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Karimpour P, Ferizoli R, May JM, Kyriacou PA. Customisable Silicone Vessels and Tissue Phantoms for In Vitro Photoplethysmography Investigations into Cardiovascular Disease. Sensors (Basel) 2024; 24:1681. [PMID: 38475217 DOI: 10.3390/s24051681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 02/23/2024] [Accepted: 03/02/2024] [Indexed: 03/14/2024]
Abstract
Age-related vessel deterioration leads to changes in the structure and function of the heart and blood vessels, notably stiffening of vessel walls, increasing the risk of developing cardiovascular disease (CVD), which accounts for 17.9 million global deaths annually. This study describes the fabrication of custom-made silicon vessels with varying mechanical properties (arterial stiffness). The primary objective of this study was to explore how changes in silicone formulations influenced vessel properties and their correlation with features extracted from signals obtained from photoplethysmography (PPG) reflectance sensors in an in vitro setting. Through alterations in the silicone formulations, it was found that it is possible to create elastomers exhibiting an elasticity range of 0.2 MPa to 1.22 MPa. It was observed that altering vessel elasticity significantly impacted PPG signal morphology, particularly reducing amplitude with increasing vessel stiffness (p < 0.001). A p-value of 5.176 × 10-15 and 1.831 × 10-14 was reported in the red and infrared signals, respectively. It has been concluded in this study that a femoral artery can be recreated using the silicone material, with the addition of a softener to achieve the required mechanical properties. This research lays the foundation for future studies to replicate healthy and unhealthy vascular systems. Additional pathologies can be introduced by carefully adjusting the elastomer materials or incorporating geometrical features consistent with various CVDs.
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Affiliation(s)
- Parmis Karimpour
- Research Centre for Biomedical Engineering, City, University of London, London EC1V 0HB, UK
| | - Redjan Ferizoli
- Research Centre for Biomedical Engineering, City, University of London, London EC1V 0HB, UK
| | - James M May
- Research Centre for Biomedical Engineering, City, University of London, London EC1V 0HB, UK
| | - Panicos A Kyriacou
- Research Centre for Biomedical Engineering, City, University of London, London EC1V 0HB, UK
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Avital G, Hernandez Torres SI, Knowlton ZJ, Bedolla C, Salinas J, Snider EJ. Toward Smart, Automated Junctional Tourniquets-AI Models to Interpret Vessel Occlusion at Physiological Pressure Points. Bioengineering (Basel) 2024; 11:109. [PMID: 38391595 PMCID: PMC10885917 DOI: 10.3390/bioengineering11020109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/05/2024] [Accepted: 01/18/2024] [Indexed: 02/24/2024] Open
Abstract
Hemorrhage is the leading cause of preventable death in both civilian and military medicine. Junctional hemorrhages are especially difficult to manage since traditional tourniquet placement is often not possible. Ultrasound can be used to visualize and guide the caretaker to apply pressure at physiological pressure points to stop hemorrhage. However, this process is technically challenging, requiring the vessel to be properly positioned over rigid boney surfaces and applying sufficient pressure to maintain proper occlusion. As a first step toward automating this life-saving intervention, we demonstrate an artificial intelligence algorithm that classifies a vessel as patent or occluded, which can guide a user to apply the appropriate pressure required to stop flow. Neural network models were trained using images captured from a custom tissue-mimicking phantom and an ex vivo swine model of the inguinal region, as pressure was applied using an ultrasound probe with and without color Doppler overlays. Using these images, we developed an image classification algorithm suitable for the determination of patency or occlusion in an ultrasound image containing color Doppler overlay. Separate AI models for both test platforms were able to accurately detect occlusion status in test-image sets to more than 93% accuracy. In conclusion, this methodology can be utilized for guiding and monitoring proper vessel occlusion, which, when combined with automated actuation and other AI models, can allow for automated junctional tourniquet application.
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Affiliation(s)
- Guy Avital
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
- Israel Defense Forces Medical Corps, Ramat Gan 52620, Israel
- Division of Anesthesia, Intensive Care, and Pain Management, Tel-Aviv Medical Center, Affiliated with the Faculty of Medicine, Tel Aviv University, Tel Aviv 64239, Israel
| | | | - Zechariah J Knowlton
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Carlos Bedolla
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Jose Salinas
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Eric J Snider
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
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Hernandez-Torres SI, Bedolla C, Berard D, Snider EJ. An extended focused assessment with sonography in trauma ultrasound tissue-mimicking phantom for developing automated diagnostic technologies. Front Bioeng Biotechnol 2023; 11:1244616. [PMID: 38033814 PMCID: PMC10682760 DOI: 10.3389/fbioe.2023.1244616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Introduction: Medical imaging-based triage is critical for ensuring medical treatment is timely and prioritized. However, without proper image collection and interpretation, triage decisions can be hard to make. While automation approaches can enhance these triage applications, tissue phantoms must be developed to train and mature these novel technologies. Here, we have developed a tissue phantom modeling the ultrasound views imaged during the enhanced focused assessment with sonography in trauma exam (eFAST). Methods: The tissue phantom utilized synthetic clear ballistic gel with carveouts in the abdomen and rib cage corresponding to the various eFAST scan points. Various approaches were taken to simulate proper physiology without injuries present or to mimic pneumothorax, hemothorax, or abdominal hemorrhage at multiple locations in the torso. Multiple ultrasound imaging systems were used to acquire ultrasound scans with or without injury present and were used to train deep learning image classification predictive models. Results: Performance of the artificial intelligent (AI) models trained in this study achieved over 97% accuracy for each eFAST scan site. We used a previously trained AI model for pneumothorax which achieved 74% accuracy in blind predictions for images collected with the novel eFAST tissue phantom. Grad-CAM heat map overlays for the predictions identified that the AI models were tracking the area of interest for each scan point in the tissue phantom. Discussion: Overall, the eFAST tissue phantom ultrasound scans resembled human images and were successful in training AI models. Tissue phantoms are critical first steps in troubleshooting and developing medical imaging automation technologies for this application that can accelerate the widespread use of ultrasound imaging for emergency triage.
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Affiliation(s)
| | | | | | - Eric J. Snider
- Organ Support and Automation Technologies Group, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX, United States
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Drapal V, Mosier S, Norman A, Berbel G, Robinson JL, Friis EA. A preliminary In Vitro viability study of an electrically active hernia mesh on mouse fibroblasts. J Biomater Appl 2023; 38:662-669. [PMID: 37862784 DOI: 10.1177/08853282231209312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
Hernias occur when part of an organ, typically the intestines, protrudes through a disruption of the fascia in the abdominal wall, leading to patient pain, discomfort, and surgical intervention. Over one million hernia repair surgeries occur annually in the USA, but globally, hernia surgeries can exceed 20 million. Standard practice includes hernia repair mesh to help hold the compromised tissue together, depending on where the fascial disruption is located and the patient's condition. However, the recurrence rate for hernias after using the most common type of hernia mesh, synthetic, is currently high. Physiological-level electrical stimulation (ES) has shown beneficial effects in improving healing in soft tissue regeneration. Piezoelectric materials can produce low-level electrical signals from mechanical loading to help speed healing. Combining the novelty of piezo elements to create an electrically active hernia repair mesh for faster healing prospects is explored in this study through simulated transcutaneous mechanical loading of the piezo element with therapeutic ultrasound. A tissue phantom was developed using Gelatin #0 and Metamucil® to better simulate a clinical application of the therapeutic ultrasound loading modality. The cellular viability of varying ultrasound intensities and temporal effects was analyzed. Overall, minimal cytotoxicity was observed across all experimental groups during the ultrasound intensity and temporal viability studies.
