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Shi H, Wang J, Vorvolakos K, White K, Duraiswamy N. Pre-clinical evaluation of surface coating performance in guidewire surrogates: Potential implications for coated interventional surgical devices. J Biomater Appl 2019; 34:928-941. [PMID: 31752582 DOI: 10.1177/0885328219884453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Huiyu Shi
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratories (OSEL), Division of Applied Mechanics (DAM), USA
| | - Jonathan Wang
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratories (OSEL), Division of Applied Mechanics (DAM), USA
| | - Katherine Vorvolakos
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratories (OSEL), Division of Biology, Chemistry, and Material Science (DBCMS), USA
| | - Kathleen White
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Office of Product Evaluation and Quality (OPEQ), USA
| | - Nandini Duraiswamy
- Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratories (OSEL), Division of Applied Mechanics (DAM), USA
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Chayer B, van den Hoven M, Cardinal MHR, Li H, Swillens A, Lopata R, Cloutier G. Atherosclerotic carotid bifurcation phantoms with stenotic soft inclusions for ultrasound flow and vessel wall elastography imaging. ACTA ACUST UNITED AC 2019; 64:095025. [DOI: 10.1088/1361-6560/ab1145] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Sharei H, Alderliesten T, van den Dobbelsteen JJ, Dankelman J. Navigation of guidewires and catheters in the body during intervention procedures: a review of computer-based models. J Med Imaging (Bellingham) 2018; 5:010902. [PMID: 29392159 PMCID: PMC5787668 DOI: 10.1117/1.jmi.5.1.010902] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/04/2018] [Indexed: 11/29/2022] Open
Abstract
Guidewires and catheters are used during minimally invasive interventional procedures to traverse in vascular system and access the desired position. Computer models are increasingly being used to predict the behavior of these instruments. This information can be used to choose the right instrument for each case and increase the success rate of the procedure. Moreover, a designer can test the performance of instruments before the manufacturing phase. A precise model of the instrument is also useful for a training simulator. Therefore, to identify the strengths and weaknesses of different approaches used to model guidewires and catheters, a literature review of the existing techniques has been performed. The literature search was carried out in Google Scholar and Web of Science and limited to English for the period 1960 to 2017. For a computer model to be used in practice, it should be sufficiently realistic and, for some applications, real time. Therefore, we compared different modeling techniques with regard to these requirements, and the purposes of these models are reviewed. Important factors that influence the interaction between the instruments and the vascular wall are discussed. Finally, different ways used to evaluate and validate the models are described. We classified the developed models based on their formulation into finite-element method (FEM), mass-spring model (MSM), and rigid multibody links. Despite its numerical stability, FEM requires a very high computational effort. On the other hand, MSM is faster but there is a risk of numerical instability. The rigid multibody links method has a simple structure and is easy to implement. However, as the length of the instrument is increased, the model becomes slower. For the level of realism of the simulation, friction and collision were incorporated as the most influential forces applied to the instrument during the propagation within a vascular system. To evaluate the accuracy, most of the studies compared the simulation results with the outcome of physical experiments on a variety of phantom models, and only a limited number of studies have done face validity. Although a subset of the validated models is considered to be sufficiently accurate for the specific task for which they were developed and, therefore, are already being used in practice, these models are still under an ongoing development for improvement. Realism and computation time are two important requirements in catheter and guidewire modeling; however, the reviewed studies made a trade-off depending on the purpose of their model. Moreover, due to the complexity of the interaction with the vascular system, some assumptions have been made regarding the properties of both instruments and vascular system. Some validation studies have been reported but without a consistent experimental methodology.
