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Bhatti A, Ishii T, Saijo Y. Superficial Bifurcated Microflow Phantom for High-Frequency Ultrasound Applications. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:158-164. [PMID: 37872032 DOI: 10.1016/j.ultrasmedbio.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/13/2023] [Accepted: 10/04/2023] [Indexed: 10/25/2023]
Abstract
OBJECTIVE To evaluate and optimize high-frequency ultrasound (HFUS) imaging techniques that visualize the morphology of microscale vasculatures, many studies have used flow phantoms with straight channels. However, the previous phantoms lack the complexity of microvessels to simulate a realistic vascular environment in a shallow depth. This study was aimed at devising a new protocol for fabrication of a microflow phantom with bifurcated geometry at a superficial region. METHODS The proposed protocol involved the following features: (i) a bifurcated flow tract model 300 µm in diameter was debossed on the surface of a tissue slab made of polyvinyl alcohol cryogel, and (ii) a wall-less lumen was created via bonding tissue slabs to put a lid on the debossed flow tract. The structure of the created microflow phantom was evaluated using 2-D and 3-D power Doppler imaging with a 30 MHz HFUS modality. RESULTS Ultrasound imaging revealed that the desired flow tract with bifurcation was successfully created in the phantom at a depth of 2-5 mm from the ultrasound probe. The diameters of the flow tract measured in the axial direction were 307 ± 3.7 µm in the parent branch and 232 ± 18.2 and 256 ± 23.3 µm in the two daughter branches, respectively. CONCLUSION The experiments revealed that the proposed protocol for creating a microscale intricate flow tract with desired dimensions and depth is valid. This new phantom will facilitate further improvement in the ultrasound technologies for the precise visualization of superficial complex vasculatures such as those in skin layers.
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Affiliation(s)
- Anam Bhatti
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Takuro Ishii
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Miyagi, Japan.
| | - Yoshifumi Saijo
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, Japan
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Mobadersany N, Liang P, Kemper P, Konofagou EE. Polyvinyl Alcohol Phantoms With Heterogeneous Plaques: Estimation of Pulse Wave Velocity at the Stenotic Region Using Pulse Wave Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:91-98. [PMID: 37838523 PMCID: PMC11102764 DOI: 10.1016/j.ultrasmedbio.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 09/01/2023] [Accepted: 09/08/2023] [Indexed: 10/16/2023]
Abstract
OBJECTIVE Plaque characterization is essential for stroke prevention. In the study reported herein, we describe a heterogeneous phantom manufacturing technique with varying plaque compositions of different stiffness using polyvinyl alcohol (PVA) to emulate stenotic arteries and evaluated the use of pulse wave imaging (PWI) to assess plaque stiffness by comparing derived pulse wave velocities, with the goal of assessing plaque vulnerability and identifying high-risk patients for stroke. METHODS Five stenotic phantoms (50% stenosis) were fabricated by pouring PVA solutions into 3-D-printed molds. Two of the phantoms had heterogeneous plaque compositions of soft (E0 = 13 kPa) and intermediate (E0 = 40 kPa) materials and of stiff (E0 = 54 kPa) and intermediate materials. Ultrasound sequences were acquired as the arterial phantoms were connected to a pulsating pump, and PWI was performed on the ultrasound acquisition using normalized cross-correlation to track the pulse-induced phantom wall distension propagations. Pulse wave velocities were estimated by fitting a linear regression line between the arrival time of the peak acceleration of the wall distension waveform and the corresponding location. RESULTS Arterial phantoms with heterogeneous plaque stiffness were successfully fabricated. Pulse wave velocities of 2.06, 2.21, 2.49, 2.67 and 3.31 m/s were found in the phantom experiments using PWI for homogeneous soft plaque, the heterogeneous soft and intermediate plaque, homogeneous intermediate plaque, the heterogeneous stiff and intermediate plaque and homogeneous stiff plaque, respectively. CONCLUSION A novel arterial phantom building technique was reported with varying heterogenous plaque compositions of different stiffness. The feasibility of using PWI to evaluate plaque stiffness in stenotic arteries was determined and found that PWI can distinguish between plaques of distinct stiffness and composition.
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Affiliation(s)
- Nima Mobadersany
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Pengcheng Liang
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Paul Kemper
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Elisa E Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY, USA; Department of Radiology, Columbia University, New York, New York, NY, USA.
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Yambe K, Ishii T, Yiu BYS, Yu ACH, Endo T, Saijo Y. Ultrasound vector flow imaging during veno-arterial extracorporeal membrane oxygenation in a thoracic aorta model. J Artif Organs 2023:10.1007/s10047-023-01413-z. [PMID: 37474830 DOI: 10.1007/s10047-023-01413-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/11/2023] [Indexed: 07/22/2023]
Abstract
In veno-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment, the mixing zone is a key hemodynamic factor that determines the efficacy of the treatment. This study aimed to evaluate the applicability of a novel ultrasound technique called vector flow imaging (VFI) for visualizing complex flow patterns in an aorta phantom under VA-ECMO settings. VFI experiments were performed to image aortic hemodynamics under VA-ECMO treatment simulated in an anthropomorphic thoracic aorta phantom using a pulsatile pump (cardiac output: 2.7 L/min) and an ECMO pump with two different flow rates, 0.35 L/min and 1.0 L/min. The cardiac cycle of hemodynamics in the ascending aorta, aortic arch, and descending aorta was visualized, and the spatio-temporal dynamics of flow vectors were analyzed. VFI successfully visualized dynamic flow patterns in the aorta phantom. When the flow rate of the ECMO pump increased, ECMO flow was more dominant than cardiac output in the diastole phase, and the speed of cardiac output was suppressed in the systole phase. Vortex flow patterns were also detected in the ascending aorta and the arch under both ECMO flow rate conditions. The VFI technique may provide new insights into aortic hemodynamics and facilitates effective and safe VA-ECMO treatment.
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Affiliation(s)
- Kenichiro Yambe
- Graduate School of Medicine, Tohoku University, 2-1 Seiryo-Machi, Aoba-Ku, Sendai, Miyagi, 980-8575, Japan
- Department of Hepatobiliary and Pancreatic, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-Ku, Sendai, Miyagi, 983-8536, Japan
| | - Takuro Ishii
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki Aza Aoba, Aoba-Ku, Sendai, Miyagi, 980-8578, Japan.
- Graduate School of Biomedical Engineering, Tohoku University, 6-6-05 Aramaki Aza Aoba, Aoba-Ku, Sendai, Miyagi, 980-8579, Japan.
| | - Billy Y S Yiu
- Research Institute for Aging, University of Waterloo, 250 Laurelwood Drive, Waterloo, ON, N2J 0E2, Canada
| | - Alfred C H Yu
- Research Institute for Aging, University of Waterloo, 250 Laurelwood Drive, Waterloo, ON, N2J 0E2, Canada
| | - Tomoyuki Endo
- Division of Emergency and Disaster Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-Ku, Sendai, Miyagi, 983-8536, Japan
| | - Yoshifumi Saijo
- Graduate School of Medicine, Tohoku University, 2-1 Seiryo-Machi, Aoba-Ku, Sendai, Miyagi, 980-8575, Japan
- Graduate School of Biomedical Engineering, Tohoku University, 6-6-05 Aramaki Aza Aoba, Aoba-Ku, Sendai, Miyagi, 980-8579, Japan
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Dakok KK, Matjafri MZ, Suardi N, Oglat AA, Nabasu SE. A Review of Carotid Artery Phantoms for Doppler Ultrasound Applications. J Med Ultrasound 2021; 29:157-166. [PMID: 34729323 PMCID: PMC8515632 DOI: 10.4103/jmu.jmu_164_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/19/2021] [Accepted: 02/25/2021] [Indexed: 11/19/2022] Open
Abstract
Ultrasound imaging systems need tissue-mimicking phantoms with a good range of acoustic properties. Many studies on carotid artery phantoms have been carried out using ultrasound; hence this study presents a review of the different forms of carotid artery phantoms used to examine blood hemodynamics by Doppler ultrasound (DU) methods and explains the ingredients that constitute every phantom with their advantages and disadvantages. Different research databases were consulted to access relevant information on carotid artery phantoms used for DU measurements after which the information were presented systematically spanning from walled phantoms to wall-less phantoms. This review points out the fact that carotid artery phantoms are made up of tissue mimicking materials, vessel mimicking materials, and blood mimicking fluid whose properties matched those of real human tissues and vessels. These materials are a combination of substances such as water, gelatin, glycerol, scatterers, and other powders in their right proportions.
