Artificial Heart Valve
An artificial heart valve is a one-way valve implanted into a person's heart to replace a heart valve that is not functioning properly ( valvular heart disease). Artificial heart valves can be separated into three broad classes: mechanical heart valves, bioprosthetic tissue valves and engineered tissue valves. The human heart contains four valves: tricuspid valve, pulmonary valve, mitral valve and aortic valve. Their main purpose is to keep blood flowing in the proper direction through the heart, and from the heart into the major blood vessels connected to it (the pulmonary artery and the aorta). Heart valves can malfunction for a variety of reasons, which can impede the flow of blood through the valve (stenosis) and/or let blood flow backwards through the valve ( regurgitation). Both processes put strain on the heart and may lead to serious problems, including heart failure. While some dysfunctional valves can be treated with drugs or repaired, others need to be replaced with ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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One-way Valve
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves are often part of common household items. Although they are available in a wide range of sizes and costs, check valves generally are very small, simple, and inexpensive. Check valves work automatically and most are not controlled by a person or any external control; accordingly, most do not have any valve handle or stem. The bodies (external shells) of most check valves are made of plastic or metal. An important concept in check valves is the cracking pressure which is the minimum differential upstream pressure between inlet and outlet at which the valve will operate. ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Heart Attack
A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom is retrosternal Angina, chest pain or discomfort that classically radiates to the left shoulder, arm, or jaw. The pain may occasionally feel like heartburn. This is the dangerous type of acute coronary syndrome. Other symptoms may include shortness of breath, nausea, presyncope, feeling faint, a diaphoresis, cold sweat, Fatigue, feeling tired, and decreased level of consciousness. About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an Cardiac arrhythmia, irregular heartbeat, cardiogenic shock or cardiac arrest. Most MIs occur d ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Aortic Karboniks-1 Bileafter Prosthetic Heart Valve
The aorta ( ; : aortas or aortae) is the main and largest artery in the human body, originating from the left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at the aortic bifurcation into two smaller arteries (the common iliac arteries). The aorta distributes oxygenated blood to all parts of the body through the systemic circulation. Structure Sections In anatomical sources, the aorta is usually divided into sections. One way of classifying a part of the aorta is by anatomical compartment, where the thoracic aorta (or thoracic portion of the aorta) runs from the heart to the diaphragm. The aorta then continues downward as the abdominal aorta (or abdominal portion of the aorta) from the diaphragm to the aortic bifurcation. Another system divides the aorta with respect to its course and the direction of blood flow. In this system, the aorta starts as the ascending aorta, travels superiorly from the heart, an ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Pyrolytic Carbon
Pyrolytic carbon is a material similar to graphite, but with some covalent bonding between its graphene sheets as a result of imperfections in its production. Pyrolytic carbon is man-made and is thought not to be found in nature.Ratner, Buddy D. (2004). Pyrolytic carbon. In Biomaterials science: an introduction to materials in medicine'. Academic Press. p. 171–180. . Google Book Search. Retrieved 7 July 2011. Generally it is produced by heating a hydrocarbon nearly to its decomposition temperature, and permitting the graphite to crystalize (pyrolysis). One method is to heat synthetic fibers in a vacuum, producing carbon fibers. It is used in high temperature applications such as missile nose cones, rocket motors, heat shields, laboratory furnaces, in graphite-reinforced plastic, coating nuclear fuel particles, and in biomedical prostheses. It was developed in the late 1950s as an extension of the work on refractory vapor deposition of metals. Physical properties Pyr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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EPTFE
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally invented the compound in 1938. Polytetrafluoroethylene is a fluorocarbon solid, as it is a high- molecular-weight polymer consisting wholly of carbon and fluorine. PTFE is hydrophobic: neither water nor water-containing substances wet PTFE, as fluorocarbons exhibit only small London dispersion forces due to the low electric polarizability of fluorine. PTFE has one of the lowest coefficients of friction of any solid. Polytetrafluoroethylene is used as a non-stick coating for pans and other cookware. It is non-reactive, partly because of the strength of carbon–fluorine bonds, so it is often used in containers and pipework for reactive and corrosive chemicals. When used as a lubricant, PTFE reduces friction, w ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Check Valve
