Publications — Featuring United Biologics Models

Published Articles

Third-Generation Cardiovascular Phantom: The Next Generation of Preclinical Research in Diagnostic Imaging

Investigative Radiology

Michael C. McDermott, BSc, Thomas Sartoretti, BSc, Casper Mihl, MD, PhD, Hubertus Pietsch, VMD, PhD,  Hatem Alkadhi, MD, PhD, and Joachim E. Wildberger, MD, PhD

Abstract Different types of preclinical research tools used in the field of diagnostic imaging such as dynamic flow circulation phantoms have built the foundation for optimization and advancement of clinical procedures including newimaging techniques.
The objectivewas to introduce a third-generation phantom, building on the limitations of earlier versions and unlocking new opportunities for preclinical investigation.

Read more

Watershed phenomena during extracorporeal life support and their clinical impact: a systematic in vitro investigation

ESC Heart Failure

Johannes Gehron, Maximilian Schuster, Florian Rindler, Markus Bongert, Andreas Böning, Gabriele Krombach, Martin Fiebich, Philippe Grieshaber, EMPACS (Exploration of the mixing phenomena during interaction of internal and external circulations) study group

Abstract Extracorporeal life support (ECLS) during acute cardiac failure restores haemodynamic stability and provides life‐saving cardiopulmonary support. Unfortunately, all common cannulation strategies and remaining pulmonary blood flow increase left‐ventricular afterload and may favour pulmonary congestion.

Read more

Neuroangiography simulation using a silicone model in the angiography suite improves trainee skills

Journal of NeuroInterventional Surgery

Amrendra S Miranpuri, Christopher M Nickele, Erinc Akture, Kevin Royalty, David B Niemann

Purpose Simulation techniques in neurosurgical training are becoming more important. The purpose of this study was to determine whether silicone vascular models used in the angiography suite can render improvement in trainee performance and safety in neuroendovascular procedures.

Read more

E-106 Feasibility of automation of staged balloon guide catheter (BGC) aspiration during stroke thrombectomy using a customizable Ipad app and a bluetooth-enabled smart pump: an in-vitro study

Journal of NeuroInterventional Surgery

B Jagadeesan, V Janardhan, V Janardhan

Purpose Balloon Guide Catheter (BGC) aspiration is becoming increasingly recognized as an important adjunctive technique to stroke thrombectomy for improving first pass recanalization as well as clinical outcomes. Currently, BGC aspiration requires two operators, one for thrombectomy and second for staged BGC aspiration using a manual syringe. Automating BGC aspiration using a customizable iPad app and a smart pump would enable stroke thrombectomy to be performed with a single operator, and potentially help alleviate some of the manpower challenges for 24/7 coverage for stroke thrombectomies globally.

Read more

Dynamic heart phantom with functional mitral and aortic valves

Journal of NeuroInterventional Surgery

Amrendra S Miranpuri, Christopher M Nickele, Erinc Akture, Kevin Royalty, David B Niemann

Abstract Cardiac valvular stenosis, prolapse and regurgitation are increasingly common conditions, particularly in an elderly population with limited potential for on-pump cardiac surgery. NeoChord©, MitraClip© and numerous stent-based transcatheter aortic valve implantation (TAVI) devices provide an alternative to intrusive cardiac operations; performed while the heart is beating, these procedures require surgeons and cardiologists to learn new image-guidance based techniques.

Read more

E-108 Aladin study: automated large artery occlusion detection in stroke imaging study – a multicenter analysis

Journal of NeuroInterventional Surgery

C Barreira1, M Bouslama1, J Lim2, A Al-Bayati1, Y Saleem1, T Devlin3, D Haussen1, M Froehler2, J Grossberg4, B Baxter3, M Frankel1, R Nogueira1

Introduction Large Vessel Occlusion (LVO) for Acute Ischemic Stroke (AIS) remains a public health issue as there is significant morbidity and mortality when left untreated. Timely recognition, therefore, is of utmost significance, as there are validated therapeutic options involving cerebrovascular reperfusion. Best patient care relies on tailored and expeditious clinical identification, using multimodal neuroimaging and facilitating referrals to comprehensive centers. Artificial Intelligence (AI)-guided technologies applied to medical fields are being used increasingly and may improve LVO recognition. We present an AI-based algorithm for LVO detection.

Read more

Physical Simulators and Replicators in Endovascular Neurosurgery Training

Comprehensive Healthcare Simulation: Neurosurgery

Chander Sadasivan, Baruch B. Lieber, Henry H. Woo

Abstract The increased adoption of endovascular neurosurgery procedures to treat cerebrovascular pathologies has led to the commercialization of a wide array of medical devices which, in turn, necessitates a more sophisticated training environment for physicians and fellows than the traditional “see one, do one, teach one” concept. Improvements in simulation technology and a changing healthcare culture are facilitating a wider assimilation of benchtop simulation models in lieu of cadaver or animal models in physician training as well as treatment planning.

