CONCLUSION:
a PWV can be obtained using an oscillometric device with brachial cuffs with acceptable accuracy compared with intra-aortic readings.
 
Central BP invasive / non-invasive

Central BP invasive / non-invasive
Hypertension. 2011 Nov;58(5):825-32. doi: 10.1161 / HYPERTENSION
AHA.111.176313.
Epub 2011 Sep 12.

Validation of a brachial cuff-based method for estimating central systolic blood pressure.
Weber T, Wassertheurer S, Rammer M, Maurer E, Hametner B, Mayer CC, Kropf J, Eber B
Cardiology Department, Klinikum Wels

Abstract:

The prognostic value of central systolic blood pressure has been established recently. At present, its noninvasive assessment is limited by the need of dedicated equipment and trained operators. Moreover, ambulatory and home blood pressure monitoring of central pressures are not feasible. An algorithm enabling conventional automated oscillometric blood pressure monitors to assess central systolic pressure could be of value. We compared central systolic pressure, calculated with a transfer-function like method (ARCSolver algorithm), using waveforms recorded with a regular oscillometric cuff suitable for ambulatory measurements, with simultaneous high-fidelity invasive recordings, and with noninvasive estimations using a validated device, operating with radial tonometry and a generalized transfer function. Both studies revealed a good agreement between the oscillometric cuff-based central systolic pressure and the comparator. In the invasive study, composed of 30 patients, mean difference between oscillometric cuff/ARCSolver-based and invasive central systolic pressures was 3.0 mm Hg (SD: 6.0 mm Hg) with invasive calibration of brachial waveforms and -3.0 mm Hg (SD: 9.5 mm Hg) with noninvasive calibration of brachial waveforms. Results were similar when the reference method (radial tonometry/transfer function) was compared with invasive measurements. In the noninvasive study, composed of 111 patients, mean difference between oscillometric cuff/ARCSolver-derived and radial tonometry/transfer function-derived central systolic pressures were -0.5 mm Hg (SD: 4.7 mm Hg). In conclusion, a novel transfer function-like algorithm, using brachial cuff-based waveform recordings, is suited to provide a realistic estimation of central systolic pressure.

 

Comparison of an Oscillometric Method with Cardiac Magnetic Resonance for the Analysis of Aortic Pulse Wave Velocity

Comparison of an Oscillometric Method with Cardiac Magnetic Resonance for the Analysis of Aortic Pulse Wave Velocity
PLOS ONE | DOI: 10.1371/journal.pone.0116862

Hans-Josef Feistritzer1, Sebastian J. Reinstadler1, Gert Klug1, Christian Kremser2, Benjamin Seidner1, Regina Esterhammer2, Michael F. Schocke2, Wolfgang-Michael Franz1, Bernhard Metzler1
1 University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria, 2 Department of Radiology I, Medical University of Innsbruck, Innsbruck, Austria

Abstract:

OBJECTIVES:
Pulse wave velocity (PWV) is the proposed gold-standard for the assessment of aortic elasticproperties. The aim of this study was to compare aortic PWV determined by a recently developed oscillometric device with cardiac magnetic resonance imaging (CMR).
 
METHODS:
PWV was assessed in 40 volunteers with two different methods. The oscillometric method (PWVOSC) is based on a transfer function from the brachial pressure waves determined by oscillometric blood pressure measurements with a common cuff (Mobil-O-Graph, I.E.M. Stolberg, Germany). CMR was used to determine aortic PWVCMR with the use of the transit time method based on phase-contrast imaging at the level of the ascending and abdominal aorta on a clinical 1.5 Tesla scanner (Siemens, Erlangen, Germany).
 
RESULTS:
The median age of the study population was 34 years (IQR: 24–55 years, 11 females). A very strong correlation was found between PWVOSC and PWVCMR (r = 0.859, p < 0.001). Mean PWVOSC was 6.7 ± 1.8 m/s and mean PWVCMR was 6.1 ± 1.8 m/s (p < 0.001). Analysis of agreement between the two measurements using Bland-Altman method showed a bias of 0.57 m/s (upper and lower limit of agreement: 2.49 m/s and -1.34 m/s). The corresponding coefficient of variation between both measurements was 15%.
 
CONCLUSION:
Aortic pulse wave velocity assessed by transformation of the brachial pressure waveform showed an acceptable agreement with the CMR-derived transit time method.
 
