The United Network for Organ Sharing reported that as of Sept. 24, 2018, nearly 4,000 people in the U.S. were waiting to receive heart transplants. U.S. Department of Health and Human Services data, however, indicates that a typical year produces fewer than 3,000 human hearts from deceased donors, a trend driven largely by medical advances, increased life expectancy and safer automobiles. As a result, you can expect to wait up to two years to get a real, slightly used donor heart. For patients who can’t wait that long, artificial hearts offer a bridge — typically a year or less — to a more permanent heart transplant.
A Longer Life Option
Dr. Peter DeSilva, a board-certified physician in Rancho Santa Margarita, California, and Steve Smith, a biomechanical engineer specializing in pump technology, have a better idea. As co-founders of California Cardiac Solutions, Inc., they are developing an artificial heart that they believe will offer patients a more reliable, more permanent alternative to a heart transplant.
“Early artificial hearts relied on a flexible diaphragm or valves — materials that move back and forth — to simulate the pumping action of the human heart and create what we experience as a pulse,” explained Smith. “Unfortunately these materials are precisely what wears out. Imagine bending a sheet of cardboard back and forth 10,000 times per day, and you’ll see why those early hearts had a limited lifetime.”
By contrast, Smith’s and DeSilva’s new Freedom Heart™ has almost no moving parts. Made from titanium and other biocompatible materials, it is a four-chamber, fully implantable, form-fit-function replacement for the human heart. And it’s designed to last 15 years or more.
Technology Fly Over
The design for the new heart was inspired by work that Smith did earlier in his career as a subcontractor to Northrop Grumman, the developer of the U.S. Air Force’s B-2 stealth bomber. The contractor asked Smith’s company, Fluidic Systems, to develop a pump that could process radar absorption material sprayed on the B-2.
“We needed a pump that could process liquids containing a high concentration of abrasive metal solids without clogging,” said Smith. “We had to eliminate all of the valves and moving components that would normally make the pump work.”
A minor fender bender in his wife’s Jeep in February 2012 put Smith on a collision course with his future. While visiting the body shop, he noticed the latest copy of Popular Science sitting on a table. The cover featured a photo of an artificial heart and the blurb “Human Engine – the 10,000 RPM, Pulseless Heart.”
Smith, who had been fascinated with the human heart his whole life, was smitten. He theorized that his B-2 pump design could be modified to work like an artificial heart. Both applications required a minimum number of moving parts and low shear forces, i.e. minimal friction between the pump surfaces and the fluid to avoid damaging the fluid.
Smith’s personal doctor, DeSilva, confirmed his hunch. The two friends have been collaborating on designs for the Freedom Heart — six generations so far — ever since.
Unlike previous artificial hearts, the Freedom Heart is big on redundancy. It features four tiny, independently controlled impeller pumps and dual redundant electronics throughout. The impellers create the flow and pressure required to push blood through the body.
“If any component of the heart fails,” explained DeSilva, “a bluetooth-enabled chip on the controller boards will place a phone call to the patient and the patient’s doctor,” providing adequate time to repair the heart.
The Road to Clinical Trials
DeSilva and Smith have validated the basic design of their heart with a “bench test” prototype that has been pumping a blood substitute continuously and flawlessly for more than 16 months. They expect to complete assembly of their first implantable prototype this year. Following bench testing, they will move the device to the University of Southern California, where they will test it on animals in collaboration with Dr. Mark Cunningham, a USC heart transplant surgeon, and North American Science Association, a medical research organization. The team hopes to complete the animal studies by late 2019.
DeSilva and Smith do not intend, however, to conduct clinical studies on humans. Instead, they hope California Cardiac Solutions will be acquired by a larger medical devices company with the resources to exploit their medical advances, conduct human trials and bring the device to market.
Freedom for Heart Patients
“Our initial goal was to produce a product that could serve as a bridge to a transplant,” said DeSilva. “We believe, however, that the simple, reliable design of the Freedom Heart may allow patients to use it as a permanent heart replacement, avoid the trauma of future heart surgeries, and live a full and productive life. How’s that for a great outcome?”
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