Three-dimensional printed flow phantom model of the carotid artery in preterm infants for training and research

The aim of this study was to perform flow volume measurements with Doppler ultrasound using novel 3D printed flow phantom models of carotid artery in preterm infants with varying characteristics. Clinical data from cerebral blood flow measurements using Doppler ultrasound of the right common carotid artery from premature newborn infants were used to produce a 3D printed Doppler flow phantom model with three different vessel diameters; 0.158 cm, 0.196 cm and 0.244 cm. Leading edge to centre was used to measure vessel diameter. Two observers performed flow volume measurements using continuous and pulsatile flow. Agreement between observers was examined using Bland-Altman plots. 24 measurements were performed. 18 (75%) measurements were performed using continuous flow. Pulsatile flow measurements were performed on lumen diameter of 0.244 cm only using physiological rates. Bland-Altman analysis for continuous flow measurements for observer 1 and 2 were -0.007 (95%LOA -4.3 to 4.3) ml/min and 3.2 (95%LOA -2.7 to 9.1) ml/min. Bias for pulsatile flow measurements for observer 1 and 2 were 1.5 (95%LOA -0.8 to 3.8) ml/min and 4.6 (0.7 to 8.5) ml/min respectively. Inter and intra-observer reliability was excellent for majority of measurements. The mean coefficient of variation for inter observer diameter measurements was 1.2% and intra observer measurements were between 1.5% to 3.9% for both observers. Flow volume measurements performed using 3D printed materials resulted in realistic echogenicities mimicking biological tissues. Validity and reliability studies, within and between, observers showed acceptable results. Researchers and clinicians can use this model for further training and simulation.

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A realistic flow phantom model of the carotid artery in preterm infants for training and research

Ultrasound ◽

10.1177/1742271x20902189 ◽

2020 ◽

Vol 28 (3) ◽

pp. 145-154

Author(s):

Sujith Pereira ◽

Jonathan Reeves ◽

Malcolm Birch ◽

Sakthi Finton-James ◽

Komal Verma ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Carotid Artery ◽

Preterm Infants ◽

Pulsatile Flow ◽

Vessel Diameter ◽

Flow Measurements ◽

Phantom Model ◽

Flow Phantom ◽

Volume Measurements

Introduction Cerebral blood flow is increasingly monitored in preterm infants. Doppler ultrasound of the carotid artery is a widely available method but is operator dependent. Our aim was to design and produce a realistic flow phantom model of the carotid artery of preterm infants. Methods Data from cerebral blood flow measurements using Doppler ultrasound of the right common carotid artery from 21 premature newborn infants were used to produce a Doppler flow phantom model with three different vessel diameters. Vessel diameter, continuous and pulsatile flow volume measurements were performed by two blinded observers (with more than eight and 20 years of experience). Results Vessel diameter measurements using the phantom were underestimated by 7%. Continuous flow volume measurements were overestimated by 7% by both observers (observer 1 mean difference 1.5 ± 1.96 SD −3.3 to 6.3 ml/min versus observer 2, 1.9 ± 1.96 SD −3.6 to 7.4 ml/min). Pulsatile flow measurements were overestimated by 12.6% by observer 1 (2.7 ± 1.96 SD −0.6 to 5.9 ml/min) and by 7.8% by observer 2 (1.7 ± 1.96 SD −1.6 to 4.9 ml/min). There was good interobserver and intraobserver reliability for the majority of measurements using continuous and pulsatile flow. Conclusion It is feasible to produce a realistic flow phantom model of the neonatal carotid artery of preterm infants. Diameter measurements were underestimated and flow measurements were overestimated. These errors fell within acceptable limits for in vivo measurements. If these limitations were related to materials, this could be explored using a wall-less model. The flow phantom could be utilised for research and training clinicians in measuring cerebral blood flow using the carotid artery in this vulnerable group of infants.

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Diameter measurements in three-dimensional printed flow phantom model of the carotid artery in preterm infants

Journal of Biomedical Engineering and Medical Imaging ◽

10.14738/jbemi.86.11166 ◽

2021 ◽

Vol 8 (6) ◽

pp. 8-21

Author(s):

Sujith Pereira ◽

Jonathan Reeves ◽

Malcolm Birch ◽

Ahmed Ali ◽

Ajay Sinha ◽

...