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Affiliation(s)
- Hoda Sharei
- Delft University of Technology, Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft, The Netherlands
| | - Tanja Alderliesten
- Academic Medical Center, Department of Radiation Oncology, Amsterdam, The Netherlands
| | - John J. van den Dobbelsteen
- Delft University of Technology, Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft, The Netherlands
| | - Jenny Dankelman
- Delft University of Technology, Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft, The Netherlands
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Chee AJY, Ho CK, Yiu BYS, Yu ACH. Walled Carotid Bifurcation Phantoms for Imaging Investigations of Vessel Wall Motion and Blood Flow Dynamics. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2016; 63:1852-1864. [PMID: 27429436 DOI: 10.1109/tuffc.2016.2591946] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
As a major application domain of vascular ultrasound, the carotid artery has long been the subject of anthropomorphic phantom design. It is nevertheless not trivial to develop walled carotid phantoms that are compatible for use in integrative imaging of carotid wall motion and flow dynamics. In this paper, we present a novel phantom design protocol that can enable efficient fabrication of walled carotid bifurcation phantoms with: (i) high acoustic compatibility, (ii) artery-like vessel elasticity, and (iii) stenotic narrowing feature. Our protocol first involved direct fabrication of the vessel core and an outer mold using computer-aided design tools and 3-D printing technology; these built parts were then used to construct an elastic vessel tube through investment casting of a polyvinyl alcohol containing mixture, and an agar-gelatin tissue mimicking slab was formed around the vessel tube. For demonstration, we applied our protocol to develop a set of healthy and stenosed (25%, 50%, 75%) carotid bifurcation phantoms. Plane wave imaging experiments were performed on these phantoms using an ultrasound scanner with channel-level configurability. Results show that the wall motion dynamics of our phantoms agreed with pulse wave propagation in an elastic vessel (pulse wave velocity of 4.67±0.71 m/s measured at the common carotid artery), and their flow dynamics matched the expected ones in healthy and stenosed bifurcation (recirculation and flow jet formation observed). Integrative imaging of vessel wall motion and blood flow dynamics in our phantoms was also demonstrated, from which we observed fluid-structure interaction differences between healthy and diseased bifurcation phantoms. These findings show that the walled bifurcation phantoms developed with our new protocol are useful in vascular imaging studies that individually or jointly assess wall motion and flow dynamics.
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Nikitichev DI, Barburas A, McPherson K, Mari JM, West SJ, Desjardins AE. Construction of 3-Dimensional Printed Ultrasound Phantoms With Wall-less Vessels. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2016; 35:1333-9. [PMID: 27162278 DOI: 10.7863/ultra.15.06012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/15/2015] [Indexed: 05/08/2023]
Abstract
Ultrasound phantoms are invaluable as training tools for vascular access procedures. We developed ultrasound phantoms with wall-less vessels using 3-dimensional printed chambers. Agar was used as a soft tissue-mimicking material, and the wall-less vessels were created with rods that were retracted after the agar was set. The chambers had integrated luer connectors to allow for fluid injections with clinical syringes. Several variations on this design are presented, which include branched and stenotic vessels. The results show that 3-dimensional printing can be well suited to the construction of wall-less ultrasound phantoms, with designs that can be readily customized and shared electronically.
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Affiliation(s)
- Daniil I Nikitichev
- Department of Medical Physics and Biomedical Engineering, University College London, London, England
| | - Anamaria Barburas
- Department of Medical Physics and Biomedical Engineering, University College London, London, England
| | | | - Jean-Martial Mari
- Department of Medical Physics and Biomedical Engineering, University College London, London, EnglandUniversity of French Polynesia, Tahiti, French Polynesia
| | | | - Adrien E Desjardins
- Department of Medical Physics and Biomedical Engineering, University College London, London, England
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Conconi MT, Borgio L, Di Liddo R, Sartore L, Dalzoppo D, Amistà P, Lora S, Parnigotto PP, Grandi C. Evaluation of vascular grafts based on polyvinyl alcohol cryogels. Mol Med Rep 2014; 10:1329-34. [PMID: 24969541 DOI: 10.3892/mmr.2014.2348] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 02/27/2014] [Indexed: 11/06/2022] Open
Abstract
The present study designed and developed blood vessel substitutes (BVSs) composed of polyvinyl alcohol (PVA) cryogels. The in vitro results demonstrated that the coating of the polymer with lyophilized decellularized vascular matrix (DVM) greatly enhanced the adhesion of human umbilical vein endothelial cells (HUVECs). However, when PVA̸DVM BVSs were implanted into the abdominal aorta of Sprague‑Dawley rats, DVM was identified as a highly thrombogenic surface resulting in the mortality of all animals 3‑4 days after surgery. By contrast, all rats implanted with PVA survived and were sacrificed after 12 months. The luminal surface of the explanted grafts was completely covered by endothelial cells and the inner diameter was similar to that of the original vessel. In conclusion, the present study indicated that PVA may be considered as a promising biomaterial for the fabrication of artificial vessels.
