# Pediatric Implantable Low-Shear Pulsatile Blood Pump with Physiologic Sensing and Control

> **NIH NIH R44** · WINDMILL CARDIOVASCULAR SYSTEMS, INC. · 2020 · $747,718

## Abstract

Project Summary / Abstract
The goal of this project is to develop high-level physiological control, improve low-level dynamic piston control,
and develop hemodynamic sensing capabilities for the pediatric TORVADTM, a unique ventricular assist system
that delivers low-shear, synchronous, pulsatile flow, using controlled piston motion within a torus-shaped
pumping chamber. The pediatric TORVAD is intended for patients with a body surface area from 0.6 to 1.5 m2,
but the design can be scaled to adapt to a wide variety of patient sizes and needs. Low shear in the pumped
blood is managed by the relatively low speed of the pistons which are supported by hydrodynamic bearings
that maintain a fixed piston-torus gap. The primary operating mode delivers a 15 mL counterpulse ejection, but
the pump can also operate asynchronously to deliver full cardiac support up to 4 L/min. The system
synchronizes with the heart to preserve aortic valve flow and maintains autoregulation of cardiac output by the
Frank-Starling mechanism. The design of the TORVAD also enables determination of differential pump
pressure, without additional sensors. This inherent sensing capability can be used to inform patient
medications and optimal pump support. These device advantages have been confirmed in benchtop studies
and acute and chronic animal experiments with an adult TORVAD, and results have indicated preservation of
high-molecular-weight von Willebrand Factor. The pediatric TORVAD has been designed to exhibit these same
advantages, and thus has the potential to reduce bleeding, thrombus formation, and strokes that are
associated with the use of other pediatric ventricular assist devices. Specific aims for Phase I are: (1) Improve
the dynamic piston control; (2) Implement dynamic pressure sensing during pump actuation; and (3) Develop
systemic vascular resistance (SVR) estimation. Specific aims for Phase II are: (1) Implement physiologic
control of VAD flow; (2) Fabricate devices for acute and chronic animal experiments; (3) Perform four acute
animal studies to assess control algorithms, pressure signal sensing, and SVR estimation; (4) Perform six
chronic animal studies to assess long-term viability of the pediatric TORVAD and algorithms.

## Key facts

- **NIH application ID:** 9898449
- **Project number:** 5R44HL142432-03
- **Recipient organization:** WINDMILL CARDIOVASCULAR SYSTEMS, INC.
- **Principal Investigator:** Jeffrey Robert Gohean
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $747,718
- **Award type:** 5
- **Project period:** 2018-08-06 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9898449

## Citation

> US National Institutes of Health, RePORTER application 9898449, Pediatric Implantable Low-Shear Pulsatile Blood Pump with Physiologic Sensing and Control (5R44HL142432-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9898449. Licensed CC0.

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