1
|
Kubicki C, Raich E, Selinsky P, Ponnaluri S, Weiss WJ, Manning KB. Fluid Dynamic Study of the Penn State Pediatric Total Artificial Heart. J Biomech Eng 2024; 146:101007. [PMID: 38652582 PMCID: PMC11110827 DOI: 10.1115/1.4065377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/25/2024]
Abstract
Penn State University is developing a pediatric total artificial heart (TAH) as a bridge-to-transplant device that supports infants and small children with single ventricle anomalies or biventricular heart failure to address high waitlist mortality rates for pediatric patients with severe congenital heart disease (CHD). Two issues with mechanical circulatory support devices are thrombus formation and thromboembolic events. This in vitro study characterizes flow within Penn State's pediatric total artificial heart under physiological operating conditions. Particle image velocimetry (PIV) is used to quantify flow within the pump and to calculate wall shear rates (WSRs) along the internal pump surface to identify potential thrombogenic regions. Results show that the diastolic inflow jets produce sufficient wall shear rates to reduce thrombus deposition potential along the inlet side of the left and right pumps. The inlet jet transitions to rotational flow, which promotes wall washing along the apex of the pumps, prevents flow stasis, and aligns flow with the outlet valve prior to systolic ejection. However, inconsistent high wall shear rates near the pump apex cause increased thrombogenic potential. Strong systolic outflow jets produce high wall shear rates near the outlet valve to reduce thrombus deposition risk. The right pump, which has a modified outlet port angle to improve anatomical fit, produces lower wall shear rates and higher thrombus susceptibility potential (TSP) compared to the left pump. In summary, this study provides a fluid dynamic understanding of a new pediatric total artificial heart and indicates thrombus susceptibility is primarily confined to the apex, consistent with similar pulsatile heart pumps.
Collapse
Affiliation(s)
- Cody Kubicki
- Department of Biomedical Engineering, The Pennsylvania State University, 122 CBEB Shortlidge Road, University Park, PA 16802
| | - Emma Raich
- Department of Biomedical Engineering, The Pennsylvania State University, 122 CBEB Shortlidge Road, University Park, PA 16802
| | - Peter Selinsky
- Department of Biomedical Engineering, The Pennsylvania State University, 122 CBEB Shortlidge Road, University Park, PA 16802
| | - Sailahari Ponnaluri
- Department of Biomedical Engineering, The Pennsylvania State University, 122 CBEB Shortlidge Road, University Park, PA 16802
| | - William J. Weiss
- Department of Surgery, Penn State College of Medicine, 700 HMC Crescent Road, Hershey, PA 17033
| | - Keefe B. Manning
- Department of Biomedical Engineering, The Pennsylvania State University, 122 CBEB Shortlidge Road, University Park, PA 16802
| |
Collapse
|
2
|
Ponnaluri SV, Houtz BL, Raich EC, Good BC, Deutsch S, Weiss WJ, Manning KB. Effect of Hematocrit and Elevated Beat Rate on the 12cc Penn State Pediatric Ventricular Assist Device. ASAIO J 2023; 69:1065-1073. [PMID: 37549654 PMCID: PMC10840605 DOI: 10.1097/mat.0000000000002028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023] Open
Abstract
Congenital heart disease affects approximately 40,000 infants annually in the United States with 25% requiring invasive treatment. Due to limited number of donor hearts and treatment options available for children, pediatric ventricular assist devices (PVADs) are used as a bridge to transplant. The 12cc pneumatic Penn State PVAD is optimized to prevent platelet adhesion and thrombus formation at patient nominal conditions; however, children demonstrate variable blood hematocrit and elevated heart rates. Therefore, with pediatric patients exhibiting greater variability, particle image velocimetry is used to evaluate the PVAD with three non-Newtonian hematocrit blood analogs (20%, 40%, and 60%) and at two beat rates (75 and 120 bpm) to understand the device's performance. The flow fields demonstrate a strong inlet jet that transitions to a solid body rotation during diastole. During systole, the rotation dissipates and reorganizes into an outlet jet. This flow field is consistent across all hematocrits and beat rates but at a higher velocity magnitude during 120 bpm. There are also minor differences in flow field timing and surface washing due to hematocrit. Therefore, despite patient differences in hematocrit or required pumping output, thorough surface washing can be achieved in the PVAD by altering operating conditions, thus reducing platelet adhesion potential.