Comparison of invasive and brachial cuff-based noninvasive measurements for the assessment of blood pressure amplification

Comparison of invasive and brachial cuff-based noninvasive measurements for the assessment of blood pressure amplification
Hypertens Res. 2017 Mar;40(3):237-242. doi:10.1038/hr.2016.132. Epub 2016 Oct 20.

Nakagomi A, Okada S, Shoji T, Kobayashi Y.
Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, Chiba, Japan.

Abstract:

Our aim was to assess the discrepancy in the blood pressure amplification (BPA) value defined as the aortic-to-brachial increase in systolic BP (SBP) between invasive and noninvasive brachial cuff-based methods. In 45 patients undergoing cardiac catheterization, BP in the brachial artery and ascending aorta were measured with an invasive catheter and a brachial cuff-based oscillometric device. To calculate aortic SBP, brachial waveforms were calibrated by the brachial systolic and diastolic BP (DBP) (C1 calibration) or by the brachial mean BP and DBP (C2 calibration). C1 calibration underestimated aortic SBP (-17.7 mm Hg (95% confidence interval: -21.9 to -13.5)), whereas C2 calibration generated an approximately accurate aortic SBP (1.8 mm Hg (-2.4 to 5.9)). Regarding brachial SBP, noninvasively measured values were markedly underestimated (22.2 mm Hg (-26.4 to -18.0)), resulting in a slightly low BPA value in C1 calibration (11.9±6.3 mm Hg) and a paradoxical negative BPA value in C2 calibration (-7.6±6.7 mm Hg). Multiple linear regression analysis showed that the cuff-catheter difference of BPA was positively correlated with the cuff-catheter difference of brachial SBP in both calibrations (C1 calibration: β=0.51; C2 calibration: β=0.50; both P<0.01). Although noninvasively measured BPA was associated with invasively measured BPA only in C1 calibration (r=0.33, P=0.03), when using invasively measured brachial SBP instead of a cuff-based measurement, the BPA was well associated with invasively measured BPA in both calibrations (C1 calibration: r=0.57; C2 calibration: r=0.52; both P<0.001). In conclusion, there was a trade-off in accuracy between brachial cuff-based noninvasive aortic SBP and BPA because of the inherent inaccuracies in the cuff-based method. This finding should be fully considered in establishing standardized reference values for aortic BP.

Modeling arterial and left ventricular coupling for non-invasive measurements

Modeling arterial and left ventricular coupling for non-invasive measurements
Simulation Modelling Practice and Theory, Volume 16, Issue 8, September 2008, Pages 988-997

Siegfried Wassertheurer, Christoph Mayer, Felix Breitenecker
Elsevier Science B.V., Amsterdam; 2008

Abstract:

The aim of the presented work has been the development of an algorithm for a non-invasive, portable, easy-to-use, and affordable device for measuring systemic cardiovascular parameters such as cardiac output and peripheral resistance. The data acquisition is based on a common oscillometric measurement using an occlusive blood pressure cuff, and no additional calibration is necessary. The novel algorithm introduced here combines several simulation techniques like neural networks or differential equations, which will be explained briefly. The determination of the hemodynamical parameters is based on the idea that the ejection work of the left ventricle is subject to an optimization principle. This kind of model needs no additional external calibration and opens therefore good perspectives for non-expert use in cardiovascular risk stratification and hypertension therapy optimization. To verify the approach we present some clinical results and a relevant discussion on it, followed by a view of future work.


Mobil-O-Graph® - Non-invasive comparison studies

Central BP non-invasive

Central BP non-invasive
Blood Press Monitoring 2012 Jun;17(3):128-31
10.1097/MBP.0b013e328353ff63.

Oscillometric estimation of central blood pressure: validation of the comparison with the SphygmoCor device.
Weiss W, Gohlisch C, Harsch-Gladisch C, Tölle M, Zidek W, van der Giet M
Med. Klinik mit Schwerpunkt Nephrologie, Charité

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.
 
CONCLUSION:
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.


Source: https://www.ncbi.nlm.nih.gov/pubmed/22561735, 16.06.2017

Aix – non-invasive

Aix – non-invasive
J Hum Hypertens. 2010 Aug;24(8):498-504. doi: 10.1038/jhh.2010.27. Epub 2010 Mar 18.