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Affiliation(s)
- Victoria Drapal
- Bioengineering Graduate Program, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Savannah Mosier
- Bioengineering Graduate Program, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Anna Norman
- Bioengineering Graduate Program, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - German Berbel
- Department of Surgery, University of Kansas Medical Center, Kansas, KS, USA
| | - Jennifer L Robinson
- Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA, USA
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | - Elizabeth A Friis
- Bioengineering Graduate Program, School of Engineering, University of Kansas, Lawrence, KS, USA
- Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA
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Zhao M, Zhou M, Cao X, Feng J, Pogue BW, Paulsen KD, Jiang S. Stable tissue-mimicking phantoms for longitudinal multimodality imaging studies that incorporate optical, CT, and MRI contrast. J Biomed Opt 2023; 28:046006. [PMID: 37091909 PMCID: PMC10118137 DOI: 10.1117/1.jbo.28.4.046006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/30/2023] [Indexed: 05/03/2023]
Abstract
Significance Tissue phantoms that mimic the optical and radiologic properties of human or animal tissue play an important role in the development, characterization, and evaluation of imaging systems. Phantoms that are easily produced and stable for longitudinal studies are highly desirable. Aim A new type of long-lasting phantom was developed with commercially available materials and was assessed for fabrication ease, stability, and optical property control. Magnetic resonance imaging (MRI) and x-ray computed tomography (CT) contrast properties were also evaluated. Approach A systematic investigation of relationships between concentrations of skin-like pigments and composite optical properties was conducted to realize optical property phantoms in the red and near-infrared (NIR) wavelength range that also offered contrast for CT and MRI. Results Phantom fabrication time was < 1 h and did not involve any heating or cooling processes. Changes in optical properties were < 2 % over a 12-month period. Phantom optical and spectral features were similar to human soft tissue over the red to NIR wavelength ranges. Pigments used in the study also had CT and MRI contrasts for multimodality imaging studies. Conclusions The phantoms described here mimic optical properties of soft tissue and are suitable for multimodality imaging studies involving CT or MRI without adding secondary contrast agents.
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Affiliation(s)
- Mengyang Zhao
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
| | - Mingwei Zhou
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
| | - Xu Cao
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
| | - Jinchao Feng
- Beijing University of Technology, Beijing Key Laboratory of Computational Intelligence and Intelligent System, Faculty of Information Technology, Beijing, China
| | - Brian W. Pogue
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
| | - Keith D. Paulsen
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
| | - Shudong Jiang
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
- Address all correspondence to Shudong Jiang,
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Abstract
Significance For the development and routine characterization of optical devices used in medicine, tissue-equivalent phantoms mimicking a broad spectrum of human skin properties are indispensable. Aim Our work aims to develop a tissue-equivalent phantom suitable for photoplethysmography applications. The phantom includes the optical and mechanical properties of the three uppermost human skin layers (dermis, epidermis, and hypodermis, each containing different types of blood vessels) plus the ability to mimic pulsation. Approach While the mechanical properties of the polydimethylsiloxane base material are adjusted by different mixing ratios of a base and curing agent, the optical properties are tuned by adding titanium dioxide particles, India ink, and synthetic melanin in different concentrations. The layered structure of the phantom is realized using a doctor blade technique, and blood vessels are fabricated using molding wires of different diameters. The tissue-mimicking phantom is then integrated into an artificial circulatory system employing piezo-actuated double diaphragm pumps for testing. Results The optical and mechanical properties of human skin were successfully replicated. The diameter of the artificial blood vessels is linearly dependent on pump actuation, and the time-dependent expansion profile of real pulse forms were mimicked. Conclusions A tissue equivalent phantom suitable for the ex-vivo testing of opto-medical devices was demonstrated.
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Affiliation(s)
- Sophie Jenne
- University of Freiburg, Department of Microsystems Engineering—IMTEK, Gisela and Erwin Sick Chair of Micro-Optics, Freiburg, Germany
- Address all correspondence to Sophie Jenne,
| | - Hans Zappe
- University of Freiburg, Department of Microsystems Engineering—IMTEK, Gisela and Erwin Sick Chair of Micro-Optics, Freiburg, Germany
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Kuzemchak BC, Choe RH, Sherry M, Porter E, Fisher JP. 3D printable phantom for mimicking electrical properties of dermal tissue. J Biomed Mater Res A 2023; 111:884-895. [PMID: 36815502 DOI: 10.1002/jbm.a.37516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/24/2023]
Abstract
Skin cancer is one of the most ubiquitous forms of cancer that is often overdiagnosed or missed by traditional diagnostic techniques. Bioimpedance spectroscopy (BIS) is a technology that aims to take advantage of the variations in electrical properties of tissue to identify ectopic formations. It is difficult to develop BIS technologies without obtaining tumor tissue samples. One solution is to use a "tissue phantom," a synthetic structure that mimics the properties of tissue. Current solutions using natural biomaterials, such as gelatin, have not been able to create complex tissue geometries that are vital to honing BIS diagnostics. However, semi-synthetic polymers, such has gelatin methacrylate (GelMA), offer the benefits of possessing similar electrical properties to their respective source biomaterial while being 3D printable. In this work, we first measured the impedance of porcine dermal tissue. We then applied these impedance measurements to create an electrically accurate tissue phantom using a photocurable hydrogel, GelMA, and varying concentrations of NaCl, aluminum powder, and titanium dioxide powder.
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Affiliation(s)
- Blake C Kuzemchak
- Tissue Engineering & Biomaterials Laboratory, Fischell Department of Bioengineering, A. James Clark School of Engineering, University of Maryland, College Park, Maryland, USA.,Center for Engineering Complex Tissues, University of Maryland, College Park, Maryland, USA
| | - Robert H Choe
- Tissue Engineering & Biomaterials Laboratory, Fischell Department of Bioengineering, A. James Clark School of Engineering, University of Maryland, College Park, Maryland, USA.,Center for Engineering Complex Tissues, University of Maryland, College Park, Maryland, USA
| | - Mary Sherry
- Tissue Engineering & Biomaterials Laboratory, Fischell Department of Bioengineering, A. James Clark School of Engineering, University of Maryland, College Park, Maryland, USA.,Center for Engineering Complex Tissues, University of Maryland, College Park, Maryland, USA
| | - Emily Porter
- Chandra Family Department of Electrical and Computer Engineering, University of Texas, Austin, Texas, USA
| | - John P Fisher
- Tissue Engineering & Biomaterials Laboratory, Fischell Department of Bioengineering, A. James Clark School of Engineering, University of Maryland, College Park, Maryland, USA.,Center for Engineering Complex Tissues, University of Maryland, College Park, Maryland, USA
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Abstract
Optical tissue phantoms present substantial value for medical imaging and therapeutic applications. We have developed an epidermal tissue phantom to mimic the optical properties of human skin from the ultraviolet to the infrared region, exceeding the breadth of existing studies. An epoxy matrix is combined with melanin-mimicking polydopamine via a cost-effective fabrication strategy. Reflectance and transmittance measurements enable calculation of the wavelength-dependent complex refractive index and absorption coefficient. Results are compared with literature data to establish agreement with a real human epidermis. By analyzing emissive power at a typical skin temperature, the epidermal tissue phantom is shown to accurately mimic the radiative properties of human skin. This simple, multifunctional material represents a promising substitute for human tissue for a variety of medical and bioengineering applications.
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Affiliation(s)
- Andrew Caratenuto
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts02115, United States
| | - Su Li
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts02115, United States
| | - Yinsheng Wan
- Department of Biology, Providence College, Providence, Rhode Island02918, United States
| | - Yi Zheng
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts02115, United States.,Department of Chemical Engineering, Northeastern University, Boston, Massachusetts02115, United States
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Hernandez-Torres SI, Boice EN, Snider EJ. Using an Ultrasound Tissue Phantom Model for Hybrid Training of Deep Learning Models for Shrapnel Detection. J Imaging 2022; 8:270. [PMID: 36286364 DOI: 10.3390/jimaging8100270] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/04/2022] Open
Abstract
Tissue phantoms are important for medical research to reduce the use of animal or human tissue when testing or troubleshooting new devices or technology. Development of machine-learning detection tools that rely on large ultrasound imaging data sets can potentially be streamlined with high quality phantoms that closely mimic important features of biological tissue. Here, we demonstrate how an ultrasound-compliant tissue phantom comprised of multiple layers of gelatin to mimic bone, fat, and muscle tissue types can be used for machine-learning training. This tissue phantom has a heterogeneous composition to introduce tissue level complexity and subject variability in the tissue phantom. Various shrapnel types were inserted into the phantom for ultrasound imaging to supplement swine shrapnel image sets captured for applications such as deep learning algorithms. With a previously developed shrapnel detection algorithm, blind swine test image accuracy reached more than 95% accuracy when training was comprised of 75% tissue phantom images, with the rest being swine images. For comparison, a conventional MobileNetv2 deep learning model was trained with the same training image set and achieved over 90% accuracy in swine predictions. Overall, the tissue phantom demonstrated high performance for developing deep learning models for ultrasound image classification.