Read more

Intact and Isolated Human Cadaveric Coronary Artery Perfusion Models to Facilitate Research and Education Regarding Coronary Anatomy and Pathology

Journal of Invasive Cardiology

John L. Petersen, MD, MHS1; Dmitry B. Levin, BS2; Vivian W. Hou, MS2; Carol V. Hagen, CDT1; Grant Anderson, BS3; Joanie Block, BS, MA4; Mark Reisman, MD2

Abstract Cadaveric tissue-perfusion models are well established in the fields of structural heart and peripheral vascular disease; however, less consideration has been given toward coronary artery disease despite comparable prevalence and morbidity. Two tissue-perfusion models were developed to address this need.

Read more

Development of an Experimental and Digital Cardiovascular Arterial Model for Transient Hemodynamic and Postural Change Studies: “A Preliminary Framework Analysis”

Cardiovascular Engineering and Technology

Rodward L. Hewlin Jr. & John P. Kizito

Abstract The ultimate goal of the present work is to aid in the development of tools to assist in the treatment of cardiovascular disease. Gaining an understanding of hemodynamic parameters for medical implants allow clinicians to have some patient-specific proposals for intervention planning.

Read more

Optimizating Clot Retrieval in Acute Stroke - The Push and Fluff Technique for Closed-Cell Stentrievers”


Diogo C. Haussen, MD; Leticia C. Rebello, MD; Raul G. Nogueira, MD

Background We aimed to investigate the safety and efficacy of the Push and Fluff technique (PFT) as compared with the standard unsheathing technique for closed-cell stent retrievers in acute ischemic stroke.

Read more

In vitro investigation of contrast flow jet timing in patient-specific intracranial aneurysms”

Quantitative Imaging in Medicine and Surgery

Liang-der Jou, Virendra R. Desai, Garvin W. Britz

Background The direction and magnitude of intra-aneurysmal flow jet are significant risk factors of subarachnoid hemorrhage, and the change of flow jet during an endovascular procedure has been used for prediction of aneurysm occlusion or whether an additional flow diverter (FD) is warranted. However, evaluation of flow jets is often unreliable due to a large variation of flow jet on the digital subtraction angiograms, and this flow pattern variation may result in incorrect clinical diagnosis Therefore, factors contributing to the variation in flow jet are examined at an in vitro setting, and the findings can help us
to understand the nature of flow jet and devise a better plan to quantify the aneurysmal hemodynamics accurately.

Read more

Cannula position and Bernoulli effect contribute to leg malperfusion during extracorporeal life support with femoral arterial cannulation—an in silico simulation study”

Interactive CardioVascular and Thoracic Surgery

Markus Bongerta, Johannes Gehronb,Marius Gellera, Andreas Boningb and Philippe Grieshaberb,*

AbstractLimb ischaemia during extracorporeal life support (ECLS) using femoral artery cannulation is frequently observed even in patients with regular vessel diameters and without peripheral arterial occlusive disease. We investigated underlying pathomechanisms using a virtual fluid-mechanical simulation of the human circulation.

Read more

Development and Validation of a Life-Sized Mock Circulatory Loop of the Human Circulation for Fluid-Mechanical Studies”

ASAIO - American Society for Artificial Internal Organs

Johannes Gehron 1, Julian Zirbes 1, Markus Bongert 2, Stefan Schäfer 3, Martin Fiebich 4, Gabriele Krombach 3, Andreas Böning 1, Philippe Grieshaber 1, EMPACS (Exploration of the mixing phenomena during interaction of internal and external circulations) study group

Background Mock circulatory loops (MCLs) are usually developed for assessment of ventricular assist devices and consist of abstracted anatomical structures represented by connecting tubing pipes and controllable actuators which could mimic oscillating flow processes. However, with increasing use of short-term peripheral mechanical support (extracorporeal life support [ECLS]) and the upcoming evidence of even counteracting flow processes between the failing native circulation and ECLS, MCLs incorporating the peripheral vascular system and preserved anatomical structures are becoming more important for systematic assessment of these processes.

Read more

In silico study of the dynamic interaction between extracorporeal circulation and native circulation”

Current Directions in Biomedical Engineering

Markus Bongert*, Johannes Gehron, Marius Geller, Andreas Böning, and Philippe Grieshaber

Abstract An in silico investigation of modelled Extracorporeal Life Support (ECLS) via a femoral arterial cannula revealed the existence of both a defined separation zone between the opposing flows (ECLS, native flow) and different ranges dependent on flow distribution. The interaction between pulsating native circulation and constant ECLS flow is dynamic. A transient simulation model was developed to investigate the dynamic influence on this fluid mechanical interaction.