A new oscillometric method for pulse wave analysis: comparison with a commontonometric method.
Wassertheurer S, Kropf J, Weber T, van der Giet M, Baulmann J, Ammer M, Hametner B, Mayer CC, Eber B, Magometschnigg D
Health and Environment, Austrian Institute of Technology, Vienna, Austria

Abstract:

In the European Society of Cardiology-European Society of Hypertension guidelines of the year 2007, the consequences of arterial stiffness and wave reflection on cardiovascular mortality have a major role. But the investigators claimed the poor availability of devices/methods providing easy and widely suitable measuring of arterial wall stiffness or their surrogates like augmentation index (AIx) or aortic systolic blood pressure (aSBP). The aim of this study was the validation of a novel method determining AIx and aSBP based on an oscillometric method using a common cuff (ARCSolver) against a validated tonometric system (SphygmoCor). aSBP and AIx measured with the SphygmoCor and ARCSolver method were compared for 302 subjects. The mean age was 56 years with an s.d. of 20 years. At least two iterations were performed in each session. This resulted in 749 measurements. For aSBP the mean difference was -0.1 mm Hg with an s.d. of 3.1 mm Hg. The mean difference for AIx was 1.2% with an s.d. of 7.9%. There was no significant difference in reproducibility of AIx for both methods. The variation estimate of inter- and intraobserver measurements was 6.3% for ARCSolver and 7.5% for SphygmoCor. The ARCSolver method is a novel method determining AIx and aSBP based on an oscillometric system with a cuff. The results agree with common accepted tonometric measurements. Its application is easy and for widespread use.

Source: https://www.ncbi.nlm.nih.gov/pubmed/?term=A+new+oscillometric+method+for+pulse+wave+analysis%3A+comparison+with+a+commontonometric+method. 16.06.2017

Clinical Validation endpointdata

Clinical Validation endpointdata
Hypertension. 2012 Aug;60(2):534-41. doi: 10.1161
HYPERTENSIONAHA.112.194571.
Epub 2012 May 14.

Wave reflections, assessed with a novel method for pulse wave separation, are associated with end-organ damage and clinical outcomes.
Weber T, Wassertheurer S, Rammer, Haiden A, Hametner B, Eber B
Cardiology Department, Klinikum Wels

Abstract:

We recently developed a novel method for assessment of arterial wave reflections (ARCSolver method): based on adopted Windkessel methods, flow curves are estimated from pressure waveforms, and wave separation analysis is performed, yielding the amplitudes of the forward and backward waves. The aim of this study was to investigate their clinical correlates and prognostic impact. In 725 patients (417 men; mean age, 64 years) undergoing coronary angiography, we determined wave reflections from radial tonometry and transfer function-derived aortic waveforms using pulse wave analysis, as well as wave separation analysis. Measures of pulsatile arterial function were statistically significant, although moderately associated with markers of cardiac load and subclinic cardiac, renal, and aortic end-organ damage. After a median follow-up duration of 1399 days, 139 patients reached the combined cardiovascular end point (death, myocardial infarction, stroke, coronary, cerebrovascular, and peripheral revascularization). In univariate analysis, the relative risk of the combined end point increased with increasing levels of incident pressure wave height, augmented pressure, and forward and backward wave amplitude (hazard ratio for 1 SD was 1.302, 1.236, 1.226, and 1.276; P<0.01 for all, respectively). In multivariate analysis, backward wave amplitude was the most consistent predictor of the combined end point. Of note, its predictive value was independent of brachial systolic, diastolic, and mean blood pressures and was superior to brachial pulse pressure. In conclusion, the amplitude of the reflected wave, as assessed with a novel method for wave separation, is associated with hypertensive end organ damage and is an independent predictor of cardiovascular events in high-risk patients.

Source: https://www.ncbi.nlm.nih.gov/pubmed/?term=Wave+reflections%2C+assessed+with+a+novel+method+for+pulse+wave+separation%2C+are+associated+with+end-organ+damage+and+clinical+outcomes. 16.06.2017

Assessment of Model Based (Input) Impedance, Pulse Wave Velocity, and Wave Reflection in the Asklepios Cohort

Assessment of Model Based (Input)
Impedance, Pulse Wave Velocity, and Wave
Reflection in the Asklepios Cohort
PLOS ONE | DOI: 10.1371/journal.pone.0141656 October 29, 2015

Hametner B1, Parragh S2, Mayer C1, Weber T3, Van Bortel L4, De Buyzere M4, Segers P5, Rietzschel E6, Wassertheurer S2.
1 Health & Environment Department, AIT Austrian Institute of Technology, Vienna, Austria.
2 Health & Environment Department, AIT Austrian Institute of Technology, Vienna, Austria; Department of Analysis & Scientific Computing, Vienna University of Technology, Vienna, Austria. 3 Cardiology Department, Klinikum Wels-Grieskirchen, Wels, Austria. 4 Department of Pharmacology, Ghent University, Ghent, Belgium. 5 Institute of Biomedical Technology, iMinds Medical IT, Ghent University, Ghent, Belgium. 6 Department of Internal Medicine, Ghent University, Ghent, Belgium.

