Noninvasive vascular diagnostic testing: Techniques and clinical applications

Yao, James S.T.; Flinn, William R.; Bergan, John J.

doi:10.1016/0033-0620(84)90013-6

“…In all of the data analyzed, this algorithm was able to determine a value for T 1 in all of the waves. The triangular approximation is consistent with the general aortic flow envelope obtained from Doppler ultrasound 25 or electromagnetic 19,26 flow measurements. Furthermore, the timing of peak flow corresponds with the time of early systolic inflection in the aortic pressure wave.…”

Section: Analytical Treatmentsupporting

confidence: 77%

Determination of Aortic Pulse Wave Velocity From Waveform Decomposition of the Central Aortic Pressure Pulse

Qasem

¹

,

Avolio

²

2008

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Abstract-Aortic pulse wave velocity (PWV), calculated from pulse transit time (PTT) using 2 separate pulse recordings over a known distance, is a significant biomarker of cardiovascular risk. This study evaluates a novel method of determining PTT from waveform decomposition of central aortic pressure using a single pulse measurement. Aortic pressure was estimated from a transformed radial pulse and decomposed into forward and backward waves using a triangular flow wave. Pulse transit time was determined from cross-correlation of forward and backward waves. Pulse transit time, representing twice the PTT between 2 specific sites, was compared with independent measurements of carotid-femoral PTT in a cohort of 46 subjects (23 females; age 57Ϯ14 years). Linear regression between measured PTT (y; milliseconds) and calculated PTT (x; milliseconds) was yϭ1.05xϪ2. Key Words: pulse Ⅲ aorta Ⅲ arterial pressure Ⅲ digital signal processing Ⅲ blood flow P ulse wave velocity (PWV) has become a well-accepted surrogate measure of arterial stiffness 1-5 and has been shown to be a significant predictor of cardiovascular risk in diseased 2,4 and older healthy populations. 6 Aortic PWV is determined noninvasively by measuring the pulse transit time (PTT) over a known distance of the aortic trunk. Although in some studies the arterial pulse has been detected using Doppler ultrasound probes in the aortic arch or subclavian artery and the femoral artery, 7,8 the general convention is to register the pressure pulse using some form of mechanical transducer. 9 The carotid and femoral pulses are either recorded simultaneously (as in the Complior device, Artech Medical 10,11 ) or recorded sequentially using a single probe and the carotid-femoral PTT determined with reference to the R wave of the ECG signal (as in the SphygmoCor device, AtCor Medical 11-13 ). Both methods have been shown to be comparable in detecting similar relative changes in PTT with interventions. 11 Although these methods are useful in research and clinical laboratories, there is increasing interest in attempts at simplifying the procedure for routine clinical measurements in terms of eliminating the necessary intrusion of recording the femoral pulse or when a reliable femoral recording cannot be readily obtained, as can often occur in obese subjects or those with excessive abdominal adipose tissue. Attempts at providing a less intrusive methodology have resulted in determination of parameters related to PTT from recording of a single pulse trace, such as the use of the second derivative of the finger photoplethysmogram. 14 Although of limited use, this method has not shown a strong association with PWV. 14,15 In this present study, we propose a novel noninvasive and less intrusive method to assess arterial stiffness from a single peripheral pulse waveform. This method determines carotidto-femoral PTT from the radial pressure waveform, which is transformed to derive the central aortic pressure waveform via a validated transfer function. 12,16 -18 The central aortic pr...

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“…Nowadays, toe blood pressure is usually measured by either strain gauge 11 or photoplethysmography (PPG). 12 Both methods can be used in the alternating current (AC) and direct current (DC) mode. In the AC mode the resumption of blood is detected by the return of the pulsatile signal, which is reduced, or even absent, in patients with multiple occlusions as in patients with critical leg ischemia.…”

mentioning

confidence: 99%

The usefulness of a laser Doppler in the measurement of toe blood pressures

Ubbink¹,

Legemate²,

Haan³

et al. 2000

Journal of Vascular Surgery

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“…A triangular shape of the aortic flow wave is a reasonable assumption because the triangular approximation is consistent with the general aortic flow envelope obtained from Doppler ultrasound [30] or electromagnetic [29] flow measurements. In 2006, Westerhof et al [29] provided a novel method for separating the measured aortic pressure wave into its forward and backward components on the basis of a single aortic pressure pulse and an assumed triangular flow.…”

Section: Discussionmentioning

confidence: 65%

Quantification of cardiac pumping mechanics in rats by using the elastance–resistance model based solely on the measured left ventricular pressure and cardiac output

Wang

¹

,

Chang

²

,

Wu

³

et al. 2019

Pflugers Arch - Eur J Physiol

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The cardiac pumping mechanics can be characterized by both the maximal systolic elastance ( E max ) and theoretical maximum flow ( Q max ), which are generated using an elastance–resistance model. The signals required to fit the elastance–resistance model are the simultaneously recorded left ventricular (LV) pressure and aortic flow ( Q m ), followed by the isovolumic LV pressure. In this study, we evaluated a single-beat estimation technique for determining the E max and Q max by using the elastance–resistance model based solely on the measured LV pressure and cardiac output. The isovolumic LV pressure was estimated from the measured LV pressure by using a non-linear least-squares approximation technique. The measured Q m was approximated by an unknown triangular flow ( Q tri ), which was generated by using a fourth-order derivative of the LV pressure. The Q tri scale was calibrated using the cardiac output. Values of E max triQ and Q max triQ obtained using Q tri were compared with those of E max mQ and Q max mQ obtained from the measured Q m . Healthy rats and rats with chronic kidney disease or diabetes mellitus were examined. We found that the LV E max and Q max can be approximately calculated using the assumed Q tri , and they strongly correlated with the corresponding values derived from Q m ( P < 0.0001; n = 78): E max triQ = 51.9133 + 0.8992 × E max mQ ( r 2 = 0.8257; P < 0.0001); Q max triQ = 2.4053 + 0.9767 × Q max mQ ( r 2 = 0.7798; P < 0.0001). Our findings suggest that the proposed technique can be a useful tool for determining E max and Q max by using a single LV pressure pulse together with cardiac output.

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Noninvasive vascular diagnostic testing: Techniques and clinical applications

Cited by 24 publications

References 100 publications

Determination of Aortic Pulse Wave Velocity From Waveform Decomposition of the Central Aortic Pressure Pulse

Determination of Aortic Pulse Wave Velocity From Waveform Decomposition of the Central Aortic Pressure Pulse

The usefulness of a laser Doppler in the measurement of toe blood pressures

Quantification of cardiac pumping mechanics in rats by using the elastance–resistance model based solely on the measured left ventricular pressure and cardiac output

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