scholarly journals Weighing Scale-Based Pulse Transit Time is a Superior Marker of Blood Pressure than Conventional Pulse Arrival Time

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Stephanie L.-O. Martin ◽  
Andrew M. Carek ◽  
Chang-Sei Kim ◽  
Hazar Ashouri ◽  
Omer T. Inan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Time Delay ◽  
Correlation Coefficient ◽  
Transit Time ◽  
Arrival Time ◽  
Mean Squared Error ◽  
Pulse Transit Time ◽  
Pulse Arrival Time ◽  
Squared Error ◽  
Pulse Arrival

Abstract Pulse transit time (PTT) is being widely pursued for cuff-less blood pressure (BP) monitoring. Most efforts have employed the time delay between ECG and finger photoplethysmography (PPG) waveforms as a convenient surrogate of PTT. However, these conventional pulse arrival time (PAT) measurements include the pre-ejection period (PEP) and the time delay through small, muscular arteries and may thus be an unreliable marker of BP. We assessed a bathroom weighing scale-like system for convenient measurement of ballistocardiography and foot PPG waveforms – and thus PTT through larger, more elastic arteries – in terms of its ability to improve tracking of BP in individual subjects. We measured “scale PTT”, conventional PAT, and cuff BP in humans during interventions that increased BP but changed PEP and smooth muscle contraction differently. Scale PTT tracked the diastolic BP changes well, with correlation coefficient of −0.80 ± 0.02 (mean ± SE) and root-mean-squared-error of 7.6 ± 0.5 mmHg after a best-case calibration. Conventional PAT was significantly inferior in tracking these changes, with correlation coefficient of −0.60 ± 0.04 and root-mean-squared-error of 14.6 ± 1.5 mmHg (p < 0.05). Scale PTT also tracked the systolic BP changes better than conventional PAT but not to an acceptable level. With further development, scale PTT may permit reliable, convenient measurement of BP.

Pulse arrival time is not an adequate surrogate for pulse transit time as a marker of blood pressure

2011 ◽  
Vol 111 (6) ◽  
pp. 1681-1686 ◽  
Author(s):  
Guanqun Zhang ◽  
Mingwu Gao ◽  
Da Xu ◽  
N. Bari Olivier ◽  
Ramakrishna Mukkamala
Keyword(s):  
Blood Pressure ◽  
Transit Time ◽  
Time Delays ◽  
Arrival Time ◽  
Mean Squared Error ◽  
Pulse Transit Time ◽  
Pulse Arrival Time ◽  
Squared Error ◽  
Evaluation Metric ◽  
Pulse Arrival

Pulse transit time (PTT) is a proven, simple to measure, marker of blood pressure (BP) that could potentially permit continuous, noninvasive, and cuff-less BP monitoring (after an initial calibration). However, pulse arrival time (PAT), which is equal to the sum of PTT and the pre-ejection period, is gaining popularity for BP tracking, because it is even simpler to measure. The aim of this study was to evaluate the hypothesis that PAT is an adequate surrogate for PTT as a marker of BP. PAT and PTT were estimated through the aorta using high-fidelity invasive arterial waveforms obtained from six dogs during wide BP changes induced by multiple interventions. These time delays and their reciprocals were evaluated in terms of their ability to predict diastolic, mean, and systolic BP (DBP, MBP, and SBP) per animal. The root mean squared error (RMSE) between the BP parameter predicted via the time delay and the measured BP parameter was specifically used as the evaluation metric. Taking the reciprocals of the time delays tended to reduce the RMSE values. The DBP, MBP, and SBP RMSE values for 1/PAT were 9.8 ± 5.2, 10.4 ± 5.6, and 11.9 ± 6.1 mmHg, whereas the corresponding values for 1/PTT were 5.3 ± 1.2, 4.8 ± 1.0, and 7.5 ± 2.2 mmHg ( P < 0.05). Thus tracking BP via PAT was not only markedly worse than via PTT but also unable to meet the FDA BP error limits. In contrast to previous studies, our results quantitatively indicate that PAT is not an adequate surrogate for PTT in terms of detecting challenging BP changes.