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Snider EJ, Hernandez-Torres SI, Avital G, Boice EN. Evaluation of an Object Detection Algorithm for Shrapnel and Development of a Triage Tool to Determine Injury Severity. J Imaging 2022; 8:jimaging8090252. [PMID: 36135417 PMCID: PMC9501864 DOI: 10.3390/jimaging8090252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/07/2022] [Accepted: 09/12/2022] [Indexed: 01/25/2023] Open
Abstract
Emergency medicine in austere environments rely on ultrasound imaging as an essential diagnostic tool. Without extensive training, identifying abnormalities such as shrapnel embedded in tissue, is challenging. Medical professionals with appropriate expertise are limited in resource-constrained environments. Incorporating artificial intelligence models to aid the interpretation can reduce the skill gap, enabling identification of shrapnel, and its proximity to important anatomical features for improved medical treatment. Here, we apply a deep learning object detection framework, YOLOv3, for shrapnel detection in various sizes and locations with respect to a neurovascular bundle. Ultrasound images were collected in a tissue phantom containing shrapnel, vein, artery, and nerve features. The YOLOv3 framework, classifies the object types and identifies the location. In the testing dataset, the model was successful at identifying each object class, with a mean Intersection over Union and average precision of 0.73 and 0.94, respectively. Furthermore, a triage tool was developed to quantify shrapnel distance from neurovascular features that could notify the end user when a proximity threshold is surpassed, and, thus, may warrant evacuation or surgical intervention. Overall, object detection models such as this will be vital to compensate for lack of expertise in ultrasound interpretation, increasing its availability for emergency and military medicine.
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Affiliation(s)
- Eric J. Snider
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | | | - Guy Avital
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
- Trauma & Combat Medicine Branch, Surgeon General’s Headquarters, Israel Defense Forces, Ramat-Gan 52620, Israel
- Division of Anesthesia, Intensive Care & Pain Management, Tel-Aviv Sourasky Medical Center, Affiliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv 64239, Israel
| | - Emily N. Boice
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
- Correspondence: ; Tel.: +1-210-539-8721
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Boice EN, Hernandez Torres SI, Knowlton ZJ, Berard D, Gonzalez JM, Avital G, Snider EJ. Training Ultrasound Image Classification Deep-Learning Algorithms for Pneumothorax Detection Using a Synthetic Tissue Phantom Apparatus. J Imaging 2022; 8:jimaging8090249. [PMID: 36135414 PMCID: PMC9502699 DOI: 10.3390/jimaging8090249] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/20/2022] [Accepted: 09/07/2022] [Indexed: 11/17/2022] Open
Abstract
Ultrasound (US) imaging is a critical tool in emergency and military medicine because of its portability and immediate nature. However, proper image interpretation requires skill, limiting its utility in remote applications for conditions such as pneumothorax (PTX) which requires rapid intervention. Artificial intelligence has the potential to automate ultrasound image analysis for various pathophysiological conditions. Training models require large data sets and a means of troubleshooting in real-time for ultrasound integration deployment, and they also require large animal models or clinical testing. Here, we detail the development of a dynamic synthetic tissue phantom model for PTX and its use in training image classification algorithms. The model comprises a synthetic gelatin phantom cast in a custom 3D-printed rib mold and a lung mimicking phantom. When compared to PTX images acquired in swine, images from the phantom were similar in both PTX negative and positive mimicking scenarios. We then used a deep learning image classification algorithm, which we previously developed for shrapnel detection, to accurately predict the presence of PTX in swine images by only training on phantom image sets, highlighting the utility for a tissue phantom for AI applications.
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Affiliation(s)
- Emily N. Boice
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | | | - Zechariah J. Knowlton
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - David Berard
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Jose M. Gonzalez
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Guy Avital
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
- Trauma & Combat Medicine Branch, Surgeon General’s Headquarters, Israel Defense Forces, Ramat-Gan 52620, Israel
- Division of Anesthesia, Intensive Care & Pain Management, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv 64239, Israel
| | - Eric J. Snider
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
- Correspondence: ; Tel.: +210-539-8721
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Yu Y, Anand G, Lowe A, Zhang H, Kalra A. Towards Estimating Arterial Diameter Using Bioimpedance Spectroscopy: A Computational Simulation and Tissue Phantom Analysis. Sensors (Basel) 2022; 22:4736. [PMID: 35808233 PMCID: PMC9268936 DOI: 10.3390/s22134736] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
This paper improves the accuracy of quantification in the arterial diameter-dependent impedance variance by altering the electrode configuration. The finite element analysis was implemented with a 3D human wrist fragment using ANSYS Electronics Desktop, containing fat, muscle, and a blood-filled radial artery. Then, the skin layer and bones were stepwise added, helping to understand the dielectric response of multi-tissues and blood flow from 1 kHz to 1 MHz, the current distribution throughout the wrist, and the optimisation of electrode configurations for arterial pulse sensing. Moreover, a low-cost wrist phantom was fabricated, containing two components: the surrounding tissue simulant (20 wt % gelatine power and 0.017 M sodium chloride (NaCl) solution) and the blood simulant (0.08 M NaCl solution). The blood-filled artery was constricted using a desktop injection pump, and the impedance change was measured by the Multi-frequency Impedance Analyser (MFIA). The simulation revealed the promising capabilities of band electrodes to generate a more uniform current distribution than the traditional spot electrodes. Both simulation and phantom experimental results indicated that a longer spacing between current-carrying (CC) electrodes with shorter spacing between pick-up (PU) electrodes in the middle could sense a more uniform electric field, engendering a more accurate arterial diameter estimation. This work provided an improved electrode configuration for more accurate arterial diameter estimation from the numerical simulation and tissue phantom perspectives.
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Abstract
OBJECTIVE To develop a robotic phantom system containing multiple simulated wound replicates to determine the synergy in fluid absorbency and retention (sorptivity) performances and the post-simulated-use mechanical durability of silver-containing gelling fiber primary dressings when used with a secondary dressing, as per clinical practice. METHODS Using a robotic system containing six identical wound simulators, the authors tested the sorptivity performances of the Exufiber Ag + (Mölnlycke Health Care, Gothenburg, Sweden) primary dressing (ExAg-polyvinyl alcohol [PVA]) against a market-leading comparator product, when used with a secondary foam dressing. The durability of the primary dressings after simulated use was further investigated through tensile mechanical testing. RESULTS The ExAg-PVA primary dressing delivered greater fluid amounts for absorbency and retention by the secondary foam dressing, approximately 2- and 1.5-fold more than the comparator dressing pair after 10 and 15 hours, respectively. The ExAg-PVA dressing was also substantially less sensitive to the direction of pulling forces and, accordingly, exhibited post-use mechanical strength that was approximately four and six times greater than that of the other primary dressing (when the latter dressing was tested out-of-alignment with its visible seams) after 10 and 15 hours, respectively. CONCLUSIONS The dynamics of the sorptivity and fluid sharing between primary and secondary dressings and the effect of directional preference of strength of the primary dressings for adequate durability, resulting in safe post-use removals, have been described. The comparative quantification of these capabilities should help clinical and nonclinical decision-makers select dressings that best meet their patient needs.