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves are often part of common household items. Although they are available in a wide range of sizes and costs, check valves generally are very small, simple, and inexpensive. Check valves work automatically and most are not controlled by a person or any external control; accordingly, most do not have any valve handle or stem. The bodies (external shells) of most check valves are made of plastic or metal. An important concept in check valves is the cracking pressure which is the minimum differential upstream pressure between inlet and outlet at which the valve will operate ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Chitra Valve
Chitra may refer to: Art * Chitra (art), a historic art that includes paintings, sketching with or without multiple colors People * Chithra, Indian playback singer * Chitra (actress), Indian film actress (1965-2021) * V. J. Chitra, Indian television actress (1992-2020) * Chitra Bahadur K.C., Nepalese politician * Chitra Banerjee Divakaruni (born 1956), Indian-American author, poet, and professor of English * Chitra Bharucha (born 1945), former Consultant Haematologist and Vice Chair of the BBC Trust * Chitra Dewi (1934–2008), Indonesian actress * Chitra Ganesh (born 1975), artist based in Brooklyn, New York * Chitra Jeremiah (born 1971), Nauruan diplomat * Chitra Lekha Yadav, Nepalese politician * Chitra Mudgal (born 1944), literary figure in modern Hindi literature * Chitra Sarwara (born 1975), Indian politician from Haryana * Chitra Singh (born 1945), female ghazal singer * Chitra Soman (born 1983), Indian sprinter * Chitra Subramaniam (born 1958), Indian journalis ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Prothrombin Time
The prothrombin time (PT) – along with its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) – is an assay for evaluating the Coagulation#Extrinsic pathway, extrinsic pathway and Coagulation#Common pathway, common pathway of coagulation. This blood test is also called ''protime INR'' and ''PT/INR''. They are used to determine the Thrombophilia, clotting tendency of blood, in conditions such as the measure of warfarin dosage, liver damage (cirrhosis), and vitamin K status. PT measures the following Coagulation#Coagulation factors, coagulation factors: fibrinogen, I (fibrinogen), thrombin, II (prothrombin), Factor V, V (proaccelerin), Factor VII, VII (proconvertin), and Factor X, X (Stuart–Prower factor). PT is often used in conjunction with the partial thromboplastin time, activated partial thromboplastin time (aPTT) which measures the Coagulation#intrinsic pathway, ''intrinsic'' pathway and common pathway of coagulation. Laboratory measur ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Anticoagulation
An anticoagulant, commonly known as a blood thinner, is a chemical substance that prevents or reduces the coagulation of blood, prolonging the clotting time. Some occur naturally in blood-eating animals, such as leeches and mosquitoes, which help keep the bite area unclotted long enough for the animal to obtain blood. As a class of medications, anticoagulants are used in therapy for thrombotic disorders. Oral anticoagulants (OACs) are taken by many people in pill or tablet form, and various intravenous anticoagulant dosage forms are used in hospitals. Some anticoagulants are used in medical equipment, such as sample tubes, blood transfusion bags, heart–lung machines, and dialysis equipment. One of the first anticoagulants, warfarin, was initially approved as a rodenticide. Anticoagulants are closely related to antiplatelet drugs and thrombolytic drugs by manipulating the various pathways of blood coagulation. Specifically, antiplatelet drugs inhibit platelet aggregation ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Poly(methyl Methacrylate)
Poly(methyl methacrylate) (PMMA) is a synthetic polymer derived from methyl methacrylate. It is a transparent thermoplastic, used as an engineering plastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Walcast, Hesalite, Plexiglas, Acrylite, Lucite, PerClax, and Perspex, among several others ( see below). This plastic is often used in sheet form as a lightweight or shatter-resistant alternative to glass. It can also be used as a casting resin, in inks and coatings, and for many other purposes. It is often technically classified as a type of glass, in that it is a non-crystalline vitreous substance—hence its occasional historic designation as ''acrylic glass''. History The first acrylic acid was created in 1843. Methacrylic acid, derived from acrylic acid, was formulated in 1865. The reaction between methacrylic acid and methanol results in the ester methyl methacrylate. It was developed in 1928 in several different la ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Albert Starr
Albert Starr (June 1, 1926 – December 11, 2024) was an American cardiovascular surgeon and was the first surgeon to successfully implant the Starr-Edwards heart valve surgically. Starr resided and practiced in the Portland, Oregon, area and was special adviser to OHSU Dean of Medicine Mark Richardson and OHSU President Joseph Robertson (OHSU) at Oregon Health and Science University. He worked closely with the inventor of the Star-Edwards heart valve, Miles “Lowell” Edwards, to test the device and ensure its safety before its first use. Life and career Starr was born in New York, New York, on June 1, 1926. He received his B.A. degree from Columbia College (now Columbia University) in 1946 and his M.D. degree from Columbia College of Physicians and Surgeons in 1949. He then went on to do his internship at Johns Hopkins Hospital and his residency in general and thoracic surgery at the Bellevue and Presbyterian Hospitals of Columbia University. He was an assistant in surg ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |