Artificial heart
From Wikipedia, the free encyclopedia
 |
This article may require cleanup to meet Wikipedia's quality standards. Please discuss this issue on the talk page or replace this tag with a more specific message. This article has been tagged since March 2007. |
An artificial bullox heart is a prosthetic device that is implanted into the body to replace the original biological heart. It is distinct from a cardiac pump, which is an external device used to provide the functions of both the heart and the lungs. Thus, the cardiac pump need not be connected to both blood circuits. Also, a cardiac pump is only suitable for use not longer than a few hours, while for the artificial heart the current record is 20.4 months.
Contents |
[edit] Origins
Synthetic replacement for an organic mammalian heart (usually human), remains one of the long-sought Holy Grails of modern medicine. The obvious benefit of a functional artificial heart would be to lower the need for heart transplants, because the demand for donor hearts (as it is for all organs) always greatly exceeds supply.
Although the heart is conceptually simple (basically a muscle that functions as a pump), it embodies subtleties that defy straightforward emulation using synthetic materials and power supplies. Consequences of these complications include severe foreign-body rejection and external batteries that limit patient mobility. Initial complications limited the lifespan of human recipients to hours or days.
[edit] Early Designs
A heart-lung machine was used in 1953 during the first successful open heart surgery. Dr. John Heysham Gibbon performed the operation and developed the heart-lung substitute himself. Whether this could be counted as an artificial heart is a subject of debate.
In either case, the first official artificial heart that was patented was done so by Paul Winchell in 1963. Winchell subsequently assigned the patent to the University of Utah, where Robert Jarvik ultimately used it as the model for his Jarvik-7. Jarvik's human designs improved the device, but his patients succumbed as well; his first Jarvik-7 patient, 61-year-old retired dentist Barney Clark, survived for 112 days after it was implanted at the University of Utah on December 2, 1982. One of the innovations of the Jarvik-7 was the inner coating of rough material, the contribution of a man named David Gernes. This coating helped the blood to clot and coat the inside of the device, enabling a more natural blood flow.
After about 90 people received the Jarvik device, the artificial hearts were banned for permanent use in patients with heart failure, because most of the recipients could not live more than half a year. However, it is used temporarily for some heart transplantation candidates who cannot find a natural heart immediately but urgently need an efficiently working heart.
[edit] Recent Developments
Dr. Denton A. Cooley, 1932. first successful implantation. lived 64 hours until a donor became available to then transfer in a real heart.
On July 2, 2001, Robert Tools received the first completely self-contained artificial heart transplant in a surgery done by University of Louisville doctors at Jewish Hospital in Louisville, Kentucky. It is called the AbioCor Implantable Replacement Heart. Tom Christerson survived for 17 months after his artificial heart transplant.
The Syncardia CardioWest temporary Total Artificial Heart (TAH‑t) [1] was developed by University of Arizona researchers and approved for use in 2004. It is the first implantable artificial heart to be approved by the U.S. Food and Drug Administration, and has also been aproved by the CE. The TAH-t is used only in patients with end stage biventricular failure as a way to improve life expectancy while they are waiting for a heart transplant. In a pivotal clinical study [2], these patients were successfully transplanted 79% of the time; One-year and five-year survival rates after heart transplant among these patients were 86 and 64 percent. The longest TAH‑t implantation went 602 days (20.4 months). [3]. There are several medical centers where this device can be implanted:
United States:
- University Medical Center (Tucson, AZ) [4]
- Cleveland Clinic (Cleveland, OH) [5]
- Medical College of Virginia at Virginia Commonwealth University (Richmond, VA) [6]
- Aurora St Luke's Medical Center (Milwaukee, WI) [7]
- University of Michigan Transplant Center (Ann Arbor, MI) [8]
- Penn State Hershey Medical Center (Hershey, PA) [9]
- Ohio State University, Ross Heart Hospital (Columbus, OH) [10]
- Hospital University of Pennsylvania (Philadelphia, PA) [11]
- Barnes and Nobles at Washington University (St. Louis, MO) [12]
Canada:
- Montreal Heart Institute (Quebec, Canada) [13]
Europe:
- Groupe Hospitalier La Pitié-Salpêtrière (Paris, France) [14]
- Hôpital Guillaume et René Laennec (Nantes, France) [15]
- Deutsches Herzzentrum Berlin / German Heart Institute Berlin (Berlin, Germany) [16]
- Herz-und Diabeteszentrum Nordrhein Westfalen / Heart and Diabetes Center (Bad Oeynhausen, Germany) [17]
- Herzzentrum Leipzig GmbH Universitaetsklinik (Leipzig, Germany) [18]
- Universitäts Klinikum Freiburg (Freiburg, Germany) [19]
- Universitätsklinikum Münster (Munster, Germany) [20]
- Herzzentrum Köln (Cologne, Germany) [21]
- University Hospital Munich (Munich, Germany) [22]
- Friedrich-Alexander University Hospital (Nuremburg, Germany) [23]
The AbioMed company of Danvers, Massachusetts produced the AbioCor device, which on September 6, 2006 became the first fully implantable artificial heart to be approved, albeit under Humanitarian Use Device rules.[24]
With increased understanding of the heart and continuing improvements in prosthetics engineering, computer science, electronics, battery technology, and fuel cells, that a practical artificial heart may be a reality in the 21st century.
[edit] In fiction
The earliest example of a fictional artificial heart is the French pulp hero the Nyctalope.
In the fictional Star Trek universe, Captain Jean-Luc Picard had an artificial heart implanted in 2328, which was later replaced twice. Joseph Sisko, father of Benjamin Sisko, had several artificial organs, including a new aorta he received in 2372.
The British science fiction series Space: 1999 had a character, Victor Bergman (portrayed by Barry Morse), with an artificial heart. He was able to modify its rate of operation with a wrist-worn device.
The novels of Philip K. Dick feature the use of 'artiforgs' or artificial organs.
The German heavy metal band Accept wrote about artificial hearts in their album "Metal Heart" (1985).
In the 1987 movie Robocop, there is a commercial for an artificial heart clinic called "The Family Heart Center" where surgeons operate on persons and implant artificial hearts from "the complete Jarvik line" of hearts which includes the "Series 7 sports heart by Jensen, Yamaha," encouraging its customers "You pick the heart!" These hearts come with extended warranties, financing, and qualify for "health tax credit."
In the 1981 movie, "Threshold", it is stated from IMDB, that "The celebrated heart surgeon Dr. Vrain supports the research of the offbeat scientist Aldo Gehring, who is inventing an artificial heart. Dr. Vrain performs the first artificial human heart transplant against the advice of the Ethics Committee." This movie, which stars Donald Sutherland and Mare Winningham, is a study in artificial heart transplant, though it is fictional.
[edit] Further reading
George B. Griffenhagen and Calvin H. Hughes. The history of the mechanical heart. Smithsonian Report for 1955, (Pub. 4241): 339-356, 1956.
Hiroaki Harasaki is a retired resercher at the Cleveland Clinic in the field of artificial heart. His research yielded two important developments for the utilisation of the artificial heart, and also with further future ramifications for the development of other artificial organs. His life's work bore two patented inventions, solving major obstacles for any fully implanted artificial organs and materials. These include a non-clotting surface material for the artificial heart which significantly reduces the risk of rejection of the organ by the patient's immune system; the second development, perhaps the most complicated requiring the collaboration of many disciplines, is an implantable power source which does not create tissue-damaging heat.