Read more

Theses and Dissertations

Development of In Vitro Tissue Engineered Blood Vessel Mimics in Complex Geometries for Coronary Stent Testing

Robert Dalton Chavez
California Polytechnic State University, San Luis Obispo

Abstract Coronary heart disease is the leading cause of death in the United States and occurs when plaque occludes coronary arteries. Coronary stents, which may be used to treat coronary occlusions, are small metal tubes that are implanted in coronary arteries to restore blood flow. After stent implantation, endothelial cells grow over the stent so that blood contacts the endothelial cells instead of the stent surface; this event is known as reendothelialization. Re-endothelialization prevents blood from clotting on the stent surface and is a good predictor of stent success. Blood vessel mimics (BVMs) are in vitro tissue engineered models of human blood vessels that may be used to preclinically test coronary stents for re-endothelialization.

Read more

Sviluppo Di Un Metodo Per La Realizzazione Di Modelli Vascolari Paziente-Specifici Per Il Training In Operazioni Transcatetere

Francesca Perico
Facoltà di Ingegneria Industriale e dell’Informazione

Abstract Le patologie cardiovascolari sono tra le principali cause di morte nella maggior parte dei paesi occidentali; tra queste si distinguono le valvulopatie, anomalie anatomiche o funzionali che interessano le valvole cardiache. Secondo la cardiochirurgia tradizionale, le valvulopatie sono trattate tramite la così detta chirurgia a cuore aperto che prevede spesso la rimozione della valvola patologica e l’inserimento di una valvola artificiale che svolga le medesime funzioni.

Read more

Windkessel Modeling of the Human Arterial System

Nuria Peña Pérez

Abstract Cardiovascular diseases are a major concern of our society. Millions of patients all around the world are affected by disorders such as arrhythmias or atherosclerosis. Moreover, finding new diagnostic techniques and treatments is of increased difficulty due to the complexity of cardiovascular medicine. In this context, the upcoming generations of experts must be well prepared for overcoming such a challenge. This project aims to develop an educational tool that will allow students to improve their understanding on cardiovascular fluid mechanics and physiology and will allow them to gain practical experience before dealing with real patients.

Read more

Papers Referencing United Biologics Website

Dynamic Patient-Specific Three-Dimensional Simulation of Mitral Repair: Can We Practice Mitral Repair Preoperatively?

Cardiovascular Engineering and Technology

Olivia K. Ginty, MSc, John M. Moore, MSc, Yuanwei Xu, Wenyao Xia, MSc, Satoru Fujii, MD, Daniel Bainbridge, MD, Terry M. Peters, PhD, Bob B. Kiaii, MD, Michael W. A. Chu, MD

Abstract Planned mitral repair strategies are generally established from preoperative echocardiography; however, specific details of the repair are often determined intraoperatively. We propose that three-dimensional printed, patient-specific, dynamic mitral valve models may help surgeons plan and trial all the details of a specific patient's mitral repair preoperatively.

Read more

Studies Featured in Conferences

Customizable Uniform and Cyclical Aspiration Thrombectomy Using a Digital Smart Pump: An In-Vitro Feasibility Study

Society of Vascular and Interventional Neurology

Bharathi D Jagadeesan, MD, Alex Abou-Chebi, MD, FSVIN, Vikram Janardhan, PhD, Vallabh Janardhan, MD, FSVIN

Introduction Aspiration is an important part of stroke thrombectomy (1). Pre-clinical studies have also suggested that uniform aspiration may need to be customized for varying vessel diameters and that cyclical (varying suction intensity) aspiration may be more effective (2).

Read more

Design for Mass Adaptation of the Neurointerventional Training Model HANNES with Patient-Specific Aneurysm Models

Kyselyova, Anna (2); Fiehler, Jens (2); Krause, Dieter (1)
Design Society: International Conference on Engineering Design

Spallek, Johanna (1); Kuhl, Juliane (1); Wortmann, Nadine (1); Buhk, Jan-Hendrik (2); Frölich, Andreas Maximilian (2); Nawka, Marie Teresa (2);

Abstract A neurointerventional training model called HANNES (Hamburg ANatomical NEurointerventional Simulator) has been developed to replace animal models in catheter-based aneurysm treatment training. A methodical approach to design for mass adaptation is applied so that patient-specific aneurysm models can be designed recurrently based on real patient data to be integrated into the training system.

Read more