Abstract:

OBJECTIVES:
Arterial stiffness and wave reflection parameters assessed from both invasive and non-invasive pressure and flow readings are used as surrogates for ventricular and vascular load. They have been reported to predict adverse cardiovascular events, but clinical assessment is laborious and may limit widespread use. This study aims to investigate measures of arterial stiffness and central hemodynamics provided by arterial tonometry alone and in combination with aortic root flows derived by echocardiography against surrogates derived by a mathematical pressure and flow model in a healthy middle-aged cohort.

METHODS:
Measurements of carotid artery tonometry and echocardiography were performed on 2226 ASKLEPIOS study participants and parameters of systemic hemodynamics, arterial stiffness and wave reflection based on pressure and flow were measured. In a second step, the analysis was repeated but echocardiography derived flows were substituted by flows provided by a novel mathematical model. This was followed by a quantitative method comparison.

RESULTS:
All investigated parameters showed a significant association between the methods. Overall agreement was acceptable for all parameters (mean differences: -0.0102 (0.033 SD) mmHg*s/ml for characteristic impedance, 0.36 (4.21 SD) mmHg for forward pressure amplitude, 2.26 (3.51 SD) mmHg for backward pressure amplitude and 0.717 (1.25 SD) m/s for pulse wave velocity).

CONCLUSION:
The results indicate that the use of model-based surrogates in a healthy middle-aged cohort is feasible and deserves further attention.

Source:https://www.ncbi.nlm.nih.gov/pubmed/?term=Assessment+of+Model+Based+(Input)+Impedance%2C+Pulse+Wave+Velocity%2C+and+Wave+Reflection+in+the+Asklepios+Cohort

Wave Separation Analysis

Wave Separation Analysis
Comput Methods Programs Biomed. 2013 Mar;109(3):250-9.
doi: m10.1016/j.cmpb.2012.10.005. Epub 2012 Oct 27

Wave reflection quantification based on pressure comparison, and clinical covariates.
Hametner B, Wassertheurer S, Kropf J, Mayer C, Holzinger A, Eber B, Weber T
Health & Environment Department, AIT Austrian Institute of Technology, Vienna, Austria.

Abstract:

Within the last decade the quantification of pulse wave reflections mainly focused on measures of central aortic systolic pressure and its augmentation through reflections based on pulse wave analysis (PWA). A complementary approach is the wave separation analysis (WSA), which quantifies the total amount of arterial wave reflection considering both aortic pulse and flow waves. The aim of this work is the introduction and comparison of aortic blood flow models for WSA assessment. To evaluate the performance of the proposed modeling approaches (Windkessel, triangular and averaged flow), comparisons against Doppler measurements are made for 148 patients with preserved ejection fraction. Stepwise regression analysis between WSA and PWA parameters are performed to provide determinants of methodological differences. Against Doppler measurement mean difference and standard deviation of the amplitudes of the decomposed forward and backward pressure waves are comparable for Windkessel and averaged flow models. Stepwise regression analysis shows similar determinants between Doppler and Windkessel model only. The results indicate that the Windkessel method provides accurate estimates of wave reflection in subjects with preserved ejection fraction. The comparison with waveforms derived from Doppler ultrasound as well as recently proposed simple triangular and averaged flow waves showed that this approach may reduce variability and provide realistic results.

Source: https://www.ncbi.nlm.nih.gov/pubmed/?term=Wave+reflection+quantification+based+on+pressure+comparison%2C+and+clinical+covariates. 16.06.2017

Reproducibility

Reproducibility
Int J Cardiol. 2013 Sep 8. pii: S0167-5273(13)01662-8. doi: 10.1016.

Non-invasive 24hour ambulatory monitoring of aortic wave reflection and arterial stiffness by a novel oscillometric device: The first feasibility and reproducibility study.
Papaioannou TG, Argyris A, Protogerou AD, Vrachatis D, Nasothimiou EG, Sfikakis PP, Cardiovascular Research Laboratory and Hypertension Center, 1st University Dept. of Propaedeutic Medicine, "Laiko" Hospital, Athens, Greece

Abstract:

BACKGROUND:
Surrogates of aortic wave reflection and arterial stiffness, such as augmentation index (AIx), augmentation pressure, pulse wave velocity (PWV) and pulse pressure amplification (PPampl) are independent predictors of cardiovascular risk. A novel ambulatory, brachial cuff-based oscillometric device has been recently developed and validated, yielding 24-h assessment of the aforementioned parameters (Mobilo-O-Graph). Aim of this study was to investigate the feasibility and reproducibility of wave reflection and arterial stiffness estimation by pulse wave analysis using this device.
 
