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Dissertation
Next-gen Dragon Heart: a new blood pumping solution for pediatric patients with heart failure
Doctor of Philosophy (Ph.D.), Drexel University
Jun 2026
DOI:
https://doi.org/10.17918/00011517
Abstract
Pediatric heart failure is a life-threatening condition that affects thousands of children annually and is commonly associated with congenital heart defects, cardiomyopathies, and other severe cardiac diseases. Worldwide, pediatric heart failure impacts tens of thousands of children and historically carries a mortality rate that exceeds 50%. For children with end-stage heart failure, heart transplantation remains the gold standard treatment; however, limited donor organ availability and challenges with donor-recipient size matching, typically necessitate the use of mechanical circulatory support (MCS) devices, or blood pumps, as a bridge-to-transplantation. Pediatric-specific MCS options remain extremely limited, particularly, for infants. Currently, no total artificial heart (TAH) is approved for children younger than 11 years of age, creating a significant unmet need for pediatric-specific MCS technologies. To address this unmet clinical need, we are developing the Drexel Dragon Heart (DH), a novel double-pump, continuous-flow, magnetically levitated TAH for pediatric patients. The device uniquely integrates a centrifugal and an axial blood pump within a single compact housing to provide systemic and pulmonary circulatory support, while maintaining separate fluid domains; this design is the first of its kind. This novel configuration allows for device usage as a TAH for partial or full cardiovascular support, or as a left-sided or right-sided blood pump based on patient support requirements. Leveraging prior research in the iterative development of this device (DH1-DH6), this dissertation work focused on the translational advancement of the centrifugal blood pump, which assists the systemic circulation and represents the largest component of the device. An industry-standard, iterative development roadmap, incorporating design optimization, computational modeling, prototype manufacturing, hydraulic testing, hemolytic evaluation, and acute animal studies, was established and executed to advance the design, model, build and test the next-generation centrifugal pump iterations, DH7 and DH8. The DH7 pump was advanced by implementing the Taguchi Design Optimization method to achieve size requirements and target performance requirements of 1-5 L/min of flow and 60-140 mmHg pressure rise. Computational and experimental evaluations demonstrated that the DH7 consistently achieved the desired hydraulic performance. Design areas of concern included fluid stress analyses that predicted elevated stress concentrations within the outlet volute cutwater region, guiding subsequent design improvements. Hemolytic testing of the magnetically levitated DH7 demonstrated a substantial reduction in blood damage compared with the previous DH6 design, with normalized index of hemolysis values ranging from 0.002-0.036 mg/dL, which was encouraging. Additional hydraulic blood studies confirmed successful tandem operation of the centrifugal and axial pumps without interference. The complete Dragon Heart magnetically levitated prototype (i.e. DH7 centrifugal pump + existing axial LEV-VAD pump) was further evaluated in three acute ovine studies, during which all subjects survived the full six-hour support duration and demonstrated strong hemodynamics and low thrombotic-hemolytic levels. The DH7 centrifugal pump maintained pressures within the target range while providing effective circulatory support in these animal experiments. Building upon these findings, the DH8 was developed to further reduce overall device size and fluid stresses. Development of the DH8 impeller was also facilitated through the Taguchi method. We optimized the outlet volute region of the pump to lower fluid stress levels, thereby mitigating the potential for blood cell trauma at the outlet of the centrifugal pump. The DH7 successfully produced pressures and flows within our target range and minimized the blood damage by 99% as compared to the DH6. In addition, the DH8 design resulted in a 40% size reduction relative to the DH7 and a 55% size reduction relative to the previous iteration, the DH6, all while maintaining the required pressures and flows to sustain pediatric patients. Collectively, this impactful research demonstrates excellent progress toward the translational development of a pediatric TAH. The research findings, device advancement, and success milestones significantly contribute to the body of literature of pediatric blood pump device development and further the long-term goal of establishing a new rotary TAH for the underserved population of children experiencing heart failure, thus addressing a compelling unmet clinical need.
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Details
- Title
- Next-gen Dragon Heart
- Creators
- Giselle C. Matlis
- Contributors
- Amy Throckmorton (Advisor)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University
- Number of pages
- xiv, 203 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- School of Biomedical Engineering, Science, and Health Systems (1997-2026); Drexel University
- Other Identifier
- 991022201056604721