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Affiliation(s)
- Aleksei Orlov
- At Tel Aviv University, Department of Biomedical Engineering, Tel Aviv, Israel, Aleksei Orlov, MSc; Adi Lustig, MSc; and Angela Grigatti, MSc, are Graduate Students at the research group of Professor Gefen; and Amit Gefen, PhD, is Professor of Biomedical Engineering and the Herbert J. Berman Chair in Vascular Bioengineering. Acknowledgment: This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 811965; project STINTS (Skin Tissue Integrity under Shear). This work was also partially supported by the Israeli Ministry of Science & Technology (Medical Devices Program grant no. 3-17421, awarded to Prof Amit Gefen in 2020) and by Mölnlycke Health Care (Gothenburg, Sweden). The authors thank Ms Orel Belo, the Laboratory Engineer at the Gefen Laboratory, for supporting the experimental work. The authors have disclosed no other financial relationships related to this article. Submitted July 23, 2021; accepted in revised form November 1, 2021; published online ahead of print March 14, 2022
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Orlov A, Gefen A. The fluid handling performance of the curea P1 multipurpose dressing against superabsorbent and foam dressing technologies. Int Wound J 2022; 19:945-956. [PMID: 35254730 PMCID: PMC9013594 DOI: 10.1111/iwj.13774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 01/18/2023] Open
Abstract
Using a novel, automated robotic phantom system containing multiple wound simulants, we determined the fluid handling performance of the curea P1 multipurpose dressing vs market‐leading comparator superabsorbent and foam‐based dressings (FBDs). Specifically, we measured the retained, residual, evaporated, and (potentially occurring) spillover fluid shares for high‐ vs low‐viscosity exudate‐simulant test fluids, at 12, 24, and 30 hours postapplication of the dressings. These experiments were conducted for off‐loaded (‘prone’), non‐off‐loaded (‘supine’), and vertical (‘side‐lying’) simulated body positions. We found that the multipurpose dressing exhibited the best and most robust fluid handling performance across all the test configurations, for both the low‐ and high‐viscosity fluids. The FBD consistently showed the poorest performance compared to the other dressings, rendering it unlikely to be able to manage viscous exudates in ambulant patients (such as when applied to venous leg ulcers) as effectively as the other dressings. The superabsorbent dressing performed better than the foam dressing, but its fluid handling metrics were inferior to those of the multipurpose dressing. The current comparative quantification of the shares of retained, residual, evaporated, and spillover fluid, acquired through standardised laboratory tests, should help decision‐makers to select dressings that best meet their patient needs.
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Affiliation(s)
- Aleksei Orlov
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Amit Gefen
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
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15
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Hada AM, Craciun AM, Astilean S. Intrinsic Photoluminescence of Solid-State Gold Nanoclusters: Towards Fluorescence Lifetime Imaging of Tissue-Like Phantoms Under Two-Photon Near-Infrared Excitation. Front Chem 2021; 9:761711. [PMID: 34746095 PMCID: PMC8566988 DOI: 10.3389/fchem.2021.761711] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/01/2021] [Indexed: 11/23/2022] Open
Abstract
Gold nanoclusters (AuNCs) have attracted extensive attention as light-emissive materials with unique advantages such as high photostability, large Stoke shifts and low toxicity. However, a better understanding of their solid-state photoluminescence properties is still needed. Herein, we investigated for the first time the intrinsic photoluminescence properties of lyophilized bovine serum albumin stabilized AuNCs (BSA-AuNCs) via fluorescence lifetime imaging microscopy (FLIM) studies performed under both one and two photon excitations (OPE and TPE) on individual microflakes, combined with fluorescence spectroscopic investigations. Both in solution and solid-state, the synthesized BSA-AuNCs exhibit photoluminescence in the first biological window with an absolute quantum yield of 6% and high photostability under continuous irradiation. Moreover, under both OPE and TPE conditions, solid BSA-AuNCs samples exhibited a low degree of photobleaching, while FLIM assays prove the homogeneous distribution of the photoluminescence signal inside the microflakes. Finally, we demonstrate the ability of BSA-AuNCs to perform as reliable bright and photostable contrast agents for the visualization of cancer tissue mimicking agarose-phantoms using FLIM approach under non-invasive TPE. Therefore, our results emphasize the great potential of the as synthesized BSA-AuNCs for ex vivo and in vivo non-invasive NIR imaging applications.
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Affiliation(s)
- Alexandru-Milentie Hada
- Nanobiophotonics and Laser Microspectroscopy Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, Cluj-Napoca, Romania
- Faculty of Physics, Babes-Bolyai University, Cluj-Napoca, Romania
| | - Ana-Maria Craciun
- Nanobiophotonics and Laser Microspectroscopy Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, Cluj-Napoca, Romania
| | - Simion Astilean
- Nanobiophotonics and Laser Microspectroscopy Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, Cluj-Napoca, Romania
- Faculty of Physics, Babes-Bolyai University, Cluj-Napoca, Romania
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16
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Rogelj L, Simončič U, Tomanič T, Jezeršek M, Pavlovčič U, Stergar J, Milanič M. Effect of curvature correction on parameters extracted from hyperspectral images. J Biomed Opt 2021; 26:JBO-210189R. [PMID: 34490762 PMCID: PMC8420878 DOI: 10.1117/1.jbo.26.9.096003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE Hyperspectral imaging (HSI) has emerged as a promising optical technique. Besides optical properties of a sample, other sample physical properties also affect the recorded images. They are significantly affected by the sample curvature and sample surface to camera distance. A correction method to reduce the artifacts is necessary to reliably extract sample properties. AIM Our aim is to correct hyperspectral images using the three-dimensional (3D) surface data and assess how the correction affects the extracted sample properties. APPROACH We propose the combination of HSI and 3D profilometry to correct the images using the Lambert cosine law. The feasibility of the correction method is presented first on hemispherical tissue phantoms and next on human hands before, during, and after the vascular occlusion test (VOT). RESULTS Seven different phantoms with known optical properties were created and imaged with a hyperspectral system. The correction method worked up to 60 deg inclination angle, whereas for uncorrected images the maximum angles were 20 deg. Imaging hands before, during, and after VOT shows good agreement between the expected and extracted skin physiological parameters. CONCLUSIONS The correction method was successfully applied on the images of tissue phantoms of known optical properties and geometry and VOT. The proposed method could be applied to any reflectance optical imaging technique and should be used whenever the sample parameters need to be extracted from a curved surface sample.
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Affiliation(s)
- Luka Rogelj
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Urban Simončič
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
- Jozef Stefan Institute, Ljubljana, Slovenia
| | - Tadej Tomanič
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Matija Jezeršek
- University of Ljubljana, Faculty of Mechanical Engineering, Ljubljana, Slovenia
| | - Urban Pavlovčič
- University of Ljubljana, Faculty of Mechanical Engineering, Ljubljana, Slovenia
| | | | - Matija Milanič
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
- Jozef Stefan Institute, Ljubljana, Slovenia
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17
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Krajnik B, Golacki LW, Fiedorczyk E, Bański M, Noculak A, Hołodnik KM, Podhorodecki A. Quantitative comparison of luminescence probes for biomedical applications. Methods Appl Fluoresc 2021; 9. [PMID: 34198274 DOI: 10.1088/2050-6120/ac10ae] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/01/2021] [Indexed: 12/30/2022]
Abstract
Optical imaging holds great promise for the early-stage detection of diseases. It plays an important role in the process of protecting the patient's health. Most of the organic dyes suffer due to photobleaching, light scattering, short light penetration depth, and autofluorescence of specimen, thus, need to be replaced with alternative nanoprobes emitting light in the optical biological window (700-1350 nm). The group of candidates which can challenged described problems are colloidal quantum dots (e.g. CdSe and PbS) and upconverting nanocrystals (e.g. NaGdF4:Er, Yb). This paper presents comprehensive and systematic studies of the aforementioned probes, using specially designed tissue phantom, and custom-built wide-field fluorescence microscope. We investigated how the absorption and scattering of light at the water, hemoglobin, and intralipid may affect the intensity of luminescence probes and the quality of optical images. We propose a protocol, that could be easily implemented for investigating other nanoprobes that allow for comparison of their optical performance.
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Affiliation(s)
- B Krajnik
- Department of Experimental Physics, Wroclaw University of Science and Technology, Wyb. S. Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - L W Golacki
- Department of Experimental Physics, Wroclaw University of Science and Technology, Wyb. S. Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - E Fiedorczyk
- Department of Experimental Physics, Wroclaw University of Science and Technology, Wyb. S. Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - M Bański
- Department of Experimental Physics, Wroclaw University of Science and Technology, Wyb. S. Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - A Noculak
- Department of Experimental Physics, Wroclaw University of Science and Technology, Wyb. S. Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - K M Hołodnik
- Department of Experimental Physics, Wroclaw University of Science and Technology, Wyb. S. Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - A Podhorodecki
- Department of Experimental Physics, Wroclaw University of Science and Technology, Wyb. S. Wyspiańskiego 27, 50-370 Wroclaw, Poland
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18
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Freymüller C, Kalinina S, Rück A, Sroka R, Rühm A. Quenched coumarin derivatives as fluorescence lifetime phantoms for NADH and FAD. J Biophotonics 2021; 14:e202100024. [PMID: 33749988 DOI: 10.1002/jbio.202100024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/22/2021] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Two-photon fluorescence lifetime imaging is a versatile laboratory technique in the field of biophotonics and its importance is also growing in the field of in vivo diagnostics for medical purposes. After years of experience in dermatology, endoscopic implementations of the technique are now posing new technical challenges. To develop, test, and compare instrumental solutions for this purpose suitable reference samples have been devised and tested. These reference samples can serve as reliable NADH- and FAD-mimicking optical phantoms for 2-photon fluorescence lifetime imaging, as they can be prepared relatively easily with reproducible and stable characteristics for this quite relevant diagnostic technique. The reference samples (mixtures of coumarin 1 and coumarin 6 in ethanol with suitable amounts of 4-hydroxy-TEMPO) have been tuned to exhibit spectral and temporal fluorescence characteristics very similar to those of NADH and FAD, the two molecules most frequently utilized to characterize cell metabolism.
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Affiliation(s)
- Christian Freymüller
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Sviatlana Kalinina
- Core Facility Confocal and Multiphoton Microscopy N24, University of Ulm, Ulm, Germany
| | - Angelika Rück
- Core Facility Confocal and Multiphoton Microscopy N24, University of Ulm, Ulm, Germany
| | - Ronald Sroka
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Adrian Rühm
- Laser-Forschungslabor, LIFE Center, University Hospital, LMU Munich, Planegg, Germany
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
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19
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Lustig A, Alves P, Call E, Santamaria N, Gefen A. The sorptivity and durability of gelling fibre dressings tested in a simulated sacral pressure ulcer system. Int Wound J 2020; 18:194-208. [PMID: 33236856 PMCID: PMC8243987 DOI: 10.1111/iwj.13515] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 10/03/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022] Open
Abstract
Wound‐dressing performances are affected by exudate viscosity, resistance to flow because of gravity, and bodyweight loads, the level of which is related to the body position. Here, we focussed on two dressing properties: (a) Sorptivity—the ability of dressings to transfer exudate away from the wound bed by capillary action—and (b) Durability—the capacity of dressings to maintain their integrity over time and during their removal. Both properties are critically important for avoiding further tissue damage but require the development of new laboratory tests for their measurement. A computer‐controlled phantom of an exuding sacral pressure ulcer has therefore been developed and used to compare the performances of Exufiber (Mölnlycke Health Care) vs an alternative market‐leading dressing. Sorptivity was determined using weight tests, and durability was measured through tensile tests of the used dressings. For a supine configuration, the Exufiber dressing demonstrated ~three times higher sorptivity and better durability, withstanding ~five times greater strain energy than the other product before failure occurred. This work paves the way for quantitative, standardised testing of dressings in all aspects of exudate management. The reported tests are further suitable for testing dressing combinations or how dressings interact with negative pressure wound therapy.
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Affiliation(s)
- Adi Lustig
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Paulo Alves
- Centre for Interdisciplinary Research in Health, Catholic University of Portugal, Porto, Portugal
| | - Evan Call
- Department of Microbiology, Weber State University, Ogden, Utah, USA
| | - Nick Santamaria
- School of Health Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Amit Gefen
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
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20
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Abstract
Recent advances in embedded three-dimensional (3D) bioprinting have expanded the design space for fabricating geometrically complex tissue scaffolds using hydrogels with mechanical properties comparable to native tissues and organs in the human body. The advantage of approaches such as Freeform Reversible Embedding of Suspended Hydrogels (FRESH) printing is the ability to embed soft biomaterials in a thermoreversible support bath at sizes ranging from a few millimeters to centimeters. In this study, we were able to expand this printable size range by FRESH bioprinting a full-size model of an adult human heart from patient-derived magnetic resonance imaging (MRI) data sets. We used alginate as the printing biomaterial to mimic the elastic modulus of cardiac tissue. In addition to achieving high print fidelity on a low-cost printer platform, FRESH-printed alginate proved to create mechanically tunable and suturable models. This demonstrates that large-scale 3D bioprinting of soft hydrogels is possible using FRESH and that cardiac tissue constructs can be produced with potential future applications in surgical training and planning.
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Affiliation(s)
- Eman Mirdamadi
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Joshua W Tashman
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Daniel J Shiwarski
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Rachelle N Palchesko
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Adam W Feinberg
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States.,Department of Materials Science & Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
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21
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Geoghegan R, Santamaria A, Priester A, Zhang L, Wu H, Grundfest W, Marks L, Natarajan S. A tissue-mimicking prostate phantom for 980 nm laser interstitial thermal therapy. Int J Hyperthermia 2020; 36:993-1002. [PMID: 31544549 DOI: 10.1080/02656736.2019.1660811] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Purpose: To develop a phantom with optical and thermal properties matched to human prostate. This phantom will provide a platform for the development and characterization of 980 nm laser interstitial thermal therapy (LITT) systems. Methods: A polyacrylamide gel was doped with Naphthol Green B, Intralipid, and Bovine Serum Albumin (BSA). The necessary concentration of each ingredient was determined by measuring the optical properties via fluence measurements and light diffusion theory. LITT was then performed under the same conditions as a previous clinical trial in which temperature was monitored via a thermal probe. The thermal data and induced coagulation zone were compared to clinical data to illustrate the similarity between the phantom and patient. LITT was also performed under magnetic resonance thermometry (MRT). Results: The requisite concentrations of Naphthol Green B, Intralipid and BSA were found to be 0.144% (w/v), 8.06% (v/v) and 31.4% (v/v) respectively. In the native state, the absorption coefficient and reduced scattering coefficient ( μs' ) were found to be 0.66 ± 0.06 cm-1 and 8.27 ± 0.50 cm-1 respectively, with μs' increasing to 17.63 ± 1.41 cm-1 after coagulation. The thermal response of the phantom was similar to that observed clinically with maximum thermal probe measurements of 64.2 °C and 66.9 °C respectively. The shape of the induced coagulation zone was qualitatively and quantitatively similar to the MRT zone of elevated temperature and the coagulation zone observed clinically. Conclusions: A phantom which simulates optical and thermal response to 980 nm LITT was constructed and demonstrated to be similar to human prostate.