METHODS:
Thirty treated or untreated hypertensives (mean age: 53.6 ± 11.6 years, 17 men) had test-retest 24-h monitoring one week apart using the test device.
 
RESULTS:
Mean numbers of valid aortic readings per subject, between test and retest, were comparable. Approximately 12 aortic readings per subject (17%) were not feasible or valid. No differences were observed for any 24-h parameter between the two assessments. Bland-Altman plots showed no systemic difference, while the limits of agreement for each parameter indicated high reproducibility (AIx: -7.2 to 8.2%, AP: -3.7 to 4.1mm Hg, PWV: -0.39 to 0.41 m/s, PPampl: -0.08 to 0.06). This was further verified by intraclass correlation coefficients which were >0.8 for each parameter.
 
CONCLUSIONS:
Non-invasive 24-h estimation of wave reflection and arterial stiffness indices, derived by the test device, appear to be highly reproducible. Future studies should investigate whether these measurements have additive prognostic value for cardiovascular risk stratification, beyond common brachial blood pressure measurements or single estimations of wave reflection and PWV at office settings.
24h PWV / Central BP / Aix

24h PWV / Central BP / Aix
Hypertens Res. 2012 Oct;35(10):980-7 doi: 10.1038/hr.2012.78. Epub 2012 May 24

24-h ambulatory recording of aortic pulse wave velocity and central systolic augmentation: a feasibility study.
Luzardo L, Lujambio I, Sottolano M, da Rosa A, Thijs L, Noboa O, Staessen JA, Boggia J.
Unidad de Hipertensión Arterial and Centro de Nefrología, Hospital de Clínicas, Universidad
de la República, Montevideo, Uruguay.

Abstract:

We assessed the feasibility of ambulatory pulse wave analysis by comparing this approach with an established tonometric technique. We investigated 35 volunteers (45.6 years; 51.0% women) exclusively at rest (R study) and 83 volunteers (49.9 years; 61.4% women) at rest and during daytime (1000-2000 h) ambulatory monitoring (R+A study). We recorded central systolic (cSP), diastolic (cDP) and pulse (cPP) pressures, augmentation index (cAI) and pulse wave velocity (PWV) by brachial oscillometry (Mobil-O-Graph 24h PWA Monitor) and radial tonometry (SphygmoCor). We applied the Bland and Altman's statistics. In the R study, tonometric and oscillometric estimates of cSP (105.6 vs. 106.9 mm Hg), cDP (74.6 vs. 74.7 mm Hg), cPP (31.0 vs. 32.1 mm Hg), cAI (21.1 vs. 20.6%) and PWV (7.3 vs. 7.0 m s(-1)) were similar (P0.11). In the R+A study, tonometric vs. oscillometric assessment yielded similar values for cSP (115.4 vs. 113.9 mm Hg; P=0.19) and cAI (26.5 vs. 25.3%; P=0.54), but lower cDP (77.8 vs. 81.9 mm Hg; P<0.0001), so that cPP was higher (37.6 vs. 32.1 mm Hg; P<0.0001). PWV (7.9 vs. 7.4 m s(-1)) was higher (P=0.0002) on tonometric assessment. The differences between tonometric and oscillometric estimates increased (P0.004) with cSP (r=0.37), cAI (r=0.39) and PWV (r=0.39), but not (P0.17) with cDP (r=0.15) or cPP (r=0.13). Irrespective of measurement conditions, brachial oscillometry compared with an established tonometric method provided similar estimates for cSP and systolic augmentation, but slightly underestimated PWV. Pending further validation, ambulatory assessment of central hemodynamic variables is feasible.

Source: https://www.ncbi.nlm.nih.gov/pubmed/?term=24-h+ambulatory+recording+of+aortic+pulse+wave+velocity+and+central+systolic+augmentation%3A+a+feasibility+study. 16.06.2017

24h Central BP

24h Central BP
Am J Hypertens. 2012 Aug;25(8):876-82. doi: 10.1038/ajh.2012.63. Epub 2012 Jun 7.