Keyword(s):

Blood Flow ◽

Carotid Artery ◽

Preterm Infants ◽

Three Dimensional ◽

Lumen Diameter ◽

Diameter Measurement ◽

Phantom Model ◽

Observer Reliability ◽

Flow Phantom ◽

3D Printed

Diameter form an integral part of blood flow measurement. This study aimed to explore different three-dimensional (3D) printed materials to develop flow phantom models of the carotid artery in preterm newborn infants and to investigate ideal diameter measurement points using ultrasound that reflected accurate lumen diameter measurement. Cerebral blood flow measurements data using Doppler ultrasound of the right common carotid artery from 21 randomly selected preterm infants were used to produce a 3D printed Doppler flow phantom model with three different vessel diameters. Diameters were measured by multiple observers blinded to phantom vessel characteristics and each other’s measurements. 9 measurement points were studied. Agreement between observers, inter and intra observer reliability and coefficient of variation (CoV) was examined. Of the 63 diameter measurements, 45 (71%) were performed on flow phantoms with vessel diameter of 0.196 cm. Bland-Altman plots revealed that measurement performed using leading edge to centre (mean bias 1.8% {95%LOA -4.1% to 7.7%}) and centre to trailing edge (mean bias 1.1% {95%LOA -5.4% to 7.8%}) resulted in the most accurate lumen diameter measurements. Inter and intra-observer reliability was excellent. The mean CoV for inter observer measurements was 1.7% and intra observer measurements was 1.6% and 1.8% for each observer. We successfully produced a 3D printed flow phantom model of the carotid artery in preterm infants and identified two measurement methods that result in reliable and accurate lumen diameter measurement. Researchers and clinicians can use this information for further studies involving ultrasound diameter measurements in small calibre vessels.

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Common carotid artery blood flow volume in extremely preterm infants

Acta Paediatrica ◽

10.1111/apa.15655 ◽

2020 ◽

Author(s):

Sujith S. Pereira ◽

Ajay K. Sinha ◽

Divyen K. Shah ◽

Stephen T. Kempley

Keyword(s):

Blood Flow ◽

Carotid Artery ◽

Preterm Infants ◽

Common Carotid Artery ◽

Flow Volume ◽

Artery Blood Flow ◽

Blood Flow Volume ◽

Extremely Preterm ◽

Extremely Preterm Infants

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Development of Custom Wall-Less Cardiovascular Flow Phantoms with Tissue-Mimicking Gel

Cardiovascular Engineering and Technology ◽

10.1007/s13239-021-00546-7 ◽

2021 ◽

Author(s):

Megan E. Laughlin ◽

Sam E. Stephens ◽

Jamie A. Hestekin ◽

Morten O. Jensen

Keyword(s):

Mechanical Properties ◽

Continuous Flow ◽

Cardiac Tissue ◽

Flow Imaging ◽

Straight Channel ◽

Young’S Moduli ◽

Flow Phantom ◽

Cardiovascular Flow ◽

3D Printed

Abstract Purpose Flow phantoms are used in experimental settings to aid in the simulation of blood flow. Custom geometries are available, but current phantom materials present issues with degradability and/or mimicking the mechanical properties of human tissue. In this study, a method of fabricating custom wall-less flow phantoms from a tissue-mimicking gel using 3D printed inserts is developed. Methods A 3D blood vessel geometry example of a bifurcated artery model was 3D printed in polyvinyl alcohol, embedded in tissue-mimicking gel, and subsequently dissolved to create a phantom. Uniaxial compression testing was performed to determine the Young’s moduli of the five gel types. Angle-independent, ultrasound-based imaging modalities, Vector Flow Imaging (VFI) and Blood Speckle Imaging (BSI), were utilized for flow visualization of a straight channel phantom. Results A wall-less phantom of the bifurcated artery was fabricated with minimal bubbles and continuous flow demonstrated. Additionally, flow was visualized through a straight channel phantom by VFI and BSI. The available gel types are suitable for mimicking a variety of tissue types, including cardiac tissue and blood vessels. Conclusion Custom, tissue-mimicking flow phantoms can be fabricated using the developed methodology and have potential for use in a variety of applications, including ultrasound-based imaging methods. This is the first reported use of BSI with an in vitro flow phantom.

