Methods to Wirelessly Power Fully Implantable Intravascular Blood Pumps

Mechanical circulatory support (MCS) devices, like implantable blood pumps, have served as an effective therapy option for patients with end-stage heart failure for over the last two decades. Within the last decade, MCS therapy has shifted from a bridge-to-transplant option to a destination therapy alternative. A large part of this success is attributed to the advancements in blood pump technology. Particularly, the development of percutaneous intravascular blood pumps, devices that can be implanted via catheter procedures, has enabled the rapid deployment of MCS in patients with acute decompensated heart failure and cardiogenic shock. Utilization of these miniature devices for long-term use is hindered by the purge line and power cord that connect the intravascular device to external components. Eliminating both of the connections will enable the use of intravascular pumps in a wider population of heart failure patients. The overall goal of this research is provide a roadmap for eliminating the power cord that tethers the intravascular device to an external power supply. Powering intravascular devices offers a unique challenge in that the strategy to provide continuous power to such a device must take into consideration the depth of implantation and the physiological structures in between the external source and the device. In the case for intravascular pumps, the pump and any other components must sit in vasculature, which may be a few centimeters from the surface of the skin, and provide unobstructed flow of blood from the pump to the organs or lungs. In order to close this gap, we will utilize thin-film inductor coils in a multi-resonator configuration, to provide wireless power over a distance ranging from 10-50 mm. This approach will use a transmitter coil, located external to the patient, an intermediate external resonator coil, an intermediate implanted resonator coil, and an implanted receiver coil fixed to an implantable stent to provide power to an intravascular pump. The intravascular pump designed by the PI in previous research will be used. In order to achieve the overarching goal, we have outlined three specific aims. Specific Aim #1: Define and quantify the variables that affect the magnetic coupling between multiple low-profile coils across a range of clinically relevant distances, configurations, and tissues using finite element modeling. Hypothesis: Appropriately modeling and predicting the magnetic coupling between external and implanted thin-film resonators will give quantitative insight into the limiting factors and design constraints of multiple resonators implanted in the body for providing wireless power to intravascular pumps. This modeling will be done using finite element modeling software, which provides mathematical solvers and steady-state and frequency-domain solutions to electric and magnetic field problems. Specific Aim #2: Validate the multi-resonator wireless powering approach by fabricating flexible planar inductors and determining wireless transfer capabilities through phantom tissue over clinically relevant distances and configurations. Hypothesis: Quantifying the interaction between resonators experimentally will shed light on the geometric configurations that are feasible when translating this wireless power approach to a clinical setting. Utilizing multiple flexible copper laminate coils provides the most efficient yet minimally invasive solution to wirelessly power and intravascular pump through a few centimeters of tissue and blood. Specific Aim #3: Demonstrate continuous wireless power capability to a blood pump by incorporating the resonators in a wireless power system and providing continuous power to an intravascular blood pump in a mock circulation that mimics the hemodynamics of a heart failure patient. Hypothesis: Testing the multi-resonator methodology using thin-film coils in a clinically relevant test rig will highlight the physiologic parameters that affect the wireless powering methodology. Providing wireless power through a tissue-phantom and to an intravascular blood pump that is running in a pulsatile environment will accurately predict the performance of a multi-resonator wireless powering system using thin-film inductor coils. Achieving these three aims will provide engineers and researchers a methodology for developing smaller MCS systems for long-term support. Clinically, developing a fully-implantable intravascular pump will give patients with a variety of congestive or congenital heart problems a long-term therapeutic option for alleviating their disease. This research will also strengthen the environment at CSUN by exposing undergraduate and graduate students to multi-disciplinary and clinically relevant research.