scholarly journals Author Correction: Weighing Scale-Based Pulse Transit Time is a Superior Marker of Blood Pressure than Conventional Pulse Arrival Time

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Stephanie L.-O. Martin ◽  
Andrew M. Carek ◽  
Chang-Sei Kim ◽  
Hazar Ashouri ◽  
Omer T. Inan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Transit Time ◽  
Arrival Time ◽  
Pulse Transit Time ◽  
Pulse Arrival Time ◽  
Pulse Arrival

scholarly journals Difference in Pulse Arrival Time at Forehead and at Finger as a Surrogate of Pulse Transit Time

2016 ◽  
Author(s):  
Jesus Lazaro ◽  
Raquel Bailon ◽  
Pablo Laguna ◽  
Vaidotas Mazoras ◽  
Andrius Rapalis ◽  
...  
Keyword(s):  
Transit Time ◽  
Arrival Time ◽  
Pulse Transit Time ◽  
Pulse Arrival Time ◽  
Pulse Arrival

scholarly journals Pulse arrival time as a surrogate of blood pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eoin Finnegan ◽  
Shaun Davidson ◽  
Mirae Harford ◽  
João Jorge ◽  
Peter Watkinson ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Time Delay ◽  
Arrival Time ◽  
Population Based ◽  
Left Ventricular ◽  
A Posteriori ◽  
Arterial Tree ◽  
Pulse Arrival Time ◽  
The Impact ◽  
Pulse Arrival

AbstractVarious models have been proposed for the estimation of blood pressure (BP) from pulse transit time (PTT). PTT is defined as the time delay of the pressure wave, produced by left ventricular contraction, measured between a proximal and a distal site along the arterial tree. Most researchers, when they measure the time difference between the peak of the R-wave in the electrocardiogram signal (corresponding to left ventricular depolarisation) and a fiducial point in the photoplethysmogram waveform (as measured by a pulse oximeter attached to the fingertip), describe this erroneously as the PTT. In fact, this is the pulse arrival time (PAT), which includes not only PTT, but also the time delay between the electrical depolarisation of the heart’s left ventricle and the opening of the aortic valve, known as pre-ejection period (PEP). PEP has been suggested to present a significant limitation to BP estimation using PAT. This work investigates the impact of PEP on PAT, leading to a discussion on the best models for BP estimation using PAT or PTT. We conducted a clinical study involving 30 healthy volunteers (53.3% female, 30.9 ± 9.35 years old, with a body mass index of 22.7 ± 3.2 kg/m$$^{2}$$ 2 ). Each session lasted on average 27.9 ± 0.6 min and BP was varied by an infusion of phenylephrine (a medication that causes venous and arterial vasoconstriction). We introduced new processing steps for the analysis of PAT and PEP signals. Various population-based models (Poon, Gesche and Fung) and a posteriori models (inverse linear, inverse squared and logarithm) for estimation of BP from PTT or PAT were evaluated. Across the cohort, PEP was found to increase by 5.5 ms ± 4.5 ms from its baseline value. Variations in PTT were significantly larger in amplitude, − 16.8 ms ± 7.5 ms. We suggest, therefore, that for infusions of phenylephrine, the contribution of PEP on PAT can be neglected. All population-based models produced large BP estimation errors, suggesting that they are insufficient for modelling the complex pathways relating changes in PTT or PAT to changes in BP. Although PAT is inversely correlated with systolic blood pressure (SBP), the gradient of this relationship varies significantly from individual to individual, from − 2946 to − 470.64 mmHg/s in our dataset. For the a posteriori inverse squared model, the root mean squared errors (RMSE) for systolic and diastolic blood pressure (DBP) estimation from PAT were 5.49 mmHg and 3.82 mmHg, respectively. The RMSEs for SBP and DBP estimation by PTT were 4.51 mmHg and 3.53 mmHg, respectively. These models take into account individual calibration curves required for accurate blood pressure estimation. The best performing population-based model (Poon) reported error values around double that of the a posteriori inverse squared model, and so the use of population-based models is not justified.

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