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Affiliation(s)
- R Geoghegan
- Department of Bioengineering, University of California , Los Angeles , CA , USA
| | - A Santamaria
- Department of Urology, University of California , Los Angeles , CA , USA
| | - A Priester
- Department of Bioengineering, University of California , Los Angeles , CA , USA.,Department of Urology, University of California , Los Angeles , CA , USA
| | - L Zhang
- Department of Radiological Sciences, University of California , Los Angeles , CA , USA
| | - H Wu
- Department of Bioengineering, University of California , Los Angeles , CA , USA.,Department of Radiological Sciences, University of California , Los Angeles , CA , USA
| | - W Grundfest
- Department of Bioengineering, University of California , Los Angeles , CA , USA
| | - L Marks
- Department of Urology, University of California , Los Angeles , CA , USA
| | - S Natarajan
- Department of Bioengineering, University of California , Los Angeles , CA , USA.,Department of Urology, University of California , Los Angeles , CA , USA
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22
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Larsson J, Liao P, Lundin P, Krite Svanberg E, Swartling J, Lewander Xu M, Bood J, Andersson-Engels S. Development of a 3-dimensional tissue lung phantom of a preterm infant for optical measurements of oxygen-Laser-detector position considerations. J Biophotonics 2018; 11:e201700097. [PMID: 28816029 DOI: 10.1002/jbio.201700097] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/11/2017] [Accepted: 08/11/2017] [Indexed: 05/24/2023]
Abstract
There is a need to further improve the clinical care of our most vulnerable patients-preterm infants. Novel diagnostic and treatment tools facilitate such advances. Here, we evaluate a potential percutaneous optical monitoring tool to assess the oxygen and water vapor content in the lungs of preterm babies. The aim is to prepare for further clinical studies by gaining a detailed understanding of how the measured light intensity and gas absorption signal behave for different possible geometries of light delivery and receiver. Such an experimental evaluation is conducted for the first time utilizing a specially developed 3-dimensional-printed optical phantom based on a geometry model obtained from computer tomography images of the thorax (chest) of a 1700-g premature infant. The measurements yield reliable signals for source-detector distances up to about 50 mm, with stronger gas absorption signals at long separations and positions related to the lower part of the lung, consistent with a larger relative volume of this. The limitations of this study include the omission of scattering tissue within the lungs and that similar optical properties are used for the wavelengths employed for the 2 gases, yielding no indication on the optimal wavelength pair to use.
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Affiliation(s)
- Jim Larsson
- Division of Combustion Physics, Department of Physics, Lund University, Lund, Sweden
| | - Peilang Liao
- Department of Physics, Lund University, Lund, Sweden
- GASPOROX AB (publ), Lund, Sweden
| | - Patrik Lundin
- Department of Physics, Lund University, Lund, Sweden
- GASPOROX AB (publ), Lund, Sweden
| | - Emilie Krite Svanberg
- Department of Clinical Sciences, Anesthesiology and Intensive Care Medicine, Skåne University Hospital, Lund University, Lund, Sweden
- Lund Laser Centre, Lund University, Lund, Sweden
| | | | | | - Joakim Bood
- Division of Combustion Physics, Department of Physics, Lund University, Lund, Sweden
| | - Stefan Andersson-Engels
- Department of Physics, Lund University, Lund, Sweden
- IPIC, Tyndall National Institute, Lee Maltings, Cork, Ireland
- Department of Physics, University College Cork, Cork, Ireland
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23
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Nwafor CI, Plant KD, King DR, McCall BP, Squiers JJ, Fan W, DiMaio JM, Thatcher JE. Assessment of a noninvasive optical photoplethysmography imaging device with dynamic tissue phantom models. J Biomed Opt 2017; 22:1-9. [PMID: 28895317 DOI: 10.1117/1.jbo.22.9.096003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
Noncontact photoplethysmography (PPG) has been studied as a method to provide low-cost, noninvasive, two-dimensional blood oxygenation measurements and medical imaging for a variety of near-surface pathologies. To evaluate this technology in a laboratory setting, dynamic tissue phantoms were developed with tunable parameters that mimic physiologic properties of the skin, including blood vessel volume change, pulse wave frequency, and tissue scattering and absorption. Tissue phantoms were generated using an elastic tubing to represent a blood vessel where the luminal volume could be modulated with a pulsatile fluid flow. The blood was mimicked with a scattering and absorbing motility standard, and the tissue with a gelatin-lipid emulsion hydrogel. A noncontact PPG imaging system was then evaluated using the phantoms. Noncontact PPG imaging accurately identified pulse frequency, and PPG signals from these phantoms suggest that the phantoms can be used to evaluate noncontact PPG imaging systems. Such information may be valuable to the development of future PPG imaging systems.
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Affiliation(s)
| | | | | | | | - John J Squiers
- Spectral MD, Inc., Texas, United States
- Baylor University Medical Center, Department of Surgery, Texas, United States
- Baylor Research Institute, Baylor Scott and White Health, Texas, United States
| | | | - J Michael DiMaio
- Spectral MD, Inc., Texas, United States
- Baylor Research Institute, Baylor Scott and White Health, Texas, United States
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24
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O'Reilly JP, Kolodziejski NJ, McAdams D, Fernandez DE, Stapels CJ, Christian JF. A capillary-mimicking optical tissue phantom for diffuse correlation spectroscopy. Proc SPIE Int Soc Opt Eng 2017; 10056. [PMID: 29706681 DOI: 10.1117/12.2252498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Optical tissue phantoms are necessary for instrument benchmarking and providing a consistent baseline for experiments in various fields of tissue spectroscopy, including diffuse correlation spectroscopy (DCS). To provide the most useful comparisons, a phantom would ideally mimic tissue as closely as possible, including the geometry of static and dynamic scatterers. A branching design that keeps the capillary cross section constant ensures that the same flow velocity is found throughout the phantom while allowing for single input and output fittings to feed all of the capillaries simultaneously. The direction of each capillary is randomized every few millimeters by randomly allocating 2 by 2 "twisting" squares within each layer. These squares swap the locations of four adjacent artificial capillaries either clockwise or counterclockwise. Numerical simulations were used to verify the random walk-like behavior of the capillary paths resulting from this pattern. This is a step toward replicating the randomly varying directionality of actual capillaries. This design was verified by taking DCS measurements at different flow rates of Intralipid through the phantom, demonstrating the effect of the flow rate on the characteristic decay time of the autocorrelation.
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Affiliation(s)
- Jameson P O'Reilly
- Northeastern University, 360 Huntington Avenue, Boston, MA, USA 02115-5005.,Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA, USA 02472-4699
| | - Noah J Kolodziejski
- Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA, USA 02472-4699
| | - Daniel McAdams
- Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA, USA 02472-4699
| | - Daniel E Fernandez
- Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA, USA 02472-4699
| | | | - James F Christian
- Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA, USA 02472-4699
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25
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Chanda A, Unnikrishnan V, Flynn Z, Lackey K. Experimental study on tissue phantoms to understand the effect of injury and suturing on human skin mechanical properties. Proc Inst Mech Eng H 2016; 231:80-91. [PMID: 28097936 DOI: 10.1177/0954411916679438] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Skin injuries are the most common type of injuries occurring in day-to-day life. A skin injury usually manifests itself in the form of a wound or a cut. While a shallow wound may heal by itself within a short time, deep wounds require surgical interventions such as suturing for timely healing. To date, suturing practices are based on a surgeon's experience and may vary widely from one situation to another. Understanding the mechanics of wound closure and suturing of the skin is crucial to improve clinical suturing practices and also to plan automated robotic surgeries. In the literature, phenomenological two-dimensional computational skin models have been developed to study the mechanics of wound closure. Additionally, the effect of skin pre-stress (due to the natural tension of the skin) on wound closure mechanics has been studied. However, in most of these analyses, idealistic two-dimensional skin geometries, materials and loads have been assumed, which are far from reality, and would clearly generate inaccurate quantitative results. In this work, for the first time, a biofidelic human skin tissue phantom was developed using a two-part silicone material. A wound was created on the phantom material and sutures were placed to close the wound. Uniaxial mechanical tests were carried out on the phantom specimens to study the effect of varying wound size, quantity, suture and pre-stress on the mechanical behavior of human skin. Also, the average mechanical behavior of the human skin surrogate was characterized using hyperelastic material models, in the presence of a wound and sutures. To date, such a robust experimental study on the effect of injury and sutures on human skin mechanics has not been attempted. The results of this novel investigation will provide important guidelines for surgical planning and validation of results from computational models in the future.