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Affiliation(s)
- Kyermang Kyense Dakok
- Department of Medical Physics and Radiation Science, School of Physics, Univirsti Sains Malaysia, Penang Malaysia, Nigeria
| | - Mohammed Zubir Matjafri
- Department of Medical Physics and Radiation Science, School of Physics, Univirsti Sains Malaysia, Penang Malaysia, Nigeria
| | - Nursakinah Suardi
- Department of Medical Physics and Radiation Science, School of Physics, Univirsti Sains Malaysia, Penang Malaysia, Nigeria
| | - Ammar Anwar Oglat
- Department of Medical Imaging, Faculty of Applied Medical Sciences, The Hashemite University, Zarqa, Joradan, Nigeria
| | - Seth Ezra Nabasu
- Department of Physics, Plateau State University Bokkos, Plateau State, Nigeria
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Wang S, Chen G, Yao B, Chee AJY, Wang Z, Du P, Qu S, Yu ACH. In Situ and Intraoperative Detection of the Ureter Injury Using a Highly Sensitive Piezoresistive Sensor with a Tunable Porous Structure. ACS APPLIED MATERIALS & INTERFACES 2021; 13:21669-21679. [PMID: 33929181 DOI: 10.1021/acsami.0c22791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Iatrogenic ureteral injury, as a commonly encountered problem in gynecologic, colorectal, and pelvic surgeries, is known to be difficult to detect in situ and in real-time. Consequently, this injury may be left untreated, thereby leading to serious complications such as infections, renal failure, or even death. Here, high-performance tubular porous pressure sensors were proposed to identify the ureter in situ intraoperatively. The electrical conductivity, mechanical compressibility, and sensor sensitivity can be tuned by changing the pore structure of porous conductive composites. A low percolation threshold of 0.33 vol % was achieved due to the segregated conductive network by pores. Pores also lead to a low effective Young's modulus and high compressibility of the composites and thus result in a high sensitivity of 448.2 kPa-1 of sensors, which is consistent with the results of COMSOL simulation. Self-mounted on the tip of forceps, the sensors can monitor tube pressures with different frequencies and amplitudes, as demonstrated using an artificial pump system. The sensors can also differentiate ureter pulses from aorta pulses of a Bama minipig in situ and in real-time. This work provides a facile, cost-effective, and nondestructive method to identify the ureter intraoperatively, which cannot be effectively achieved by traditional methods.
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Affiliation(s)
- Shan Wang
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Guorui Chen
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Bing Yao
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Adrian J Y Chee
- Schlegel Research Institute for Aging, University of Waterloo, Waterloo N2L 3G1, Canada
| | - Zongrong Wang
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Piyi Du
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Shaoxing Qu
- Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
| | - Alfred C H Yu
- Schlegel Research Institute for Aging, University of Waterloo, Waterloo N2L 3G1, Canada
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Chee AJY, Ishii T, Yiu BYS, Yu ACH. Helical toroid phantom for 3D flow imaging investigations. Phys Med Biol 2021; 66:045029. [PMID: 33586671 DOI: 10.1088/1361-6560/abda99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The medical physics community has hitherto lacked an effective calibration phantom to holistically evaluate the performance of three-dimensional (3D) flow imaging techniques. Here, we present the design of a new omnidirectional, three-component (3-C) flow phantom whose lumen is consisted of a helical toroid structure (4 mm lumen diameter; helically winded for 5 revolutions over a torus with 10 mm radius; 5 mm helix radius). This phantom's intraluminal flow trajectory embraces all combinations of x, y, and z directional components, as confirmed using computational fluid dynamics (CFD) simulations. The phantom was physically fabricated via lost-core casting with polyvinyl alcohol cryogel (PVA) as the tissue mimic. 3D ultrasound confirmed that the phantom lumen expectedly resembled a helical toroid geometry. Pulsed Doppler measurements showed that the phantom, when operating under steady flow conditions (3 ml s-1 flow rate), yielded flow velocity magnitudes that agreed well with those derived from CFD at both the inner torus (-47.6 ± 5.7 versus -52.0 ± 2.2 cm s-1; mean ± 1 S.D.) and the outer torus (49.5 ± 4.2 versus 48.0 ± 1.7 cm s-1). Additionally, 3-C velocity vectors acquired from multi-angle pulsed Doppler showed good agreement with CFD-derived velocity vectors (<7% and 10° difference in magnitude and flow angle, respectively). Ultrasound color flow imaging further revealed that the phantom's axial flow pattern was aligned with the CFD-derived flow profile. Overall, the helical toroid phantom has strong potential as an investigative tool in 3D flow imaging innovation endeavors, such as the development of flow vector estimators and visualization algorithms.