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Affiliation(s)
- Maria Teresa Conconi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua 35131, Italy
| | - Luca Borgio
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua 35131, Italy
| | - Rosa Di Liddo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua 35131, Italy
| | - Leonardo Sartore
- Department of Plastic and Reconstructive Surgery, University of Padua, Padua 35131, Italy
| | - Daniele Dalzoppo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua 35131, Italy
| | - Pietro Amistà
- Department of Neuroradiology, Hospital of Rovigo, Rovigo 45100, Italy
| | - Silvano Lora
- Foundation for Biology and Regenerative Medicine, TES‑Tissue Engineering and Signaling (ONLUS), Padua 35131, Italy
| | - Pier Paolo Parnigotto
- Foundation for Biology and Regenerative Medicine, TES‑Tissue Engineering and Signaling (ONLUS), Padua 35131, Italy
| | - Claudio Grandi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua 35131, Italy
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Lai SSM, Yiu BYS, Poon AKK, Yu ACH. Design of anthropomorphic flow phantoms based on rapid prototyping of compliant vessel geometries. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1654-1664. [PMID: 23791354 DOI: 10.1016/j.ultrasmedbio.2013.03.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 02/25/2013] [Accepted: 03/09/2013] [Indexed: 06/02/2023]
Abstract
Anatomically realistic flow phantoms are essential experimental tools for vascular ultrasound. Here we describe how these flow phantoms can be efficiently developed via a rapid prototyping (RP) framework that involves direct fabrication of compliant vessel geometries. In this framework, anthropomorphic vessel models were drafted in computer-aided design software, and they were fabricated using stereolithography (one type of RP). To produce elastic vessels, a compliant photopolymer was used for stereolithography. We fabricated a series of compliant, diseased carotid bifurcation models with eccentric stenosis (50%) and plaque ulceration (types I and III), and they were used to form thin-walled flow phantoms by coupling the vessels to an agar-based tissue-mimicking material. These phantoms were found to yield Doppler spectrograms with significant spectral broadening and color flow images with mosaic patterns, as typical of disturbed flow under stenosed and ulcerated disease conditions. Also, their wall distension behavior was found to be similar to that observed in vivo, and this corresponded with the vessel wall's average elastic modulus (391 kPa), which was within the nominal range for human arteries. The vessel material's acoustic properties were found to be sub-optimal: the estimated average acoustic speed was 1801 m/s, and the attenuation coefficient was 1.58 dB/(mm·MHz(n)) with a power-law coefficient of 0.97. Such an acoustic mismatch nevertheless did not notably affect our Doppler spectrograms and color flow image results. These findings suggest that phantoms produced from our design framework have the potential to serve as ultrasound-compatible test beds that can simulate complex flow dynamics similar to those observed in real vasculature.
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Affiliation(s)
- Simon S M Lai
- Medical Engineering Program, University of Hong Kong, Pokfulam, Hong Kong SAR, China
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Esmonde-White FWL, Esmonde-White KA, Kole MR, Goldstein SA, Roessler BJ, Morris MD. Biomedical tissue phantoms with controlled geometric and optical properties for Raman spectroscopy and tomography. Analyst 2011; 136:4437-46. [PMID: 21912794 PMCID: PMC3289090 DOI: 10.1039/c1an15429j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
To support the translation of Raman spectroscopy into clinical applications, synthetic models are needed to accurately test, optimize and validate prototype fiber optic instrumentation. Synthetic models (also called tissue phantoms) are widely used for developing and testing optical instrumentation for diffuse reflectance, fluorescence, and Raman spectroscopies. While existing tissue phantoms accurately model tissue optical scattering and absorption, they do not typically model the anatomic shapes and chemical composition of tissue. Because Raman spectroscopy is sensitive to molecular composition, Raman tissue phantoms should also approximate the bulk tissue composition. We describe the fabrication and characterization of tissue phantoms for Raman tomography and spectroscopy. These phantoms have controlled chemical and optical properties, and also multilayer morphologies which approximate the appropriate anatomic shapes. Tissue phantoms were fabricated to support on-going Raman studies by simulating the human wrist and rat leg. Surface meshes (triangle patch models) were generated from computed tomography (CT) images of a human arm and rat leg. Rapid prototyping was used to print mold templates with complex geometric patterns. Plastic casting techniques used for movie special effects were adapted to fabricate molds from the rapid prototypes, and finally to cast multilayer gelatin tissue phantoms. The gelatin base was enriched with additives to model the approximate chemistry and optical properties of individual tissue layers. Additional studies were performed to determine optimal casting conditions, phantom stability, layer delamination and chemical diffusion between layers. Recovery of diffuse reflectance and Raman spectra in tissue phantoms varied with probe placement. These phantoms enable optimization of probe placement for human or rat studies. These multilayer tissue phantoms with complex geometries are shown to be stable, with minimal layer delamination and chemical diffusion.