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Affiliation(s)
- Arnab Chanda
- 1 Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa, AL, USA
| | - Vinu Unnikrishnan
- 1 Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa, AL, USA
| | - Zachary Flynn
- 2 Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL, USA
| | - Kim Lackey
- 3 Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
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Saager RB, Quach A, Rowland RA, Baldado ML, Durkin AJ. Low-cost tissue simulating phantoms with adjustable wavelength-dependent scattering properties in the visible and infrared ranges. J Biomed Opt 2016; 21:67001. [PMID: 27292135 PMCID: PMC4904063 DOI: 10.1117/1.jbo.21.6.067001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 05/23/2016] [Indexed: 05/09/2023]
Abstract
We present a method for low-cost fabrication of polydimethylsiloxane (PDMS) tissue simulating phantoms with tunable scattering spectra, spanning visible, and near-infrared regimes. These phantoms use optical polishing agents (aluminum oxide powders) at various grit sizes to approximate in vivo tissue scattering particles across multiple size distributions (range: 17 to 3 μm). This class of tunable scattering phantoms is used to mimic distinct changes in wavelength-dependent scattering properties observed in tissue pathologies such as partial thickness burns. Described by a power-law dependence on wavelength, the scattering magnitude of these phantoms scale linearly with particle concentration over a physiologic range [μs′=(0.5 to 2.0 mm−1)] whereas the scattering spectra, specific to each particle size distribution, correlate to distinct exponential coefficients (range: 0.007 to 0.32). Aluminum oxide powders used in this investigation did not detectably contribute to the absorption properties of these phantoms. The optical properties of these phantoms are verified through inverse adding-doubling methods and the tolerances of this fabrication method are discussed.
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Affiliation(s)
- Rolf B. Saager
- University of California, Irvine, 1002 Health Sciences Road, Irvine, California 92612, United States
- Address all correspondence to: Rolf B. Saager, E-mail:
| | - Alan Quach
- University of California, Irvine, 1002 Health Sciences Road, Irvine, California 92612, United States
| | - Rebecca A. Rowland
- University of California, Irvine, 1002 Health Sciences Road, Irvine, California 92612, United States
| | - Melissa L. Baldado
- University of California, Irvine, 1002 Health Sciences Road, Irvine, California 92612, United States
| | - Anthony J. Durkin
- University of California, Irvine, 1002 Health Sciences Road, Irvine, California 92612, United States
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Gurjar OP, Mishra SP, Bhandari V, Pathak P, Patel P, Shrivastav G. Radiation dose verification using real tissue phantom in modern radiotherapy techniques. J Med Phys 2014; 39:44-9. [PMID: 24600172 PMCID: PMC3931228 DOI: 10.4103/0971-6203.125504] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/31/2013] [Accepted: 10/31/2013] [Indexed: 11/04/2022] Open
Abstract
In vitro dosimetric verification prior to patient treatment has a key role in accurate and precision radiotherapy treatment delivery. Most of commercially available dosimetric phantoms have almost homogeneous density throughout their volume, while real interior of patient body has variable and varying densities inside. In this study an attempt has been made to verify the physical dosimetry in actual human body scenario by using goat head as "head phantom" and goat meat as "tissue phantom". The mean percentage variation between planned and measured doses was found to be 2.48 (standard deviation (SD): 0.74), 2.36 (SD: 0.77), 3.62 (SD: 1.05), and 3.31 (SD: 0.78) for three-dimensional conformal radiotherapy (3DCRT) (head phantom), intensity modulated radiotherapy (IMRT; head phantom), 3DCRT (tissue phantom), and IMRT (tissue phantom), respectively. Although percentage variations in case of head phantom were within tolerance limit (< ± 3%), but still it is higher than the results obtained by using commercially available phantoms. And the percentage variations in most of cases of tissue phantom were out of tolerance limit. On the basis of these preliminary results it is logical and rational to develop radiation dosimetry methods based on real human body and also to develop an artificial phantom which should truly represent the interior of human body.
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Affiliation(s)
- Om Prakash Gurjar
- , Department of Physics, Mewar University, Chittorgarh, Rajasthan ; , Roentgen-SAIMS Radiation Oncology Centre, Sri Aurobindo Institute of Medical Sciences, Indore, Madhya Pradesh, India
| | - S P Mishra
- Department of Radiotherapy, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India ; , Department of Physics, Mewar University, Chittorgarh, Rajasthan
| | - Virendra Bhandari
- , Roentgen-SAIMS Radiation Oncology Centre, Sri Aurobindo Institute of Medical Sciences, Indore, Madhya Pradesh, India
| | - Pankaj Pathak
- , Roentgen-SAIMS Radiation Oncology Centre, Sri Aurobindo Institute of Medical Sciences, Indore, Madhya Pradesh, India
| | - Prapti Patel
- , Roentgen-SAIMS Radiation Oncology Centre, Sri Aurobindo Institute of Medical Sciences, Indore, Madhya Pradesh, India
| | - Garima Shrivastav
- , Roentgen-SAIMS Radiation Oncology Centre, Sri Aurobindo Institute of Medical Sciences, Indore, Madhya Pradesh, India
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Jabbour JM, Cheng S, Malik BH, Cuenca R, Jo JA, Wright J, Cheng YSL, Maitland KC. Fluorescence lifetime imaging and reflectance confocal microscopy for multiscale imaging of oral precancer. J Biomed Opt 2013; 18:046012. [PMID: 23595826 PMCID: PMC3628018 DOI: 10.1117/1.jbo.18.4.046012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 03/19/2013] [Accepted: 03/22/2013] [Indexed: 05/19/2023]
Abstract
Optical imaging techniques using a variety of contrast mechanisms are under evaluation for early detection of epithelial precancer; however, tradeoffs in field of view (FOV) and resolution may limit their application. Therefore, we present a multiscale multimodal optical imaging system combining macroscopic biochemical imaging of fluorescence lifetime imaging (FLIM) with subcellular morphologic imaging of reflectance confocal microscopy (RCM). The FLIM module images a 16×16 mm² tissue area with 62.5 μm lateral and 320 ps temporal resolution to guide cellular imaging of suspicious regions. Subsequently, coregistered RCM images are acquired at 7 Hz with 400 μm diameter FOV, <1 μm lateral and 3.5 μm axial resolution. FLIM-RCM imaging was performed on a tissue phantom, normal porcine buccal mucosa, and a hamster cheek pouch model of oral carcinogenesis. While FLIM is sensitive to biochemical and macroscopic architectural changes in tissue, RCM provides images of cell nuclear morphology, all key indicators of precancer progression.
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Affiliation(s)
- Joey M. Jabbour
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843
| | - Shuna Cheng
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843
| | - Bilal H. Malik
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843
| | - Rodrigo Cuenca
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843
| | - Javier A. Jo
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843
| | - John Wright
- Texas A&M University Health Science Center—Baylor College of Dentistry, Department of Diagnostic Sciences, 3302 Gaston Avenue, Dallas, Texas 75246
| | - Yi-Shing Lisa Cheng
- Texas A&M University Health Science Center—Baylor College of Dentistry, Department of Diagnostic Sciences, 3302 Gaston Avenue, Dallas, Texas 75246
| | - Kristen C. Maitland
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843
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Akl TJ, King TJ, Long R, McShane MJ, Nance Ericson M, Wilson MA, Coté GL. Performance assessment of an opto-fluidic phantom mimicking porcine liver parenchyma. J Biomed Opt 2012; 17:077008. [PMID: 22894521 PMCID: PMC3394684 DOI: 10.1117/1.jbo.17.7.077008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 06/06/2012] [Accepted: 06/14/2012] [Indexed: 06/01/2023]
Abstract
An implantable, optical oxygenation and perfusion sensor to monitor liver transplants during the two-week period following the transplant procedure is currently being developed. In order to minimize the number of animal experiments required for this research, a phantom that mimics the optical, anatomical, and physiologic flow properties of liver parenchyma is being developed as well. In this work, the suitability of this phantom for liver parenchyma perfusion research was evaluated by direct comparison of phantom perfusion data with data collected from in vivo porcine studies, both using the same prototype perfusion sensor. In vitro perfusion and occlusion experiments were performed on a single-layer and on a three-layer phantom perfused with a dye solution possessing the absorption properties of oxygenated hemoglobin. While both phantoms exhibited response patterns similar to the liver parenchyma, the signal measured from the multilayer phantom was three times higher than the single layer phantom and approximately 21 percent more sensitive to in vitro changes in perfusion. Although the multilayer phantom replicated the in vivo flow patterns more closely, the data suggests that both phantoms can be used in vitro to facilitate sensor design.