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Affiliation(s)
- Adrian J Y Chee
- Schlegel Research Institute for Aging and Department of Electrical and Computer Engineering, University of Waterloo, Waterloo ON, Canada
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Bernal M, Saldarriaga J, Cabeza C, Negreira C, Bustamante J, Brum J. Development and evaluation of anisotropic and nonlinear aortic models made from clinical images for in vitro experimentation. ACTA ACUST UNITED AC 2019; 64:165006. [DOI: 10.1088/1361-6560/ab2db5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Ishii T, Ho CK, Nahas H, Yiu BYS, Chee AJY, Yu ACH. Deformable phantoms of the prostatic urinary tract for urodynamic investigations. Med Phys 2019; 46:3034-3043. [PMID: 31049993 DOI: 10.1002/mp.13558] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/03/2019] [Accepted: 04/23/2019] [Indexed: 01/20/2023] Open
Abstract
PURPOSE Assessment of urethral dynamics is clinically regarded to be important in analyzing the functional impact of pathological features like urethral obstruction, albeit it is difficult to perform directly in vivo. To facilitate such an assessment, urethra phantoms may serve well as investigative tools by reconstructing urethral dynamics based on anthropomorphic factors. Here, our aim is to design a new class of anatomically realistic, deformable urethra phantoms that can simulate the geometric, mechanical, and hydrodynamic characteristics of the male prostatic urethra. METHODS A new lost-core tube casting protocol was devised. It first involved the drafting of urethra geometry in computer-aided design software. Next, 3D printing was used to fabricate the urethra geometry and an outer mold. These parts were then used to cast a urinary tract using a polyvinyl alcohol (PVA)-based material (with 26.6 ± 4.0 kPa Young's elastic modulus). After forming a surrounding tissue-mimicking slab using an agar-gelatin mixture (with 17.4 ± 3.4 kPa Young's modulus), the completed urethra phantom was connected to a flow circuit that simulates voiding. To assess the fabricated phantoms' morphology, ultrasound imaging was performed over different planes. Also, color Doppler imaging was performed to visualize the flow profile within the urinary tract. RESULTS Deformable phantoms were devised for the normal urethra and a diseased urethra with obstruction due to benign prostatic hyperplasia (BPH). During voiding, the short-axis lumen diameter at the verumontanum of the BPH-featured phantom (0.91 ± 0.08 mm) was significantly smaller than that for the normal phantom (2.49 ± 0.20 mm). Also, the maximum flow velocity of the BPH-featured phantom (59.3 ± 5.8 cm/s; without Doppler angle correction) was found to be higher than that of the normal phantom (22.7 ± 9.0 cm/s). CONCLUSION The fabricated phantoms were effective in simulating urethra deformation resulting from urine passage during voiding. They can be used for mechanistic studies of urethral dynamics and for the testing of urodynamic diagnostic techniques in urology.
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Affiliation(s)
- Takuro Ishii
- Research Institute for Aging and Department of Electrical & Computer Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Chung Kit Ho
- Research Institute for Aging and Department of Electrical & Computer Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Hassan Nahas
- Research Institute for Aging and Department of Electrical & Computer Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Billy Y S Yiu
- Research Institute for Aging and Department of Electrical & Computer Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Adrian J Y Chee
- Research Institute for Aging and Department of Electrical & Computer Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Alfred C H Yu
- Research Institute for Aging and Department of Electrical & Computer Engineering, University of Waterloo, Waterloo, ON, Canada
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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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