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Ene F, Gachon C, Delassus P, Carroll R, Stefanov F, O'Flynn P, Morris L. In vitro evaluation of the effects of intraluminal thrombus on abdominal aortic aneurysm wall dynamics. Med Eng Phys 2011; 33:957-66. [PMID: 21478044 DOI: 10.1016/j.medengphy.2011.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 03/12/2011] [Accepted: 03/14/2011] [Indexed: 10/18/2022]
Abstract
The optimum time to treat abdominal aortic aneurysms (AAAs) still remains an uncertain issue. The decision to intervene does not take in account the effects that wall curvature, intraluminal thrombus (ILT) properties and thickness have on rupture. The role of ILT in aneurysm dynamics and rupture has been controversial. In vitro testing of four silicone AAA models incorporating the ILT and aortic bifurcation was studied under physiological conditions. Pressures (P) and diameters (D) were analysed for models with and without ILT at different locations. The diametral strain, compliance and P/D curves were influenced by the presence, elastic stiffness and thickness of the ILT. In this case, the inclusion of ILT reduced the lumen area by 77% that resulted in a 0.5-81% reduction in compliance depending on ILT properties. With an increase in ILT stiffness from 0.05 to 0.2 MPa, the compliance was reduced by 81%. In the region of maximum diameter, there was a reduction of diametral strain and compliance except for the softer ILT which was more compliant throughout the proximal region. The shifting of the maximum diametral strain and compliance to the proximal neck was pronounced by an increase in ILT stiffness, thus creating a possible rupture site.
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Affiliation(s)
- Florentina Ene
- Department of Mechanical Engineering, Galway Medical Technologies Centre (GMedTech), Galway Mayo Institute of Technology (GMIT), Dublin Road, Galway, Ireland.
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Thakur Y, Nikolov HN, Gulka IB, Holdsworth DW, Drangova M. Design and construction of a multipath vessel phantom for interventional training. Br J Radiol 2010; 83:979-82. [PMID: 20965908 DOI: 10.1259/bjr/91767642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
This short communication reports on the design and construction of a catheter manipulation skill enhancement phantom for use by residents and fellows outside the clinical environment. The phantom contains a variety of path trajectories and vessel diameter transitions, allowing trainees to manipulate catheters through vessel paths of varying difficulty. The multipath phantom, which is easy to construct and provides easily visualised paths, provides a simple, cost-effective training platform to facilitate and accelerate interventional training.
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Affiliation(s)
- Y Thakur
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.
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King DM, Ring M, Moran CM, Browne JE. Development of a range of anatomically realistic renal artery flow phantoms. ULTRASOUND IN MEDICINE & BIOLOGY 2010; 36:1135-1144. [PMID: 20620700 DOI: 10.1016/j.ultrasmedbio.2010.04.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 04/18/2010] [Accepted: 04/29/2010] [Indexed: 05/29/2023]
Abstract
Computer-aided modelling techniques were used to generate a range of anatomically realistic phantoms of the renal artery from medical images of a 64-slice CT data set acquired from a healthy volunteer. From these data, models of a normal healthy renal artery and diseased renal arteries with 30%, 50%, 70% and 85% stenoses were generated. Investment casting techniques and a low melting point alloy were used to create the vessels with varying degrees of stenosis. The use of novel inserts significantly reduced the time, materials and cost required in the fabrication of these anatomically realistic phantoms. To prevent residual metal remaining in the final phantom lumens a technique employing clingfilm was used to remove all molten metal from the lumen. These novel flow phantoms developed using efficient methods for producing vessels with various degrees of stenosis can provide a means of evaluation of current and emerging ultrasound technology.