Feasibility and reproducibility of noninvasive 24 h ambulatory aortic blood pressure monitoring with a brachial cuff-based oscillometric device.
Protogerou AD, Argyris A, Nasothimiou E, Vrachatis D, Papaioannou TG, Tzamouranis D, Blacher J, Safar ME, Sfikakis P, Stergiou GS
Hypertension Center and Cardiovascular Research Laboratory, 1st Department of Propaedeutic Medicine, Laiko Hospital, National and Kapodistrian University of Athens, Athens, Greece.

Abstract:

BACKGROUND:
Accumulating evidence suggests the potential superiority of office aortic blood pressure (BP) over brachial in the management of arterial hypertension. The noninvasive aortic 24-h ambulatory brachial BP monitoring (ABPM) is potentially the optimal method for assessing BP profile. The objective of the present study was to investigate the feasibility and reproducibility to perform noninvasively 24-h aortic ABPM with a novel validated brachial cuff-based automatic oscillometric device (Mobilo-O-Graph) which records brachial BP and waveforms and assesses aortic BP via mathematical transformation.
 
METHODS:
Thirty consecutive subjects (mean age: 53.6 ± 11.6 years, 17 men) had a test-retest ABPM with at least 1-week interval. No modification of vasoactive drug treatment during the interval was allowed while similar 24-h activity during both recording days was recommended.
 
RESULTS:
The average number of valid readings for brachial vs. aortic BP were 69.9 ± 10.4 vs. 58.0 ± 13.3 in the initial 24-h assessment (P < 0.001) and 68.3 ± 10.8 vs. 56.4 ± 13.6 in the repeat assessment (P < 0.001). No differences in average 24 h aortic BP values were observed between the two assessments (systolic blood pressure (SBP) 115.9 ± 7.7 vs. 115.1 ± 6.0 mm Hg, respectively, P = 0.48, and diastolic 79.7 ± 7.4 vs. 79.2 ± 8.7, P = 0.54). Reproducibility indices of aortic pressure including, intraclass coefficient of variation (SBP: 0.80 (95% confidence interval 0.58-0.90); diastolic: 0.92 (0.83-0.96)) and s.d. of differences (SBP/diastolic: 6.0/4.5 mm Hg) indicated acceptable reproducibility. The Bland-Altman plots indicated no evidence of systemic bias.
 
CONCLUSIONS:
In conclusion, these data suggest that noninvasive 24-h ABPM is feasible and provides reproducible values. Future studies should validate the prognostic ability of 24-h aortic hemodynamics.
 

 

Peripheral BP – ESH Validation

Peripheral BP – ESH Validation
Blood Press Monitoring 2010 Aug;15(4):229-31

Evaluation of the Mobil-O-Graph new generation ABPM device using the ESH criteria.
Franssen PM, Imholz BP
Department of Internal Medicine, Radboud University Nijmegen Medical Centre, The Netherlands, Twee Steden Ziekenhuis, Waalwijk, The Netherlands

Abstract:

We report on the validation of the new generation Mobil-O-Graph 24/48 h ambulatory blood pressure monitor according to the criteria of the European Society of Hypertension. In 15 individuals participating in phase I for systolic pressure, all 45 measures differed less than 15 mmHg, 43 and 33 out of 45 differed less than 10 and 5 mmHg. As for diastolic pressures, even better scores were reached when the device passed the EHS score. In phase II, data were collected in an additional 18 individuals leaving a total of 33 individuals and 99 measures. The phase counts the achieved percentages of two or three measures per individual within 15, 10 and 5 mmHg limits. Systolic pressures exceeded the required 95, 80 and 65% for 15, 10 and 5 mmHg differences with values of 98, 94 and 71%, respectively. As again for diastolic pressure the values were even better, the device passed phase II also. Thus, all phases of the European Society of Hypertension procedure were passed and the results of this study can recommend the use of the Mobil-O-Graph new generation ambulatory blood pressure monitor device in clinical practice.

Source: https://www.ncbi.nlm.nih.gov/pubmed/?term=Evaluation+of+the+Mobil-O-Graph+new+generation+ABPM+device+using+the+ESH+criteria. 16.06.2017

 

Peripheral BP – BHS Validation A/A

Peripheral BP – BHS Validation A/A
Blood Press Monitoring, 2010 Aug;15(4):225-8.
doi:10.1097/MBP.0b013e328338892f.

Validation of the Mobil-O-Graph: 24 h – blood pressure measurement device
Wei W, Tölle M, Zidek W, van der Giet M
Department of Nephrology, Medizinische Klinik IV, Berlin, Germany.

