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Amanda junkins Bme 281 University of rhode island October 2, 2012. Artificial Hearts. What is an Artificial Heart?. Total Artificial Heart – device that replaces at least the lower two chambers (ventricles) of the heart and fully takes over cardiac function
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Amanda junkins Bme 281 University of rhode island October 2, 2012 Artificial Hearts
What is an Artificial Heart? • Total Artificial Heart – device that replaces at least the lower two chambers (ventricles) of the heart and fully takes over cardiac function • Often used to bridge the time between heart failure and heart transplantation • Can be used for permanent replacement if transplant is not possible
History • 1940’s-1950’s – early designs of artificial heart machines; used only to keep patient’s blood flowing while the real heart was operated on • Late 1950’s-1970’s – artificial hearts tested on animals, primarily dogs and cows • 1961 – Dr. Domingo Liotta reported on three types of total artificial hearts with different sources of external energy: an implantable electric motor, an implantable rotating pump with an external electric motor, and a pneumatic pump • 1969 – Liotta-Cooley Total Artificial Heart, first clinical use • 1982 – the Jarvik 7 artificial heart was implanted into a human being and successful for nearly four months
The Jarvik 7 • Developed by Dr. Robert Jarvik and Dr. Willem Johan Kolff, starting in 1971 • Originally made of a material that the human body would not accept, ended up using aluminum and plastic, with two rubber diaphragms for the pumping action • The external compressor that kept the heart beating was the size of a refrigerator – mobility problems • Even with the highest success rate (79%), and embolism and infection adequately controlled, there was a great need for a completely implantable heart
Newer Models • SynCardia Systems Temporary TAH – modeled like the Jarvik 7, with a slightly smaller tube diameter • Used for the time between heart failure in both ventricles (irreversible end stage biventricular failure) and heart transplant • By 2010, this model included a portable appliance that kept the device running, that was just the size of a fanny pack, allowing patients awaiting a transport to leave the hospital environment
Newer Models • AbioCor Replacement Heart – fully implantable artificial heart, meaning there are no external tubes or wires penetrating the skin, so there is less risk for infection • Used in patients with biventricular heart disease, who are ineligible for a heart transplant and have no other viable options of treatment • AbioCor runs on a rechargeable source of power, called transcutaneous energy transmission
Advantages/Disadvantages • Jarvik 7 – highest success rate of all artificial hearts, able to sustain patients between heart failure and heart transplant, no mobility for the patient • SynCardia Systems TAH – smaller, allows for movement with fanny pack sized battery, can’t sustain the patient as long as the Jarvik 7 • AbioCor – bigger (more suited for a larger male), fully implantable with less risk of infection, made to be permanent but typically keeps patient alive for 18 months
Ethical Considerations • Patients with total heart failure have very little time to live, and are often suffering. How does one deal with the situation where a patient asks to be allowed to die? • Organ/Heart Transplantation – taking one person’s heart and putting it into another person’s body
In the Future • 2011 – The Berlin Heart – more of a ventricular assist device (VAD), designed for children, now FDA approved • Carmat artificial heart – from the French biomedical firm Carmat, fully implantable TAH, uses electronic sensors and is made from chemically treated animal tissues (biomaterials), clinical trials in 2012/2013
References • Advameg, Inc.. "How artificial heart is made - history, used, parts, components, industry, machine, History, Raw Materials, Design, The Manufacturing Process of artificial heart, Quality Control, Byproducts/Waste." How Products Are Made. N.p., n.d. Web. <http://www.madehow.com/Volume-6/Artificial-Heart.html>. • "Artificial heart - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. N.p., n.d. Web. <http://en.wikipedia.org/wiki/Artificial_heart>. • Greatrex, Nicholas. "Axial Magnetic Bearing Development for the BiVACOR Rotary BiVAD/TAH." IEEE Transactions on Biomedical Engineering 57.3 (2010): 714-721. IEEE Xplore. Web. • "Jarvik Heart | Resources - Robert Jarvik on the Jarvik-7." Jarvik Heart | Home - Welcome. N.p., n.d. Web. <http://www.jarvikheart.com/basic.asp?id=69>.