Collapse
Affiliation(s)
- Sailahari V Ponnaluri
- From the Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Brady L Houtz
- From the Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Emma C Raich
- From the Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Bryan C Good
- From the Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Steven Deutsch
- From the Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - William J Weiss
- Department of Surgery, Penn State Hershey Medical Center, Hershey, Pennsylvania
| | - Keefe B Manning
- From the Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania
- Department of Surgery, Penn State Hershey Medical Center, Hershey, Pennsylvania
| |
Collapse
|
3
|
Lemos BLHD, Bortolin VAA, de Lima Amaral R, Mazzetto M, Cestari IA, Meneghini JR. Effect of the bileaflet inlet valve angle on the flow of a pediatric ventricular assist device: experimental analysis. Artif Organs 2022; 46:1833-1846. [PMID: 35524699 DOI: 10.1111/aor.14282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 03/29/2022] [Accepted: 04/29/2022] [Indexed: 12/01/2022]
Abstract
BACKGROUND Mechanical heart valves (MHV) and its fluid dynamics inside a pulsatile pediatric ventricular assist device (PVAD) can be associated with blood degradation. In this paper, flow structures are analyzed and compared by an experimental investigation on the effect of bileaflet MHV positioned at varying angles in the inlet port orifice of a PVAD. METHODS Time-resolved particle image velocimetry (TR-PIV) was applied to characterize the internal flow of the device. St Jude Medical bileaftlet valves were used on the inlet orifice and positioned at 0°, 15°, 30°, 45°, 60°, and 90° in relation to the centerline of the device. Three planes with bidimensional velocity magnitude fields were considered in the analysis with visualization of diastolic jets, device wall washing patterns and flow circulation during emptying or systole of the pump. Also, the washing vortex area, and vertical velocity probabilities of regurgitant flows in the inlet valve were evaluated. RESULTS The results show that a variation in the angle of the MHV at the inlet port produced distinct velocities, fluid structures, and regurgitant flow probabilities within the device. MHV positioned at an angle of 0° generated the strongest inlet jet, larger vortex area during filling, more prominent outgoing flow, and less regurgitation compared to the angles studied. The presence of unfavorable fluid structures, such as small vortices, and/or sudden flow structure interruption, and/or regurgitation, were identified at 45° and 90° angles. CONCLUSIONS The 0° inlet angle had better outcomes than other angles due to its consistency in the multiple parameters analyzed.
Collapse
Affiliation(s)
| | | | - Rodrigo de Lima Amaral
- Escola Politécnica da Universidade de São Paulo (EP USP), Av. Prof. Mello Moraes 2231, São Paulo, Brazil
| | - Marcelo Mazzetto
- Bioengineering Laboratory, Heart Institute, Hospital das Clínicas, HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Enéas Carvalho de Aguiar 44, São Paulo, Brazil
| | - Idágene Aparecida Cestari
- Bioengineering Laboratory, Heart Institute, Hospital das Clínicas, HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Enéas Carvalho de Aguiar 44, São Paulo, Brazil
| | - Julio Romano Meneghini
- Escola Politécnica da Universidade de São Paulo (EP USP), Av. Prof. Mello Moraes 2231, São Paulo, Brazil
| |
Collapse
|
4
|
Palazzolo T, Hirschhorn M, Garven E, Day S, Stevens RM, Rossano J, Tchantchaleishvili V, Throckmorton AL. Technology Landscape of Pediatric Mechanical Circulatory Support Devices- A Systematic Review 2010-2021. Artif Organs 2022; 46:1475-1490. [PMID: 35357020 PMCID: PMC9256769 DOI: 10.1111/aor.14242] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 02/17/2022] [Accepted: 03/15/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mechanical circulatory support (MCS) devices, such as ventricular assist devices (VADs) and total artificial hearts (TAHs), have become a vital therapeutic option in the treatment of end-stage heart failure for adult patients. Such therapeutic options continue to be limited for pediatric patients. Clinicians initially adapted or scaled existing adult devices for pediatric patients; however, these adult devices are not designed to support the anatomical structure and varying flow capacities required for this population and are generally operated "off-design", which risks complications such as hemolysis and thrombosis. Devices designed specifically for the pediatric population that seek to address these shortcomings are now emerging and gaining FDA approval. METHODS To analyze the competitive landscape of pediatric MCS devices, we conducted a systematic literature review. Approximately 27 devices were studied in detail: 8 were established or previously approved designs, and 19 were under development (11 VADs, 5 Fontan assist devices, and 3 TAHs). RESULTS Despite significant progress, there is still no pediatric pump technology that satisfies the unique and distinct design constraints and requirements to support pediatric patients, including the wide range of patient sizes, increased cardiovascular demand with growth, and anatomic and physiologic heterogeneity of congenital heart disease. CONCLUSIONS Forward-thinking design solutions are required to overcome these challenges and to ensure the translation of new therapeutic MCS devices for pediatric patients.