Abstract:

OBJECTIVE:
Twenty-four-hour blood pressure measurement is of importance not only in the detection of hypertension but also in the detection of blood pressure changes in hypertensive and nonhypertensives over the day to identify, for example, nondipper hypertensives. This study describes the validation of the mobil-O-Graph according to the criteria of the British Hypertension Society (BHS).

METHODS:
For each patient three readings obtained by the mobil-O-Graph were compared with auscultatory sphygmomanometric readings obtained by two trained clinicians. The sphygmomanometric reference measurements were alternated with the readings obtained by the device. Eighty-five patients (mean age 53.4+/-18.4 years) were recruited for the BHS protocol. Differences between blood pressure values of the test device and the mercury reading were calculated for each measurement.

RESULTS:
In the BHS validation procedure the mean differences of the observer readings and the test device were -2.2+/-6.7 (systolic) and -0.6+/-5.6 mmHg (diastolic) for observer 1 and -2.2+/-7.3 mmHg (systolic) and-0.4+/-6.1 mmHg (diastolic) for observer 2. The device achieved grade A for systolic and diastolic blood pressure for both the observers 1 and 2 leading to a final grade A/A. According to the BHS protocol the measurements of the device have to be considered 'very accurate and with no error of clinical relevance'.

CONCLUSION:
The device met the accuracy requirements of the BHS standard and can be recommended for clinical use.

Source: https://www.ncbi.nlm.nih.gov/pubmed/20216407, 16.06.2017

 

Relationship between Central BP and left ventricular mass

Relationship between Central BP and left ventricular mass
Hypertension. 2017 Dec;70(6):1157-1164
doi: 10.1161/HYPERTENSIONAHA.117.09917. Epub 2017 Oct 23

Relationship Between 24-Hour Ambulatory Central Systolic Blood Pressure and Left Ventricular Mass: A Prospective Multicenter Study.
Weber T, Wassertheurer S, Schmidt-Trucksäss A, Rodilla E, Ablasser C, Jankowski P, Lorenza Muiesan M, Giannattasio C, Mang C, Wilkinson I, Kellermair J, Hametner B, Pascual JM, Zweiker R, Czarnecka D, Paini A, Salvetti M, Maloberti A, McEniery C.A
Cardiology Department, Klinikum Wels-Grieskirchen, Austria

Abstract:

We investigated the relationship between left ventricular mass and brachial office as well as brachial and central ambulatory systolic blood pressure in 7 European centers. Central systolic pressure was measured with a validated oscillometric device, using a transfer function, and mean/diastolic pressure calibration. M-mode images were obtained by echocardiography, and left ventricular mass was determined by one single reader blinded to blood pressure. We studied 289 participants (137 women) free from antihypertensive drugs (mean age: 50.8 years). Mean office blood pressure was 145/88 mm Hg and mean brachial and central ambulatory systolic pressures were 127 and 128 mm Hg, respectively. Mean left ventricular mass was 93.3 kg/m2, and 25.6% had left ventricular hypertrophy. The correlation coefficient between left ventricular mass and brachial office, brachial ambulatory, and central ambulatory systolic pressure was 0.29, 0.41, and 0.47, respectively (P=0.003 for comparison between brachial office and central ambulatory systolic pressure and 0.32 for comparison between brachial and central ambulatory systolic pressure). The results were consistent for men and women, and young and old participants. The areas under the curve for prediction of left ventricular hypertrophy were 0.618, 0.635, and 0.666 for brachial office, brachial, and central ambulatory systolic pressure, respectively (P=0.03 for comparison between brachial and central ambulatory systolic pressure). In younger participants, central ambulatory systolic pressure was superior to both other measurements. Central ambulatory systolic pressure, measured with an oscillometric cuff, shows a strong trend toward a closer association with left ventricular mass and hypertrophy than brachial office/ambulatory systolic pressure.

Source: https://www.ncbi.nlm.nih.gov/pubmed/29061725

 


Tel-O-Graph®

Peripheral BP – BHS Validation A/A

Peripheral BP – BHS Validation A/A
Blood Press Monitoring, 2016 Apr; 19. doi:10.1097/MBP.0000000000000195

Validation of the Tel-O-GRAPH, a new oscillometric blood pressure-measuring device, according to the British Hypertension Society protocol.
Reshetnik A, Gohlisch C, Zidek W, Tölle M, van der Giet M.
Department of Nephrology, Charité- Campus Benjamin Franklin, Berlin, Germany

Abstract:

OBJECTIVE:
Hypertension is a major cardiovascular risk factor. Therefore, the accuracy of blood pressure (BP) measurement with self-measuring devices is of fundamental importance. Consequently, emerging BP devices should be evaluated against the gold standard according to an established and proven protocol.
 