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Measuring pulmonary arterial compliance: mission impossible? Insights from a novel in vivo continuous-flow based experimental model

Pulmonary Circulation ◽

10.1177/2045894018776882 ◽

2018 ◽

Vol 8 (2) ◽

pp. 204589401877688 ◽

Cited By ~ 2

Author(s):

Frédéric Vanden Eynden ◽

Thierry Bové ◽

Marie-Luce Chirade ◽

Guido Van Nooten ◽

Patrick Segers

Keyword(s):

Steady Flow ◽

Pulse Pressure ◽

Pulsatile Flow ◽

Pulmonary Circulation ◽

Continuous Flow ◽

Arterial Compliance ◽

Exponential Fitting ◽

Flow Conditions ◽

Flow Measurements ◽

Pulmonary Arterial

Arterial compliance (C) is related to the elasticity, size, and geometrical distribution of arteries. Compliance is a determinant of the load that impedes ventricular ejection. Measuring compliance is difficult, particularly in the pulmonary circulation in which resistive and compliant vessels overlap. Comparing different methods for quantification of compliance to a method that involves a continuous flow might help to identify the optimal method. Pulmonary arterial compliance was computed in six pigs based on the stroke volume to pulse pressure ratio, diastolic decay exponential fitting, area method, and the pulse pressure method (PPM). Compliance measurements were compared to those obtained under continuous flow conditions through a right ventricular bypass (Heartware Inc., Miami Lakes, FL, USA). Compliance was computed for various flows using diastolic decay exponential fitting after an abrupt interruption of the pump. Under the continuous flow conditions, resistance (R) was a decreasing function of the flow, and the fitting to P = e-t/RC yielded a pulmonary time constant (RC) of 2.06 s ( ± 0.48). Compliance was an increasing function of flow. Steady flow inter-method comparisons of compliance under pulsatile flow conditions showed large discrepancies and values (7.23 ± 4.47 mL/mmHg) which were lower than those obtained under continuous flow conditions (10.19 ± 1 0.31 mL/mmHg). Best agreement with steady flow measurements is obtained with the diastolic decay method. Resistance and compliance are both flow-dependent and are inversely related in the pulmonary circulation. The dynamic nature of the pulsatile flow may induce a non-uniformly distributed compliance, with an influence on the methods of measurement.

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Restoration of Pulsatile Flow Leads to a Reduction in Sympathetic Nerve Activity Among Patients With Continuous-Flow Left Ventricular Assist Devices

The Journal of Heart and Lung Transplantation ◽

10.1016/j.healun.2015.01.160 ◽

2015 ◽

Vol 34 (4) ◽

pp. S62-S63

Author(s):

W.K. Cornwell ◽

T. Tarumi ◽

A. Stickford ◽

J. Kibe ◽

C. Fitzsimmons ◽

...

Keyword(s):

Pulsatile Flow ◽

Sympathetic Nerve ◽

Continuous Flow ◽

Sympathetic Nerve Activity ◽

Left Ventricular ◽

Ventricular Assist Devices ◽

Left Ventricular Assist Devices ◽

Nerve Activity ◽

Ventricular Assist ◽

Left Ventricular Assist

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Aortic growth arrest after preterm birth: a lasting structural change of the vascular tree

Journal of Developmental Origins of Health and Disease ◽

10.1017/s2040174411000274 ◽

2011 ◽

Vol 2 (4) ◽

pp. 218-225 ◽

Cited By ~ 18

Author(s):

U. Schubert ◽

M. Müller ◽

A.-K. Edstedt Bonamy ◽

H. Abdul-Khaliq ◽

M. Norman

Keyword(s):