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Affiliation(s)
- Tony J. Akl
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843-3120
| | - Travis J. King
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843-3120
| | - Ruiqi Long
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843-3120
| | - Michael J. McShane
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843-3120
| | - M. Nance Ericson
- Oak Ridge National Laboratory, P.O. Box 2008, MS 6006, Oak Ridge, Tennessee 37831-6006
| | - Mark A. Wilson
- University of Pittsburgh, Department of Surgery, 200 Lothrop Street, Pittsburgh, Pennsylvania 15213
- University Dr. C-1w142, Veterans Affairs Healthcare System, Pittsburgh, Pennsylvania 15240
| | - Gerard L. Coté
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, 3120 TAMU, College Station, Texas 77843-3120
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Jaradat A, Al-Akhras MAH, Makhadmeh G, Aljarrah K, Al-omari A, Ababneh Z, Masadeh MM, Al-Khateeb HM, Albiss BA, Alshorman M. Artificial semi-rigid tissue sensitized with natural pigments: Effect of photon radiations. J Pharm Bioallied Sci 2011; 3:266-76. [PMID: 21687357 PMCID: PMC3103923 DOI: 10.4103/0975-7406.80781] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/10/2010] [Accepted: 01/05/2011] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND A new approach for evaluating the optical penetration depth and testing its validity with Monte Carlo simulations and Kubelka-Munk theory is used for artificial semi-rigid tissue sensitized with natural pigments. Photodynamic therapy is a promising cancer treatment in which a photosensitizing drug concentrates in malignant cells and is activated by visible light at certain wavelength. MATERIALS AND METHODS Cheap artificial semi-rigid tissue incorporated with scattering and absorbing materials along with some other composites comparable to normal human tissue has been performed. The optical parameters as measured with different conditions and calculated with various techniques are investigated. RESULTS The probability of interaction of light with tissue is very high when exposed to light in presence of Cichorium pumilum and RBCs followed by photohemolysis or/and photodegradation. The optical penetration depth calculated by linear absorption coefficient ranges from 0.63 to 2.85 mm is found to be comparable to those calculated using Kubelka-Munk theory or Monte Carlo simulation (range from 0.78 to 2.42 mm). The ratio of absorption to the scattering is independent of thickness and decreases with increasing irradiation time. Moreover, the optical parameters as well as their ratios are in very good agreement in the two approaches of calculation. The values of absorption and scattering coefficients are independent of thickness. Furthermore, the average photon ranges in the samples containing no scattering and absorbing materials are about three times greater than those samples containing scattering materials. CONCLUSION Our results suggest that light propagation with optical properties presented in this work could be applicable in diagnostic and therapeutic of the human biological tissue for photodynamic therapy.
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Affiliation(s)
- Adnan Jaradat
- Department of Physics, Bio-Medical Physics Laboratory, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan
| | - M-Ali H. Al-Akhras
- Department of Physics, Bio-Medical Physics Laboratory, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan
| | - G. Makhadmeh
- Department of Physics, Bio-Medical Physics Laboratory, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan
| | - K. Aljarrah
- Department of Physics, Bio-Medical Physics Laboratory, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan
| | - A. Al-omari
- Department of General and Pediatric Surgery, Faculty of Medicine, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan, Jordan
| | - Z. Ababneh
- Department of Physics, Yarmouk University, Faculty of Pharmacy, Jordan
| | - Majed M. Masadeh
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan
| | - H. M. Al-Khateeb
- Department of Physics, Bio-Medical Physics Laboratory, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan
| | - B. A. Albiss
- Department of Physics, Bio-Medical Physics Laboratory, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan
| | - M. Alshorman
- Department of Physics, Bio-Medical Physics Laboratory, Jordan University of Science and Technology (JUST), P.O. Box 3030, Irbid 22110, Jordan
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Maxwell AD, Wang TY, Yuan L, Duryea AP, Xu Z, Cain CA. A tissue phantom for visualization and measurement of ultrasound-induced cavitation damage. Ultrasound Med Biol 2010; 36:2132-43. [PMID: 21030142 PMCID: PMC2997329 DOI: 10.1016/j.ultrasmedbio.2010.08.023] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 08/18/2010] [Accepted: 08/30/2010] [Indexed: 05/03/2023]
Abstract
Many ultrasound studies involve the use of tissue-mimicking materials to research phenomena in vitro and predict in vivo bioeffects. We have developed a tissue phantom to study cavitation-induced damage to tissue. The phantom consists of red blood cells suspended in an agarose hydrogel. The acoustic and mechanical properties of the gel phantom were found to be similar to soft tissue properties. The phantom's response to cavitation was evaluated using histotripsy. Histotripsy causes breakdown of tissue structures by the generation of controlled cavitation using short, focused, high-intensity ultrasound pulses. Histotripsy lesions were generated in the phantom and kidney tissue using a spherically focused 1-MHz transducer generating 15 cycle pulses, at a pulse repetition frequency of 100 Hz with a peak negative pressure of 14 MPa. Damage appeared clearly as increased optical transparency of the phantom due to rupture of individual red blood cells. The morphology of lesions generated in the phantom was very similar to that generated in kidney tissue at both macroscopic and cellular levels. Additionally, lesions in the phantom could be visualized as hypoechoic regions on a B-mode ultrasound image, similar to histotripsy lesions in tissue. High-speed imaging of the optically transparent phantom was used to show that damage coincides with the presence of cavitation. These results indicate that the phantom can accurately mimic the response of soft tissue to cavitation and provide a useful tool for studying damage induced by acoustic cavitation.
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Affiliation(s)
- Adam D Maxwell
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2099, USA.
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Kumar K, Andrews M, Jayashankar V, Mishra A, Suresh S. Improvement in diagnosis of breast tumour using ultrasound elastography and echography: A phantom based analysis. Biomed Imaging Interv J 2009; 5:e30. [PMID: 21610995 DOI: 10.2349/biij.5.4.e30] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 09/18/2009] [Indexed: 11/23/2022] Open
Abstract
Due to the isoechoic nature of lesions and their poor contrast with neighbouring tissue, a lesion may remain undetected in ultrasound B mode imaging for cancerous tissue. Imaging of the elastic properties of tissue provides new information which is collateral to tissue pathology. This study provides quantitative analysis of improvements in tumour diagnosis when the ultrasound B mode imaging is combined with elastography. Quantification was based on the textural parameters measured from the ultrasound B mode image and strain measured from the elastogram. The ability of a parameter to discriminate between diseased cases and normal cases was evaluated using receiver operating characteristic (ROC) analysis. Polyacrylamide gel based tissue mimicking phantoms with embedded inclusions of varying stiffness were used for the analysis.
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Pramanik M, Wang LV. Thermoacoustic and photoacoustic sensing of temperature. J Biomed Opt 2009; 14:054024. [PMID: 19895126 PMCID: PMC2774978 DOI: 10.1117/1.3247155] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 07/07/2009] [Accepted: 08/06/2009] [Indexed: 05/18/2023]
Abstract
We present a novel temperature-sensing technique using thermoacoustic and photoacoustic measurements. This noninvasive method has been demonstrated using a tissue phantom to have high temporal resolution and temperature sensitivity. Because both photoacoustic and thermoacoustic signal amplitudes depend on the temperature of the source object, the signal amplitudes can be used to monitor the temperature. A temperature sensitivity of 0.15 degrees C was obtained at a temporal resolution as short as 2 s, taking the average of 20 signals. The deep-tissue imaging capability of this technique can potentially lead us to in vivo temperature monitoring in thermal or cryogenic applications.
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Affiliation(s)
- Manojit Pramanik
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, Campus Box 1097, One Brookings Drive, St. Louis, Missouri 63130, USA
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