METHODS:
Tel-O-GRAPH, a new oscillometric self-measuring device of brachial BP, was evaluated against auscultatory sphygmomanometry according to the BHS protocol. Bland-Altman plots were completed for systolic (SBP) and diastolic blood pressures (DBP), and the mean differences and SDs between the test device and the reference device were computed for all BP values.
 
RESULTS:
A total of 85 individuals (mean age 48.11±18.0 years; 61% men) were included after they provided informed consent. Overall, 510 measurements were performed. The mean device-observer difference was -0.2±6.6 for SBP and 0.2±6.6 for DBP. The device achieved grade A for SBP and DBP for both observers. Examination of the different BP ranges indicated grade B for SBP more than 160 mmHg and grade A for all BP ranges.
 
CONCLUSION:
Tel-O-GRAPH fulfilled the accuracy requirements of the BHS with the highest accuracy level (A) and can thus be used reliably in the oscillometric measurement of the brachial BP.
 
Validation cSBP – Comparison Tel-O-Graph / Sphygmogcor

Validation cSBP – Comparison Tel-O-Graph / Sphygmogcor
J Hum Hypertens. 2016 Dec;30(12):737-741. doi: 10.1038/jhh.2016.21. Epub 2016 Apr 28.

Central blood pressure assessment using oscillometry is feasible for everyday clinical practice.
Reshetnik A, Gohlisch C, Zidek W, Tölle M, van der Giet M.
Department of Nephrology and Transplantation, Charité University Berlin, Campus Benjamin Franklin, Berlin, Germany.

Abstract:

The benefit of the central systolic blood pressure (cSBP) has already been recognized, but its general measurement in the everyday routine is still limited mainly because available established non-invasive assessment devices are not suitable for everyday use. In this study, we investigated the performance of an oscillometric device Tel-O-GRAPH for cSBP assessment in terms of suitability for everyday clinical use. One hundred and three patients were prospectively included. cSBP was computed by Tel-O-GRAPH compared with Sphygmocor using applanation tonometry. There was a good agreement between Tel-O-GRAPH and Sphygmocor for cSBP (mean difference±s.d.: -0.3±6.7 mm Hg; Pearson's R=0.95; P<0.0001). Recorded cSBP values in the supine vs seated position and for the experienced vs non-experienced user did not significantly differ (mean cSBPsupine 122.1±13.9 mm Hg vs cSBPseated 120.7±15.7 mmHg; cSBPnon-experienced 120.6±20.5 mm Hg and cSBPexperienced 119.2±19.9 mm Hg). The mean difference of cSBP between supine and seated positions was 1.5±6.8 and -1.4±5.0 mm Hg between experienced and non-experienced users. This study showed good accuracy in assessing cSBP with an oscillometric BP measurement device Tel-O-GRAPH compared with a Sphygmocor. Furthermore, the calculation of cSBP by Tel-O-GRAPH appears to be easy and can be done during the routine brachial BP measurement. Computed cSBP values seem to remain reliable independently of the patient body position and experience of the operator. Consequently, the easiness of utilization and reliability of the device may open the opportunity for its extended use in everyday clinical practice, as well as reliable alternative for clinical studies, making complex applanation tonometry dispensable.
 

AF®-Logic (Auto-Feedback-Logic)

The individualized measuring technique ensures a fast an gentle measurement. In every single measurement of the 24 h period the pump adapts to the patient’s previous systolic blood pressure.
AF®-Logic leads to a significant patient preference*1 for Mobil-O-Graph® NG. High patient acceptance, less discomfort during a 24h ABPM and less sleep disturbances*2 are key criteria for a successful measurement and make a difference, especially for the patient!

*1: A comparison study of brachial blood pressure recorded with Spacelabs 90217A and Mobil-O-Graph NG devices under static and ambulatory conditions
Journal of Human Hypertension advance online publication, 3 March 2016 ( https://www.ncbi.nlm.nih.gov/pubmed/26935286)

*2: Convenience of ambulatory blood pressure monitoring: comparison of different device
Blood Pressure Monitoring 2005, 10:239-242 (https://www.ncbi.nlm.nih.gov/pubmed/16205441)