Preterm Birth ◽

Carotid Artery ◽

Preterm Infants ◽

Growth Failure ◽

Later Life ◽

Postnatal Growth ◽

Direct Result ◽

Arterial Tree ◽

Very Preterm Infants ◽

Very Preterm

Young people who are born very preterm exhibit a narrower arterial tree as compared with people born at term. We hypothesized that such arterial narrowing occurs as a direct result of premature birth. The aim of this study was to compare aortic and carotid artery growth in infants born preterm and at term. Observational and longitudinal cohort study of 50 infants (21 born very preterm, all appropriate for gestational age, 29 controls born at term) was conducted. Diameters of the upper abdominal aorta and common carotid artery were measured with ultrasonography at three months before term, at term and three months after term-equivalent age. At the first assessment, the aortic end-diastolic diameter (aEDD) was slightly larger in very preterm infants as compared with fetal dimensions. Fetal aortic EDD increased by 2.6 mm during the third trimester, whereas very preterm infants exhibited 0.9 mm increase in aEDD during the same developmental period (P < 0.001 for group difference). During the following 3-month period, aortic growth continued unchanged (+0.9 mm) in very preterm infants, whereas postnatal growth in term controls slowed down to +1.3 mm (P < 0.001 v. fetal aortic growth). At the final examination, aEDD was 22% and carotid artery EDD was 14% narrower in infants born preterm compared with controls, also after adjusting for current weight (P < 0.01). Aortic and carotid artery growth is impaired after very preterm birth, resulting in arterial narrowing. Arterial growth failure may be a generalized vascular phenomenon after preterm birth, with implications for cardiovascular morbidity in later life.

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Clinical Utility of Quantitative Cerebral Blood Flow Measurements during Internal Carotid Artery Test Occlusions

Neurosurgery ◽

10.1227/00006123-200205000-00012 ◽

2002 ◽

Vol 50 (5) ◽

pp. 996-1005 ◽

Cited By ~ 1

Author(s):

Randolph S. Marshall ◽

Ronald M. Lazar ◽

William L. Young ◽

Robert A. Solomon ◽

Shailendra Joshi ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Carotid Artery ◽

Internal Carotid Artery ◽

Clinical Utility ◽

Internal Carotid ◽

Flow Measurements ◽

Blood Flow Measurements

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Quantitative flow measurement after placing a flow diverter for a distal internal carotid artery aneurysm

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2016-012730 ◽

2016 ◽

Vol 9 (12) ◽

pp. 1238-1242 ◽

Cited By ~ 2

Author(s):

Chien-Wei Chen ◽

Ho-Fai Wong ◽

Yu-Ling Ye ◽

Yao-Liang Chen ◽

Wei-Liang Chen ◽

...

Keyword(s):

Carotid Artery ◽

Internal Carotid Artery ◽

Cerebral Artery ◽

Internal Carotid ◽

Flow Diverter ◽

Peak Time ◽

Flow Measurements ◽

Distal Internal Carotid Artery ◽

Aneurysm Volume ◽

Quantitative Flow

ObjectivesTo evaluate the differences in arterial flow after flow diverter placement using quantitative flow measurements based on digital subtraction angiography (DSA).MethodsBetween November 2013 and November 2015, all patients who had flow diverters placed for distal internal carotid artery (ICA) aneurysms were reviewed. Patients in whom the stent was placed across the ostia of the ophthalmic artery (OphA) and anterior choroidal artery (AChA) were enrolled. Five regions of interest were selected: the proximal ICA (as a reference), terminal ICA, middle cerebral artery (MCA), anterior cerebral artery (ACA), OphA, and AChA. The values of the peak, time-to-peak (TTP), and area under the curve (AUC) were analyzed using a quantitative DSA technique.ResultsThe study enrolled 13 patients. The quantitative flow analysis showed improved flow in the terminal ICA (peak and AUC, p=0.036 and p=0.04, respectively), MCA (AUC, p=0.023), and ACA (AUC, p=0.006), and decreased flow in the OphA (peak and AUC, p=0.013 and p=0.005, respectively) and AChA (peak and subtracted TTP, p=0.023 and p=0.050, respectively) after flow diverter placement. Larger aneurysm volume was significantly correlated with decreased OphA flow after the procedure (peak and AUC, p=0.049 and p=0.037, respectively). Larger aneurysm volume also had a marginal correlation with increased distal ICA flow after the procedure, but this did not reach significance (peak and AUC, p=0.195 and p=0.060, respectively).ConclusionsWithout using extra contrast medium or radiation dosages, color-coded DSA enables quantitative monitoring of the cerebral circulation after flow-diverting treatment.

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