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The Replacement Heart
The Jarvik-7 is the first device designed to function as a natural heart. Designed by Dr. Robert Jarvik, it was tested in clinical trials for permanent use in patients beginning in 1982. The first patient to receive the implant, Barney Clark, survived for 112 days, while the longest surviving patient, William Schroeder, lived for 620 days.
The Jarvik-7 mimics the heart's function with two air-powered pumps at 40-120 bpm (beats per minute), much like the left and right ventricles. Each chamber has a polyurethane, disk-like mechanism that pushes blood through the device from an inlet valve to an outlet valve. The artificial heart is attached by cuffs to the heart's natural atria via drive-lines made of reinforced polyurethane and coated where they meet the skin to encourage tissue growth.
To operate, the Jarvik-7 requires a large console about the size and weight of a household refrigerator that connects to the pump by drive-lines through the patient's left side. The console controls pump rate, pumping pressure, and other essential functions using electricity, compressed air, and a vacuum. Modified scuba-type onboard air, a rechargeable battery, and wheels provide means for transporting the device and the patient.
While the Jarvik-7 itself is no longer in use, the device is now known as the Cardiowest Total Artificial Heart and is used in selected centers as a bridge to heart transplantation.
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