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Mathews DT, Birney YA, Cahill PA, McGuinness GB. Vascular cell viability on polyvinyl alcohol hydrogels modified with water-soluble and -insoluble chitosan. J Biomed Mater Res B Appl Biomater 2008; 84:531-40. [PMID: 17680667 DOI: 10.1002/jbm.b.30901] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Polyvinyl alcohol (PVA) hydrogels blended with chitosan or other biological macromolecules have shown promise for cell culture and tissue engineering. This study investigates the attachment and growth of bovine aortic endothelial (BAEC) and smooth muscle cells (BASMC) on the PVA hydrogels modified with water soluble and water insoluble chitosan. Cell adhesion on the surface of the membranes was examined by phase contrast microscopy while cell morphologies were studied using immunocytochemistry staining with EC and SMC specific biomarkers (F-actin and alpha actin respectively). Cells cultured on 6% PVA, 0.4% chitosan (water soluble and insoluble) hydrogel membranes displayed excellent adhesion and spreading characteristics, in addition to negligible cell structural morphological changes in comparison to a polystyrene control. Similar vascular cell adhesion features were apparent on PVA membranes blended with water-soluble and -insoluble chitosan. Fluorescent activated cell sorter (FACS) analysis was used to determine BAEC and BASMC proliferation and cell viability. Apoptotic levels in BAEC after 7 days were 12.8% +/- 2.5% on the PVA- chitosan WS-1 membrane and 10.1% +/- 1.5% on the control well (n = 3) while comparable results were also noted for BASMC. Equivalent proliferative activity was apparent for BAEC on the control and PVA-chitosan membrane after 7 days, while BASMC showed increased proliferative activity on the membranes. These results indicate that the PVA-chitosan blended hydrogel membranes show promise for cell culture and tissue engineering applications.
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Affiliation(s)
- D T Mathews
- School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin 9, Ireland
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Mathews DT, Birney YA, Cahill PA, McGuinness GB. Mechanical and morphological characteristics of poly(vinyl alcohol)/chitosan hydrogels. J Appl Polym Sci 2008. [DOI: 10.1002/app.28104] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
The objective of this research was to use abdominal computed tomography (CT) scans to non-invasively quantify anthropometrical data of the human stomach and to concomitantly create an anatomically correct and distensible ex-vivo gastric model. Thirty-three abdominal CT scans of human subjects were obtained and were imported into reconstruction software to generate 3D models of the stomachs. Anthropometrical data such as gastric wall thickness, gastric surface area and gastric volume were subsequently quantified. A representative 3D computer model was exported into a selective laser sintering (SLS) rapid prototyping machine to create an anatomically correct solid gastric model. Subsequently, a replica wax template of the SLS model was created. A negative mould was offset around the wax template such that the offset distance was equivalent to that of the gastric wall thickness. A silicone with similar mechanical properties to the human stomach was poured into the offset. The lost wax manufacturing technique was employed to create a hollow distensible stomach model. 3D computer gastric models were generated from the CT scans. A hollow distensible silicone ex-vivo gastric model with similar compliance to that of the human stomach was created. The anthropometrical data indicated that there is no significant relationship between BMI and gastric surface area or gastric volume. There were inter- and intra-group differences between groups with respect to gastric wall thickness. This study demonstrates that abdominal CT scans can be used to both non-invasively determine gastric anthropometrical data as well as create realistic ex-vivo stomach models.
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Affiliation(s)
- Jerome A Henry
- Department of Mechanical and Biomedical Engineering, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
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Watts DM, Sutcliffe CJ, Morgan RH, Meagher S, Wardlaw J, Connell M, Bastin ME, Marshall I, Ramnarine KV, Hoskins PR, Black RA. Anatomical flow phantoms of the nonplanar carotid bifurcation, part I: computer-aided design and fabrication. ULTRASOUND IN MEDICINE & BIOLOGY 2007; 33:296-302. [PMID: 17306699 DOI: 10.1016/j.ultrasmedbio.2006.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Revised: 07/28/2006] [Accepted: 08/10/2006] [Indexed: 05/14/2023]
Abstract
Doppler ultrasound is widely used in the diagnosis and monitoring of arterial disease. Current clinical measurement systems make use of continuous and pulsed ultrasound to measure blood flow velocity; however, the uncertainty associated with these measurements is great, which has serious implications for the screening of patients for treatment. Because local blood flow dynamics depend to a great extent on the geometry of the affected vessels, there is a need to develop anatomically accurate arterial flow phantoms with which to assess the accuracy of Doppler blood flow measurements made in diseased vessels. In this paper, we describe the computer-aided design and manufacturing (CAD-CAM) techniques that we used to fabricate anatomical flow phantoms based on images acquired by time-of-flight magnetic resonance imaging (TOF-MRI). Three-dimensional CAD models of the carotid bifurcation were generated from data acquired from sequential MRI slice scans, from which solid master patterns were made by means of stereolithography. Thereafter, an investment casting procedure was used to fabricate identical flow phantoms for use in parallel experiments involving both laser and Doppler ultrasound measurement techniques.
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Affiliation(s)
- D M Watts
- Department of Engineering, University of Liverpool, Liverpool, UK
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