Collapse
Affiliation(s)
- Thomas Palazzolo
- BioCirc Research Laboratory, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Matthew Hirschhorn
- BioCirc Research Laboratory, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Ellen Garven
- BioCirc Research Laboratory, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Steven Day
- Department of Biomedical Engineering, Kate Gleason College of Engineering, Rochester Institute of Technology, Rochester, NY, USA
| | - Randy M Stevens
- College of Medicine, St. Christopher's Hospital for Children, Drexel University, Philadelphia, PA, USA
| | - Joseph Rossano
- Division of Pediatric Cardiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Vakhtang Tchantchaleishvili
- Division of Cardiac Surgery, Department of Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Amy L Throckmorton
- BioCirc Research Laboratory, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA
| |
Collapse
|
5
|
Caimi A, Sturla F, Good B, Vidotto M, De Ponti R, Piatti F, Manning KB, Redaelli A. Toward the Virtual Benchmarking of Pneumatic Ventricular Assist Devices: Application of a Novel Fluid-Structure Interaction-Based Strategy to the Penn State 12 cc Device. J Biomech Eng 2017; 139:2630936. [PMID: 28586917 DOI: 10.1115/1.4036936] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Indexed: 11/08/2022]
Abstract
The pediatric use of pneumatic ventricular assist devices (VADs) as a bridge to heart transplant still suffers for short-term major complications such as bleeding and thromboembolism. Although numerical techniques are increasingly exploited to support the process of device optimization, an effective virtual benchmark is still lacking. Focusing on the 12 cc Penn State pneumatic VAD, we developed a novel fluid-structure interaction (FSI) model able to capture the device functioning, reproducing the mechanical interplay between the diaphragm, the blood chamber, and the pneumatic actuation. The FSI model included the diaphragm mechanical response from uniaxial tensile tests, realistic VAD pressure operative conditions from a dedicated mock loop system, and the behavior of VAD valves. Our FSI-based benchmark effectively captured the complexity of the diaphragm dynamics. During diastole, the initial slow diaphragm retraction in the air chamber was followed by a more rapid phase; asymmetries were noticed in the diaphragm configuration during its systolic inflation in the blood chamber. The FSI model also captured the major features of the device fluid dynamics. In particular, during diastole, a rotational wall washing pattern is promoted by the penetrating inlet jet with a low-velocity region located in the center of the device. Our numerical analysis of the 12 cc Penn State VAD points out the potential of the proposed FSI approach well resembling previous experimental evidences; if further tested and validated, it could be exploited as a virtual benchmark to deepen VAD-related complications and to support the ongoing optimization of pediatric devices.
Collapse
Affiliation(s)
- Alessandro Caimi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano 20133, Italy e-mail:
| | - Francesco Sturla
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano 20133, Italy e-mail:
| | - Bryan Good
- Department of Biomedical Engineering, The Pennsylvania State University, State College, PA 16802 e-mail:
| | - Marco Vidotto
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano 20133, Italy e-mail:
| | - Rachele De Ponti
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano 20133, Italy e-mail:
| | - Filippo Piatti
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano 20133, Italy e-mail:
| | - Keefe B Manning
- Mem. ASME Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802 e-mail:
| | - Alberto Redaelli
- Mem. ASME Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano 20133, Italy e-mail:
| |
Collapse
|
6
|
Arjunon S, Ardana PH, Saikrishnan N, Madhani S, Foster B, Glezer A, Yoganathan AP. Design of a pulsatile flow facility to evaluate thrombogenic potential of implantable cardiac devices. J Biomech Eng 2015; 137:045001. [PMID: 25587891 DOI: 10.1115/1.4029579] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Indexed: 11/08/2022]
Abstract
Due to expensive nature of clinical trials, implantable cardiac devices should first be extensively characterized in vitro. Prosthetic heart valves (PHVs), an important class of these devices, have been shown to be associated with thromboembolic complications. Although various in vitro systems have been designed to quantify blood-cell damage and platelet activation caused by nonphysiological hemodynamic shear stresses in these PHVs, very few systems attempt to characterize both blood damage and fluid dynamics aspects of PHVs in the same test system. Various numerical modeling methodologies are also evolving to simulate the structural mechanics, fluid mechanics, and blood damage aspects of these devices. This article presents a completely hemocompatible small-volume test-platform that can be used for thrombogenicity studies and experimental fluid mechanics characterization. Using a programmable piston pump to drive freshly drawn human blood inside a cylindrical column, the presented system can simulate various physiological and pathophysiological conditions in testing PHVs. The system includes a modular device-mounting chamber, and in this presented case, a 23 mm St. Jude Medical (SJM) Regents® mechanical heart valve (MHV) in aortic position was used as the test device. The system was validated for its capability to quantify blood damage by measuring blood damage induced by the tester itself (using freshly drawn whole human blood). Blood damage levels were ascertained through clinically relevant assays on human blood while fluid dynamics were characterized using time-resolved particle image velocimetry (PIV) using a blood-mimicking fluid. Blood damage induced by the tester itself, assessed through Thrombin-anti-Thrombin (TAT), Prothrombin factor 1.2 (PF1.2), and hemolysis (Drabkins assay), was within clinically accepted levels. The hydrodynamic performance of the tester showed consistent, repeatable physiological pressure and flow conditions. In addition, the system contains proximity sensors to accurately capture leaflet motion during the entire cardiac cycle. The PIV results showed skewing of the leakage jet, caused by the asymmetric closing of the two leaflets. All these results are critical to characterizing the blood damage and fluid dynamics characteristics of the SJM Regents® MHV, proving the utility of this tester as a precise system for assessing the hemodynamics and thrombogenicity for various PHVs.
Collapse
|
7
|
A novel pediatric biventricular assist device: in vitro test results. ASAIO J 2014; 60:329-34. [PMID: 24618752 DOI: 10.1097/mat.0000000000000060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Most ventricular assist devices (VADs) currently used in infants are extracorporeal. These VADs require long-term anticoagulation therapy and extensive surgery, and two devices are needed for biventricular support. We designed a biventricular assist device based on shape memory alloy that reproduces the hemodynamic effects of cardiomyoplasty, supporting the heart with a compressing movement, and evaluated its performance in a dedicated mockup system. Nitinol fibers are the device's key component. Ejection fraction (EF), cardiac output (CO), and generated systolic pressure were measured on a test bench. Our test bench settings were a preload range of 0-15 mm Hg, an afterload range of 0-160 mm Hg, and a heart rate (HR) of 20, 30, 40, and 60 beats/min. A power supply of 15 volts and 3.5 amperes was necessary. The EF range went from 34.4% to 1.2% as the afterload and HR increased, along with a CO from 180 to 6 ml/min. The device generated a maximal systolic pressure of 25 mm Hg. Cardiac compression for biventricular assistance in child-sized heart using shape memory alloy is technically feasible. Further testing remains necessary to assess this VAD's in vivo performance range and its reliability.
Collapse
|